2011 Annual Public Meeting of the Progress on Proposed Project Chernobyl Cooling Pond as Case Study for Improving the Scientific Basis for Multimedia Environmental Modeling, Risk Assessment, and Database Development 2011 Annual Public Meeting of the Interagency Steering Committee on Multimedia Environmental Modeling (ISCMEM) November 28 - 29, 2011

Outline Timeline of the Proposal Preparation and Overall Objective of the Case Study Brief Information about the Chernobyl Cooling Pond Benefits and Relevance to the U.S. Federal Agencies and International Agencies Missions Information about the International Meeting on ”Feasibility Study of the Chernobyl Cooling Pond Decommissioning and Remediation” organized by the ChNPP Administration IAEA Involvement and Recommendations Potential Case Studies at DOE sites Project Organization

Timeline February 2010 – Preliminary discussion of the proposal to NRC Staff April 10, 2010 – Submitted 1st draft of the proposal to ISCMEM June 10 and September 8, 2010 – Presentation to ISCMEM Working Group 2 September 16, 2010 – Presentation to the ISCMEM Annual Meeting, Vicksburg, MS July 29, 2010 – Submitted a revised proposal which was uploaded to the EPA Integrated Environmental Modeling Hub iemHUB: http://iemhub.org/ August 3, 2011– Presentation to joint meeting of ISCMEM WGs 1, 2, 3 and 4 November 29, 2011 – Steering Committee vote to approve 1st ISCMEM international test case

Overall Objective of the Case Study Provide an opportunity for Federal Agencies to review and select information from the long-term observations at the Chernobyl Cooling Pond and the surrounding watersheds, which can be used as an analogue for improving the scientific basis and developing linkages, in the areas of multimedia environmental modeling, focusing on: parameter estimation and modeling uncertainty, site characterization and monitoring, human health risk and safety, loss of natural resources, cleanup, and evaluation of remediation technologies on a large scale.

137Cs Fallout in Ukraine, Belorussia, Russia Chernobyl Cooling Pond Cs-137 ChNPP Pripyat River Sr-90 Area ~ 23 km2 , ~ 108 m3 of water Water is pumped from the Pripyat River to the Cooling Pond The Chernobyl cooling pond is an artificial body of water that was created to cool down the heat exchangers of four nuclear reactor units at the Chernobyl Nuclear Power Plant. Its areal extent is ~23 sq km. To maintain the water level, water is pumped from the Pripyat River to the Cooling Pond. As a result of the Chernobyl accident, the cooling pond was exposed to extremely high levels of contamination. You can see that from these maps, that the pond is in the middle of the contaminant plume. Moreover, heavily contaminated water from the reactor basement was discharded to the pond, and even now there are routine releases of contaminated water into the pond. Sources of Contamination Dispersed fuel particles Heavily contaminated water from the reactor basement and soils. Total radioactivity >200 TBq, including 137Cs-80%, 90Sr-10%, 239,240, 241Pu-10% Routine releases of contaminated water into the pond

Chernobyl Cooling Pond Radio-Ecological Study Complete remediation of the Cooling Pond would significantly damage the ecosystem whilst not significantly reducing doses; Phytostabilisation of some small areas may be worthwhile; Drawdown of water level should be as slow as practicable; Monitored natural attenuation is the most environmentally sound remediation option. RESRAD-BIOTA: A Tool for Implementing a Graded Approach to Biota Dose Evaluation (Argonne Lab) Radioecological studies of potential consequences of the pond decommissioning conducted by a group of Europian scientific organizations showed that: Pond drawdown will negatively impact biodiversity of fish Complete remediation of the Cooling Pond would significantly damage the ecosystem whilst not significantly reducing doses; Phytostabilisation of some small areas may be worthwhile; Drawdown of water level should be as slow as practicable; Monitored natural attenuation is the most environmentally sound remediation option Additional more comprehensive research studies, including monitoring and modeling, are needed to develop a roadmap of the CHCP decomisisoning and remediation. Jim Smith -- School of Earth and Environmental Sciences, University of Portsmouth, UK, Oleg Voitsekhovich – Ukrainian Hydrometeorological Institute, Kiev, Ukraine EU (INTAS); Royal Society AQUASCOPE--Aquatic modeling study AQUACURE--Countermeasures EU INCO – Copernicus

