Radiological Assessment - Brookhaven National Laboratory · · 2014-02-06radiological doses either to aquatic or terrestrial animals or plants above ... large difference between

8-1 SITE ENVIRONMENTAL REPORT 2000

CHAPTER 8: RADIOLOGICAL DOSE ASSESSMENT

SITE ENVIRONMENTAL REPORT 2000

RadiologicalDoseAssessment

B R O O K H A V E N

N A T I O N A L

L A B O R A T O R Y

Chapter 8

Radioactive materials are used in many research activities at Brookhaven

National Laboratory. The radiological impact of these materials and

potential effective dose equivalents to members of the public from various

pathways such as inhalation, ingestion, and skin absorption were evaluated

to show compliance with EPA and DOE regulatory limits. During 2000,

very low levels of radioactive gaseous and particulate emissions were

released from facility operating stacks and ventilation exhausts.

BNL operations had minimal radiological dose impact to the public and

the environment. The ambient external dose measured at BNL was similar

to background levels. The effective dose equivalent to the maximally

exposed individual from air emissions was calculated to be 0.18 mrem

(1.8 �Sv). This dose is insignificant when compared to the EPA regulatory

public air-dose limit of 10 mrem/yr (100 �Sv/yr). The annual effective

dose equivalent to an individual consuming contaminated fish and deer

was 3.10 mrem (31 �Sv). The maximum dose impact to the individual

from both the air and food pathways combined was 3.28 mrem (33 �Sv).

This is less than 4% of the DOE regulatory dose limit for members of the

public from all pathways which is 100 mrem (1000 �Sv).

Five remediation projects with potential air emissions of radionuclides in

excess of 1% of the National Emissions Standards for Air Pollutants were

also evaluated. This evaluation showed that the cumulative effective dose

equivalent from all of these sources was 0.11 mrem (1.1 �Sv).

In 2000, the dose to aquatic and terrestrial biota was also evaluated. No

radiological doses either to aquatic or terrestrial animals or plants above

natural background were recorded from BNL operations.

8-2SITE ENVIRONMENTAL REPORT 2000


088-400

090-400

080-400

049-400

030-400

013-400011-400017-400

034-400

082-400

109-400

126-400

122-400

108-450

105-400

066-400

038-450

111-400

054-400

075-402

084-400 085-400

085-401 086-400

074-450074-451

037-400

073-400

063-400

053-400

100 300 500

0 1000

Meters

Feet

034-401

025-400

034-403034-405

8.1 AMBIENT RADIATION

8.1.1 ONSITE AND OFFSITE AMBIENT RADIATIONMONITORING

BNL continuously monitors ambientradiation doses from Laboratory operationsusing a system of passive area monitors calledthermoluminescent dosimeters (TLDs). TheTLDs are located onsite and offsite andmeasure direct external beta and gammaradiation. These TLDs are made of crystals,known as chips, that are made of calciumfluoride (Ca F2:Dy) and lithium fluoride (LiF:Mg, Ti). The TLDs are suspended free inambient air approximately three feet (onemeter) above the ground surface.

Thirty-six TLDs were posted on the BNLsite and 18 posted at offsite monitoringlocations in 2000 asshown on Figures 8-1and 8-2, respectively.Figure 8-1 does notshow the locationof 044-400 and045-400 TLD as

Figure 8-1. Onsite TLD Locations.

N

GPS readings were not available. The BNL siteis divided into grids and the TLDs are as-signed numbers based on these grids. Theoffsite TLDs do not have grid numbers andare assigned a grid of 000 followed by aunique numerical identifier. The offsite TLDlocations are divided into 16 sectors for winddirections. The onsite and offsite TLDs wereexchanged on a quarterly basis to determinewhether BNL operations had any impact onthe ambient external radiation levels of thesurrounding area. The Table 8-1 correlatedTLD number to location.

The control TLD 075-000 dose was calcu-lated as an arithmetic average of 30 TLDsstored in a lead-shielded container (in Bldg.

535) to reduce dose from



Figu

re 8

-2.

Offs

ite

TLD

Loc

atio

ns.

