NRC Information No. 88-29: Deficiencies in primary containment low-voltage electrical penetration assemblies

During an EQ inspection at Braidwood 2 conducted by Region III from February 20, 1988 to March 4, 1988, a deficiency was discovered in test documentation for four penetration assemblies. Insulation resistance readings had not been taken frequently enough to determine the performance of the assemblies in testing to simulate conditions for a loss-of-coolant accident (LOCA). The first reading was taken between 8 and 20 hours into the test. These assemblies were manufactured by the Bunker Ramo Company. In response to the finding, the licensee, Commonwealth Edison Company, provided a test report from another plant to demonstrate that the configuration installed at Braidwood 2 is environmentally qualified. A review of this test report, however, showed that the insulation resistance readings were not taken at a frequency consistent with the guidance provided in the Institute for Electronic and Electrical Engineers (IEEE) Standard 323-1974