Condition Assessment of NPP Cables Through Indenter Modulus and Break-Elongation Test

Class IE electric cables can generally withstand 40 years of degradation from predicted operational environments and still perform safety-related functions even during and after accidents. These cables degrade through deterioration of insulation material, possibly leading to mechanical and electrical failure after decades of operation. The elongation at break is usually used as the critical parameter. However, elongation testing is destructive and requires relatively large specimens, making it undesirable for analyzing installed cables. In this paper, indenter modulus and break-elongation test for condition assessment of NPP cables were performed after accelerated ageing under heating and radiation. The test results showed that the relation between break-elongation and indenter modulus, and concluded that Indenter modulus can be effectively used to condition assessment of NPP cable ageing degradation.