IR 05000338/2024001

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Integrated Inspection Report 05000338/2024001 and 05000339/2024001
ML24129A098
Person / Time
Site:  Dominion icon.png
Issue date: 05/10/2024
From: Matthew Fannon
NRC/RGN-II/DRP/RPB4
To: Carr E
Dominion Energy Co
References
IR 2024001
Download: ML24129A098 (25)
v • d • e


Text

SUBJECT:

NORTH ANNA POWER STATION, UNITS 1 AND 2 - INTEGRATED INSPECTION REPORT 05000338/2024001 AND 05000339/2024001

Dear Eric S. Carr:

On March 31, 2024, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection at North Anna Power Station, Units 1 and 2. On April 18, 2024, the NRC inspectors discussed the results of this inspection with Lisa Hilbert, Site Vice President, and other members of your staff. The results of this inspection are documented in the enclosed report.

Two findings of very low safety significance (Green) are documented in this report. One of these findings involved a violation of NRC requirements. 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 II; the Director, Office of Enforcement; and the NRC Resident Inspector at North Anna Power Station, Units 1 and 2.

If you disagree with a finding not associated with a regulatory requirement in this report, you should provide a response within 30 days of the date of this inspection report, with the basis for your disagreement, to the U.S. Nuclear Regulatory Commission, ATTN: Document Control Desk, Washington, DC 20555-0001; with copies to the Regional Administrator, Region II; and the NRC Resident Inspector at North Anna Power Station, Units 1 and 2May 10, 2024 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, Matthew S. Fannon, Chief Reactor Projects Branch 4 Division of Reactor Projects Docket Nos. 05000338 and 05000339 License Nos. NPF-4 and NPF-7

Enclosure:

As stated

Inspection Report

Docket Numbers: 05000338 and 05000339

License Numbers: NPF-4 and NPF-7

Report Numbers: 05000338/2024001 and 05000339/2024001

Enterprise Identifier: I-2024-001-0031

Licensee: Dominion Energy

Facility: North Anna Power Station, Units 1 and 2

Location: Mineral, VA

Inspection Dates: January 01, 2024, to March 31, 2024

Inspectors: J. Bell, Senior Health Physicist B. Bowker, Reactor Inspector B. Caballero, Senior Operations Engineer K. Carrington, Senior Resident Inspector B. Kellner, Senior Health Physicist N. Lacy, Operations Engineer D. Neal, Health Physicist D. Turpin, Resident Inspector

Approved By: Matthew S. Fannon, Chief Reactor Projects Branch 4 Division of Reactor Projects

Enclosure

SUMMARY

The U.S. Nuclear Regulatory Commission (NRC) continued monitoring the licensees performance by conducting an integrated inspection at North Anna Power Station, Units 1 and 2, 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.

List of Findings and Violations

Failure to Develop or Implement Preventive Maintenance Strategy in Accordance with Procedures Cornerstone Significance Cross-Cutting Report Aspect Section Mitigating Green None (NPP) 71152A Systems FIN 05000338,05000339/2024001-01 Open/Closed A self-revealed Green finding was identified for the licensee's failure to develop adequate preventive maintenance strategies for the 'A' and 'B' station blackout (SBO) diesel generator (DG) radiator fans in accordance with Dominion Procedure, ER-AA-PRS-1010, Preventive Maintenance Task Basis and Maintenance Strategy, Revision 16.

Failure to Perform Work In accordance with Procedures Results in Reactor Coolant System Pressure Boundary Weld Leak Cornerstone Significance Cross-Cutting Report Aspect Section Barrier Integrity Green None (NPP) 71153 NCV 05000339/2024001-02 Open/Closed A self-revealed Green finding and associated non-cited violation (NCV) of 10 CFR Part 50,

Appendix B, Criterion IX, Control of Special Processes, was identified when a deficient weld in reactor coolant system (RCS) piping failed and resulted in pressure boundary leakage from a Unit 2 pressurizer instrument line.

