I i'% -

sl $ UNITED STATESNUCLEAR REGULATORY COMMISSION

WASHINGTON, D.C. 20555-0001

December 19, 1997

MEMORANDUM TO:

THRU:

FROM:

SUBJECT:

Michael Bell, Acting ChiefPerformance Assessment and

HLW Integration BranchDivision of Waste Management, NMSS

Keith I. McConnell, Section LeaderPerformance Assessment and

HLW Integration BranchDivision of Waste Management, NMSS

Christep eney,System rmance Analyst (Engr)Performance Assessment andHLW Integration Branch

Division of Waste Management, NMSS

TRIP REPORT FOR BIOMASS OCTOBER 1998 MEETING

On October 20-24, 1997, the International Atomic Energy Agency (IAEA) held the annualplenary session for its Biosphere Modeling and Assessment Methods (BIOMASS) program inVienna, Austria. BIOMASS is a six-year effort that focuses on three main areas or "themes":1) radioactive waste disposal, 2) environmental releases, and 3) biospherc processes.BIOMASS had its initial meeting in October 1996, in Vienna, Austria.

The Nuclear Regulatory Commission has been previously involved in BIOMASS Theme I andits predecessor, Biosphere Modeling and Validation Studies (BIOMOVS II). Theme 1 ofBIOMASS is focussed on implementing and improving the Reference Biosphere Methodologydeveloped in BIOMOVS II. The use of the reference biosphere and critical group concept is acentral issue in implementing a dose- or risk-based standard for high-level waste disposal.Both the legislation currently under consideration by Congress and the recommendations by theNational Academy of Sciences support the use of the concept to calculate the radiologicalimpacts from the facility. Therefore, NRC's main focus in BIOMASS is the continuingdevelopment of guidance on the implementation of the reference biosphere and critical groupconcepts. Gaining international consensus on practical approaches is very important in thenear term.

Model validation and verification efforts are being accomplished in Theme 2, EnvironmentalReleases. Two working groups are underway: 1) dose reconstruction, and 2) remediationactivities. The dose reconstruction working group has focussed on modeling the actual releaseof 1311 from the Hanford PUREX Chemical Separations Plant on September 2-5, 1963. The

I

CONTACT: Christepher McKenney, PAHL/DWM/NMSS415-6663

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remediation activities working group has been modeling past remediation of the Olen RadiumExtraction Site in Belgium and will start, in the near future, modeling possible remediationactivities to reduce residual radioactivity further.

Theme 3 is focussed on specific modeling approaches and currently has working groupsinvolved in modeling (1) tritium moving through the environment, and (2) environmentalcontamination transfer to fruit.

The October meeting of BIOMASS was a plenary session with presentations by all workinggroups in the three themes and separate smaller meetings on various other themes.Additionally, IAEA presented information on special co-operative research projects that may beof interest to BIOMASS participants (for example, the Arctic Sea Study). The agenda andparticipants list is attached. I attended the Theme I meetings during the breakout sessionsbecause of our prior interest in Theme 1.

During the initial overview discussion, it was noted that the U.S. Department of Energy (DOE)was applying to become a sponsor for Theme 1 activities. To help support theme activitiesfinancially, member organizations can agree to support the activity with money, personnel or acombination of the two. Currently, organizations from the United Kingdom, France and Spainare sponsors of Theme 1. While it appears likely that DOE will become a sponsor of Theme 1,actions after the meeting have slowed down the official progress of acceptance. In conjunctionwith the application to be a sponsor, DOE offered to host the spring meeting of Theme 1participants in Las Vegas, Nevada the week before the Intemational High-Level WasteConference in May. Since the October meeting, actions specifically resulting from a separateconference held by DOE contractors, EPRI, and other BIOMASS participants during the firstweek of December to use Yucca Mountain as an example, have resulted in both IAEA andother sponsor organizations to 1) reject the offer to have the spring meeting in Las Vegas, and(2) slow down the approval process for DOE's sponsorship. Carlos Torres, IAEA, informed meon December 9, 1997, that a meeting between IAEA and DOE concerning sponsorship may benecessary. Some of the difficulties also resulted from DOE sending no DOE personnel but aM&O contractor, Jeff Tappen, to represent them, requiring IAEA to request an official statementby DOE that the M&O will represent DOE in Theme 1.

Most of the discussions in the Theme 1 breakout sessions involved discussions on theReference Biosphere Concept document, Assessment Context examples, and the short-term(i.e., next six months) goals of the various working groups. NRC participated in developing thedraft final report on Alternative Assessments Contexts and commented on the ReferenceBiosphere Concept document in an IAEA consultants meeting in June 1997.

