Radiological Conditions at the Former French Nuclear Test Sites in Algeria:Preliminary Assessment and Recommendations

RADIOLOGICALASSESSMENTR E P O R T SS E R I E S

The cover photograph shows the area at Taourirt Tan Afella where nuclear explosions were performed from1961 to 1966.

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RADIOLOGICAL CONDITIONS ATTHE FORMER FRENCH NUCLEAR

TEST SITES IN ALGERIA:PRELIMINARY ASSESSMENTAND RECOMMENDATIONS

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AFGHANISTANALBANIAALGERIAANGOLAARGENTINAARMENIAAUSTRALIAAUSTRIAAZERBAIJANBANGLADESHBELARUSBELGIUMBENINBOLIVIABOSNIA AND HERZEGOVINABOTSWANABRAZILBULGARIABURKINA FASOCAMEROONCANADACENTRAL AFRICAN REPUBLICCHILECHINACOLOMBIACOSTA RICACÔTE D’IVOIRECROATIACUBACYPRUSCZECH REPUBLICDEMOCRATIC REPUBLIC OF THE CONGODENMARKDOMINICAN REPUBLICECUADOREGYPTEL SALVADORERITREAESTONIAETHIOPIAFINLANDFRANCEGABONGEORGIAGERMANYGHANA

GREECEGUATEMALAHAITIHOLY SEEHONDURASHUNGARYICELANDINDIAINDONESIAIRAN, ISLAMIC REPUBLIC OF IRAQIRELANDISRAELITALYJAMAICAJAPANJORDANKAZAKHSTANKENYAKOREA, REPUBLIC OFKUWAITKYRGYZSTANLATVIALEBANONLIBERIALIBYAN ARAB JAMAHIRIYALIECHTENSTEINLITHUANIALUXEMBOURGMADAGASCARMALAYSIAMALIMALTAMARSHALL ISLANDSMAURITANIAMAURITIUSMEXICOMONACOMONGOLIAMOROCCOMYANMARNAMIBIANETHERLANDSNEW ZEALANDNICARAGUANIGERNIGERIANORWAYPAKISTANPANAMA

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Printed by the IAEA in AustriaMarch 2005

STI/PUB/1215

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RADIOLOGICAL CONDITIONS ATTHE FORMER FRENCH NUCLEAR

TEST SITES IN ALGERIA:PRELIMINARY ASSESSMENTAND RECOMMENDATIONS

RADIOLOGICAL ASSESSMENT REPORTS SERIES

INTERNATIONAL ATOMIC ENERGY AGENCYVIENNA, 2005

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IAEA Library Cataloguing in Publication Data

Radiological conditions at the former French nuclear test sites in Algeria :preliminary assessment and recommendations. — Vienna :International Atomic Energy Agency, 2005.

p. ; 29 cm. — (Radiological assessment reports series, ISSN1020-6566)

STI/PUB/1215ISBN 92–0–113304–9Includes bibliographical references.

1. Radiation — Algeria — Safety measures. 2. Nuclear weapons —Algeria — Testing. 3. Radioactive pollution — Algeria. 4. Algeria —Environmental conditions. I. International Atomic Energy Agency.II. Series.

IAEAL 05–00392

FOREWORD

There are various locations around the world that have been affected by radioactive residues. Some ofthese residues are the result of past peaceful activities, while others result from military activities, includingresidues from the testing of nuclear weapons. Stimulated by concern about the state of the environment,movement away from military nuclear activities and improved opportunities for international cooperation,attention in many countries has turned to assessing and, where necessary, remediating areas affected byradioactive residues.

Some of these residues are located in countries where there is a lack of the infrastructure or expertisenecessary for evaluating the significance of the radiation risks posed by the residues and for making decisions onremediation. In such cases, governments have felt it necessary to obtain outside assistance. In other cases, it hasbeen considered socially and politically necessary to have independent expert opinions on the radiologicalsituation at the sites. As a result, the International Atomic Energy Agency (IAEA) has been requested by thegovernments of a number of Member States to provide assistance in relation to its statutory obligation “toestablish…standards of safety for protection of health…and to provide for the application of thesestandards…at the request of a State”.

On 22 September 1995, a resolution of the General Conference of the IAEA called on all States “to fulfiltheir responsibilities to ensure that sites where nuclear tests have been conducted are monitored scrupulouslyand to take appropriate steps to avoid adverse impacts on health, safety and the environment as a consequenceof such nuclear testing”.

Representatives of the Algerian Government requested the IAEA to carry out a study of the radiologicalsituation at the former French nuclear test sites in Algeria. The findings of this assessment are summarized inthis report.

BLANK PAGE

CONTENTS

SUMMARY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

1. TEST SITES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

2. BACKGROUND ON THE NUCLEAR TESTING PROGRAMME IN ALGERIA. . . . . . . . . . . . . 5

2.1. Historical information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52.2. Pre-survey estimation of the current radiological situation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

2.2.1. Gerboise atmospheric tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52.2.2. Underground tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

2.2.2.1. Béryl test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132.2.2.2. Améthyste test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

2.2.3. Experiments with plutonium pellets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 152.2.4. Pollen experiments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

3. IAEA MISSION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

3.1. Mission team . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 173.2. Mission itinerary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

4. SAMPLING AND MEASUREMENT PROGRAMME . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

4.1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 194.1.1. Reggane . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 194.1.2. In Ekker (Taourirt Tan Afella and Adrar Tikertine) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

4.2. Field measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 194.3. Field sampling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

4.3.1. Soil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 204.3.2. Water . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 204.3.3. Vegetation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

4.4. Results of sampling and measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 204.4.1. Field measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

4.4.1.1. Reggane. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 204.4.1.2. In Ekker — Taourirt Tan Afella . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 244.4.1.3. In Ekker — Adrar Tikertine. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

4.4.2. Laboratory measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 254.4.3. Major conclusions based on the laboratory measurements . . . . . . . . . . . . . . . . . . . . . . . . . 26

4.4.3.1. Samples from Reggane . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 264.4.3.2. Samples from In Ekker — Taourirt Tan Afella . . . . . . . . . . . . . . . . . . . . . . . . . . . 274.4.3.3. Samples from In Ekker — Adrar Tikertine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

5. ESTIMATES OF PRESENT AND FUTURE DOSES TO PERSONS ARISING FROM RESIDUAL RADIOACTIVE MATERIAL AT THE SITES . . . . . . . . . . . . . . . . . . . . . . . . . 28

5.1. General methodology for calculating doses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 285.2. Sources and pathways of exposure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

5.2.1. Atmospheric test site at Reggane . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 285.2.2. Underground test site at In Ekker — Taourirt Tan Afella . . . . . . . . . . . . . . . . . . . . . . . . . 295.2.3. Adrar Tikertine experimentation site . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

5.3. Radiation doses due to residues from nuclear testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 295.3.1. Reggane atmospheric test site . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

5.3.2. In Ekker — Taourirt Tan Afella underground test site . . . . . . . . . . . . . . . . . . . . . . . . . . . . 305.3.3. Adrar Tikertine experimentation site . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

6. CONCLUSIONS AND RECOMMENDATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

6.1. General discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 326.2. Specific conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

6.2.1. Reggane . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 326.2.2. Taourirt Tan Afella . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 326.2.3. Adrar Tikertine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

6.3. Recommendations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

APPENDIX I: DETERMINATION OF 90Sr, 241Am, Pu AND GAMMA EMITTING RADIONUCLIDES IN THE SAMPLES COLLECTED IN ALGERIA . . . . . . . . . . . 35

I.1. Radioisotopes analysed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35I.2. Sample description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35I.3. General procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35I.4. Analytical procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35I.5. Results and discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43I.6. Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44I.7. Personnel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

APPENDIX II: ASSESSMENT OF RADIATION DOSES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47

II.1. Reggane . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47II.2. In Ekker — Taourirt Tan Afella . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49II.3. In Ekker — Adrar Tikertine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52

APPENDIX III: RADIOLOGICAL CONCEPTS IN THE CONTEXT OF NUCLEAR WEAPON TESTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53

III.1. Radiological quantities and units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53III.2. Radiological releases due to testing of nuclear weapons . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54III.3. Health effects of radiation exposure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55

APPENDIX IV: RADIATION PROTECTION CRITERIA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56

IV.1. General considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56IV.2. Generic intervention levels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56IV.3. Guidelines that may be applicable to chronic exposure situations . . . . . . . . . . . . . . . . . . . . . . . . . 57IV.4. Reference for comparison: Doses due to natural background radiation . . . . . . . . . . . . . . . . . . . . 58IV.5. Generic guidance for rehabilitation of areas of chronic exposure . . . . . . . . . . . . . . . . . . . . . . . . . 58

REFERENCES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59

SUMMARY

Following a request by the Government ofAlgeria, the International Atomic Energy Agency(IAEA) conducted an expert mission in late 1999 tosites in Algeria that had been used by France in theearly 1960s for the testing of nuclear weapons. TheIAEA mission international team was made up offive experts in performing radiological assessments.

The terms of reference for the mission were:

— “make a preliminary assessment of thepresent radiological situation of the Reggane(atmospheric tests) and In-Ekker test sites(underground nuclear test site and radioactivewaste sites) by performing radioactivitymeasurements at the sites and at selectedinhabited locations, i.e., external dose rates, in-situ gamma spectroscopy.

— Selected environmental and food samplesshould be collected and subsequentlyanalysed.

— The results of these measurements should beused to set up a plan to monitor the test sitesmore comprehensively, if justified, and toperform a preliminary dose assessment.”

The team of experts, composed of membersfrom France, New Zealand, Slovenia, the UnitedStates of America and the IAEA, was supportedand assisted by a group of seven experts from theAlgerian Commissariat à l’énergie atomique.During the course of an eight day mission, thesites of both above ground tests (Reggane site)and underground tests (In Ekker sites) weremonitored for dose rates that resulted fromresidual radioactive material (fission andactivation products). Samples of environmentalmedia, i.e. sand, fused sand, solidified lava,vegetation and well water, were collected andanalysed in the IAEA’s Laboratories in Seibers-dorf, Austria.

The mission was able to achieve more thanexpected as a consequence of the detailedinformation provided by France. The informationwas essential for understanding the kinds anddegree of contamination.

All known locations of nuclear test sites inAlgeria (Reggane and In Ekker — Taourirt TanAfella and Adrar Tikertine) were included in the

mission. The overall findings and conclusions fromthe fact finding mission were:

(a) Most of the areas at the test sites have littleresidual radioactive material except:— The ground zero localities of the Gerboise

Blanche and Gerboise Bleue atmospherictests at the Reggane test site;

— At Taourirt Tan Afella in the vicinity of theE2 tunnel.

(b) External dose rate measurements were madeat 76 locations. A total of 25 environmentalsamples were collected. While the number ofdose rate measurements was consideredadequate, the number of samples collectedand analysed was somewhat small, in view ofthe size of the areas.

(c) According to the generally conservativescenarios assumed and the exposure pathwaysused, and on the basis of the results of doserate measurements and analysis of a limitednumber of samples, there is no indication thatfor any of the sites (with the possibleexception of the Gerboise Bleue, GerboiseBlanche and E2 tunnel sites) annualexposures might occur in excess of anyaccepted international guideline values forexposure of the public.

(d) A single location (the E2 gallery at TaourirtTan Afella), at the opening of one of thepartially confined underground tests where anaccidental release of fission products mixedwith molten rock took place and formed alarge bed of hardened lava, has beenprotected from public intrusion by a securityfence. Maintenance of that fence is advocatedin the interest of keeping public exposures aslow as reasonably achievable.

(e) A more detailed and comprehensive radio-logical survey does not appear necessary forany of the sites if there is no social oreconomic development in the region ofinterest.

(f) Corroboration and support of the generalconclusions stated here could nevertheless beprovided by an appropriate level of radio-logical surveillance activities, to be conductedby the Algerian authorities, e.g. monitoring air

1

concentrations in and around the populatedvillages closest to the above ground test sites.

(g) Despite the preliminary nature of thesampling and investigation programme, allconclusions indicate that present-dayexposure rates do not justify a requirement forintervention, in view of the current state ofdevelopment of the region. This would notpreclude the Algerian authorities fromcarrying out remediation or preventing accessto the sites for other reasons. However, if theeconomic conditions change in the area, therequirement for intervention at the GerboiseBleue, Gerboise Blanche and E2 tunnel sitesshould be reconsidered.

(h) A more precise estimate of the doses tomigrant and nomadic people of the Algeriandesert could be developed by obtaining amore accurate and quantitative description oftheir lifestyles, habits, food collectionmethods, etc.

Appendix I provides details of the analyticalprocedures and results for the samples that werecollected at the test sites. Appendix II provides anassessment of the radiation doses. Appendix IIIprovides general radiological concepts in thecontext of nuclear weapon testing. Appendix IVprovides general radiation criteria for interventionsituations.

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1. TEST SITES

In the early 1960s, France conducted a seriesof above ground and underground nuclear tests, atthe Reggane and In Ekker sites, respectively, in thesouth of Algeria. Figure 1 shows the locations of thesites. These nuclear explosions resulted in releasesof radioactive material to the environment.

The Reggane test sites are located in thedesert (an area of only sand and rocks) about 50 kmsouth of Reggane, which is an oasis village of a fewthousand inhabitants situated about 150 km southof Adrar, a city with approximately 50 000 inhab-itants. Access to the area of the test sites is restrictedby military control. There are practically no roadsleading to these sites. The old roads formerly usedby the French military have now nearly disap-peared. This is due to the demolition of the roadswhen the French forces left the area. This region isperiodically affected by sandstorms.

In the In Ekker region there are two sites thatwere used for nuclear experiments. The first site iscalled Taourirt Tan Afella, from the name of the

granite mountain (about 2000 m high) where thetunnels that were used for the nuclear weapon testswere excavated. The second site is Adrar Tikertine,named after a granite mountain about 1250 m highwhich is adjacent to the site.

The test site of Taourirt Tan Afella is locatedwithin the Hoggar mountains, about 140 km northof Tamanrasset, a city of about 30 000 inhabitantsthat lies at an altitude of 1000 m and is located about2000 km south of Algiers and about 500 km north ofthe border with Niger. At this site, all nuclear testswere conducted in tunnels. One of the test sitetunnels is surrounded by a fence that is in a state ofdeterioration, and therefore the area is easy toenter. The local authorities are now constructing amuch larger fence that will encircle the Taourirt TanAfella mountain.

The Adrar Tikertine site lies about 30 kmwest of the Taourirt Tan Afella mountain. At theAdrar Tikertine site, experiments on the dispersionof plutonium in air (the ‘Pollen’ experiments) were

FIG. 1. Location of test sites. CEMO: Centre d’expérimentations militaires des oasis; CSEM: Centre saharien d’expérimenta-tions militaires.

3

conducted. There are practically no roads leadingto the area, and the terrain is rocky and traversedby dry stream beds. This makes for slow access andvery difficult identification. On approaching thesite, sparse vegetation is seen and there is a waterwell. Then the vegetation becomes scarcer, sandand rocks prevail, and the terrain is scarred by dry

stream beds clearly indicating that from time totime there are torrential rains and the areabecomes flooded (this was confirmed by localpeople). At the site of the Pollen experiments thereis only sand and the granite mountain of AdrarTikertine. There are many other granite hills in thenearby area.

4

2. BACKGROUND ON THE NUCLEAR TESTING PROGRAMME IN ALGERIA

The information set forth in this section wasprovided to the IAEA mission by the Frenchauthorities at the request of the IAEA. Theinformation includes historical radiological datathat were pertinent to the survey and estimates ofthe radiological conditions prevailing in 1999 priorto the IAEA mission. The estimates were extra-polated by the French authorities from data whichare unpublished and not available to the public.

2.1. HISTORICAL INFORMATION

France performed 17 nuclear tests in theSahara Desert between 1960 and 1966; the first fourtests were atmospheric and the following 13 wereunderground.

The atmospheric tests named Gerboise(Bleue, Blanche, Rouge and Verte) wereundertaken in 1960 and 1961 at the Centre sahariend’expérimentations militaires (CSEM), the SaharanMilitary Test Centre. This centre was set up aroundthe Reggane Oasis (Fig. 2), situated in the heart ofthe southern Sahara to the south of the WesternGrand Erg, 700 km south-east of Béchar.

Between 1961 and 1963, 35 experiments wereperformed on plutonium pellets at the CSEM, nearground zero of the Gerboise Rouge test (Fig. 2).

The underground tests, whose code nameswere those of precious stones (Agate, Béryl,Emeraude, Améthyste, Rubis, Opale, Topaze,Turquoise, Saphir, Jade, Corindon, Tourmalineand Grenat) were carried out between 1961 and1966 at the Centre d’expérimentations militairesdes oasis (CEMO), the Oasis Military Test Centre(Figs 3 and 4). The tests were performed at theends of tunnels dug into the Taourirt Tan Afellamassif, a granite mountain measuring 5000 m by3700 m that is situated 140 km north-west ofTamanrasset.

Between 1964 and 1966 at the CEMO, fiveplutonium dispersal experiments code namedPollen were performed to the north-west of theTaourirt Tan Ataram massif near Adrar Tikertine(Fig. 3).

2.2. PRE-SURVEY ESTIMATION OF THE CURRENT RADIOLOGICAL SITUATION

Prior to the field mission of November 1999,data covering the period of activity of the two testcentres from more than thirty years earlier wereextrapolated to estimate the ‘current’ radiologicalsituation (throughout this report, ‘current’, ‘present’and ‘now’ refer to 1999). This estimation wasconducted to guide the implementation of the fieldsurvey, in particular to indicate the level of exposureexpected.

The hypotheses and results obtained fromextrapolation of historical data must be consideredwith caution, taking into account that the activitymeasurement techniques used in the 1960s were notas precise as those used today. This is the case, forexample, with gamma spectrometry that used NaIscintillation detectors whose performance levels(identification, detection and precision) were farlower than those of the present-day germaniumsemiconductor detectors.

To evaluate the residual activity due to theatmospheric nuclear tests and the partially confinedunderground tests performed on the Saharan sites,the measurements made at the time of the nucleartests were extrapolated to the present day from theisodose rate curves at H + 11 .

2.2.1. Gerboise atmospheric tests

The Gerboise test zone is a desert areasituated some 50 km south of Reggane, an oasislocated to the south of the Western Grand Erg and700 km from Béchar.

Three of the atmospheric tests (GerboiseBleue, Gerboise Rouge and Gerboise Verte) werecarried out on a tower, while the test at GerboiseBlanche was performed on the ground (Table 1).

1 H + 1 represents time one hour after detonation.The isodose rate curves at H + 1 are synthetic curveswhich were based on aerial and terrestrial measurementscarried out periodically after the fallout, and recalculatedback to a reference time (H + 1 h).

5

FIG. 2. Map showing Reggane, the location of the CSEM, and the locations of the four Gerboise atmospheric nuclear tests andthe pellet experiments.

6

The total explosive yield released in the four testswas between 40 and 110 kt TNT equivalent.

Estimates of the current radiological situationwere developed from the isodose rate curves atH + 1 (Figs 5–8), applying to them a theoreticalattenuation coefficient of the order of 2 × 107,defined as follows:

(a) The dose rate resulting from an unfrac-tionated mixture of fission products decays by

a factor of 0.8 × 107 between H + 1 and 38years owing to radioactive decay.

(b) In the 38 years that have elapsed, the dose ratehas decayed by an additional factor of theorder of 2, owing to the dispersion of the finestcontaminated particles by the wind.