Additional Tracking Items

Type Issue Number Title Report Section Status URI 05000338,05000339/20 Moisture Intrusion Resulting 71111.12 Closed 23003-01 in Station Blackout (SBO)

Radiator Fan Motor Issues

LER 05000339/2023-001-00 LER 2023-001-00 for North 71153 Closed Anna Power Station, Unit 2,

Reactor Coolant Pressure Boundary Leak Due to Poor Weld Workmanship

PLANT STATUS

Unit 1 began the inspection period operating at or near 100 percent rated thermal power (RTP).

On March 3, 2024, the unit was shut down for refuel outage 1R30. The unit remained shut down through the end of the inspection period.

Unit 2 operated at or near 100 percent RTP 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 on-site 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

71111.01 - Adverse Weather Protection

Seasonal Extreme Weather Sample (IP Section 03.01) (1 Sample)

(1) The inspectors evaluated readiness for seasonal extreme weather conditions prior to the onset of seasonal cold temperatures for the following systems on January 23, 2024:
  • independent spent fuel storage installation modules; and

Impending Severe Weather Sample (IP Section 03.02) (1 Sample)

(1) The inspectors evaluated the adequacy of the overall preparations to protect risk-significant systems from impending severe weather (heavy rainfalls and wind gusts up to 50 mph), on January 9-10, 2024.

71111.04 - Equipment Alignment

Partial Walkdown Sample (IP Section 03.01) (2 Samples)

The inspectors evaluated system configurations during partial walkdowns of the following systems/trains:

(1) Unit 2 'B' low head safety injection system following quarterly testing, on February 16, 2024
(2) Unit 1 and Unit 2 shared spent fuel pit cooling system during Unit 1 core offload, on March 20, 2024

Complete Walkdown Sample (IP Section 03.02) (1 Sample)

(1) The inspectors evaluated system configurations during a complete walkdown of the Unit 1 inside recirculation spray system, on March 21, 2024.

71111.05 - Fire Protection

Fire Area Walkdown and Inspection Sample (IP Section 03.01) (3 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) Fire Area 2, main control room, on January 22, 2024
(2) Fire Zone 6-1, Unit 1 emergency switchgear room and air conditioning room, on February 14, 2024
(3) Fire Zone 6-2, Unit 2 emergency switchgear room and air conditioning room, on February 28, 2024

Fire Brigade Drill Performance Sample (IP Section 03.02) (1 Sample)

(1) The inspectors evaluated onsite fire brigade training and performance during unannounced fire drill 1-4, on February 13, 2024.

71111.07A - Heat Exchanger/Sink Performance

Annual Review (IP Section 03.01) (1 Sample)

The inspectors evaluated readiness and performance of:

(1) 1-RH-E-1A, Unit 1 'A' residual heat removal heat exchanger eddy current testing, on March 14-15, 2024

===71111.08P - Inservice Inspection Activities (PWR)

The inspectors verified that the reactor coolant system boundary, reactor vessel internals, risk-significant piping system boundaries, and containment boundary are appropriately monitored for degradation and that repairs and replacements were appropriately fabricated, examined and accepted by reviewing the following activities during Unit 1 refuel outage (RFO) 1R30 from March 11-14, 2024.

PWR Inservice Inspection Activities Sample - Nondestructive Examination and Welding Activities (IP Section 03.01)===

Main article: IP 71111.08

The inspectors verified that the following nondestructive examination and welding activities were performed appropriately:

(1) Ultrasonic Examination
  • 6-SI-132, weld SW-51, pipe to pipe, American Society of Mechanical Engineers (ASME) Class 1

Magnetic Particle Examination

  • 6-WFPD-10, weld SW-43, tee to elbow, Augmented

Dye Penetrant Examination

  • 3/4-RC-67, weld SW-74, sockolet, Augmented

Visual Examination

Welding Activities

PWR Inservice Inspection Activities Sample - Boric Acid Corrosion Control Inspection Activities (IP Section 03.03) (1 Sample)

The inspectors verified the licensee is managing the boric acid corrosion control program through a review of the following evaluations:

(1)

  • New Boric Acid condition reports (CRs) from NRC walkdown o CR1253408 o CR1253409 o CR1253410 o CR1253412
  • Boric Acid Engineering Evaluations o CR1226002 o CR1226017 o CR1240440

71111.11B - Licensed Operator Requalification Program and Licensed Operator Performance

Licensed Operator Requalification Program (IP Section 03.04) (1 Sample)

An inspection was performed to assess the effectiveness of the facility licensee in implementing requalification requirements identified in 10 CFR Part 55, Operators Licenses. Each of the following inspection activities was conducted in accordance with IP

===71111.11, Licensed Operator Requalification Program and Licensed Operator Performance.

