Regulatory Perspectives on Plutonium Oxidation States at the Waste Isolation Pilot Plant, Carlsbad, New Mexico, USA

摘要

EPA’s technical review process examines both whathas changed since the previous recertification and what hasnot. The current oxidation state assumptions for the WIPPhave remained unchanged since the 1990s CCA, thoughEPA’s review of the literature since 1996 indicates evidenceto place more importance on the stability of Pu~（3+）. Therefore,EPA believes there is justification to update the oxidationstate implementation from a 50/50 partitioning to one thatplaces more emphasis on Pu~ （3+）. This evidence also suggests aneed to reexamine the actinide oxidation states assumptionsand to obtain new recommendations on its implementationvia an independent technical review.