ENS Event | |
|---|---|
13:00 Oct 20, 2011 | |
| Title | Inoperable Emergency Feedwater Pump Potentially Impacts Rhr Safety Function |
| Event Description | At 08:00 CDT on 10/20/2011 Essential Chilled Water Loop B was declared inoperable while turbine driven Emergency Feedwater Pump AB was out of service for planned maintenance. Operability of Essential Chilled Water Loop B was restored at 08:50. During this time period, the application of cascading technical specifications rendered motor driven Emergency Feedwater Pump B inoperable. The remaining operable Emergency Feedwater Pump A is a design rated 50 percent pump; therefore, this event could have prevented fulfillment of the Residual Heat Removal safety function. Offsite power and Train A safety related equipment and systems were verified operable.
Essential Chilled Water Loop B was declared inoperable because Essential Chiller B failed to automatically restart from a load recycle. The shift crew took action to align Essential Chiller AB to restore operability to Essential Chilled Water Loop B. The cause for the failure of Essential Chiller B is not yet known. Restoration of operability to Essential Chilled Water Loop B concurrently restored operability to Emergency Feedwater Pump B. No plant transient or safety system actuations occurred. Plant operation continues stable at 100 percent power. The licensee notified the NRC Resident Inspector. |
| Where | |
|---|---|
Waterford  Louisiana (NRC Region 4) | |
| Reporting | |
| 10 CFR 50.72(b)(3)(v)(B), Loss of Safety Function - Remove Residual Heat | |
| LER: | 05000382/LER-2011-005 Regarding a Malfunction of the Essential Chilled Water Loop B |
| Time - Person (Reporting Time:+1.53 h0.0638 days <br />0.00911 weeks <br />0.0021 months <br />) | |
| Opened: | Brian Gordon 14:32 Oct 20, 2011 |
| NRC Officer: | Pete Snyder |
| Last Updated: | Oct 20, 2011 |
| 47361 - NRC Website
Loading map... | |
Unit 3 | |
|---|---|
| Reactor critical | Critical |
| Scram | No |
| Before | Power Operation (100 %) |
| After | Power Operation (100 %) |
WEEKMONTHYEARENS 503782014-08-18T13:53:00018 August 2014 13:53:00
[Table view]10 CFR 50.72(b)(3)(v)(B), Loss of Safety Function - Remove Residual Heat, 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident Ultimate Heat Sink System Inoperable ENS 473612011-10-20T13:00:00020 October 2011 13:00:00 10 CFR 50.72(b)(3)(v)(B), Loss of Safety Function - Remove Residual Heat Inoperable Emergency Feedwater Pump Potentially Impacts Rhr Safety Function 2014-08-18T13:53:00 | |