ENS 50546
ENS Event | |
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08:03 Oct 17, 2014 | |
Title | Automatic Reactor Scram on High Average Power Range Monitor Flux |
Event Description | At 0303 [CDT], River Bend Nuclear Station sustained a reactor scram due to high Average Power Range Monitor [APRM] flux, suspected due to a malfunction of the Electrohydraulic Control System. Reactor recirculation pump 'B' tripped, reactor recirculation pump 'A' responded appropriately. All other systems responded appropriately except for loss of feed water due to low suction pressure trip from isolating the condensate demineralizers. Reactor water level did not get out of level band. Condensate demineralizers and feedwater were restored to service. Level 3 [isolation] was initiated due to scram. [One] system, Suppression Pool Cooling isolated accordingly due to level 3 signal. Currently the plant is in mode 3, hot shutdown. Plant will remain in mode 3 until investigation of scram is complete.
During the scram, all rods inserted into the core. No relief valves lifted as a result of the transient. All safety equipment is available although reactor core isolation cooling is functional but inoperable due to an earlier issue discovered during a surveillance test. The reactor is at normal pressure and temperature for Mode 3. The cause of the high APRM flux and the identified anomalies are under investigation. The licensee has notified the NRC Resident Inspector.
The licensee is updating the notification to include an 8 hour9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> notification for a specified system actuation due to the Level 3 isolation signal. Licensee is proceeding to cold shutdown to troubleshoot the EHC system. The licensee will notify the NRC Resident Inspector. Notified R4DO (Haire). |
Where | |
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River Bend Louisiana (NRC Region 4) | |
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:+-0.28 h-0.0117 days <br />-0.00167 weeks <br />-3.83544e-4 months <br />) | |
Opened: | Daniel Pipkin 07:46 Oct 17, 2014 |
NRC Officer: | Howie Crouch |
Last Updated: | Oct 17, 2014 |
50546 - NRC Website | |
Unit 1 | |
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Reactor critical | Critical |
Scram | A/R |
Before | Power Operation (100 %) |
After | Hot Shutdown (0 %) |
River Bend with 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation | |
WEEKMONTHYEARENS 568872023-12-13T07:02:00013 December 2023 07:02:00
[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 Scram ENS 568632023-11-18T05:55:00018 November 2023 05:55:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Manual Reactor Scram ENS 551692021-04-02T15:17:0002 April 2021 15:17:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation Automatic Reactor Scram Due to Turbine Trip ENS 551542021-03-25T14:18:00025 March 2021 14:18:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation Manual Reactor Trip Due to Lowering Condenser Vacuum ENS 548492020-08-21T14:18:00021 August 2020 14:18:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation Manual Reactor Scram ENS 540962019-06-01T04:45:0001 June 2019 04:45:00 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 Low Reactor Water Level ENS 537322018-11-10T05:00:00010 November 2018 05:00:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation Automatic Reactor Scram on High Reactor Pressure ENS 531922018-02-01T16:57:0001 February 2018 16:57:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation Manual Reactor Scram ENS 529152017-08-19T01:55:00019 August 2017 01:55:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation Automatic Scram While at 100 Percent Power ENS 528252017-06-24T01:18:00024 June 2017 01:18:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation Automatic Reactor Scram on Main Generator Trip ENS 526022017-03-10T13:14:00010 March 2017 13:14:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation Manual Reactor Scram Due to Closure of the Main Turbine Control Valves ENS 517012016-01-29T21:18:00029 January 2016 21:18:00 10 CFR 50.72(b)(3)(iv)(A), System Actuation Specified System Actuation After Loss of One Offsite Power Source ENS 516442016-01-09T08:37:0009 January 2016 08:37:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Automatic Reactor Scram on Main Steam Isolation Due to Electrical Fault ENS 515682015-11-27T10:31:00027 November 2015 10:31:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Automatic Reactor Scram Following Partial Loss of Offsite Power ENS 511122015-06-02T02:11:0002 June 2015 02:11:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Reactor Scram Due to Low Reactor Water Level ENS 508722015-03-08T03:40:0008 March 2015 03:40:00 10 CFR 50.72(b)(3)(iv)(A), System Actuation Specified System Actuation Due to Loss of One Reserve Station Service Offsite Power Source ENS 507042014-12-25T14:37:00025 December 2014 14:37:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Automatic Reactor Scram ENS 505462014-10-17T08:03:00017 October 2014 08:03:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Automatic Reactor Scram on High Average Power Range Monitor Flux ENS 479602012-05-24T18:48:00024 May 2012 18:48:00 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 Scram Due to a Loss of Feed as Result of a Loss of Switchgear ENS 479402012-05-21T19:52:00021 May 2012 19:52:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation Automatic Reactor Scram Resulting from a Low Condenser Vacuum-Turbine Trip ENS 475492011-12-23T12:10:00023 December 2011 12:10:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation Automatic Reactor Scram Due to a Turbine Trip ENS 453882009-09-29T16:27:00029 September 2009 16:27:00 10 CFR 50.72(b)(3)(iv)(A), System Actuation Loss of Water from Upper Refuel Pool ENS 453692009-09-20T22:47:00020 September 2009 22:47:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation Manual Scram Due to Reactor Recirc Pump Trip ENS 440342008-03-05T20:43:0005 March 2008 20:43:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation Automatic Scram Due to Apparent Malfunction in Turbine Control System ENS 437732007-11-07T09:06:0007 November 2007 09:06:00 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)(iv)(A), System Actuation - ECCS Discharge Reactor Scram as a Result of Loss of Normal Power 13.8 Kv Bus ENS 436682007-09-27T03:44:00027 September 2007 03:44:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation Automatic Reactor Scram During the Performance of Aprm Surveillance Testing ENS 433452007-05-04T17:56:0004 May 2007 17:56:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation Manual Reactor Scram Due to Loss of Cooling to Number 2 Main Transformer ENS 429212006-10-19T22:56:00019 October 2006 22:56:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident, 10 CFR 50.72(b)(3)(iv)(A), System Actuation, 10 CFR 50.72(b)(2)(iv)(A), System Actuation - ECCS Discharge Automatic Scram Following Spontaneous Feedwater Valve Closure ENS 425052006-04-15T21:15:00015 April 2006 21:15:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation Reactor Scram from 100% Power ENS 413392005-01-15T08:12:00015 January 2005 08:12:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation Manual Reactor Scram Due to Receiving a Main Generator Alarm ENS 412522004-12-10T19:17:00010 December 2004 19:17:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation Reactor Scram Due to Loss of Vital Instrument Bus ENS 411652004-11-01T22:44:0001 November 2004 22:44:00 10 CFR 50.72(b)(3)(iv)(A), System Actuation Emergency Diesel Generator Automatic Start ENS 411642004-11-01T03:56:0001 November 2004 03:56:00 10 CFR 50.72(b)(3)(iv)(A), System Actuation Plant Had Auto Start of the Division 1 Emergency Diesel Generator ENS 410822004-10-01T12:30:0001 October 2004 12:30:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(2)(iv)(A), System Actuation - ECCS Discharge Reactor Trip Due to Main Generator Load Rejection ENS 409572004-08-15T09:05:00015 August 2004 09:05:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Automatic Reactor Scram Following Partial Loss of Offsite Power ENS 401912003-09-23T03:43:00023 September 2003 03:43:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation Automatic Reactor Scram Received During Main Turbine Control Valve Testing 2023-12-13T07:02:00 | |