Evaluation method of deterioration of polyetheretherketone using dielectric relaxation characteristics

A novel deterioration evaluation method of class 1E cable insulation, Polyetheretherketone (PEEK), are proposed by using dielectric relaxation characteristic in order to evaluate the deterioration process for the accelerated aged PEEK. The procedure of accelerated ageing consists of 3 steps, ⁶⁰Co gamma-ray irradiation, thermal ageing, and loss of coolant accident (LOCA) simulation. Also, the proposed evaluation method was compared with the standardized method, elongation at break, and subsidiary methods, which are weight loss temperature, the carbonyl group concentration, indenter modulus. The novel proposed evaluation method using dielectric relaxation characteristic will be applicable to classification of environmental qualification (EQ), and contribute to the reliability of the life span extension in the nuclear power plants.