Analysis of Steam-Line-Break Transient with RELAP5/MOD1.5 and Comparison to CESSAR (PWR)

摘要

Section 15.1.5 of the Standard Review Plant outlines the areas of review and the acceptance criteria for the analysis of steam system piping failures inside and outside of containment. Combustion Engineering (C-E) submitted analysis of the limiting steam line break (SLB) transient for the C-E 3800 MW nuclear steam supply system as Appendix 15C to the CESSAR FSAR. Conservative initial conditions and analysis assumptions were utilized in the transient calculation which was performed with the CESEC-III computer program. Argonne National Laboratory (ANL), under contract to the Nuclear Regulatory Commission, performed audit calculations of SLB transients presented in the CESSAR FSAR, with RELAP5/MOD1.5 (Cycle 26) and compared them with the CE results. The transient presented here is a large steam line break during full power operation with a concurrent loss of offsite power. The objective of this study was to examine the impact of mixing of cold primary fluid returning to the core from the affected steam generator with the hot fluid returning from the intact side, and its effect upon the potential return to power due to moderator feedback. (ERA citation 08:046304)