ENS 46313
ENS Event | |
|---|---|
04:13 Oct 7, 2010 | |
| Title | Automatic Reactor Trip Due to a One Loop Reactor Coolant Low Flow |
| Event Description | At 0013 hours1.50463e-4 days <br />0.00361 hours <br />2.149471e-5 weeks <br />4.9465e-6 months <br /> EDT on October 7, 2010, with the unit in Mode 1 at 100% power, an automatic reactor trip occurred. The reactor trip signal was based on the One Loop Low Flow reactor protection function. Reactor Coolant Pump (RCP) 'C' tripped during the event.
The Auxiliary Feedwater System automatically actuated, as expected due to low steam generator water level, and provided feedwater to the steam generators. Steam generator and pressurizer Power Operated Relief Valves (PORVs) and Main Steam Safety Valves did not open during the event. All control rods indicated fully inserted following the reactor trip. The normal post-trip electrical lineup is providing power to the plant and the electrical system is stable. Decay heat is being removed via the condenser. The reactor is currently stable in Mode 3. The Main Turbine Lube Oil Deluge System actuated without a fire during the event. A fire hose station pipe ruptured after the deluge system actuation. The fire hose station was isolated. In addition, the 'B' Main Feedwater (MFW) Pump tripped during the event and the 'A' Main Feedwater pump subsequently tripped due to high steam generator level in the 'C' Steam Generator at about 0023 hours2.662037e-4 days <br />0.00639 hours <br />3.80291e-5 weeks <br />8.7515e-6 months <br />. There is currently indication of RCP 'C' Number 2 seal leakage of approximately 2.5 gpm. At approximately 0405 EDT the Auxiliary Feedwater (AFW) system actuated due to a trip of MFW Pump 'A' while attempting to start the pump in accordance with procedure GP-004, Post Trip Stabilization. The AFW system actuation signal caused motor-driven AFW Pump 'B' to start. The motor-driven AFW Pump 'A' was already in operation due to the post-trip condition. The cause of the MFW Pump 'A' trip is under investigation. This AFW system actuation is being reported in accordance with 10 CFR 50.72(b)(3)(iv)(A). The cause of the reactor trip is under investigation. The licensee notified the NRC Resident Inspector. |
| Where | |
|---|---|
Robinson  South Carolina (NRC Region 2) | |
| Reporting | |
| 10 CFR 50.72(b)(2)(iv)(B), RPS Actuation 10 CFR 50.72(b)(3)(iv)(A), System Actuation | |
| LER: | 05000261/LER-2010-009 |
| Time - Person (Reporting Time:+-0.12 h-0.005 days <br />-7.142857e-4 weeks <br />-1.64376e-4 months <br />) | |
| Opened: | Garrett Sanders 04:06 Oct 7, 2010 |
| NRC Officer: | Vince Klco |
| Last Updated: | Oct 7, 2010 |
| 46313 - NRC Website
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Unit 2 | |
|---|---|
| Reactor critical | Critical |
| Scram | A/R |
| Before | Power Operation (100 %) |
| After | Hot Standby (0 %) |
Robinson with 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation | |
WEEKMONTHYEARENS 565852023-06-22T14:35:00022 June 2023 14:35:00
[Table view]10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Automatic Reactor Trip Occured During Protection System Testing ENS 542122019-08-11T12:40:00011 August 2019 12:40:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Automatic Reactor Trip Due to Turbine Trip ENS 537452018-11-19T05:00:00019 November 2018 05:00:00 10 CFR 50.72(b)(3)(iv)(A), System Actuation Emergency Diesel Generator Actuation Due to Low Voltage Signal ENS 526622017-04-04T01:55:0004 April 2017 01:55:00 10 CFR 50.72(b)(3)(iv)(A), System Actuation Automatic Actuation of Auxiliary Feedwater System During Surveillance Testing ENS 522902016-10-08T17:17:0008 October 2016 17:17:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(a)(1)(i), Emergency Class Declaration, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Unusual Event Declared Due to Loss of Offsite Power ENS 521982016-08-24T17:38:00024 August 2016 17:38:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Reactor Trip Due Automatic Turbine Trip from 100 Percent Power ENS 497082014-01-10T03:34:00010 January 2014 03:34:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Automatic Reactor Trip Due to Turbine Trip ENS 495062013-11-05T23:00:0005 November 2013 23:00:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Automatic Reactor Trip Due to Momentary Loss of 4 Kv Buses and Safety System Actuation ENS 495022013-11-05T05:41:0005 November 2013 05:41:00 10 CFR 50.72(b)(3)(iv)(A), System Actuation Automatic Actuation of the Auxiliary Feedwater System Due to Main Feed Pump Trip ENS 477812012-03-28T19:03:00028 March 2012 19:03:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Automatic Reactor Trip Due to Steam Generator High Water Level Condition ENS 472932011-09-26T15:45:00026 September 2011 15:45:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Automatic Reactor Trip Due to One Loop Low Flow Signal ENS 463132010-10-07T04:13:0007 October 2010 04:13:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Automatic Reactor Trip Due to a One Loop Reactor Coolant Low Flow ENS 462382010-09-09T18:37:0009 September 2010 18:37:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Reactor Trip Due to Overtemperature Delta-T Signal ENS 457992010-03-28T22:52:00028 March 2010 22:52:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(a)(1)(i), Emergency Class Declaration, 10 CFR 50.72(b)(3)(iv)(A), System Actuation, 10 CFR 50.72(b)(2)(iv)(A), System Actuation - ECCS Discharge Alert Declared Due to Fire Affecting Safety Related Equipment ENS 454832009-11-07T03:02:0007 November 2009 03:02:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Manual Reactor Trip Due to Feed Reg Valve Closure ENS 446602008-11-17T10:51:00017 November 2008 10:51:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Manual Reactor Scram Due to High Turbine Vibration ENS 433642007-05-15T15:16:00015 May 2007 15:16:00 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 Due to Differential Generator Protection ENS 429332006-10-25T06:48:00025 October 2006 06:48:00 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 a 100% Load Rejection 2023-06-22T14:35:00 | |