Expected exposed area 58%. Chernobyl Cooling Pond Decommissioning is an Opportunity to Study the Effect of Changes in Climatic Conditions on Contaminated Water Bodies Normal scenario Dry scenario Modeling for different climatic scenarios -- averaged and dry conditions, showed that after the stoppage of pumping of water into the pond, some residual water bodies will remain, and the areal extent of exposed sediments will vary from ~13 to more than 18 sq.km, depending on climatic conditions. Expected exposed area 58%. 137Cs- 78%, 90Sr--74%, Pu-85% will remain under water in bottom sediments. Expected exposed area 80% Bugai et al. 2006

Radionuclide Transport Processes in the Chernobyl Cooling Pond Microbial communities Suspended sediments Advection Uptake Adsorption Radionuclides in suspended sediments Diffusion/Dispersion Dissolved radionuclides Desorption Resuspension Adsorption Desorption R/N transport processes in a water-sediments system include advection, adsorption, desorption, and exchange with bottom sediments. Here the presence of hot particles will play a significant role. Sedimentation Radionuclides in bottom sediments Hot particles Modified after M.Zheleznyak

Case Studies Stemming from the Chernobyl Cooling Pond Monitoring and Modeling (1) Evaluation of hydrologic and geochemical processes for unsaturated-saturated soils and bottom sediments; (2) Modeling of coupled hydrological and biogeochemical processes, including parameter estimation, aleatory, epistemic, and scenario uncertainties; (3) Design and implementation of appropriate site characterization and monitoring techniques for highly contaminated soils and groundwater - geophysical monitoring, natural and radioactive isotopic methods, remote sensing; (4) Assessing the efficacy of different remediation approaches including monitored natural attenuation (MNA). (5) DOE ASCEM project, NRC/EPA/USGS Integrated Environmental Modeling.

Benefits and Relevance to the U. S Benefits and Relevance to the U.S. Federal and International Agencies Missions If endorsed by ISCMEM, Chernobyl Cooling Pond International case study will provide the opportunity for collaboration between different Federal agencies, and international organizations in accomplishing their missions associated with predicting the post-accident, long-term behavior of radionuclides and remediation of radioactively contaminated sites. US NRC—ensure adequate protection of public health and safety, and to protect the environment; US DOE and DoD—advance science, engineering, and cleanup technologies to help ensure that it meets its national environmental cleanup strategic goals; testing high performance computing capabilities, parameter estimation, UQ, data management, visualization; US EPA—protect human health and the environment; US Army Corps of Engineering – evaluate watershed modeling codes, and USGS—provide information to effectively and responsibly utilize natural resources, and to protect the health, safety, and well-being of the people. IAEA – develop recommendations for member states; European Network of Excellence in Radioecology (STAR): Chernobyl observatory.

Meeting on ”Feasibility Study of the Chernobyl Cooling Pond Decommissioning and Remediation” organized by the ChNPP Administration (Sept 2011) Goals of the Meeting: Provide the background information and direct the scientific organizations involved in the project. This project on the ChNPP Cooling Pond decommissioning was stipulated by the Law of Ukraine 886-VI “On National Program of Chernobyl NPP Decommissioning and Shelter object transformation into environmentally safe system,” starting January 1, 2010. ChNPP Administration will fund the project. Partial funding will be provided by IAEA. Tender to select a company to perform the Feasibility Study was announced at the meeting.

Meeting on ”Feasibility Study of the Chernobyl Cooling Pond Decommissioning and Remediation” organized the ChNPP Administration (Sept 2011)   Ukrainian Organizations Involved in the Project: State Special Enterprise “Chernobyl NPP” Institute of Safety Problems of Nuclear Power Plants of the National Academy of Sciences of Ukraine Ukrainian Scientific-Research Hydrometeorological Institute Ukrainian Scientific-Research Institute of Agricultural Radioecology Institute of Geological Sciences of the National Academy of Sciences of Ukraine, Institute of Mathematical Machines and Systems of the National Academy of Sciences of Ukraine Institute of Hydrobiology of the National Academy of Sciences of Ukraine Scientific-Research Institute of Radiation Protection Chernobyl Center for Nuclear Safety, Radioactive Waste and Radioecology, and International Radioecology Laboratory State Specialized Scientific and Industrial Enterprise Chernobyl Radioecological Center (GSNPP ECOCENTER)

The Most Critical Problem is Monitoring During the Water Level Drawdown Monitoring System: 1 – Center 2 – Adjacent area 3 – Bottom sediments Monitoring Media: Surface water Groundwater Hydrobiota Precipitation Near-surface atmosphere Landscape

