05000250/LER-2024-004, Unplanned Reactor Scram
| ML25031A065 | |
| Person / Time | |
|---|---|
| Site: | Turkey Point  |
| Issue date: | 01/31/2025 |
| From: | Mack K Florida Power & Light Co |
| To: | Office of Nuclear Reactor Regulation, Document Control Desk |
| References | |
| L-2025-022 LER 2024-004-00 | |
| Download: ML25031A065 (1) | |
| Event date: | |
|---|---|
| Report date: | |
| 2502024004R00 - NRC Website | |
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U. S. Nuclear Regulatory Commission Attn: Document Control Desk Washington D C 20555-0001 RE: Turkey Point Nuclear Plant, Unit 3 Docket Nos. 50-250 Subsequent Renewed Facility Operating Licenses DPR-31 Reportable Event: 2024-04 Event Date: December 04, 2024 Unplanned Reactor Scram January 31, 2025 L-2025-022 10 CFR 50.73 The attached Licensee Event Report 2024-04 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 submittal, please contact Ms. Maribel Valdez, Fleet Licensing Manager, at 561-904-5164.
Sincerely,
~
b,A, Director, Licensing and Regulatory Compliance Florida Power and Light Company cc:
USNRC Regional Administrator, Region II USNRC Project Manager, Turkey Point Nuclear Plant USNRC Senior Resident Inspector, Turkey Point Nuclear Plant Mr. Clark Eldredge, Florida Department of Health Florida Power & Light Company 9760 SW 344th Street, Homestead, FL 3303S
Abstract
On December 4, 2024, at 1033 EST, while in Mode 1 with Unit 3 at 100 percent power, the reactor automatically tripped in response to a Reactor Protection System (RPS} [EIIS: JE] channel failure while planned maintenance was in progress on a redundant channel. An actuation of the Auxiliary Feedwater System (AFW} [EIIS: BAJ occurred and started as designed. The cause of the RPS channel failure was from a random failure of the channel's circuit cards. Other than the redundant channel removed from service for maintenance, 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}(iv)(A), for any event or condition resulted in the manual actuation or automatic action of RPS and AFW.
Description of Event
- 2. DOCKET NUMBER
- 3. LER NUMBER I
00250 D
NUMBER NO.
I YEAR SEQUENTIAL REV
~-I 04 1-G On December 4, 2024, at 1033 EST, while in Mode 1 with Unit 3 at 100 percent power, the reactor automatically tripped in response to a Reactor Protection System (RPS) [EIIS: JE] channel failure while planned maintenance was in progress on a redundant channel. Specifically, while maintenance was being performed on Power Range Monitors [EIIS: JI] channel 2.
An actuation of the AFW occurred and started as designed. Other than the redundant channel removed from service for maintenance, there were no Systems, Structures, or Components that were inoperable at the start of the event that contributed to the event.
Cause of Event
The RPS channel 2 loop calculation and associated data link handler printed circuit cards randomly failed while within their expected useful life.
Safety Significance
This event resulted in an unplanned shutdown and an NRC reportable event. In addition, there was a Safety Injection (SI) signal, therefore resulting in a Complicated Scram.
This event is being reported pursuant of 10 CFR 50. 73(a)(2)(iv)(A), for any event or condition that resulted in the manual actuation or automatic actuation of RPS and AFW.
This event did not result in a Safety System Functional Failure.
Corrective Actions
The failed RPS cards were replaced with new cards.
Similar Events
A review of events over the past 5 years identified one similar event documented in LER 2021-01, Automatic Reactor Trip due to Reactor Trip Breaker Cell Switch Malfunction, dated April 29, 2021. Page 2
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