(c) An additional attenuation factor of the orderof 20% is used to take into account thepresence of activation products in the initialdose rates measured at H + 1.

FIG. 3. Map showing the locations of the tests in the Taourirt Tan Afella massif and near the Taourirt Tan Ataram massif·(CEMO).

TABLE 1. ATMOSPHERIC NUCLEAR TESTS CONDUCTED AT REGGANE

Test Date Longitude Latitude TypeYield, W

(kt)

Gerboise Bleue 1960-02-13 0°03'26" W 26°18'42" N Tower, 100 m 40 < W < 80

Gerboise Blanche 1960-04-01 0°06'09" W 26°09'58" N Surface W < 10

Gerboise Rouge 1960-12-27 0°07'25" W 26°21'13" N Tower, 50 m W < 10

Gerboise Verte 1961-04-25 0°04'24" W 26°19'18" N Tower, 50 m W < 10

7

1 km0

FIG. 4. Map showing the locations of the tunnel entrances for the underground tests in the Taourirt Tan Afella massif (CEMO).

8

The 1999 dose rate evaluations for the vicinityof the Gerboise ground zero points are given inFig. 9, along with the surface areas of the falloutzones.

The current dose rates are essentially due to137Cs (in fact to its decay product 137mBa), with theother fission or activation products not contributingmore than 5% to the present dose rate. Theevaluated surface activity of 137Cs in soil in 1999 is

shown in Fig. 9, using the relation 2.5 × 10–12 Gy/hper Bq/m2 of 137Cs (i.e. 1 mGy/h per 0.4 MBq/m2 of137Cs). The residual surface activities of 137Cs shouldthen be between:

— 0.02 and 2.0 MBq/m2 over a surface area ofabout 1 km2 for Gerboise Bleue;

— 0.02 and 3.0 MBq/m2 over a surface area ofabout 1 km2 for Gerboise Blanche;

— 0.02 and 0.2 MBq/m2 over a surface area ofabout 0.2 km2 for Gerboise Rouge;

— 0.02 and 0.2 MBq/m2 over a surface area ofabout 0.2 km2 for Gerboise Verte.

The areas of the Gerboise Bleue and GerboiseBlanche tests display the highest surface activities of137Cs. The Gerboise Blanche test performed on theground produced a crater that was later filled in.

N

0 200 400 600 800 m

30

10

1

0.1

0.01

FIG. 5. Isodose rate curves at H + 1 for the Gerboise Bleuetest (in Gy/h).

0 500 1.000 m

10

3

1

0.30.1

100

10

0 200100

30

N

FIG. 6. Isodose rate curves at H + 1 for the GerboiseBlanche test (in Gy/h).

N

0 200 400 600 800 m

1

0.1

0.01

0.01

0.001

0.0001

FIG. 7. Isodose rate curves at H + 1 for the Gerboise Rougetest (in Gy/h).

N

0.05

0.1

0.3

15

0 200 400 600 m

0.01

FIG. 8. Isodose rate curves at H + 1 for the Gerboise Vertetest (in Gy/h).

9

Z1 Z5 Z2

NNN

N

GERBOISE BLEUE GERBOISE ROUGE GERBOISE VERTE

GERBOISE BLANCHE

0.5 km

1 km2

0.05 km

0.015 km2

0.006 km2

0.002 km2

Z0

0.5 km0.5 km

0.56 km2

0.22 km2

0.15 km2 0.08 km20.15 km2

from 0.05 to 0.5 µGy/h (from 0.02 to 0.2 MBq/m2)from 0.5 to 1.5 µGy/h (from 0.2 to 0.6 MBq/m2)from 1.5 to 5 µGy/h (from 0.6 to 2 MBq/m2) from 5 to 15 µGy/h (from 2 to 6 MBq/m2)

FIG. 9. Evaluation of dose rates and surface activity of 137Cs in soil in 1999, and surface areas of fallout zones.

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Consequently a large amount of the residual activityremains in material buried under several metres ofsand.

At present the highest dose rates should be ofthe order of a few micrograys per hour in theimmediate vicinity of the ground zero points of theGerboise Bleue and Gerboise Blanche tests, and afew tenths of a microgray per hour for the other twoGerboise tests (marginally higher than the naturalbackground).

The residual activity remaining after partialdecay of the long lived fission products (90Sr and155Eu) has been assessed from their relative fissionyields, assuming there has been no fractionation ofthese radionuclides with respect to 137Cs during thedeposition process.2 The activity ratios would thencurrently be:

90Sr/137Cs ª 0.31155Eu/137Cs ª 0.003

The activity of activation products depends onthe nature of the test device, the supportcomponents (tower, etc.) and the environment (soiltype, etc.) and is therefore more difficult to predict.If we use the same hypotheses to estimate theproduction of 55Fe and 60Co as were used by theIAEA to determine the radiological situation atMururoa and Fangataufa [1], i.e.:

— 1.5 × 1013 Bq of 55Fe produced per kilotonne,and

— 55Fe/60Co activity ratio between 6 (under-ground tests) and 10 (tower tests),

then the residual activity of 60Co (5.27 year half-life)after 38 years of decay would be between 1 × 104

MBq (test on tower) and 2 × 104 MBq (undergroundtest) per kilotonne. The theoretical average ratio of60Co/137Cs activity should at present lie between0.003 and 0.006.

On the basis of their half-lives, three otheractivation products could still be present: 133Ba (10.5years), 152Eu (13.53 years) and 154Eu (8.59 years).The average activities should be of the same orderof magnitude as that of 60Co and undoubtedlyshould not exceed a few per cent of that of 137Cs.

The related data for the activity of 239+240Puwere estimated from the mass of fissile materialused and the radiochemical measurements madeafter the tests.

An evaluation of the mean residual activityin 1999, normalized to that of 137Cs, in the vicinityof the Gerboise ground zero points is given inTable 2. This evaluation must be considered withcaution, because it does not take into account thephysicochemical characteristics or the mode ofproduction of the various radionuclides, which canlead to substantial distortion (fractionation)between the ratios of products formed by the testand the ratios of products effectively deposited onthe ground.

Based on Table 2, Table 3 shows an evaluationof the mean residual surface activity in 1999.

2.2.2. Underground tests

The underground tests were carried out intunnels dug into the granite massif of Taourirt TanAfella. This area and its immediate surroundingswere virtually uninhabited at the time of the tests.

2 The analytical results for the samples collected onthe site during the IAEA mission of November 1999 showa significant fractionation of the products (see Section4.4). The actual ratios standardized to the 137Cs are signif-icantly higher than indicated by this estimation, showingrelatively low 137Cs deposition, in good agreement withthe known volatile behaviour of caesium.

TABLE 2. MEAN RESIDUAL ACTIVITY IN 1999 IN THE VICINITY OF THE GERBOISE GROUND ZERO POINTS IN THE ABSENCE OF FRACTIONATION (NORMALIZED TO THAT OF 137Cs)

Radionuclide Bleue Blanche Rouge Verte

90Sr 0.3 0.3 0.3 0.3137Cs 1 1 1 1155Eu 0.003 0.003 0.003 0.00360Co ~0.005 ~0.005 ~0.005 ~0.005133Ba £0.01 £0.01 £0.01 £0.01152Eu £0.01 £0.01 £0.01 £0.01239+240Pu 0.1 1 2 5

11

The rock overlying the firing points was sufficientlythick for test containment (several hundred metreson the average). The system was designed so thatthe radioactive products would be confined withinthe mountain at the ground zero point, in rock thatbecame molten at the moment of firing.Containment was normally ensured by the design ofthe tunnel, which would be closed by the shockwave before any radioactive material could escape.

Table 4 lists the tests that were performed. Thetotal energy released by the 13 tests was about270 kt.

The estimated gross residual activities of themain radionuclides in the massif after 35 years ofdecay are given in Table 5.

Table 6 gives an estimate of the currentspecific activities of the lava buried in the mountain(total mass of about 3.5 × 105 t).

Of the 13 tests performed in the Taourirt TanAfella massif:

(a) Nine tests (Agate, Emeraude, Opale, Topaze,Turquoise, Saphir, Corindon, Tourmaline andGrenat) were fully contained.

TABLE 3. MEAN RESIDUAL SURFACE ACTIVITY (MBq/m2) IN 1999 IN THE VICINITY OF THEGERBOISE GROUND ZERO POINTS IN THE ABSENCE OF FRACTIONATION

Bleue Blanche Rouge Verte

~1 km2~1 km2

~0.2 km2~0.1 km2

90Sr 0.01–0.6 0.01–0.9 0.01–0.1 0.01–0.1137Cs 0.02–2 0.02–3 0.02–0.2 0.02–0.2155Eu £0.01 £0.01 £0.001 £0.00160Co £0.01 £0.02 £0.001 £0.001133Ba £0.02 £0.03 £0.002 £0.002152Eu £0.02 £0.03 £0.002 £0.002239+240Pu 0.001–0.2 0.02–4 0.04–4 0.09–9

TABLE 4. UNDERGROUND NUCLEAR TESTS PERFORMED IN THE TAOURIRT TAN AFELLAMASSIF

Namea Date Type Yield, W (kt)

Agate 1961-11-07 Tunnel W < 10

Béryl 1962-05-01 Tunnel 10 < W < 40

Emeraude (Georgette) 1963-03-18 Tunnel 10 < W < 40

Améthyste 1963-03-30 Tunnel W < 10

Rubis 1963-10-20 Tunnel 40 < W < 80

Opale (Michèle) 1964-02-14 Tunnel W < 10

Topaze 1964-06-15 Tunnel W < 10

Turquoise 1964-11-28 Tunnel W < 10

Saphir (Monique) 1965-02-27 Tunnel W > 80

Jade 1965-05-30 Tunnel W < 10

Corindon 1965-10-01 Tunnel W < 10

Tourmaline 1965-12-01 Tunnel 10 < W < 40

Grenat (Carmen) 1966-02-16 Tunnel 10 < W < 40

a Partial information relating to the phenomenology of some tests was declassified within the APEX programme (Applicationpacifique des expérimentations nucléaires — Peaceful Nuclear Test Programme); the corresponding APEX denominationsare given in italics.

12

(b) Two tests (Rubis and Jade) were not fullycontained in their respective galleries andgave rise to characteristic discharges (iodinesand gases) from the tunnel openings. In thecase of Jade, the activity detected outside thevicinity of the tunnel entrance was low. OnlyRubis led to measurements of significantactivity outside the test area at the time of thetest. In view of the short half-lives of theradionuclides involved, no residual activityshould be detectable at these locations now.

(c) Two tests (Béryl and Améthyste) were onlypartially contained and significant releases ofradioactive products took place.

With the exception of the Béryl andAméthyste test areas, which are examined in thenext two sections, the other areas of the TaourirtTan Afella massif (used for the underground tests)should not display any significant radiologicalresidues outside the galleries.

2.2.2.1. Béryl test

The Béryl test was carried out on 1 May 1962,on the north-east side of Taourirt Tan Afella, intunnel E2 North. To contain the test, a spiral shapedtunnel opened into the firing chamber (Fig. 10). The

spiral was designed to be closed off by the shockwave before the lava could reach the entrance of thetunnel. Blocking of the main tunnel did not takeplace as planned (probably because of a physicsexperiment situated in a tunnel parallel to the maintunnel which may have short-circuited the spiral).

A fraction of the test product’s activity, of theorder of 5–10%, escaped as lava, aerosols andgaseous products. The geometrical characteristics ofthe three lava streams (Figs 11–13) are given inTable 7.

To evaluate the residual activity outside thetunnel, the following conservative hypotheses wereadopted:

— Discharge of 5–10% of the products formed,distributed in 10 000 t of contaminated soil(lava and scoria);

— No fractionation of the fission products3.

TABLE 5. GROSS RESIDUAL ACTIVITY (TBq) IN 1999 FROM THE UNDERGROUND TESTS

Radionuclide 239+240Pu 238Pu 90Sr 137Cs 155Eu 60Co

Remaining activity 240 15 250 800 1.5 <8

TABLE 6. MEAN RESIDUAL SPECIFIC ACTIVITY IN 1999 OF THE UNDERGROUND TEST LAVA(MBq/kg)

Radionuclide 239+240Pu 238Pu 90Sr 137Cs 155Eu 60Co

Concentration 0.7 0.045 0.72 2.3 0.004 <0.02

3 In practice, significant fractionation could beobserved between the various radionuclides, especiallyfor 137Cs.

TABLE 7. GEOMETRICAL CHARACTERISTICS OF THE THREE LAVA STREAMS

Location of the lava stream Volume (m3) Length (m) Mean thickness (m)

On the side of Tan Afella 70 20 0.1

On the road below the bank 70 44 0.4

On the hill opposite the entrance 600 150 0.2

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Estimates of activities and mean residualconcentrations after 35 years of decay are shown inTable 8.

In the analyses performed between 1962 and1965 on lava or scoria samples, the mean ratios for

239+240Pu/137Cs and 90Sr/137CS were of the order of 0.1and 0.32, respectively, indicating that the concentra-tions of 239+240Pu could reach 0.37 MBq/kg.

The most recent measurements available tothe mission team date back to 1965, about threeyears after the test. At that time, the 1 m dose rateswere between 2 and 10 mGy/h in an area coveringabout 0.03 km2, and between 0.05 and 2 mGy/h in anarea covering about 0.15 km2. The present-dayestimated dose rates in the area contaminated bythis test are shown in Fig. 14.

FIG. 10. Arrangement of a tunnel used for weapon testing.

FIG. 11. General view (photograph taken in 1962) in anortherly direction of the area contaminated by the Béryltest. On the left is bank E2 at the foot of the eastern slopeof the Taourirt Tan Afella massif. On the right is the south-western slope of the hill opposite the bank.

FIG. 12. Photograph taken in 1962 of the eastern slopeof the Taourirt Tan Afella massif at the end of bank E2 andthe lava stream caused by the Béryl test.

FIG. 13. Photograph taken in 1962 of the lava flow alongthe southwestern side of the hill and the lava flow at the footof bank E2.

14

In the area displaying the highest dose rates,the contamination is fixed in the lava. Most of thearea with dose rates currently estimated at morethan 1 mGy/h is difficult to access owing to the veryhilly topography: the side of the Taourirt Tan Afella,the entrance to the tunnel blocked by rocks, thewest side of the hill facing the tunnel entrance (witha slope of about 40%), the thalweg (small valley)giving access to the bank, etc.

To prevent access, the area that was contami-nated by this test was entirely fenced off andappropriate warning signs that forbid entry wereaffixed to the fence.

2.2.2.2. Améthyste test

During the Améthyste test that wasperformed on 30 March 1963, on the eastern side ofTaourirt Tan Afella in the E3 tunnel, a smallquantity of molten rock and scoria escaped and wasdeposited near the entrance of the tunnel and in theimmediate vicinity.

In 1965, the residual dose rates at 1 m abovethe surface could have exceeded 50 mGy/h in anarea covering about 0.03 km2. The area contami-nated by this test that is estimated to have a present-day dose rate of >1 mGy/h is shown in Fig. 15.

2.2.3. Experiments with plutonium pellets

Subsidiary experiments were designed tomeasure the velocity of a shock wave in a pellet ofplutonium. They were carried out near the areaused for the Gerboise Rouge test.

A total of 35 experiments in three series wereperformed at Reggane in April–May 1961, April1962 and March–May 1963 (T3 and T4 sites, Fig. 2).Each experiment involved a plutonium pelletweighing about 20 g.

from 1 to 30 mGy/hfrom 30 to 300 mGy/h

Colour scale

0 100 200 m

FIG. 14. Evaluation of dose rates in 1999 in the area contaminated by the Béryl test (extrapolated from measurementsperformed in 1965).

TABLE 8. ESTIMATION OF CURRENT MEANRESIDUAL ACTIVITY IN THE AREA CON-TAMINATED BY THE BÉRYL TEST

RadionuclideActivity (TBq)

Concentration (MBq/kg)

137Cs 5–10 0.5–190Sr 1–3 0.1–0.3239+240Pu 1–2 0.1–0.2238Pu 0.1–0.2 0.01–0.02

15

The experiments were carried out in pits tolimit dispersal. The majority of the plutoniumremained in the pits. Low residual activity might stillbe detected near the test pits.

2.2.4. Pollen experiments

The Pollen experiments were designed tosimulate an accident involving plutonium and tomeasure its consequences, including the degree ofcontamination that might arise in the vicinity. Themethod used consisted of measuring quantities ofplutonium aerosols (spiked with 177Lu) generatedby pyrotechnic dispersal. The experiments werecarried out in a desert-bound region of AdrarTikertine (Fig. 3), some thirty kilometres south-westof Taourirt Tan Afella.

Five experiments involving 20 to 200 g ofplutonium were carried out between May 1964 andMarch 1966, using the same firing area. Theexperiments were performed when winds wereblowing across the sector planned for collection ofthe fallout.

For the five experiments, the plutoniumdeposit measured in the axis of the plume couldhave reached 3 × 103 kBq/m2 up to 50 m fromthe ground zero point, and could then havefallen to below 40 kBq/m2 beyond 1 km.After each experiment, the most contaminatedarea was covered with asphalt to limitresuspension.

On the basis of the experiments performed atthis site, low residual activity might still be detectednear the ground zero point.

from 1 to 30 µGy/h

FIG. 15. Evaluation of dose rates in 1999 in the area contaminated by the Améthyste test (extrapolated from measurementsperformed in 1965).

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3. IAEA MISSION

The Government of Algeria requested theIAEA to assess the levels of residual radioactivematerial at the sites where nuclear activities wereconducted, to evaluate the potential radiologicalimpact, and to advise on whether furthermonitoring of test sites was required and to whatextent.

Accordingly, a fact finding field mission wassent to Algeria to make a preliminary assessment ofthe present radiological situation of the Regganeand In Ekker former nuclear test sites. Theobjective of this mission was to visit, jointly with theAlgerian counterparts, the former French nucleartest sites, to perform in situ measurements andmake a preliminary assessment of the current radio-logical conditions. A decision on the necessity toconduct more elaborate studies in the future wouldbe possible on the basis of the findings of thismission.

In the absence of detailed information on thenuclear test programme, the contribution of theFrench expert on the team in providing briefingsconcerning each site was invaluable. Thisinformation is documented in Section 2 of thisreport.

The Algerian project counterpart personneljoined the IAEA mission and made all thenecessary (logistical and other) arrangements forthe implementation of the mission. The localauthorities in Adrar (Reggane) and Tamanrasset(In Ekker) provided local logistical support, such asground transportation and security arrangements.Internal travel by air (Algiers–Adrar–Tamanrasset–Algiers) was provided by the AlgerianGovernment. This mission was sponsored by theIAEA Technical Cooperation Project ALG/9/014.

3.1. MISSION TEAM

The IAEA mission team was composed of thefollowing international experts in the areas of radio-logical monitoring, laboratory analysis, radiationdosimetry and radiation protection: AndrewMcEwan from New Zealand, Steven L. Simon fromthe United States of America, Jean-FrancoisSornein from France, Peter Stegnar from Sloveniaand Pier Roberto Danesi from the IAEA.

During the mission, the IAEA team wasaccompanied by the following national experts(Fig. 16) from the Algerian Commissariat à

l’énergie atomique (COMENA): Y. Touil,A. Noureddine, A. Gheddou, M. Benkrid,M.S. Hamlat, R. Affoune, M. Chikouche andN.E. Rais.

3.2. MISSION ITINERARY

Thursday, 18 November 1999

Arrival of IAEA mission expertsin Algiers.

Friday, 19 November 1999

Meeting with the Algerian team,departure for Adrar (the Regganetest site).

