ENS 53193
ENS Event | |
|---|---|
06:00 Jan 26, 2018 | |
| Title | Part-21 Notification - Improper Lugs in a Breaker Cubicle |
| Event Description | The following notification is an excerpt from the received report:
On November 30, 2017, an internal wire in a 480VAC cubicle, breaker B3424, was discovered to be terminated using incorrect size wire lugs. This deviation was identified by Monticello Nuclear Generating Plant (MNGP) electrical maintenance staff during bench testing of the cubicles in preparation for implementation of a modification. The cubicles were received by MNGP in September, 2017 from Westinghouse Electric Co. On January 26, 2017, MNGP completed an evaluation of this deviation and concluded this condition represents a significant safety hazard. As a result, this condition is a defect and is reportable pursuant to 10 CFR 21.21 (d)(4). Basic Component: Westinghouse: Eaton Breaker Cubicle Part No. 10149D92G05 On November 30, 2017, an internal wire in a 480VAC cubicle, breaker 83424, was discovered to be terminated using incorrect size wire lugs. This condition was discovered during bench testing in preparation for implementing a modification to the Control Room Ventilation (CRV) system. The wire connection was found loose and was able to be lifted off of the terminal without removing the screw. Upon further examination, the internal diameter of ring termination lugs was found to be too large, providing only a partial surface area for screw head contact. The affected lugs were on contactor coil resistor terminations internal to the cubicle. Without sufficient contact area or connection to the wiring on the resistor, control power could be lost to the contactor coil resulting in the fan V-EF-40A not starting, which would prevent proper ventilation to the room housing safety related batteries required to be operable during an accident scenario. Therefore, MNGP determined that a substantial safety hazard could have been created had the breaker cubicle been installed with the defect uncorrected. This defect was evaluated according to the station's Part 21 reporting process. The evaluation was completed on January 26, 2018 and the reporting officer was informed on January 30, 2018. Westinghouse was notified of this condition and the condition was incorporated into their corrective action program, number 100506324. The Westinghouse contact person is Adam Tokar, 724-722-6042. No further information on the vendor's corrective actions is known. MNGP entered the condition into the MNGP Corrective Action Program under 501000005918. Monticello has corrected the lugs on the installed breaker, B4423. The remaining uninstalled cubicles purchased by Monticello are being corrected in accordance with MNGP procedure MWl-8-M-4.06, Conductor Termination, prior in installation in the plant. |
| Where | |
|---|---|
| Westinghouse Electric Company Montecello, Minnesota (NRC Region 3) | |
| Organization: | Xcel Energy |
| Reporting | |
| 10 CFR 21.21(d)(3)(i), Failure to Comply or Defect | |
| Time - Person (Reporting Time:+154.38 h6.433 days <br />0.919 weeks <br />0.211 months <br />) | |
| Opened: | Steve Sollom 16:23 Feb 1, 2018 |
| NRC Officer: | Mark Abramovitz |
| Last Updated: | Feb 1, 2018 |
| 53193 - NRC Website | |
Westinghouse Electric Company with 10 CFR 21.21(d)(3)(i), Failure to Comply or Defect | |
WEEKMONTHYEARENS 573042024-09-04T23:09:0004 September 2024 23:09:00
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