ENS 54289
ENS Event | |
|---|---|
16:06 Sep 23, 2019 | |
| Title | Automatic Reactor Trip Due to Lowering Steam Generator Levels |
| Event Description | At 1106 CDT Braidwood Unit 1 experienced an automatic reactor trip due to lowering steam generator water levels following closure of the 1B steam generator feed water regulating valve.
The cause of the 1B steam generator feedwater regulating valve failing closed is unknown at this time and is under investigation. Both trains of auxiliary feedwater started automatically following the reactor trip to maintain steam generator water levels. All systems responded as expected with the exception of intermediate range nuclear instrument N-36 which was identified as being undercompensated following the reactor trip. Both source range nuclear instruments were manually energized in accordance with station procedures. Steam generator power operated relief valves lifted momentarily and reseated as designed in response to the secondary transient due to the reactor trip. The main steam dump valves are in service to the main condenser to provide heat sink cooling. The plant is being maintained at normal operating pressure and temperature. AC power is being provided by offsite power with the diesel generators in stand by and all safety systems available. There is no impact to Unit 2. This report is being made per 10 CFR 50.72(b)(2)(iv)(B) for a RPS actuation, 4 hour4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> notification, and per 10 CFR 50.72(b)(3)(iv)(A) for an automatic actuation of the auxiliary feedwater system, 8 hour9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> notification. The NRC Resident Inspector has been informed. |
| Where | |
|---|---|
Braidwood  Illinois (NRC Region 3) | |
| Reporting | |
| 10 CFR 50.72(b)(2)(iv)(B), RPS Actuation 10 CFR 50.72(b)(3)(iv)(A), System Actuation | |
| Time - Person (Reporting Time:+-1.85 h-0.0771 days <br />-0.011 weeks <br />-0.00253 months <br />) | |
| Opened: | Richard Rowe 14:15 Sep 23, 2019 |
| NRC Officer: | Caty Nolan |
| Last Updated: | Sep 23, 2019 |
| 54289 - NRC Website | |
Unit 1 | |
|---|---|
| Reactor critical | Critical |
| Scram | A/R |
| Before | Power Operation (100 %) |
| After | Hot Standby (0 %) |
Braidwood with 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation | |
WEEKMONTHYEARENS 553202021-06-21T05:51:00021 June 2021 05:51:00
[Table view]10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation Reactor Trip on Generator Lockout Relay Trip ENS 542892019-09-23T16:06:00023 September 2019 16:06:00 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 Lowering Steam Generator Levels ENS 534432018-06-04T14:20:0004 June 2018 14:20:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Manual Reactor Trip on Lowering Steam Generator Water Level ENS 533712018-04-30T16:24:00030 April 2018 16:24:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Automatic Reactor Trip Following Turbine Trip ENS 533582018-04-22T21:46:00022 April 2018 21:46:00 10 CFR 50.72(b)(3)(iv)(A), System Actuation Undervoltage Actuation of the Engineered Safety Feature Bus ENS 533472018-04-19T16:52:00019 April 2018 16:52:00 10 CFR 50.72(b)(3)(iv)(A), System Actuation Undervoltage Actuation of the Engineered Safety Feature Bus ENS 514502015-10-05T06:05:0005 October 2015 06:05:00 10 CFR 50.72(b)(3)(iv)(A), System Actuation Specified System Actuations ENS 462622010-09-20T22:04:00020 September 2010 22:04:00 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 461782010-08-16T07:06:00016 August 2010 07:06:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Automatic Reactor Trips at Both Units ENS 452382009-07-31T02:08:00031 July 2009 02:08:00 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 a Loss of Offsite Power for Greater than 15 Minutes ENS 450172009-04-24T16:41:00024 April 2009 16:41:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Automatic Reactor Trip During Instrument Calibration ENS 447432008-12-27T20:18:00027 December 2008 20:18:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Automatic Reactor Trip as a Result of a Generator Trip ENS 435902007-08-23T20:30:00023 August 2007 20:30:00 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)(3)(xiii), Loss of Emergency Preparedness Manual Reactor Trip Because of Lowering Condenser Vacuum ENS 434492007-06-27T14:21:00027 June 2007 14:21:00 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 Off-Site Power Fluctuation ENS 415352005-03-28T18:46:00028 March 2005 18:46:00 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 Generator Protection Circuitry ENS 412802004-12-22T19:07:00022 December 2004 19:07:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Rps Actuation Due to Steam Generator Low Level Signal ENS 403702003-12-03T09:36:0003 December 2003 09:36:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Plant Had an Auto Reactor Trip from 100% Power Due to Steam Generator Low Level ENS 402982003-11-05T03:32:0005 November 2003 03:32:00 10 CFR 50.72(b)(3)(iv)(A), System Actuation Braidwood 2 Afw Support System Actuation During Outage 2021-06-21T05:51:00 | |