In fission reactors, neutron radiation is the main reason for the displacement of atoms in the crystalline lattice of the material. In this study, this damage is investigated on the fuel clad of the Bushehr reactor, which is Zr + 1%Nb. The MCNPX code is used to simulate the core of the reactor and find the highest neutron flux in the core of the reactor. Both the SRIM and SPECTER codes are used to study the neutron interaction with matter. The damage rate of the SRIM code is calculated in full cascade and quick damage modes, calculated as 2.05E−06 (dpa/s) and 1.06E−06 (dpa/s), respectively. Also, the damage rate in the SPECTER code is 1.0193E−06 (dpa/s), and the result has been compared with the SRIM code results. Using the calculated displacement per atom (dpa), the yield stress of the material, which is the resistance to the stresses, and the electrical resistivity of the material are calculated for 3 years of reactor operation. Both factors have increased over time, and the fuel clad lost its original function.

中文翻译：

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中子辐射对布什尔反应堆包壳屈服应力的影响

在裂变反应堆中，中子辐射是材料晶格中原子发生位移的主要原因。在本研究中，对布什尔反应堆的燃料包壳（Zr + 1%Nb）研究了这种损坏。MCNPX 代码用于模拟反应堆的堆芯并找到反应堆堆芯中的最高中子通量。SRIM 和 SPECTER 代码都用于研究中子与物质的相互作用。SRIM 代码的损坏率在全级联和快速损坏模式下计算，分别计算为 2.05E-06 (dpa/s) 和 1.06E-06 (dpa/s)。此外，SPECTER 代码中的损坏率为 1.0193E−06 (dpa/s)，该结果已与 SRIM 代码结果进行了比较。使用计算出的每原子位移 (dpa)，材料的屈服应力，即对应力的抵抗力，并计算了反应堆运行 3 年的材料电阻率。随着时间的推移，这两个因素都增加了，燃料包壳失去了原来的功能。