All I can say is think about the Boeing 737 max problem. Basically the whole Boeing organization and regulators went crazy over financial pressures.
Report Section
Mitigating Systems
Green NCV 05000277,05000278/2019003-01 Open/Closed
[P.3] - Resolution
71152
The inspectors identified a self-revealing, Green non-cited violation (NCV) associated with Title 10 of the Code of Federal Regulations (CFR) Part 50, Appendix B, Criterion XVI, “Corrective Action,” because Exelon did not identify and correct a condition adverse to quality associated with the E-1 emergency diesel generator (EDG). Specifically, Exelon did not implement their cable monitoring program testing on the E-1 diesel and, as a result, did not identify a condition adverse to quality associated with an underground cable prior to its failure during a surveillance test on May 29, 2019, which resulted in the E-1 diesel being declared inoperable. Description: Peach Bottom has four EDGs that supply emergency power (4kV) to both Unit 2 and Unit 3. The electricity is transferred from the generator through nine aluminum conductors, underground from the EDG building to the turbine building. The E-1 diesel provides emergency power to the E-11 and E-12 safety busses.
During a monthly surveillance run of the E-1 EDG on May 29, 2019, the engine was running for approximately 30 seconds, unloaded with the field flashed, when it unexpectedly tripped from an overcurrent protection relay. The E-1 diesel was immediately declared inoperable and Exelon commenced troubleshooting. Exelon determined, through cable testing, that the cause of the trip was a faulted ‘B’ phase cable that connected the generator to the 4kV breaker. Due to parts availability and limiting condition for operation time constraints, Exelon performed a temporary modification to abandon the ‘B’ phase cables and reduce the number of energized conductors from nine to six. Exelon performed an engineering analysis to conclude that the remaining six conductors had sufficient capacity to support the maximum diesel loading. Exelon restored the diesel to operable on June 2, 2019.
Exelon entered the E-1 cable fault condition into the CAP under issue report (IR) 4256520 and performed a root cause evaluation. The root cause evaluation determined that the direct cause of the failure was degraded cable insulation likely due to the cables being exposed to adverse environmental conditions for an extended period of time. It further concluded that the engineering cable program owners and their managers did not effectively use the CAP to identify and resolve gaps in the cable program prior to the E-1 EDG cable failure. Specifically, the cable monitoring program, ER-AA-300-150, requires the station to perform tan-delta testing of the EDG cables and at the time of failure, these cables had not yet been tested in accordance with the frequency required by the program. Tan-delta testing is an industry-accepted method of testing the health of insulation for electrical power cables. The station had originally attempted testing of the cables in 2013; however, they were unsuccessful due to perceived interference with the test equipment as documented in IR 1511027. This IR was closed to a work order (WO) that was never performed. Furthermore, in 2016, a self-assessment discovered that the 2013 WO was inappropriately closed out and created IR 2651755; however, no WO was created from this IR. Again, in 2017, Exelon identified that the 2016 WO was not created and created IR 3963696. Under this IR, Exelon created an action tracking assignment to reschedule the cable testing...
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