压水堆核电厂燃料棒破损诊断分析研究  

Research on diagnosis of fuel defects in operating pressurized water reactors

作　　者：付鹏涛 章安龙 辜培勇 Fu Pengtao;Zhang Anlong;Gu Peiyong(China Nuclear Power Technology Research Institute,Shenzhen 518028,China;Daya Bay Nuclear Power Operation Management Co.,Ltd.,Shenzhen 518124,China)

机构地区：[1]中广核研究院有限公司,广东深圳518028 [2]大亚湾核电运营管理有限责任公司,广东深圳518124

出　　处：《强激光与粒子束》2024年第3期158-165,共8页High Power Laser and Particle Beams

基　　金：中国广核集团燃料战略专项(3100121513);中广核研究院有限公司青峰计划。

摘　　要：燃料棒是核电厂包容放射性物质的第一道屏障。燃料棒破损会导致冷却剂裂变产物活度升高,严重时机组须在数小时内后撤到停堆。通过取样监测的冷却剂放射化学数据可以一定程度上反映堆芯内装载燃料棒的破损情况。本研究介绍了压水堆核电厂功率运行期间冷却剂内裂变产物的来源,分析了裂变产物通过反冲和扩散方式的产生机理,通过求解迁移方程得到稳态情况下裂变产物活度的解析解。基于最小二乘法对反冲释放和扩散释放的裂变产物释放产生比进行解谱,建立了诊断压水堆燃料棒破损时间、破口程度、锕系核素泄漏、燃耗和燃料批次的定量分析模型。采用某百万千瓦压水堆运行中发生二次氢化的燃料循环的冷却剂裂变产物监测数据进行了验证,理论模型的分析结果也与机组停堆后啜漏检查和热室检查结果相符。Fuel cladding is the first barrier to confine the radionuclides produced in the reactor core.Once the fuel rods defect,fission product activity in the primary loops will increase and may lead to temporary shutdown of the reactor when fuel rod failure has deteriorated to certain levels.This paper introduces the theoretical mechanism of production and migration of fission product from defective fuel rods to the primary loops in the operating pressurized water reactors.The analytical solution of fission product concentration in primary loops is got based on the first-order differential equations for steady operation.Based on the release-to-birth ratios for recoil and diffusion by least squares method,a method is developed to diagnose the status of fuel failure in pressurized water reactors,including fuel failure time,the degrees of defect size,the disseminated actinides,the average burnup and the fuel batch.The prediction results of fuel failure are verified well with that of a typical fuel failure with secondary degradation in one commercial pressurized water reactor,as well as those of the sipping test and the post irradiation examination.

关 键 词：燃料破损 裂变产物 释放产生比 二次氢化 

分 类 号：TL751[核科学技术—辐射防护及环境保护]