The Concept document explains the need for the use of reference biospheres as well as theneed for the activities ongoing in BIOMASS Theme 1. This document works as a strategypaper for the BIOMASS Theme I activities, describing the purpose and need for the refinementof the Reference Biosphere Methodology.

The Alternative Assessments Contexts document focusses on assisting transparency inbiosphere modeling by suggesting that model developers first ask and document the questions,Why?" and what needs to be modeled?" As part of the general discussion on the various

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factors (i.e., assessment purpose, societal factors, radionuclide(s) of interest, etc.) that mayaffect the development of a biosphere model, examples were detailed. The examplesestablished in the Assessment Context document will be fleshed out with more detail by each ofthe other working groups, i.e., the Critical Group task group will develop the details on theappropriate critical group or other exposure group to include in the modeling of the example.The Assessment Context draft examples are attached.

Most of the working groups' short term plans focussed on developing a draft paper on principleswith a few detailed examples by the spring meeting in May, which will be held in Vienna,Austria.

While NRC is not currently a participant in the Theme 2 activities, the Remediation Activitiesworking group could be used as a test case for the DandD software, the Decision Framework,and some of the guidance for decommissioning. The working group is in the second stage ofinvestigating the Olen Radium Extraction Site in Belgium. The first stage was model testing bymodeling the effect of remediation activities performed on the site in the early 1 970s. Thesecond stage, model comparison, is focussed on estimating the effect of various remediationactivities planned to be used to further decontaminate the facility (mainly, the stream andassociated flood plains contaminated by discharges of mRa). The second stage ofinvestigations will start in early 1998, with results due by participants in mid-1998. For moreinformation, the IAEA contact for Theme 2 activities is Ms. K-L. Sjoeblom, whose phone numberis +43-1-2060 22667 and E-mail is K.Sjoeblom@iaea.org.

DISTRIBUTION: CJones, NMSS TMcCartin CPaperiello MFederline LMWebeCDaily, RES PAHL r/f

DOCUMENT NAME: s:%dwm~pahl~camntrip.rep

OFC |PAHL I PAHL I I I

NAME CMyWhey/jcg } Klc't onll I

DATE j12l I97 _12_ _ _ _f/97 I l 1 97 _ | I 197 llOFFICIAL RECORD COPY

BIOMASS Meeting, 20-24 October, 1997Agenda

Monday 20th October

08:30 - 09:30

09:30- 12:00

12:00- 13:00

Registration

Opening Session (Board Room C-04):

BIOMASS Programme Progress (G. Ainsley)Theme I ProgressTask Group I - Principles for the Definition of Hypothetical Critical GroupsTask Group 2 - Principles for the Application of Data to Assessment ModelsTask Group 3 - Consideration of Alternative Assessment ContextsTask Group 4 - Biosphere System Identification and Justification

Theme 2 ProgressDose Reconstruction activitiesRemediation Assessment activities

Theme 3 ProgressTritium activitiesFruits Working Group introduction

Discussion

LUNCH

13:00- 13:30

13:30- 17:30

17:30

RASANET Presentation (Board Room - C04)

Theme activities:

Theme 1: Joint Session (Board Room - C04 )Theme 2: Remediation Assessment Working Group (CO7VI)Theme 3: Tritium Working Group (C0453)

Fruits Working Group (A-27)

RECEPTION

Tuesday 21st October

09:00 - 11:00 Information on other activities and new proposals/suggestions:

e UNSCEAR Activities on Environmental Modelling (B. Bena IUR Activities (P. Co;* New Proposals/Suggestions (participants are encouraged to

participate actively during this session. If you plan to make apresentation please contact the IAEA secretary in advance).

11:00 - 12:30 Theme activities

mnetI)

,ghtrey)

Theme 1:Theme 2:Theme 3:

Task Group Sessions (Board Room - CN4 and B066 i))Remediation Assessment Working Group (Room C07VI)Tritium Working Group (C0453)Fruits Working Group (A-27)

2

12:30 - 14:00 LUNCH

14:00 - 17:30 Theme activities:

Theme 1:Theme 2:Theme 3:

Task Group Sessions (Board Room - C04, B066 1)Remediation Assessment Working Group (Room C07VI)Tritium Working Group (C0453)Fruits Working Group (A-27)

17:30 - 18:30 BIOMASS Theme I Steering Committee Meeting

Wednesday 22nd October

09:00 - 12:30 Special Session (Board Room-C04): IAEA Radiological Assessment Projects

Introduction (A. Gonzdlez)

Radiological Study of the nuclear test sitesat the Mururoa and Fangataufa Atolls

Radiological Conditions at Bikini Atoll:Prospects for resettlement

Radiological Conditions at the SemipalatinskNuclear Test Site in Kazakhstan

(P Fry)

(G. Linsley)

(P. Stegnar)

