ENS 46544
ENS Event | |
|---|---|
07:45 Nov 18, 2010 | |
| Title | Invalid Actuation of Motor Driven Emergency Feedwater System |
| Event Description | This report is being made per paragraphs 50.73(a)(1) and 50.73(a)(2)(iv)(A) to address an actuation of the Emergency Feedwater (EFW) System on Oconee Unit 3 on 11/18/10 while moving the 3A Motor Driven EFW Pump (MD EFWP) control switch from position 'Auto 1' to 'Auto 2.' EFW is a system named in 50.73(a)(2)(iv)(B).
The 3A MD EFWP was inadvertently started during operation of the control switch in the Oconee Unit 3 Control Room. The start signal was a manual start when the operator moved the control switch beyond the intended position. The functioning/behavior of the MD EFWP control switch and human error are being investigated in the site corrective action program. This is considered an INVALID signal with respect to 50.73(a)(2)(iv)(A). The manual start only affected the 3A MD EFWP. On 11/18/10, a Unit 3 startup from a refueling outage was in progress. Unit 3 was in Mode 3. While performing a step in OP/3/A/1102/001 (Controlling Procedure for Unit Startup), the Operator inadvertently started 3A MD EFWP when positioning 3A MD EFWP control switch from position 'Auto 1' to 'Auto 2.' Specific Information Required per NUREG 1022: (a) The specific train(s) and system(s) that were actuated: The specific train(s) and system(s) that were actuated was the 3A MD EFWP and the A train of EFW. The 3B MD EFWP and the Turbine Driven EFW Pump were not affected by this event. (b) Whether each train actuation was complete or partial: The manual actuation was considered complete (i.e. all necessary components responded to the start signal to provide EFW to the Steam Generator (SG). The A train control valve (3FDW-315) was open, as expected for the evolutions in progress. This allowed EFW to reach the SG. C) Whether or not the system started and functioned successfully: The 3A MD EFWP and train started and operated successfully until secured by Operations personnel. Initial Safety Significance: None, there was no significant transient. Corrective Action(s): EFDW was secured within approximately one minute by placing 3A MD EFWP control switch in the Auto 2 position. This event has been entered into the site corrective action program for resolution. The licensee notified the NRC Resident Inspector. |
| Where | |
|---|---|
Oconee  South Carolina (NRC Region 2) | |
| Reporting | |
| 10 CFR 50.73(a)(1), Submit an LER, Invalid Actuation | |
| Time - Person (Reporting Time:+1377.57 h57.399 days <br />8.2 weeks <br />1.887 months <br />) | |
| Opened: | Randy Todd 17:19 Jan 14, 2011 |
| NRC Officer: | Vince Klco |
| Last Updated: | Jan 14, 2011 |
| 46544 - NRC Website
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Unit 3 | |
|---|---|
| Reactor critical | Not Critical |
| Scram | No |
| Before | Hot Standby (0 %) |
| After | Hot Standby (0 %) |
WEEKMONTHYEARENS 480302012-04-23T00:58:00023 April 2012 00:58:00
[Table view]10 CFR 50.73(a)(1), Submit an LER Keowee Hydro Power Station Automatically Started Based on an Invalid Signal ENS 465442010-11-18T07:45:00018 November 2010 07:45:00 10 CFR 50.73(a)(1), Submit an LER Invalid Actuation of Motor Driven Emergency Feedwater System ENS 451802009-05-19T20:09:00019 May 2009 20:09:00 10 CFR 50.73(a)(1), Submit an LER Invalid Feedwater System Actuation While Shutdown ENS 431462006-12-09T02:43:0009 December 2006 02:43:00 10 CFR 50.73(a)(1), Submit an LER Invalid Efw Actuations Due to an Issue in Sg Dryout Protection Circuit ENS 416492005-04-29T05:05:00029 April 2005 05:05:00 10 CFR 50.73(a)(1), Submit an LER Emergency Hydro Generators Auto Start - Unknown Cause ENS 406862004-03-20T19:59:00020 March 2004 19:59:00 10 CFR 50.73(a)(1), Submit an LER Invalid Actuation of the Motor Driven Emergency Feedwater Pumps 2012-04-23T00:58:00 | |