05000250/LER-2024-003-01, Condition Prohibited by Technical Specifications
| ML25065A080 | |
| Person / Time | |
|---|---|
| Site: | Turkey Point  |
| Issue date: | 03/06/2025 |
| From: | Mack K Florida Power & Light Co |
| To: | Office of Nuclear Reactor Regulation, Document Control Desk |
| References | |
| L-2025-044 LER 2024-003-01 | |
| Download: ML25065A080 (1) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications |
| 2502024003R01 - NRC Website | |
text
FPL U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555 Re:
Turkey Point Unit 3 Docket No. 50-250 Reportable Event: 2024-03-01 Date of Event: November 17, 2024 Condition Prohibited by Technical Specifications March 6, 2025 L-2025-044 10 CFR 50.73 The attached Licensee Event Report 2024-03-01 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.
Respectfu I ly, Kenneth A. Mack Director, Licensing and Regulatory Compliance Florida Power & Light Company Attachment cc:
Turkey Point NRC Senior Resident Inspector Turkey Point Station NRC Program Manager Florida Power & Light Company 9760 SW 344th Street, Homestead, FL 33035
Abstract
On November 17, 2024, at 1145 EST, while in Mode 1 with Unit 3 at 48 percent power following a planned refueling outage, Nuclear Instrument (Nl)(System Code JD) channel N-3-43 Upper Detector was observed to be reading lower than expected following a calibration. Subsequent troubleshooting determined the instrument was inoperable from November 14 to 19, 2024 due to water intrusion into the instruments signal cable. Technical Specifications (TS) Section 3.3.1, Reactor Trip System (RTS)
Instrumentation, Action 3.3.1.E, One Power Range Neutron Flux Low channel inoperable, requires an inoperable channel to be placed in Trip within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />. If the channel is not placed in Trip within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />, TS Action 3.3.1.T requires the unit to be in Mode 3 within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />. These actions were not completed within the TS completion times, thus creating a Condition Prohibited by TS. 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 S0.73(a)(2)(i)(B), Condition Prohibited by TS.
Description of Event
- 2. DOCKET NUMBER
- 3. LER NUMBER I
00250 D
NUMBER NO.
I YEAR SEQUENTIAL REV
~-I 03 1-0 On November 17, 2024, at 1145 EST, while in Mode 1 with Unit 3 at 48 percent power following a planned refueling outage, Nuclear Instrument (Nl)(System Code JD) channel N-3-43 Upper Detector was observed to be reading lower than expected following a calibration. Subsequent troubleshooting determined the instrument was inoperable from November 14 to 19, 2024 due to water intrusion into the instruments signal cable. Technical Specifications (TS) Section 3.3.1, Reactor Trip System (RTS} Instrumentation, Action 3.3.1.E, One Power Range Neutron Flux Low channel inoperable, requires an inoperable channel to be placed in Trip within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />. If the channel is not placed in Trip within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />, TS Action 3.3.1.T requires the unit to be in Mode 3 within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />. These actions were not completed, therefore creating a Condition Prohibited by TS. 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), Condition Prohibited by TS.
Cause of Event
Water intrusion into NI N-3-43 cabling.
Safety Significance
N-3-43 was inoperable for its low power range trip setpoint from November 14 to 19, 2024. During this period the 3 redundant channels were operable and fully capable of performing their safety functions.
This event did not result in a Safety System Functional Failure.
This event is being reported pursuant of 10 CFR 50. 73(a)(2)(i)(B), Condition Prohibited by TS.
Corrective Actions
The signal cable to N-3-43 was purged of water. Subsequent readings returned to normal and N-3-43 was declared operable on November 22, 2024.
Similar Events
A review of events over the past 5 years identified one similar event documented in LER 2020-05-01, Technical Specification Action Not Taken for Unrecognized Inoperable Source Range Channel, dated March 5, 2021. Page 2
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