论文部分内容阅读
最佳估算加不确定性(BEPU)事故分析方法同传统的保守性事故分析方法相比,可获取现实的分析结果和安全裕量,在保证核电厂安全性的前提下,提高核电厂的经济效益和运行灵活性。针对CNP600的设计特点,利用最佳估算程序RELAP5-3D建立热态满功率(HFP)和热态零功率(HZP)条件下的弹棒事故(REA)分析模型。通过弹棒事故现象识别分级表(PIRT)识别事故瞬态下重要的过程和现象,筛选出对关键安全参数有重要影响的输入参数。利用DAKOTA程序对重要不确定性输入参数进行拉丁超立方抽样(LHS),通过非参数统计方法计算关键安全参数的单侧容忍上限。计算结果显示:两种弹棒条件下,REA瞬态过程中的最大芯块平均焓值、芯块峰值温度、包壳峰值温度、系统峰值压力均满足弹棒事故验收准则;利用非参数统计方法计算的核功率峰值单侧容忍上限结果合理,最大芯块平均焓值单侧容忍上限计算值同传统弹棒事故保守计算值相比具有可观的安全裕量。
The best estimate plus uncertainty (BEPU) accident analysis method can obtain realistic analysis results and safety margin compared with the traditional conservative accident analysis method. Under the premise of ensuring the safety of the NPP, it can improve the economy of the NPP Benefits and operational flexibility. According to the design features of CNP600, the REA analysis model under hot HFP and HZP conditions is established by the best estimation program RELAP5-3D. PIRT identifies the important process and phenomena under accident transients and filters out the input parameters that have a significant impact on the key safety parameters. The Latin hypercube sampling (LHS) was performed on the input parameters of important uncertainties using the DAKOTA program, and the upper limit of unilateral tolerance of key safety parameters was calculated by non-parametric statistical method. The calculation results show that the average enthalpy of the largest pellet, the peak temperature of the pellet, the peak temperature of the cladding and the peak pressure of the system satisfy the acceptance criteria of the projectile during the transient state of the two types of projectile under the two kinds of projectile conditions. By using the nonparametric statistical method The calculated upper limit of unilateral upper limit of peak power of nuclear power is reasonable, and the calculated upper bound of unilateral tolerance of average enthalpy of core has considerable safety margin compared with the conservative calculation of traditional bullet accidents.