Irradiation ageing of CSPE/EPR control command electric cables. Correlation between mechanical properties and oxidation

In this paper, correlations between the elongation at break and the oxidation of chlorosulfonated polyethylene and ethylene propylene rubber (EPR) polymers in instrumentation and control cables irradiated at different dose rates are brought to evidence. During irradiation, the following phenomena are observed: an increase of oxygen consumption, a degradation of the mechanical properties and a reduction of the oxidation induction time (OIT) measured for EPR.

A correlation between the mechanical properties and the OIT of the EPR has only been established in the case of irradiation at low dose rate. This reveals a difference in the oxidative degradation process at low and high dose rates. This study shows the possibility to assess the ageing of electric cables installed inside nuclear power plants by OIT measurements.