Saturday, 20 November 1999

Visit to the Reggane test site —four test locations where atmos-pheric (surface) tests were con-ducted. The team took externalexposure dose rate measurementsand air samples, and collectedsand and other environmentalsamples. A preliminary assess-ment of the radiological condi-tions was made.

Sunday, 21 November 1999

Continuation of work at theReggane test site. In addition,environmental samples werecollected in Reggane, and a pre-liminary assessment of the radio-logical situation was made.

Monday, 22 November 1999

Travel to Tamanrasset (the InEkker site).

FIG. 16. The mission team.

17

Tuesday, 23 November 1999

Visit to the Taourirt Tan Afella (InEkker) underground test site. Theteam took external exposure doserate measurements at the site con-taminated with lava (from theBéryl test), collected environmen-tal samples of lava, sand and vege-tation (inside and outside thefence), and collected watersamples from three wells in thisarea.

Wednesday, 24 November 1999

Visit to the Adrar Tikertine site(plutonium dispersion experi-ment). The team took dose ratemeasurements and air samples,and collected surface sand.

Thursday, 25 November 1999

Travel to Algiers, discussion withcounterpart personnel on resultsof the mission, final discussion ofthe mission.

Friday, 26 November 1999

Departure from Algiers.

18

4. SAMPLING AND MEASUREMENT PROGRAMME

4.1. INTRODUCTION

4.1.1. Reggane

On 20 November 1999, the sites GerboiseBleue and Gerboise Blanche were inspected for thepurpose of determining sampling locations. On21 November the sites Gerboise Rouge, GerboiseVerte, T3 and T4 were inspected for similarpurposes. At the site of each test, the ground zeropoint was identified by visual inspection and globalpositioning system (GPS) measurements. Then,moving along the major axis of the areas (circular orelongated) where some residual contamination wasexpected, dose rate measurements were taken atlocations about 100 to 200 m apart. Several doserate meters were used for the purpose of comparingand verifying measurement data. At each pointwhere the dose rate was measured, the geographicalcoordinates were recorded as determined by ahandheld GPS unit. Several samples of sand mixedwith black, fused sand (that had been solidified bythe heat of the explosion) were collected at selectedpoints. The measured dose rates were comparedwith those estimated by the French Commissariat àl’énergie atomique (CEA) from measurementsfollowing the conduct of the tests (see Section 2).Findings from these measurements are presented inSection 4.4.

4.1.2. In Ekker (Taourirt Tan Afella and Adrar Tikertine)

On 23 November 1999, the team inspected theTaourirt Tan Afella area and in particular the areaimmediately in front of the E2 tunnel (where apartially confined test occurred) and the adjacentarea. Full protective clothing was worn in the areain front of the E2 tunnel. Starting from the fencebuilt by the French authorities and moving in thedirection of the entrance of the E2 tunnel, radiationdose rates were measured at close intervals usingseveral dose rate meters, and the locations wererecorded using the GPS. Some lava and soil sampleswere collected at selected points. A few samples ofsand and vegetation were also collected along thepath of dry water streams running from the site inthe direction of the fence, on the assumption that ifsome contamination had been transported byrainwater, it would probably have accumulated in

these locations. A water sample was also collectedfrom a water well located at a distance of a fewkilometres from the fence. The entrance to the E3gallery was also inspected and external dose ratemeasurements were taken in the vicinity.

On 24 November 1999, the team inspected theAdrar Tikertine area. Masks were worn during thissurvey as a precaution against breathing fineparticles suspended from the ground by high winds.The detonation site of the plutonium dispersionexperiment (also known as the Pollen test) wasidentified with some difficulty because little in theway of visual clues remains today. Traces of asphaltwere still visible in the proximity of the detonationsite and also at distances of several hundred metres.Moving from the detonation site along the directionof the 213º axis, the team recorded the dose rates atregular intervals as well as the correspondinggeographical coordinates obtained from the GPSfor a few kilometres. Samples of sand were alsocollected at different depths. By using a portableNaI based spectrometry instrument, a few gammaspectra were recorded at this site, thoughmonitoring equipment especially designed formonitoring the low energy gamma emissions fromplutonium and americium was not available.

4.2. FIELD MEASUREMENTS

The absorbed dose rates in air at 1 m aboveground were measured with field survey meters,such as GM counters (FAG and ESM models) andNaI scintillation detectors (GR 320 Exploraniumand GR 130 Minispec models). The dose rates weretaken at 76 different locations at the Reggane andIn Ekker test sites with five different survey metersand three scintillation detectors, with an overalldifference between instrument readings of about30%. The differences between instruments were notconsidered important for radiation protection orassessment purposes.

4.3. FIELD SAMPLING

The field sampling, although an importantaspect of the fact finding mission, was not intendedto be as comprehensive as a full scale radiologicalmonitoring programme might generally be. In thiscase, only a limited number of samples wereobtained to provide preliminary data on the

19

radiological conditions, on the basis of whichrecommendations for further work could be made.The environmental media that normally includemost of the local inventory of radioactive residuesare soil, water and vegetation. In general, therelative frequency of sampling for each mediumwithin the context of a well planned survey dependsin part upon the availability of the samples and theirimportance to the assessment. In the case of theformer French nuclear test sites in Algeria, the soilis low in organic material and coarse sand particlesthat are readily accessible for sampling. Withrespect to vegetation, none was available at theReggane test site as the area is entirely a desert.Similarly, there were no water wells available at thatsite. The In Ekker region, though also desert-like,has sparse vegetation surrounding the Taourirt TanAfella mountain and in some stream beds which aredry most of the year. These stream beds originate inthe sites. In this area, there are a few scattered andremote water wells which local travellersoccasionally use.

4.3.1. Soil

Soil was sampled primarily in the interest ofevaluating the resuspendable fraction that mightexpose intermittent visitors and travellers as aconsequence of high winds leading to dustyatmospheric conditions. For that purpose, soil wassampled at both the Reggane and In Ekkerlocations by collecting the top layer, to a depth oftypically between 2 and 4 mm, over an area of about0.5–1.0 m2 (see Fig. 17). In addition, fused sandremaining from the above ground tests at theReggane site was also collected. Samples werebagged for transport and marked with identifi-

cation, and exposure rate measurements were takenas corroborative information.

4.3.2. Water

Water from three different wells in the areanear In Ekker on the route towards Adrar Tikertinewas sampled by collecting water directly from thebucket used by travellers, which is dropped into adeep hole and drawn out on a rope.

4.3.3. Vegetation

Because of the scarcity of vegetation, only twoplant samples were collected, both on the slopes ofthe Taourirt Tan Afella mountain beneath the E2tunnel where the large release occurred. The planttypes collected are known to be used by camels asfood, though the particular plants sampled would beunavailable to them as they were located within asecurity fence. The plant types sampled were Aervapersica (Tomaberzist) and Atriplex halimus (araña).

4.4. RESULTS OF SAMPLING AND MEASUREMENTS

This section summarizes the field measure-ments and laboratory analyses of the samples thatwere collected during the mission. A complete set ofmeasurement data is provided in Appendix I.

4.4.1. Field measurements

4.4.1.1. Reggane

At the site of the Gerboise Bleue test, doserate measurements were made by the IAEA teamfrom the ground zero point along two transectionsroughly perpendicular to one another. Onetransection was in the northwesterly direction, andthe measured dose rates varied from 2.7 mSv/h nearthe ground zero point to about 0.1 mSv/h(background) at a distance of about 500 m fromground zero. The other transection was in the north-easterly direction, and the dose rates varied fromaround 1.5 mSv/h near the ground zero point toabout 0.1 mSv/h (background) at a distance of 700 mfrom ground zero. Figure 18 shows the locations andvalues of the measurements relative to the originalisodose contours produced by the French author-ities. Figure 19 shows a three dimensional plot of thevalues, which can be seen to decrease approxi-mately exponentially with increasing distance fromFIG. 17. Sand sampling at the Adrar Tikertine site.

20

26˚ 19.4' N

26˚ 19.2' N

26˚ 19.0' N

26˚ 18.8' N

26˚ 18.6' N

26˚ 18.4' N

26˚ 18.0' N

26˚ 18.2' N

00˚0 4.0' W 00˚ 03.8' W 00˚0 3.6' W 00˚0 3.4' W 00˚ 03.2' W 00˚0 3.0' W 00˚0 2.8' W

Point Alpha [19]

[18] 0.11

[17] 0.12

[16] 0.17

[15] 0.30

[14] 0.66

[13] 0.85[12] 2.25

[11] 2.701.50 [10]

1.00 [9]

1.04 [8]0.53 [7]

0.44 [6]0.38 [5]

0.20 [4]

0.13 [3]0.10 [2]

Sphinx [1]

30

10

1

0.1

0.01

0 200 400 600 800 m

Zero Point

GERBOISE BLEUE TEST

Isodose rate curves at H+1 (in Gy/h)

Station numbers in square brackets Measured dose rates in µSv/h

FIG. 18. Dose rate data obtained during the IAEA field mission to the Reggane test site near ground zero of the Gerboise Bleuetest, compared with H + 1 values (see also Fig. 5).

ZeroPoint

AlphaPoint

ME

AS

UR

ED

DO

SE

RA

TE

S (

µS

v/h)

Sphinx

North-east to south-west survey South-east to north-west survey

GERBOISE BLEUE TEST

FIG. 19. Dose rate data obtained during the IAEA field mission to the Reggane test site near ground zero of the Gerboise Bleuetest, showing a rapid decrease to background levels at distances of about 500 m.

21

ground zero and which reach close to backgroundlevels at 500 to 600 m from the ground zero point.

At the site of the Gerboise Blanche test, doserate measurements were made by the IAEA teamalong a north-east to south-west transection thatcrossed near the ground zero point. Dose ratesvaried from about 0.15 mSv/h at 300 m (south-westerly direction) to about 0.35 mSv/h near theground zero point and decreased to about0.27 mSv/h at a distance of about 100 m (north-easterly direction). Figure 20 shows these dataplotted over the original isodose contoursdeveloped by the French authorities following thetest.

At the site of the Gerboise Rouge test, theIAEA team performed dose rate measurementsalong two perpendicular transections, one runningnorth to south and a second running east to west.Dose rates varied from about 0.06 mSv/h at 400 m

(easterly direction) to about 0.2–0.35 mSv/h nearthe ground zero point, decreased to about0.04 mSv/h at a distance of about 400 m (westerlydirection). The measurements along the north–south transection varied similarly. Figure 21 showsthe collected data overlaid on the original isodosecontours developed by the French authorities,while Fig. 22 shows a three dimensional represen-tation of these data.

At the site of the Gerboise Verte test, theIAEA team made dose rate measurements along asingle transection running from north-east to south-west and passing near the ground zero point; a fewadditional measurements were made in the nearvicinity. Dose rates varied from about 0.01 mSv/h atabout 400 m (southwesterly direction) to about0.2 mSv/h near the ground zero point and decreasedto about 0.14 mSv/h at a distance of about 200 m(northeasterly direction). Figure 23 shows these

26˚09.9' N

26˚09.8' N

26˚09.7' N

26˚09.6' N00˚06.4' W 00˚ 06.3' W 00˚06.2' W 00˚06.1' W

0.27 [4]

0.50 [1]

0.35 [2] 0.39 [3]

0.90 [5]

0.50 [6]

0.43 [7]

0.26 [8]

0.15 [9]

0.49 [10]

Zero Point100

10

3

0.1

30

3

1

0.3

1

0 100 200 m

GERBOISE BLANCHE TEST

Station numbers in square brackets Measured dose rates in µSv/h

Isodose rate curves at H+1 (in Gy/h)

FIG. 20. Dose rate data obtained during the IAEA field mission to the Reggane test site near ground zero of the GerboiseBlanche test, compared with H + 1 values (see also Fig. 6).

22

0.1

0.01

1

26˚ 21.5' N

26˚ 21.3' N

26˚ 21.1' N

26˚ 20.9' N00˚ 07.8' W 00˚0 7.6' W 00˚ 07.4' W 00˚0 7.2' W

0.14 [9]

0.15 [8]

0.18 [7]

0.24 [6]

0.25 [2]

0.23 [3]

0.17 [4]

0.14 [5]

0.26 [1]

0.04 [6]

0.19 [7]

0.05 [5]

0.06 [4] 0.15 [3] 0.34 [2] 0.20 [1]0.08 [8] 0.06 [9] EW survey ( )

NSsurvey

( )

Zero Point

0 100 200 300 400 m

GERBOISE ROUGE TEST

Isodose rate curves at H+1(in Gy/h) Station numbers in square brackets Measured dose rates in µSv/h

FIG. 21. Dose rate data obtained during the IAEA field mission to the Reggane test site near ground zero of the Gerboise Rougetest, compared with H + 1 values (see also Fig. 7).

DISTANCES FROM ZERO POINT (metres)DISTANCES FROM ZERO POINT (m

etres)

ME

AS

UR

ED

DO

SE

RA

TE

S (µ

Sv/

h)

ZeroPoint

East-West survey

North-South survey

GERBOISE ROUGE TEST

East-west survey North-south survey

FIG. 22. Dose rate data obtained during the IAEA field mission to the Reggane test site near ground zero of the Gerboise Rougetest, showing a rapid decrease to background at distances of about 400 m.

23

data plotted over the original isodose contoursdeveloped by the French authorities following thetest.

4.4.1.2. In Ekker — Taourirt Tan Afella

The dose rates in the vicinity of the TaourirtTan Afella mountain varied widely, primarily as afunction of proximity to the solidified lava in frontof the E2 tunnel. Outside the original fence built bythe French authorities, the most distant point ofwhich is about 800 m from the E2 tunnel opening,the dose rates were about 0.1–0.2 mSv/h abovebackground. Inside the fence, and progressing upthe sloped hillside towards the E2 tunnel, dose ratesrose two- to fourfold, to as high as 0.45 mSv/h and0.7 mSv/h at some locations. Directly in front of theE2 tunnel opening and on top of the solidified lava,dose rates were measured at up to 200 mSv/h.

Figure 24 shows a topographical map of the TaourirtTan Afella mountain (Béryl test zone), giving theisodose rates extrapolated to 1999 and the doserates measured by the IAEA team.

The maximum external exposure ratemeasured near the entrance to the E3 gallery wasabout 0.32 mSv/h, and the exposure rates wereelevated above background (about 0.1 mSv/h) out toa distance of a few hundred metres.

4.4.1.3. In Ekker — Adrar Tikertine

The dose rates in the vicinity of AdrarTikertine were at background levels. The collectedgamma spectra nominally showed the presence of241Am (a product of ingrowth from 241Pu), indicatingthat 239Pu should also be present, though thesespectra could not be evaluated quantitatively, norwas the detector of a type that optimized the

26˚19.5' N

26˚19.4' N

26˚19.3' N

26˚19.2' N

26˚19.1' N00˚04.6' W 00˚04.5' W 00˚ 04.4' W 00˚ 04.3' W 00˚ 04.2' W

Zero Point

0.14 [3]

0.18 [2]

0.09 [1]0.1

0.01

1

5

0.3

0.05

0 100 200 300 400 m

[4]

Isodose rate curves at H+1 (in Gy/h)

Station numbers in square brackets Measured dose rates in µSv/h

GERBOISE VERTE TEST

FIG. 23. Dose rate data obtained during the IAEA field mission to the Reggane test site near ground zero of the Gerboise Vertetest, compared with H + 1 values (see also Fig. 8).

24

detection efficiency of the low energy (60 keV)gamma emissions. Figure 25 shows the surveylocations.

4.4.2. Laboratory measurements

The samples collected and the coordinatesof the collection points are reported in Tables 11–14 in Appendix I. Selected samples were analysedby high resolution gamma spectrometry and byalpha and beta spectrometry after radiochemicalseparations at the IAEA’s Laboratories in Seiber-sdorf. The concentrations of the following radio-nuclides have been determined: 133Ba, 60Co, 137Cs,152Eu, 154Eu, 155Eu, 40K, 228Ra, 228Th (gammaemitters); 90Sr (beta emitter); and 238Pu, 239+240Pu(alpha emitters). Americium-241 and 239Pu werealso determined by high resolution gamma

spectrometry. The samples analysed consisted ofsand, black fragments of fused sand, lava andwater from a water well. In some sand samples,the fraction composed of particles with diametersof <50 mm was isolated by sieving, and theconcentration of the gamma emitting radio-nuclides was measured by high resolution gammaspectrometry. One sample consisting of blackfused sand (from the Gerboise Blanche test atReggane) and one sample consisting of lava(collected in front of the E2 tunnel in TaourirtTan Afella) were also subjected to a preliminaryleaching experiment. The vegetation samples, twowell water samples and air filters remain withCOMENA in Algeria and have not yet beenanalysed.

The results of all the analyses performedand a description of the procedures used in the

24˚04.1'

24˚04.0'

24˚03.9'

24˚03.8'

24˚03.7'

24˚03.6'

24˚03.5'05˚03.2' 05˚03.3' 05˚03.4' 05˚03.5' 05˚03.6' 05˚03.7' 05˚03.8' 05˚03.9' 05˚04.0' 05˚04.1' 05˚04.2'

200

4.0

30

0.24

0.69

0.320.27

0.24

0.20-0.26

0.19-0.25

0.12

0.08

1.0

0.28

0.45

0.30

0.12

0 400 m200

24˚04.2'

original French fence

1-30µGy/h

30-300µGy/h NORTH

BERYL TEST ZONE

Measured dose rates in µSv/h

EAST

Isodose rate curves in 1999 (pre-survey evaluation)

FIG. 24. Topographic map of the Béryl test zone (Taourirt Tan Afella mountain), showing the measured dose rate values andsampling locations.

25

laboratory measurements are given in detail inAppendix I.

4.4.3. Major conclusions based on the laboratory measurements

The number of samples collected and analysedis somewhat small when viewed against the size ofthe sites visited during the field mission. This lowratio of number of samples to total area, particularlyfor Adrar Tikertine, restricts the general validity ofconclusions that can be drawn by extrapolating thelaboratory measurements to the entire areaspotentially affected by the nuclear tests. Keepingthis limitation in mind, the following conclusionscan be drawn.

4.4.3.1. Samples from Reggane

All sites in Reggane are contaminated.Gerboise Blanche and Gerboise Bleue are locallyhighly contaminated, with most of the contami-nation residing in the black, vitreous and porous

material (sand melted at the time of the explosionand then solidified, see Fig. 26). The unvitrified sandis much less active (100–1000 times less). A typicalsample, such as ALG-3 (sand with many blackfragments of fused sand), had the following activityconcentrations:

23˚56.2' N

23˚55.8' N

23˚55.4' N

23˚55.0' N04˚4 3.6' E 04˚44.0' E 04˚44.8' E04˚44.4' E

ADRARTIKERTINE

0.06 [1]

0.60 [2]

0.27 [3]

[4]

ALG-22/23

ALG-24/25

Zero Point (estimated)

0 400 mhills

213˚

Station numbers in square brackets Measured dose rates in µSv/h

POLLEN EXPERIMENTS

FIG. 25. Dose rate data obtained during the IAEA field mission to the Pollen experiment test area.

FIG. 26. Black fragments of fused sand.

26

239+240Pu = 1.2 × 106 Bq/kg;137Cs = 2.9 × 104 Bq/kg;90Sr = 1.8 × 105 Bq/kg.

