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The team identified a finding of very low The team identified a finding of very low safety significance (Green) involving a non-cited violation of 10 CFR Part 50, Appendix B, Criterion III, Design Control, in that PPL failed to verify or check the adequacy of the design of molded case circuit breakers (MCCB). The team reviewed PPL response to NRC Information Notice 93-64, Periodic Testing and Preventive Maintenance of Molded Case Circuit Breakers and determined that PPL had not included certain 125Vdc and 120Vac MCCBs in their evaluation. Subsequently the team determined that PPL had not performed any maintenance or testing on these breakers since original construction. The team found that several 125Vdc breakers were credited as one of the two isolation devises required to ensure primary containment electrical penetrations are not damaged during overload or fault conditions on the circuit. The team concluded that PPL did not verify that these safety related 125Vdc MCCBs would perform this safety function. PPL entered the issue into their corrective action program and performed an operability evaluation on the penetrations determining them to be operable but non-conforming because the second isolation device would perform the intended safety function. The team reviewed the evaluation and determined it to be reasonable. The finding was determined to be more than minor because it was associated with the Barrier Integrity Containment Design Control and Configuration Control attribute and affected the cornerstones objective. Using the NRC IMC 0609, Significance Determination Process, Appendix A, The Significance Determination Process (SDP) for Findings At-Power, Exhibit 3, Section B, the finding was determined to be of very low safety significance (Green). There was no crosscutting aspect assigned to the finding because it was not indicative of current performance.was not indicative of current performance.  +
23:59:59, 30 September 2013  +
05000387  +  and 05000388  +
23:59:59, 30 September 2013  +
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03:48:40, 28 September 2017  +
23:59:59, 30 September 2013  +
Failure to Verify Operation of Safety-Related 125Vdc Molded Case Circuit Breakers  +