Results and Conclusions of the InternationalArtic Seas Assessment Project (IASAP)

Discussions

12:30- 1x:00 LUNCH

(K-L. Sjoeblom)

13-3O0- 17:30 Theme activities:

Theme 1:Theme 2:Theme 3:

Task Group Sessions (Board Room - C04, B0661)Dose Reconstruction Working Group (C07VI)Tritium Working Group (C0453)Fruits Working Group (A-27)

Thursday 23rd October

09:00 - 12.00 Theme activities

Theme 1:Theme 2:Theme 3:

Joint session (Board Room - C04)Dose Reconstruction Working Group (CO7VI)Fruits Working Group (A-27)Tritium Working Group (C0453)

12:30 - 14:00 LUNCH

14:00 - 17:30 Theme activities:

Theme 1: Joint session (Board Room - C04)

3

Theme 2: Dose Reconstruction Working Group (CO7VI)Theme 3: Fruits Working Group (A-27)

Tritium Working Group (C0453)

17:30 - 18:30 BIOMASS Theme I Steering Committee

Friday 24th October

09:00 - 12:00 Final Session (Board Room - C04)Presentations summarizing the work done and future plans byWorking/Task Groups ChairsNew proposals discussions

12:00 - 13:00 BIOMASS Coordinating Committee Meeting

K'

BIOMASS Meeting 20 - 24 October 1997Outline Agenda for Theme 1

(Rooms C04 and B0661)(Please note how Theme I fits into the wider BIOMASS Plenary agenda)

Monday 20 October - pm

* Update of Activities: Overall objectives for the week (Secretariat)* Presentations by Task Group Leaders for TG3, TG2, TG4 and TGI

Progress with documents,Objectives for the week,Discussion.

* Reference Biosphere DevelopmentDiscussion

Tuesday 21 October

am

* Presentation of Reference Biosphere Concept Document,Discussion (How to complete!)

pm

* Presentation of Yucca Mountain Local Habit Survey ( J Tappen)* UK Nirex presentation (I Crossland)* Presentation and explanation of Example Assessment Contexts,

Discussion* Implications for Example Reference Biosphere development,

Discussion* BIOMASS- PAAG interactions,

Discussion

Wednesday 21 October - pm

* Presentation of proposals for TG5,Discussion

* Presentation of proposals for TG6,Discussion

* Task Group activities, to develop TG documents and to apply TG activities toExample Reference Biosphere development,

We propose to run these activities in parallel. Rooms will be found andal'-'-7ated according to levels of interest in each TG.

Thursday 21 October

am

* Task Group activities, continuing in parallel

pm

* Task Group activities, continuing in parallel* BIOMASS responses to draft LAEA position paper on Critical Groups and

Biospheres,* Review and discussion of PAAG informal paper on Treatment of the Biosphere in

Repository Assessments* Review and discussion of future action plans for each TG.

IN

BIOMASSTHEME 1- PARTICIPANT'S LIST

1997-10-17

AustriaMs. F. Strebl Oesterr.Forschungszentrum Seibersdorf GesmbH (Austrian Research Cent.)

A-2444 SeibersdorfTel: +43 (2254) 780 3579Fax +43 (2254) 780 3653Email: streblearcs.ac.at

BelgiumMr. N. Lewyckyj

.<:r^vw

Belgium Nuclear Research Center200 BoeretangB-2400 Mol-DonkTel: +32 (14) 332818Fax +32(14) 321056Email: nlewyckyj@sckcen.be

Studienzentrum fOr Kernenergie (SCKICEN)Boeretang 200B-2400 MolTel: +32 14 332852Fax: +32 14 321056Email: lsweeck@sckcen.be

Ms. L. Sweeck

CanadaMr. L. Chamney

FinlandDr. S. Vuori

FranceMr. G. Brachet

Radiation & Environmental Protection Div. IREPD)Directorate of Analysis and AssessmentAtomic Energy Control Board of Canada (AECB)P.O. Box 1046, Station Bo280 Slater StreetOttawa, OntarioTel: + 1 (613) 995 8567Fax: + 1 (613) 995 5086/943 8954E-mail: measures.m@atomcon.gc.ca

VTT Technical Research Centre of Finland, VTT Energy, Nuclear EnergyTekniikantie 4 CEspooP.O.Box 1604EIN-02044 VTTTel: +358 9 456 5067Fax +358 9 456 5000Email: Seppo.Vuori@vtt.fi

DAMIDASEB.P. 12F-91680 Bruyeres-Le-ChatelTel: +33 1 6926 5029Fax: +33 1 6926 7023Email: g.brachet~ldg.bruyeres.cea.fr