01

23

45

01

23

Kilo

met

ers

Mile

s

RIV

ER

HE

AD

OLD

FIE

LD

VIL

G O

F B

RA

NC

H

QU

OG

UE

ISLI

P

WE

ST

HA

MP

TO

N

BE

AC

H

WA

DIN

G R

IVE

R

YA

PH

AN

K

CO

RA

M

ME

DF

OR

D

William Fl oyd Parkwy

Long

Isl

and

Sou

nd

Pec

onic

Bay

Mor

iche

sB

ay

Atla

ntic

Oce

an

000-

403

000-

408

NN

E

E

SE

S

SW

W

NW

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

BE

LLE

TE

RR

E

PO

RT

JE

FF

ER

SO

N

RO

CK

YP

OIN

T

000-

418

000-

417

000-

416

000-

415

000-

419

000-

422

BE

LLP

OR

T

000-

411

000-

412

000-

413

SH

INN

EC

OC

K B

AY

CE

NT

ER

MO

RIC

HE

S

000-

425

000-

426

000-

402

000-

424

000-

420S

HO

RE

HA

M

CA

LVE

RT

ON

NA

TIO

NA

LC

EM

ET

ER

Y

Shi

nnec

ock

Bay

PA

TC

HO

GU

E

NO

RT

HS

HIR

LEY

000-

423 00

0-41

4

000-

401

Exp

essw

495

ray

ILo

ngsl

and

000-

451

HE

AD

OF

HA

RB

OR

PO

QU

OT

T

LAK

E G

RO

VE

SP

OR

TS

ME

N'S

CLU

B

N



natural sources and cosmic radiation. Themeasured dose of the control TLD was 16 ± 10mrem (0.16 ± 0.1 mSv) for each of the fourquarters and 64 ± 40 mrem (0.64 ± 0.40 mSv)for the entire year. The highest dose recorded(104 ± 40 mrem /year [1.0 ± 0.4 mSv]) wasmeasured at the West Firebreak (053-400).However, the large standard deviation associ-ated with that measured value indicatessignificant variation in dose measurements at95% probability. During 2000, the onsite and

offsite ambient doses for all quarters weresimilar to natural background doses, with afew exceptions. The onsite average dosecalculated for the 34 onsite TLDs was 88 ± 7mrem (0.88 ± 0.07 mSv) per year. In compari-son, the average of the 17 offsite TLDs was 86± 9 mrem (0.86 ± 0.09 mSv) per year.

The quarterly average and yearly dose forTLD 054-400 (Bldg. 914) was not calculatedinto the onsite average in Table 8-1 due to thelarge difference between the first and subse-

��

�� !��"� ��#� ��$#�% $�&��

�� !!��" �� #�$ �� %� �� %� �� &�� &�� %'�(�) �� &��#�$��*+� �� *,"-�� *,"-�� *,"-�� &�� .�//�!�01'�$! �� .�02 �� 2($1/�3�!�%$�$�1/ �� *��*�,,��,"! �� %�� &�$��.14�� .��,�� %�� %��3�$� �� *,"-��*��%$1(� �� *,"-��01,,��$1�� *,"-��01,,��$1�� *,"-�� *,"-�� %� �� *,"-�� 0 0�� 01/$�1,�.56��7-�� !��"��'�� $# ��

�� !�� "

�#��$��%��&��'�� %� �� (��&�� )%��)��



quent quarter measurements, and the loss ofthe TLD in the fourth quarter. This TLD hadan extreme value for the first quarter (543.3mrem) and is not an accurate representationof environmental dose in this area. After aninvestigation, it was determined that the highreading for this quarter may be attributable tothe sky-shine phenomenon that occurs duringthe operation of the g-2 experiment. Thisexperiment was operational only during thefirst quarter of 2000. The impact on dosefrom the g-2 experiment will be evaluatedfurther in 2001. The second and third quartermeasured doses of 18.3 and 19.0 (respectively)are representative of doses normally observedin the environment. Statistical comparisonwith data from previous years also indicatesthat the overall trend of environmental dosein this area was in the 17- to 20-mrem rangefor each quarter. The fourth quarter TLD wasnot recovered due to construction activities atthe Booster Application Facility. It was de-cided that inclusion of this TLD in thesitewide average would skew the mean, thusmaking it difficult to interpret the data nowand in the future.

The 088-400 TLD (S6) location had anextreme value in the data set that was so farremoved from other external dose values thatthe chance probability of it being a validmember of the data set was remote. Theproximity of TLD 088-400 to the radiologi-cally posted Waste Management Facility isknown to have contributed to high radiationdose for this TLD. Public access to radiologi-cal contamination areas is not permitted andauthorized workers are routinely monitored.Therefore, the dose values for this TLD arereported in this SER but excluded fromaveraging because it was not an accuraterepresentation of onsite environmental dose.

