反应堆冷却剂泵（RCP）是核电站（NPP）中反应堆冷却剂系统（RCS）的关键部件。 RCP的功能是驱动主回路中的反应堆冷却剂流量，并提供反应堆RCS主压力边界的完整性。 轴封系统由三个密封件组成，以控制反应堆冷却剂和安全壳之间的泄漏和压降。 对于具有静液压型的轴密封系统，除了密封支撑功能外，还包括第一密封件的插入部分作为保压边界的一部分。 对第一个密封插入件进行了修改，以提供用于被非能动关闭密封（PSDS）安装的空间。分析了改进的插入件模型的RCP保压边界由这些集成组件组成，包括密封件外壳，扩压器法兰，电机支撑架，壳体，热障法兰，主法兰和一些螺栓连接。 这些部件设计成与泵轴周向对称。 利用ANSYS Mechanical软件，在设计条件下根据RCC-M代码进行了二维轴对称应力分析。 将六种不同情况下的热负荷和机械负荷组合施加到模型上。 为了执行线性化的应力强度，在这些法兰和螺栓中分别生成了总共99个和18个线段。容许应力强度Sm用作极限值，以根据RCC-M标准验证分析结果。根据分析结果，壳体，扩散器法兰和隔热法兰中的应力强度都超过了这三个组件的Sm 值。 这些高应力受到施加到这三个组件表面的热负荷的深刻影响，这些负荷来自高温反应堆冷却剂。 除了这三个部分，在案例2中，在No1密封外壳插入件中出现了最高的一次膜应力强度，为167.17 MPa。对于螺栓，在案例中，在套管螺柱中也出现了最高的平均应力强度，同样是情况2， 的压力为223.74 MPa。插入件的修改减少了模型中发生的变形（变形），特别是在No1密封外壳插入件中。 与初始设计相比，No1密封壳体插件的最大变形从0.14125毫米减小到0.11991毫米（OBE朝上），从0.11577毫米减小到0.11105 mm（OBE朝下）。 因此，由于建立了较小的挠度，因此可以得出结论，在改进的嵌件中发生的变形不会对机械密封件的操作产生重大影响。此外，这项工作提供的分析结果证明并验证了带有改进型插入件的RCP保压边界满足RCC-M标准对1级保压组件的适用要求，但机壳，扩散器法兰和 隔热法兰。
Reactor Coolant Pump (RCP) is the key component of the Reactor Coolant System (RCS) in a Nuclear Power Plant (NPP). The function of the RCP is to drive the reactor coolant flow in the primary loop and provide the integrity of the primary pressure boundary of the RCS system. The shaft seal system is made up of three seals to control the leakage and pressure drop between the reactor coolant and the containment. For the shaft sealing system with hydrostatic type, the insert of the first seal is included as a part of the pressure-retaining boundary except for the sealing support function. The modification of the first seal insert (No1 seal housing insert) has been done to give a space for the Passive Shutdown Seal (PSDS) installation. The RCP pressure-retaining boundary with the modified insert model analyzed consists of such integrated components, including the seals housing, diffuser flange, motor support stand, casing, thermal barrier flange, main flange, and boltings. Those components are designed circumferentially axisymmetric to the pump shaft. The 2D-axisymmetric stress and thermal analysis are done under Design Conditions, utilizing ANSYS Mechanical software. The analysis aimed at verifying the safety aspect of the RCP pressure-retaining boundary with the modified insert based on the RCC-M Code standard, also to understand the impact of the modified insert deflection to the mechanical seals’ operation. The Combinations of the thermal and mechanical loads in six different cases are imposed on the model. A total of 99 and 18 line segments are generated in those flanges and boltings, respectively, in order to perform the linearized stress intensity. The Allowable stress intensity Sm is used as the limit value to verify the analysis results.Based on the analysis results, a high-stress intensity is happening in the casing, diffuser flange, and thermal barrier flange, which are exceeding the Sm values of those three components. These high stresses are profoundly affected by the thermal loads applied to those three components' surfaces, which come from a high-temperature reactor coolant. Excepting those three components, the highest primary membrane stress intensity of 167.17 MPa is founded happening in the No1 seal housing insert, in case 2. While for boltings, the highest average stress intensity is founded happening in the casing stud, also in case 2, with a magnitude of 223.74 MPa. Insert modification decreases the deformation that occurs in the model, particularly in the No1 seal housing insert. Compared to the initial design (unmodified insert), the maximum deformation of the No1 seal housing insert is decreasing from 0.14125 mm to 0.11991 mm (OBE directed upwards) and from 0.11577 mm to 0.11105 mm (OBE directed downwards). Hence, since the decreasing deflection is founded, it can be concluded that the deformation happening in the modified insert does not give a massive impact on the mechanical seals' operation. Moreover, the analysis results provided in this work prove and verify that the RCP pressure-retaining boundary with modified insert satisfies the applicable requirement provided by the RCC-M Code standard for the Class 1 pressure-retaining components, except for the casing, diffuser flange, and thermal barrier flange.
