ML25128A008
| ML25128A008 | |
| Person / Time | |
|---|---|
| Site: | Davis Besse  |
| Issue date: | 05/09/2025 |
| From: | Sanchez-Santiago E NRC/RGN-III/DORS/RPB2 |
| To: | Tony Brown Vistra Operations Company |
| References | |
| IR 2025001 | |
| Download: ML25128A008 (1) | |
Text
Terry Brown Site Vice President Vistra Operations Company, LLC Davis-Besse Nuclear Power Station 5501 N. State Rte. 2, Mail Stop A-DB-3080 Oak Harbor, OH 43449-9760
SUBJECT:
DAVIS-BESSE NUCLEAR POWER STATION-INTEGRATED INSPECTION REPORT 05000346/2025001
Dear Terry Brown:
On March 31, 2025, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection at Davis-Besse Nuclear Power Station. On April 10, 2025, the NRC inspectors discussed the results of this inspection with you and other members of your staff. The results of this inspection are documented in the enclosed report.
No NRC-identified or self-revealing findings were identified during this inspection.
A licensee-identified violation which was determined to be of very low safety significance is documented in this report. We are treating this violation as a non-cited violation (NCV) consistent with Section 2.3.2 of the Enforcement Policy.
If you contest the violation or the significance or severity of the violation documented in this inspection report, you should provide a response within 30 days of the date of this inspection report, with the basis for your denial, to the U.S. Nuclear Regulatory Commission, ATTN: Document Control Desk, Washington, DC 20555-0001; with copies to the Regional Administrator, Region III; the Director, Office of Enforcement; and the NRC Resident Inspector at Davis-Besse Nuclear Power Station.
May 9, 2025
T. Brown 2
This letter, its enclosure, and your response (if any) will be made available for public inspection and copying at http://www.nrc.gov/reading-rm/adams.html and at the NRC Public Document Room in accordance with Title 10 of the Code of Federal Regulations 2.390, Public Inspections, Exemptions, Requests for Withholding.
Sincerely, Elba M. Sanchez Santiago, Chief Reactor Projects Branch 2 Division of Operating Reactor Safety Docket No. 05000346 License No. License No. NPF-3
Enclosure:
As stated cc: Distribution via LISTSERV Signed by Sanchez Santiago, Elba on 05/09/25
SUNSI Review
Non-Sensitive
Sensitive
Publicly Available
Non-Publicly Available OFFICE RIII RIII NAME RNg:gmp ESanchezSantiago DATE 05/08/2025 05/09/2025
Enclosure U.S. NUCLEAR REGULATORY COMMISSION Inspection Report Docket Number:
05000346 License Number:
NPF-3 Report Number:
05000346/2025001 Enterprise Identifier:
I2025001-0062 Licensee:
Vistra Operations Company, LLC Facility:
Davis-Besse Nuclear Power Station Location:
Oak Harbor, OH Inspection Dates:
January 01, 2025 to March 31, 2025 Inspectors:
R. Cassara, Resident Inspector B. Towne, Senior Resident Inspector Approved By:
Elba M. Sanchez Santiago, Chief Reactor Projects Branch 2 Division of Operating Reactor Safety
2
SUMMARY
The U.S. Nuclear Regulatory Commission (NRC) continued monitoring the licensees performance by conducting an integrated inspection at Davis-Besse Nuclear Power Station, in accordance with the Reactor Oversight Process. The Reactor Oversight Process is the NRCs program for overseeing the safe operation of commercial nuclear power reactors. Refer to https://www.nrc.gov/reactors/operating/oversight.html for more information. A licensee-identified non-cited violation is documented in report section: 71111.11Q.
List of Findings and Violations No findings or violations of more than minor significance were identified.
Additional Tracking Items None.
