ENS Event | |
|---|---|
05:00 Sep 26, 2018 | |
| Title | Undervoltage Condition Initiates an Automatic Start of the Diesel Generator |
| Event Description | At 0946 CDT on 9/26/2018, a disruption in power to the offsite 138 kV line and the subsequent trip of the Emergency Reserve Auxiliary Transformer (ERAT) Static VAR Compensator (SVC) resulted in a degraded voltage signal on the Division 1- 4.16 kV safety bus. The degraded voltage signal resulted in a trip of the ERAT feed to the bus, blocking closure of the 345 kV Reserve Auxiliary Transformer (RAT) feed to the bus and auto start of the Division 1 Emergency Diesel Generator (EDG). The Division 1 EDG successfully started and re-energized the Division 1- 4.16 kV bus as designed. The unit is stable with the Division 1 EDG carrying the Division 1- 4.16 kV bus.
The Ameren Transmission System Operator in St. Louis, MO informed the station that they had received a report that a 138 kV to 13.8 kV transformer at Clinton Route 54 substation was on fire and the South feed to the Tabor substation cycled as a result of this fault. The NRC Resident Inspector and Illinois Emergency Management Agency Resident Inspector have been notified. |
| Where | |
|---|---|
Clinton  Illinois (NRC Region 3) | |
| Reporting | |
| 10 CFR 50.72(b)(3)(iv)(A), System Actuation | |
| Time - Person (Reporting Time:+10.17 h0.424 days <br />0.0605 weeks <br />0.0139 months <br />) | |
| Opened: | Patrick Selzer 15:10 Sep 26, 2018 |
| NRC Officer: | Vince Klco |
| Last Updated: | Sep 26, 2018 |
| 53623 - NRC Website
Loading map... | |
Unit 1 | |
|---|---|
| Reactor critical | Critical |
| Scram | No |
| Before | Power Operation (98 %) |
| After | Power Operation (98 %) |
WEEKMONTHYEARENS 580402025-11-14T19:51:00014 November 2025 19:51:00
[Table view]10 CFR 50.72(b)(3)(iv)(A), System Actuation Automatic Actuation of Emergency Diesel Generators 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 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 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 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 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 2025-11-14T19:51:00 | |