辐照对银铟镉控制棒价值的影响分析

为分析银铟镉（Ag-In-Cd）控制棒内各核素经反应堆中子辐照后的消耗情况以及核素消耗对控制棒价值的影响，本研究采用蒙特卡罗程序模拟了Ag-In-Cd控制棒内主要核素在反应堆运行期间的燃耗，并结合控制棒宏观中子吸收截面和控制棒内的中子注量率水平变化，分析了辐照前后控制棒价值的变化。研究结果表明，控制棒中113Cd随着辐照时间增加而加速消耗，107Ag、109Ag和115In消耗速率相对较慢；控制棒总的宏观中子吸收截面在辐照后降低，但是107Ag、109Ag和115In的中子吸收截面明显地增加；辐照后控制棒内的中子注量率增大，控制棒总中子吸收率无明显变化，即控制棒价值无明显变化。 

Study on Irradiation Effect for Value of Ag-In-Cd Control Rods

In order to study the main neutron absorber nuclides of the Ag-In-Cd control rods in the reactor and its effect on the control rod value, Monte Carlo method is used to simulate the burnup of the main nuclides in Ag-In-Cd control rods during the reactor operation, and the neutron flux in the control rod and the macroscopic cross-section are analyzed, to investigate the value of the control rods before and after irradiation. The results show that the nuclide 113Cd in control rods decreases sharply with the increasing of the irradiation time, while 107Ag, 109Ag and 115In decrease slowly; the macroscopic cross-section of the control rods decreases, while the macroscopic cross-section of 107Ag, 109Ag and 115In increase; the neutron flux in the control rods increases, hence the neutron absorber rates in the Ag-In-Cd equal to that in the no-irradiation control rods.