Abstract Westinghouse type plants in the United States (US) and Europe have a manual trip procedure of the reactor coolant pumps (RCP) in the case of a small break Loss of Coolant Accident (LOCA) with the high pressure injection (HPI) system functioned. This is in response to the Three Mile Island (TMI) accident in order to maintain as much the forced core cooling as possible. On the other hand, the initial design of Japanese pressurized water reactor (PWR) plants were designed to shut off the non-safety power supply buses on receiving of safety injection (SI) actuation signals and to handle an accidents only with safety facilities. But other part of design of Japanese PWR plants had basically same as Westinghouse type plants in the US and Europe. Although it was modified to no shut off the non-safety power supply buses in all Japanese PWR plants after the Mihama Unit 2 steam generator tube rupture (SGTR) accident, but it was added an automatic RCP trip logic on receiving of SI actuation signals. Therefore Japanese PWR plants shutting off the forced core cooling using SI actuation signals. As the results, Japanese PWR plants have disadvantages such as increased risk of pressurized thermal shock (PTS) by rapid cooling of the reactor coolant system (RCS), reducing operational margin in transient events, and increase of radioactive release by SGTR.

中文翻译：

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在需要安全注入系统的事故中关闭强制堆芯冷却日本压水堆发电厂的风险

摘要 美国 (US) 和欧洲的 Westinghouse 型电厂在高压喷射 (HPI) 系统运行的情况下，在发生小故障冷却剂损失 (LOCA) 的情况下，具有反应堆冷却剂泵 (RCP) 的手动跳闸程序。 . 这是为了应对三英里岛 (TMI) 事故，以尽可能保持强制堆芯冷却。另一方面，日本压水堆（PWR）工厂的初始设计旨在在接收到安全注入（SI）启动信号时关闭非安全电源总线，并仅使用安全设施来处理事故。但日本压水堆设计的其他部分与美国和欧洲的西屋型电厂基本相同。虽然在美浜二号机组蒸汽发生器管破裂（SGTR）事故后修改为不关闭日本所有压水堆工厂的非安全电源总线，但它增加了接收SI驱动信号的自动RCP跳闸逻辑。因此，日本压水堆工厂使用 SI 驱动信号关闭强制堆芯冷却。因此，日本压水堆工厂存在一些缺点，例如反应堆冷却剂系统 (RCS) 的快速冷却会增加加压热冲击 (PTS) 的风险，降低瞬态事件中的运行裕度，以及 SGTR 会增加放射性释放。