Implementation of New Cable Condition-Monitoring Technology at Oyster Creek Nuclear Generating Station

This paper reports the results of in situ cable testing performed at the Oyster Creek Nuclear Generating Station in September 2016 to assess the aging condition of a number of cables as installed in the plant. Despite having been in service for over 40 years, our results found that these cables still met their qualification criteria, were in good working condition, and could continue to serve the plant for the foreseeable future. Some degradation in the cable insulation was noted but not as much as one would expect after more than 40 years of service in a nuclear power plant. Specifically, test results revealed that 10% of cables exhibited a noticeable degree of degradation, 30% were only slightly degraded, and the remaining 60% were essentially unaffected by aging. In the case of jacketed cables, which were assessed using walkdowns performed by the plant's personnel, almost all aging and degradation were limited to the jacket material while the underlying cable insulation was largely unaffected. This is consistent with laboratory test results, which have shown that jacket material, especially Neoprene and Hypalon, degrade much faster than cross-linked polyethylene (XLPE) and other materials that are used for primary cable insulation.