IAEA Involvement and Recommendations IAEA supported three missions of international technical experts to Chernobyl (October 2009, July 2010, September 2011) to initiate the development of a roadmap and modeling of groundwater flow and contaminant transport for the feasibility study of the Chernobyl Cooling Pond decommissioning and remediation IAEA Point of Contact: Horst Monken-Fernandes, IAEA Waste Technology Section

IAEA’s List of Suggested Tasks Collate existing data of monitoring, modeling and risk assessment of the Cooling Pond and groundwater system. Consultation with regulators and stakeholders. Key objectives: agree on remediation endpoints, gaps in data/risk assessment and action plan Identify gaps in monitoring and modeling data and risk assessment. Conduct research to address gaps. Develop an improved monitoring plan and conduct an initial experimental 1-2 m drawdown— Stage 1 of Feasibility Study. Complete experimental drawdown and provide data for Stage 2 Feasibility Study Regulatory approval for complete, staged drawdown NO YES Finish installation of a monitoring system prior to full, staged drawdown. Begin full drawdown. IAEA report, 2009

List of Potential Projects in Support of Cooling Pond Decommissioning and Remediation Tentative duration 1. Data collation and development of GIS/Database/Data Management System 6 months 2. Risk assessment research, with focusing on fire risk/wind resuspension, flooding, dam failure and surface water-groundwater flow and radionuclide transport modeling and uncertainty evaluation. 2 years 3. Experimental (pilot) drawdown project and associated monitoring and modeling; improved experimental/modeling assessment of remediation technologies and monitored natural attenuation 4. Planning, testing and installation of an upgraded adaptive monitoring system, including a timeline of expanding the system as the Cooling Pond water level declines. 2-3 years 5. Monitoring and risk assessment, including modeling of impacts of drawdown on ecology and radioecology of the area surrounding Cooling Pond, Chernobyl Exclusion Zone, and the Pripyat’ River System. 3-5 years IAEA report, 2009, with changes.

Savannah River PAR Pond Case Studies to Test DOE Field Remotely Operated Monitoring Techniques Oak Ridge Reservation--White Oak Lake Savannah River PAR Pond Constructed in 1958 as a Cooling Pond for the Savannah River Site's P and R Reactors After the water level drawdown in 1991: Exposed 5.3 km2 of contaminated sediments. Mobility of the radionuclides was much greater than expected (Hinton et al. 1999; Whicker et al. 1999). Cs-137 concentrations increased, probably resulting from the Cs-137 increase in sediments. Sedimentation rates and water turbidity increased due to erosion processes. DOE EM Points of Contact: Kurt Gerdes, DOE EM-32, Director, Kurt.Gerdes@em.doe.gov Mark Williamson, DOE EM-32, ASCEM Lead, Mark.Williamson@em.doe.gov

Case Studies to Test DOE Field Remotely Operated Monitoring Techniques INL Soil and Surface Assay Systems for Gamma, Beta, and Alpha Radiation Sources Savannah River Site ADCON Telemetry-a real-time soil moisture monitoring system (D-Area Phytoremediation). FDTAS-tritium analysis system in surface and groundwater in near real- time. Sol-Gel Indicators for Process and Environmental Measurements .

Project Organization Lead Agencies and Coordinating Managers: DOE-EM—Kurt Gerdes and Skip Chamberlain NRC—Thomas J. Nicholson, Ralph E. Cady, Mark Fuhrman Subject Area: Modeling and Uncertainty Evaluation, Parameter Estimation, Monitoring, and Risk Analysis USA Agencies Potentially Interested in the Project: DOE, EPA, NRCS, DOD, USGS, US Army Corps. International Organizations Potentially Interested in the Project: International Atomic Energy Agency (IAEA), Institute for Radiation Protection (France). Ukrainian Organizations Involved in the Chernobyl Cooling Pond Studies: Administration of the Chernobyl Exclusion Zone, Chernobyl Nuclear Power Plant, National Academy of Sciences of Ukraine (Institute of Geological Sciences, Institute of Mathematical Machines and Systems, Hydrobiological Institute, Institute of of Safety Problems of Nuclear Power Plants), State Nuclear Regulatory Committee of Ukraine, Radioecology Center, State Scientific-Technical Centre Nuclear Radiation Safety (SSTC NRS), Hydrometeorological Institute. Data/reports/publications exchange and coordination – EPA Integrated Environmental Modeling Hub (iemHUB) – http://iemhub.org/, Gene Whelan, US EPA.