1. Uncertainties in Nuclear and Hazardous Waste Cleanup Max S. Power Washington Department of Ecology Nuclear Waste Program April 1, 2003

2. 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

3. 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

4. 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

5. Contamination Removal Time Legal Risk Standard Existing Risk RiskRisk Removal Case 1: Contamination Removed

6. 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

7. Removal + Barriers and Controls Time Legal Risk Standard Existing Risk RiskRisk Removal Case 2: Contamination Removed + 1C & PC + Physical and Institutional Controls

8. 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

9. 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?

10. 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

11. Controls + Attenuation Time Legal Risk Standard Existing Risk RiskRisk Case 3: Controls until risk attenuates naturally + Physical and Institutional Controls Attenuation Institutional & Physical Controls

12. Controls Fail before Attenuation Time Legal Risk Standard Existing Risk RiskRisk Case 4: Controls fail before risk attenuates Attenuation Institutional & Physical Controls

13. 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

14. 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.

15. 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

16. ...and... Redundancy, redundancy, redundancy –Information stashes –Accountable parties –Interested parties

17. ... 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

18. 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.” Relative Contribution of Waste Isolation Barriers Percent of Capability 100% 80% Waste Package 99.7% Waste Package 60% 40% 20% 0% Spent Fuel Cladding 0.2% Yucca Mountain Overburden 0.09% Yucca Mountain Geology 0.008% Source: DOE Presentation to NWTRB, 1/25/99 Barrier Type Yucca Mountain Repository 1999 DOE Data

19. For Additional Information Washington Department of Ecology at: –http://www.ecy.wa.gov/ecyhome.htmlhttp://www.ecy.wa.gov/ecyhome.html Max Power at: –mpow461@ecy.wa.gov