3 PLANT STATUS Davis-Besse operated at or near rated thermal power for the entire inspection period.
INSPECTION SCOPES Inspections were conducted using the appropriate portions of the inspection procedures (IPs) in effect at the beginning of the inspection unless otherwise noted. Currently approved IPs with their attached revision histories are located on the public website at http://www.nrc.gov/reading-rm/doc-collections/insp-manual/inspection-procedure/index.html. Samples were declared complete when the IP requirements most appropriate to the inspection activity were met consistent with Inspection Manual Chapter (IMC) 2515, Light-Water Reactor Inspection Program - Operations Phase. The inspectors performed activities described in IMC 2515, Appendix D, Plant Status, observed risk significant activities, and completed onsite portions of IPs. The inspectors reviewed selected procedures and records, observed activities, and interviewed personnel to assess licensee performance and compliance with Commission rules and regulations, license conditions, site procedures, and standards.
REACTOR SAFETY 71111.04 - Equipment Alignment Partial Walkdown Sample (IP Section 03.01) (3 Samples)
The inspectors evaluated system configurations during partial walkdowns of the following systems/trains:
(1)
Auxiliary feedwater train 2 during quarterly test of auxiliar feedwater pump 1 on January 24, 2025 (2)
Decay heat/low pressure injection train 1 while train 1 is the protected train during the week ending February 15, 2025 (3)
Component cooling water (CCW) train 1 while shifting CCW in service train to train 2 on March 19, 2025 71111.05 - Fire Protection Fire Area Walkdown and Inspection Sample (IP Section 03.01) (5 Samples)
The inspectors evaluated the implementation of the fire protection program by conducting a walkdown and performing a review to verify program compliance, equipment functionality, material condition, and operational readiness of the following fire areas:
(1)
Emergency core cooling system (ECCS) pump room train 1, fire area AB01 on January 8, 2025 (2)
Condensate storage tank room 345, fire area II on January 13, 2025 (3)
Control room emergency ventilation system (CREVS) equipment room 603 and 603A, fire area HH on January 30, 2025 (4)
Service water pipe tunnel, room 250, fire area BG, during the week ending March 1, 2025 (5)
Emergency diesel generator (EDG) 2 room, rooms 319 and 318A, fire area J on March 26, 2025
4 71111.11Q - Licensed Operator Requalification Program and Licensed Operator Performance Licensed Operator Performance in the Actual Plant/Main Control Room (IP Section 03.01)
(2 Samples)
(1)
The inspectors observed and evaluated licensed operator performance in the control room as they performed a down power to 99.5 percent and took actions to place the integrated controller system in manual to swap feedwater inlet temperature instruments on February 27, 2025 (2)
The inspectors observed and evaluated licensed operator performance in the control room during a down power to 95 percent for control rod exercise test, main turbine stop valve testing, main turbine control valve testing, and main turbine combined intermediate valve testing on March 14, 2025 Licensed Operator Requalification Training/Examinations (IP Section 03.02) (1 Sample)
(1)
The inspectors observed and evaluated licensed operator performance in the simulator and classroom during licensed operator training on February 20, 2025 71111.12 - Maintenance Effectiveness Maintenance Effectiveness (IP Section 03.01) (2 Samples)
The inspectors evaluated the effectiveness of maintenance to ensure the following structures, systems, and components remain capable of performing their intended function:
(1)
Maintenance rule (a)(1) evaluation for the auxiliary boiler following engineering modification and maintenance outage during the week of February 17, 2025 (2)
Maintenance rule evaluation of the EDG air compressor 3 due to tripping on overload and not shutting off a setpoint, lifting the air reservoir on March 11, 2025 71111.13 - Maintenance Risk Assessments and Emergent Work Control Risk Assessment and Management Sample (IP Section 03.01) (3 Samples)
The inspectors evaluated the accuracy and completeness of risk assessments for the following planned and emergent work activities to ensure configuration changes and appropriate work controls were addressed:
(1)
Assessment of elevated risk and mitigating actions due to extreme cold weather alert during the week ending January 11, 2025 (2)
