ENS Event | |
|---|---|
03:00 Nov 30, 2012 | |
| Title | 60-Day Optional Telephonic Notification of Invalid System Actuation |
| Event Description | This telephone notification is being made for an invalid actuation in accordance with 10 CFR 50.73(a)(2)(iv)(A) following the reporting guidance of 10 CFR 50.73(a)(1) and is not considered a Licensee Event Report.
With Unit 2 at Cold Shutdown (about 105?F and depressurized), an invalid actuation of the Main Feedwater (FW) isolation occurred at 2200 [EST] during removal of the 'A' Train Hi Consequence Limiting Safeguards (CLS) fuses. This action caused the 'A' train FW isolation relay to actuate and, as designed, tripped the operating 'B' Main Feed Pump (MFP) and the Main Turbine, which was latched for testing. The 'A' MFP was not in operation at the time of the event. This was a partial actuation of the SI system. SI signals were inhibited prior to removal of the Hi CLS fuses by the tagging of the lead connecting the Hi CLS relay to the SI master relay. Although FW isolation occurs with SI actuation, the relay associated with the FW isolation circuitry is separately actuated and had not been tagged out. When the Hi CLS fuses were removed, the FW isolation relay was energized. Plant systems and components responding to the signal started and functioned as designed with the exception of those inhibited by tag out. The affected components were restored to their pre-event configuration, The action to determine and initiate corrective actions is complete, and the necessary procedures are under revision. The licensee notified the NRC Resident Inspector. |
| Where | |
|---|---|
Surry  Virginia (NRC Region 2) | |
| Reporting | |
| 10 CFR 50.73(a)(1), Submit an LER, Invalid Actuation | |
| Time - Person (Reporting Time:+992.07 h41.336 days <br />5.905 weeks <br />1.359 months <br />) | |
| Opened: | Barry Garber 11:04 Jan 10, 2013 |
| NRC Officer: | Donald Norwood |
| Last Updated: | Jan 10, 2013 |
| 48662 - NRC Website
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Unit 2 | |
|---|---|
| Reactor critical | Not Critical |
| Scram | No |
| Before | Cold Shutdown (0 %) |
| After | Cold Shutdown (0 %) |
WEEKMONTHYEARENS 486622012-11-30T03:00:00030 November 2012 03:00:00
[Table view]10 CFR 50.73(a)(1), Submit an LER 60-Day Optional Telephonic Notification of Invalid System Actuation ENS 486612012-11-29T04:05:00029 November 2012 04:05:00 10 CFR 50.73(a)(1), Submit an LER 60-Day Optional Telephonic Notification of Invalid System Actuation ENS 464342010-10-27T03:56:00027 October 2010 03:56:00 10 CFR 50.73(a)(1), Submit an LER Invalid Actuation of High Consequence Limiting Safeguards and Safety Injection Systems ENS 447292008-10-29T23:04:00029 October 2008 23:04:00 10 CFR 50.73(a)(1), Submit an LER 60 Day Report - Invalid System Actuation 2012-11-30T03:00:00 | |