ML26029A377
| ML26029A377 | |
| Person / Time | |
|---|---|
| Site: | Braidwood  |
| Issue date: | 01/29/2026 |
| From: | Constellation Energy Generation |
| To: | Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML26029A374 | List: |
| References | |
| BW260007 | |
| Download: ML26029A377 (0) | |
Text
Attachment January 29, 2026 Page 1 of 2 Braidwood Station Unit 1 Post Accident Monitoring Report This report is being submitted for Braidwood Station Unit 1 in accordance with Technical Specifications (TS) 5.6.7, Post Accident Monitoring Report. 1 L-PC007 B Train Containment Floor Water Level was declared inoperable and TS 3.3.3 Condition B was entered at 1211 on December 17, 2025. Condition B requires the inoperable channel to be restored to operable within 30 days. Constellation Energy Generation, LLC has determined that this channel could not be restored within 30 days, due to parts unavailability to perform replacement of the level transmitter.
TS 3.3.3 Condition B requires initiation of action in accordance with TS 5.6.7 to submit a written report within 14 days outlining the preplanned alternate method of monitoring, the cause of the inoperability, and the plans and schedule for restoring the instrumentation channel to operable status.
Description of Issue:
On December 17, 2025 during performance of Instrument Maintenance Department (IMO) Work Order (WO): 5518115-01 (1L-PC007 CAL OF CNMT WTR LVL LOOP); 1LT-PC007 was found out of tolerance. IMO attempted to adjust the transmitter back into tolerance with no success. The replacement transmitter from stores required a hydrostatic test due to a Part 21 report and was sent out for testing. The test lab determined that the transmitter did not have the required bellows attached and capillary tube prefilled. The second replacement transmitter from stores also had same issue and could also not be installed. As a result, no parts were available for replacement within the 30-day window.
Per TS Bases 3.3.3, Containment Floor Water Level is provided for verification and long-term surveillance of Reactor Coolant System integrity. It is also used to determine accident diagnosis, when cold leg recirculation can be implemented and whether to terminate Safety Injection following a Loss of Coolant Accident, if still in progress.
Preplanned Alternate Method of Monitoring 1A Train Containment Floor Water Level (1 L-PC006) offers redundant monitoring capability and is available as an alternate method of monitoring.
Cause of inoperability Per TS Bases 3.3.3, 1 L-PC007 (CNMT WTR LVL LOOP) B Train Containment Floor Water Level in considered operable when the channel is calibrated in accordance with the Surveillance Frequency Control Program.
1 L-PC007 (CNMT WTR LVL LOOP) B Train Containment Floor Water Level was declared inoperable due to the loop being found out of tolerance and being unable to adjust the transmitter back into tolerance. Investigation determined this was an original plant component that failed as a result of typical aging mechanisms.
Attachment January 29, 2026 Page 2 of 2 Plans for Restoration A WO has been prepared for maintenance to replace the inoperable 1 L T-PC007. Based on availability of parts, WO is scheduled to be completed in February 2026.