Assessment of elevated risk and mitigating actions due to maintenance on high pressure injections (HPI) train 1 minimum flow recirculating stop check valve on March 25, 2025 (3)
Inspection of mitigating fire risk actions as prescribed by the fire hazards analysis report (FHAR) due to EDG 2 room fire detection out of service during the week ending March 28, 2025
5 71111.15 - Operability Determinations and Functionality Assessments Operability Determination or Functionality Assessment (IP Section 03.01) (5 Samples)
The inspectors evaluated the licensees justifications and actions associated with the following operability determinations and functionality assessments:
(1)
Operability determination of safety features actuation system (SFAS) channel 1 due to sequencer failure during SFAS functional test on January 22, 2025 (2)
Operability determination of control room envelope and CREVS train 1 due to air inleakage above the limit for acceptance criteria on January 30, 2025 (3)
Operability determination of feedwater inlet temperature due to temperature channel divergence during the week ending March 1, 2025 (4)
Operability determination of makeup pumps due to makeup pump room AC failure with temperatures approaching the limit for operability on March 10, 2025 (5)
Operability determination of core flood tank 1 level instrumentation due to diverging trend in level between channels, during the week ending March 29, 2025 71111.18 - Plant Modifications Temporary Modifications and/or Permanent Modifications (IP Section 03.01 and/or 03.02)
(2 Samples)
The inspectors evaluated the following temporary or permanent modifications:
(1)
CREVS access door seal modification during the week ending February 8, 2025 (2)
Emergency feedwater new battery and charger system during the week ending March 8, 2025 71111.24 - Testing and Maintenance of Equipment Important to Risk The inspectors evaluated the following testing and maintenance activities to verify system operability and/or functionality:
Post-Maintenance Testing (PMT) (IP Section 03.01) (7 Samples)
(1)
EDG 1 following work on the air start system on January 2, 2025 (2)
Station blackout diesel generator after maintenance on air start compressor during the week ending January 11, 2025 (3)
SFAS channel 1 after replacement of sequencer during the week ending January 25, 2025 (4)
PMT of the control room emergency ventilation system following temporary modification of the access door downstream of the charcoal filter to correct air inleakge on February 1, 2025 (5)
PMT of HP32 HPI train 1 minimum flow recirculating stop check valve following diagnostic static testing on March 25, 2025 (6)
PMT of MU6421 alternate reactor coolant system makeup isolation valve following motor-operated valve (MOV) breaker replacement on March 20, 2025 (7)
PMT of diesel fire pump following scheduled maintenance and overspeed limiting device replacement during the week ending March 8, 2025
6 Surveillance Testing (IP Section 03.01) (4 Samples)
(1)
Auxiliary feedwater pump 1 quarterly test on January 24, 2025 (2)
Offsite dose calculation manual license condition requirement for storm sewer flow rate calculation/estimation due to failed flow rate instrument, on February 20, 2025 (3)
Calibration of the seismic monitoring system during the week ending March 1, 2025 (4)
Station air compressor 1 after scheduled maintenance during the week ending January 25, 2025 Inservice Testing (IST) (IP Section 03.01) (1 Sample)
(1)
Auxiliary feed pump train 2 inservice testing during the week ending March 8, 2025 Diverse and Flexible Coping Strategies (FLEX) Testing (IP Section 03.02) (1 Sample)
(1)
Turbo Marine FLEX diesel generators during the week ending February 8, 2025 OTHER ACTIVITIES-BASELINE 71152S - Semiannual Trend Problem Identification and Resolution Semiannual Trend Review (Section 03.02) (1 Sample)
(1)
The inspectors reviewed the corrective action program for trends in measuring and test equipment (M&TE) readiness that might be indicative of a more significant safety issue. Inspectors identified a trend of documented instances of M&TE not being available for scheduled surveillances, was out of calibration, or was not in stock and equivalent equipment had to be identified. The inspectors reviewed associated documents to ensure there weren't any delayed, missed, or improperly performed surveillance on safety systems as a result of this trend. The adverse trend was communicated to the licensee and entered into the corrective action program. No issue of significance was identified.