Mr. P. Ciffroy Electricit6 de France - Departement Environniment (EDF DER)6, Quai WatierB.P.49F-78401 Chatou CedexTel: +33 1 3087 7259Fax: +33 1 3087 8109Email: philippe.ciffroy~der.edfgdf.fr

I

Mr. J. Daroussin

, t.,-^>,. . -

COGEMA (BUIDEXISES)2, rue Paul DautierBP4F-78141 Velizy-Villacoublay, CedexTel: +33 1 3926 3293Fax: +33 1 3926 2751E-mail:

ANDRAParc de la Croix Blanche1-7 rue Jean MonnetF-92298 Chatenay-Malabry CedexTel: +33 (1) 4611 8286Fax: +33(1)4611 8222Email: Elisabeth.Leclerceandra.fr

Mm. E. Leclerc-Cessac

Ms. M. Menut

Mr. P. Santucci

Mr. F. Siclet

GermanyMs. A. Becker

Scientific Direction - Biosphere and Environmental SectionANDRAParc de la Croix Blanche1-7 rue Jean MonnetF-92298 Chatenay-Malabry CedexTel: +33(1)4611 8310Fax: +33 (1)4611 8222Email: Marianne.Menut@andra.fr

Institut de Protection et de Surete Nucleaire (IPSN) CEN-FAR SERGD60-68 Avenue du G6neral LeclercBP No. 6F-92265 Fontenay-aux-Roses, CedexTel: +33 1 4654 8898Fax: +33 1 4657 6258Email: pascal.santucciiipsn.fr

Electricitd de France - Departement Environniment (EDF DER)6, Quai WatierB.P.49F-78401 Chatou CedexTel: +33 1 3087 7847Fax: +33 1 3087 7336Email: francoise.sicletlder.edftdtfr

GRSSchwertnergasse 1D-50667 K6lnTel: +49 221 2068 784Faxc +49 221 2068 888Email: becegrsmbh.de

Ms. S. Nalezinski S 3.4Bundesamt for StrahlenschutzInstitut fOr StrahlenhygieneIngolstadter Landstrasse ID-85764 OberschleissheimTel: +49 (89) 31603 284Fax: +49 (89) 31603 111Email: SNalezinski4BfS.de

2

JapanMr. M. Naito Power Reactor & Nuclear Fuel Development Corporation

1-9-13-ChomeAkasaka Minato-ku107 TokyoTel: +81 3 3586 3484 (Ext. 2802)Fax: +81 3 3586 2786Email: naitom~pnc.go.jp

LithuaniaMs. E. Maceika

MonacoDr. C. Dovlete

Institute of PhysicsAv. Savanoru No. 231LT-2028 VilniusTel: +370 641 336FaxE-mail:

IAEA Marine Environment Laboratory19 Avenue des CastellansB.P.No. 800MC-98012 MonacoTel: +377 9205-2222Fax: +377 9205-7744Email: dovletecunice.fr

Republic of SloveniaMr. B. Kontic

Russian FederationDr. l. Kryshev

Dr. T. Sazykina

Mr. S. Vorontsov

EIA DepartmentJozef Stefan InstituteJamova 39P.O.Box 100SL-61111 LjubljanaTel: +386 61 177 3791Fax: +386 61 123 1115 OR 273 677Email: branko.kontic@iJS.Si

Institute of Experimental MeteorologySPA "Typhoon"82 Lenin StreetKaluga RegionR-249020 ObninskTel: +7 08439 71289Fax: +7 08439 40910Email: typhoon@storm.iasnet.com

Institute of Experimental MeteorologySPA "Typhoon"82 Lenin Ave.Kaluga RegionR-249020 ObninskTel: +7 (08439) 71698Fax: +7 (08439) 40910Email: typhoon~storm.iasnet.com

RFNC-VNIIEF - SarovMira pr., 37Nizhegorodski Region607190 SarovTel:Fax:E-mail:

3

South AfricaMr. T. Hill

SpainMr. D. Cancio

Mrs. P. Pinedo

Ms. I. Sim6n

SwedenDr. U. Kautsky

SwitzerlandDr. F. van Dorp

Council for Nuclear SafetyP.O. Box 71060046 HennopsmeerHennopsmeerTel: +27 (12) 663 5500Fax: +27 (12) 663 5513Email: thill@cns.co.sa

Jefe, DIAE/CIEMATAvenida Complutense, 22E-28040 MadridTel: +34 (1) 346 6628Fax: +34 (1) 346 6121Email: Canciogciemat.es

DlAE/CIEMATAvenida Complutense, 22E-28040 MadridTel: +34 1 346 6750Fax: +34 1 346 6121Email: pinedo@ciemat.es

DIAEICIEMATAvenida Complutense, 22E-28040 MadridTel: +34 1 346 6683Fax: +34 1 346 6121Email: simon@ciemat.es

