05000335/LER-2025-001-01, Safety Injection Tank Above Technical Specifications Limit
| ML25099A035 | |
| Person / Time | |
|---|---|
| Site: | Saint Lucie  |
| Issue date: | 04/08/2025 |
| From: | Mack K Florida Power & Light Co |
| To: | Office of Nuclear Reactor Regulation, Document Control Desk |
| References | |
| L-2025-067 LER 2025-001-01 | |
| Download: ML25099A035 (1) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications |
| 3352025001R01 - NRC Website | |
text
l=PL U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555 Re:
St. Lucie Unit 1 Docket No. 50-335 Renewed Facility Operating License No. DPR-67 Reportable Event: 2025-01-01 Date of Event: January 27, 2025 Safety Injection Tank Above Technical Specifications Limit April 8, 2025 L-2025-067 10CFR50.73 The attached Licensee Event Report, 2025-01-01, is being submitted pursuant to the requirements of 10 CFR 50.73 to provide notification of the subject event.
Should you have any questions regarding this submission, please contact Maribel Valdez, Fleet Licensing Manager, at 561-904-5164.
This letter contains no new or modified regulatory commitments.
Sincerely, Kenneth A. Mack Director, Licensing and Regulatory Compliance Florida Power & Light Company Attachment cc:
USNRC Regional Administrator, Region II USNRC Project Manager, St. Lucie Power Nuclear Plant USNRC Senior Resident Inspector, St. Lucie Power Nuclear Plant Mr. Clark Eldredge, Florida Department of Health Florida Power & Light Company 6501 S. Ocean Drive, Jensen Beach, FL 34957
Abstract
On January 27, 2025, at Unit 1, 1A1 Safety Injection Tank (SIT) indicated level became erratic, rendering 1A1 SIT inoperable. Instrumentation and Control (l&C) technicians replaced a circuit card for the level transmitter. After I
calibration, the 1A1 SIT level indicated 100.8% which is above the Technical Specification Surveillance Requirement Limit (1170 ft 3
) for SIT volume. 1A 1 SIT water volume was then reduced from 100.8% to 94.2% indicated level which is within the Technical Specification (TS) volume limit of 1090 - 1170ft'. As level was being lowered, the High-High level alarm cleared and 1 A 1 SIT was declared operable. The 1 A 1 SIT level transmitter had a failed circuit card in the I level transmitter, causing inaccurate indication on the A-train Level Indication Alarm (LIA-3321 ). There were no systems, structures, or components that were inoperable at the start of the event that contributed to the event. This event is being reported pursuant of 10 CFR 50. 73(a)(2)(i)(B), Operation or Condition Prohibited by TS.
Description of Event
Estimated burden per response to comply with this mandatory collection request: 80 hours9.259259e-4 days <br />0.0222 hours <br />1.322751e-4 weeks <br />3.044e-5 months <br />. Reported lessons learned are incorporated into the licensing process and fed back to industry. Send comments regarding burden estimate to the FOIA, Library, and Information Collections Branch (T-6 A10M), U.S.
Nuclear Regulatory Commission, Washington, DC 20555-0001,
or by email to lnfocollects.Resource@nrc.gov, and the 0MB reviewer at: 0MB Office of Information and Regulatory Affairs, (3150-0104), Attn: Desk Officer for the Nuclear Regulatory Commission, 725 17th Street NW, Washington, DC 20503. The NRC may not conduct or sponsor, and a person is not required to respond to, a collection of information unless the document requesting or requiring the collection displays a currently valid 0MB ccntrol number.
- 2. DOCKET NUMBER
- 3. LER NUMBER I
335 D
NUMBER NO.
I YEAR SEQUENTIAL REV
~
01 1-0 On January 27, 2025, at Unit 1, 1 A 1 SIT indicated level became erratic, rendering 1 A 1 SIT inoperable. l&C technicians replaced a circuit card for the level transmitter. After calibration, the 1A 1 SIT level indicated 100.8% which is above the Technical Specification Surveillance Requirement Limit (1170 ft3) for SIT volume.
1A1 SIT water volume was then reduced from 100.8% to 94.2% indicated level which is within the TS volume limit of 1090 - 1170 ft3. As level was being lowered, the High-High level alarm cleared and 1 A 1 SIT was declared operable. Prior to the event on January 8, 2025, a High-High level alarm was received while filling 1A 1 SIT. The indicated level, as read from LIA-3321, appeared within the normal operating band. However, complications arose due to the Level Transmitter faulting, which was the result of a problem with the L T-3321 circuit card. Therefore, the High-High level alarm remained locked in until the event occurred on January 27.
Cause of Event
The 1A 1 SIT L T-3321 circuit card failed causing inaccurate SIT level indication.
Safety Significance
This event resulted in an entry into Technical Specification Action Statement (TSAS) 3.5.1, Action B (24-hour shutdown) and an NRC reportable event.
The Licensee Event Report is being reported pursuant of 10 CFR 50.73 (a)(2)(i)(B), Operation or Condition Prohibited by TS.
This event did not result in a Safety System Functional Failure.
Corrective Actions
Corrected by the replacement and calibration of the circuit card.
Similar Events
A review of events over the past 5 years did not identify any similar events with the same cause as this event. Page 2
of 2
-=--