During 2000, the ambient dose was basedon the average of the two LiF: Mg, Ti chips.Prior to 2000, all four chips (including the twoCaF2:Dy chips) were used to calculate dose.This change was made based on the results ofa fade study (Harshaw Type 8807 Environmen-tal Dosimeter [TLD Card 2211]) done onenvironmental dosimeters (EML-DOE 2000).The study concluded that the CaF2 elementshowed much higher fading after 60 days ofexposure in the field, and would thereforeunderestimate the dose. The LiF element fadewas negligible for extended periods of expo-

sure in the field. Normally, environmentalTLDs are posted in the field for about 90 daysbut can be posted for extended periods,sometimes up to 120 days. Due to this changein monitoring, the environmental ambientdose for 2000 is about 20-30% higher than inprevious years.

The average doses measured by theunshielded TLDs offsite were not significantlydifferent from the average doses measured bythe shielded TLDs. Therefore, it can be con-cluded that BNL operations had no measurableimpact to the environment. The offsite TLDdoses are summarized in Table 8-2.

8.1.2 BUILDING 650 SUMP OUTFALL MONITORING

The Building 650 sump outfall is a local-ized area of radiologically contaminated soilsapproximately 800 feet northeast of Building650. This area of contamination is beingaddressed under the Environmental Restora-tion Program (Operable Unit IV, Area ofConcern [AOC] 6). Radionuclides identifiedin the AOC 6 soil include strontium-90,cesium-137, and isotopes of europium andplutonium.

The area around the sump is fenced andposted as a radiological area to prevent anyunauthorized entry. Twenty-one TLDs arelocated within the sump area; and an addi-tional four TLDs are located on the fence, oneat each (north, east, west, and south) compassdirection (see Figure 8-3). Additionally, twocontrol TLDs are kept in a lead-shieldedcontainer as background TLDs for compari-son.

The quarterly TLD doses measured in2000 for the Building 650 Sump Outfall aregiven in Table 8-3. Consistent with previousyears, the data show that the highest concen-tration of radionuclides was at the C4 loca-tion. The annual dose measured at C4 was1.47 rem (15 mSv). The doses decrease southof the C4 grid towards D4 location and westgrid at C3 location to 0.8 rem (8 mSv) and 0.7rem (7 mSv), respectively. The dose measuredat the A1 location was higher than expectedfor the first quarter because the TLD wasfound on the ground instead of the three foot(one meter) height above the ground. Thedose was higher due to the shorter distancefrom the radiological source. The annual dosemeasured at the sump fence was similar to thecontrol TLDs, demonstrating that the radia-



D4D3

D2

D1

C2C3

C4

B4B3B2

B1

A1A2 A3 A4 F17

F18

F19

C1

C5

D5

E5E4

E3

0 10

0 10 20 30

Meters

Feet

F16

Outfall Pipe

SCALE

N

Figure 8-3. Building 650 SumpOutfall TLD Network.

tion field was localized to the immediate area.Entry into the sump outfall area was restrictedto authorized personnel and therefore was notan exposure hazard to site workers or mem-bers of the public. Radiological dose toauthorized personnel is monitored to ensurethat their dose is below all DOE limits.

8.2 AIR EMISSIONS

The U.S. Environmental ProtectionAgency (EPA) has established radiation doselimits to members of the public from airborneradionuclide emissions released from DOEfacilities. BNL operations are subject to therequirements of 40 CFR Part 61, Subpart H,“National Emission Standards for HazardousAir Pollutants” (NESHAPs). This regulationspecifies the monitoring and reporting re-quirements for various types of radionuclidesand mandates that no member of the publicreceives a dose greater than 10 mrem (0.1 mSv)per year from exposure to airborne radionu-clide emissions, other than radon, releasedfrom a DOE facility. The regulation alsorequires the DOE facility to submit an annualreport to EPA that describes the atmosphericemissions for the preceding year and associ-ated offsite impacts.

��'' ��

�� !��"� ��#� ��$#�% $�&��

�8�� 7�$��1(��$� �� 8�� 7�$��1(��$� �� 8�� 7�$��1(��$� �� 8�� 7�$��1(��$� � �� 8�� 7�$��1(��$� � �� 8�� 7�$��1(��$� � �� 8�� 7�$��1(��$� �� 8�� %'991,��01'/$��06 �� 8�� 7�$��1(��$� �� 8�� 7�$��1(��$� � �� 8�� 7�$��1(��$� �� 8�� 7�$��1(��$� �� 8�� %��$:��!$�$� �� 8�� 7�$��1(��$� �� 8�� #�"��;!,��3�� 8�� 0�,7��$1/� �$��0�� 8�� %(1�$!��/<!�0,'� �� 01/$�1,�.56��7-�� !��"��'�(��'' ��$# �� *�� '��'�%� �� (��&��

