Initial critical judgment method for reactor core of pressurized water reactor unit

The invention belongs to the technical field of nuclear power plant reactor physics, and particularly relates to a pressurized water reactor unit reactor core initial critical judgment method. And continuously monitoring the neutron counting rates of the four source range channels, and when the neutron counting rates of the four source range channels are consistent, enabling the reactor core to reach an initial critical state. And the four source range channels are respectively arranged in the radial directions of 0 degree, 90 degrees, 180 degrees and 270 degrees of the reactor core. The method can accurately determine the initial critical state of the reactor core, is stable and reliable in measurement result and simple, and can be popularized and used. 本发明属于核电厂反应堆物理技术领域，具体涉及一种压水堆机组堆芯初始临界判断方法。持续监测四个源量程通道的中子计数率，当四个源量程通道中子计数率一致时，堆芯达到初始临界状态。所述的四个源量程通道分别布置在堆芯径向0°、90°、180°、270°方向。利用该方法可以准确确定反应堆堆芯初始临界状态，该方法测量结果稳定可靠、方法简单，可以推广使用。