ENS 51079
ENS Event | |
|---|---|
17:06 Mar 17, 2015 | |
| Title | Invalid Actuation of Auxiliary Feedwater System During Electrical Testing |
| Event Description | This 60-day telephone notification is being submitted in accordance with paragraphs 10 CFR 50.73(a)(1) and 50.73(a)(2)(iv)(A) to report an invalid actuation of the Auxiliary Feedwater (AFW) system at Watts Bar Nuclear Plant Unit 1.
On March 17, 2015, at 1306 EDT, Watts Bar Unit 1 was in Mode 1 at 100% power, when during the performance of 6.9 Kv phase verifications for the FLEX Diesel Generator, maintenance technicians were installing a multimeter (Simpson 260 Series) which resulted in starting the Unit 1 train B: motor-driven auxiliary feedwater pump, centrifugal charging pump, component cooling pump and thermal barrier booster pump, and isolated steam generator 1 and 3 blowdown. A secondary 6 ampere fuse opened due to an overcurrent and actuated (dropped-out) the associated blackout relays which started the identified pumps. At the time of the event, the train B standby diesel generator was removed from service for maintenance. The 6.9 Kv shutdown board did not lose power during the event and safety injection system and standby diesel generator features were not actuated. The maintenance technicians performing the phase verifications immediately recognized that several supply breakers had closed after the last test lead was connected and promptly reported the event to the control room. Work was halted and TVA conducted a prompt investigation. While not conclusive, it is likely that the maintenance technicians created a shunt or ground condition while installing test equipment, causing a circuit overcurrent which opened the fuse, activating the black-out relays and actuating the identified pumps and valves. Plant operators responded appropriately to the event and the applicable Technical Specification Required Actions were exited at 1612 EDT, when equipment restoration had been completed. TVA is continuing to evaluate this event in accordance with the corrective action program (reference: PER nos.1003213 and 1027101). The NRC Resident Inspector has been notified. |
| Where | |
|---|---|
Watts Bar  Tennessee (NRC Region 2) | |
| Reporting | |
| 10 CFR 50.73(a)(1), Submit an LER, Invalid Actuation | |
| Time - Person (Reporting Time:+1486.65 h61.944 days <br />8.849 weeks <br />2.036 months <br />) | |
| Opened: | Brian Mcilnay 15:45 May 18, 2015 |
| NRC Officer: | Steve Sandin |
| Last Updated: | May 18, 2015 |
| 51079 - NRC Website
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Unit 1 | |
|---|---|
| Reactor critical | Critical |
| Scram | No |
| Before | Power Operation (100 %) |
| After | Power Operation (100 %) |
WEEKMONTHYEARENS 570772024-02-16T02:24:00016 February 2024 02:24:00
[Table view]10 CFR 50.73(a)(1), Submit an LER Invalid Actuation of Emergency Diesel Generators ENS 562742022-11-24T21:21:00024 November 2022 21:21:00 10 CFR 50.73(a)(1), Submit an LER 60-DAY Optional Telephonic Notification of Invalid Actuation of Containment Ventilation Isolation Valves ENS 548702020-07-23T13:56:00023 July 2020 13:56:00 10 CFR 50.73(a)(1), Submit an LER 60-Day Optional Telephonic Notification for Two Invalid Containment Ventilation Isolation Actuations ENS 542202019-07-26T14:03:00026 July 2019 14:03:00 10 CFR 50.73(a)(1), Submit an LER Invalid Containment Ventilation Isolation Actuation ENS 538402018-12-02T05:28:0002 December 2018 05:28:00 10 CFR 50.73(a)(1), Submit an LER Invalid Containment Ventilation Isolation Actuation ENS 527902017-04-28T09:00:00028 April 2017 09:00:00 10 CFR 50.73(a)(1), Submit an LER 60-Day Optional Telephonic Notification for an Invalid Auxiliary Feedwater Actuation ENS 525392016-12-15T18:32:00015 December 2016 18:32:00 10 CFR 50.73(a)(1), Submit an LER 60 Day Optional Telephonic Notification for an Invalid Containment Ventilation Isolation Actuation ENS 520012016-04-14T18:06:00014 April 2016 18:06:00 10 CFR 50.73(a)(1), Submit an LER 60-Day Optional Telephonic Notification for an Invalid Containment Vent Isolation Actuation ENS 511522015-04-15T16:07:00015 April 2015 16:07:00 10 CFR 50.73(a)(1), Submit an LER Invalid Actuations of the Containment Ventilation Isolation System ENS 510792015-03-17T17:06:00017 March 2015 17:06:00 10 CFR 50.73(a)(1), Submit an LER Invalid Actuation of Auxiliary Feedwater System During Electrical Testing ENS 501332014-04-16T05:48:00016 April 2014 05:48:00 10 CFR 50.73(a)(1), Submit an LER 60-Day Optional Telephonic Notification for Inadvertent Fast Start of Diesel Generator During Testing ENS 482042012-06-19T03:49:00019 June 2012 03:49:00 10 CFR 50.73(a)(1), Submit an LER Invalid Actuation of Containment Ventilation Isolation ENS 441602008-02-23T04:00:00023 February 2008 04:00:00 10 CFR 50.73(a)(1), Submit an LER 60-Day Verbal Notification of Invalid Specified System Actuation ENS 411832004-09-15T14:14:00015 September 2004 14:14:00 10 CFR 50.73(a)(1), Submit an LER Invalid Actuation of Containment Vent Isolation Valve 2024-02-16T02:24:00 | |