An Extended Application Research of RELAP5 to Typical Non-LOCA of Passive NPP

As to passive nuclear power plant (NPP) transient/accident analysis, conservative codes rather than best estimated code such as RELAP5 are mainly used to do the non-LOCA analysis work. While considering the severer accident consequence, RELAP5 is selected in some cases as a tool for LOCA analysis so that safety margin can be gained and meanwhile, the safety NPP condition is guaranteed. In order to extend the RELAP5 application rang to passive NPP, a simulation capability research of RELAP5 to typical non-LOCA consisting of condition II, III and IV transient analysis of CAP1000 was conducted, and the results were compared with that analyzed by safety analysis code. Meanwhile, as to simulation skill, an innovative RELAP5 model was developed. In despite of different conservative degree of the key parameters, the response of the key equipment together with the variation tendency of the key parameters were consistent with that predicted by safety analysis code. Besides, the results met the acceptance criteria. It was showed that RELAP5 has the capability to simulate the CAP1000 non-LOCA.