INSPECTION RESULTS Licensee-Identified Non-Cited Violation 71111.11Q This violation of very low safety significance was identified by the licensee and has been entered into the licensee corrective action program and is being treated as a non-cited violation, consistent with Section 2.3.2 of the Enforcement Policy.
Violation: Technical Specification Section 5.4.1.a requires, in part, that written procedures shall be established, implemented, and maintained covering the applicable procedures recommended in Regulatory Guide 1.33, Revision 2, Appendix A, February 1978.
NRC Regulatory Guide 1.33, Revision 2, Appendix A, Section 7 addresses Procedures for Control of Radioactivity (For limiting materials released to environment and limiting personnel exposure) and Section 7.e, addresses Radiation Protection Procedures.
The licensee established procedure NOP-OP4301, "Respiratory Protection Program,
" Rev. 10, October 20, 2017, to address, in part, the program requirements for respiratory protection at all licensee facilities against all industrial hazards, including those that may be radioactive, in accordance with 10CFR20 and 29CFR1910.134. Procedure NOP-OP4301,
7 Rev. 10, Step 4.1.6.1 states: Department and contractor supervision shall ensure compliance of all applicable respirator procedures for employees working under their direction. Step 4.1.6.6 requires the licensee to: Maintain emergency respirator qualification, when required, for employees working under their direction. This includes ensuring that employees who may be required to don emergency respirators maintain respirator glasses, if applicable, and are clean-shaven. Step 4.6.7.3 requires: Active NRC-licensed personnel who have a corrective lens requirement as a license condition shall maintain appropriate corrective lenses readily available for emergency respirator use.
Contrary to the above, from October 2, 2023 to January 16, 2025, the licensee failed to implement procedures as required by TS 5.4.1.a. Specifically, the licensee failed to implement steps 4.1.6.1, 4.1.6.6, and 4.6.7.3 of procedure NOP-OP4301 when facility managers/supervisors failed to ensure compliance of all applicable respirator procedures for employees working under their direction and failed to ensure that the licensed operator properly maintained a set of respirator glasses. The licensed operator, who had a corrective lens requirement as a license condition, failed to properly maintain the appropriate corrective lenses readily available for emergency respirator use.
Significance/Severity: Green. The inspectors assessed the significance of the finding using IMC 0609 Appendix C, Occupational Radiation Safety Significance Determination Process.
The inspectors determined that the finding is not related to ALARA, does not involve an overexposure, does not have a substantial potential for overexposure, did not compromise the licensee's ability to assess dose, and therefore screens to Green, or very low safety significance.
Corrective Action References: CR202500314 Licensed Individual Did Not Have Personal Spectacle Kit Available in the CTRM EXIT MEETINGS AND DEBRIEFS The inspectors verified no proprietary information was retained or documented in this report.
On April 10, 2025, the inspectors presented the integrated inspection results to T. Brown, Site Vice President, and other members of the licensee staff.
