ENS Event | |
|---|---|
22:00 Dec 29, 2025 | |
| Title | Degraded Condition |
| Event Description | The following information was provided by the licensee via phone and email:
At 1600 CST on 12/29/2025, it was determined that a through-wall leak identified on a three-quarter inch vent valve off of the bonnet of the Unit 1 'B' reactor recirculation flow control valve qualifies as pressure boundary leakage resulting in a degraded reactor coolant system pressure boundary. Leakage repair will be completed prior to plant startup from the current outage. Therefore, this event is being reported as an eight-hour, non-emergency notification per 10 CFR 50.72(b)(3)(ii)(A). There was no impact on the health and safety of the public or plant personnel.? The NRC Resident Inspector has been notified. The State of Illinois will be notified. The following additional information was obtained from the licensee in accordance with Headquarters Operations Officers Report Guidance: This event is related to EN 58100. |
| Where | |
|---|---|
LaSalle  Illinois (NRC Region 3) | |
| Reporting | |
| 10 CFR 50.72(b)(3)(ii)(A), Seriously Degraded | |
| Time - Person (Reporting Time:+-0.87 h-0.0363 days <br />-0.00518 weeks <br />-0.00119 months <br />) | |
| Opened: | Brock Pollmann 21:08 Dec 29, 2025 |
| NRC Officer: | Robert A. Thompson |
| Last Updated: | Dec 29, 2025 |
| 58102 - NRC Website
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Unit 1 | |
|---|---|
| Reactor critical | Not Critical |
| Scram | No |
| Before | Cold Shutdown (0 %) |
| After | Cold Shutdown (0 %) |
WEEKMONTHYEARENS 581022025-12-29T22:00:00029 December 2025 22:00:00
[Table view]10 CFR 50.72(b)(3)(ii)(A), Seriously Degraded Degraded Condition ENS 532762018-03-22T08:00:00022 March 2018 08:00:00 10 CFR 50.72(b)(2)(i), Tech Spec Required Shutdown, 10 CFR 50.72(b)(3)(ii)(A), Seriously Degraded Technical Specification Required Shutdown Due to Pressure Boundary Leakage ENS 513002015-08-07T18:40:0007 August 2015 18:40:00 10 CFR 50.72(b)(3)(ii)(A), Seriously Degraded Degraded Condition Due to Pressure Boundary Leakage on Vent Line Welded Joint ENS 489772013-04-28T02:24:00028 April 2013 02:24:00 10 CFR 50.72(b)(2)(i), Tech Spec Required Shutdown, 10 CFR 50.72(b)(3)(ii)(A), Seriously Degraded Technical Specification Required Plant Shutdown ENS 489432013-04-18T19:00:00018 April 2013 19:00:00 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)(A), Seriously Degraded Pin Holes Leaks Identified in High Pressure Core Spray System ENS 466052011-02-10T00:04:00010 February 2011 00:04:00 10 CFR 50.72(b)(2)(i), Tech Spec Required Shutdown, 10 CFR 50.72(b)(3)(ii)(A), Seriously Degraded Pressure Boundary Leakage ENS 414872005-03-13T00:30:00013 March 2005 00:30:00 10 CFR 50.72(b)(3)(ii)(A), Seriously Degraded Pinhole Leak in Instrument Drain Line Off Main Steam System 2025-12-29T22:00:00 | |