�#��$��#��&��



��)��"�*+��,��-��'��$#�.��/��0��

�� #� ��$#�$�&��

� �� * � � � � � � � � �� *� � � � �� *� �� *� � � �� 0 �� 0� � � � � � � � � �� 0� �� 0� �� 0� �� 6 �� 6� �� 6� � � �� 6� �� 6� �� / �� / ��%� � � � � � � � � � � �� / �� / ��&� � � � � � � � � �� 01/$�1,�.56�� 01/$�1,�.56��

�� +�� (%� ��%� %��

8.2.1 AIR DISPERSION MODEL

Compliance with NESHAPs regulations isdemonstrated through the use of EPA’s CAP88-PC (Clean Air Act Assessment Package-1988)computer model program. The CAP88-PCcomputer code uses a Gaussian plume modelequation to estimate the average dispersion ofradionuclides released from elevated stacks ordiffuse sources (EPA 1992). The programcomputes radionuclide concentrations in air,rates of deposition on ground surfaces, andconcentrations in food (where applicable) tocalculate a final value for projected dose at thespecified distance from the release point. Theprogram supplies both the calculated effectivedose equivalent (EDE) to the maximallyexposed individual (MEI) and the collectivepopulation dose within a 50-mile radius of theemission source. This model provides veryconservative dose estimates in most cases. Forpurposes of modeling the dose to the MEI, all

emission points are located at the center of thedeveloped portion of the BNL site. Themodeling programs are based on low-levelenvironmental releases and chronic intakes.Input parameters used in the model includeradionuclide type, emission rate in curies peryear, stack parameters such as height anddiameter, and emission exhaust velocity. Site-specific weather and population data were alsoused for the assessments. Weather data weresupplied by measurements from BNL’smeteorological tower. Data include windspeed, direction, frequency, and temperature.Population data for the surrounding area werebased on a population survey by the LongIsland Power Authority (LIPA 1999). Sincevisiting researchers and their families mayreside at the onsite apartment area forextended periods of time, these residents werealso included in the population file used fordose assessment.



8.2.2 MAXIMALLY EXPOSED INDIVIDUAL

The MEI is defined as a hypotheticalperson who resides at the nearest location andhas a lifestyle such that no other member of thepublic can receive a higher dose than thisindividual. The MEI is assumed to reside 24hours a day, 365 days a year at the BNL bound-ary in the downwind direction, and consumescontaminated fish and deer during the year. Inreality, it is a highly unlikely worst-case scenariothat such a combination of maximized dose toany single individual would occur.

8.2.3 DOSES FROM DIFFUSE AND NONPOINT SOURCES

The NESHAPs review process evaluatessources that have any potential to dischargeradioactive air emissions at BNL. A number ofEnvironmental Restoration Program opera-tions were evaluated in 2000. Although envi-ronmental restoration activities are exemptfrom permitting requirements under theComprehensive Environmental ResponseCompensation and Liability Act, activities withany potential to emit radioactive emissionswere assessed for potential dose to the mem-bers of the public. The CAP88-PC modelingprogram is explicitly designed to modelcontinuous airborne radioactive emissions thatoccur over the course of a single year and isnot well suited for estimating short-term oracute releases. Given this limitation, theevaluations treated the potential emissionsources as if they were continuous annualsources that do not end with the cessation ofthe environmental restoration activities. Theassessment conclusions for the restorationactivities are discussed below. With regard toBNL operations, diffuse sources and nonpointsources that had a potential to emit radionu-clides into the air in quantities that could causean EDE in excess of 1% of the standard wereevaluated, and a detailed discussion of theseoperations is provided in Chapter 4.

8.2.3.1 CHEMICAL/ANIMAL AND GLASS HOLES PIT SOILSTOCKPILE #6B

The soil in stockpile #6B was generatedduring pit excavation. Stockpile #6B containedapproximately 440 cubic yards (336 m3) of soilremoved from the bottom of several pitslocated in the animal/chemical pit area. Lowconcentrations of americum-241, cesium-137,potassium-40, neptunium-237, plutonium-239,plutonium-240, and thorium-232 and natural

uranium isotopes were detected in the samples.Because there was a potential for radiologi-cally/mercury-contaminated soil particles tobecome airborne during loading and shipping,a NESHAPs evaluation was conducted. Usingthe CAP88-PC model for dose and risk assess-ment, the effective dose equivalent to the MEIfrom these activities was estimated at 6.07E-03mrem/year (6.07E-02 �Sv/yr).

