05000482/LER-2024-001-01, Mode 3 Entry with One Auxiliary Feedwater Pump Train Inoperable Due to Missed Post-Maintenance Testing

Mode 3 Entry with One Auxiliary Feedwater Pump Train Inoperable Due to Missed Post-Maintenance Testing

ML24296A068
Person / Time
Site:	Wolf Creek
Issue date:	10/22/2024
From:	Bayer R Wolf Creek
To:	Office of Nuclear Reactor Regulation, Document Control Desk
References
000664 LER 2024-001-01
Download: ML24296A068 (1)

LER-2024-001, Mode 3 Entry with One Auxiliary Feedwater Pump Train Inoperable Due to Missed Post-Maintenance Testing

Event date:
Report date:
Reporting criterion:	10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications
4822024001R01 - NRC Website

text

P.O. Box 411 l Burlington, KS 66839 l 620-364-8831 Robert J. Bayer Plant Manager October 22, 2024 000664 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555 Reference:

Letter 000523, dated July 2, 2024, from R. J. Bayer, WCNOC, to USNRC Subject:

Docket No. 50-482: Licensee Event Report 2024-001-01, Mode 3 Entry with One Auxiliary Feedwater Pump Train Inoperable due to Missed Post-Maintenance Testing Commissioners and Staff:

The Reference submitted Licensee Event Report (LER) 2024-001-00, Mode 3 Entry with One Auxiliary Feedwater Pump Train Inoperable due to Missed Post-Maintenance Testing. The enclosed supplement revises the cause and corrective actions. LER 2024-001-01 is being submitted pursuant to 10 CFR 50.73(a)(2)(i)(B) regarding an operation or condition prohibited by Wolf Creek Generating Stations Technical Specifications.

This letter contains no commitments. If you have any questions concerning this matter, please contact me at (620) 364-4015, or Dustin Hamman at (620) 364-4204.

Sincerely, Robert J. Bayer RJB/jkt Enclosure:

LER 2024-001-01 (

Abstract

Wolf Creek Generating Station

00482 3

Mode 3 Entry with One Auxiliary Feedwater Pump Train Inoperable due to Missed Post-Maintenance Testing 05 09 2024 2024 001 01 10 22 2024 3

00

Jason Knust, Lead Licensing Engineer 620-364-8831

At 2330 Central Daylight Time (CDT) on 5/9/2024, during mode ascension coming out of Refueling Outage 26 (RF26), it was discovered that no post-maintenance testing had been performed on three air operated discharge valves which had maintenance performed on them during RF26. These valves provide flow from the turbine driven auxiliary feedwater pump to the steam generators. This discovery was made after the unit had gone from Mode 4 to Mode 3. With no post-maintenance testing performed on these three valves, they would have to be declared out of service which would cause the turbine driven AFW pump train to be inoperable in Mode 3. Because one required train of AFW was inoperable, LCO 3.7.5 was not met when the unit entered into Mode 3. Immediately following discovery, WCGS personnel began the process of testing the three valves. By 0215 CDT on 5/10/2024, testing was finished with all three valves having passed satisfactorily. The valves were returned to service at this time and the turbine driven AFW pump train was declared operable. TS LCO 3.0.4 only allows entry into a Mode of applicability for an unmet LCO when certain requirements are met. However, none of these requirements were met. Therefore, upon entry into Mode 3, WCGS violated TS LCO 3.0.4. This event is therefore reportable per 10 CFR 50.73(a)(2)(i)(B) as an operation or condition prohibited by TS. Page of

3. LER NUMBER YEAR SEQUENTIAL NUMBER REV NO.

052 050 EVENT DESCRIPTION (cont.)

c. When an allowance is stated in the individual value, parameter, or other Specification.

Required Action C.1 of LCO 3.7.5 has a 72-hour Completion Time, so continued operation in this Condition is time limited; no specific risk assessment was performed for entry into Mode 3 with the turbine driven AFW pump train inoperable; and there are no allowances in LCO 3.7.5 (or any other Specification) for entry into Mode 3 with the turbine driven AFW pump train inoperable. Therefore, none of the requirements of LCO 3.0.4 were met when WCGS entered Mode 3 with LCO 3.7.5 not met.

BASIS FOR REPORTABILITY From the time the unit entered Mode 3 until the testing was completed and the valves restored to service, the unit would have been in Condition C for approximately 42 1/2 hours. This is less than the 72-hour Completion Time to restore the turbine driven AFW pump train to operable status. As such, LCO 3.7.5 was not violated. However, the unit did enter Mode 3 while not meeting LCO 3.7.5. None of the requirements stated in LCO 3.0.4 were met during this time so WCGS was in violation of LCO 3.0.4. Therefore, this event is reportable per 10 CFR 50.73(a)(2)(i)(B) as an operation or condition prohibited by TS.

CAUSE In the NRC 2nd Quarter Integrated Inspection report for WCGS, a semi-annual trend was identified based on a number of examples of improperly planning or performing PMTs. A causal evaluation was done that incorporated these examples including the issue that is discussed in this report. The probable cause was determined to be a decrease in the proficiency and experience levels of personnel to promote adequate implementation of the PMT program.

CORRECTIVE ACTIONS Immediate corrective actions included performing the missed post-maintenance testing, and once completed satisfactorily, declaring the turbine driven AFW pump train operable. Corrective actions that have been taken or are in progress include SROs participating in discussions, as well as teaching and learning sessions with Operations leadership and Shift Managers regarding developing PMT plans and acceptable tracking methods. Corrective actions planned include developing and presenting a PMT seminar with planners to discuss the PMT procedure, operating experience, and a learning activity to plan a PMT.

SAFETY SIGNIFICANCE The safety significance of this event was low. All three valves successfully passed their post-maintenance testing the first time. Therefore, had there been an event that would have required the AFW system to operate during the time the unit was in Mode 3 prior to testing the valves, all three trains of the system would have been capable of performing their intended functions. In addition, both motor driven AFW pump trains were verified to be operable prior to entering Mode 3.

OPERATING EXPERIENCE/PREVIOUS EVENTS A search of the corrective action program revealed that there have been no occurrences of making a Mode change not allowed by LCO 3.0.4 at WCGS in the past three years.

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Wolf Creek Generating Station 00482 2024 001 01