Aging, condition monitoring, and loss-of-coolant accident (LOCA) tests of Class 1E electrical cables: Summary of results

This paper summarizes the results of aging, condition monitoring, and accident testing of various nuclear power plant cable products. Four sets of cables were aged under simultaneous thermal (≅95C) and radiation (≅0.10 kGy/hr) conditions. One set of cables was aged for 3 months, a second set was aged for 6 months, a third set was aged for 9 months, and a fourth set was not aged. A sequential accident consisting of high dose rate irradiation (≅6 kGy/hr) and high temperature steam was then performed on each set of cables. The results of the tests indicate that the feasibility of life extension of some popular cable products is promising. Mechanical measurements, primarily elongation, modulus, and density, were more effective than electrical measurements for monitoring age-related degradation. The broad objectives of this experimental program were twofold: (a) to determine the life extension potential of popular cable products used in nuclear power plants and (b) to determine the potential of condition monitoring for residual life assessment