8.2.3.2 WASTE CONCENTRATION FACILITY SOILEVACUATION

Soils were removed from the WasteConcentration Facility yard (Building 811) aspart of the underground storage tank andpiping removal project. This activity had arelease inventory of radionuclides in the soilof cesium-137 (464 pCi/g [17.2 Bq/g]) andstrontium-90 (454 pCi/g [16.8 Bq/g]). Usingthe CAP88-PC model, an effective dose equiva-lent of 8.52E-03 mrem/year (8.52E-02 �Sv/yr)to the MEI was estimated.

8.2.3.3 BROOKHAVEN GRAPHITE RESEARCH REACTORDUCT REMOVAL

Sections of the Brookhaven GraphiteResearch Reactor (BGRR) aboveground ductwere sectioned and removed. Radiologicalsamples were taken from the interior surface ofthe ductwork to determine the type andamounts of contamination present. A fixativewas used to contain any loose contaminationand the duct opening was capped and sealed toprevent the spread of contamination. Usingsite-specific meteorological data and currentpopulation data, the EDE to the MEI estimatedwith the CAP-88-PC model was 1.5E-04 mrem/year (1.5E-04 �Sv/yr).

8.2.3.4 AREA OF CONCERN 16 SOIL REMOVAL ACTION

This environmental restoration actioninvolved the excavation of landscape soilcontaminated with low levels of cesium-137 ineach of the six Areas of Concern to a depth ofapproximately one foot (0.36m). Using theCAP-88 model, along with site-specific meteoro-logical data and current population data, theEDE to the MEI was estimated to be 3.66E-02mrem/year (3.66E-01 �Sv/yr).

8.2.3.5 RADIOACTIVE WASTEWATER PROCESSINGOPERATIONS

During a process evaluation of radioactivewastewater processing operations associatedwith the Waste Concentration Facility in



�� 1''�&��!��#� ��12��!��3��4��514-� �� 6��!��7��1�� ,��&� ��

�16�#� �)��" 7�&��5��8��&� ��

�� *#�� )�*� �� *5;� �� .��-�$��1 �!!�/-�5�� * �7�(1��$1�� ,�$� ��=� �);0 6�� 3%�*11!$�� 6��

�� "��$�1/�.:��(�� ,�$� ��

�� ,��$1��.�!$�� ,�$� 6��

�� "��$�1/��99� $!�� ,�$�� '$��,�*��.�!$�� ,�$� 6��

� 0�,1��$��/ ,1!'�� 6�� *�1,1-�� ,�$� ��

�� 0:��!$�� ,�$� ��

�� /7��1/��/$�,�>�&�!$��#-�$� ��

��6 �/7��1/��/$�,�*�1,1-�>�;/!� 6�� #�"� �,��!�� :�0�/$�� 6�� /�,�$� �,�5��1��$1�� 6�� '��).$��-�� 18��$��

��,��-��&��(��.�� /��%� �� *000"��1�� /��(�% �� & ��&��

�� 1�� &��&��(��2� �� /�� %� (��%%�� &��/�� 3��% �� (�� !��(��40��'�5�3�!%%��)��

(��&��/�

Building 811, waste transfer operations inBuilding 810, and the Evaporator Facility inBuilding 802B, a recommendation was made toconduct a NESHAPs evaluation of sources thathave the potential to release small amounts ofradioactive air emissions that are not directedto the High Flux Beam Reactor stack. Includedamong the sources evaluated were vent pipesfor the four aboveground wastewater storagetanks in Building 811, vent pipes for a 15-gallon(57-liter) condensate storage tank, a 5000-gallon(18,925-liter) tritiated water tank in Building802B, and potential fugitive emissions fromleaks in pumps and pipe valves in the wastewa-ter transfer lines connecting the three build-ings. The potential airborne source term wasbased on the information provided in the BNLProcess Assessment Form and emission factorsfrom 40 CFR 61, Appendix D. The CAP88-PCmodel provided a conservative estimate of theEDE to the MEI of 1.76E-03 mrem/year (1.76E-02 �Sv/yr).