(1) Biennial Requalification Written Examinations

The inspectors evaluated the quality of the licensed operator biennial requalification written examination administered on January 20, 2023.

Annual Requalification Operating Tests

The inspectors evaluated the adequacy of the facility licensees annual requalification operating test.

Administration of an Annual Requalification Operating Test

The inspectors evaluated the effectiveness of the facility licensee in administering requalification operating tests required by 10 CFR 55.59(a)(2) and that the facility licensee is effectively evaluating their licensed operators for mastery of training objectives.

Requalification Examination Security

The inspectors evaluated the ability of the facility licensee to safeguard examination material, such that the examination is not compromised.

Remedial Training and Re-examinations

The inspectors evaluated the effectiveness of remedial training conducted by the licensee, and reviewed the adequacy of re-examinations for licensed operators who did not pass a required requalification examination.

Operator License Conditions

The inspectors evaluated the licensees program for ensuring that licensed operators meet the conditions of their licenses.

Control Room Simulator

The inspectors evaluated the adequacy of the facility licensees control room simulator in modeling the actual plant, and for meeting the requirements contained in 10 CFR 55.46.

71111.11Q - Licensed Operator Requalification Program and Licensed Operator Performance

Licensed Operator Performance in the Actual Plant/Main Control Room (IP Section 03.01) (1 Sample)

(1) The inspectors observed and evaluated licensed operator performance in the main control room during the planned shutdown of Unit 1 for RFO 1R30 on March 2, 2024.

Licensed Operator Requalification Training/Examinations (IP Section 03.02)===

Main article: IP 71111.11
(1) The inspectors observed and evaluated just-in-time training for a planned shutdown of Unit 1 for RFO 1R30 on February 29, 2024.
(2) The inspectors observed and evaluated just-in-time training for Unit 1 reactor startup from RFO 1R30 on March 27, 2024.

71111.12 - Maintenance Effectiveness

Maintenance Effectiveness (IP Section 03.01) (1 Sample)

The inspectors evaluated the effectiveness of maintenance to ensure the following structures, systems, and components (SSCs) remain capable of performing their intended function:

(1) Technical support center heating, ventilation, and air-conditioning system, on March 13, 2024

71111.13 - Maintenance Risk Assessments and Emergent Work Control

Risk Assessment and Management Sample (IP Section 03.01) (4 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) Unit 1 decreased inventory with 'B' reserve service station transformer out of service for maintenance, week of March 3, 2024
(2) Unit 1 'A' reactor coolant pump (RCP) lift and Unit 1 4160-volt 'H' bus outage, week of March 11, 2024
(3) Unit 1 'J' emergency diesel generator inoperability during undervoltage relay sequence timer out of service and subsequent technical specification retraction, Unit 1 'A' RCP structural deformation and casing defect evaluation, Unit 1 core onload, Unit 1 temporary reactor vessel cover removal, and yellow shutdown risk for spent fuel pit cooling during 'B' service water header outage, week of March 18, 2024
(4) Unit 1 'A' RCP reassembly emergent issues, week of March 25, 2024

71111.15 - Operability Determinations and Functionality Assessments

Operability Determination or Functionality Assessment (IP Section 03.01) (4 Samples)

The inspectors evaluated the licensee's justifications and actions associated with the following operability determinations and functionality assessments:

(1) CR1247436, Low Speed Increaser Oil Level on 2-CH-P-1B, on January 4, 2024
(2) CR1235686, PMT Not Performed and Retraction of Entry into TS 3.7.8, Conditions C and E for SW Spray Arrays, on February 16, 2024
(3) CR1248987, Received Annunciator 2K-E1 (RWST Hi Level) Well Below the Nominal Setpoint, on March 6, 2024
(4) CR1242003, 2-SI-71 Found Out of Position, on March 6, 2024

71111.20 - Refueling and Other Outage Activities

Refueling/Other Outage Sample (IP Section 03.01) (1 Partial)

(1) (Partial) The inspectors evaluated Unit 1 RFO 1R30 activities (Inspection Procedure

===71111.20, sections 03.01.a through 03.01.c), from March 3, 2024, to March 31, 2024.

