ENS 50539
ENS Event | |
|---|---|
20:08 Aug 12, 2014 | |
| Title | Part 21 - Defective Allen Bradley Relay |
| Event Description | This is a non-emergency notification from Waterford 3 required under 10 CFR PART 21 concerning the deviation of a dedicated basic component from manufacturing specifications, which could have possibly caused a substantial safety hazard.
On 04/23/2014, Control Room Emergency Filtration Unit A automatically started unexpectedly. It was determined that the equipment inadvertent actuation occurred due to an Allen Bradley Type 700RTC relay failure. The failure mode resulted in the associated equipment actuating as it would to perform its safety function, not adversely impacting steady state plant operations. The failed relay was replaced on 4/25/2014. Independent failure analysis performed by Southwest Research Institute (SwRI) on an Allen Bradley model 700RTC000020U1 relay that failed in service at Waterford 3 Nuclear Station (WF3) identified that the relay's L22 coil was electrically open. Detailed destructive analysis of the L22 coil revealed corrosion of the winding in multiple locations. Corrosion products removed from various locations near the failure site on the L22 coil contained significant concentrations of chlorine. The independent failure analysis concluded the in-plant failure observed at Waterford 3 was caused by corrosion near the start end of the relay's L22 coil winding. The source of the corrosive material that damaged the winding was not apparent; however, based on review of storage practices at Waterford 3, it is likely that it was introduced during manufacture of the coil. On 8/12/2014, Waterford 3 engineering determined this relay condition was a PART 21 deviation. The qualifying vendor (Qual Tech NP) has been contacted and they have provided the completed failure analysis to the manufacturer (Allen Bradley). Entergy concluded that for the application of this relay where a malfunction occurred, it did not result in a substantial safety hazard. However, on 10/10/2014, at approximately 1233 CDT, Entergy completed an evaluation concluding that had this relay type been installed, with the same deviation, in other safety related normally energized applications, it could possibly have resulted in a substantial safety hazard, and thus is a PART 21 defect. The Waterford 3 Site VP was informed 10/14/2014. The NRC Resident Inspector has been notified. |
| Where | |
|---|---|
| Allen Bradley Killona, Louisiana (NRC Region 4) | |
| Organization: | Waterford Steam Electric Station |
| Reporting | |
| 10 CFR 21.21(d)(3)(i), Failure to Comply or Defect | |
| Time - Person (Reporting Time:+1534.03 h63.918 days <br />9.131 weeks <br />2.101 months <br />) | |
| Opened: | Carl Rich 18:10 Oct 15, 2014 |
| NRC Officer: | Daniel Mills |
| Last Updated: | Oct 15, 2014 |
| 50539 - NRC Website | |
Allen Bradley with 10 CFR 21.21(d)(3)(i), Failure to Comply or Defect | |
WEEKMONTHYEARENS 510302015-04-30T05:00:00030 April 2015 05:00:00
[Table view]10 CFR 21.21(d)(3)(i), Failure to Comply or Defect Potentially Unqualified Component in Certain Allen Bradley Timing Relays ENS 505392014-08-12T20:08:00012 August 2014 20:08:00 10 CFR 21.21(d)(3)(i), Failure to Comply or Defect Part 21 - Defective Allen Bradley Relay 2015-04-30T05:00:00 | |