方家山核电厂动态通量测量技术的开发与应用

Development and Application of Dynamic Flux Map Measurement Technique of Fangjiashan

核电厂压水堆机组在换料大修后的各升功率平台需实施通量图测量试验,以验证堆芯核设计的准确性与安全性。由于受堆芯氙毒瞬态变化的影响,在达到各目标功率平台后,通常需要等待至少24 h使堆芯状态稳定后才能实施测量,耗费了大量的时间。针对传统测量方法的局限性,本研究成功研发了动态通量测量技术。应用该项技术实施试验时,在目标功率平台仅需等待6 h,并应用三维堆芯计算软件ORIENT系统结合实测试验,精确推演出堆芯在氙平衡后的功率分布。经过方家山机组多次现场验证试验,证明了动态通量测量技术的适用性及精准性。目前,方家山1、2号机组均已正式应用动态通量测量技术,缩短了机组低功率平台的停留时间,有效提升了电厂的经济效益。

In order to verify the accuracy and safety of the reactor core design of Pressurized Water Reactor(PWR)in Nuclear Power Plant,the flux map measurement test should be carried out for each power increase platform after refueling outage.Due to the influence of xenon transient changes in the core,after reaching the target power platform,it is usually necessary to wait at least 24 hours for the core to be stable before the measurement can be carried out,which consumes a lot of main line time.In view of the limitation of traditional measurement methods,the dynamic flux map measurement technique has been successfully developed by China Nuclear Power Operation Management Co.,Ltd and Shanghai Nustar Nuclear Power Technology Co.,Ltd When the test is carried out with this technique,it only takes 6 hours to wait at the target power platform,uses 3D core calculation software ORIENT system combined with the field test,and accurately estimate the power distribution under xenon equilibrium.The applicability and accuracy of the dynamic flux map measurement technique have been proved by many field tests in Fangjiashan units.At present,the dynamic flux measurement technique has been formally applied in Fangjiashan Unit 1&2 units,which reduces the waiting time of the low-power platform of the unit and effectively improves the economic benefits of the power plant.