High Performance Soft Magnetic Materials

Abstract

This paper describes the development and evolution of the Elec. Power Research Institute's (EPRI) post-closure dose assessment for potential releases of radionuclides from the proposed High Level Waste repository at Yucca Mountain. The starting point for this work was the 1995 publication of Tech. Bases for Yucca Mountain Stds. by the Commission on Geosciences, Environment and Resources of the National Research Council. This report proposed the development and application of an individual risk-based std. for releases from the repository to replace the existing one, which was based on radionuclide release limits. This in turn implied the development and application of methods to assess radiation doses to humans. Accordingly, EPRI produced a methodol. for such dose assessment as part of its Total System Performance Assessment program for the proposed Yucca Mountain repository site. The methodol. initially addressed releases via groundwater and then releases assocd. with extrusive igneous events. The methodol. was updated and applied over the following years to take account of regulatory developments, changes in ests. of the source term to the biosphere, peer review through international model comparison exercises, new site generic data, and new data concerning conditions at the point of compliance in Amargosa Valley. The main outputs were Biosphere Dose Conversion Factors, which relate radionuclide levels in environmental media to the annual individual doses to a member of a hypothetical crit. group and to the regulator-defined Reasonably Maximally Exposed Individual. Most recently, consideration has been given to uncertainty in the dose ests. based on a probabilistic anal. The paper provides a perspective on the evolution of the dose assessments in response to the developments listed above. [on SciFinder(R)]