SPECIAL REPORT

Radiological assessment:Waste disposal in the Arctic Seas

Summary of results from an IAEA-supported study on the radiologi-cal impact of high-level radioactive waste dumping in the Arctic Seas

Almost five years ago, in 1992, internationalattention was focused on news reports that theformer Soviet Union had, for over threedecades, dumped radioactive wastes in the shal-low waters of the Arctic Seas. The news causedwidespread concern, especially in countrieswith Arctic coastlines.

At the global level, the IAEA responded byproposing an international study to assess thehealth and environmental implications of thedumping. The proposal received support fromthe Fifteenth Consultative Meeting of theContracting Parties to the Convention on thePrevention of Marine Pollution by Dumping ofWastes and Other Matter (London Convention1972), which is under the auspices of theInternational Maritime Organization (IMO) inLondon. The Consultative Meeting requestedthat the study include consideration of possibleremedial actions, such as the retrieval of thewastes for land storage.

Shortly thereafter, in 1993, the IAEAlaunched the International Arctic SeasAssessment Project (IASAP).* Its main objec-tives were to assess the risks to human healthand to the environment associated with theradioactive wastes dumped in the Kara andBarents Seas; and to examine possible remedialactions related to the dumped wastes and toadvise on whether they are necessary and justi-fied. The study, which involved more than 50experts from 14 countries and was under thedirection of an International Advisory Group,concluded in late 1996. Partially supported by

This article is based on the Executive Summary of theIASAP study which was prepared by the project's AdvisoryGroup. Ms. K.-L. Sjoblom of the IAEA's Waste SafetySection in the IAEA Division of Radiation and WasteSafety served as IASAP project officer..

extrabudgetary funding from the United States,the project was co-ordinated with the work ofthe Norwegian-Russian Expert Group forInvestigation of Radioactive Contamination inthe Northern Areas. This article summarizes theresults and conclusions of IASAP, drawingupon the Executive Summary of the final reportof the study.

What the study examined

Through a co-ordinated research pro-gramme, technical contracts, consultancies, andother mechanisms, the study brought together awide range of expertise in various disciplines.The adopted approach specifically focused on:• Examination of the current radiological situ-ation in Arctic waters to assess evidence forreleases from the dumped waste;• Prediction of potential future releases fromthe dumped wastes concentrating on the solidhigh level waste objects which contain themajority of the radionuclide inventory of thewastes;• Modelling of environmental transport ofreleased nuclides and assessing the associatedradiological impact on man and biota;• Examination of the feasibility, costs, andbenefits of possible remedial measures appliedto a selected high-level waste object.

The total amount of radioactive wastedumped in Arctic Seas was estimated to beapproximately 90 PBq (90 x 1015 Bq) at thetime of dumping, based on information con-

*The background and early progress of the IASAP studywas described in an article by K.-L. Sjoblom and G.S.Linsley in the IAEA Bulletin, Vol. 37, No. 2 (1995).

IAEA BULLETIN, 39/1/1997 21

SPECIAL REPORT

tained in the "White Book of the President ofRussia" (Facts and Problems Related toRadioactive Waste Disposal in the SeasAdjacent to the Territory of the RussianFederation, 1993). The dumped items includedsix nuclear submarine reactors containing spentfuel; a shielding assembly from an icebreakerreactor containing spent fuel; ten nuclear reac-tors without fuel; and solid and liquid low levelwaste. Of the total estimated inventory, 89 PBqwas contained in high-level wastes comprisingreactors with and without spent fuel. The solidwastes, including the reactors mentioned above,were dumped in the Kara Sea, mainly in theshallow fjords of Novaya Zemlya, where thedepths of the dumping sites range from 12 to135 meters and in the Novaya Zemlya Trough atdepths of up to 380 meters. Liquid low-levelwastes were released in the open Barents andKara Seas.

Additional information regarding the natureof the wastes was obtained through technicalcontracts placed in Russian institutes. There are,however, certain important gaps in the availableinformation. For example, not all of the dumpedhigh-level wastes referred to in RussianFederation documents have been located orunambiguously identified. Furthermore, someinformation related, for example, to the con-struction of the dumped submarine reactors andtheir fuel type remained classified. Thus, theconclusions of the IASAP study are valid onlyin the context of the information publicly avail-able at the time it was completed.

