The Screening Methodologies and/or Achievement Evaluation in Japanese FR Cycle Development Program With the Changing Needs for Evaluation

This paper argues the characteristics evaluation of Fast Reactor and fuel cycle concepts in the FS “Feasibility Study on commercialized fast reactor cycle systems” and the achievement of the performance evaluation conducted in FaCT (Fast Reactor Cycle System Technology Development) project in Japan. At the beginning of FS phase-I (JFY1999), a combinatorial number of candidate concepts with innovative technologies were screened. After the FS phase-I evaluation, the several promising FR cycle concepts were selected to achieve consistency between FR system and fuel cycle system. Analytical evaluation methodologies were developed to compare candidate FR cycle concepts in the FS phase-II (JFY2001 to JFY2005). Finally, the main concepts were decided mainly based on the technical summary (a kind of qualitative evaluation) of FR cycle concepts besides quantitative evaluation in FS phase-II. Sodium cooled FR combined with simplified pelletizing fuel fabrication, and advanced aqueous reprocessing was selected as “main concept” after Japanese government review. In the FaCT phase-I (JFY2006 to JFY2010), the achievement toward the performance criteria / design requirements for the conceptual design of the commercialized facility developed in the FaCT phase-I was also evaluated. However, the objectives of the evaluation were to confirm the direction and the problems of R&D plans, development targets and design requirements. No aggregation methodologies were used in the FaCT final evaluation. Since the design requirements were set as challenges to achieve higher performance, although some items of respective facilities showed an insufficient achievement, a comprehensive evaluation determined that the performance criteria set by the JAEC were achieved in general. The appropriate methodologies to evaluate the total FR and related fuel cycle system varies at different periods, according to our experience in Japanese FR cycle development program. This paper argues the way of methodologies with the changing needs and objectives of evaluation.