An independent evaluation of the proposed EPA environmental standard for high level radioactive waste disposal

The Environmental Protection Agency has issued for public comment an environmental protection standard for high-level radioactive waste, which contains numerical limits for radionuclides reaching the ''accessible environment'' from a geologic repository over a period of 10,000 years. These release limits are derived from the basic criterion that the releases from a repository containing 100,000 metric tons of heavy metal (MTHM) shall result in no more than 1000 fatal cancers in the world-wide population over the 10,000 years This paper examines the framework of logic and assumptions used by the EPA staff in establishing the standard and in deriving the numerical release limits. It is concluded that several of the assumptions and parameters used to derive the numerical release limits are subject to considerable technical controversy. The propose standard may offer advantages to the Department of Energy over other possible forms of a standard for the demonstration of compliance, in that calculations of doses are not necessary. However, it is a matter of concern that assessments intended to evaluate isolation system designs (and their performance) against the proposed EPA standard may not provide a complete understanding of the overall system behavior