ENS 54197
ENS Event | |
|---|---|
07:26 Aug 3, 2019 | |
| Title | En Revision Imported Date 8/7/2019 |
| Event Description | EN Revision Text: AUTOMATIC REACTOR SCRAM ON LOW REACTOR WATER LEVEL
At 0226 [CDT], an automatic scram on low reactor water level occurred due to a trip of the 'B' Reactor Feed pump. All control rods fully inserted. Reactor water level 2 was reached and the High Pressure Core Spray system, Reactor Core Isolation Cooling system, Division 3 diesel generator, Standby Gas Treatment Systems 'A' and 'B' and all shutdown safety related service water pumps started as expected. Reactor Core Isolation Cooling and High Pressure Core Spray injected as expected. All level 2 containment isolation signals occurred as expected and all level 2 containment valves closed as expected. Reactor water level is currently being controlled in band by condensate. Reactor pressure is being maintained by main turbine Bypass Valves. This event is being reported under 10 CFR 50.72(b)(2)(iv)(A), for ECCS discharge to RCS; 10 CFR 50.72(b)(2)(iv)(B), for RPS actuation, and 10 CFR 50.72(b)(3)(iv)(A), for specified system actuation. The NRC Senior Resident Inspector has been notified. No safety relief valves lifted during the transient. The plant is in a normal shutdown electrical lineup with all safety equipment available. The licensee notified the Illinois Emergency Management Agency per their communications protocol.
Following automatic initiation of the High Pressure Core Spray (HPCS) System as described above, the HPCS System was manually secured following station procedures after verification that additional RPV [reactor pressure vessel] injection was no longer required. Securing HPCS injection in this manner prevents automatic restart of the system in the event of a subsequent low RPV level condition, rendering it inoperable. As the HPCS system is considered a single train safety system, this meets the reportability requirements of 10 CFR 50.72(b)(3)(v)(D). This reportable condition was identified following review of post-scram actions. The HPCS system has been restored to a Standby lineup. The licensee will be notifying the NRC Resident Inspector. Notified R3DO (Pelke).
Following the scram, the Primary Containment to Secondary Containment and the Drywell to Primary Containment differential pressure limits were exceeded. Technical Specification (TS) Limiting Condition for Operation (LCO) 3.6.1.4, Primary Containment Pressure, and 3.6.5.4, Drywell Pressure, Actions A.1, B.1, and B.2 were entered. Primary Containment to Secondary Containment differential pressure and Drywell to Primary Containment differential pressure were restored to within the LCO limits at 1505 on 8/3/19 and the associated TS Actions were exited. This event is reportable under 10 CFR 50.72(b)(3)(ii)(B) as an unanalyzed condition that could have prevented the fulfillment of the primary containment function due to being outside the initial conditions to ensure that drywell and containment pressures remain within design values during a loss of coolant accident. This event is also reportable under 10 CFR 50.72(b)(3)(v)(C) as an event or condition that could have prevented the fulfillment of the drywell and primary containment functions to control the release of radioactive material for the same reason. The licensee notified the NRC Resident Inspector. Notified R3DO (Pelke). |
| Where | |
|---|---|
Clinton  Illinois (NRC Region 3) | |
| Reporting | |
| 10 CFR 50.72(b)(2)(iv)(A), System Actuation - ECCS Discharge 10 CFR 50.72(b)(2)(iv)(B), RPS Actuation 10 CFR 50.72(b)(3)(iv)(A), System Actuation 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident | |
| Time - Person (Reporting Time:+-0.65 h-0.0271 days <br />-0.00387 weeks <br />-8.9037e-4 months <br />) | |
| Opened: | David Livingston 06:47 Aug 3, 2019 |
| NRC Officer: | Howie Crouch |
| Last Updated: | Aug 6, 2019 |
| 54197 - NRC Website | |
Unit 1 | |
|---|---|
| Reactor critical | Critical |
| Scram | A/R |
| Before | Power Operation (98 %) |
| After | Hot Shutdown (0 %) |
Clinton with 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 | |
WEEKMONTHYEARENS 563282023-02-01T05:43:0001 February 2023 05:43:00
[Table view]10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation Automatic Scram Due to Turbine Trip ENS 550022020-11-17T01:18:00017 November 2020 01:18:00 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident Both Trains of Main Control Room Ventilation and Air Conditioning Systems Inoperable ENS 544032019-11-21T18:25:00021 November 2019 18:25:00 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident ENS 542812019-09-16T13:17:00016 September 2019 13:17:00 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident Accident Mitigation ENS 541972019-08-03T07:26:0003 August 2019 07:26:00 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 En Revision Imported Date 8/7/2019 ENS 538242019-01-13T14:30:00013 January 2019 14:30:00 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident En Revision Imported Date 3/8/2019 ENS 536982018-10-28T05:00:00028 October 2018 05:00:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation Automatic Reactor Scram During a Reactor Shutdown ENS 536232018-09-26T05:00:00026 September 2018 05:00:00 10 CFR 50.72(b)(3)(iv)(A), System Actuation Undervoltage Condition Initiates an Automatic Start of the Diesel Generator ENS 534632018-06-20T05:00:00020 June 2018 05:00:00 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident High-Pressure Core Spray Inoperable ENS 534092018-05-17T20:03:00017 May 2018 20:03:00 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident Emergency Diesel Generators Inoperable ENS 531102017-12-09T19:48:0009 