秦山核电厂堆内构件围板螺栓老化评估

Aging Evaluation of Baffle Bolts for Reactor Internals of Qinshan Nuclear Power Plant

介绍了秦山核电厂为评估堆内构件围板螺栓的实际老化状态,在吸收总结国际上堆内构件老化机理研究成果的基础上建立了堆内构件围板螺栓的老化机理判断准则,用其评估识别围板螺栓主要受磨损、应力松弛、辐照肿胀、辐照促进应力腐蚀开裂等老化机理的影响,并针对老化机理可能导致的缺陷类型,开发了水下超声检查技术补充常规的目视检查方法,从而制定评估老化状态的检查方案。评估结果表明,秦山核电厂堆内构件围板螺栓老化状态良好,尚未发生变形、裂纹等老化失效现象。实践证明该评估方法行之有效,可用于压水堆核电厂部件老化评估工作。

In order to evaluate the actual aging state of baffle bolts for reactor internals in Qinshan Nuclear Power Plant,on the basis of absorbing and summarizing the international research results on the aging mechanism of reactor internals,a criterion for judging the aging mechanism of reactor internals is established,and is used to evaluate and identify the aging mechanism of baffle bolts mainly affected by wear,stress relaxation,irradiation swelling,irradiation-promoted stress corrosion cracking and so on.Besides,according to the possible defect types caused by the aging mechanism,the underwater ultrasonic inspection technology is developed to supplement the conventional visual inspection method,so as to formulate the inspection scheme to evaluate the aging state.The evaluation results show that the baffle bolts for reactor internals in Qinshan Nuclear Power Plant are in good aging condition,and no deformation,crack and other aging failure phenomena have occurred.Practice has proved that the evaluation method is effective and can be used for the aging evaluation of PWR nuclear power plant components.