8.2.4 AIRBORNE PATHWAY - EFFECTIVE DOSE EQUIVALENTCALCULATIONS

In 2000, the Brookhaven Medical ResearchReactor (BMRR) air emissions were monitoredcontinuously. Because the potential for airemission was above 0.1 mrem from the airpathway, continuous monitoring is required.The EDE to the MEI from all radiologicalairborne emission sources combined was 0.18mrem (1.8 µSv). Argon-41 (gaseous, half-life=1.8hours) released from the BMRR was the onlycontributor of this dose. By comparison, thiswas less than 2% of the EPA airborne dose limitof 10 mrem (0.1 mSv) and was statisticallyinsignificant compared to the dose receivedannually from natural background radiation.From a dose perspective, a person living in thestate of Colorado would receive 900 mrem peryear from natural sources and one living inSpokane, Washington about 1,400 mrem year(NCRP 1987). In comparison, Long Island’snatural background dose is relatively low at 300mrem/year. The estimated doses to themaximally exposed individual for radionuclidesreleased from all potential sources of airborneemissions are given in Table 8-4.

8.3 FISH CONSUMPTION - EFFECTIVE DOSEEQUIVALENT CALCULATIONS

Calculations were made to determine thepotential dose impact to the MEI from con-

suming fish taken exclusively from the PeconicRiver. As discussed in Chapter 6, fish fromthe Peconic River and Peconic-fed water bodiescontinue to be analyzed for radiologicalcontent because of known historical radionu-clide discharges from the BNL Sewage Treat-ment Plant. These releases occurred primarilyin the 1950s and 1960s. In 2000, fish samplescollected from the Peconic River were ana-lyzed for gamma-emitting radionuclides; onlypotassium-40 and cesium-137 were above theminimum detection limit. The maximumconcentration, 1.30 ± 0.16 pCi/g (48 ± 5.9mBq/g), wet weight of cesium-137, was de-tected in a composite sample of brown bull-head, a local species of catfish. The cesium-137 concentration in pumpkinseed (a localpanfish) from the same location, analyzed as acomposite sample, was 1.19 ± 0.14 pCi/g (44 ±5.2 mBq/g) wet weight. Chain pickerel had a



concentration of 1.13 ± 0.17 pCi/g (42 ± 6.3mBq/g) of cesium-137. The average concentra-tion of 1.20 ± 0.08 pCi/g (44 ± 2.9 mBq/g) ofcesium-137 for all three species of fish wasused in dose calculations. By comparison, theconcentration of potassium-40, another beta/gamma emitting radionuclide, found in abanana, about 3 pCi/g (111 mBq/g), is higherthan the cesium-137 found in the fish collectedfrom the Peconic River.

For dose evaluation, a MEI was assumed toeat 15 pounds of fish during the course of theyear (NYSDOH 1996). Exclusive consumptionof brown bullhead, pumpkinseed, and chainpickerel at the rate and concentration givenabove would result in an EDE of 0.42 mrem(4.2 µSv) due to cesium-137 concentrations. Bycomparison, the average individual EDEcaused by ingestion of naturally occurringradionuclides in the U.S. is about 40 mrem(400 µSv) per year (NCRP 1987). There wereno radionuclides detected in shellfish, aquaticvegetation, marine waters, and sedimentsabove the minimum detection limit.

8.4 DEER MEAT CONSUMPTION - EFFECTIVE DOSEEQUIVALENT CALCULATIONS

As discussed in Chapter 6, measurementswere made of flesh and liver samples collectedfrom deer taken on BNL property as well asfrom offsite locations. Cesium-137 wasdetected in flesh samples from onsite deer atconcentrations lower than those found inoffsite deer. The onsite average concentrationfound in flesh samples was 1.49 ± 0.27 pCi/g(55 ± 9.9 mBq/g) wet weight. In comparison,the offsite deer flesh sample averaged 1.97 ±0.34 pCi/g (73 ± 12.6 mBq/g) wet weight ofcesium-137. While onsite hunting was notpermitted, there are no physical barrierspreventing deer from migrating beyond thesite boundary. It was, therefore, conceivablethat hunters could occasionally take a deerthat resides predominantly on the BNL site.

In March 1999, the New York State Depart-ment of Health (NYSDOH) Bureau of Envi-ronmental Radiation Protection issued areport examining the possible dose impacts tomembers of the public who consume deer thathave grazed extensively on the BNL site(NYSDOH 1999). In the NYSDOH report, a10mrem/year (100 �Sv/year) dose was used asthe limit for deer meat consumption. Theannual consumption rate of venison was

estimated using the EPA’s Exposure FactorsHandbook, which gives the average intake ofgame meat (for those who consume it) asapproximately 1.1 grams per day per kilogramof body weight (0.018 ounces per day perpound of body weight) (EPA 1996). For a 154pound (70 kilogram) individual, this corre-sponds to about 64 pounds (28 kilograms) ofvenison consumed per year. The same as-sumptions have been adopted for this report.

