ENS Event | |
|---|---|
08:23 Nov 3, 2013 | |
| Title | 60-Day Report Involving an Invalid Partial Actuation of Unit 1 Edg "1A" Due to a Failed Relay |
| Event Description | This report is being made under 10 CFR 50.73(a)(2)(iv)(A) as an invalid actuation of Emergency Diesel Generator (EDG) 1A in lieu of a 60-day LER. Per NUREG-1022, the following information is provided:
The specific train and system that were actuated: At 0323 hours0.00374 days <br />0.0897 hours <br />5.340608e-4 weeks <br />1.229015e-4 months <br /> [EST] on November 3, 2013, the St. Lucie Unit 1 train 'A' EDG automatically started. Troubleshooting revealed that the ESF-A group 7 actuation relay (K507A) failed, providing an invalid Engineered Safety Feature (ESF) 'start' signal to EDG 1A, and the EDG started and operated in the standby mode. The failed relay was replaced, and the post maintenance test was successful. Was train actuation complete or partial? This was a partial actuation of the 'A' train emergency power system as the 1A EDG output breaker did not close, by design, with power on the emergency busses. Did the system start and function correctly? The failed 7A actuation relay provided an invalid start signal to EDG 1A that properly responded to the start signal. The EDG output breaker closing logic prevented closure because the 4160 VAC emergency bus was energized at the time the actuation relay failed. The system started and functioned as would be expected for the existing plant conditions. The licensee informed the NRC Resident Inspector. Notified R2DO (Haag). |
| Where | |
|---|---|
Saint Lucie  Florida (NRC Region 2) | |
| Reporting | |
| 10 CFR 50.73(a)(1), Submit an LER, Invalid Actuation | |
| Time - Person (Reporting Time:+1443.85 h60.16 days <br />8.594 weeks <br />1.978 months <br />) | |
| Opened: | Reese Kilian 12:14 Jan 2, 2014 |
| NRC Officer: | Steve Sandin |
| Last Updated: | Jan 2, 2014 |
| 49688 - NRC Website
Loading map... | |
Unit 1 | |
|---|---|
| Reactor critical | Not Critical |
| Scram | No |
| Before | Hot Standby (0 %) |
| After | Hot Standby (0 %) |
WEEKMONTHYEARENS 511952015-05-05T00:27:0005 May 2015 00:27:00
[Table view]10 CFR 50.73(a)(1), Submit an LER Invalid Auxiliary Feedwater Actuation System Partial Actuation ENS 496882013-11-03T08:23:0003 November 2013 08:23:00 10 CFR 50.73(a)(1), Submit an LER 60-Day Report Involving an Invalid Partial Actuation of Unit 1 Edg "1A" Due to a Failed Relay 2015-05-05T00:27:00 | |