8 DOCUMENTS REVIEWED Inspection Procedure Type Designation Description or Title Revision or Date DBOP06012 Decay Heat and Low Pressure Injection System Operating Procedure 86 DBOP06233 Auxiliary Feedwater System 49 71111.04 Procedures DBOP06262 Component Cooling Water System Procedure 48 PFP-AB105 ECCS Pump Room 11, Fire Area AB01 09 PFP-AB319 Diesel Generator 12 Room, Rooms 319 and 318A, Fire Area J 8
PFP-AB603 AC Equipment Room and Records and Storage, Room 603 and 603A, Fire Area HH 05 PFP-TB250 Service Water Pipe Tunnel, Room 250, Fire Area BG 5
71111.05 Fire Plans PFP-TB345 Condensate Storage Tank Area, Room 345, Fire Area II 04 Corrective Action Documents CR202501772 Unexpected Alarm While Testing Main Turbine Combined Intercept Valves 03/14/2025 DBSC03272 Control Rod Exercising Test 7
DBSC04150 Main Turbine Stop Valve Test 20 DBSC04152 Main Turbine Combined Intermediate Valve Test 14 DBSc004151 Main Turbine Control Valve Test 18 71111.11Q Procedures OPS-GOP-S102 Simulator Guide 1
CR202408778 SV3915 Aux Boiler Atomizing Steam Inlet Solenoid Valve Plumbed Incorrectly 11/08/2024 CR202408830 Failed Relay During Commissioning Testing 11/10/2024 CR202409051 Spurious Trip During Commissioning 11/19/2024 CR202409384 Aux Boiler Failed to Fire 12/06/2024 CR202501604 EDG Compressor 3 Overload 03/09/2025 Corrective Action Documents CR202501650 EDG AC 3 (C113) Running Continuously 03/10/2025 71111.12 Procedures NOP-ER3004 Maintenance Rule Program 06 71111.13 Corrective Action Documents Resulting from Inspection CR202502149 Documentation of NRC Resident Question 03/26/2025
9 Inspection Procedure Type Designation Description or Title Revision or Date Miscellaneous FHAR Davis-Besse Nuclear Power Station Unit 1 Fire Hazards Analysis Report 30 CR202408828 Small Change Seen in Feedwater Temperature Trending 11/10/2024 CR202408996 Diverging Trent in CFT 1 Level Indicators 11/16/202 CR202500451 Did Not Receive All Expected Computer Points While Testing SFAS CH 1 Sequence 01/02/2025 Cr202500624 Control Room Unfiltered Leakage Greater than Acceptance Criteria 01/30/2025 Corrective Action Documents CR202501564 Makeup Pump Room AC Unit Not Blowing Air 03/07/2025 71111.15 Work Orders 200967888 Core Flood Tank 11 Level Transmitter Buffer Replacement 02/26/2025 Miscellaneous 251016-001 Design Equivalent Change Package 0
ECP210112-001 Replace EFWP Engine Start Battery Charger 08/07/2023 71111.18 Procedures ECP210113-001 Replace EFWP Engine Start Battery 07/18/2023 DBFP04047 Diesel Fire Pump Tes 18 DBFP04049 Diesel Fire Pump Tests 8
DBOP06412 Process and Area Radiation Monitor 56 DBPF03272 Post-Maintenance Valve Test 18 DBSC03070 Emergency Diesel Generator 1 Monthly Test 51 DBSC03110 SFAS Channel 1 Functional Test 25 DBSP03151 AFP 1 Quarterly Test 33 DBSP03160 AFP2 Quarterly Test 39 Procedures DBSS03301 Control Room Unfiltered Air Inleakage Test for Control Room Emergency Ventilation 00 200735037 Station Blackout Diesel Generator Air Start Post Maintenance Test 01/08/2025 200834963 AF05 Pressure Test 03/18/2025 200834964 AF07 Pressure Test 03/18/2025 200834965 AF08 Pressure Test 03/18/2025 200871152 Station Air Compressor 1 Maintenance 01/28/2025 200885668 Seismic Monitoring System Test 02/27/2025 200891520 FXK1P Functional Test 02/11/2025 71111.24 Work Orders 200891521 FXK1A Functional Test 02/11/2025
10 Inspection Procedure Type Designation Description or Title Revision or Date 200892861 PMT of HP32 HPI Train 1 MIN Flow Recirc Stop Check Valve 03/25/2025 200900042 Perform EDG 1 Monthly Test 01/02/2025 200900907 SFAS Channel 1 Functional Test 01/22/2025 200911500 PMT MU6421 ARCS Makeup Isolation Valve MOV BRKR Replacement 03/20/2025 200962090 Perform Quarterly Test on Aux Feedwater Pump 1 01/24/2025 200965529 CH 1 Sequence Module Replacement 01/22/2025 CR202409338 Rollup CR for Unavailability of Measuring & Test Equipment 12/03/2024 71152S Corrective Action Documents CR202500637 DB Maintenance 1H25 IPA - New Gap - Unavailability of Measuring & Test Equipment 01/30/2025