The potential dose from deer meat con-sumption was calculated using the arithmeticaverage of the cesium-137 concentrationsmeasured in flesh samples collected onsiteand one mile radius around the laboratory. Indose calculations, a wet weight average con-centration (i.e., the concentration in the fleshsample prior to drying for analysis) of 1.85 ±0.33 pCi/g (68 ± 12 mBq/g) was used. Underthe stated assumptions, the committed EDEdue to consumption of 64 pounds (28 kilo-grams) of local deer meat would be equal to2.68 mrem (27 µSv) per year. This is 27% ofthe health advisory limit of 10 mrem (0.1 mSv)established by the NYSDOH. By comparison,the average EDE from eating foods thatcontain naturally occurring radionuclides is 40mrem (0.4 mSv) per year (NCRP 1987).

8.5 COLLECTIVE TOTAL EFFECTIVE DOSE EQUIVALENT

Collective total effective dose equivalent(TEDE), a value used to estimate potentialhealth risks to a population, is the summationof the calculated EDE for each individualmultiplied by the number of individuals in thepopulation being considered.

Assuming that the total number of indi-viduals who routinely consume fish takenfrom portions of the Peconic River near theBNL site was 625, the collective TEDE fromthis pathway was 263 person-mrem (2.6person-mSv). This value was based on themaximum fish concentrations discussed inSection 8.3 above. In comparison, the collec-tive TEDE to the same population fromconsumption of naturally occurring radionu-clides in food was 25,000 person-mrem (250person-mSv) annually.

Since onsite deer hunting was prohibited,the individual dose estimate from meatconsumption calculated in Section 8.4 wasbased on the average cesium-137 concentra-tions. Deer moving beyond BNL boundariescan be legally hunted and consumed, resulting



in collective dose. However, the number ofpeople hunting deer or consuming deer meattaken within a one-mile radius of BNL was nottracked; consequently, the collective dose fromdeer meat consumption was not calculated.

For the air exposure pathway, the CAP88-PC computer model provides collective TEDEestimates using population data for the areawithin a 50-mile radius of the BNL site. Thepopulation data are broken down into thenumber of people living within each of the 16compass sectors at 10-mile radial intervals.Again, argon-41 emitted from the BMRR wasthe largest contributor to the total collectivecommitted effective dose equivalent of 6,437person-mrem (64 person-mSv). This consti-tuted 99% of the total collective dose resultingfrom BNL operations projected for the popu-lation within a 50-mile radius of BNL.

8.6 DOSES TO AQUATIC AND TERRESTRIAL BIOTA

DOE has developed draft screeningmethods to estimate radiological doses toaquatic animals, terrestrial plants, and terres-trial animals using the environmental surveil-lance data. These methods can be used toshow compliance with the requirements forprotection of biota in the DOE Order 5400.1(1988), General Environmental Protection Pro-gram, DOE Order 5400.5 (1990), RadiationProtection of the Public and the Environment, andproposed rule 10 CFR 834, Subpart F (66 FR25380). The absorbed dose to aquatic animalsand terrestrial plants should not exceed 1 rad/day (10 mGy/day), and 0.1 rad/day (1 mGy/day) to terrestrial animals from exposure toradiation or radioactive material released intothe environment.

The average concentrations of radionu-clides measured at the BNL site were used toshow compliance with these proposed limits.The average concentration (0.21 pCi/g or 7.7mBq/g) of cesium-137 was analyzed in soilsamples collected onsite. The draft DOETechnical Standard ENVR–0011 (DOE 2000)was used to evaluate the dose impact to theterrestrial animals. The sum fraction ofradionuclides in soil was 1.01E-02 and passedthe criteria using the Biota ConcentrationGuide calculator given in the standard. Thesite-specific cobalt-60 (0.07 pCi/g or 2.6mBq/g) and cesium-137 (0.16 pCi/g or 5.9mBq/g) concentrations in sediments wereused to calculate dose impacts to the aquatic

animals. The sum fraction of radionuclideswas calculated to be 3.77E-03 in this media.The total sum of the fractions was less thanone, and therefore passed the screeningcriteria for dose to the biota. It can be con-cluded from the biota screening methods thatthere was no radiological dose to aquaticanimals, terrestrial plants and terrestrialanimals from BNL operations. Additionalinformation on the body burden in deer isprovided in Chapter 6, Section 6.3.1.

