Quantitative techniques for nuclear plant safety assessment and design

The increasing possibility for using quantitative risk and reliability criteria in the siting and licensing of nuclear plant raises various problems for those who must decide if and how such requirements will be incorporated into the regulatory review framework. The analysis of a system which raises important issues and problems related to the use of quantitative risk and reliability methods and requirements in the design assessment process is discussed. In particular, the development of a fast fault tree method useful for the evaluation of large trees is discussed and the comparative performance of the method with well-known codes presented. It is suggested that the method may lend itself to further improvement in terms of computing efficiency and a role for an ultra fast fault tree resolution method capable of dealing with large fault trees is discussed. (author)