ENS 57718
ENS Event | |
|---|---|
15:45 May 19, 2025 | |
| Title | Manual Reactor Scram Due to Loss of Feedwater |
| Event Description | The following information was provided by the licensee via phone and email:
At 1045 CDT on May 19, 2025, with Unit 1 at 100 percent power, the reactor was manually tripped on lowering reactor water level caused by a loss of electrical power to the condensate and feedwater pumps. The trip was not complex with all systems responding as expected post-trip. Due to the reactor protection system actuation while critical, this event is being reported as a four-hour, non-emergency notification per 10 CFR 50.72(b)(2)(iv)(B) and an eight-hour, non-emergency notification per 10 CFR 50.72(b)(3)(iv)(A) for the group II isolation, group III isolation, and Unit I emergency diesel generator (EDG) automatic start. Operations responded using emergency operating procedures and stabilized the plant in hot shutdown. Decay heat is being removed through the automatic depressurization system and the residual heat removal system. Coincident with the transient on Unit 1, Unit 2 experienced a trip of a reactor feed pump resulting in a runback of the reactor recirculation pumps. Unit 2 is currently stable at 80 percent power. There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector and the Illinois Emergency Management Agency were notified. The following additional information was obtained from the licensee in accordance with Headquarters Operations Officers Report Guidance: On Unit 1, all control rods fully inserted on the scram and outboard main steam isolation valves closed on a loss of power. The initial bus trip was caused by control power perturbations due to a ground on the associated battery system.
Based on additional investigation, it has not been confirmed that the initial bus trip was caused by a ground on the associated battery system. The cause remains under investigation. Notified R3DO (Szwarc) |
| Where | |
|---|---|
Quad Cities  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:+-0.6 h-0.025 days <br />-0.00357 weeks <br />-8.2188e-4 months <br />) | |
| Opened: | Jason Cooper 15:09 May 19, 2025 |
| NRC Officer: | Robert A. Thompson |
| Last Updated: | May 20, 2025 |
| 57718 - NRC Website
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Unit 1 | |
|---|---|
| Reactor critical | Critical |
| Scram | Yes, Manual Scram |
| Before | (100 %) |
| After | (0 %) |
Quad Cities with 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation | |
WEEKMONTHYEARENS 577182025-05-19T15:45:00019 May 2025 15:45:00
[Table view]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 Loss of Feedwater ENS 571412024-05-23T16:46:00023 May 2024 16:46:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Automatic Scram Due to Turbine Trip Signal ENS 570582024-03-28T01:46:00028 March 2024 01:46:00 10 CFR 50.72(b)(3)(iv)(A), System Actuation Automatic Actuation of Reactor Protection System ENS 566762023-08-11T08:29:00011 August 2023 08:29:00 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 562102022-11-04T19:00:0004 November 2022 19:00:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation Manual Scram Due to Rising Water Level ENS 559752022-07-04T06:04:0004 July 2022 06:04:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation Reactor Manual Scram Due to Lowering Reactor Water Level ENS 551462021-03-20T01:30:00020 March 2021 01:30:00 10 CFR 50.72(b)(3)(iv)(A), System Actuation Automatic Actuation of Unit 1 Emergency Diesel Generator ENS 542392019-08-25T16:02:00025 August 2019 16:02:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Automatic Scram Due to Main Generator Ground Fault Relay ENS 536932018-10-24T05:00:00024 October 2018 05:00:00 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 1/2 Edg Auto Started and Lpci/Core Spray Inoperable Due to Loss of Safety Bus ENS 536262018-09-26T05:00:00026 September 2018 05:00:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Automatic Scram Due to Generator Output Breaker Trip ENS 509492015-04-03T02:33:0003 April 2015 02:33:00 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 Steam Leak ENS 499882014-04-02T18:40:0002 April 2014 18:40:00 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 Alert Declared Due to Fire in Unit 2 Turbine Building ENS 478472012-04-18T20:11:00018 April 2012 20:11:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Unit Two Automatic Reactor Scram on High Reactor Pressure ENS 469512011-06-13T10:10:00013 June 2011 10:10:00 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 Steam Leak in Turbine Building ENS 461842010-08-17T19:14:00017 August 2010 19:14:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Manual Reactor Scram Initiated Due to Recirculation Pump Trip ENS 461692010-08-12T08:58:00012 August 2010 08:58:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Unit 1 Reactor Automatic Scram Due to Turbine Trip ENS 431982007-02-28T07:20:00028 February 2007 07:20:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Unit 2 Reactor Manually Scrammed Due to Decreasing Condenser Vacuum ENS 425742006-05-14T14:57:00014 May 2006 14:57:00 10 CFR 50.72(b)(3)(iv)(A), System Actuation Emergency Diesel Generator Automatic Start ENS 423562006-02-22T07:22:00022 February 2006 07:22:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Automatic Reactor Scram Due to Valid Main Turbine Load Reject Signal ENS 417822005-06-17T16:20:00017 June 2005 16:20:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Automatic Reactor Scram Due to Ehc Malfunction ENS 406252004-03-30T13:40:00030 March 2004 13:40:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation Automatic Reactor Scram During Turbine Thrust Bearing Wear Detector Testing 2025-05-19T15:45:00 | |