ENS 49471
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ENS Event | |
|---|---|
09:53 Oct 24, 2013 | |
| Title | Manual Reactor Trip from Full Power Due to Feedwater System Oscillations |
| Event Description | At 0553 EDT on 10/24/2013, Oconee Unit 3 was manually tripped due to oscillations in the feedwater system in anticipation of an automatic reactor trip. At 0549 EDT, Unit 3 began experiencing small feedwater oscillations. The feedwater control system was placed in manual in an attempt to stabilize feedwater flows. Feedwater oscillations continued to grow in magnitude and at 0553 EDT, a manual trip was directed to prevent an automatic reactor trip.
Due to an RPS actuation, this event is being reported as a 4 and 8 hour9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> Non-Emergency per 10 CFR 50.72 (b)(2)(iv)(B) and 10 CFR 50.72 (b)(3) Following the reactor trip, four main steam relief valves failed to reseat. Procedure guidance was utilized to reduce main steam system pressure by approximately 30 psig to reseat the main steam relief valves. All main stream relief valves are now reseated. All other post trip conditions were normal and all other systems performed as expected. Unit 3 is currently in Mode 3 and stable. Operations have been stabilized on Unit 3. A post-trip investigation is in progress, per site procedures and directives. The licensee has notified the NRC Resident Inspector.
Duke Energy reviewed NRC Event 49471 against NUREG 1022, Rev 3, section 3.2.6, "System Actuation" and determined this event should have been reported only per 10 CFR 50.72 (b)(2)(iv)(B), RPS Actuation (while critical). Thus, Duke Energy is revising NRC Event 49471 to remove the 8-hour report criteria 10 CFR 50.72 (b)(2)(iv)(A). The NRC Resident Inspector was notified of this revised report. This update has no effect on safety significance. Notified R2DO (Shaeffer). |
| Where | |
|---|---|
Oconee  South Carolina (NRC Region 2) | |
| Reporting | |
| 10 CFR 50.72(b)(2)(iv)(B), RPS Actuation | |
| LER: | 05000287/LER-2013-001 Re Manual Reactor Trip Due to Main Feedwater Flow Oscillations |
| Time - Person (Reporting Time:+-0.13 h-0.00542 days <br />-7.738095e-4 weeks <br />-1.78074e-4 months <br />) | |
| Opened: | Mike Tate 09:45 Oct 24, 2013 |
| NRC Officer: | Bill Huffman |
| Last Updated: | Sep 10, 2014 |
| 49471 - NRC Website
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Unit 3 | |
|---|---|
| Reactor critical | Critical |
| Scram | Yes, Manual Scram |
| Before | Power Operation (100 %) |
| After | Hot Standby (0 %) |
WEEKMONTHYEARENS 557502022-02-22T03:07:00022 February 2022 03:07:00
[Table view]10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Manual Reactor Trip ENS 557332022-02-05T08:57:0005 February 2022 08:57:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(a)(1)(i), Emergency Class Declaration Unusual Event Declared Due to Visual Observation of Smoke and Multiple Fire Alarms in the West Penetration Room ENS 556382021-12-10T05:49:00010 December 2021 05:49:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation Automatic Reactor Trip ENS 546612020-04-11T01:25:00011 April 2020 01:25:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation Manual Reactor Trip ENS 536772018-10-19T04:00:00019 October 2018 04:00:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Turbine Steam Seal Header Pressure Malfunction ENS 533292018-04-13T06:27:00013 April 2018 06:27:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation Manual Reactor Trip Following Main Feedwater Control Problem ENS 528702017-07-24T20:38:00024 July 2017 20:38:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation Automatic Reactor Trip Due to Load Rejection ENS 517702016-03-06T20:20:0006 March 2016 20:20:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(a)(1)(i), Emergency Class Declaration Emergency Declaration Due to Fire/Explosion in the Main Transformer ENS 507812015-01-31T19:31:00031 January 2015 19:31:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation Manual Rps Actuation Due to Oscillations in the Feedwater System ENS 494712013-10-24T09:53:00024 October 2013 09:53:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation Manual Reactor Trip from Full Power Due to Feedwater System Oscillations ENS 461592010-08-07T18:51:0007 August 2010 18:51:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Manual Reactor Trip After Reactor Coolant Pumps High Vibration ENS 450882009-05-22T00:15:00022 May 2009 00:15:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation Rps Actuation (Reactor Trip) Due to Generator Phase Differential Lockout ENS 446382008-11-07T13:34:0007 November 2008 13:34:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Automatic Reactor Trip ENS 441092008-03-31T17:52:00031 March 2008 17:52:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Automatic Reactor Trip on Turbine Trip During Maintenance Activities ENS 431692007-02-15T21:54:00015 February 2007 21:54:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Unit 1 and Unit 2 Reactor Trip ENS 424932006-04-12T17:35:00012 April 2006 17:35:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation Unit 2 Experienced an Automatic Reactor Trip Following the Loss of the "2B2" Reactor Coolant Pump ENS 419662005-08-31T18:28:00031 August 2005 18:28:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation, 10 CFR 50.72(b)(2)(i), Tech Spec Required Shutdown, 10 CFR 50.72(b)(2)(iv)(A), System Actuation - ECCS Discharge Unit 3 Experienced an Automatic Reactor Trip During Routine Testing ENS 405482004-02-26T16:51:00026 February 2004 16:51:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation Rps Actuation While Critical 2022-02-05T08:57:00 | |
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