基于损伤力学的TMSR-LF1堆容器接管非弹性蠕变损伤分析

Inelastic creep damage analysis of RPV nozzle in TMSR-LF1 based on damage mechanics

钍基熔盐液态实验堆(Thorium Molten Salt Reactor-Liquid Fuel 1,TMSR-LF1)反应堆压力容器(简称"堆容器")长期在650°C的高温下服役,对其进行蠕变损伤分析至关重要。本文旨在采用非弹性分析方法进行TMSR-LF1堆容器接管的蠕变损伤计算与评估。基于损伤力学理论,通过拟合650°C下UNS N10003合金的蠕变试验数据,得到了Lemaitre多轴蠕变损伤模型的材料常数。蠕变断裂寿命的理论预测值与试验结果基本吻合,最大误差7.38%。然后通过有限元分析,得到了TMSR-LF1堆容器接管正常运行工况下的等效应力,并根据Lemaitre多轴蠕变损伤模型得到了非弹性蠕变损伤值。计算结果表明:TMSR-LF1堆容器接管在10年寿期内的最大蠕变损伤约0.082,满足限值要求。

[Background]The reactor pressure vessel(RPV)of thorium molten salt reactor-liquid fuel 1(TMSRLF1)has been designed to operate at 650°C for long-term period,therefore,it is extremely important to analyze its creep damage.[Purpose]This study aims to calculate and assess the creep damage of the RPV nozzle in TMSR-LF1 with an inelastic analysis method.[Methods]Based on damage mechanics theory,firstly,the material constants of Lemaitre multi-axial creep damage model are obtained by fitting the creep test data of UNS N10003 alloy at 650°C.Then the equivalent stress and creep damage of the RPV nozzle in TMSR-LF1 under normal operating conditions are calculated by finite element analysis.[Results]The theoretical prediction values of creep fracture life are basically consistent with the experimental results,with a maximum error of 7.38%.The calculation results indicate that the maximum creep damage of the RPV nozzle in TMSR-LF1 reaches 0.082,which meets the 10-year life limit requirement.[Conclusions]The analysis method and results have certain reference value for the structural integrity evaluation of elevated temperature equipment in TMSR.