K.L. Smith & C.A. Robinson Enviros Consulting Ltd & A.T.K. Ikonen, Posiva Oy

1. PROTECT Workshop, Jan 08

2. Demonstration Assessment of Doses to Non-human Biota from Olkiluoto Repository and General Considerations for Waste Repository Assessments K.L. Smith & C.A. Robinson Enviros Consulting Ltd & A.T.K. Ikonen, Posiva Oy PROTECT Workshop, Jan 08

3. Overview of presentation • General features of waste repository assessments • Demonstration assessment process for Olkiluoto repository (for Posiva Oy) • BIOPROTA Forum, January 07 • Future – current BIOPROTA plans PROTECT Workshop, Jan 08

4. Repository assessments: what makes them different? • Sub-surface source • Relative importance of different ecosystems and organisms • Significance of pathways of exposure • Timescales • Releases may be extended – may affect different generations • Evolution and climate change • Radionuclides • Long-lived • Key nuclides identified by BIOPROTA: Cl-36, Se-79, Tc-99, I-129, Pb-210, Po-210, Ra-226, Th-230, Np-237, and U-238 PROTECT Workshop, Jan 08

5. Assessment process • Problem formulation or setting the scope • Generic or specific (conservatism or realism) • Regulatory or research • Developing an approach • Information and methods available • Proportionality • A test case… PROTECT Workshop, Jan 08

6. Demonstration assessment for the waste repository at Olkiluoto • Decision in principle in favour of geological repository at Olkiluoto, southwest Finland • Disposal due to commence in 2020 • Regulated by the Radiation and Nuclear Safety Authority (STUK) • Posiva Oy responsible for development of repository • Broad safety case assessment (SCA) being developed PROTECT Workshop, Jan 08

7. Plan of ONKALO and repository Acknowledgement: plan from Posiva Oy website PROTECT Workshop, Jan 08

8. ONKALO construction and investigations Start of work September 2004 Drilling groutholes Acknowledgement: photos from Posiva Oy website: http://www.posiva.fi/englanti/ONKALO-esite_EN_140605.pdf PROTECT Workshop, Jan 08

9. Demonstration assessment process for the Olkiluoto repository Acknowledgement: photo from Posiva Oy website • Study objectives • Regulatory requirement • Choice of methodology • Test Case Assessment • Selection of assessment ecosystems and biota • Features of test case scenario • Methodology applied • Indicative results PROTECT Workshop, Jan 08

10. Regulatory Requirement ‘exposures shall remain clearly below the levels which, on the basis of the best available scientific knowledge, would cause decline in biodiversity or other significant detriment to any living population. Moreover, rare animals and plants as well as domestic animals shall not be exposed detrimentally as individuals’ (STUK, 2001, Document YVL 8.4) PROTECT Workshop, Jan 08

11. Regulatory Requirements • SCA therefore required to demonstrate (in addition to human protection criteria): • No decline in biodiversity of current living populations • No significant detriment to populations of fauna and flora • No detrimental effects on individuals of domestic animals and rare animals and plants • Some assessment assumptions defined: • Present kind of living populations; • Period of ‘several thousand years’ PROTECT Workshop, Jan 08

12. Choice of Assessment Methodology • Review of available and developing methodologies and applicability to the Olkiluoto site • Methods primarily based on a ‘reference organism’ approach and organisms representative of the local ecosystem • EPIC and FASSET/ERICA most comprehensive methodologies available • EPIC - arctic ecosystem likely to more closely represent local conditions (though data gaps remain); • FASSET/ERICA – provided data for a range of European ecosystems & wide range of reference organisms (tool not available at time of assessment). PROTECT Workshop, Jan 08

13. Marine/coastal areas Wetlands Forest/agriculture Environment around Olkiluoto • Island to southwest of Finnish mainland • Typical habitats (interwoven) • Shallow bays • Forests • Nutrient rich mires • Meadows • Sub-arctic climate • Under-going post-glacial land uplift PROTECT Workshop, Jan 08

14. Landscape predictions 5850 years AP Reference ecosystems selected for test case Marine/coastal Freshwater Wetland Agriculture/grassland Forest PROTECT Workshop, Jan 08

15. Interest species Identification of relevant biota • STUK requirement • Present kinds of living populations • Individuals of rare/sensitive species • Domestic animals • Generic organisms • Simple food webs • Interest species • Natura 2000 site descriptions • Agricultural statistics • Game statistics • Local knowledge – species of public interest PROTECT Workshop, Jan 08