8.7 SUMMARY AND CONCLUSION

Calculations of EDE from all BNL facili-ties that have the potential to release radionu-clides to the atmosphere indicated thatradiological doses attributable to Laboratoryoperations were well below the limits estab-lished by federal regulations (see Table 8-5).Direct measurement of external radiationlevels by TLDs confirmed that exposure ratesat the site boundary were consistent withbackground levels. No dose was calculated fordrinking water since the majority of homeshave been hooked up to public water supply,and there are no radionuclide plumes abovethe drinking water standards beyond the BNLboundary. As some residents in the hookuparea chose not to accept DOE’s water hookupoffer, DOE began identifying and contactingthese property owners in the summer of 2000to offer free yearly testing of their watersupply.

The EDE calculations presented in thischapter were based on the MEI for eachscenario using the stated assumptions. Giventhis, it is unlikely that any single person couldreceive a radiological dose equal to the sum ofthese individual pathways. The hypotheticalMEI, defined as residing at the northeastboundary of BNL, breathing the air, andconsuming 15 pounds of contaminated fishand 64 pounds of contaminated deer meatfrom onsite sources, would receive 3.28mrem/year (32.8 �Sv/year) total effective doseequivalent. This highly unlikely worst-casescenario was calculated to show that the dosefrom all pathways would still be less than 4%of 100 mrem/year (1 mSv/year) dose limit setby DOE for members of the general public,and is insignificant when compared to theaverage annual dose of 360 mrem/year (3.6mSv/year) (NCRP 1987) from cosmic, terres-trial and radon sources. These MEI doses



demonstrate that in 2000 there was minimalradiological dose impact above the naturalbackground to members of the public and theenvironment from BNL operations.

REFERENCES

66 FR 25380. May 14, 2001. U. S. Department of Energy.�10 CFR 834, Radiation Protection of the public and theEnvironment.� Federal Register.

DOE. 2000. A Graded Approach for Evaluation of RadiationDoses to Aquatic and Terrestrial BIota. Proposed TechnicalStandard, Project No. ENVR-0011. U.S. Department ofEnergy, Washington, DC. June 2000.

DOE Order 5400.1. 1988, General Environmental ProtectionProgram, U.S. Department of Energy, Washington, D.C.Change1: 6-29-90

DOE Order 5400.5. 1990, Radiation Protection of the Publicand the Environment. U.S. Department Of Energy,Washington, D.C. Change 2: 1-7-93

EML-DOE. 2000. 12th International Intercomparison ofEnvironmental Dosimeters, New York, NY.

��+��,��5��'�8��#� ��'��1�!��8��3/�5 ��

8��5 ��4��5�14-� �� "��5 ��&��!��4 8��3/�5 ��" 6��!�� 1#1 �8��3/�5�$�� 1#1

��&�� (��!1/��

�� ;/:�,�$�1/ �� ?��

�11" ��!:�� 0!�� % % ��6��#��$�� 0!�� % % �

&�$�� 6��/��/-�&�$��

��6�6��6��6.��!��!%%�� %�� &��(�� +7�� /�� &�� (%��(�� 1��

��(��(%�� 54��8/ �� $�� % �9��$��%��$�� %%�/��&�(��9��1��

EPA. 1992. User�s Guide for CAP88-PC, Version 2.EPA402B92001. U.S. Environmental Protection Agency.Washington, D.C.

EPA. 1996. Food Ingestion Factors, Exposure Factors Handbook-Volume II. EPA600P95002FB. U.S. Environmental ProtectionAgency. Washington, D.C.

LIPA. 1999. Population Survey 1999: Current PopulationEstimates for Nassau and Suffolk Counties and the RockawayPeninsula. Long Island Power Authority. Uniondale, NewYork. October 1999.

NCRP. 1987. Exposure of the Population of the United States andCanada from Natural Background Radiation. NCRP ReportNo. 94. National Council on Radiation Protection andMeasurements, Bethesda, Maryland.

NYSDOH. 1993. Environmental Radiation in New York State.Bureau of Environmental Radiation Protection, New YorkState Department of Health, Albany, New York.

NYSDOH. 1996. Radioactive Contamination in the PeconicRiver. Bureau of Environmental Radiation Protection, NewYork State Department of Health, Albany, New York.

NYSDOH. 1999. Deer Meat Contaminated With Cs-137 atBrookhaven National Laboratory. Bureau of EnvironmentalRadiation Protection, New York State Department ofHealth, Albany, New York.

Documents

Radiological Assessment - Brookhaven National Laboratory · · 2014-02-06radiological doses either to aquatic or terrestrial animals or plants above ... large difference between