大型压水堆核电站换料机的强度分析

Strength analysis of refueling machine for large PWR in nuclear power plant

压水堆核电站换料机对保障核电站安全运行具有重要的作用,对其主要结构的动力计算和强度评定具有重要的意义。本文应用有限元分析软件ANSYS 12对1 000 MW核电站大型换料机进行了有限元建模,并分别在正常工况(启动、制动)、异常工况(OBE)和事故工况(SSE)下进行了动力计算;采用SRSS方法对3个不同方向地震反应谱下的结构响应(内力、应力)进行了工况组合,并进一步考虑了自重条件的不利影响。根据RCCM规范对换料机主要结构、螺栓、焊缝的强度和辅吊支腿的稳定性进行了评定,并在此基础上对抓取燃料组件的指形钩进行了局部强度分析。评定结果表明换料机的强度在不同工况下均满足规范要求。

The refueling machine of PWR plays important roles in nuclear power plant operation,and the dynamic analysis and strength assessment should be carried out to check its safety.In this paper,the finite element model（FEM） was established with the software ANSYS 12 for the refueling machine structure of large 1 000 MW PWR.The dynamic computations were performed under three work conditions,i.e.normal（cart starting and braking）,abnormal（OBE） and accident（SSE） conditions,respectively.The structure responses（internal force and stress） of refueling machine under earthquake response spectrum in three directions were combined with the method of square root of square sum（SRSS）.Moreover,the static response under gravity was also considered to construct the most critical conditions.With the simulated results,the strength of main structure,bold and weld joint,and the stability of landing leg for additional crane were assessed based on the RCCM code.At last,the local stress analysis of finger-form hook,which function is to take fuel assemblies,was also analyzed,while its strength was also assessed.The results show that the strengths of the refueling machine under various working conditions can meet the safety requirements.