05000321/LER-2024-004, Nuclear Plant, Unit 1 Manual Reactor Trip During Hurricane Helene Due to Degrading Condenser Vacuum
| ML24324A187 | |
| Person / Time | |
|---|---|
| Site: | Hatch  |
| Issue date: | 11/19/2024 |
| From: | Busch M Southern Nuclear Operating Co |
| To: | Office of Nuclear Reactor Regulation, Document Control Desk |
| References | |
| NL-24-0413 LER 2024-004-00 | |
| Download: ML24324A187 (1) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(iv)(A), System Actuation |
| 3212024004R00 - NRC Website | |
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-~ Southern Nuclear Matt Busch Vice President - Plant Hatch November 19, 2024
!latch 'lurlcar Plant I I 028 !latch Parkway :sionh Baxlcy.c;,\ 31513 912 537 SR59 tel 912 366 2077 fax Docket Nos.: 50-321 NL-24-0413 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D. C. 20555-0001 Edwin I. Hatch Nuclear Plant Licensee Event Report 2024-004-00 Unit 1 Manual Reactor Trip During Hurricane Helene Due to Degrading Condenser Vacuum Ladies and Gentlemen:
In accordance with the requirements of 10 CFR 50.73 (a)(2)(iv)(A), Southern Nuclear Operating Company hereby submits the enclosed Licensee Event Report.
This letter contains no NRC commitments. If you have any questions, please contact the Hatch Licensing Manager, Jimmy Collins, at 912.453.2342.
Respectfully submitted, Matt Busch Vice President - Hatch MSB/JMH Enclosure: LER 2024-004-00 Cc:
Regional Administrator, Region II NRR Project Manager - Hatch Senior Resident Inspector - Hatch RTYPE: CHA02.004
Enclosure to NL-24-0413 LER 2024-004-00 Edwin I. Hatch Nuclear Plant Licensee Event Report 2024-004-00 Unit 1 Manual Reactor Trip During Hurricane Helene Due to Degrading Condenser Vacuum Enclosure LER 2024-004-00
Abstract
At 0346 EDT on 9/27/24, with Unit 1 in Mode 1 at approximately 54% power, the reactor was manually tripped due to degrading condenser vacuum. The trip was not complex, with all systems responding normally including the closure of containment isolation valves in multiple systems. The Operating crew responded correctly to the event and the plant was stabilized.
The degrading condenser vacuum was caused by debris from Hurricane Helene that accumulated and clogged the circulation water screens of the Unit 1 flume. The circulation water system was shutdown and the debris removed from the Unit 1 circulation water screens.
The event is reportable per 10 CFR 50.73(a)(2)(iv)(A) as any event or condition that resulted in the manual or automatic actuation of any of the systems listed in paragraph (a)(2)(iv)(B) of this section. Systems that actuated during this event that are listed in (a)(2)(iv)(B) include: the Reactor Protection System (RPS) and general Containment Isolation Valves (CIV) in multiple systems.
EVENT DESCRIPTION
I
- 2. DOCKET NUMBER
- 3. LER NUMBER 00321 I
YEAR SEQUENTIAL REV c::7 NUMBER NO.
~-I 004 1-G At 0346 EDT on 9/27/24, with Unit 1 in Mode 1 at approximately 54% power, the reactor was manually tripped due to degrading condenser vacuum. The trip was not complex, with all systems responding normally including the closure of containment isolation valves {CIV)(EIIS Code: ISV) in multiple systems. The Operating crew responded correctly to the event and the plant was stabilized. There were no inoperable systems that contributed to this event.
EVENT CAUSE ANALYSIS
The degrading condenser vacuum was caused by debris from Hurricane Helene that accumulated and clogged the circulation water screens of the Unit 1 flume.
SAFETY ASSESSMENT AND REPORTABILITY
There were no actual safety consequences as a result of this event. All safety related systems functioned as designed during this event. The Operating crew responded correctly to the event. The applicable abnormal / emergency operating procedures were properly entered and the plant was stabilized. The event was within the analysis of the Updated Final Safety Analysis Report (UFSAR) Chapter 15.
The event is reportable per 10 CFR 50.73(a)(2)(iv)(A) as any event or condition that resulted in the manual or automatic actuation of any of the systems listed in paragraph (a)(2)(iv)(B) of this section. Systems that actuated during this event that are listed in (a)(2)(iv)(B) include: the Reactor Protection System (RPS)(EIIS Code: IG) and general Containment Isolation Valves (CIV) in multiple systems.
CORRECTIVE ACTIONS
The circulation water system was shutdown and the debris removed from the Unit 1 circulation water screens.
PREVIOUS SIMILAR EVENTS
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