05000424/LER-2025-001, Human Performance Error Results in Loss of Main Feedwater Pump and Manual Reactor Trip
| ML25205A149 | |
| Person / Time | |
|---|---|
| Site: | Vogtle  |
| Issue date: | 07/24/2025 |
| From: | Weissinger J Southern Nuclear Operating Co |
| To: | Office of Nuclear Reactor Regulation, Document Control Desk |
| References | |
| NL-25-0262 LER 2025-001-00 | |
| Download: ML25205A149 (1) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(iv)(A), System Actuation 10 CFR 50.73(a)(2) |
| 4242025001R00 - NRC Website | |
text
A Southern Nuclear July 24, 2025 Docket No.:
50-424 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D. C. 20555-0001 John Weissinger Site Vice President Vogtle Units 1*2 Vogtle Electric Generating Plant (VEGP) - Unit 1 Licensee Event Report 2025-001-00 7~1l(hc11m
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NL-25-0262 Human Performance Error Results in Loss of Main Feedwater Pump and Manual Reactor Trip Ladies and Gentlemen:
In accordance with the requirements of 1 O CFR 50.73(a)(2)(iv)(A), Southern Nuclear Operating Company hereby submits the enclosed Licensee Event Report (LEA), 2025-001-00 for Vogtle Electric Generating Plant (VEGP) Unit 1.
This letter contains no NRC commitments. If you have any questions, please contact the Vogtle Licensing Manager, Jamaal Merriweather at (706) 848-1422.
Respectfully submitted, John Weissinger Site Vice President Vogtle 1& 2 HJW/JJD Enclosure: LEA 2025-001-00 cc:
NRC Regional Administrator, Region II NRR Project Manager - Vogtle 1 & 2 Senior Resident Inspector - Vogtle 1 & 2 RType: CVC7000
U. S. Nuclear Regulatory Commission NL-25-001-00 Page 2 Vogtle Electric Generating Plant (VEGP) - Unit 1 Licensee Event Report 2025-001-00 Human Performance Error Results in Loss of Main Feedwater Pump and Manual Reactor Trip Enclosure LEA 2025-001-00
NRC FOAM 386 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY 0MB: NO. 3151H1104 EXPIRE8:M'30/'lm7 (04,02-2024)
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- 2. Docket Numbar 00424 1 OF 2
Human Performance Error Results in Loss of Main Feedwater Pump and Manual Reactor Trip
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- 11. Thia Report la Submitted Pursuant to the Requirements of 10 CFA t: (Check 1111 that apply}
D 20.2203(a)(2)(vl) 20.2201(b)
D 20.2203()(3)(1) 20.2201(d)
D 20.2203()(3)(11) 20.2203(1)(1)
D 20.2203()(4) 20.2203(*)(2)(1)
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D 20.2203(*)(2)(111)
D D 20.2203(a)(2)(1v)
D D 20.2203{a)(2Kv)
D OTHER (Specify here, In abstract, or NAC 366A}.
lJcellNt!Conlael Jamaal Merriweather, Vogtle licensing Manager
&0.73(1)(2)(ll)(A)
&0.38(c)(1 )(l)(A) 50, 73(*)(2)(11)(8) 50.38(c)(1 )(ll)(A)
ISO. 73(a)(2)(111) 50.3t(c)(2) 0 50. 73(1)(2)(lv)(A) 50.48()(3)(11) 50.73(a)(2){v)(A) 50.69(g)
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50.73(a)(2)(vlll)(8) 73.1200(b) 50,73(a)(2)(1x)(A)
D 73.1200(c) 50.73(*)(2)(*)
D 73.1200(d)
D 73.1200(e) 73,77(a)(1) 73.1200(1) 73.77(a)(2)(1)
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Phone Number (Include.... ciode) 706-848-1422 13, Complete One Une for each Component Failure Described In this Report CHM System Component
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- 14. Supplemental Aepon Expected
~ No D Yes (If yes, complete 15. Expected Submission Date)
- 15. Expec:tad Submluion Date
Abstract
At 1253 EDT, on May 28, 2025, with Unit 1 in Mode 1 at 100% power, the reactor was manually tripped due to the loss of Main Feedwater Pump (MFP) 'A'. While operators were swapping to the redundant lube oil cooler on the 1A MFP, the non-licensed operator rotated the 1A MFP lube oil cooler inlet 3-way valve past the valve stop device, causing the 1A MFP to automatically trip on low lube oil pressure and prompting the Control Room operators to manually trip the reactor. The trip was not complex, with all systems responding normally post-trip. Units 2, 3, and 4 were not affected. The operators in the Control Room pelformed as expected. The unit was stabilized in Mode 3 with decay heat being removed through the Steam Dumps into the Condenser.
