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SCIENCE for EM Cleanup?. Kevin D. Crowley Director Board on Radioactive Waste Management The National Academies. National Academies’ EM Science Program Studies. Photo credits: National Academies Press. + One more report to come (Nuclear Materials).
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SCIENCE for EM Cleanup? Kevin D. Crowley Director Board on Radioactive Waste Management The National Academies
National Academies’ EM Science Program Studies Photo credits: National Academies Press + One more report to come (Nuclear Materials) The opinions expressed in this presentation are personal views informed by this work Presentation to BERAC, December 4, 2002
“Intractable” Problems Defined It depends on who the audience is … • Scientist: Knowledge/technology does not exist to address the problem • Policymaker:Problem cannot be addressed within available time or budget constraints • Regulator:Problem cannot be addressed without exposing workers/public to unacceptable risks or violating other regulatory requirements … Science can help to address all three types of problems Presentation to BERAC, December 4, 2002
The DOE Nuclear Weapons Complex ... Over 100 sites & 5,000 facilities 5 “high-cost” sites: Hanford INEEL NTS Oak Ridge Savannah River Figure credit: American Scientist Presentation to BERAC, December 4, 2002
Some Basic Facts About Cleanup • It’s not about complete contaminant removal … • Goal is to put waste/contaminants into a more stable form—not to remediate sites for unrestricted release • Over 100 sites will not be cleaned up completely—some will require indefinite stewardship • Work on most difficult problems has been postponed • It’s not about science either … • Program is driven by over 7,0000 milestones and is budget constrained • There is a strong bias toward baseline approaches • There is “never enough time” to do the necessary science Presentation to BERAC, December 4, 2002
Cleanup Challenges: Hanford Example Large waste volumes Diverse physical/chemical forms Radioactive and toxic waste Poor storage conditions Environmental releases Figure credits: American Scientist Presentation to BERAC, December 4, 2002
Accelerated Cleanup = Less Time For Science • Goals of DOE’s Accelerated Clean-Up Initiative: • Reduce the $220B-$300B program cost by $100B • Reduce program completion by 40 years, from 2070 to 2030 • Accelerate shipment of waste to disposal sites, and also reduce amount of waste to be shipped. • Focus science and technology on “critical path” (to site closure) and “high-risk” problems • Eleven sites have signed letters of intent to accelerate cleanup: http://www.em.doe.gov/cri.html • Detailed plans are under development • Bottom Line: There will be less time for new science to be developed and used Presentation to BERAC, December 4, 2002
Intractable Problems … A 30,000’ View Problem #1: High-Level Waste • 340,000 cubic meters, 2.4 billion curies, ~$55B (DOE) • Stored in underground tanks at Hanford (177) and Savannah River (49) and in stainless steel bin-sets/concrete vaults (5) at INEEL • INEEL waste is in solid form in robust storage • Hanford and Savannah River waste is in liquid/solid form in aging underground tanks • 76 tanks (67 Hanford, 9 Savannah River) are known “leakers” • Some tanks are potentially vulnerable to accidents, acts of God, and terrorism Presentation to BERAC, December 4, 2002
HLW: Should it all be retrieved? Will retrieval lead to additional environmental contamination? Technical Challenges: Characterization Retrieval Immobilization Photo credits: Bottom: DOE-Hanford; Top: Pacific Northwest National Laboratory
HLW Tanks: How clean is clean enough? How should tanks be dispositioned? Photo credit: Pacific Northwest National Laboratory Photo credit: Pacific Northwest National Laboratory Technical Challenges: Characterization Contaminant stabilization Presentation to BERAC, December 4, 2002 Figure credit: DOE-Hanford
Intractable Problems, continued Problem #2: Buried Waste • 6.2 million cubic meters, 50 million curies, $??? • TRU, LLW, hazardous waste • Solids & liquids • Haphazard shallow-land burial (most < 30 m depth) • Hundreds of sites across the complex • Poor records of locations and contents • Many burial sites are leaking contaminants to the environment Presentation to BERAC, December 4, 2002
Buried waste: Remove or stabilize in place? Photo/figure credits: Left and center: DOE-Savannah River Upper right: Idaho National Engineering and Environmental Laboratory Technical challenges: Characterization Contaminant stabilization Remediation Monitoring
Intractable Problems, continued Problem #3: Contaminated Soil/Groundwater • 29 million cubic meters contaminated soil • 36 million cubic meters of mill tailings • 4.7 billion cubic meters contaminated groundwater • Chemicals, metals, and radionuclides • Thousands of release sites across the complex • Contaminant concentrations may exceed drinking water standards at some sites for hundreds of years • Complete contaminant stabilization/removal not feasible with current technologies • Perpetual monitoring, periodic re-remediation? Presentation to BERAC, December 4, 2002
Soil/GW contamination: Where? How much? How to remediate? Technical challenges: Characterization Stabilization Remediation Monitoring Photo credits: Upper Right: DOE-Hanford Upper left: DOE-Savannah River Lower left: DOE-Oak Ridge
Honorable Mentions • Deactivation and Decommissioning: Expensive, time consuming, potentially hazardous to workers, but not intractable • Orphan Waste Streams & Materials (e.g., DU): These exist across the complex but are not long-term program “show-stoppers” • Radiation Effects: A good first-order understanding exists; research is not likely to lead to changes in standards in time to affect the clean-up program • Long-Term Stewardship: A potential “elephant in the living room,” especially if the clean-up program cuts corners; technical and institutional concerns Presentation to BERAC, December 4, 2002
Science: Needed for Cleanup • Solving problems associated with remediation baselines—but may not know what these are until failures occur (e.g., SRS alt. salt project) • Developing alternative approaches—e.g., new HLW forms that meet waste-acceptance criteria but can accommodate a wider range of waste compositions and loadings (reduce baseline plan for 19,000 HLW glass canisters @ $1M-$2M each) • Understanding the consequences of action or inaction—e.g., What happens if buried waste is left in place? What happens if HLW leaks into the subsurface during retrieval? Presentation to BERAC, December 4, 2002
Concluding Thoughts • What kind of a program does ERSD want to be? • A traditional bottoms-up DOE research program? • Or a top-down program that anticipates needs and is proactive in addressing them? • An anticipatory, proactive program needs to be inside the EM “fence” and in-synch with clean-up schedules and plans to be maximally effective • The challenge will be to incorporate the best of both top-down (program-driven) and bottoms-up (investigator-driven) approaches • Are there other research programs that can serve as guides for ERSD? Presentation to BERAC, December 4, 2002