三代压水堆核电厂DCH参数敏感性研究

Parametric Sensitivity Study of Direct Containment Heating for GenⅢPWR

安全壳直接加热(DCH)是导致安全壳早期超压的主要贡献之一,严重威胁安全壳完整性,并可能造成放射性物质早期大量不可控释放。本文以我国某三代压水堆为研究对象,首先基于风险导向的事故分析方法(ROAAM),利用双隔间平衡(TCE)模型编写程序计算典型事故工况下的DCH载荷;其次结合安全壳失效概率曲线得出DCH现象造成的安全壳失效概率;最后对计算程序中不易得到的参数或经验值等不确定性较大的参数进行敏感性分析,归纳敏感性分析结果,找出敏感参数的不确定因素。结果表明:熔融物质量、堆腔几何设计、安全壳布置设计会直接影响DCH后果。

Direct containment heating(DCH)is one of the major contributions to early overpressure of containment,which could threaten the containment integrity and lead to the early uncontrollable release of radioactive materials.In this study,one of the GenⅢPWR was selected as the research target.Firstly,a Fortran program with two-cell equilibrium(TCE)model and ROAAM was compiled to calculate DCH load for some typical sequences.Then,containment failure rate resulted from DCH was calculated for the typical sequences combined with containment failure probability curve.Finally,some parameters that are not easily to get in design phase or the reference research experience values were sorted out,the sensitivity analysis results were concluded,the uncertain factors of these parameter were found out.The study results reveal that the quality of melt core,geometric design of the reactor cavity,containment layout will affect the consequences of DCH directly.