The activity concentrations of the anthropo-genic radionuclides in the sand fraction containingparticles with a diameter of <50 mm were ingeneral equal to or less than the level of detection(a few tens of becquerels per kilogram). The onlymeasurable radionuclides were 137Cs and thenatural isotopes 40K, 228Ra and 228Th. The activityconcentration of 137Cs was about 200 Bq/kg. Theactivity concentrations of 40K, 228Ra and 228Th wereabout 300 Bq/kg. These data indicate that theactivity concentrations of the radionuclidesgenerated by the nuclear tests in the sand fractionthat can be transported some distance (<50 mm)and that is respirable (<10 mm) should benegligible.

One sample consisting of 5 g of black fusedsand (from sample ALG-3 of the Gerboise Blanchesite at Reggane) was also leached by water at 40oC.After washing of the sample with distilled water toremove particles and dust, the activity concentrationsof 137Cs, 90Sr, 241Am and 239+240Pu in the leachate weremeasured after a leaching period of 30 days. Theradionuclides in the leachate were always below or atthe minimum detectable activity, i.e. less thanapproximately 1 Bq/L for 137Cs, less than approxi-mately 3 × 10–2 Bq/L for 90Sr, less than approxi-mately 1 × 10–3 Bq/L for 241Am and less thanapproximately 2 × 10–2 Bq/L for 239+240Pu. The lowradionuclide activity in the leachates generallyindicates that the radionuclides are immobilized inthe matrix of the vitreous fused sand. However,further and more representative experiments shouldbe conducted before confirming this conclusion.

4.4.3.2. Samples from In Ekker — Taourirt Tan Afella

The Taourirt Tan Afella location is whereseveral tunnel tests were conducted. The onlylocation from which samples were taken was thearea in front of the E2 tunnel where the partiallyconfined test occurred (with ejection of radioactivelava) and its proximity. The activity concentrationsof the more volatile radionuclides (caesium andstrontium) were greater in the lava than in thevitrified sand at the atmospheric test site, thoughthe concentration of plutonium was somewhat less.Activity concentrations in a typical lava sample (e.g.ALG-11) were:

239+240Pu = 4.2 × 104 Bq/kg;137Cs = 2.1 × 106 Bq/kg;90Sr = 1.1 × 106 Bq/kg.

One sample (ALG-8, consisting of 148 g ofejected radioactive lava taken from the area in frontof the E2 tunnel) was also leached following theprocedure mentioned previously. Also in this case,30 days of leaching resulted in concentrations of theradionuclides in the leachate below or at theminimum detectable activity.

The activity in the water taken from a welllocated about 6 km away from the E2 tunnel(sample ALG-21) was negligible, i.e.:

137Cs < level of detection (7.5 × 10–2 Bq/kg);90Sr < level of detection (2 × 10–2 Bq/kg).

The soil and sand in the dry stream bedscoming from the radioactive lava (ALG-18) had thefollowing activity concentrations:

239+240Pu = 50 Bq/kg;137Cs = 3.5 × 103 Bq/kg;90Sr = 1.2 × 104 Bq/kg.

4.4.3.3. Samples from In Ekker — Adrar Tikertine

The activity concentrations of 239+240Pu, 137Csand 90Sr in the coarse sand samples from AdrarTikertine were low. They fell in the range between 2and 15 Bq/kg, i.e. at the lower level of detection.The activity concentrations of plutonium in the sandfraction containing particles with a diameter of<50 mm were also equal to or less than the level ofdetection. The activity concentrations of 137Cs weresomewhat higher (about 23–28 Bq/kg) but stillrelatively close to the level of detection (about 12–23 Bq/kg); however, sieving was conducted on onlythree sand samples. This limited analysis gave noindication that significant quantities of 239+240Pu (orother anthropogenic radionuclides) released duringthe Pollen tests should be present in the sandfraction (<50 mm) and respirable. The Pollenexperiments would have been expected to dispersesome active particles (‘hot particles’) in the area,with the larger and heavier ones settling closest tothe site of dispersion in the area of the bitumenoverlay. Small particles in the respirable range haveprobably been widely dispersed in the interveningyears by the wind.

27

5. ESTIMATES OF PRESENT AND FUTURE DOSES TO PERSONS ARISING FROM RESIDUAL RADIOACTIVE MATERIAL AT THE SITES

5.1. GENERAL METHODOLOGY FOR CALCULATING DOSES

Generally, people may receive radiation dosesin several ways. Radionuclides emitting penetratingradiations, most commonly gamma radiation, cangive rise to a radiation dose even while they remainoutside the body (external dose). However, radio-nuclides in the air, in foods or on the ground mayalso be taken into the body by inhalation oringestion, or through cuts and wounds. Once radio-nuclides are within the body, emitted radiation isabsorbed by the cells of organs where the radio-nuclides are stored and those of neighboring organs,resulting in a dose (internal dose).

Assessing possible and likely future doses is athree stage process. The first stage is to gatherinformation about the environment, specifically theconcentrations of radionuclides in environmentalmaterials. For external doses, either the concentra-tions in soil or water or direct dose rate measure-ments in air are needed. For internal doses, it isnecessary to know the concentrations in foods oraerosols that may be taken into the body. Environ-mental conditions at the nuclear test sites have beendiscussed in the previous sections of this report. Thesecond stage of the process is to combine concentra-tions with exposure scenarios, including lifestylefactors and dietary information, to obtain the totallikely intake of activity. For external doses,information on the amount of time spent indifferent radiation fields is needed, while forinternal exposures, information on the amount offood eaten or air breathed is required. The finalstage is to use standard coefficients which eitherrelate concentrations in soil to external dose rates,or which convert a unit of intake into internal dose.These coefficients are estimated using mathematicalmodels of radionuclide behaviour and radiationabsorption in the body. Internationally agreedvalues of the committed effective dose per unitactivity intake for a large number of radionuclideshave been derived by the International Commissionon Radiological Protection (ICRP) [2] and arepublished in the International Basic SafetyStandards for Protection against Ionizing Radiation

and for the Safety of Radiation Sources (BSS) [3].These values have been used in the assessmentscarried out in the framework of the survey of thetest sites in Reggane and In Ekker.

5.2. SOURCES AND PATHWAYS OF EXPOSURE

Southern Algeria is in the Saharan zone. Theregion includes towns and villages with cultivationactivities, though there is no soil cultivation or plantproduction in the immediate area of the test sites. Itis an area of transit used by travellers, nomads andtransporters.

5.2.1. Atmospheric test site at Reggane

At the present time, as was also the case whenthe tests were run, the area of Reggane is an entirelyarid desert. For the purposes of dose estimation,and taking account of possible open access in futureyears, a scenario was assumed in which a personmight stay in the test area, for example throughovernight camping or other short term stay, for aperiod amounting to three days per year. Thisassumption excludes any future activity which couldimply greater occupation of the area by people. Ifthis assumption is not valid, a more detailed andcomprehensive radiological assessment of the sitesmay be required.

The principal exposure pathways fromresidual radionuclides from the atmospheric tests tooccasional transient visitors are:

— External exposure from radionuclides on theground;

— Inhalation of resuspended material;— Ingestion of soil adhering to hands and

deposited on foodstuffs, particularly in windyconditions.

The town of Reggane is the closest inhabitedlocation and is some 50 km distant from the nucleartest site. The doses that might arise to Regganeresidents through dust transport have also beenestimated.

28

5.2.2. Underground test site at In Ekker — Taourirt Tan Afella

The immediate area surrounding the TaourirtTan Afella mountain is nominally restricted, partic-ularly the area adjoining the entrance to the E2tunnel, which was fenced off in 1965, although inter-mittent grazing by animals such as camels, goats anddonkeys occurs throughout the region. Vegetation isvery sparse. Runoff water from the area seeps intounderground aquifers used for both stock waterand, in In Ekker some 5 km distant, for drinkingwater. There is evidence of scavenging of materialssuch as iron rails within the fence surrounding theE2 tunnel lava flow area. For the purposes of doseassessment, it is assumed that nomadic camel andgoat herders spend ten days per year in theimmediate vicinity of the site outside the originalfence, and that some persons and animalsoccasionally venture inside the fence in the vicinityof the E2 tunnel entrance.

The principal exposure pathways fromresidual radionuclides from the tests are:

— External radiation, particularly in the vicinityof ejected lava;

— Inhalation of dust;— Ingestion of dust;— Ingestion of water containing leached

material;— Ingestion of products (primarily milk and

meat) from livestock that intermittently grazein the area.

5.2.3. Adrar Tikertine experimentation site

The Pollen experiments caused dispersion ofplutonium in fine particulate form over a wide areain a southwesterly direction from the tower positionof the Adrar Tikertine experimentation site.Vegetation in the area is extremely sparse but isgrazed intermittently by stock herded by nomadicowners as at In Ekker. It is assumed that herdersmight be in the area for the equivalent of three daysper year. The original surface soil deposition of fineparticulates has been disturbed by both wind andwater transport of surface material. The arealdeposition of 241Am accompanying the plutonium isnot sufficiently high to give rise to a significantincrease in the terrestrial gamma ray background inthe area. The principal exposure pathways are

therefore inhalation and ingestion of contaminateddust.

Another potential route of exposure is incor-poration of radioactive particles in cuts and wounds.This may occur when wounds become contaminatedwith dust and soil, or if larger radioactive particlesare retained at wound sites. The significance of thispathway will depend upon several factors, particu-larly the prevalence and the activity and physicalsize distributions of active particles, their physico-chemical form, the length of occupancy of the area,the frequency of incidents leading to cuts andwounds, and the treatment applied to wounds.Conclusions drawn from other studies [4, 5] are thatexposure from contaminated wounds is likely to bevery small compared with that from ingestion, andthat the probability of long term incorporation of avery active particle is sufficiently low to not requirefurther consideration.

5.3. RADIATION DOSES DUE TO RESIDUES FROM NUCLEAR TESTING

The radiation doses that might arise to adultpersons present for short periods at the Regganedesert site, itinerant or resident in the In Ekkerregion, or itinerant in the Adrar Tikertine area,have been estimated from the radiological datapresented in Section 4. Figure 27 shows dose ratemeasurements being made. The details of the calcu-lations are given in Appendix II. Doses arising fromeach of the exposure pathways identified above, andfor all significantly contributing radionuclides, havebeen estimated.

FIG. 27. Dose rate measurements being made at theReggane test site.

29

5.3.1. Reggane atmospheric test site

At the site where the atmospheric tests wereperformed, the areas that have elevated externaldose rates are only a very small part of the tractssurveyed and are confined to distances of a fewhundred metres from the four individual groundzero points. Therefore, for occasional visitors to thesite, exposures to external radiation from residualradionuclides from the tests are likely to be low. Interms of temporary occupancy, the location wherean individual might be within the test site will alsostrongly influence possible doses that might beincurred from inhalation or ingestion of dust that isblown by the wind. Doses for both the mostprobable occupation time at the test site and forupper bounds of exposure for the assumed totaldays of occupancy are shown in Table 9. Probabledoses are less than one tenth of the upper boundvalues.

Activation products, principally 60Co in steelfragments in the immediate vicinity of the groundzero points, are still detectable, but the externalexposure rates from such material are currently toolow to constitute a radiological risk, even if somepieces are removed from the sites. Exposure ratesfrom fragments containing 60Co will decrease byhalf approximately every five years.

Most of the residual plutonium activity nearthe ground zero points is incorporated in the fusedsand. This material has activity concentrations of upto about 1 MBq per kilogram of sand for plutoniumand up to 0.1 MBq per kilogram of sand for 137Cs.Individual pieces of this sand, if removed from thesite, would not give rise to an external radiationhazard. They could only give rise to an inhalation

radiological risk if the removed material wereground into respirable dust without respiratoryprotection.

To complete the assessment of the Regganetest site, possible doses to the inhabitants of thevillage of Reggane arising from inhalation andingestion of wind-borne dust transported from thesite have been estimated. Because of the highlyconservative assumptions in the dose calculations,the present doses are likely to be much less than1 mSv/a.

5.3.2. In Ekker — Taourirt Tan Afella underground test site

Over a small area at the Taourirt Tan AfellaE3 tunnel site, and outside the original fence whichwas constructed in the 1960s at the E2 site, doserates range up to about 240 nGy/h abovebackground. The upper bound to the effective doseabove background (about 80 nGy/h) from externalradiation received by a nomadic herder remainingoutside the original fence for ten days would thenbe about 40 mSv/a. This assumes a factor of 0.7 torelate dose to air to effective dose for 0.66 MeVradiation.

The exposure scenario of persons deliberatelyscavenging or exploring on or in the immediatevicinity of the lava flows from the E2 tunnel is theone which leads to the highest doses estimated forthe former French nuclear test sites. If a personspent one day (eight hours) in an area immediatelyadjacent to or on the lava masses where the doserates averaged 100 mGy/h, the effective dosesreceived from such an exposure scenario would beabout 0.5 mSv. Because the present external dose

TABLE 9. DOSES FOR A THREE DAY TRANSIENT OCCUPATION PERIOD AT THE REGGANETEST SITE

Source Nuclide Maximum probable dose (mSv) Upper bound dose (mSv)

External radiation <2a 12

Inhalation of dust All <1 <1

Ingestion of dust 90Sr 6137Cs 1.2

239+240Pu 32241Am 36

All <9 75

Total <10 87a Assumes occupation in the vicinity of the ground zero points but excludes the exceptional situation of full time occupancy

at Gerboise Bleue ground zero. This would lead to a dose of about 120 mSv over three days.

30

rate is dominated by 137Cs, possible doses willdecline over time according to the half-life of 137Cs,decreasing by one half every 30 years.

Measured soil concentrations of plutoniumare very much lower than at the Reggane site, andfor similar occupancy scenarios, inhalation doses areexpected to be negligible (<1 mSv/a).

Ingestion of soil on foodstuffs handled industy conditions might contribute small doses tonomadic people in the area. As noted, measuredsurface soil activities of plutonium are very muchlower than the peak levels at the Reggane test site,and 137Cs and 90Sr concentrations are comparable tothe mean values in the areas of elevated concentra-tions. If a daily intake of 10 g is assumed, a valuewhich may be extreme for this location, then for theequivalent of ten days spent in the area, annualdoses (committed effective doses) of about 10 mSvare estimated. Concentrations of radionuclides inwell water are below detection limits. The measuredsoil concentrations in the dry watercourse soils aresufficiently low to preclude the possibility ofsignificant concentrations arising in downstreamwells in future years.

The vegetation is sufficiently sparse foranimals led to graze by nomadic herders to bealmost constantly on the move, with at most a fewdays in one area. Livestock movements are alsodictated by distances to available water sources, andanimals would not normally be able to stay in theE2–E3 area for more than a day or two. Grazinganimals could ingest residual radionuclides incorpo-rated in plants through root uptake or deposited onplants as dust. Visual inspection suggested thatdeposited dust would dominate intakes and theconcentrations in the dust would reflect thesurrounding surface soil concentrations. Radio-nuclides ingested by grazing animals andtransferred to meat or milk could contribute toradiation exposures of herders and their families.

However, doses arising from this pathway are small.For the particular case of infants whose dietincludes milk from animals that had been grazing inthe area for a full ten day period, the upper bounddoses are about 12 mSv.

Table 10 summarizes estimates of annualupper bound doses to nomadic herders who aregrazing animals in the vicinity of the E2 and E3tunnels.

5.3.3. Adrar Tikertine experimentation site

The concentrations originally estimated forthe Adrar Tikertine site appear to have beensubstantially reduced by wind and water transport.However, even if the historically estimated concen-trations were applicable, doses arising fromingestion and inhalation of dust would be about twoorders of magnitude lower than those derived forthe Reggane desert, so that for both intake routes,doses of less than 1 mSv/a are estimated.

TABLE 10. DOSES TO NOMADIC HERDERSIN THE VICINITY OF THE E2 AND E3TUNNELS

SourceUpper bound effective dose

(mSv/a)

External radiation 40a

Inhalation of dust <1

Ingestion of dust 10

Ingestion of well water <1

Consumption of products from grazed animals <2b

All 50

a Excludes situation of scavengers working in theimmediate vicinity of the lava.

b Infants drinking milk from grazing livestock mightreceive doses of a few microsieverts per year.

31

6. CONCLUSIONS AND RECOMMENDATIONS

6.1. GENERAL DISCUSSION

This report describes the findings of an expertmission to Algeria and follow-up activities whosepurposes were to collect preliminary radiologicaldata about the former French nuclear test sites, tocollect a limited number of environmental samplesfor radiological analysis and to make a preliminaryevaluation of the current radiological conditions.This assessment was intended to provide guidanceon the need for a more detailed radiologicalmonitoring and assessment programme.

Nevertheless it is considered that theassessment has allowed an adequate evaluation ofthe radiological situation to be made, in spite of therelatively limited sampling and measurementsperformed. However, the supporting measurementdatabase could be broadened and enhanced iffurther samples were collected and analysed.

It was found that most of the areas at the testsites have little residual activity, but that there aretwo exceptions to this. The two sites that have highresidual activity are:

— The Reggane test site at the ground zerolocalities of the Gerboise Blanche andGerboise Bleue atmospheric tests;

— Taourirt Tan Afella in the vicinity of the E2tunnel, where highly radioactive lava wasejected during an underground test.

Two additional areas had lower residualactivity: at Taourirt Tan Afella in the vicinity of theE3 tunnel and at the Adrar Tikertine site where thePollen tests were conducted.

All measurements led to doses which, on thebasis of the assumed scenarios, were not in excess ofsafety standards, so that further sampling wasgenerally not viewed as necessary. Despite therobustness of the present conclusions, it isrecognized that all findings were developed fromwhat would normally be considered a limited andminimal level of sampling. If the objectives offuture monitoring were other than to establishcompliance with safety standards, for example todocument environmental concentrations, carry outa radioecological study, or assess inventory orspecial patterns, then the measurement dataprovided here would be inadequate and wouldrequire supplementation.

Considering the assumed exposure scenariosand pathways, the sites do not give rise to radiationdoses that approach the generic reference level of10 mSv/a above which intervention might beindicated. However, it is worth noting that thelifestyles of nomadic people that might visit thisarea are not thoroughly documented, and hence theestimates of likely dose, as opposed to the upperbound dose, are highly uncertain and should beinterpreted with these caveats in mind.

This assessment finds that environmentalremediation of any of the test areas is not requiredin order to reduce doses below established safetystandards, and possible exposures can be controlledas in the case of Taourirt Tan Afella. However,future decisions by the Algerian authorities toconduct remediation or to further limit publicaccess might be made if economic conditionschange in the area and a more permanent presenceof people is indicated.

6.2. SPECIFIC CONCLUSIONS

6.2.1. Reggane

Probable doses to visitors to the remote deserttest site area at Reggane are estimated to be lessthan a few microsieverts per day. Residual steelfragments and fused sand, if removed from the site,do not present any significant radiological risk.However, if fused sand were ground to respirabledust and people were exposed without respiratoryprotection, this could present an inhalation hazard.

Calculated doses to residents of the town ofReggane from the airborne transport of dust fromthe test areas are predicted to be very low, much lessthan 1 mSv/a.

6.2.2. Taourirt Tan Afella

Nomadic camel and goat herders grazing theirlivestock on the sparse vegetation in the area of theE2 and E3 galleries might receive small doses,principally from external radiation, of less than anestimated 50 µSv/a. Persons scavenging metals inthe immediate vicinity of the lava from the E2tunnel might receive doses of up to about 0.5 mSv in8 hours. Current external exposure rates are lessthan one tenth those existing in 1966. Thesepotential doses are now decreasing annually due to

32

the decay of 137Cs (currently at concentrations up to2 MBq/kg). The assumed exposure scenarios andcurrent doses arising are below the generic inter-vention criterion of 10 mSv/a. The alpha activityconcentration in the lava is in the range between0.04 and 0.4 MBq/kg, which is roughly similar tothat of natural rock with a 0.2% uranium content,and below that of an ore body that would becommercially mined for uranium ore.

