Safety analysis code SCTRAN development for SCWR and its application to CGNPC SCWR

Design analysis is one of the main difficulties during the research and design of SCWRs. Currently, the development of safety analysis code for SCWR is still in its infancy all around the world, and very few computer codes could carry out the trans-critical calculations where significant changes in water properties would take place. In this paper, a safety analysis code SCTRAN for SCWRs has been developed based on code RETRAN-02, the best estimate code used for safety analysis of light water reactors. The ability of SCTRAN code to simulate transients where both supercritical and subcritical regimes are encountered has been verified by comparing with APROS and RELAP5-3D codes. Furthermore, the LOFA and LOCA transients for the CGNPC SCWR design were analyzed with SCTRAN code. The characteristics and performance of the passive safety systems applied to CGNPC SCWR were evaluated. The results show that: (1) The SCTRAN computer code developed in this study is capable to perform design analysis for SCWRs; (2) During LOFA and LOCA accidents in a CGNPC SCWR, the passive safety systems would significantly mitigate the consequences of these transients and enhance the inherent safety.

► A new safety analysis code named SCTRAN is developed for SCWRs.
► Capability of SCTRAN is verified by comparing with code APROS and RELAP5-3D.
► A new passive safety system is proposed for CGNPC SCWR and analyzed with SCTRAN.
► CGNPC SCWR is able to cope with two critical accidents for SCWRs, LOFA and LOCA.