The results of the IASAP study will be pub-lished in the report Assessment of the Impact ofRadioactive Waste Dumping in the Arctic Seas— Report of the International Arctic SeasAssessment Project (IASAP). In addition,reports containing the findings of three differentworking groups will be published separately: (i)the environmental and radiological descriptionof the Arctic Seas; (ii) the evaluation of thesource term; and (iii) modelling and doseassessment. The study's Executive Summaryhas been provided to the Contracting Parties tothe London Convention 1972 as agreed at theFifteenth Consultative Meeting.

Current radiological situation

The current radiological situation in theArctic Seas was examined by analyzing infor-mation acquired during a series of jointNorwegian-Russian cruises and other interna-

tional expeditions to the Kara Sea. In addition,oceanographic and radiogeochemical surveys,many of them related to the IASAP study, pro-vided new information on the physical, chemi-cal, radiochemical, and biological conditionsand processes in the Arctic Seas.* The openKara Sea is relatively uncontamiiiated com-pared with some other marine areas, the maincontributors to its artificial radionuclide contentbeing direct atmospheric deposition and catch-ment runoff of global fallout from nuclearweapon tests, discharges from reprocessingplants in western Europe, and fallout from theChernobyl accident.

The measurements of environmental materi-als suggest that annual individual doses fromartificial radionuclides in the Kara and BarentsSeas are only in the range of 1 to 20 microsiev-erts. In two of the fjords where both high- andlow-level wastes were dumped, elevated levelsof radionuclides were detected in sedimentswithin a few meters of the low-level waste con-tainers, suggesting that the containers haveleaked. However, these leakages have not led toa measurable increase of radionuclides in theouter parts of the fjords or in the open Kara Sea.At the present time, therefore, the dumpedwastes have a negligible radiological impact.

Future radiological situation

The assessment of the potential risks posedby possible future releases from the dumpedwastes focused on the high-level waste objectscontaining the majority of the radioactive wasteinventory. Release rates from these wastes wereestimated and the corresponding radiation dosesto man and biota were assessed using mathe-matical models for radionuclide transferthrough the environment.

Source inventories and release rates. Thecharacteristics of the dumped reactors and theiroperating histories were examined in consider-able detail. This was done in order to provideappropriate release rate scenarios that can beused as input terms to the modelling of transportand exposure pathways leading to exposureestimates for humans and biota. This informa-tion, based on reactor operating histories andcalculated neutron spectra, provided estimatesof fission product, activation product, and

*For more information on Arctic environmental studies, seethe article by P. Povinec, I. Osvath, and M. Baxter in theIAEA Bulletin Vol. 37, No. 2 (1995).

22 IAEA BULLETIN, 39/1/1997

SPECIAL REPORT

The Arctic Ocean,and the Kara andBarents Seas

The map at right shows the high-level waste dump sites on the east coast of Novaya Zemlya; the map at left shows themain sea currents relevant to the radiological assessment of the Arctic Seas, (IAEA-MEL)

yeaM

>10 >50 >100 Bq/m3

Photo: Marine scientists take water samples from the Arctic Seas. (IAEA-MEL) Graphs:Shown at left are predicted caesium-137 concentrations in seawater in the first six yearsafter an instantaneous unit release from all dumping sites. These types of predictionswere used for identification of potentially exposed populations. (Ingo Harms/IAEA-MEL)

IAEA BULLETIN, 39/1/1997 23

SPECIAL REPORT

Examples of pre-dicted release

rates

1013

1012

10"

1010

109

a, 10e

S 107

Iir 106

105

10"

103

1021800 2000

actinide inventories of the dumped reactors andfuel assemblies. It was concluded that the totalradionuclide inventory of the high-levelradioactive waste objects at the time of dumpingwas 37 PBq. The difference between this valueand the preliminary estimate of 89 PBq given inthe Russian White Book can be explained by themore accurate information on the actual operat-ing history of the reactors provided to IASAPby the Russian authorities. The correspondinginventory of high-level dumped wastes in 1994was estimated to be 4.7 PBq of which 86% arefission products, 12% activation products, and2% actinides. The main radionuclides in thesecategories were strontium-90, caesium-137,nickel-63, and plutonium-241, respectively.