Swedish Nuclear Fuel and Waste Management Co.P.O.Box 5864Brahegatan 47S-102 40 StockholmTel: +46 8 459 3419Fax: +46 8 661 5719Email: skbukiskb.se

NAGRAHardstrasse 73CH-5430 WettingenTel: +41 (56) 437 1111Fax: +41 (5b) 437 1207Email: vandorpenagra.ch

United KingdomMr. N. Cooper

Dr. P. Coughtrey

Cooper & Caulcott Ltd.104 Westhall RoadCR6 9HD Warlingham, SurreyTel: +44 1883 624052Fax +44 1883 627215Email: ncooperecixco.uk

Environmental ConsultancyMouchel Consulting Ltd. Environmental ConsultancyWest HallParvis RoadWest Byfleet, WeybridgeKT14 6EZ SurreyTel: +44 1932 337 000Fax +44 1932 350052Email: peter.coughtrey~mouchel.com

4

Mr. l. Crossland

Mr. M. Egan

Dr. P. Humphreys

UK Nirex Ltd.Curie AvenueHarwell, DidcotOX1I ORH OxfordshireTel: +44 (1235) 825 441Fax: +44 (1235) 820 560Email: ian.crossland@nirex.co.uk

AEA Technology plcThomson HouseWA3 6AT Risley, WarringtonTel: +44 1925 254337Fax: +44 1925 254570Email: mike.egan~aeatco.uk

British Nuclear Fuels plcR002 Rutherford HouseRisley, WarringtonWA3 6AS CheshireTel: +44 1925 832 654Fax: +44 1925 832 016Email: p-humphreys~consulancy-services.co

Dr. R. Kios

Mr. R. Little

Aleksandria Sciences37, Coverdale RoadS7 2DD SheffieldTel: +44 114 255 6469Fax: +44 114 258 9557Email: AlekSci@compuserve.com

QuantiSci LtdChiltern House,45 Station Rd.RG9 IAT Henley-on-Thames, OxfordshireTel: +44 1491 410474Fax: +44 1491 576916Email: rlittle~quantisci.co.uk

QuantiSci LtdChiltem House,45 Station Rd.RG9 1AT Henley-on-Thames, OxfordshireTel: +44 1491 410474Fax: +44 1491 576916Email: biomass~quantisci.co.uk

Mr. S. Shah

Mr. G. Smith QuantiSci LtdChiftern House,45 Station Rd.RG9 1AT Henley-on-Thames, OxfordshireTel: +44 1491 410474Fax: +44 1491 576916Email: biomasscquantisci.co.uk

S

Mr. J. Stansby

Mr. T. Sumerling

Mr. J. Titley

Dr. A. Venter

AEA Technology picThomson HouseWA3 6AT Risley, WarringtonTel:Fax:E-mail:

Safety Assessment Management LimitedBeech Tree House, Hardwick RoadRG8 7HW Whitchurch-on-Thames, ReadingTel: +44 (01189) 844 410Fax: +44 (01189) 841 440Email: trevor@sam-ltd.demon.co.uk

National Radiological Protection Board (NRPB)ChiltonDidcotOXII ORO OxonTel: +44 1235 822 763Fax: +44 1235 833 891Email: NRPBEIMC1MA1L.COM

QuantiSci LtdChiltern House,45 Station Rd.RG9 1AT Henley-on-Thames, OxfordshireTel: +44 1491 410474Fax: +44 1491 576916Email: Biomass~quantisci.co.uk

Mr. B. Walters Food Safety & Standards Group - Room 505, Radiological Safety & NutritionDivisionMinistry of Agriculture, Fisheries and FoodErgon Housec/o Nobel House17, Smith SquareSWIP 3JR LondonTel: +44 (171) 238 6187Fax: +44 (171) 238 5472Email: c. b.walters@fsci. mafftgov. uk

Dr. B. Watkins QuantiSci LtdChiltern House,45 Station Rd.RG9 1AT Henley-on-Thames, OxfordshireTel: +44 1491 410474Fax +44 1491 576916Email: biomass~quantisci.co.uk

Mr. L. Watts National Radiological Protection Board (NRPB)ChiltonOidcotOX 1I ORQ OxonTel: +44 (1235) 831 600Fax: +44 (1235) 833 891E-mail:

Mr. R. Wilmot Galson Sciences Ltd.5 Grosvenor House, Melton Rd.LEIS 6AX Oakham, RutlandTel: +44 1572 770 649Fax: +44 1572 770 650E-mail:

6

Mr. R. Yearsley Environment AgencySteel House11 Tothill StreetSW1H 9NF LondonTel: +44 (0171)664 6700Fax: +44 (0171) 664 6833Email: roger.yearsleyienvironment-agency.gov.uk