16. Identification of relevant biota (2) • Sub-set of organisms selected and assigned to ecosystems • Occupancy within ecosystem compartments likely to result in increased dose • Demonstration of individual endpoints compared to population; • Migration between ecosystems (e.g. moose) • Organisms assigned, on basis of general biota characteristics: • Concentration ratios • Ellipsoid geometries (and associated dose conversion factors) • Occupancy factors (on or within soil, sediment & water) – taking account of climate • Migratory occupancy (between ecosystems) PROTECT Workshop, Jan 08

17. Test case organisms – Forest PROTECT Workshop, Jan 08

18. Migratory Interest creatures and occupancy assumptions PROTECT Workshop, Jan 08

19. Test case • PANDORA was used to (by Facilia) provide activity concentrations in water, soil and sediment as a function of time within defined biosphere compartments; • Scenario based on assumed source term locations normalised to total 1 Bq/y for each of the following radionuclides into the overall landscape: • Cl-36, Ni-59, Se-79, Tc-99, I-129, Cs-135, Po-210, Pb-210, Ra-226, Pu-239, U-234, U-238, Np-237. • The highest activity concentrations occurring at 10,000 years in each ecosystem type were identified for 1 Bq/y case; • Source term information for 10,000 years for full canister disintegration; • The maximum source term values (in 1 million years) also used for scoping. PROTECT Workshop, Jan 08

20. Freshwater - disappearing canister scenario PROTECT Workshop, Jan 08

21. Forest - disappearing canister scenario PROTECT Workshop, Jan 08

22. Maximum exposed creatures and principal dose contributors PROTECT Workshop, Jan 08

23. Highest dose under worst-case assumptions Even under maximising assumptions, doses do not approach those likely to cause harm to individuals or populations PROTECT Workshop, Jan 08

24. General methodological issues • Single stressor assessment (ionising radiation); • Chemical toxicity of radionuclides and of non-radioactive releases; • Assessment of population and community effects; • Population dynamics; • Interdependency of different organisms. • Dose rate benchmarks and effects analysis; • Limited data available for key creatures (e.g. for large mammals); PROTECT Workshop, Jan 08

25. General dose assessment issues • Generic equilibrium concentration ratios and distribution coefficients; • Limited database for some organisms and radionuclides; • Examples include large mammals (…) • Generic assumptions not necessarily applicable to all environments/organisms; • Dose conversion coefficients • Mammals • Dose rate weighting factors to allow for RBE of different radiation types PROTECT Workshop, Jan 08

26. Specific issues for long-term releases of long-lived radionuclides • Treatment of climate and landscape change; • Long-lived nuclide-specific data availability • Dealing with uncertainties, probabilistic assessment and communication; PROTECT Workshop, Jan 08

27. BIOPROTA • A forum to address uncertainties in the assessment of the radiological impact of releases of long lived radionuclides in to the biosphere (from solid waste disposal facilities) • Commonly focused projects: • efficient use of skills and resources • transparent and traceable basis for parameter value choice and wider interpretation of assessment information • Participants: • National authorities and agencies with responsibility for achieving safe and acceptable radioactive waste management, both regulators and operators • Enviros Secretariat www.bioprota.com PROTECT Workshop, Jan 08

28. ‘PROBIOTA’ Forum, January 2007 • Forum for the exchange information on the suitability of the current guidance and methods for non-human biota assessments to long-term assessments • Attended by 15 participants from 6 countries (operators and technical support organisations) Hosted by Posiva Oy, in Lappeenranta Finland PROTECT Workshop, Jan 08

29. ‘PROBIOTA’ Forum identified issues • Applicability of concentration ratios for assessing impacts to NHB • Dealing with site evolution over the timescales required for waste repository PAs and the effect on ecosystems • The value of sensitivity analysis to focus efforts • Dealing with synergistic interactions • Regulatory drivers (focus on present day knowledge and the applicability of this to future scenarios is not clear) • Communicating the results of NHB assessments • Value of follow-on workshops PROTECT Workshop, Jan 08

30. BIOPROTA - Proposal for sensitivity analysis • Evaluate the robustness of assessment data in relation to the key long-lived radionuclides applicable to deep geological disposal facilities; • Identify important data gaps and uncertainties related to biota dose assessment upon which future tasks may be identified; • Determine the impact of given release scenario assumptions and climate variations on calculated dose rate; • Evaluate the potential range of parameter values used in the assessment, the availability and ‘robustness’ of data; • Undertake a sensitivity analysis to identify the parameters and uncertainties that contribute most significantly to the overall results; • Perform a knowledge quality assessment to identify key gaps in data and understanding; PROTECT Workshop, Jan 08