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| Entered date | Event description | |
|---|---|---|
| ENS 52310 | 20 October 2016 11:45:00 | The following Part 21 Report was received from the licensee via facsimile: 10 CFR Part 21 Notification - Westinghouse Life Line D Type LAC Induction Motor Model HSDP 4000V, 700hp. This is a non-emergency facsimile notification required by 10 CFR 21.21(d)(3)(i). A written notification in accordance with 10 CFR 21.21(d)(3)(ii) will be provided within 30 days. NextEra Energy Seabrook, LLC has determined there is evidence that the Westinghouse Life Line D Type LAC Induction Motor Model HSDP 4000V, 700 hp motors, original to plant construction, have a deviation from expected quality of construction. Of the four motors purchased for Unit 1, Primary Component Cooling Water (PCCW) pumps CC-P-11-D and CC-P-11-C failed after approximately 87,000 hours of operation on July 23, 2008, and November 21, 2008, due to a short caused by localized heating. On June 13, 2015, CC-P-11-B failed due to shorted windings following approximately 32,000 hours of operation. Failure analysis determined the heating was most likely caused by a turn-to-turn short circuit which led directly to the eventual failure of the entire coil-to-ground. Forensic examination identified that the coil insulation was not tightly wrapped, resulting in less than 100% resin penetration throughout the stator insulation system (i.e., voids). The voids led to poor thermal conductivity and localized hot spots that accelerated the degrading of insulation properties over time. Based on the failure analysis, it can be concluded that the undesirable coil quality is most likely attributed to workmanship, not motor design. The failure of motor insulation could cause phase-to-phase and phase-to-ground faults which ultimately would prevent motor and PCCW pump from performing their intended safety function. The identified condition appears to be a deviation from expected quality of construction and the three failures indicate that the condition is likely applicable to all the motors manufactured at the same time. The NRC Senior Resident has been notified. |
| ENS 41824 | 7 July 2005 12:51:00 | FPL Energy Seabrook Station has discovered that a condition existed that was prohibited by the Technical Specifications. The Train B Containment Building Spray Pump (CBS) was inoperable for a period of time longer than permitted by the Technical Specifications. A failed relay driver board would have prevented the Train B CBS pump from automatically starting in response to high containment pressure. Following an LOP coincident with a high containment pressure, the initial start signal from the Train B EDG emergency power sequencer would not have initiated a CBS pump start, but an automatic start signal generated at a later time in the LOP sequence would have started the pump. The failed relay driver board only inhibited automatic starting of the Train B CBS pump. The Train B EDG remained capable of providing power to other Train B loads including the automatic start of the CBS pump at the later sequence. This event is being reported in accordance with Seabrook Station Operating License condition 2.G as a failure to operate the facility in accordance with the Technical Specifications. The licensee discovered the condition during surveillance testing and the condition has been repaired. The licensee notified the NRC Resident Inspector. |