ENS Event | |
|---|---|
10:09 Nov 14, 2010 | |
| Title | Invalid Actuation of Turbine Driven Auxiliary Feedwater Pump |
| Event Description | This report is a 60-day telephone notification in lieu of written LER being made under 10CFR50.73(a)(2)(iv)(A) and 10CFR50.73(a)(1). The event was an invalid actuation of the Unit 1 turbine driven auxiliary feedwater (TDAFW) pump.
At 0509 EST on 11/14/2010, during testing of the 1B main feedwater pump (MFP), the TDAFW pump started and the motor driven auxiliary feedwater (MDAFW) valves received a signal to go to automatic control. An investigation determined that during previous testing of the 1A MFP, the 1A MFP trip relay (RTT-1) remained stuck in the trip condition. The stuck relay on the 1A MFP and the trip test on 1B MFP made up the logic for a TDAFW and MDAFW start from both MFPs tripped signal. The 1A MFP trip relay was replaced. The Unit 1A and B train MDAFW and TDAFW system received the actuation signal. The 1A and 1B MDAFW pumps were already in service at the time for Mode 3 operation. Actual plant conditions did not exist that required an automatic start of the auxiliary feedwater system. Therefore, this actuation was invalid. A complete train actuation occurred and the auxiliary feedwater system functioned successfully. The licensee has notified the NRC Resident Inspector. |
| Where | |
|---|---|
Sequoyah  Tennessee (NRC Region 2) | |
| Reporting | |
| 10 CFR 50.73(a)(1), Submit an LER, Invalid Actuation | |
| Time - Person (Reporting Time:+923.4 h38.475 days <br />5.496 weeks <br />1.265 months <br />) | |
| Opened: | Dennis Dimopoulos 21:33 Dec 22, 2010 |
| NRC Officer: | John Knoke |
| Last Updated: | Dec 22, 2010 |
| 46504 - NRC Website
Loading map... | |
Unit 1 | |
|---|---|
| Reactor critical | Not Critical |
| Scram | No |
| Before | Hot Standby (0 %) |
| After | Hot Standby (0 %) |
WEEKMONTHYEARENS 573132024-08-03T12:40:0003 August 2024 12:40:00
[Table view]10 CFR 50.73(a)(1), Submit an LER 60-DAY Notification of Invalid Specified System Actuation ENS 551302021-01-11T16:52:00011 January 2021 16:52:00 10 CFR 50.73(a)(1), Submit an LER 60-Day Optional Telephonic Notification for Invalid Containment Ventilation Isolation Actuation ENS 514512015-08-07T23:19:0007 August 2015 23:19:00 10 CFR 50.73(a)(1), Submit an LER 60-Day Optional Telephone Notification for an Invalid Containment Isolation Activation ENS 511172015-04-12T17:20:00012 April 2015 17:20:00 10 CFR 50.73(a)(1), Submit an LER 60-Day Optional Telephonic Notification for an Invalid Containment Isolation Activation. ENS 470222011-06-04T19:17:0004 June 2011 19:17:00 10 CFR 50.73(a)(1), Submit an LER Invalid Specified System Actuation Caused All 4 Emergency Diesel Generators to Start ENS 472492011-05-05T19:20:0005 May 2011 19:20:00 10 CFR 50.73(a)(1), Submit an LER Invalid Specified System Actuation ENS 465042010-11-14T10:09:00014 November 2010 10:09:00 10 CFR 50.73(a)(1), Submit an LER Invalid Actuation of Turbine Driven Auxiliary Feedwater Pump ENS 450852009-04-09T05:15:0009 April 2009 05:15:00 10 CFR 50.73(a)(1), Submit an LER Optional 60-Day Telephone Report of an Invalid Start of All Four Emergency Diesel Generators 2024-08-03T12:40:00 | |