The rates of release of radionuclides to theenvironment will depend upon the integrity ofmaterials forming the reactor structure, the bar-riers added prior to dumping, and the nuclearfuel itself. For each of the dumped high-levelwaste objects, the construction and compositionof barriers were investigated in detail, weakpoints were identified, and the best estimates ofthe corrosion rates and barrier lifetimes wereused in the calculation of release rates. Externalevents, such as collision with ships or, moregenerally, global cooling following by glacialscouring of the fjords could damage the con-

j

1

pw /I Y — D — Plutonium-241\ \ — • — Plutonium-239+240k Y — • — Americium-241\ \ o Cobalt-60

i «! — a — Nickel-63\ V — « — Nickel-59\ \ — o — Caesium-137T ti — • — Strontium-90 ;

2200 2400 2600

Time (y)2800 3000

Glacial scouring

3200

Shown are examples of predicted release rates related to the climate change sce-nario applied to a single reactor dumped in the Novaya Zemlya Trough. Therelease of different radionuclides is assumed to be driven by corrosion until theyear 3000 when, due to glacial scouring, the total disruption of all barriers andrelease of the whole remaining inventory is assumed to take place. (Neil Lynn,Royal Naval College, UK/Akira Wada, Ninon University, Japan)

24

tainment. This would lead to faster releases ofradionuclides to the environment. In order toadequately represent the possible range ofrelease rates to the environment, three releasescenarios were considered:• a best estimate scenario — release occurs viathe gradual corrosion of the barriers, waste con-tainers and the fuel itself;• a plausible worst case scenario — normalgradual corrosion followed by a catastrophicdisruption of two sources at a single dump site(the fuel container and the reactor compartmentof the icebreaker) in the year 2050 followed byaccelerated release of the remaining radionu-clide inventory of these sources; and• a climate change scenario — corrosion up tothe year 3000 followed by instantaneousrelease, due to glacial scouring, of the radionu-clide inventory remaining in all sources.

It should be noted that no attempt was madeto assign probabilities to the events described inplausible worst case and climate change scenar-ios and the consequences have been assessed onthe assumption that such events will occur in theyears indicated.

For the best estimate scenario, the combinedrelease rate from all sources peaks at about3000 GBq/a (GBq = 109 Bq) within the next 100years with a second peak of about 2100 GBq/ain about 300 years time. For most of the remain-ing time, total release rates lie between 2 and 20GBq/a. The plausible worst case scenarioresults in a release "spike" of 110 000 GBq fol-lowed by releases of between 100 and 1000GBq/a for the next few hundred years due to theaccelerated release of radionuclides from thefuel container and reactor compartment of thenuclear icebreaker. In the climate change sce-nario, which assumes that glacial scouring caus-es an instantaneous release of the remaininginventory of all the wastes in 1000 years time,about 6600 GBq are released.

Modelling and assessment

The calculated release rates were used withmathematical models of the environmentalbehaviour of radionuclides to estimate radiationdoses to people and biota. Different modellingapproaches were adopted and experts from sev-eral countries and from the IAEA participated inthe exercise. Substantial effort was devoted to asynthesis of existing information on marineecology, oceanography, and sedimentology ofthe target area as a basis for model development.

IAEA BULLETIN, 39/1/1997

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Maximum total annual individual doses for selected population groups(Doses in microsieverts)

Scenario Annual doses to seafood consumers(Groups 1 and 3)

<0.1

<1

0.3

Annual doses to military personnel(Group 2)

700

4000

3000

Best estimate scenario

Plausible worst case scenario

Climate change scenario

Notes:

I microsievert = 10 Sv.

For perspective, the annual doses to the critical Groups 1 and 3 from naturally occurring polonium-210 in seafood are 500 microsievert

and 100 microsievert, respectively.

The worldwide total average annual dose from natural background radiation is 2400 microsievert.

Specific processes were identified as peculiar tothe area and, thus, of potential importance forincorporation into models. Because of the needto provide predictions on very diverse space andtime scales, a number of different models for thedispersal of radionuclides within and from theArctic Ocean were developed.

Two main modelling approaches were adopt-ed: compartmental or box models; and hydrody-namic circulation models. In addition, onehybrid model (using compartmental structurebut at a finely-resolved spatial scale) was devel-oped and applied. By modelling advective anddiffusive dispersal, compartmental models pro-vide long timescale, spatially-averaged, far-fieldpredictions, while the hydrodynamic modelsprovide locally resolved, short timescale results.

Separate attention was devoted to one of themost poorly-quantified transport pathways —sea-ice transport. A simple exemplar calcula-tion, or scoping exercise, demonstrated that, forthe radioactive waste sources considered here,sea-ice transport would make only a small con-tribution to individual dose compared with thetransport of radionuclides in water.

