核电厂堆芯冷却恶化恢复安注措施研究

The Safety Injection Recovery Strategy Research for NPP Under Inadequate Core Cooling

本文使用RELAPSCDAPSIM3.4程序建立核电厂事故分析模型,选取了典型的中、小冷段破口事故作为分析序列,针对堆芯冷却恶化现象采取恢复安注措施进行了详细的热工水力计算。着重分析了在辅助给水有效情况下,重启安注的时间窗口、启动上充应对安注失效情况下的有效性、有无安注箱注入敏感性等。分析结果表明:当堆芯出口温度超过923K(即650℃),恢复安注建立应急堆芯冷却流量措施对于中、小破口是有效的;启动上充对较小破口效果明显;安注箱有效注入对中破口冷却恶化事故缓解有重要作用。

The Paper applied RELAPSCDAPSIM3.4 program to establish the accident analysis model of NPP. The model selects the typical medium,small cold break accident sequence, to do the supportive Thermal-Hydraulics calculation for inadequate core cooling response with the safety injection recovery strategy. This paper emphatically analyzes the time window of Safety injection reinitiation, the effectiveness of adopting activating charging strategy for failure of SI, the sensitivity with or without accumulator injection with an effective auxiliary feed-water. The analysis indicates that. when the temperature of core exit is greater than 923 K, the strategy of recovering SI for medium, small cold break is effective; activating charging is beneficial evidently for the small break accident ; the accumulator injection plays an important role to relieve the influence of the medium break accidents under inadequate core cooling.