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)===

Main article: IP 71111.20
(1) 1-PT-14.1, charging pump 1-CH-P-1A operability test, following pump discharge and service water check valve tests, on January 8, 2024
(2) Unit 1 'H' emergency diesel generator test following 15H11 directional overcurrent relay replacement under work order (WO) 59203387454, on March 17, 2024
(3) 1-RC-MOV-1595 loop stop valve stroke and diagnostic test following planned actuator and disc replacement under WO59203374819, on March 18, 2024
(4) 1-SW-MOV-102B as-left diagnostic test following planned actuator maintenance under WO59203403727, on March 22, 2024
(5) 1-SW-MOV-105A as-left diagnostic test following planned valve seat replacement under WO59203424713, on March 26, 2024
(6) 1-PT-61.3, containment type C test of 1-CC-TV-105A following valve maintenance under WO59203425959, on March 26, 2024

Surveillance Testing (IP Section 03.01) (6 Samples)

(1) 2-PT-32.6.4, Steamline 'B' Steam Pressure Protection Channel II, on January 24, 2024
(2) 2-PT-14.1, Charging Pump 2-CH-P-1A, on January 29, 2024
(3) 1-PT-31.2.1, Reactor Coolant System Temperature Instrumentation Calibration for Protection Channel I, on January 29, 2024
(4) 2-PT-57.1A, Emergency Core Cooling Subsystem - 'A' Low Head Safety Injection Pump Test, on January 30, 2024
(5) 1-PT-66.3, Containment Depressurization Actuation Testing, on March 4, 2024
(6) 1-PT-138.3B, Combined Charging Pump '1B' Head Curve Verification and HHSI Branch Flow Verification Using Smart Transmitters, on March 8, 2024

Inservice Testing (IST) (IP Section 03.01)

2-PT-14.3, Charging Pump 2-CH-P-1C, on January 29, 2024.

Containment Isolation Valve (CIV) Testing (IP Section 03.01) (1 Sample)

(1) 1-PT-61.3, Containment Type C Test [Penetration 44, air monitor sample containment isolation valve, 1-RM-TV-100B], on March 20,

RADIATION SAFETY

71124.01 - Radiological Hazard Assessment and Exposure Controls

Radiological Hazard Assessment (IP Section 03.01) (1 Sample)

(1) The inspectors evaluated how the licensee identifies the magnitude and extent of radiation levels and the concentrations and quantities of radioactive materials and how the licensee assesses radiological hazards.

Instructions to Workers (IP Section 03.02) (1 Sample)

(1) The inspectors evaluated how the licensee instructs workers on plant-related radiological hazards and the radiation protection requirements intended to protect workers from those hazards.

Contamination and Radioactive Material Control (IP Section 03.03) (3 Samples)

The inspectors observed/evaluated the following licensee processes for monitoring and controlling contamination and radioactive material:

(1) Inspectors observed workers exiting the unit 1 containment area.
(2) Inspectors observed workers monitoring and surveying dry active waste (DAW) out of the radiologically controlled area (RCA).
(3) Workers exiting the RCA during unit 1 refueling outage.

Radiological Hazards Control and Work Coverage (IP Section 03.04) (4 Samples)

The inspectors evaluated the licensee's control of radiological hazards for the following radiological work:

(1) Lift and removal of reactor coolant system (RCS) loop stop valve 1-RC-MOV-1595 for maintenance.
(2) RCP 1A impeller lift and shield plug installation.
(3) Cutting and machining of piping for chemical addition tank removal.
(4) Scaffold building activities inside the radiological controlled area related to unit 1 outage.

High Radiation Area and Very High Radiation Area Controls (IP Section 03.05) (4 Samples)

The inspectors evaluated licensee controls of the following high radiation areas (HRAs) and very high radiation areas (VHRAs):

(1) Unit 2 volume control tank locked high radiation area (LHRA).
(2) Demineralizer alley LHRA.
(3) RCP 1C LHRA.
(4) LHRA controls for RCP 1A impeller lift.