6.2.3. Adrar Tikertine

The concentration of plutonium wasdetermined in a small number of sand samples thatwere not sufficient to be representative of the areaand therefore could not be used for a detailed orprecise evaluation of the inventory or special distri-bution of activity in the Adrar Tikertine area.Nevertheless, the activity concentration of anthro-pogenic radionuclides in those samples that weremeasured was generally below laboratory detectionlimits. Thus it is expected that the residual surfacecontamination from the plutonium dispersionexperiments is unlikely to give rise to doses tonomadic herders or their families exceeding 1 mSv/a.

6.3. RECOMMENDATIONS

(a) The integrity of the fence constructed in the1960s at Taourirt Tan Afella, now being

restored by the Algerian local authorities,should be maintained to avoid exposuresarising from human and animal intrusion inthe region around the E2 tunnel entrance orthrough removal of samples of lava from thesite.

(b) The upper bound evaluation of the radio-logical conditions assessed in this preliminarystudy is considered robust, and furtherextended sampling for radiological assessmentis not considered to be necessary. Corrobo-ration of the predicted low inhalation dosesarising from the Reggane site could be readilyachievable through an appropriate airsampling programme, and it is recommendedthat this be carried out.

(c) Similarly, corroboration of the finding thatthere is no dose impact to the local herders inthe In Ekker area should be obtained by anappropriate environmental monitoringprogramme. In particular, water from wellsadjacent to the Tan Afella test site could beanalysed.

(d) Better descriptions of the lifestyles of thepeople that frequent these areas would addcredibility to these findings. Such descriptionsshould be developed primarily by Algerianexperts who are specialists in the appropriatefields but could be supplemented withassistance by IAEA experts familiar with doseassessment methodologies.

33

BLANK PAGE

34

Appendix I

DETERMINATION OF 90Sr, 241Am, Pu AND GAMMA EMITTING RADIONUCLIDES IN THE SAMPLES COLLECTED IN ALGERIA

All radioanalytical measurements and relatedexperimental procedures were conducted at theIAEA’s Laboratories in Seibersdorf, Austria.

I.1. RADIOISOTOPES ANALYSED

The beta emitting radionuclide 90Sr, the alphaemitting 241Am and Pu isotopes, and the gammaemitting radionuclides (241Am, 239Pu, 133Ba, 60Co,137Cs, 152Eu, 154Eu, 155Eu, 40K, 228Ra, 228Th) wereanalysed in selected solid and water samples. Theresults of the radiochemical analyses (beta andalpha emitters) and of the gamma spectrometry(gamma emitters) are shown in Tables 11 and 12,respectively.

I.2. SAMPLE DESCRIPTION

All samples collected and their codes arereported in Tables 13–16. The tables indicate thosesamples that were analysed for 90Sr, 241Am, Puisotopes and the gamma emitters, and those thatwere analysed only for the gamma emitters.Different types of sample were analysed: coarsesand, fine sand (<50 mm), mixtures of sand andblack vitreous fragments of fused sand, blackvitreous fragments of fused sand, and lava. Inaddition, water samples from a well and from aleaching experiment on two solid samples wereanalysed.

I.3. GENERAL PROCEDURE

The general procedure carried out for theanalysis was the following:

(1) The external gamma doses from the sampleswere measured by the laboratory’s radiationprotection personnel.

(2) A preliminary screening by gammaspectrometry was carried out on all samples toprovide the approximate activity levelsneeded for the selection of samples for follow-up analysis. For this screening step, the entireamount of each sample was used ‘as received’,without any processing.

(3) A number of samples were selected for theradioanalytical determination of actinides (Puisotopes and 241Am) and 90Sr by destructiveradiochemical analysis, and of gammaemitting radionuclides using gammaspectrometry, on the basis of the externalradiation dose rates measured at the samplingsites, the preliminary screening of the samplesby gamma spectrometry and informationprovided by the French authorities on thehistory of the nuclear tests.

(4) The samples were physically homogenized,carefully avoiding cross-contamination.

(5) The activity of Pu, 241Am, and fission andactivation products was measured by gammaspectrometry.

(6) The activity of 239+240Pu, 238Pu, 241Am and 90Sr,after sample dissolution and radiochemicalseparation, was measured by alphaspectrometry and liquid scintillation counting.

(7) Leaching experiments were conducted on lavaand black nodule samples.

I.4. ANALYTICAL PROCEDURES

I.4.1. Gamma spectrometric procedures

For the determination of the activity concen-tration of gamma emitting radionuclides, twogamma spectrometric systems were used.

The first system consisted of a high efficiency(70%) coaxial HPGe gamma spectrometer, housedin a low background Pb shield (see Section I.4.10for details). This system was used for themeasurement of the large volume samples that hadnot undergone any processing and were expected tobe heterogeneous. Samples were measured twice toevaluate the reproducibility of the measurements.The samples were placed in standard 240 mLcylindrical polyacrylic containers, and measure-ments were carried out under conditions where thedetector had already been calibrated for photopeakefficiency response as a function of gamma rayenergy.

The second system consisted of a well typeHPGe gamma spectrometer that was used for

35

TAB

LE

11.

AC

TIV

ITY

CO

NC

EN

TR

AT

ION

S (B

q/kg

) O

F A

LP

HA

AN

D B

ET

A E

MIT

TIN

G R

AD

ION

UC

LID

ES

Sam

ple

code

Na

90Sr

241 A

m23

8 Pu

239+

240 P

u

AL

G-1

(sa

nd)

Ave

rage

Ran

geA

LG

-1 (

blac

k m

ater

ial)

Ave

rage

Ran

ge

3 3

4b —

3.2E

+05

b

—

3510

–57

5.9E

+04

c

—

2.0E

+02

60–4

.4E

+02

6.9E

+04

2.2E

+04

–1.2

E+

05

9.1E

+03

4.1E

+02

–3.4

E+

04

3.2E

+06

1.1E

+06

–5.3

E+

06

AL

G-3

Ave

rage

Ran

ge

51.

8E+

053.

4E+

04–7

.1E

+05

1.2E

+04

1.5E

+03

–2.4

E+

042.

2E+

041.

2E+

04–3

.2E

+04

1.2E

+06

1.1E

+06

–1.4

E+

06

AL

G-4

Ave

rage

Ran

ge

56.

1E+

044.

2E+

04–1

.0E

+05

1.8E

+03

1.3E

+03

–2.8

E+

035.

6E+

032.

4E+

03–8

.4E

+03

5.4E

+04

4.9E

+04

–5.7

E+

04

AL

G-8

Ave

rage

Ran

ge

67.

8E+

055.

2E+

05–1

.2E

+06

1.9E

+04

8.0E

+03

–4.4

E+

042.

2E+

041.

6E+

04–3

.7E

+04

3.3E

+05

3.2E

+05

–3.4

E+

05

AL

G-1

1A

vera

geR

ange

51.

1E+

062.

0E+

04–1

.5E

+06

1.2E

+03

1.0E

+02

–2.5

E+

033.

1E+

032.

6E+

03–4

.0E

+03

4.2E

+04

3.9E

+04

–4.4

E+

04

AL

G-1

8A

vera

geR

ange

41.

2E+

042.

0E+

03–3

.2E

+04

2.3

0.4—

3.3

9.6

3.1—

20.2

50.4

22.9

—85

.6

AL

G-2

1A

vera

geR

ange

1<

0.02

—<

0.00

2—

<0.

0002

—<

0.00

03—

AL

G-2

2A

vera

geR

ange

410

<7—

107.

20.

19—

14.3

0.5

0.1—

0.8

144.

8—25

AL

G-2

3A

vera

geR

ange

411

<6—

190.

80.

35—

1.42

1.5

0.1—

3.3

7.4

4.3—

8.8

a N: n

umbe

r of

sub

sam

ples

ana

lyse

d.b O

nly

one

mea

sure

men

t of 90

Sr w

as p

erfo

rmed

.c O

nly

one

mea

sure

men

t of 24

1 Am

was

per

form

ed.

36

TAB

LE

12.

AC

TIV

ITY

CO

NC

EN

TR

AT

ION

S (B

q/kg

) O

F G

AM

MA

EM

ITT

ING

RA

DIO

NU

CL

IDE

S

Sam

ple

code

Na

241 A

m23

9 Pu

133 B

a60

Co

137 C

s15

2 Eu

154 E

u15

5 Eu

40K

228 R

a22

8 Th

AL

G-1

Ave

rage

Ran

ge

21

110

462–

1 75

480

000

<25

000

–140

000

407

320–

493

5045

–54

2 88

01

807–

3 95

715

212

0–18

5<

3.9

<3.

981

33–1

2819

018

6–19

410 9–12

1210

–13

AL

G-3

Ave

rage

Ran

ge

29

000

8 40

0–9

500

650

000

550

000–

740

000

4 44

65

800–

6 52

265

861

9–69

629

026

27 5

63–3

0 48

91

210

1 03

7–1

382

419

399–

439

695

639–

750

<17

<17

AL

G-4

12

300

<23

0 00

03

727

1 02

931

711

7 10

81

261

824

<40

AL

G-1

11

1 40

0<

1 60

0 00

0<

1 40

01

050

2 12

0 00

0<

1 10

0<

400

320

AL

G-1

21

13 0

00<

1 10

0 00

04

696

3 61

067

2 98

96

651

1 60

62

956

270

AL

G-1

31

3 00

0<

1 00

0 00

074

91

707

1 54

4 39

01

158

315

617

310

AL

G-1

41

940

<43

4 00

026

864

01

030

156

386

101

244

141

AL

G-1

51

1 70

0<

1 87

0 00

0<

1 60

01

159

2 52

1 04

6<

1 30

0<

470

226

<36

6

AL

G-1

8A

vera

geR

ange

2<

22<

22<

39 0

00<

39 0

00<

6<

62.

82.

83

457

3 45

7<

7<

7<

5<

528

.427

.8–2

8.9

1 14

01

140

169.

215

3.7–

184.

716

6.0

148.

5–18

3.4

AL

G-2

11

<0.

3<

600

<0.

1<

0.07

2<

0.07

5<

0.13

<0.

1<

0.16

<0.

8<

0.27

<0.

12

AL

G-2

2A

vera

geR

ange

2<

8<

8<

14 0

00<

14 0

00<

2<

2<

1<

12.

01.

37–2

.68

<3

<3

<2

<2

<4

<4

532

507–

558

16.2

14.0

–18.

417

.116

.0–1

8.4

AL

G-2

3A

vera

geR

ange

223

.623

.2–2

4.1

<12

000

<12

000

<1.

9<

1.9

<1.

1<

1.1

4.4

3.43

–5.4

6<

2.7

<2.

7<

1.9

<1.

9<

4.1

<4.

155

755

726

.823

.0–3

0.7

26.6

23.9

–31.

3a N

: num

ber

of s

ubsa

mpl

es a

naly

sed.

37

measurement of small volume (<5 mL) samples thathad been homogenized and contained elevatedlevels of Pu and 241Am. In this case, a standardcounting vial was filled with approximately 1 mL of

sample material. The gamma ray spectrometer hadbeen calibrated for photopeak efficiency responseas a function of gamma ray energy for this samplegeometry before the measurements were made. The

TABLE 13. REGGANE — SAMPLES OF SAND AND BLACK VITREOUS FRAGMENTS OF FUSEDSAND

Code Sample type CoordinatesDose rate

(nSv/h)Location, comments

ALG-1a Sand with black fragments of fused sand, 1526 g

26∞09'763" N00∞06'255" W

~500 Gerboise Blanche, surface test, <10 kt

ALG-2 Sand with black fragments of fused sand, 1260 g

26∞09'804" N00∞06'191" W

~950 Gerboise Blanche, surface test, <10 kt

ALG-3a Sand with black fragments of fused sand, 502 g

26∞09'804" N00∞06'208" W

~600 Gerboise Blanche, surface test, <10 kt

ALG-4a Black fragments of fused sand, 468 g

26∞18'704" N00∞03'421" W

~4000 Gerboise Bleue, ground zero, 100 m tower test, ~60 kt

ALG-5 Sand, 1574 g 26∞18'704" N00∞03'421" W

~4000 Gerboise Bleue, ground zero, 100 m tower test, ~60 kt

ALG-6 Corroded metal, 374 g 26∞18'704" N00∞03'421" W

Not known Gerboise Bleue, 100 m tower test, ~60 kt

ALG-7 Sand, 780 g 26∞21'098" N00∞07'405" W

~200 Gerboise Rouge, 50 m tower test,<10 kt

a Samples analysed for 90Sr, 241Am, Pu isotopes and gamma emitters.

TABLE 14. TAOURIRT TAN AFELLA — LAVA SAMPLES COLLECTED WHERE THE PARTIALLYCONFINED TEST OCCURRED

Code Sample type Coordinates Dose rate (mSv/h) Location

ALG-8a Lava, crystalline, 148 g

24∞03'819" N05∞03'408" E

30 In front of the E2 tunnel from which radioactive lava was ejected

ALG-9 Lava, porous, red, 120 g 24∞03'812" N05∞03'400" E

4 Same

ALG-10 Lava, porous, red, 98 g 24∞03'822" N05∞03'331" E

200 Same

ALG-11a Lava, porous, yellow/white, 81 g

24∞03'512" N05∞03'220" E

10 Same

ALG-12b Lava, crystalline, 176 g 24∞03'819" N05∞03'408" E

30 Same

ALG-13b Lava, porous, red, 158 g 24∞03'812" N05∞03'400" E

4 Same

ALG-14b Lava, porous, red, 111 g 24∞03'822" N05∞03'331" E

200 Same

ALG-15b Lava, porous, yellow/white, 42 g

24∞03'512" N05∞03'220" E

10 Same

a Samples analysed for 90Sr, 241Am, Pu isotopes and gamma emitters.b Samples analysed only for gamma emitters.

38

resultant gamma ray spectra were processed usingcommercial peak search and nuclide identificationsoftware.

The measurements from both systems werecorrected for background radiation, and also forattenuation due to differences between the massdensity and atomic composition of the samplematrix and the standard. In the case of the well typedetector, the results were further corrected for truecoincidence summing (cascade summing). For thislatter correction, several single-photon energysources were prepared, and the total countingefficiency of the well detector was determined at

several energies that spanned the energy region ofthe gamma rays of the radionuclides of interest. Thecorrection factors for true coincidence summingwere calculated with the KORSUM software (PTBBraunschweig, Germany).

In addition to the solid samples, a series ofwater samples from two leaching experiments weremeasured. The leaching experiments wereperformed on two samples: ALG-8 and ALG-3. Theleaching experiments were carried out at 40oCaccording to a standard American Society forTesting and Materials (ASTM) procedure for theleaching of nuclear waste forms with volumes of

TABLE 15. TAOURIRT TAN AFELLA — SEDIMENT, SAND, VEGETATION AND WATER SAMPLESCOLLECTED NEAR THE TUNNEL WHERE THE PARTIALLY CONFINED TEST OCCURRED

Code Sample type Coordinates Dose rate (nSv/h) Location, comments

ALG-16 Soil sediments from a dry stream bed, 316 g

24∞03'770" N05∞03'992" E

~800 In the proximity of the old French fence, 0.8 km from the E2 tunnel. Collected to evaluate possible radionuclide transport

ALG-17 Soil sediments from a dry stream bed, 439 g

24∞03'580" N05∞03'985" E

~800 Same as above but 400 m from sample ALG-16

ALG-18a Sand, 914 g 24∞03'736" N05∞03'542" E

~800 Same

ALG-19 Vegetation 24∞03'736" N05∞03'542" E

~800 Same

ALG-20 Water used for washing sample ALG-19

24∞03'736" N05∞03'542" E

~800 Same

ALG-21a 1.5 L of well water (divided between two containers)

24∞00'959" N05∞04'805" E

Background 6 km NW of well 1(24∞04'003" N05∞03'805" E)

a Samples analysed for 90Sr, 241Am, Pu isotopes and gamma emitters.

TABLE 16. ADRAR TIKERTINE — SAND SAMPLES COLLECTED AT THE SITE OF THE POLLENEXPERIMENTS

Code Sample type Coordinates Dose rate Comments

ALG-22a Sand, first layer, ~3 mm, 270 g 23∞55'958" N04∞43'343" E

Not available Sand presumably containing Pu and Am

ALG-23a Sand, second layer, ~3 mm, 743 g

23∞55'958" N04∞43'343" E

Not available Same

ALG-24 Sand, first layer, ~3 mm, 534 g 23∞55'569" N04∞43'983" E

Not available Same

ALG-25 Sand, second layer, ~3 mm, 1163 g

23∞55'569" N04∞43'983" E

Not available Same

a Samples analysed for 90Sr, 241Am, Pu isotopes and gamma emitters.

39

240 mL and 90 mL, respectively. The measuringtime for these samples ranged from 20 to 70 hours.No gamma emitting radionuclides were detectedabove the background.

The minimum detectable activity concen-tration for the radionuclides of interest wascalculated according to Ref. [6], and typically was~3 Bq/kg for 241Am and ~0.5 Bq/kg for 137Cs.

I.4.2. Radiochemical procedures

Two sample dissolution methods were applied:conventional wet digestion and fusion with lithiummetaborate, as discussed in section 1.2 of Ref. [7].

Most of the analyses were carried out applyinga sequential procedure for the determination of241Am, 90Sr and Pu radionuclides. A few analysescarried out on small aliquots taken from highactivity samples after dissolution and dilutionof the sample did not involve any radio-chemical separation for Pu other than the micro-coprecipitation of Pu(IV) with NdF3. Also, for 90Sradditional analyses were performed withoutapplying a sequential procedure. Plutonium radio-isotopes and 241Am were analysed by using theprinciple of isotope dilution alpha spectrometry.Strontium-90 was measured by liquid scintillationcounting using the double energy window method.

I.4.3. Sample crushing

Owing to the very heterogeneous nature ofsome of the samples collected, selected samples hadto be partially or fully homogenized by crushingprior to analysis. Because of the limitations andrestrictions on working with high activity dust, thereduction of particle size was carried out only forselected samples. Samples ALG-3, ALG-4,ALG-12, ALG-13, ALG-14 and ALG-15 weretotally or partially crushed before measurement. Allcrushed samples had ‘P1’ added to the samplenumber. To perform the crushing, the samples werecarefully transferred into a steel container (10 cm indiameter and 15 cm in height). The container andthe crushing pestle were wrapped with plastic fixedwith adhesive tape to avoid release of any dust.Each sample was mechanically crushed using a largehammer and the pestle. The sample was thentransferred back to the storage container. To avoidcross-contamination, the samples were crushed inthree different containers. Samples ALG-13,ALG-14 and ALG-15 were crushed in container 1in the order ALG-14, ALG-13, ALG-15, i.e. in

order of increasing activity concentration (prelim-inary gamma measurements). The container andpestle were cleaned with paper and with a vacuumcleaner between samples. Sample ALG-4 wascrushed in container 2 and ALG-12 in container 3.Container 2 was also used for sample ALG-3 after ithad been cleaned with a decontamination liquid anddried. Samples ALG-4 and ALG-12 were onlypartially crushed.

To avoid contamination, the samples wereprepared in a separate room suitable for work withhigher activity. The tables were appropriatelyprotected and the work was performed under anexhaust system with a high exhaust rate.Appropriate procedures were followed and theanalysts used protective clothing consisting of filtermasks, gloves, disposable coats and overshoes. Ahealth physicist was present at all times.

