ENS Event | |
|---|---|
04:17 Mar 1, 2019 | |
| Title | Specified System Actuation - Trip of Safety Related Bus |
| Event Description | On February 28, 2019, at 2217 CST, LaSalle Unit 2 experienced a trip of the 241Y Safety Related Bus during surveillance testing resulting in a valid undervoltage actuation signal to the Common Emergency Diesel Generator ('O' EDG), causing it to start and load to Bus 241Y. The purpose of the surveillance testing was to demonstrate the operability of the breakers necessary to provide the second off site source to Unit 2. This event is reportable in accordance with 10 CFR 50.72(b)(3)(iv)(A), as an event that results in a valid actuation of the emergency AC electrical power system. In addition to the 241Y bus trip and 'O' EDG actuation signal, the following plant responses occurred as designed due to the momentary loss of this AC Bus: "A" RPS de-energized due to the loss of the 2A Reactor Protection System Motor-Generator Set, and the running Unit 2 Fuel Pool Cooling pump tripped. The Non-Safety Related Bus 241X de-energized resulting in a trip of the Unit 2 Station Air Compressor. All systems have been restored and troubleshooting is currently in progress. Unit 1 remained in MODE 1 during this event.
The NRC Senior Resident Inspector has been notified." |
| Where | |
|---|---|
Lasalle  Illinois (NRC Region 3) | |
| Reporting | |
| 10 CFR 50.72(b)(3)(iv)(A), System Actuation | |
| Time - Person (Reporting Time:+-0.23 h-0.00958 days <br />-0.00137 weeks <br />-3.15054e-4 months <br />) | |
| Opened: | Wayne Clayton 04:03 Mar 1, 2019 |
| NRC Officer: | Joanna Bridge |
| Last Updated: | Mar 1, 2019 |
| 53903 - NRC Website | |
WEEKMONTHYEARENS 563892023-03-04T15:10:0004 March 2023 15:10:00
[Table view]10 CFR 50.72(b)(3)(iv)(A), System Actuation Automatic Actuation of Reactor Protection System (RPS) ENS 539032019-03-01T04:17:0001 March 2019 04:17:00 10 CFR 50.72(b)(3)(iv)(A), System Actuation Specified System Actuation - Trip of Safety Related Bus ENS 503462014-08-05T22:34:0005 August 2014 22:34:00 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 489392013-04-17T20:11:00017 April 2013 20:11:00 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, 10 CFR 50.72(b)(2)(iv)(A), System Actuation - ECCS Discharge Notification of Unusual Event Declared Due to Loss of Offsite Power from a Lightning Strike ENS 423482006-02-20T06:23:00020 February 2006 06:23:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition, 10 CFR 50.72(a)(1)(i), Emergency Class Declaration, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Site Area Emergency - Reactor Scram ENS 417872005-06-22T04:40:00022 June 2005 04:40:00 10 CFR 50.72(b)(3)(iv)(A), System Actuation Multiple Specified Systems Actuations Due to Loss of Ac Safety Related Buses ENS 404952004-02-02T04:34:0002 February 2004 04:34:00 10 CFR 50.72(b)(3)(iv)(A), System Actuation One Half Scram Signal Due to the Loss of the "B" Reactor Protection System Bus. 2023-03-04T15:10:00 | |