For the estimation of doses to individuals,three population groups were considered.Calculations of individual doses were under-taken for time periods covering the peak indi-vidual dose rates for each of the three scenariosidentified previously. Three groups weredefined:

Group 1. A group living in the Ob andYenisey estuaries and on the Taimyr and Yamalpeninsulas whose subsistence is heavily depen-dent on the consumption of locally caught KaraSea fish, marine mammals, seabirds and theireggs, and who spend 250 hours/year on theseashore. These habits are also typical of sub-sistence fishing communities in other countriesbordering the Arctic.

Group 2. A hypothetical group of militarypersonnel patrolling the foreshores of the fjordscontaining dumped radioactive materials, forassumed periods of 100 hours/year. The expo-sure pathways considered include external radi-ation and the inhalation of seaspray and re-sus-pended sediment.

Group 3. A group of seafood consumersconsidered representative of the NorthernRussian population situated on the Kola penin-sula eating fish, molluscs and crustaceans har-vested from the Barents Sea. No considerationwas given to the consumption of seaweed ormarine mammals, nor to external radiation.

Maximum total annual individual dosesfor selected population groups

The maximum annual individual doses ineach critical group of seafood consumers(Groups 1 and 3) for all three scenarios aresmall and very much less than variations in nat-ural background doses. (See table.) Doses to thehypothetical critical group of military personnelpatrolling the fjords (Group 2) are higher but,nevertheless, comparable to natural backgroundradiation doses.

Collective doses were estimated only for thebest estimate release rate scenario. The collec-tive dose to the world population arising fromthe dispersion of radionuclides in the world'soceans (nuclides other than carbon-14 andiodine-129) were calculated for two time peri-ods: (i) up to the year 2050 to provide informa-tion on the collective dose to the current genera-tion; and (ii) over the next 1000 years, a timeperiod which covers the estimated peak releases.

Because of the increasing uncertainties inpredicting future events, processes, and devel-opments, it was not considered meaningful to

IAEA BULLETIN, 39/1/1997 25

SPECIAL REPORT

Main conclusions of the International Arctic Seas Assessment Project

• Monitoring has shown that releases from identified dumped objects are small and localized tothe immediate vicinity of the dumping sites. Overall, the levels of artificial radionuclides in the Karaand Barents Seas are low and the associated radiation doses are negligible when compared with thosefrom natural sources. Environmental measurements suggest that current annual individual doses from allartificial radionuclides in the Barents and Kara Seas are at most 1 to 20 microsievert. The main contrib-utors are global fallout from nuclear weapons testing, discharges from nuclear fuel reprocessing plantsin western Europe, and fallout from the Chernobyl nuclear accident.• Projected future doses to members of the public in typical local population groups arising fromradioactive wastes dumped in the Kara Sea are very small, less than 1 microsievert Projected futuredoses to a hypothetical group of military personnel patrolling the foreshores of the fjords in which wasteshave been dumped are higher, up to 4000 microsievert but still of the same order as the average naturalbackground dose.• Doses to marine fauna are insignificant, orders of magnitude below those at which detrimentaleffects on fauna populations might be expected to occur. Furthennore, these doses are delivered toonly a small proportion of the local fauna populations.• On radiological grounds, remediation is not warranted. Controls on the occupation of beaches andthe use of coastal marine resources and amenities in the fjords of Novaya Zemlya used as dump sitesmust, however, be maintained. This condition is specified to take account of concerns regarding the pos-sible inadvertent disturbance or recovery of high level waste objects and the radiological protection ofthe hypothetical group of individuals occupying the beaches adjacent to the fjords.

Recommendations of the InternationalArctic Seas Assessment Project

• Efforts should be made to locate and identi-fy all high level waste objects.• Institutional control should be maintainedover access and activities in the terrestrial andmarine environments in and around the fjordsof Novaya Zemlya in which dumping hasoccurred.• If at some time in the future, it is proposedto terminate institutional control over areas inand around these fjords, a prior assessmentshould be made of doses to any new groups ofindividuals who may be potentially at risk.• In order to detect any changes in the condi-tion of the dumped high level wastes a limitedenvironmental monitoring programme at thedump sites should be considered.

extend the assessment beyond 1000 years. Theestimated collective doses are 0.01 marvSv and1 manSv, respectively in the two time periods.The calculations provide some illustration ofthe temporal distribution of the dose.