The handling of the higher activity samples(ALG-1, ALG-8 and ALG-11) was done usingsealed plastic boxes inside a fume hood. Subsamplesfrom ALG-8 were taken using an electric hand drillwith a 5 mm diameter carbide drill bit.

All other samples were measured as collected.

I.4.4. Sample dissolution

Samples to be analysed for beta and gammaemitters were dissolved. Two sample dissolutionmethods were applied: conventional wet aciddissolution for low activity samples and lithiummetaborate fusion for both high and low activitysamples.

The conventional wet acid dissolution methodwas used for one run of analyses (Set 3) of the lowactivity samples (ALG-22, ALG-23 and ALG-18).This is described in section 2.1 of Ref. [7].

A total dissolution method based on fusionwith LiBO2 was applied for the decomposition ofmost of the samples. The samples were fused withlithium metaborate using a sample/flux ratio of 4:1.Any insoluble residue that remained after fusionand dissolution in 1 mol/L HNO3 was separated byfiltration. The residues were dissolved with amixture of concentrated HNO3/HF acids. Afterevaporation with concentrated HNO3, the residueswere dissolved in 10–20 mL of 1 mol/L HNO3. Theresultant solution was combined with the main1 mol/L HNO3 solution and diluted to either 200 or250 mL with 1 mol/L HNO3. The dilution factor(ratio of mass of solution after dilution to theoriginal mass of sample that was fused) wasrecorded.

40

I.4.5. Sample size and tracer activities

Small aliquots of the diluted solutions wereused to measure by liquid scintillation counting thegross alpha plus beta activities. This informationwas needed to evaluate the tracer activities to beadded and the sample size necessary for the radio-chemical analysis.

I.4.6. Separation of particle fraction <50 µm

The sand fraction having a diameter of <50 mmwas isolated in samples ALG-1, ALG-22 andALG-24 using a 50 mm sieve (DIN standard). Ineach case the volume of the fine material was� 1 mL. The material was then measured forapproximately 20 hours using a well type detector(Canberra model GCW2022-7500SL) using astandard counting vial. The results, corrected for thecontribution of natural background activity andspectral interference and for true coincidencesumming, are reported in Table 16.

I.4.7. Radiochemical separation procedures

A combined sequential procedure for thedetermination of 90Sr, 241Am and Pu radionuclideswas generally applied [7–9]. In some cases thinsources of Pu were prepared by micro-coprecipi-tation without performing any radiochemicalseparation other than the micro-coprecipitationwith NdF3. In a few cases, in order to improveprecision, 90Sr was analysed separately [10].

I.4.7.1. Combined radiochemical separation procedure using extraction chromatography and anion exchange

The radiochemical procedure involved theseparation of Pu from Am and Sr by extractionchromatography after the preconcentration of Amand Sr by coprecipitation with Ca/Ba/Mg oxalates.Plutonium had to be reduced before performing theoxalate precipitation. The reduction was carried outby reducing any Fe(III) to Fe(II) with 1 mL ofconcentrated hydrazinium hydroxide in 1 mol/LHNO3. The mixed oxalates containing Pu, Am andSr were destroyed with concentrated nitric acid.Then the residues were dissolved in 1 mol/L HNO3.Before the radiochemical separation wasperformed, the oxidation state of Pu was adjusted tothe tetravalent state. The procedures for theoxidation state adjustment of Pu are indicated in

Ref. [7]. When no Fe(III) was observed inthe samples, 0.1 g of Mohr’s salt was added to the1 mol/L HNO3. To ensure the complete reduction ofPu, 1 mL of concentrated hydrazinium hydroxidewas added by stirring to the hot 1 mol/L HNO3

solution. The adjustment to the tetravalentoxidation state of Pu was carried out by addingbetween 0.65 and 1.0 g of NaNO2 to the 4 mol/LHNO3 solution. After boiling for approximately1 min, the solution was cooled and the nitricacid concentration was adjusted to approximately8 mol/L HNO3. The total volume of this solutionwas approximately 40 mL at this stage. The solutionwas then passed through columns of TEVA Resin(EIChroM Industries, Inc.) with approximately2 mL bed volume. The columns were washed with20 mL of 8 mol/L HNO3 to remove non-retainedions (Sr and other alkaline earth metals, Am andrare earth elements, K and other alkaline metals,etc.). From each column, Th was separated with12 mL of 10 mol/L HCl. Plutonium was finallyseparated by passing through the columns 25 mL of0.1 mol/L NH4I/9 mol/L HCl. The Pu fractions wereconverted to nitrate form by evaporating to a thickpaste three times with 2 mL HNO3. The residueswere dissolved in 20 mL of 1 mol/L HNO3. Theprocedure described in section 2.1 of Ref. [7] wasfollowed to ensure a higher decontamination fromU. Thin sources for alpha spectrometric measure-ments of Pu and Am were prepared by micro-coprecipitation with NdF3. Americium wasseparated from Sr by extraction chromatographyusing TRU Resin (EIChroM Industries, Inc.). Thefinal Sr separation and purification were performedby extraction chromatography using Sr Resin(EIChroM Industries, Inc.). The detailed radio-chemical procedure for Am and Sr can be found insections 2.2–2.5 of Ref. [7]. Americium was notseparated from rare earth elements.

I.4.7.2. Separation of Pu by ion exchange

The process of Pu separation by ion exchangeis described in detail in section 2.1 of Ref. [7].

I.4.7.3. Direct micro-coprecipitation with NdF3

For high activity samples (ALG-3, ALG-4,ALG-8 and ALG-11), a direct micro-coprecipi-tation of Pu with NdF3 was carried out from smallaliquots taken from the diluted solutions. Theprocedure for Pu source preparation is described insection 2.1 of Ref. [7].

41

I.4.7.4. Determination of 90Sr

In addition to the combined sequentialprocedure, 90Sr was also determined separately, inaliquots taken from diluted solutions of high activitysamples. In this case, 90Sr was coprecipitated as Ca/Mg/Ba oxalate as described in section 2.2 of Ref. [7].The purification of Sr from alkaline earth metalswas carried out by extraction chromatography usingSr Resin as indicated in section 2.5 of Ref. [7].

I.4.8. Analysis of 137Cs, Pu isotopes, 241Am and 90Sr in well water

Well water (1.5 L) was filtered through amembrane 0.2 µm filter. The filtrate was used forthe radiochemical analysis of 137Cs, Pu isotopes,241Am and 90Sr. The residue was measured for grossalpha/beta activities using a proportional counterand for gamma activities using a high resolution Ge(Li) semiconductor detector [7]. Caesium waspreconcentrated from the filtrate by using themethod based on the selective adsorption oninsoluble ammonium molybdatephosphate [10].The yellow precipitate was separated by filtrationthrough a membrane polypropylene filter. Thesolution was evaporated to approximately 200 mLafter the addition of Pu and Am radiotracers and20 mg of Sr carrier. The previously describedsequential determination of Pu isotopes, 241Am and90Sr was followed.

I.4.9. Leaching experiments

The leaching experiments were carried out at40oC using deionized water as leachant. The twospecimens, ALG-3 and ALG-8, were first washedfour times with 90 mL of deionized water toremove dust and fragments. They were thentransferred to a container filled with 90 mL of theleachant. After 30 days the leachant was filteredthrough a 0.2 mm polypropylene membrane (45 mmdiameter) and the pH was adjusted to 1 with HNO3.After determination of the gamma emitting radio-nuclides, the solution was analysed for 239+240Pu,241Am and 90Sr.

I.4.10. Instrumentation

I.4.10.1. Gamma spectrometry

The low level counting system used consistedof:

(a) Detector: HPGe model GEM-XX185-S(EGG Ortec) with 70% efficiency relative to3 in ¥ 3 in 4 of NaI crystal, resolution of 2.5 keVat 1.3 MeV with a low level cryostat (selectedmaterials of low radioactivity were used forconstruction), mounted in a 10 cm thick lowlevel Pb shield;

(b) Automatic sample changer supplied by EGGOrtec;

(c) Nuclear spectroscopy electronics: Ortecmodel 660 HV power supply, Canberra model2025 amplifier, Canberra model 8075 ADC,Canberra S-100 Microchannel MCA board.

The counting system, based on a well typedetector, consisted of:

(1) Detector: well type HPGe model CanberraGCW2022-7500SL with 18% efficiencyrelative to 3 in ¥ 3 in of NaI crystal, resolutionof 1.9 keV at 1.3 MeV, mounted in a 10 cmthick Pb shield;

(2) Nuclear spectroscopy electronics: Ortecmodel 459 HV power supply, Canberra model2025 amplifier, Canberra model 8075 ADC,Canberra AIM 556 acquisition interfacemodule.

Details of the settings of each of the systemsare documented in the detector dedicated files. Thesoftware used was Genie-2000 version 1.4 byCanberra.

I.4.10.2. Alpha spectrometry and liquid scintillation counting

Alpha spectrometry and liquid scintillationcounting are described in detail in the chapters on‘Apparatus’ and ‘Calculation and calibration’ inRef. [7].

I.4.11. Metrological parameters

The minimum detectable activities of thealpha spectrometry system and the liquid scintil-lation counter were calculated on the basis ofCurrie’s method [6]. The combined uncertainty inthe activity concentration was calculated algebrai-cally and/or using the spreadsheet method ofKragten [11].

4 1 inch = 2.54 cm.

42

I.4.12. Quality control

In order to assess reproducibility in themeasurements, different radiochemical procedureswere applied to the analysis of relevant radio-nuclides in the selected samples. The reproducibilityof the results obtained in most of the samples (lavaand black fragments of fused sand) was good, takinginto consideration that not all samples weremechanically homogenized. Recoveries for Pu, Amand Sr were generally higher than 65%, whichindicates that the radiochemical proceduresperformed well in the analysis of this type ofsample. Two IAEA reference materials (IAEA-135and Soil-6) were analysed in parallel with thesamples. Results for Pu, 241Am and 90Sr were withinthe confidence intervals of the reference valuesafter corrections for ingrowth (241Am/241Pu), decay(241Pu, 90Sr), etc.

I.5. RESULTS AND DISCUSSION

The results of the radiochemical analyses(beta and alpha emitters) and of the gammaspectrometry (gamma emitters) are shown in Tables11 and 12, respectively.

I.5.1. Reggane samples

In sample ALG-1 from Reggane (compositeof sand and black fragments of fused sand), most ofthe activity was found in the black fused sand. Theanalysis carried out on subsamples that containedonly the black fused sand showed activity concen-trations for 239+240Pu of the order of 1 ¥ 106 Bq/kg.The activity in the sand was three to four orders ofmagnitude lower. Sample ALG-3 was also acomposite with black fragments of fused sand andsand. In this case the results for all subsamplestaken for the black fragments were very repro-ducible, showing that Pu is homogeneouslydistributed throughout this material. The activityconcentrations of all measured anthropogenicradionuclides in the sand fraction containingparticles with a diameter of <50 mm were in generalequal to or less than the level of detection (a fewtens of becquerels per kilogram). The onlymeasurable radionuclides were 137Cs and thenatural isotopes 40K, 228Ra and 228Th. The activityconcentration was 196 Bq/kg for 137Cs and wasabout 300 Bq/kg for 40K, 228Ra and 228Th.

One sample consisting of 5 g of black fusedsand (from sample ALG-3 from Reggane, Gerboise

Blanche) was also leached by water at 40oC. Afterthe sample was washed with distilled water toremove particles and dust, the activity concentra-tions of 137Cs, 90Sr, 241Am and 239+240Pu in theleachate were measured after a period of 30 days.The radionuclides in the leachate were alwaysbelow or at the minimum detectable activity, i.e. lessthan approximately 1 Bq/L for 137Cs, less thanapproximately 0.03 Bq/L for 90Sr, less than approxi-mately 1 ¥ 10–3 Bq/L for 241Am and less thanapproximately 0.02 Bq/L for 239+240Pu. The lowradionuclide activity in the leachates in the timeinterval of the experiment could indicate that theradionuclides are immobilized in the matrix of thevitreous fused sand. However, further and morerepresentative experiments should be conductedbefore confirming this conclusion.

I.5.2. In Ekker — Taourirt Tan Afella samples

As expected, the lava samples ALG-8 andALG-11 from Taourirt Tan Afella, collected in frontof the tunnel where the partially confined testoccurred, were highly radioactive. The activities of239+240Pu, 241Am and 90Sr seem to be very homogene-ously distributed in this type of sample. The activityconcentration of 239+240Pu ranges between 1 ¥ 104

and 1 ¥ 105 Bq/kg. For 241Am the activity concen-tration ranges between 1 ¥ 103 and 1 ¥ 104 Bq/kg.For 90Sr the activity concentration ranged between1 ¥ 104 and 1 ¥ 106 Bq/kg. Sample ALG-8,consisting of 148 g of lava, was also leachedfollowing the same procedure as mentioned above.Also in this case, after 30 days of leaching the radio-nuclides in the leachate were always below or at theminimum detectable activity.

The activity concentrations of all gammaemitters and of 239+240Pu, 241Am and 90Sr in the watersample (ALG-21) taken from a well about 6 kmbeyond the perimeter of the old fence that had beenerected by the French authorities and thatsurrounds the area affected by the partiallyconfined test were below the minimum detectableactivity.

In sample ALG-18, which was collected in theproximity of the old fence, slightly higher activitiesfor Pu, Am and Sr were observed.

I.5.3. In Ekker — Adrar Tikertine samples

Samples ALG-22 and ALG-23 from AdrarTikertine consisted of sand collected at the sitewhere the Pollen experiments were conducted. The

43

activity concentrations for Pu radioisotopes, 241Amand 90Sr in ALG-22 and ALG-23 were below25 Bq/kg. The two sand samples (ALG-22 andALG-24, see Table 17) were sieved and the sandfraction containing particles with a diameter of<50 mm was measured by high resolution gammaspectrometry. As in the case of the sample fromReggane (Gerboise Blanche), the activity concen-trations of all anthropogenic radionuclides were ingeneral equal to or less than the level of detection (afew tens of becquerels per kilogram). The onlymeasurable radionuclides were 137Cs and thenatural isotopes 40K, 228Ra and 228Th. The activityconcentration was about 25 Bq/kg for 137Cs and wasabout 300 Bq/kg for 40K, 228Ra and 228Th.

I.6. CONCLUSIONS

Selected samples have been analysed by highresolution gamma spectrometry and alpha and betaspectrometry after radiochemical separation. Theconcentrations of the following radionuclides havebeen determined:

133Ba, 60Co, 137Cs, 152Eu, 154Eu, 155Eu, 40K, 228Ra, 228Th (gamma emitters);90Sr (beta emitter);241Am, 238Pu, 239+240Pu (alpha emitters).

The number of samples collected and analysedis somewhat small when viewed against the size ofthe sites visited during the field mission. Thisrestricts to some extent the validity of conclusionsbased on extrapolating the laboratory measure-ments to the entire areas potentially affected by thenuclear tests. Nevertheless, keeping in mind thislimitation, some general conclusions can still bedrawn.

I.6.1. Samples from Reggane

The only site at Reggane from which sampleswere taken and where significantly elevated radio-nuclide concentrations were detected is GerboiseBlanche. This is the site of the only test conductedon the surface (<10 kt). Most of the contaminationis in the black, vitreous and porous material (sandmelted at the time of the explosion and then solid-ified). The sand is much less active (100–1000 timesless). A typical sample is ALG-3 (sand with manyblack fragments of fused sand), which has thefollowing activity concentrations:

239+240Pu = 1.2 × 106 Bq/kg;137Cs = 2.9 × 104 Bq/kg;90Sr = 1.8 × 105 Bq/kg.

The activity concentrations of the anthropo-genic radionuclides in the sand fraction containingparticles with diameters of <50 mm were equal to orless than the level of detection (a few tens ofbecquerels per kilogram). The only activity concen-tration that was measurable was 137Cs at 196 Bq/kg.This indicates that the activity concentrations of theradionuclides generated by the nuclear tests in thesand fraction that is respirable (<10 mm) should benegligible.

I.6.2. Samples from In Ekker — Taourirt Tan Afella

Taourirt Tan Afella is the location whereseveral tunnel tests were conducted. The only sitefrom which samples were taken was the area infront of the E2 tunnel where the partially confinedtest occurred (ejection of radioactive lava) and itsproximity. As expected, the activity of the lava washigh. Activity concentrations in a typical lavasample (ALG-11) were:

239+240Pu = 4.2 × 104 Bq/kg;137Cs = 2.1 × 106 Bq/kg;90Sr = 1.1 × 106 Bq/kg.

The activity in the water taken from a well inthe proximity (about 6 km) of this site (sampleALG-21) was negligible, i.e.:

137Cs < level of detection (0.075 Bq/kg);90Sr < level of detection (0.02 Bq/kg).

This result indicates that at present there is noevidence that drinking the well water involves anyradiological risk.

The soil and sand in the dry stream bedscoming from the radioactive lava (ALG-18) had thefollowing activity concentrations:

239+240Pu = 50 Bq/kg;137Cs = 3.5 × 103 Bq/kg;90Sr = 1.2 × 104 Bq/kg.

I.6.3. Samples from In Ekker — Adrar Tikertine

The activity concentrations of 239+240Pu, 137Csand 90Sr in the coarse sand samples were low. They

44

TABLE 17. ACTIVITY CONCENTRATION OF GAMMA EMITTING NUCLIDES IN THE SANDFRACTION WITH A DIAMETER OF <50 µm IN SAMPLES ALG-22, ALG-24 AND ALG-1

NuclideActivity

concentration(Bq/kg)

Standarduncertainty

(Bq/kg)

LODa

(Bq/kg)Status

ALG-22

241Am 36.5 3.3 17133Ba 138 <LOD60Co 56 <LOD134Cs 80 <LOD137Cs 28.5 8.6 27152Eu 114 <LOD154Eu 43 <LOD155Eu 48.6 5.2 2740K 618 <LOD239Pu 171 000 <LOD228Ra 224 36 167228Th 214 22 39

ALG-24

241Am 7.6 <LOD133Ba 60 <LOD60Co 22 <LOD134Cs 33 <LOD137Cs 23.0 3.9 12152Eu 42 <LOD154Eu 15 <LOD155Eu 43.0 2.8 1140K 484 73 217239Pu 41 300 <LOD228Ra 262 16 59228Th 285 23 12

ALG-1

241Am 27.3 1.3 7.1133Ba 55 <LOD60Co 19 <LOD137Cs 196.5 7.6 13152Eu 69.9 8.6 28154Eu 15 <LOD155Eu 47.7 2.9 8.440K 306 78 249239Pu 32 600 <LOD228Ra 300 18 72228Th 309 23 12

a LOD: limit of detection.

45

fell in the range 2–15 Bq/kg. The activity concen-tration of plutonium in the sand fraction containingparticles with a diameter of <50 mm was also equalto or less than the level of detection. This indicatesthat significant quantities of 239+240Pu (or otheranthropogenic radionuclides) released during thePollen tests should not be present in the sandfraction that is respirable (<10 mm).

I.7. PERSONNEL

The work was carried out at the IAEA’sLaboratories in Seibersdorf under the direction and

scientific responsibility of P.R. Danesi. Thefollowing staff members were involved in the work:E. Zeiller (sample preparation), M. Makarewicz(sample preparation, gamma measurements),G. Kis Benedek (sample preparation, radiochemicalanalysis of 90Sr, analysis of well water sample,leaching of lava and black nodules), L. Benedik(sample preparation; radiochemical analysis of Puradioisotopes, 241Am and 90Sr; calculations),J. Moreno (sample preparation; radiochemicalanalysis of Pu radioisotopes, 241Am and 90Sr; calcu-lations; evaluation of results; drafting of the report),K. Burns (coordination, evaluation of results,revision of the report).

