THE DEVELOPMENT OF THE YUCCA MOUNTAIN PROJECT FEATURE, EVENT, AND PROCESS (FEP) DATABASE

A Total System Performance Assessment for Site Recommendation (TSPA-SR) has recently been completed (CRWMS M&O, 2000b) for the potential high-level waste repository at the Yucca Mountain site. The TSPA-SR is an integrated model of scenarios and processes relevant to the postclosure performance of the potential repository. The TSPA-SR scenarios and model components in turn include representations of all features, events, and processes (FEPs) identified as being relevant (i.e., screened in) for analysis. The process of identifying, classifying, and screening potentially relevant FEPs thus provides a critical foundation for scenario development and TSPA analyses for the Yucca Mountain site (Swift et al., 1999). The objectives of this paper are to describe (a) the identification and classification of the comprehensive list of FEPs potentially relevant to the postclosure performance of the potential Yucca Mountain repository, and (b) the development, structure, and use of an electronic database for storing and retrieving screening information about the inclusion and/or exclusion of these Yucca Mountain FEPs in TSPA-SR. The FEPs approach to scenario development is not unique to the Yucca Mountain Project (YMP). General systematic approaches are summarized in NEA (1992). The application of the FEPs approach in several other international radioactive waste disposal programs is summarized in NEA ( 1999)