压水堆核电厂堆外源量程探测器计数率分析

Analysis of Ex-core Source Range Detector Count Rate in PWR Nuclear Power Plant

压水堆核电厂启动过程中,次级中子源为堆外源量程探测器提供本底计数率,避免测量盲区,确保反应堆安全启动。但次级中子源的引入会为核电厂带来较大的经济和环境负担,同时也需承受次级中子源破损等带来的风险。为此,可使用受辐照燃料组件的自发裂变中子源进行替代,即无源启动方式。通过研究堆外源量程探测器计数率的理论计算方法,并基于运行电厂测量数据进行分析验证,为源量程探测器计数率的理论预估提供了较为完善的理论方法流程。本文结果可为无源启动源量程探测器计数率分析提供支持,同时也可用于次级中子源装载量或布置位置的优化分析等。

During the startup of pressurized water reactor(PWR)nuclear power plant,the secondary neutron source provides background count rate for the ex-core source range detectors,avoiding measurement blind zone and assuring the reactor’s safety.However,the usage of the secondary neutron source will bring biggish economic and environmental burdens and increase the plant operation risk from the secondary neutron source damage.So,the spontaneous fission neutron from irradiated fuel assembly can be used instead,which is called startup without neutron source.In this paper,the calculation method of detector count rate was studied and verified based on the measured data from the operation plant,and it provides a relatively perfect theoretical and methodological process for the theoretical prediction of the count rate of the source range detector.This method can provide theoretical support and reference for detector count rate analysis in demonstration of startup without neutron source,and optimization analysis of secondary neutron source loadage and disposal.