超临界水冷堆与WWER1000型压水堆的安全特性比较分析

Comparative Safety Analysis between Supercritical Water Cooled Reactor and WWER-1000 Type PWR

超临界水冷堆(SCWR)是在高于水的临界点(374℃,22.1 MPa)的温度和压力下运行的反应堆。它的设计为一次通过循环,其中没有再循环回路。这点是与现在运行的轻水堆的最大不同。在超临界水堆电站系统中,以控制棒、汽轮机控制阀与反应堆冷却剂泵为主要的控制方式。通过对比分析超临界水冷堆与田湾核电站WWER1000型压水堆主泵卡轴事故下的安全特性,得出超临界水堆给水流量的丧失会造成反应堆冷却剂流量的丧失,而WWER1000型压水堆给水流量的丧失并不会造成反应堆冷却剂流量的丧失;WW-ER1000型压水堆的安全系统有控制棒、蒸汽发生器的主蒸汽旁排阀、应急给水泵,这些安全配置与超临界水冷堆相似;相比WWER1000型压水堆,超临界水冷堆在压力较快达到稳定状态前提下,其最高包壳温度有个剧烈变化过程,但超临界水冷堆和WWER1000型压水堆在卡轴事故发生后,都能建立稳定的自然循环。

The supercritical water cooled reactor （SCWR） is essentially light water reactor （LWR） operating at high pressure and temperature beyond the thermodynamic critical point of water （374 ℃ ,22.1 MPa）. It is a once-through direct cycle and the recirculation system is not necessary. This is the biggest difference between SCWR and LWR. The control rod, steam turbine control valves and reactor coolant pumps are mainly used as the power plant control system. Through the comparative analysis of safety characteristics during the primary pump seizure accident in SCWR and WWER-1000 type PWR,we will conclude that loss of coolant supply will lead to loss of reactor coolant flow in SCWR,but loss of coolant supply will not lead to loss of reactor coolant flow in WWER-1000 PWR ;the security con- figurations such as control rod, bypass valve of steam generators, the emergency feed-water pump are similar to that of SCWR ; compared with WWER-1000 type PWR, there is a radical change of the cladding temperature on the premise of the pressure achieving stable state rapidly,but both SCWR and WWER-1000 type PWR can build the stable natu- ral circulation during the primary coolant pump seizure accident.