Recently, the media reproduced and reported on the two operating incidents that occurred on the Haiyang Nuclear Power Plant Unit 2 on March 6 announced on the National Nuclear Safety Administration website.The relevant responsible comrades of the National Nuclear Safety Administration made a further introduction today.
Haiyang Nuclear Power Plant Unit 2
The responsible comrade said that the National Nuclear Safety Administration's disclosure of information on the operation of nuclear power plants through the National Nuclear Safety Administration's website was conducted in accordance with the "People's Republic of China Nuclear Safety Law" and other relevant government information disclosure regulations, starting from June 2019. So far, 19 operating incidents in nuclear power plants have been disclosed, including 14 in 2019 and 5 in 2020.
On March 6, 2020, Unit 2 of Haiyang Nuclear Power Plant was in full power operation.
At 16:06, the controller of the reactor coolant pump 1A inverter control unit failed, causing the reactor coolant pump 1A to trip. The reactor was automatically shut down according to the design. The operator implemented the response procedures to stabilize the unit on the normal operating pressure / temperature platform.
At 20:39, after identifying the cause of the main pump 1A trip, the operating value will be executed according to the operating procedures, and all three main pumps will be restarted after being shut down. Before stopping the main pump, you need to isolate the non-borated water source according to the procedures. When the operating personnel at the scene closed the desalinated water pneumatic isolation valve, the operating device was close together, and the passive containment cooling water storage tank outlet was opened by pneumatic isolation, which caused the passive containment cooling system A channel to be put into operation.
After the incident, Haiyang Nuclear Power Plant defined the two incidents as operational events in accordance with Article 4.1.4 of the "Reporting System for Nuclear Power Plant Operating Units" which led to automatic or manual triggering of special safety facilities and reactor protection systems, and A notification of the operational incident was submitted to the National Nuclear Safety Administration.
During the two incidents, the crew had no radiological consequences, no personnel exposure, and no environmental pollution. According to the International Manual for the Classification of Nuclear and Radiation Incidents, both incidents are defined as Class 0 incidents, which are "non-safety-critical" incidents.
It needs to be further explained that the establishment of a nuclear power plant operating event reporting system and disclosure of operating events is a common practice in developing nuclear power countries around the world. The main purpose is to provide feedback on operating experience and maintain transparency of nuclear power information. Within a month after the occurrence of the operation event, the nuclear power plant shall also provide a detailed operation event report in accordance with the requirements of the operation event reporting system. In detailed operational incident reports, nuclear power plants need to provide in-depth investigation results of incidents and conduct root cause analysis to determine problems in equipment maintenance, operating procedures, personnel skills, and nuclear power plant management during the occurrence of operational incidents. And determine corrective actions based on existing problems. The National Nuclear Safety Administration will organize a review of nuclear power plant operation incident reports to confirm the appropriateness of nuclear power plant incident investigations, root cause analysis, and corrective actions taken.
In recent years, in order to further improve the effectiveness of operational experience feedback, the National Nuclear Safety Administration also selects several representative operational events each year and organizes independent evaluation activities. The National Nuclear Safety Administration also adopted multiple experience feedback channels to feed back relevant information on operating events to other nuclear power plants and relevant units, so that other nuclear power plants and units can also learn lessons from them. From the overall trend of China ’s nuclear power plant operating events, the average number of operating events has continued to decrease. The average number of operating events per unit in 2017, 2018, and 2019 was 0.87, 0.89, and 0.64, respectively, lower than those in the United States, 2.6, Since 2.1 and 1.7, it is also lower than many countries such as France, indicating that the level of operation and management of nuclear power plants in our country has continued to improve.
The responsible comrade emphasized that the National Nuclear Safety Administration will, as always, attach great importance to and continuously strengthen the supervision of the safety of nuclear facilities, strive to achieve the goal of modernizing the nuclear safety regulatory system and regulatory capabilities, and continue to improve the safety level of nuclear power in China.