Radiation Worker Performance and Radiation Protection Technician Proficiency (IP Section 03.06) (1 Sample)

(1) The inspectors evaluated radiation worker and radiation protection technician performance as it pertains to radiation protection requirements.

71124.03 - In-Plant Airborne Radioactivity Control and Mitigation

Permanent Ventilation Systems (IP Section 03.01) (2 Samples)

The inspectors evaluated the configuration of the following permanently installed ventilation systems:

(1) ECCS Pump Room Train A Exhaust Air Cleanup System (ECCS PREACS) [0-PT-77.14A which includes In-Place HEPA penetration/bypass, flow rate test, and Charcoal] 2/17/2021 and 1/31/2023. Laboratory Charcoal analysis completed 06/17/2022 and 08/18/2023 ECCS Pump Room Train B Exhaust Air Cleanup System (ECCS PREACS) [0-PT-77.14B which includes HEPA penetration/bypass, flow rate test, and Charcoal] 11/03/2021 and 7/30/2023. Laboratory Charcoal analysis completed 06/20/2022 and 06/04/2023
(2) Main Control Room Train A [1-PT-76.12A which includes In-Place HEPA penetration/bypass, and flow rate test 06/15/2021 and 11/30/2022. Laboratory Charcoal analysis completed 06/23/2021 and 12/08/2022 Main Control Room Train B [1-PT-76.12B which includes HEPA penetration/bypass, and flow rate test] 09/30/2021 and 03/07/2023. Laboratory Charcoal analysis completed 04/14/2019 and 10/05/2022

Temporary Ventilation Systems (IP Section 03.02) (2 Samples)

The inspectors evaluated the configuration of the following temporary ventilation systems:

(1) HEPA Unit 29 setup for work on valve 1-RC-MOV-1595, RCS Loop Stop Valve
(2) HEPA Unit 2046 setup for work on 1A charging pump

Use of Respiratory Protection Devices (IP Section 03.03) (1 Sample)

(1) The inspectors evaluated the licensees use of respiratory protection devices.

Self-Contained Breathing Apparatus for Emergency Use (IP Section 03.04) (1 Sample)

(1) The inspectors evaluated the licensees use and maintenance of self-contained breathing apparatuses.

71124.04 - Occupational Dose Assessment

Source Term Characterization (IP Section 03.01) (1 Sample)

(1) The inspectors evaluated licensee performance as it pertains to radioactive source term characterization.

External Dosimetry (IP Section 03.02) (1 Sample)

(1) The inspectors evaluated how the licensee processes, stores, and uses external dosimetry.

Internal Dosimetry (IP Section 03.03) (2 Samples)

The inspectors evaluated the following internal dose assessments:

(1) Random whole body counts of five workers wearing respiratory protection during the spring 2024 Unit 1 outage (3/25/2024 and 3/26/2024)
(2) Three for cause (facial contamination) whole body count records completed by the licensee between March 1, 2022, and March 1, 2024, were reviewed with no discrepancies identified.

Special Dosimetric Situations (IP Section 03.04) (2 Samples)

The inspectors evaluated the following special dosimetric situations:

(1) Multi-Badge Dosimetry documentation for a worker performing RCP repair activities during the fall 2023 Unit 2 outage. (ID # 28571, RWP 23-2247)
(2) Multi-Badge Dosimetry documentation for a worker performing RCP repair activities during the fall 2023 Unit 2 outage. (ID # 82039, RWP 23-2247)

71124.05 - Radiation Monitoring Instrumentation

Walkdowns and Observations (IP Section 03.01) (6 Samples)

The inspectors evaluated the following radiation detection instrumentation during plant walkdowns:

(1) Installed and temporary (AMP-100, DRM, etc.) area radiation monitors located in various locations in the auxiliary and containment building.
(2) Personnel contamination monitors, portal monitors, and small article monitors located at the radiologically controlled area exit.
(3) Hand and foot monitors located at the Unit 2 containment exit point.
(4) Portable friskers located in various locations in the auxiliary building.
(5) AMS-4 and iCAM continuous air monitors located in various areas in the auxiliary building.
(6) Portable survey instruments (Teletector, RO-20, Radeye, etc.) stored in response checked cabinet and available for issue/use.

