AP1000反应堆冷却剂泵“3 s供电”问题分析

Analysis of the “3 seconds power”of AP1000 reactor coolant pump

针对AP1000核电技术中反应堆冷却剂泵因所采用的屏蔽泵转动惯量小、泵的惰走时间短,在汽轮机跳机后,如何保持反应堆冷却剂泵电机3 s供电时间的问题,结合AP1000核电厂系统固有特点,分析了"孤岛运行"、"机组满功率运行"、"机组满功率运行+500 kV外电网失去"、"机组满功率运行+外电网失去"4种极限工况特点。根据电网稳定性和堆芯偏离核态沸腾仿真结果,分析了汽轮机跳机后的电气系统响应和反应堆冷却剂系统响应。研究结果表明,在汽轮机跳机后系统能满足反应堆冷却剂泵3 s供电时间要求,以增加冷却剂强迫循环时间,实现安全停堆。

Aiming at how to retain 3 seconds power for the reactor coolant pump motor after the shutdown of steam turbine, because of canned-motor pump being applicated as the reactor coolant pump in AP1000 nuclear power, with small inertia and short running down time, the characteristics were analyzed under extreme conditions, such as ＂island operation＂, ＂ full power operation＂, ＂full power operation ＋ 500 kV power lose＂, ＂full power operation and external power lose＂, combined with the inherent characteristics of AP1000 nuclear power plant. The electrical system response and the reactor coolant system response were analyzed according to the simulation results of the power- grid stability and the reactor core DNBR. The research results indicate that the ＂3 seconds power＂ of reactor coolant pump after the shutdown of steam turbine can be satisfied to increase the forced circulation time of coolant and shut down safely.