AP1000核电厂RELAP5 SB-LOCA分析模式建立与应用

Establishing and Application of AP1000 Nuclear Power Plant RELAP5-Code SB-LOCA Model

建立了AP1000核电厂RELAP5 SBLOCA分析模式,并与美国西屋公司NOTRUMP程序计算结果进行比对。进一步应用此分析模式对第三代核电技术AP1000在小破口失水事故下的设计特性、破口面积大小以及功率提升对小破口失水事故现象的影响进行了量化的分析研究。自动降压系统ADS失效量化分析结果显示,ADS失效时堆芯内的水在17 500s左右堆芯水位将无法有效覆盖燃料,说明自动降压系统对AP1000的反应堆冷却系统在小破口失水事故工况下的泄压是不可缺少的。分析结果进一步显示,在小破口失水事故下,破口面积越大,包壳峰值温度会越高,破口面积每增加0.012 26m2(5%管道面积),PCT温度上升约36K;提升功率也会使包壳峰值温度升高,分析结果显示每增加5%功率,小破口失水事故的PCT上升约42.26K。

An AP-1000 SBLOCA analytical model has been developed with RELAP5 code and it was applied to analyze special design features of AP1000 for SBLOCA event.Typical SBLOCA results calculated with RELAP5 were compared with the calculations from Westinghouse NOTRUMP code.Besides,the effect of break size,failure of ADS and power uprate on SBLOCA also have been analyzed.It was found that the severity of SBLOCA will increase with the break size,the failure of ADS will result in a late core uncovery by 17 500 seconds,and the PCT will increase with the power up-rate by 42 K for every 5% power increase.