压水堆核电机组反应堆首次临界启动研究  

Study on Initial Critical Start-up of Pressurized Water Reactor Nuclear Power Unit

作　　者：郑军伟 程雄伟 刘航 任意 ZHENG Junwei;CHENG Xiongwei;LIU Hang;REN Yi(China Nuclear Power Engineering Co.,Ltd.,Shenzhen 518124,China)

机构地区：[1]中广核工程有限公司,广东深圳518124

出　　处：《自动化仪表》2021年第S01期266-269,共4页Process Automation Instrumentation

摘　　要：为了使某压水堆核电机组的反应堆安全地达到首次临界状态,对反应堆临界过程的主要安全监督内容进行了研究,给出了使用相似三角形法外推临界点的步骤。为了保证外推计算的准确性,根据缓发中子半衰期和临界启动经验,提出了改变控制棒位置与记录中子计数率之间的时间间隔应不小于99 s的建议。对判断临界点和多普勒发热点的方法进行了研究,给出根据中子计数率倍增周期判断临界点的方法,以及根据反应堆冷却剂平均温度变化趋势判断多普勒发热点的方法。该机组采用了稀释反应堆冷却剂中的硼浓度使反应堆逼近临界,然后提升温度控制棒在堆芯的位置使反应堆临界的方法。通过执行临界启动试验,获得了反应堆的临界数据和多普勒发热点测量结果。根据多普勒发热点测量结果,计算出了零功率物理试验对应的核功率上限。根据临界过程和临界数据得出了反应堆首次临界启动合格的结论。研究结果可为压水堆核电机组首次临界启动提供参考。In order to make the reactor of a pressurized water reactor nuclear power unit reached the initial criticality state safely,the main safety supervision content of reactor criticality process is studied,and the steps for extrapolating criticality point by the similar triangle method are given.In order to ensure the accuracy of the extrapolation calculation,a suggestion is put forward in this study that the time interval between change control rod position and record neutron count rate should not less than 99 s based on the half-life period of delayed neutron and criticality start-up experience.The criticality point judgment method and the doppler heating starting point judgment method are studied,the method of judging the criticality point according to the neutron counting rate multiplication period and the method for judging the doppler heating starting point based on the change trend of the average temperature of the reactor coolant are given.The initial criticality start-up of the reactor adopts a method of diluting the boron concentration in the reactor coolant to make the reactor approach criticality,and then raises the position of the temperature control rod in the core to make the reactor criticality.The criticality data and doppler heating point measurement result of the reactor are obtained by carrying out the criticality start-up test,the upper limit of nuclear power corresponding to zero-power physics test is calculated according to the doppler heating point measurement result.According to the criticality process and criticality data,a conclusion that the initial criticality start-up of the reactor is qualified.The study results can be used as a reference for the first criticality start-up of reactor in pressurized water reactor nuclear power unit.

关 键 词：反应堆 核仪表 临界 中子计数率 多普勒发热点 物理试验 硼浓度 控制棒 

分 类 号：TH-89[机械工程]