核电厂二级PSA释放类划分及代表性事故序列选取研究

Study on Level 2 PSA Release Categories and Selection of Representative Accident Sequence in Nuclear Power Plants

国内AP1000、EPR、华龙一号等核电工程项目已将二级概率安全分析(PSA)源项用于应急输入,但二级PSA释放类的划分以及各释放类代表性事故序列的选取尚无明确可操作的方法,需要进一步开展研究。对比研究国内先进核电厂二级PSA释放类划分和代表性事故序列选取情况,以国内某三代先进压水堆核电厂为例,在同一释放类中根据频率和后果选取4个不同的严重事故序列开展源项计算。结果表明,同一释放类4个不同事故序列的源项结果差别较大,建议释放类划分以应用为导向,根据分析目的进行迭代,对同一释放类应选取多个事故序列进行对比分析,以论证释放类划分的合理性和事故序列的代表性。

Domestic nuclear power projects such as AP1000, EPR and HPR1000 have used the level 2 PSA source terms for the emergency input, but there is no clear operational methods for the division of level 2 PSA release categories and the selection of representative accident sequences for each release category, and further research is required. Comparing the level 2 PSA release categories and the selection of representative accident sequences for each release category of domestic advanced nuclear power plants, taking a domestic generation Ⅲ advanced pressurized water reactor nuclear power plant as an example, the source terms were calculated for 4 different accident sequences that selected from a release category based on frequency and consequences. The results show that the source results of different accident sequences are quite different. It is recommended that the release category be divided into application-oriented and iterative according to the analysis purpose, and multiple accident sequences should be selected for the same release category for comparative analysis to demonstrate reasonable release categories and representativeness of accident sequences.