The valve stop device tor the 1A MFP lube oil cooler inlet 3-way valve will be repaired at the next opportunity. The procedure will also be revised to include cautions to alert the operator of a unit trip risk, as well as figures that demonstrate proper valve operation. Due to the actuation of the Reactor Protection System and the Auxiliary Feedwater System, this is being reported under 10 CFR 50.73(a)(2)(iv)(A).
07 24
NRC FORM 318A (04-0~-~,
U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMS: NO. 3150-4>104 EXPIRES: 04/30l2027 LICENSEE EVENT REPORT (LER)
CONTINUATION SHEET (See NUREG-1022, R.3 for Instruction and guidance for completing this fonn IOlQWwllum;,~1cam, 1, FACIUTY NAME r-,
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Vogtle Electric Generating Plant (VEGP), Unit 1 050 052
NARRATIVE
EVENT DESCRIPTION
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Washington.DC 20503. TheNRCrnaynatconllldorsponso1,andapeqonlsAD1rtqu1redto respond to, I cclec:liall ol inlcnnalion UM5S Che clocl-,i requesting ot /llplinQ '11 ~olleClion cisiu,s I c:urttntly valid 0MB conll~ IUllbel.
. 2. DOCKET NUMBER 00424 VEAR SEQUENTIAL EJ-1 '":,'"
REV NO.
- - I oo At 1253 EDT, on May 28, 2025, with Unit I in Mode I at 100% power, the reactor {EIIS: AC) was manually tripped due to the loss of Main Feedwater Pump (EllS: SJ) 'A'. While operators were swapping to the redundant lube oil cooler (EIIS: SL, CLR) on the IA Main Feedwater Pump (MFP), the non-licensed operator rotated the IA MFP lube oil cooler inlet 3-way valve (EIIS: SL, V) past the valve stop
~evice, causing the I A MFP to automatically trip on low lube oil pressure and prompting 1he Conlrol Room operators to manually trip lfle reactor. All control rods inserted on the trip. The trip was not complex, with all systems responding normally post-trip. The
- Pperators in the Control Room performed as expected. The unit was stabilized In Mode 3 with decay heat being removed through the Steam Dumps (EIIS: JI) into the Condenser (EIIS: SG, COND). There were no slructures, systems, or components (SSCs) that were out p f service or inoperable at the beginning of the event that contribu1ed to the event. Due to the actuation of the Reactor Protection System (EIIS: JC) and Auxiliary Feedwater (EJIS: BA), this event is reportable under IO CFR 50.73(a)(2)(iv)(A). The componenl that (ailed wa1 the valve stop device associated wilh the General Electric MFP lube oil inlet valve, which is a 3" cast steel 3-way valve.
~ AUSE OF EVENT:
rtbe event occurred due to a human performance error in manipulation of the valve.
lneffective work prac1ices also contributed to this event. Specifically, the risk assessmenl, pre-job briefing, and proficiency assessment
!Were inadequate in preventing the occurrence of this evenl. The system operating procedure failed to highlight the risk of swapping oil
~oolers while online/in-service. There were also labeling deficiencies associated with the 3-way valve, making the indications on 1he
!Valve difficult to recognize. Only utility personnel (i.e., non-licensed and licensed operators) were involved with this event.
SAFETY ASSESSMENT
There were no safety consequences as a result of this event. The opera1ing crew responded correctly to the event The Condensate and Feedwatcr Malfunction Abnormal Operating Procedure and the Reactor Trip Response Emergency Operating Procedure were properly entered and perfonned to stabilize the plant. Systems and components needed to shutdown the reactor and maintain it in a safe shutdown condition were available. This event was within the analysis of the Upda1ed Final Safely Analysis Report, Chapter IS, Accident Analysis. No radioactivity release occurred. Unils 2, 3, and 4 were not affected.
t'ORRECTIVE ACTIONS:
iThe valve stop device for the IA MFP lube oil cooler inlel 3-way valve will be repaired at the next available opporlunity. The system operating procedure will also be revised to include cautions to alert the operator of a unit trip risk, as well as figures that demonstrale proper valve operation. The labeling for each MFP lube oil cooler inlet 3-way valve will also be enhanced by installing placards that
.;!early highlight the correct port for each lube oil cooler, as well as the correct direction to turn the valve when swapping lube oil coolers Formal !raining will be performed on multi-way valve operation for non-licensed and licensed operators.
l,JREVlOUS SIMILAR EVENTS:
None NRC FORM 386A (04-02,202~1 Page 2
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