46

Appendix II

ASSESSMENT OF RADIATION DOSES

II.1. REGGANE

The principal exposure pathways at theReggane test site are:

— External radiation;— Inhalation of dust;— Ingestion of dust.

A short term stay or a series of short stays atthe Reggane desert test site amounting to up tothree days per year was postulated as the upperbound on likely occupancy for the foreseeablefuture.

II.1.1. External exposure

The background dose rate to air in the regionwas about 80 nGy/h. The maximum dose raterecorded at 1 m height (at about the ground zero ofthe Gerboise Bleue test) was about 2.5 mGy/h,which, since 137Cs is the dominant contributor,implies a peak activity concentration of the order of5 MBq/m2 of 137Cs (or about 50 kBq/kg, assuminguniform deposition to a depth of 5 cm). The peakmeasured activity concentration of 30 kBq/kg isconcordant with these values although some lossthrough transport of the surface soil by the wind hasoccurred. For Gerboise Blanche the peak externaldose rate was about 1 mGy/h, and for GerboiseVerte and Rouge the maximum rates were only ofthe order of 2–3 times above background. The testswere conducted within a total area of about 10 km ×20 km, or about 200 km2. Even for the GerboiseBleue site the dose rates were near background at adistance of 800 m from ground zero, so that the totalarea with elevated exposure rates within the200 km2 test zone was only about 2 km2, or 1%. Aperson camping in the area and choosing a campsiterandomly would with high probability be at a sitewhere exposure rates are at the background level.In the extremely unlikely scenario that the GerboiseBleue ground zero point were selected, the effectivedose accumulated from external exposure over theassumed maximum of three days would be about0.1 mSv/a. For the assumed exposure scenario(camping occasionally in the general test area) the

most probable annual dose from nuclear testresidues would be negligible.

Some pieces of scrap steel exist in the testzones that still exhibit detectable 60Co activation.The exposure rate from these pieces is too low torepresent a radiological hazard even if materialwere taken as souvenirs and kept in fairly closeproximity to people.

II.1.2. Inhalation of dust

In windy conditions the dust loadings in the airnear ground level can be very high. Information onthe frequency of such conditions is lacking. It islikely that in extremely dusty conditions, e.g. duststorms, protective measures are taken (such asrespiratory protection, sheltering in tents orindoors) against inhalation and ingestion of dust.For the extremely dusty living conditions ofaborigines studied in the Maralinga assessment [12],a mean airborne dust loading of 1 mg/m3 wasassumed, with a 90 percentile value of 3 mg/m3.These values will be adopted here because sitespecific data are not available.

For persons who might be in the areaimmediately downwind of an area with elevatedconcentrations of residual activity, the inhalationactivity intake rate is dependent on wind velocityand therefore dust loading and aversion measures.Assuming dusty conditions with 1 mg/m3 of soil inair and an adult inhalation rate of 23 m3/d, theinhaled mass intake is 23 mg/d, or for constantextremely dusty conditions about 3 to 5 times thisquantity. It is evident that much of the dusttransported by wind in the desert has been movedto and fro over long periods, and much of theinhaled dust in the proximity of the test sites willhave originated elsewhere.

Plutonium is the major contributor toinhalation dose because of its higher committedeffective dose per unit intake factor, and highersurface soil concentration at the test sites. The dataprovided by the French authorities indicate thatpeak 239+240Pu concentrations are about 4 MBq/m2

at the Gerboise Blanche, Rouge and Verte sites, andrather lower at the Bleue site. Assuming a uniformdeposition to a depth of 0.5 cm and a soil density of

47

2000 kg/m3, this implies a concentration of about0.4 MBq/kg. The peak concentration measured atBlanche was about 1 MBq/kg, which is within abouta factor of 2 of the implied value. Assuming anexponential fall-off (to 2% of the peak) with radiusout to a distance of 800 m from ground zero in thecase of the Blanche site, an area of about 2 km2 hasresidual plutonium activity at a mean concentrationof about 0.1 MBq/kg, with smaller areas having thisconcentration at the Rouge and Verte sites and alower mean concentration at the Bleue site. Theairborne source generating area can then for calcu-lational purposes be approximated by a meanconcentration of about 0.1 MBq/kg over an area of2.5 km2 (Table 18).

For the equivalent of three days in a yearspent in a downwind direction from the test sites,the activity intake upper bound for 239+240Pu istherefore less than 9 Bq. The upper bound to theannual dose for this scenario is then derivable fromthe respirable fraction of airborne dust, modified byany enhancement factor. In view of the constantmovements of desert dust, the enhancement factoris likely to be less than 1. For a respirable fraction ofr%, the upper bound to inhalation dose (committedeffective dose) from 239+240Pu is then less than1.4r mSv (assuming slow clearance for the oxideform and a dose coefficient of 1.6 × 10–5), or inconstant extremely dusty conditions a few timesgreater than this. Again, on the basis of randomlyselected camping locations within the test area andvariable wind directions, the annual dose to personsbehaving as in the assumed scenario would be muchsmaller. Further, the peak concentrations ofplutonium measured were in fused sand, whichgenerally contributes little to respirable particulatesunless it is finely broken up by natural forces andprocesses or human activities. The activity concen-trations in surface layers of sand are 2–3 orders of

magnitude lower. In reality, for the GerboiseBlanche sand sample, ALG-3, the measured activityconcentrations of anthropogenic radionuclides inthe sand fraction of particle size below 50 mm wereequal to or below the limits of detection. Thepostulated maximum inhalation doses arising fromthis exposure scenario are therefore negligible.

The committed effective dose per unit activityintake factors have been taken from the Interna-tional Basic Safety Standards for Protection againstIonizing Radiation and for the Safety of RadiationSources [3] and are shown in Table 19.

II.1.3. Ingestion of dust

Dust may settle on clothing, skin andfoodstuffs, and so be transferred to the mouth andingested. For the extremely dusty and high dust tofood transfer processes associated with aboriginelife styles [12], an ingestion rate of 10 g/d wasassumed. If this value is applied, the upper boundsfor ingested activities of contributing radionuclidesarising from three days of camping in a contami-nated area are the mean soil activities (Table 18)times 30 g. Camping in the 98% of the test site areawith little residual activity would lead to muchsmaller doses.

Plutonium pellet experiments

In the future some contaminated soil from theplutonium pellet experiments could potentially beunearthed and give rise to an inhalation risk. Thespecific sites of the experiments are moderatelyraised above the surrounding soil but can only beidentified after diligent searching. A few of theexperiments that were not totally contained mayhave given rise to some very localized soilcontamination.

TABLE 18. CONCENTRATIONS (Bq/kg) USED TO ESTIMATE DOSES

NuclideMeasured peak concentration

(ALG-3)Estimated mean concentration over 2.5 km2 area for

estimating airborne source term and ingestion intakes

90Sr 7.1 × 105 1.2 × 105

137Cs 3 × 104 3.5 × 103

239+240Pu 1.4 × 106 7 × 103

241Am 2.4 × 104 6 × 103

48

II.1.4. Inhalation doses in the town of Reggane

The town of Reggane is approximately 50 kmnorth-east of the test site. If, taking account of thedistance to Reggane, the nominal 2.5 km2 contami-nated area is considered as a point source giving riseto a ground level release, the air concentration atthe distance of Reggane for a wind with a bearing inthe direction of the town would be less than threeorders of magnitude below that at a distance of 1 kmfrom the nominal site, ignoring deposition (see fig. 3in Ref. [13]). During windy conditions the dustloading in the lower atmosphere is in equilibrium,with resuspension and deposition rates roughlyequal, so that in higher winds deposition rates arealso higher. The inhalation rate in Reggane ofmaterial from the active zone is then less than0.023 mg/d, neglecting deposition and with winddirection fixed. Taking account of deposition in highdust conditions will lead to airborne concentrationsat the distance of Reggane being reduced by at leasta further order of magnitude. If the wind is in thedirection of Reggane for 25% of the time, an upperbound to annual 239+240Pu inhalation intake is thenof the order of 2.3 × 10–6 (g/d) × 0.25 × 120 (Bq/g) ×365 (d) = 0.02 Bq. The derivation of the annual dosearising from inhalation needs to take account of therespirable fraction of the inhaled activity. This islikely to differ from that near the test site because ofdifferential settling, but on the basis of the very

small measured respirable activity fraction at theGerboise Blanche site, the resulting doses areclearly negligible (far below 1 mSv/a).

II.2. IN EKKER — TAOURIRT TAN AFELLA

The principal exposure pathways at TaourirtTan Afella are:

— External radiation, particularly in the vicinityof ejected lava;

— Inhalation of dust;— Ingestion of dust;— Ingestion of water containing leached

material; — Ingestion of products (milk, meat) from

animals that intermittently graze in the area.

II.2.1. External exposure

External exposure rates are elevated fromdeposition following airborne releases at the time ofthe tests (and from lava ejecta in the case of the E2site) in the vicinity of both the E2 and the E3galleries. The deposition from the E2 site is themore widespread. Some smaller ejected pieces weredispersed for several hundred metres at the time ofthe detonation, and others have been subsequentlytransported by water in occasional rainstorms. Bothover a small area at the E3 site and outside the

TABLE 19. DOSE COEFFICIENTS FOR INHALATION AND INGESTION

NuclideLung

retentiontypea

f1 b Committed effective dose per unit intake

(Sv/Bq)

Inhalation90Sr F 0.3 2.4 × 10–8

137Cs F 1.0 4.8 × 10–9

239+240Pu S 1.0 × 10–5 1.5 × 10–5

241Am M 5.0 × 10–4 3.9 × 10–5

Ingestion90Sr 0.3 2.8 × 10–8

137Cs 1.0 1.3 × 10–8

239+240Pu 1.0 × 10–5 9.0 × 10–9

241Am 5.0 × 10–4 2.0 × 10–7

a F: fast; M: medium; S: slow.b f1: gut transfer factor.

49

original fence constructed by the French authoritiesat the E2 site, dose rates range up to about240 nGy/h above background. The upper bound tothe effective dose above background (about80 nGy/h) from external radiation received by anomadic herder remaining outside the originalfence would then be about 40 mSv/a. (This assumes afactor of 0.7 to relate dose to air or ambient doseequivalent to effective dose for 0.66 MeVradiation.)

Occasional visits within the original fencecould give rise to higher exposures, particularly ifthe bulk lava areas were walked on. It may benoted, however, that these lava areas are generallyquite steeply sloping and support no vegetation, sothat the only reason for people to venture into thearea (which has a warning monument) is curiosityor the desire to scavenge materials. In an extremecase, if some persons spent as much as two workingdays (of eight hours each) in an area immediatelyadjacent to or on the lava masses where the doserates were 100 mGy/h, an upper bound to effectivedoses received from such an exposure scenariowould be about 1.1 mSv/a.

II.2.2. Inhalation of dust

Measured soil concentrations of plutoniumare very much lower than at the Reggane site (by afactor of 103 less, comparing the ALG-18 resultswith Table 18), and for similar occupancy scenarios,inhalation doses are expected to be negligible(<1 mSv/a). Further, the presence of the mountainmay affect wind directions such that high windsallowing direct transport from the site do not occur.

II.2.3. Ingestion of soil

Ingestion of soil on foodstuffs handled industy conditions might contribute small doses to

nomadic people in the area. As noted, measuredsurface soil activities of plutonium are very muchlower than the peak levels at the Reggane test site,and 137Cs and 90Sr concentrations are comparable tothe mean values in the areas of elevated concentra-tions at Reggane. If again a daily intake of 10 g isassumed, which may be extreme for this location,then for the equivalent of ten days spent in the area,annual doses of about 10 mSv are estimated(Table 20).

II.2.4. Ingestion of water

Doses arising from consumption of well waterat In Ekker were anticipated to be small, with 90Srexpected to have the greatest mobility of thepotentially contributing radionuclides. For a personconsuming 1000 litres of water per year from thewell the doses incurred are:

1000(CCs × 1.3 × 10–8 + CSr × 2.8 × 10–8) × 103

mSv/a

where CCs and CSr are the 137Cs and 90Sr concentra-tions in Bq/L. The mobility of strontium in soils isgenerally greater than that of caesium. For anannual dose of 1 mSv, a 90Sr concentration of about35 Bq/L would be required. The measured concen-trations are below the limits of detection (for 90Sr <0.02 Bq/L), indicating that the current doses arisingfrom ingestion of anthropogenic radionuclides inwater are negligible.

In the longer term, the water concentrationscould increase through continued leaching. Ifconcentrations in water had been readilymeasurable, it would have been useful to extractwater samples at different distances along thewatercourse to assess the variation in concentrationwith distance, and in conjunction with these

TABLE 20. ANNUAL DOSES FROM INGESTION OF DUST IN THE VICINITY OF THE E2 TUNNEL

NuclideSoil concentration

(Bq/kg)

Committed effective dose equivalent

(mSv/a)

90Sr 2 × 103 5.6137Cs 3.5 × 103 4.6239+240Pu 5 × 101 <1

All 10

50

measurements also to determine the distributioncoefficient for strontium and caesium in the soils.These values would have aided in the prediction ofpossible future trends in water concentrations.However, taking account of common values fordistribution coefficients in soils for the nuclides ofinterest and the probable very low rate of leachingfrom the lava, the measured concentrations in thedry watercourse soils are sufficiently low topreclude the possibility of significant concentrationsarising in downstream wells.

II.2.5. Ingestion of animal products

The sparse vegetation in the region is grazedby camels and other domestic species (goats,donkeys). The vegetation is sufficiently sparse forthe animals to be almost constantly on the move,spending at most a few days in one area. Distancesto available water sources also dictate animalmovements, and animals would not normally beable to stay in the E2 and E3 areas for more than aday or two. Grazing livestock could ingest residualradionuclides incorporated in plants through rootuptake, and deposited on plants in dust. Visualinspection suggested that deposited dust maydominate intakes and the concentrations in this dustwould reflect the surrounding surface soil concen-trations. Dietary intake of livestock is related tobody mass. For the dusty vegetation conditionsobserved, it is postulated that an animal mightingest 1–2 kg per day of soil per 500 kg of body mass(which can be compared with a value of 0.5 kg/d forcattle used in a modelling program [14]).

The 137Cs soil concentration corresponding to240 nGy/h, taking account of background, is about0.4 MBq/m2. If this activity is distributed over a soildepth of 5 cm (say 100 g/cm2), the soil concentrationis about 4 kBq/kg, in good agreement withmeasured values. An upper bound to livestockintake for ten days of grazing in the area is then40 kBq per 500 kg body mass. Using an ingestion to

meat transfer factor of 0.5 for 137Cs [15], the concen-tration in animal muscle would be similar to thatarising from natural 40K in the body at about120 Bq/kg. This is well below the Codex Alimen-tarius value of 1000 Bq/kg for food moving in inter-national trade [16], so that the upper bound for doseto persons eating meat from animals slaughteredimmediately after grazing in the area is unlikely tobe more than a few microsieverts. (A butcheredanimal is likely to be eaten by a large number ofpeople, so that particular individuals are not likelyto have more than a few meals from any specificanimal. Five meals of 200 g servings would result ina maximum likely intake of about 120 Bq of 137Cs,giving rise to an effective dose of <2 mSv.) A smallercontribution to dose would arise from 90Sr ingestion,but the concentration in soil is lower and thetransfer factor to muscle is almost two orders ofmagnitude lower than for caesium. The soil to meattransfer factors shown in Table 21 are based onvalues derived from sheep, which are morerestrictive (i.e. are larger values) than those forcattle. They are derived for continuous intake andequilibrium conditions rather than for shortterm ingestion over a few days. The transientconcentration in meat is therefore likely to beoverestimated.

Consumption of milk from grazing livestock isalso not likely to be a significant contributor todose. If an infant 1–2 years old consumed 0.5 L/d ofmilk from an animal that had ingested 80 kBq of137Cs, on the basis of the transfer factor in Table 17in Appendix I the cumulated activity intake fromthe milk would be 200 Bq, and applying an effectivedose per unit intake factor from the InternationalBasic Safety Standards for Protection againstIonizing Radiation and for the Safety of RadiationSources (BSS) [3] for members of the public whoare 1–2 years old, this results in a dose of about2 mSv. Adding the contribution from 90Sr implies atotal dose of about 6 mSv for this hypothetical milkconsumption. These values could be doubled if the

TABLE 21. TRANSFER FACTORS FROM ANIMAL INTAKE TO ANIMALPRODUCTS [14]

Nuclide

Concentration in foodon the basis of animal intake

Meat (Bq/kg)/(Bq/d) Milk (Bq/L)/(Bq/d)

90Sr 3 × 10–3 2 × 10–3

137Cs 5 × 10–1 5 × 10–3

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solids content of the milk of desert livestock werenotably greater than that of cows.

II.3. IN EKKER — ADRAR TIKERTINE

The principal exposure pathways at AdrarTikertine are inhalation and ingestion (of soil).

The data supplied by the French authoritiessuggest that plutonium concentrations at 200 mfrom the tower position in the downwind directionare about 37 kBq/m2, corresponding to about4 kBq/kg in surface (0.5 cm depth) soil, anddecreasing with increasing distance. There has beenboth wind and water transport of surface soils andparticles during the intervening years since the testswere performed. It is assumed that nomads whograze livestock spend a total of three days per yearin the area, which is in general much more remote

than In Ekker. The measurement results indicatemuch lower current concentrations of 239+240Pu thanthose that have been estimated from historic data.

II.3.1. Inhalation and ingestion of dust

Historic concentrations appear to have beensubstantially reduced by wind and water transport.However, even if the historical concentrations wereapplicable, doses arising from ingestion andinhalation of dust would be about two orders ofmagnitude lower than those derived for theReggane desert, so that for both intake routes,doses of less than 1 mSv/a would apply. Themeasurements also demonstrate that the activityconcentrations of anthropogenic radionuclides inrespirable particles were at or below detectionlimits.

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Appendix III

RADIOLOGICAL CONCEPTS IN THE CONTEXT OF NUCLEAR WEAPON TESTING

This appendix provides the context for theassessment of the radiological conditions at theAlgerian nuclear test sites by introducing the mostimportant radiological concepts, quantities andunits used in the report. It briefly describes thehealth effects that can be caused by exposure toionizing radiation.5

III.1. RADIOLOGICAL QUANTITIES AND UNITS

Radiation is the transport of energy throughspace. In traversing material, radiated energy isabsorbed. In the case of ionizing radiation, theabsorption process consists in the removal ofelectrons from the atoms, producing ions. Ionizingradiation (hereafter referred to as radiation) isimmanent in the universe. It originates from thecosmos. It is also produced in manufactured devicessuch as X ray tubes, and it results ubiquitously fromthe disintegration of radioactive atoms of matter (orradionuclides) — the phenomenon that is calledradioactivity. Radionuclides occur naturally or theymay be produced artificially, for instance in nuclearexplosions such as those with which this publicationis concerned. As the radionuclides disintegrate, theyoften transform into other radionuclides, but theyfinally transform into stable elements. The timerequired for the transformation of one half of theatoms of the radionuclide concerned is a constantvalue and is termed the half-life of the radionuclide.