Calibration and Testing Program (IP Section 03.02) (15 Samples)

The inspectors evaluated the calibration and testing of the following radiation detection instruments:

(1) Mirion iCAM (continuous air monitor), ID # 22009517 (Calibration date: 10/18/2023)
(2) Eberline Radeye G, ID # 30097 (Calibration date: 03/06/2023 and 03/02/2024)
(3) Eberline Radeye G, ID # 30333 (Calibration date: 02/01/2022 and 08/29/2023)
(4) Eberline Radeye GX, ID # 10994 (Calibration date: 02/16/2023 and 02/23/2024)
(5) Eberline RO-20 (Ion chamber), ID# 5429 (Calibration date: 08/24/2022 and 08/08/2023)
(6) Eberline RO-20 (Ion chamber), ID# 183AA (Calibration date: 10/06/2022 and 08/08/2023)
(7) Mirion Telepole, ID# 6607-041 (Calibration date: 03/09/2023 and 02/15/2024)
(8) Ludlum Model 3030 Scaler, ID# 328901 (Calibration date: 06/08/2022 and 07/11/2023)
(9) Ludlum Model 2000 Scaler, ID# 310624 (Calibration date: 07/12/2023)
(10) Eberline AMS-4, ID# 1030 (Calibration date: 10/24/2022 and 10/04/2023)
(11) Eberline SAM-11 (small article monitor), ID# 476 (Calibration date: 08/28/2023)
(12) Mirion GEM-5 (portal monitor), ID# 1810-289-GE0500G (Calibration date: 08/02/2022 and 07/26/2023)
(13) Eberline PM-7 (portal monitor), ID# 673 (Calibration date: 07/18/2022 and 07/13/2023)
(14) Eberline PCM-2 (personnel contamination monitor), ID# 568 (Calibration date:

03/20/2022 and 03/23/2023)

(15) Mirion Sirius 5PAB (hand & foot monitor), ID# 1508-117-SR05PAB (Calibration date:

08/17/2022 and 05/31/2023)

Effluent Monitoring Calibration and Testing Program Sample (IP Section 03.03) (3 Samples)

The inspectors evaluated the calibration and maintenance of the following radioactive effluent monitoring and measurement instrumentation:

(1) Unit 2, Vent Stack A Normal and High Range Effluent Radiation Monitor, VG-RM-179 (Calibration Date: 07/16/2021 and 01/13/2023)
(2) Unit 2, Vent Stack B Normal and High Range Effluent Radiation Monitor, VG-RM-180 (Calibration Date: 07/01/2021 and 11/30/2022)
(3) Liquid Waste Clarifier Radiation Monitors, 1-RM-LW-110 and 1-RM-LW-111 (Calibration Date: 12/28/2022, 08/23/2023, and 01/12/2024)

OTHER ACTIVITIES - BASELINE

===71151 - Performance Indicator Verification

The inspectors verified licensee performance indicators submittals listed below:

IE01: Unplanned Scrams per 7000 Critical Hours Sample (IP Section 02.01)===

Main article: IP 71151
(1) Unit 1: January 1, 2023, to December 31, 2023
(2) Unit 2: January 1, 2023, to December 31, 2023

IE03: Unplanned Power Changes per 7000 Critical Hours Sample (IP Section 02.02) (2 Samples)

(1) Unit 1: January 1, 2023, to December 31, 2023
(2) Unit 2: January 1, 2023, to December 31, 2023

IE04: Unplanned Scrams with Complications (USwC) Sample (IP Section 02.03) (2 Samples)

(1) Unit 1: January 1, 2023, to December 31, 2023
(2) Unit 2: January 1, 2023, to December 31, 2023

BI01: Reactor Coolant System (RCS) Specific Activity Sample (IP Section 02.10) (2 Samples)

(1) Unit 1: January 1, 2023, to December 31, 2023
(2) Unit 2: January 1, 2023, to December 31, 2023

BI02: RCS Leak Rate Sample (IP Section 02.11) (2 Samples)