Appropriate global circulation models wereused to calculate collective doses from carbon-14 and iodine-129. which are long-lived andcirculate globally in the aquatic, atmospheric

and terrestrial environments. Assuming theentire carbon-14 inventory of the wastesreleased around the year 2000 and integratingthe dose to the world's population over 1000years into the future (i.e., to the year 3000)yields a collective dose of about 8 manSv. Thecorresponding value for iodine-129 is muchlower at 0.0001 manSv. Thus, the total collec-tive dose over the next 1000 years to theworld's population from all radionuclides inthe dumped radioactive waste is of the order of10 manSv. In contrast, the annual collectivedose to the world's population from naturaloccurring polonium-210 in the ocean is esti-mated in other studies to be about three ordersof magnitude higher. It is also informative tocompare the collective dose associated withwastes dumped in the Kara Sea with the collec-tive dose estimated for low-level radioactivewaste dumped in the Northeast Atlantic. Thecollective dose to the world population is 1manSv over 50 years and 3000 manSv over1000 years from the latter practice.

The radiation dose rates to a range of pop-ulations of wild organisms, from zooplanktonto whales, were calculated and found to bevery low. The peak dose rates predicted in thisassessment are about 0.1 milligray per hour —a dose rate that is considered unlikely to entailany detrimental effects on morbidity, mortali-ty, fertility, fecundity, and mutation rate that

26 IAEA BULLETIN. 39/1/1997

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may influence the maintenance of healthy pop-ulations. It is also relevant to note that only asmall proportion of the biota population inlocal ecosystems could be affected by thereleases.

Remediation options

Feasibility and costs. A preliminary engi-neering feasibility and cost study was conduct-ed for five remediation options for the contain-er of spent fuel from the nuclear icebreaker.This source was chosen because it contains thelargest radionuclideJ inventory among thedumped waste objects and is the best docu-mented regarding construction and introducedcontainer barriers.

The five specific options initially selectedfor evaluation were:

Option 1. Injection of material to reducecorrosion and to provide an additional releasebarrier.

Option 2. Capping in situ with concrete orother suitable material to encapsulate the object.

Option 3. Recovery to a land environment.Option 4. Disposal into an underwater cav-

ern on the coast of Novaya Zemlya.Option 5. Recovery and underwater trans-

port to a deep ocean site.Further consideration of these options by

salvage experts screened out options 1,4 and 5.Option 1 was screened out on the grounds thatthe spent fuel package has been previouslyfilled with a special polymer, Furfurol(F),which might make the injection of additionalmaterial difficult. Option 4 was omitted fromfurther consideration because the creation of anunderwater cavern would be too expensive aproposition for a single recovered source andwould have to be justified in a larger context.Option 5 was discarded because first, it isdoubtful whether special approval could beobtained from the London Convention 1972 foran operation that entailed re-dumping of a high-level waste object in the ocean, and second,underwater transport on the high seas wouldinvolve undue risks of losing the package dur-ing carriage to a new disposal site.

Further evaluation of remedial actions wastherefore confined to the two remaining options,i.e., in situ capping and recovery for land treat-ment or disposal. Both options were deemedtechnically feasible. The costs of marine opera-tions were estimated to be in the range US $6million to $10 million. It should be appreciated

that for the recovery option, there would bemajor additional costs to those considered herefor subsequent land transport, treatment, stor-age, and/or disposal. Radiation exposures to thepersonnel involved in remedial actions wereconsidered as was the likelihood of a criticalityaccident. It was concluded that, with the appro-priate precautions and engineering surveys pro-posed as a basis for proceeding with remedia-tion, the radiation risks to the personnel involvedin remedial activities would not be significant.

Radiological protection considerationsfor the justification of remediation. The basicconcepts of radiological protection relevant tothis project are those recommended by theInternational Commission on RadiologicalProtection (ICRP) and incorporated into theInternational Basic Safety Standards forProtection against Ionizing Radiation and forthe Safety of Radiation Sources (BSS) of theIAEA and other international organizations.These documents identify two classes of situa-tion in which humans may be exposed to radia-tion — those in which protection measures canbe planned prospectively, before sources ofexposure are introduced, and other situations,where the sources of exposure are already pre-sent and protection measures have to be consid-ered retrospectively. These are characterizedrespectively as practices and interventions.

The situation considered in the IASAP studyfalls within the category of interventions. In thiscase, intervention could in principle be appliedat source or, following radionuclide release, tothe environmental exposure pathways throughwhich humans might be exposed. Interventionat source could include, for example, the intro-duction of additional protective barriers for thewaste objects to prevent radionuclide release.Intervention applied to environmental exposurepathways could involve restricting consumptionof contaminated food and/or limiting access tocontaminated areas. In either case, it is requiredthat remedial actions are justified on the basisthat the intervention does more good than harm,i.e., the advantages of intervening, including thereduction in radiological detriment, outweighthe corresponding disadvantages, including thecosts and detriment to those involved in theremedial action. Furthermore, the form andscale of any intervention should be optimized toproduce the maximum net benefit.

