An Investigation of the Structural Integrity of a Reactor Pressure Vessel Using Three-Dimensional Computational Fluid Dynamics and Finite Element Method Based Probabilistic Pressurized Thermal Shock Analysis for Optimizing Maintenance Strategy
An Investigation of the Structural Integrity of a Reactor Pressure Vessel Using Three-Dimensional Computational Fluid Dynamics and Finite Element Method Based Probabilistic Pressurized Thermal Shock Analysis for Optimizing Maintenance Strategy
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使用三维计算流体动力学和基于概率加压热冲击分析的有限元方法研究反应堆压力容器的结构完整性，以优化维护策略
DOI：
10.1115/1.4040698
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发表时间：
2018
期刊：
影响因子：
--
通讯作者：
K. Morishita
中科院分区：
文献类型：
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作者：
Xiaoyong Ruan;Toshiki Nakasuji;K. Morishita
反应堆压力容器（RPV）的结构完整性对核电站的安全运行至关重要。当紧急堆芯冷却系统（ECCS）运行时，由于失水事故（LOCA），冷却水注入反应堆压力容器（RPV），发生加压热冲击（PTS）加载。在中子辐照下，PTS载荷可能导致反应堆压力容器断裂。因此，有必要对反应堆压力容器在PTS加载过程中的性能进行评估，以保证反应堆的安全运行。在本研究中，考虑了RPV维护的优化，其中两个不同的尝试，调查RPV的完整性在PTS加载采用确定性和概率的方法。对于确定性的完整性评估，三维计算流体动力学（3D-CFD）和有限元法（FEM）模拟进行，并获得应力强度因子（SIF）作为裂纹位置的函数在RPV。另一方面，在概率完整性评估方面，计算了一个更实用的RPV上应力强度因子的空间分布。通过比较由此获得的分布与作为主曲线的一部分包括的断裂韧性，获得条件失效概率对RPV内的位置的依赖性。最后利用反应堆压力容器条件失效概率的空间分布，讨论了检查和维护的优先级。
The structural integrity of a reactor pressure vessel (RPV) is important for the safety of a nuclear power plant. When the emergency core cooling system (ECCS) is operated and the coolant water is injected into the RPV due to a loss-of-coolant accident (LOCA), the pressurized thermal shock (PTS) loading takes place. With the neutron irradiation, PTS loading may lead an RPV to fracture. Therefore, it is necessary to evaluate the performance of RPV during PTS loading to keep the reactor safety. In the present study, optimization of RPV maintenance is considered, where two different attempts are made to investigate the RPV integrity during PTS loading by employing the deterministic and probabilistic methodologies. For the deterministic integrity evaluation, three-dimensional computational fluid dynamics (3D-CFD) and finite element method (FEM) simulations are performed, and stress intensity factors (SIFs) are obtained as a function of crack position inside the RPV. As to the probabilistic integrity evaluation, on the other hand, a practically more useful spatial distribution of SIF on the RPV is calculated. By comparing the distribution thus obtained with the fracture toughness included as a part of the master curve, the dependence of conditional failure probabilities on the position inside the RPV is obtained. Using the spatial distribution of conditional failure probabilities in RPV, the priority of the inspection and maintenance is finally discussed.