United States of AmericaDr. J. Kessler Manager, Electric Power Research Institute

3412 Hillview Ave.P.O.Box 10412CA 94304-1395 Palo AltoTel: +1 (650) 855 2069Fax: +1 (650) 855 2774Email: jkessler~epri.com

Ms. L. Lehman President, Technical & regulatory Evaluations Group. Inc (T-Reg)13231 Henning Circle, NE55372 Prior Lake, MNTel: +1 612-496-0594Fax: +1 612-496-2097Email: Illehman@aol.com

Mr. C. McKenney Division of Waste Management, Office of Nuclear Material Safety &SafeguardsU.S. Nuclear Regulatory Commission (USNRC)1717 H StreetMail Stop T7F-3DC 20555 WashingtonTel: +1 301 415 6663Fax: +1 301 415 5399Email: CAM1@NRC.GOV

Mr. J. Tappen Yucca Mountain Site Characterisation Office, M&OScience Applications International Corporation (SAIC)1180 Town Center DriveNV 89134 Las VegasTel: +1 702 295 5027Fax: +1 702 295 5223Email: jeff tappengymp.gov

Dr. C. Yu Building 900Argonne National Laboratory9700 South Cass AvenueIL 60439 Argonne, IllinoisTel: +1 (708) 252 5589Fax: +1 (708) 252 4624Email: CYU@ANL.GOV

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5. Example Assessment Contexts

The following example contexts are listed in order of increasing complexity. Theexamples have been generalised to be as widely applicable as possible. In the case ofspecific assessments for an individual site/waste repository, the assessment contextcould be more highly detailed, though this ould depend on the assessment purpose,which is part of the context. The purposes listed below are not to be consideredinclusive of all possible uses of the conceptual and mathematical models developed byBIOMASS based on the examples.

Additionally, as stated previously in the document, each of the decisions for theassessment components should be justified for the specific assessment context, based onnational standards and guidance, site-specific information, external needs. Someassessment components may be general assumptions to be applied to the developmentof conceptual and mathematical models, such as exposure pathways being limited todrinking water only because of the lack of site data. These assumptions should beexplained and justified in as much detail as possible and reasons could include lack of sitedata (especially early in repository development) or lack of definitive regulations orguidance. Because the following examples are generalised examples, they lack many ofthe detailed justifications necessary in a specific national assessment. Where possible theassessment components have been justified.

Use of these models will need to be justified for each specific assessment but the concepts,even if not directly applicable, should be valuable examples in developing specificassessment contexts (and based on the work in other task groups, conceptual andmathematical models) for any long-term assessment. The biosphere systems andpertinent databases to be derived based on the example assessment contexts, by the otherBIOMASS task groups, will be documented carefully, in order for others to facilatecomparisons of the FEPs, parameter values, and assumptions with those appropriate ona national site-specific conditions.

5.1 Drinking Water Well

In many cases, it is desired to have a very simple biosphere model that is still an indicatorof repository performance. Such models can be useful in early repository developmentstages such as proof of concept and site selection, where pertinent site-specific data maybe lacking, or in intercomparisons between national programs. The following exampleassessment context is based on the external need for a simple but reasonably conservativebiosphere model. A general assessment assumption is because of the lack of site data,human activities will be limited to exposure to radionuclides through drinking water. As aconservative assumption, it will be assumed that the individual abstracts water directly fromthe contaminant plume in the aquifer and there will not be any monitoring or watertreatment. Because most of the participants in BIOMASS have noted a high degree ofinterest in deep disposal of long-lived radionuclides, the repository type and keyradionuclides are based on this interest. The drinking water well example, because it canbe useful at many stages of the repository development, will consider the full suite of

2

radionuclides. Additionally, because of wide interest, the climate is assumed to betemperate, and the repository is situated inland.

Example I - Drinking Water Well

Purpose:

Endpoints:

Repository Type:Site Context:

Source Term:Geo/Biosphere Interface:

Time Frame:Societal Assumptions:

Regulator/Scientific ConfidenceProof of ConceptGuide Site SelectionsGuide Research Priorities (Geosphere)Individual Dose(Reasonable assumptions - not highly pessimistic)Deep disposal of long-lived radionuclidesTemperate climate, no biosphere evolution assumed, aquiferplume at accessible depth, inland repository, assumed soilsare not indicative of farmingWide range of radionuclidesWell intruding into aquifer plume limited to an abstraction rateconsistent with household use. Groundwater concentrationsof radionuclides (including relevant daughter products)provided by geosphere transport models.Peak dose (maximum time frame 1.OE+06 yrs)Assumed for simplicity that exposed group uses groundwaterfor drinking water only. No monitoring of drinking water.