There are a number of factors that require con-sideration in reaching a decision about the needfor remedial actions. From a radiological protec-tion perspective, the most important aspects are:

IAEA BULLETIN, 39/1/1997 27

SPECIAL REPORT

• The doses and risks to the most exposed indi-viduals (the critical group) if action is not takenand the extent to which their situation can beimproved by taking action; and• The total health impact on exposed popula-tions and how much of it can be avoided by tak-ing remedial action. The total health impact isproportional to the collective dose, i.e., the sumof individual doses in an exposed population.

The dumped high-level radioactive wastesin the Kara Sea and adjoining fjords are in dis-crete packages that are expected to leak atsome time in the future. They therefore consti-tute a potential chronic exposure situationwhere the concern relates to future incrementsof dose to exposed individuals resulting fromreleases of radionuclides from the dumpedwastes. Depending on the physical conditionof these sources, intervention (remediation) atsource is the most viable course of actionrather than intervention at some later time inenvironmental exposure pathways. The pre-condition for intervention is that it is both jus-tified and optimized.

Currently, there are no internationallyagreed criteria for invoking a requirement toremediate in chronic exposure situations exceptin the case of exposure of the public to radon, anaturally occurring radioactive gas, where inter-national guidance suggests an action level at anincremental annual dose in the range 3 to10 millisievert (3000 to 10 000 microsieverts).Both the ICRP and IAEA have under develop-ment guidance for applications to other types ofintervention situation.

The radioactive waste sources in theBarents and Kara Seas are predicted to giverise to future annual doses of less than 1microsievert to individuals in populationgroups bordering the Kara and Barents Seas.The risk of fatal cancer induction from a doseof 1 microsievert is estimated to be about5 x 108 — a trivial risk. Therefore, members oflocal populations will not be exposed to signif-icant risks from the dumped wastes. The pre-dicted future doses to the members of thehypothetical group of military personnelpatrolling the foreshores of the fjords ofNovaya Zemlya are higher than those predict-ed for other members of the public and arecomparable with doses from natural back-ground radiation. (The average annual radia-tion dose due to natural background includingradon exposure is 2400 microsieverts.) Takinginto account that the doses to this hypotheticalgroup could be controlled if required, none of

the calculated individual doses indicates aneed for remedial action.

Although the risks to each individual may betrivial, when summed over a population somehealth effects might be predicted to arise as aresult of the additional exposure. These healtheffects are considered to be proportional to thecollective dose arising from the dumped radioac-tive wastes. The collective dose to the world'spopulation over' the next 1000 years from theradioactive wastes dumped in the Barents andKara Seas is of the order of 10 man-Sv. This cal-culated collective dose is small but can, never-theless, be considered further in reaching a deci-sion about the need for remediation. A simplifiedscoping approach to considering collective dosein a decision-making framework is to assign amonetary value to the health detriment thatwould be prevented if remedial action was imple-mented. If this scoping approach indicates thatremedial action might be justified, a moredetailed analysis in which the components of thecollective dose are more closely examined wouldbe warranted. Using the scoping approach it canbe shown that remedial measures applied to thelargest single source (the spent fuel package fromthe nuclear icebreaker) costing in excess of US$200 000 would not appear to offer sufficientbenefit to be warranted. Since any of the pro-posed remedial actions would cost several mil-lion US dollars to implement it is clear that, onthe basis of collective dose considerations, reme-diation is not justified.

Overall, from a radiological protectionviewpoint, including consideration of the dosesto biota, remedial action in relation to thedumped radioactive waste material is not war-ranted. However, to avoid the possible inadver-tent disturbance or recovery of the dumpedobjects and because the potential doses to thehypothetical group of military personnelpatrolling the Novaya Zemlya fjords used asdump sites are not trivial, this conclusiondepends upon the maintenance of some form ofinstitutional control over access and activities inthe vicinity of those fjords.

Finally, it is noted that the discussion of theIASAP study was confined to the radiologicalaspects of decision-making regarding the needfor remedial action. The political, economic,and social considerations that must form animportant part of the decision-making processare not considered and are largely matters forthe national government having jurisdiction andresponsibility regarding the dumped radioactivewastes. O

28 IAEA BULLETIN, 39/1/1997