Study on radiation degradation of nuclear power cable materials

Abstract

During the operation of nuclear power plants, it is necessary to monitor and evaluate the aging of cable materials. In this paper, we evaluate the irradiated use status of two types of cable insulation materials used in nuclear power plants-cross-linked polyethylene (XLPE) and ethylene propylene diene methylene (EPDM). Firstly, two kinds of cable materials are subjected to accelerated radiation aging with different cumulative doses, and the macro-mechanical properties and microstructure changes of the cable materials after different doses are studied. Analyze and test its hardness value, tensile strength, elongation retention at the break, scanning electron microscope, and oxidation induction temperature. The results show that after γ-ray irradiation, the cable hardness and the retention rate of elongation at break show a downward trend. Under the highest cumulative dose of 500kGy, the retention rate of elongation at break is greater than 50% of the failure index. The tensile strength decreases slightly, the microscopic morphology of the tensile section has holes, and the oxidation induction temperature decreases.