核电厂松脱事件报警及应急响应研究

通过对松脱部件事件报警逻辑及国内外松脱部件监测法规和标准中关于松脱事件报警及应急响应的研究，结合国内某核电厂热试期间发生的松脱事件报警及报警事后应急响应，详细分析了该核电厂松脱事件过程。松脱事件报警分为绝对阈值和相对阈值报警，本文提出在系统报警逻辑中增加了计数因子和通道复核来提高报警准确率；GB/T 11807、IEC 60988和ASME均要求事件报警后采取措施确定报警是否是松脱部件所致，以及松脱部件对反应堆一回路系统产生的潜在危害进行评估；RG 1.133则要求确认松脱事件报警后应上报核管理委员会，GB/T 11807和IEC 60988则根据具体运行电厂确定，对于是否上报未做明确规定。基于国内某核电厂出现松脱事件报警及其应急响应，建议建立适合于国内核电厂松脱事件报警及应急响应机制，对于运行中出现的松脱事件及时确认，并对设备部件可能造成的损失情况进行及时评估，并对是否上报及采取何种措施做出进一步的规定。 

Research on Event?Alarm?and?Emergency Response of Loose Parts for Nuclear Power Plants

Based on the researches?of?the event alarm logic of loose parts and worldwide regulations and standards of loose parts event alarm and emergency response, combined with the loose parts event alarm and emergency response in?a domestic nuclear power plant during hot state function test, the process of?a ?loose part?event in that?nuclear power plant?is analyzed in detail. The loose parts event alarm is divided into absolute and relative threshold alarms.?To improve the alarm accuracy, counting factor and channel rechecking are increased in the alarm logic. GB/T 11807, IEC 60988 and ASME require to take measures to determine if the event alarm is caused by the loose parts,?and?the potential damage to the primary loop system of the reactor is evaluated by the loosen parts. RG 1.133?requires that the loose event alarm should be reported to the Nuclear Regulatory Commission. GB/T 11807 and IEC 60988?have no clear specification on?whether the loose part events?should be reported to the national nuclear safety administration, which?is determined according to the specific operation of the nuclear power plant.?Based on the alarm and emergency response?to?a loose?part?event?in a?nuclear power plant?in China, it is suggested that the?emergency response mechanism suitable for nuclear power plants?in China?should be established,?loose parts?events?should be determined in?time, and the possible loss of equipment components should be evaluated timely, and further provisions should be made on whether to report and take what measures.