Construction of complementary cumulative distribution functions for comparison with the EPA release limits for radioactive waste disposal

Abstract

The US Environmental Protection Agency (EPA) has promulgated a standard for the geologic disposal of radioactive waste (40 CFR 191) that requires the construction of a complementary cumulative distribution function (CCDF) that defines the probability of exceeding radionuclide releases of various sizes. Construction of this CCDF involves three interrelated activities: development of scenarios that describe the various disruptions that could occur at a waste disposal site, determination of probabilities for scenarios, and calculation of radionuclide releases for scenarios. The computational procedures being used in the performance assesement for the Waste Isolation Pilot Plant (WIPP) in southeastern New Mexico to bring these three activities together to produce the CCDF in 40 CFR 191 are described and illustrated with results obtained in a recent analysis.