5.2 Agricultural Exposure

A slightly more complex assessment, but still generically applicable to many different sites,is to include not only drinking water but other exposure pathways present in an agrariansociety using contaminated water. Because it is wanted to apply to many purposes,especially at early time steps when site data is lacking, a temperate biosphere is assumedwith no biosphere evolu',i.. The endpoint of concern is the individual dose, usingreasonable assumptions and data on agrarian societies in temperate environments, to theaverage member of the critical group. To facilitate comparisons between results ofexample 1 and these results, two examples are included. The main difference is thegeosphere/biosphere interface. In example 2A, the individual from example 1 is locatedwhere it is possible to farm and the water for all needs (e.g., drinking, household uses,krigation, etc.) is supplied through the water well(s) in the aquifer. In example 2B, theindividual is placed in a valley with abundant water resources (lake or river) but can stillhave a well for drinking purposes only. The water resources are sufficient to supply waterfor allbuses (including drinking water).

Example 2A - Well Water Abstraction

Purpose: Regulator/Scientific ConfidenceProof of Concept

3

Endpoints:

Repository Type:Site Context:

Source Term:GeofBiosphere Interface:

Time Frame:Societal Assumptions:

Guide Site SelectionGuide Research Priorities (Geosphere)Individual Dose to average member of the critical group(Reasonable assumptions - not highly pessimistic)Deep disposal of long-lived radionuclidesTemperate climate, no biosphere evolution assumed, aquiferplume at accessible depth, inland repository, assumed soilsare indicative of farming.Wide range of radionuclidesWell intruding into aquifer plume limited to an abstraction rateconsistent with full range of water use. Groundwaterconcentrations of radionuclides (including relevant daughterproducts) provided by geosphere transport models.Peak dose (maximum time frame 1.OE+06 yrs)Agrarian society with well water being the source of potablewater, irrigation water, and water for other uses. No monitoringof water supplies.

Example 2B - Well and Surface Water Abstraction

Purpose:

Endpoints:

Repository Type:Site Context:

Source Term:Geo/Biosphere Interfaces:

Time Frame:Societal Assumptions:

Regulator/Scientific ConfidenceProof of ConceptGuide Site SelectionGuide Research Priorities (Geosphere)Individual Dose(Reasonable assumptions - not highly pessimistic)Deep disposal of long-lived radionuclidesTemperate climate, no biosphere evolution assumed, aquiferplume at accessible depth, inland repository, assumed soilsare indicative of farming,valley with plentiful surface waterresources (e.g. river or lakes).Wide range of radionuclidesWell intruding into aquifer plume limited to an abstraction rateconsistent with drinking water and household uses. Surfacewater bodies have plentiful volume to provide for all wateruses. Groundwater discharges into surface water bodies andterrestrial areas. Groundwater concentrations of radionuclides(including relevant daughter products) provided by geospheretransport models.Peak dose (maximum time frame 1.OE+06 yrs)Agrarian society. No monitoring of water supplies. Drinkingwater supplied either from well or surface water body.

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5.3 Discrete Biosphere Evolution and Multiple Endpoints

The next level of complexity is to include biosphere evolution into the assessment. It canbe visualised that models (both conceptual and mathematical) can be applicable in a widerange of purposes from demonstrating compliance to guiding site selection, especially if thenumber of sites are limited and are expected to have similar biosphere evolutions. Thesemore complex models can also focus on determining not only individual dose to theaverage member of the critical group but also to other specific exposure groups that maybe of concern to either the scientific community or public. Additionally, it is assumed thatit would be useful to calculate various environmental concentrations. Two examples areproposed, both based on example 2B. Example 3A would have a single discrete biosphereevolution at I 04 years. Example 3B would consider multiple discrete biosphere evolutionsteps, including the cyclic nature of biosphere evolution.

Example 3A - Two-staged biosphere evolution

Purpose:

Endpoints:

Repository Type:Site Context:

Source Term:Geo/Biosphere Interfaces:

time Frame:Societal Assumptions:

Demostrate ComplianceRegulator/ScientificlPublic ConfidenceGuide Site SelectionGuide Research Priorities (Biosphere)Individual Dose to average member of critical group(Reasonable assumptions - not highly pessimistic)Individual Dose to other applicable exposure groupEnvironmental concentrationsDeep disposal of long-lived radionuclidesTemperate climate, single biosphere evolution assumed at 1 04yrs, aquifer plume at accessible depth, inland repository,assumed soils are indicative of farming, valley with plentifulsurface water resources (lake or river).1-129, Np-237+daughters, Tc-99Well intruding into aquifer plume limited to an abstraction rateconsistent with drinking water and household uses. Surfacewater bodies have plentiful volume to provide for all wateruses. Groundwater discharges into surface water bodies andterrestrial environment. Groundwater concentrations ofradionuclides (including relevant daughter products) providedby geosphere transport models.Peak dose (maximum time frame I.OE+06 yrs)Agrarian society. No monitoring of water supplies. Drinkingwater supplied either from well or surface water body. Societywill change as necessary to accommodate biosphere evolution.

