失去交流电源事故下AP1000堆芯节块模型敏感性分析

本文以失去交流电源事故作为计算条件,对AP1000核电厂堆芯节块模型的敏感性进行了研究.利用现有AP1000核电厂的资料建立了堆芯节块划分模型并修改了堆芯节块划分,经计算并与安全分析报告进行对比,验证了推芯节块划分模型的正确性.在获得验证的模型的基础上,通过修改堆芯节块划分,进行了模型敏感性分析.分析结果表明：堆芯节块数目的变化对事故计算的结果有较大影响,随着堆芯节块数目的减少,核电厂反应堆冷却剂系统（Reactor Cooling System,以下简称RCS）系统压力的下降速度降低;温度升高;堆芯补水箱（Core Makeup Tank,以下简称CMT）系统投入时间延迟非能动余热排出系统（Passive Residual Heat Removal,以下简称PRHR）提前工作;CMT和PRHR的最大流量显著增加.

Analysis on AP1000 Core Nodal Model Sensitivity in the Case of the Accident of Lossing AC Power

In this paper, based on the calculation in case of the accident of lossing AC power, the sensitivity of AP1000 nuclear power plant relap model was studied. Using existing data of AP1000 nuclear power plant a reactor core nodal division model and nodal division were established. After calculating and comparing with the safety analysis report, the correctness of the model was verified. In the model on the basis of a proven model, by modifying the core section of the block division, a sensitivity analysis of the model was conducted. The results showed that： the number of core nodal division has a greater influence on the calculation result. With reduction of the core nodal division number, lower pressure drop speed of the primary circuit system, the temperature rising, CMT operating delayed, PRHR working ahead and significant increase of CMT and PRHR flow were observed.