Biosphere FEP list development specific to Yucca Mountain

Performance assessment (PA) methodologies for repositories for high-level waste (HLW) involve the collation and analysis of a wide variety of information obtained from many sources and involving many scientific and technical disciplines. The information is commonly described as Features, Events and Processes, or FEP`s. Coherent application of all this information to the assessment has been a major component of methodology development. As a recent example, see the Swedish Nuclear Power Inspectorate report on systems analysis, scenario construction and consequence analysis definition for SITE 94. This paper summarizes work being performed to develop a list of FEP`s relevant to the biosphere component of a PA for HLW disposal at Yucca Mountain.