CPR1000核电厂全厂断电事故缓解措施有效性分析

Analysis on the Effectiveness of Mitigation Measures for the SBO Accident in CPR1000 NPP

为防止发生高压熔堆,降低安全壳内氢气燃爆的风险,CPR1000型核电厂采取了一系列的严重事故缓解措施。应用新版的MELCOR 2.1程序,针对有无严重事故缓解措施条件下全厂断电(SBO)事故序列进行计算分析,模拟了事故进程中堆芯的状态,对事故过程中氢气的产生、分布及其行为进行了评估。分析结果表明,稳压器卸压功能延伸能够有效防止高压熔堆现象的发生,消氢系统通过在安全壳内的合理布置,可有效降低氢气爆炸的风险,防止了安全壳发生早期失效。

To prevent high-pressure core melt accident and reduce the risk of hydrogen explosion in the containment,a series of severe accident mitigation measures were adopted by CPR1000 type nuclear power plant.MELCOR code was used to analyze the SBO accident under the condition with and without mitigation measures.The core status,hydrogen production,distribution and behavior in the containment were evaluated.The results show that the pressurizer pressure relief function extension can prevent high-pressure core melt accident,and the reasonable distribution of hydrogen recombiners can reduce the risk of hydrogen explosion.The mitigation measures can avoid the early failure of containment.