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Examole 3B- Discrete biosohere evolution

Purpose:

Endpoints:

Repository Type:Site Context:

Source Term:Geo/Biosphere Interfaces:

Time Frame:Societal Assumptions:

Demonstrate ComplianceRegulator/Scientific/Public ConfidenceGuide Site SelectionGuide Research Priorities (Biosphere)Individual Dose to average member of critical group(Reasonable assumptions - not highly pessimistic)Individual Dose to other applicable exposure groupEnvironmental concentrationsDeep disposal of long-lived radionuclidesTemperate climate, discrete biosphere evolution, aquiferplume at accessible depth, inland repository, assumed soilsare indicative of farming, valley with plentiful surfacewater resources (lake or river).1-129, Np-237+daughters, Tc-99Well intruding into aquifer plume limited to an abstraction rateconsistent with drinking water and household uses. Surfacewater bodies have plentiful volume to provide for all wateruses. Groundwater discharges into surface water bodies andterrestrial environment. Groundwater concentrations ofradionuclides (including relevant daughter products) providedby geosphere transport models.Peak dose (maximum time frame 1.OE+06 yrs)Agrarian society. No monitoring of water supplies. Drinkingwater supplied either from well or surface water body. Societywill change as necessary to accomodate biosphere evolution.

5.4 Continuous Biosphere Evolution

Examples of assessment contexts that most likely result in highly complex modelling areincluded below. These examples are more complex versions of section 5.3 examples. Inthe following examples, the assessment context includes the need for continuous modellingof biosphere evolution (either with only 2 biospheres (example 4A) or continuous modellingof range of plausible future biosphere evolutions) and the need to calculate doses to non-human biota. While the inclusion of non-human biota is not necessarily complex, the lackof quanitative standards for comparison makes judging the adequacy of the resultingmodels (both conceptual and mathematical) difficult.

Example 4A - Two Biospheres

Purpose: Regulatory ComplianceRegulator/ScientificlPublic ConfidenceGuide Research Priorities (Biosphere)Guide Site Selection

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Endpoints: Individual Dose to average member of critical group(Reasonable assumptions - not highly pessimistic)Individual Dose to other applicable exposure groupEnvironmental concentrationsDoses to non-human biota

Repository Type: Deep disposal of long-lived radionuclidesSite Context: Temperate climate, continuous biosphere evolution between

current biosphere and "evolved" biosphere at -IO' yrs, aquiferplume at accessible depth, inland repository assumed soilsare indicative of farming, valley with plentiful surface waterresources (lake or river).

Source Term: 1-129, Np-237+daughters, Tc-99Geo/Biosphere Interfaces: Well intruding into aquifer plume limited to an abstraction rate

consistent with drinking water and household uses. Surfacewater bodies have plentiful volume to provide for all wateruses. Groundwater discharges into surface water bodies andterrestrial environment. Groundwater concentrations ofradionuclides (including relevant daughter products) providedby geosphere transport models.

Time Frame: Peak dose (maximum time frame I .OE+06 yrs)Societal Assumptions: Agrarian society. No monitoring of water supplies.

Drinking water supplied either from well or surface waterbody. Society will change as necessary to accomodatebiosphere evolution.

Example 4B - Complete Cycling

Purpose: Regulatory ComplianceRegulator/Scientific/Public ConfidenceGuide Research Priorities (Biosphere)-uide Site Selection

Endpoints: Individual Dose to average member of critical group(Reasonable assumptions - not highly pessimistic)Individual Dose to other applicable exposure groupEnvironmental concentrationsDoses to non-human biota

Repository Type: Deep disposal of long-lived radionuclidesSite Context: Temperate climate, continuous biosphere evolution, aquifer

plume at accessible depth, inland repository, assumed soilsare indicative of farming, valley with plentiful surface waterresources (lake or river).

Source Term: 1-129, Np-237+daughters, Tc-99Geo/Biosphere Interfaces: Well intruding into aquifer plume limited to an abstraction rate

consistent with drinking water and household uses. Surfacewater bodies have plentiful volume to provide for all water

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uses. Groundwater discharges into surface water bodies andterrestrial environments. Groundwater concentrations ofradionuclides (including relevant daughter products) providedby geosphere transport models.Peak dose (maximum time frame 1.OE+06 yrs)Agrarian society. No monitoring of water supplies. Drinkingwater supplied either from well or surface water body. Societywill change as necessary to accomodate biosphere evolution.

Time Frame:Societal Assumptions: