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Uncertainties in Nuclear and Hazardous Waste Cleanup. Max S. Power Washington Department of Ecology Nuclear Waste Program April 1, 2003. Two Ways To Be Protective. Transform substance from hazardous to non-hazardous E.g. incineration, chemical treatment
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Uncertainties in Nuclear and Hazardous Waste Cleanup Max S. Power Washington Department of Ecology Nuclear Waste Program April 1, 2003
Two Ways To Be Protective • Transform substance from hazardous to non-hazardous • E.g. incineration, chemical treatment • Isolate substance from people and the environmental pathways to people • E.g. engineered land-fills, solidification to prevent leaching, geologic disposal
Bias for Newly-Generated Waste • Minimize hazardous waste generation • Reuse and recycle as much as possible • Treat to remove/reduce hazards • Minimize volume of residuals • Land disposal as a last resort • With lined facilities, leachate collection, etc
Bias for Waste Already Released to the Environment • Retrieve and treat • Restore affected land and/or water to “unrestricted use” • Treat residuals as newly-generated wastes
Existing Risk Risk Removal Legal Risk Standard Time Contamination Removal Case 1: Contamination Removed
Bias Against Long-Term Management • A result of uncertainty • Uncertainty about performance of materials • Uncertainty about durability of engineered structures • Uncertainty about durability and performance of human institutions • Underlies both “unrestricted use” for contaminated sites and deep geologic disposal for “hotter” nuclear waste
Existing Risk Removal Risk Legal Risk Standard Time Removal + Barriers and Controls Case 2: Contamination Removed + 1C & PC + Physical and Institutional Controls
Barriers & Controls • Engineered barriers • Liners and caps • Slurry walls, permeable barriers, grout, cryogenics • Institutional controls • Access restrictions • Use restrictions • E.g. deed restrictions, zoning, covenants, easements, drilling and digging prohibitions
What Can Be Done When . . . • It is not technically and/or economically feasible to transform the material? • It is not technically and/or economically feasible to retrieve all the hazard and treat and isolate it?
Attenuation • Rely on physical/chemical processes • E.g. radioactive decay, chemical oxidation • Depends on adequate characterization and understanding of processes • Monitor and wait, while relying on barriers and controls
Risk Controls + Attenuation Case 3: Controls until risk attenuates naturally Existing Risk Attenuation Institutional & Physical Controls + Physical and Institutional Controls Legal Risk Standard Time
Risk Controls Fail before Attenuation Case 4: Controls fail before risk attenuates Existing Risk Attenuation Institutional & Physical Controls Legal Risk Standard Time
Physical Barriers • Limited evidence on long-term performance • Regulations assume limited life (e.g. 30 years in RCRA) • Note: Our civilization uses barriers to keep people out of bad things; ancient civilizations used them to keep people out of treasure troves
Institutional Controls • Again, limited information on long-term performance • But the picture isn’t good. Zoning, deed restrictions (cf. Love Canal) are ephemeral • “Courthouses burn down.” • National Research Council Committee: IC’s will fail.
Reduce These Uncertainties By . . . • Providing information—and keeping it up-to-date • Revisiting past actions and monitoring performance • Providing resources to support these activities—and to respond if barriers or controls fail • Giving future people a stake
. . .and. . . • Redundancy, redundancy, redundancy • Information stashes • Accountable parties • Interested parties
. . . Or . . . • Deep geologic isolation • Waste Isolation Pilot Plant (New Mexico) for transuranic wastes • Yucca Mountain geologic repository • Note other past ideas • Deep seabed/subduction zone • Space ejection
Uncertainties Remain • But shift from concrete to calculational • “Numerical results of analyses extending to geological times, if presented without sufficient discussion of their significance, lead understandably to accusations of over-optimism, hubris, or even irrationality.” Yucca Mountain Repository1999 DOE Data Barrier Type Source: DOE Presentation to NWTRB, 1/25/99
For Additional Information • Washington Department of Ecology at: • http://www.ecy.wa.gov/ecyhome.html • Max Power at: • mpow461@ecy.wa.gov