December 2017 19:48:00 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)(ii)(B), Unanalyzed Condition, 10 CFR 50.72(b)(3)(v)(C), Loss of Safety Function - Release of Radioactive Material Manual Reactor Scram Due to Loss of Division 1 Ac Power to Numerous Components ENS 528062017-06-15T14:58:00015 June 2017 14:58:00 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident High Pressure Core Spray Declared Inoperable ENS 528002017-06-11T03:56:00011 June 2017 03:56:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation Manual Reactor Scram Due to Loss of Feedwater Heating ENS 527772017-05-31T01:38:00031 May 2017 01:38:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation Automatic Reactor Scram ENS 516692016-01-20T19:11:00020 January 2016 19:11:00 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident, 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Primary-Secondary Containment Pressure Differential Exceeded Due to Ccp Exhaust Fan Trip ENS 504632014-09-17T00:05:00017 September 2014 00:05:00 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident Loss of Division 3 of Shutdown Service Water Requires Hpcs to Be Declared Inoperable ENS 499582014-03-26T00:42:00026 March 2014 00:42:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation Manual Reactor Scram Due to Loss of Condenser Vacuum ENS 496322013-12-13T23:57:00013 December 2013 23:57:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation Manual Reactor Trip During Feed Pump Swap ENS 496172013-12-09T02:27:0009 December 2013 02:27:00 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)(v)(C), Loss of Safety Function - Release of Radioactive Material Manual Scram Due to Loss of Division 1 480 Vac Power Causing Loss of Instrument Air to Containment and Scram Air Header ENS 492862013-08-15T14:15:00015 August 2013 14:15:00 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident Diesel Generator Declared Inoperable Due to Damper Failing to Open ENS 489742013-04-26T13:55:00026 April 2013 13:55:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation Manual Reactor Scram Due to Rapidly Decreasing Level in the Ehc Oil Reservoir ENS 488122013-03-07T13:56:0007 March 2013 13:56:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation Automatic Reactor Scram on Generator Trip/Turbine Trip ENS 487652013-02-18T09:18:00018 February 2013 09:18:00 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident High Pressure Core Spray Declared Inoperable ENS 485332012-11-24T02:08:00024 November 2012 02:08:00 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident, 10 CFR 50.72(b)(3)(v)(C), Loss of Safety Function - Release of Radioactive Material Inadvertent Loss of Instrument Air ENS 475332011-12-18T15:30:00018 December 2011 15:30:00 10 CFR 50.72(b)(3)(v)(B), Loss of Safety Function - Remove Residual Heat, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Loss of Rhr Cooling Due to Incorrect Reactor Water Level Indication ENS 474892011-11-29T23:28:00029 November 2011 23:28:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation Unit Experienced an Automatic Reactor Scram During a Planned Shutdown ENS 454332009-10-15T10:37:00015 October 2009 10:37:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation Manual Reactor Scram Due to Reactor Recirculation Pump Trip ENS 451812009-07-02T19:15:0002 July 2009 19:15:00 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident Hpcs Inoperable Due to Logic Card Failure ENS 439762008-02-11T04:07:00011 February 2008 04:07:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation Manual Reactor Scram Due to Increasing Reactor Vessel Level ENS 434162007-06-11T01:03:00011 June 2007 01:03:00 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident High Pressure Core Spray Declared Inoperable Due to Failed Inverter ENS 429782006-11-09T12:44:0009 November 2006 12:44:00 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident High Pressure Core Spray System Valve Inadvertently De-Energized ENS 429292006-10-24T06:42:00024 October 2006 06:42:00 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident High Pressure Core Spray (Hpcs) Declared Inoperable for Approx. 3.4 Hours ENS 428072006-08-27T22:05:00027 August 2006 22:05:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation Reactor Trip Due to Reactor High Water Level ENS 427822006-08-17T15:44:00017 August 2006 15:44:00 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident Main Turbine Bypass Valves Inoperable ENS 424302006-03-20T10:53:00020 March 2006 10:53:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation Main Turbine Trip Caused Reactor Scram ENS 409832004-08-24T14:17:00024 August 2004 14:17:00 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident High Pressure Core Spray (Hpcs) Declared Inoperable ENS 408692004-07-14T05:45:00014 July 2004 05:45:00 10 CFR 50.72(b)(3)(iv)(A), System Actuation Rps and Containment Isolation Actuation Due to Low Rpv Level ENS 408682004-07-13T21:10:00013 July 2004 21:10:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation Automatic Reactor Scram Due to Possible Adverse Weather ENS 406522004-04-06T19:00:0006 April 2004 19:00:00 10 CFR 50.72(b)(3)(v)(A), Loss of Safety Function - Shutdown the Reactor, 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident Air Valve Misalignment Reduces Standby Liquid Control Capability ENS 406042004-03-23T01:31:00023 March 2004 01:31:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation Reactor Scram from 93% Power Due to Generator Trip ENS 403682003-12-02T22:58:0002 December 2003 22:58:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Manual Scram Due to Low Reactor Water Feed Pump Suction Pressure 2023-02-01T05:43:00 | |