ENS 57344
ENS Event | |
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11:46 Sep 27, 2024 | |
Title | |
Event Description | The following information was provided by the licensee via phone and email:
At 0748 EDT on 9/27/24, Catawba Unit 2 was manually tripped due to loss of condenser vacuum. The Unit 2 auxiliary feedwater (AFW) system started automatically as expected. Decay heat is being removed by the steam generators and discharging to the condenser. Due to the Unit 2 reactor protection system actuation while critical, this event is being reported as a four-hour, nonemergency notification per 10 CFR 50.72(b)(2)(iv)(B). The automatic start of the Unit 2 AFW system is being reported as an eight-hour, nonemergency notification per 10 CFR 50.72(b)(3)(iv)(A). On Unit 1, it was determined that at 0746, all trains of the Unit 1 AFW were inoperable when the Unit 1 hotwell temperature exceeded the operability limit for the AFW system. Therefore, this condition is being reported as an eight-hour, nonemergency notification per 10 CFR 50.72(b)(3)(v). The affected safety function was restored on 9/27/24 at 0851 EDT when the Unit 1 hotwell temperature returned below the operability limit for the AFW system. There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified. The following additional information was obtained from the licensee in accordance with Headquarters Operations Officers Report Guidance: The loss of vacuum for both Unit 1 and Unit 2 was due to loss of power to cooling tower fans. The suspected cause of loss of cooling tower fans was due to water intrusion due to Hurricane Helene. |
Where | |
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Catawba 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 10 CFR 50.72(b)(3)(v)(B), Loss of Safety Function - Remove Residual Heat | |
Time - Person (Reporting Time:+-0.35 h-0.0146 days <br />-0.00208 weeks <br />-4.7943e-4 months <br />) | |
Opened: | Tom Chandler 11:25 Sep 27, 2024 |
NRC Officer: | Adam Koziol |
Last Updated: | Sep 27, 2024 |
57344 - NRC Website
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Unit 1 | |
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Reactor critical | Critical |
Scram | No |
Before | Power Operation (95 %) |
After | Power Operation (33 %) |
Unit 2 | |
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Reactor critical | Critical |
Scram | Yes, Manual Scram |
Before | Power Operation (100 %) |
After | Hot Standby (0 %) |
Catawba with 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)(v)(B), Loss of Safety Function - Remove Residual Heat | |
WEEKMONTHYEARENS 573442024-09-27T11:46:00027 September 2024 11:46:00
[Table view]10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 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 Manual Reactor Trip Due to Loss of Condenser Vacuum ENS 570262024-03-13T01:11:00013 March 2024 01:11:00 10 CFR 50.72(b)(3)(iv)(A), System Actuation Loss of Power to Containment Radiation Monitors ENS 561772022-10-24T12:57:00024 October 2022 12:57:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Manual Reactor Trip and Auxiliary Feedwater System Actuation ENS 558562022-04-23T06:24:00023 April 2022 06:24:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Manual Reactor Trip During Control Rod Testing ENS 555492021-10-27T18:29:00027 October 2021 18:29:00 10 CFR 50.72(b)(3)(iv)(A), System Actuation Automatic Actuation of the 1B EDG Load Sequencer on Bus Undervoltage Condition ENS 552292021-05-01T11:55:0001 May 2021 11:55:00 10 CFR 50.72(b)(3)(iv)(A), System Actuation Automatic Reactor Trip and Actuation of the Auxiliary Feedwater System ENS 548882020-09-08T13:25:0008 September 2020 13:25:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation Automatic Reactor Trip on Over Power Delta Temperature ENS 545232020-02-12T23:00:00012 February 2020 23:00:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation Automatic Reactor Scram Due to Main Turbine Trip ENS 543072019-10-02T08:15:0002 October 2019 08:15:00 10 CFR 50.72(b)(3)(iv)(A), System Actuation Actuation of Containment Spray System ENS 542862019-07-06T05:56:0006 July 2019 05:56:00 10 CFR 50.72(b)(3)(v)(A), Loss of Safety Function - Shutdown the Reactor, 10 CFR 50.72(b)(3)(v)(B), Loss of Safety Function - Remove Residual Heat, 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident Both Trains of Component Cooling Water Determined Inoperable ENS 532712018-03-19T07:29:00019 March 2018 07:29:00 10 CFR 50.72(b)(3)(iv)(A), System Actuation Unplanned Actuation of Auxiliary Feedwater System During Maintenance ENS 491612013-06-30T21:20:00030 June 2013 21:20:00 10 CFR 50.72(b)(3)(v)(B), Loss of Safety Function - Remove Residual Heat Auxiliary Feedwater System Declared Inoperable Due to High Hotwell Temperatures ENS 467802011-04-23T13:21:00023 April 2011 13:21:00 10 CFR 50.72(b)(3)(iv)(A), System Actuation Valid Auxiliary Feedwater Pump Start While Cooling Down Reactor ENS 435972007-08-25T14:58:00025 August 2007 14:58:00 10 CFR 50.72(b)(3)(iv)(A), System Actuation Autostart of All Emergency Diesel Generators Due to a Grid Disturbance ENS 412462004-12-06T02:35:0006 December 2004 02:35:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Automatic Turbine Trip/Reactor Trip Due to Moisture Separator Reheater (Msr) High Level Trip Signal. ENS 411542004-10-28T04:52:00028 October 2004 04:52:00 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 Shutdown Bank Dropped Into Core ENS 405382004-02-22T22:30:00022 February 2004 22:30:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Unit 1 Manually Tripped After the "B" Sg Feedwater Isolation Valve Failed Closed ENS 403592003-11-28T03:55:00028 November 2003 03:55:00 10 CFR 50.72(b)(3)(v)(B), Loss of Safety Function - Remove Residual Heat, 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 Component Cooling System Surge Tank Supports May Fail During a Seismic Event ENS 401142003-08-29T06:03:00029 August 2003 06:03:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Catawba Unit 1 Automatic Reactor Trip Due to Reactor Protection System Actuation 2024-09-27T11:46:00 | |