The BSS [3] have adopted the internationalsystem of radiation quantities and unitsrecommended by the International Commission onRadiation Units and Measurements (ICRU). Themain physical quantities of the system are theactivity, or rate of nuclear transformation of radio-nuclides emitting radiation, and the absorbed dose,or energy absorbed per unit mass of matter from theradiation to which it is exposed. Thus:

(a) The activity of a radioactive material is thenumber of nuclear disintegrations of radionu-clides within that material per unit time, theunit of activity being the reciprocal second,termed the becquerel (Bq)6;

(b) The absorbed dose of radiation is the energyimparted per unit mass of material, the unit ofabsorbed dose being the joule per kilogram,termed the gray (Gy).

Although the absorbed dose is the basicphysical dosimetric quantity, it is not entirely satis-factory for radiation protection purposes since theeffectiveness of radiation in damaging human tissuediffers for different types of ionizing radiation.Consequently the absorbed dose averaged over atissue or organ can be multiplied by a radiationweighting factor to take account of the effectivenessof the given type of radiation in inducing healtheffects. The resulting quantity is termed theequivalent dose.

The quantity equivalent dose is used whenindividual organs or tissues are irradiated.However, the likelihood of injurious late effectsowing to a given equivalent dose differs fordifferent organs and tissues. Consequently, whenpart of the body or the whole body is irradiated, theequivalent dose to each organ and tissue can bemultiplied by a tissue weighting factor to takeaccount of the differing radiosensitivities ofdifferent organs of the body. The sum total of suchweighted equivalent doses for all exposed tissues inan individual is termed the effective dose. Theeffective dose was derived to provide a metric ofradiation exposure that would be better correlatedwith the risk of developing all cancer types.

The unit of equivalent dose and that ofeffective dose are the same as that of absorbed dose,namely the joule per kilogram (or gray), but the

5 This information has been derived from the Inter-national Basic Safety Standards for Protection againstIonizing Radiation and for the Safety of RadiationSources (commonly known as the Basic Safety Standards(BSS)) [3] and the latest UNSCEAR reports [4, 5].

6 Since the becquerel is a unit expressing a verysmall activity, the following multiples are commonly used:1000 Bq or kilobecquerel (kBq); 1 million Bq or mega-becquerel (MBq); 1 ¥ 109 Bq or gigabecquerel (GBq);1 ¥ 1012 Bq or terabecquerel (TBq); 1 ¥ 1015 Bq or peta-becquerel (PBq); 1 ¥ 1018 Bq or exabecquerel (Ebq).

53

term sievert (Sv) is the special name applied to theequivalent and effective dose. This reportcommonly uses the millisievert (mSv), a subdivisionof the sievert that is equal to a thousandth of asievert. (For the purpose of comparison, the averageannual individual effective dose that the world’spopulation incurs as a result of exposure to cosmicrays and radiation arising from naturally radioactivematerials in the biosphere is about 2.4 mSv.)

In general, unless otherwise stated, the termdose is used in this report to mean effective dosewhen it refers to the whole body or equivalent dosewhen it refers to body organs.

When radionuclides are taken into organs ofthe human body, the resulting dose is received bythe exposed individual throughout the period oftime during which their activity continues in thebody. The committed dose is the total dosedelivered during this period of time, but is assignedto the year of intake. Dose assessments in thisreport are based on the committed dose fromintake.

III.2. RADIOLOGICAL RELEASES DUE TO TESTING OF NUCLEAR WEAPONS

III.2.1. Above ground testing and the generation of radioactive fallout

The radioactive debris from an above ground(either surface or atmospheric) nuclear test ispartitioned between the local ground or watersurface and the tropospheric and stratosphericregions of the atmosphere, depending on the type oftest, location and yield. In general, the higher theexplosive yield of the test, the higher the altitude towhich the debris is ejected. The subsequent precipi-tation or falling out of the debris is termed localfallout when the debris is locally dispersed, andtropospheric fallout and stratospheric fallout whenit is regionally or globally dispersed.

Local fallout can include as much as 50% ofthe total activity produced and/or released fromsurface tests and usually includes a large fraction ofthe activity in the form of relatively large particleswhich are deposited within about 100 km of the testsite.

Tropospheric fallout consists of smalleraerosols which are not carried across thetropopause after the explosion and which depositwith a mean residence time of up to 30 days. Duringthis period the debris becomes dispersed, althoughnot well mixed, in the latitude band of the test site

and follows trajectory directions governed by windpatterns. From the viewpoint of human exposures,tropospheric fallout is important for nuclides with ahalf-life of a few days to two months, such as 131I,140Ba and 89Sr.

Stratospheric fallout, which comprises a largepart of the total worldwide fallout, is due to thoseparticles that are carried to the stratosphere andlater give rise to global fallout, the major part ofwhich is deposited within the hemisphere of the testsite. Stratospheric fallout accounts for most of theworldwide deposited residues consisting of longlived fission products. Exposure of humans tofallout activity results from internal irradiation (as aresult of inhalation of activity in surface air andingestion of contaminated foodstuffs) and fromexternal irradiation from activity present in surfaceair or deposited on the ground.

III.2.2. Underground testing and releases of radioactive material to the environment

Underground nuclear tests have beenconducted at various locations worldwide, primarilyby the United States of America and the formerSoviet Union but also by France in Algeria. Theplacement of the nuclear devices within the earthdefines the specific type of underground test [17]:

— Tunnel: exploded at the end of a longhorizontal hole mined into a mountain ormesa (plateau) in a way that places the burstpoint deep within the earth;

— Shaft: exploded at the end of a drilled ormined vertical hole;

— Crater: placed shallow enough undergroundto produce a throw-out of the earth whenexploded.

When a nuclear device is exploded under-ground, a sphere of extremely hot, high pressuregases (a temperature of about a million degrees anda pressure of several million atmospheres arereached with a few microseconds), includingvaporized weapon residues and rock, is formed [18].The rapid expansion of the gas initiates a shockwave that travels in all directions away from theburst point. The shock (or compression) wave istypically reflected back from the ground surfacetowards the detonation, and depending on thedepth of the explosion, the returning shock wavemay intersect with the expanding gas bubble while itis still growing. In that case, the upper ground layers,

54

having already experienced the transmission anddestruction of the shock wave, provide lessresistance to the expanding gas bubble so that thereis a relative degree of acceleration of the expandinggas towards the surface.

While many underground tests are intended tocontain the generated radioactive material, releasesto the environment do occur from shallowunderground bursts as well as from more deeplyplaced devices when the ground surface is breachedby cracks or when accidental circumstances, such asin the case of one of the tests at the Taourirt TanAfella mountain, result in a tunnel not properlyclosing before the gas bubble reaches the exit.

Unlike the case of above ground oratmospheric explosions where bomb debris andvaporized soil are ejected high into the atmosphere,releases from underground tests typically either arecontained underground or vent to the atmosphereand are accompanied by massive amounts of soiland rock (not vaporized) that are ejected only to afew hundreds of metres. If the release is directlyabove the explosion, much of the ejected material ishurled upwards and normally falls back into acrater. In rare circumstances, such as at the TaourirtTan Afella mountain, molten rock and hot gases areejected horizontally from the tunnel entrance andthe ejected material that is deposited appears as along stream of solidified lava.

III.3. HEALTH EFFECTS OF RADIATION EXPOSURE

It has been recognized since the time of thefirst studies of X rays and radioactive minerals thatexposure to radiation at high levels can cause acutedamage to the tissues of the human body. If thisdamage is extremely severe, it can lead to death. Inaddition, long term epidemiological studies of bothhuman and animal populations exposed toradiation, particularly the survivors of the atomicbombing of Hiroshima and Nagasaki in Japan in1945, have demonstrated that exposure to radiationalso has a potential for the delayed (or late)induction of malignancies and, plausibly, forhereditary effects.

III.3.1. Early effects

Exposure to very high radiation doses cancause effects such as nausea, reddening of the skinor, in severe cases, more acute syndromes that are

clinically expressed in exposed individuals within ashort period of time after the exposure. Such effectsare called deterministic effects because they arecertain (predetermined) to occur if the dose exceedsa threshold level. Deterministic effects are the resultof various processes, mainly cell death and impairedcell division, caused by exposure to radiation. Ifthese processes are extensive enough, they canimpair the function of the exposed tissue. Thehigher the dose is above the threshold for theoccurrence of a particular deterministic effect in anexposed individual, the more severe is the effect.The threshold dose levels depend on the type ofeffect, the organ affected and the duration ofexposure. For doses delivered in a short period oftime, deterministic effects are generally notobserved below equivalent doses of 1000 mSv.Death due to acute radiation syndrome may occurat an effective dose of several tens of thousands ofmillisieverts.

III.3.2. Late effects

Radiation exposure can also induce effectssuch as malignancies, which are expressed after along latency period of about four to five years in theshortest instances or of many decades in other cases.A complete understanding of the processes whichlead to cancer development following radiationexposure is not available, yet there is a significantbody of knowledge which relates the likelihood ofcancers arising in different organs to various levelsof exposure. In the case of cancer, it is thelikelihood, rather than the severity of the disease,that is increased by radiation exposure. For mostorgans, the likelihood or risk increases linearly withincreasing radiation dose and is often assumed notto have a threshold. In addition, experimentalstudies in animals and plants have shown hereditaryeffects from radiation. Although hereditary effectshave not been observed in humans, it is consideredprudent for the purposes of setting standards toassume that they do occur. These radiation inducedmalignancies and hereditary effects are termedstochastic effects because of their probabilisticnature. The induction of stochastic effects isassumed to take place over the entire range ofdoses, without a threshold level. Under certainconditions, primarily of relatively high doses and/orlarge numbers of people exposed, stochastic effectsmay be epidemiologically detectable in the exposedpopulation as an increase in their incidence.

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Appendix IV

RADIATION PROTECTION CRITERIA

IV.1. GENERAL CONSIDERATIONS

The International Basic Safety Standards forProtection against Ionizing Radiation and for theSafety of Radiation Sources (BSS) [3] are radiationsafety standards developed by consensus throughinternational cooperation and participation by theFood and Agriculture Organization of the UnitedNations (FAO), the International Atomic EnergyAgency (IAEA), the International Labour Organi-zation (ILO), the OECD Nuclear Energy Agency,the Pan American Health Organization (PAHO)and the World Health Organization (WHO). Thedevelopment of these standards relied on scientificinformation on radiation levels worldwide and onrelated health effects compiled globally by theUnited Nations Scientific Committee on the Effectsof Atomic Radiation (UNSCEAR), a body set upby the United Nations General Assembly in 1955.The latest report of UNSCEAR to the UnitedNations General Assembly was issued in 1993 [4]and a revised report was published in 2000 [5]. Thesafety criteria in the BSS are based primarily on therecommendations of the International Commissionon Radiological Protection (ICRP), a non-govern-mental scientific organization founded in 1928 toestablish basic principles and recommendations forradiation protection. The most recent recommenda-tions of the ICRP were issued in 2000 [19].

International radiation safety standards suchas the BSS [3] are intended to provide requirementson safety for the national regulation of the peaceful,beneficial uses of radiation and nuclear energy only.The practice of nuclear weapon testing wastherefore not considered during their estab-lishment. However, the BSS do consider chronicexposure situations.

The BSS apply to two classes of societalactivities involving radiation exposure. These arepractices and interventions. Practices are anyhuman activity that introduces additional sources ofexposure or exposure pathways so as to increase theexposure or the likelihood of exposure of people orthe number of people exposed. Interventions areactivities intended to reduce or avert exposure orthe likelihood of exposure to sources which are notpart of a controlled practice or which are out of

control as a consequence of an accident. In thelatter case it is feasible and reasonable to takeremedial measures to reduce the doses to someextent.

In general, practices are not authorized unlessthe practice produces sufficient benefit to theexposed individuals or to society to offset theradiation harm that it might cause. The BSS requirethat additional doses above background levels thatare expected to be delivered by the introduction orproposed continuation of a practice be restricted.The restriction is intended to be applied prospec-tively to constrain the forecast extra doses.

With respect to interventions, the BSS statethat such actions are justified only if they areexpected to achieve more good than harm, with dueregard to health, social and economic factors. If thedose levels approach or are expected to approachspecified levels, protective actions or remedialactions will be justified under almost anycircumstances.

Two types of intervention situation arerecognized in the BSS. The first relates toemergency exposure situations, such as in theimmediate aftermath of a radiological accident,requiring protective actions to reduce or avert thetemporary (short term) doses caused by thesituation. The second relates to chronic exposuresituations where long term environmental radiationlevels exist that lead to continuing exposure of aresident population, usually at a relatively low doserate, requiring remedial actions to reduce theexposure rate.

IV.2. GENERIC INTERVENTION LEVELS

The underlying policy of intervention as setout in the BSS [3] is that the decision on whether ornot intervention should be contemplated and howmuch the existing dose levels should be reduceddepends on the circumstances of each individualcase. In order to determine whether and when anintervention should be undertaken, interventionlevels are established. These levels should bedetermined in terms of the doses expected to beaverted by a specific remedial action intended toprotect people from exposure. The intervention

56

levels are usually expressed in quantities derivedfrom the avertable dose. In the case of chronicexposure situations these derived levels are usuallyreferred to as action levels.

Intervention action levels are expected to beestablished ad hoc, i.e. on a case by case basis, andtailored to the specific circumstance of the inter-vention situation. However, there has been arecognized need for simple and internationallyagreed guidance on generic levels applicable to anyintervention situation, particularly in cases ofchronic exposure.

The BSS establish that if doses approachlevels at which the likelihood of deleterious healtheffects is very high, intervention would be expectedto be undertaken under almost any circumstances.These quasi-mandatory levels, which are set up inthe BSS, depend on the organ exposed, and forchronic exposure situations vary from a level ofequivalent dose of 100 mSv/a for the lens of the eyeto 400 mSv/a for the bone marrow (Table 22).

From the established levels of equivalentdoses and on the basis of recommended weightingfactors to take account of the radiosensitivity of therelevant organs, it could be construed that inter-vention would not be expected to be undertakenunder any circumstances unless the annual effectivedose exceeds several tens of millisieverts. At lowerdoses, proposed interventions need to be justifiedon a case by case basis.

IV.3. GUIDELINES THAT MAY BE APPLICABLE TO CHRONIC EXPOSURE SITUATIONS

Temporary relocation and permanent reset-tlement are among the more extreme protectivemeasures available to control exposures to thepublic in the event of a radiological emergency.Table 23 shows the generic levels established in the

BSS for temporary relocation and permanentresettlement.

Temporary relocation is used to mean theorganized and deliberate removal of people fromthe area affected during an extended, but limited,period of time. As the situation is temporary, thegeneric guidelines to initiate and terminaterelocation refer to relatively high levels of dose: 30and 10 mSv per month, respectively.

Permanent resettlement is the term used for thedeliberate removal of people from the area with noexpectation of return. Permanent resettlementshould, according to the BSS, be considered if thelifetime dose over 70 years cannot be reduced byother means and is projected to exceed 1 Sv. Whendoses are below this level, permanent resettlementis unlikely to be necessary.

The BSS establish that if there is no shortageof food and there are no other compelling social oreconomic factors, action levels for the withdrawaland substitution of specific supplies of food anddrinking water which have been contaminated withradioactive substances should be based on theguidelines for foodstuffs in international tradeestablished by the Codex Alimentarius Commission(CAC) [16]. These are included in the BSS [3] asrecommended generic action levels for activity infoodstuffs. The levels are limited to radionuclidesusually considered relevant to emergency exposuresituations. All the relevant radionuclides for theprevailing situation at the nuclear test sites inAlgeria are included (Table 24).

Depending on the annual ‘food basket’ [16] ofthe population, the doses resulting from the CAClevels will vary, but using the FAO figure for totalfood consumption of 550 kg per year (not includingdrinking water), the consumption of food of whichevery component has activity concentrations at theCAC action levels would result in a maximumannual committed effective dose of up to about10 mSv. This figure assumes that the food basket iscontaminated to the full CAC values for the wholeyear.

TABLE 22. LEVELS OF EQUIVALENT DOSERATE AT WHICH INTERVENTION ISEXPECTED TO BE UNDERTAKEN UNDERANY CIRCUMSTANCES

Organ or tissue Equivalent dose rate(mSv/a)

Gonads 200

Lens of the eye 100

Bone marrow 400

TABLE 23. GENERIC LEVELS FOR TEMPO-RARY RELOCATION AND PERMANENTRESETTLEMENT

Intervention Initiate Terminate

Temporary relocation 30 mSv/month 10 mSv/month

Permanent resettlement

Lifetime dose > 1 Sv

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IV.4. REFERENCE FOR COMPARISON: DOSES DUE TO NATURAL BACKGROUND RADIATION

The worldwide individual average annual doseincurred among the global population owing toradiation from natural sources is estimated to be2.4 mSv [5, 19], of which about half is mainly due tocosmic and terrestrial background radiation andhalf is due to exposure to 222Rn. There is, however, alarge variability in the annual effective dosesresulting from natural sources. It is common to findlarge regions with exposures elevated by up to anorder of magnitude and smaller regions with evenhigher levels. Table 25 indicates average typical andelevated values of annual effective doses to adultsfrom natural sources. The elevated values are repre-sentative of large regions, but much higher atypicalvalues may occur locally.

The effective dose rate due to cosmicradiation depends on the height above sea level and

the latitude. The annual effective doses in areas ofhigh exposure (locations at higher elevations) areabout five times the average. The terrestrialeffective dose rate depends on the local geology,with a high level typically being about ten times theaverage; the effective dose to communities livingnear some types of mineral sand may be up to about100 times the average. The effective dose fromradon decay products depends on the local geologyand on housing construction and use, with the dosein some regions being about ten times the average.Local geology and the type and ventilation of somehouses may combine to give effective dose ratesfrom radon decay products of several hundred timesthe average.

The range of the worldwide annual effectivedose from natural sources would be 1–20 mSv, withvalues in some regions of the order of 30–50 mSvand high levels of above 100 mSv, although theglobal average annual effective dose due to naturalbackground radiation is of the order of a fewmillisieverts.

IV.5. GENERIC GUIDANCE FOR REHABILITATION OF AREAS OF CHRONIC EXPOSURE

From the earlier discussion, it appears that anannual effective dose of up to about 10 mSv can beused as a generic guideline for action levels forconsidering protective remedial actions to rehabil-itate areas subject to chronic exposure, such as theareas with residual radionuclides from nuclearweapon testing in Algeria. For doses below theguidance action levels, the situation could, after dueconsideration, generally be taken as not beinghazardous above accepted norms.

It is emphasized, however, that this genericallyacceptable action level of annual dose does notimply that below such a level it is never worth whilereducing the radiation exposure. If it is justified onradiological grounds, intervention for purposes ofradiological protection should always beundertaken, and the form, scale and duration of theintervention would be determined by a process ofoptimization of protection.

One point of confusion is whether it is thedoses due to the residual radionuclides or the totaldose (including doses due to the naturalbackground radiation) that should be comparedwith the action level. In this report both dose valuesare presented.

TABLE 24. GENERIC ACTION LEVELS (kBq/kg) FOR FOODSTUFFS

RadionuclideFoods destined for

general consumption

Milk, infant food and

drinking water

134Cs, 137Cs, 103Ru, 106Ru, 89Sr

1 1

131I 0.190Sr 0.1241Am, 238Pu, 239Pu 0.01 0.001

TABLE 25. ANNUAL EFFECTIVE DOSES(mSv) TO ADULTS FROM NATURALSOURCES

Worldwide average annual effective dose

Typical range

External dose

Cosmic rays 0.4 0.3–1.0

Terrestrial gamma rays 0.5 0.3–0.6

Internal dose

Inhalation 1.2 0.2–10

Ingestion 0.3 0.2–0.8

Total 2.4 1–10

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