(1) Unit 1: January 1, 2023, to December 31, 2023
(2) Unit 2: January 1, 2023, to December 31, 2023

OR01: Occupational Exposure Control Effectiveness Sample (IP Section 02.15) (1 Sample)

(1) September 1, 2023, through February 29, 2024

PR01: Radiological Effluent Technical Specifications/Offsite Dose Calculation Manual Radiological Effluent Occurrences (RETS/ODCM) Radiological Effluent Occurrences Sample (IP Section 02.16) (1 Sample)

(1) September 1, 2023, through February 29, 2024

71153 - Follow Up of Events and Notices of Enforcement Discretion Event Follow up (IP Section 03.01)

Main article: IP 71153
(1) CR1250633, Suspect Spillway Septic Drainage System Is Degraded, on February 8, 2024, and CR125098, Process Vent Alarm During 1-CH-FL-4A Fill on February 14, 2024

Event Report (IP Section 03.02) (1 Sample)

The inspectors evaluated the following licensee event reports (LERs):

(1) LER 05000339/2023-001-00, North Anna Power Station, Unit 2, Reactor Coolant Pressure Boundary Leak Due to Poor Weld Workmanship (ADAMS Accession No.

ML24012A145). The inspection conclusions associated with this LER are documented in this report under the Inspection Results Section

INSPECTION RESULTS

Failure to Develop or Implement Preventive Maintenance Strategy in Accordance with Procedures Cornerstone Significance Cross-Cutting Report Aspect Section Mitigating Green None (NPP) 71152A Systems FIN 05000338,05000339/2024001-01 Open/Closed A self-revealed Green finding was identified for the licensee's failure to develop adequate preventive maintenance strategies for the 'A' and 'B' station blackout (SBO) diesel generator (DG) radiator fans in accordance with Dominion Procedure, ER-AA-PRS-1010, Preventive Maintenance Task Basis and Maintenance Strategy, Revision 16.

Description:

The North Anna SBO DG system is relied on to mitigate a loss of all onsite and offsite alternating current (AC) power. During operation, two radiator fans blow cool air over their respective radiators to remove heat from the diesel. Both radiator fans are required to be functional and in service during diesel operation. Without either fan, the SBO may be subject to increased jacket coolant and lubricating oil temperatures.

On February 5, 2023, approximately an hour into a post-maintenance test (PMT) of the SBO DG, an emergent shutdown of the SBO DG was performed due to a field report and indications of high lubricating oil and jacket coolant water temperatures. Investigation and troubleshooting determined the supply breaker to the 'B' SBO DG radiator fan tripped. The licensee's subsequent evaluation and vendor analysis (CA11455419) concluded that the 'B' radiator fan motor experienced "grounding [of all three phases]," and noted the motors internals were significantly degraded and rusted throughout its interior due to excess water inleakage. Engineering logs further stated that "the bearings in 0-BCW-F-1B were unsat during motor investigation." The 'B' SBO DG radiator fan motor was subsequently replaced, tested, and the SBO DG restored to an available and functional status on February 8, 2023.

Prior to the event, the SBO DG's last successful run was on November 16, 2022.

On July 24, 2023, a routine surveillance test of the SBO DG was suspended when an operator noted a loud abnormal noise coming from the A SBO radiator fan. This noise was initially attributed to the 'A' radiator fan having degraded motor bearings. The 'A' radiator fan motor was subsequently replaced on July 24, 2023. During the replacement, water was observed leaking from the motor and the licensee initially concluded that "rainwater intrusion resulted in bearing failure of 0-BCW-F-1A (SBO radiator fan)." An analysis and uncoupled run of the 'A' radiator fan motor later revealed that while the motor was degraded and previously documented as unsatisfactory during an electrical inspection for freedom of rotation, internal rubbing, binding, and noise in WO59203407282, the motor was able to perform its function.

During a subsequent run of the SBO DG on August 8, 2023, loud audible noises were again observed emanating from the 'A' SBO radiator fan. It was later identified that the 'A' SBO radiator fan blower bearings were degraded. The bearings had minor spalling on the bearing races and surface pitting on the roller elements due to lack of lubrication. In this case, the licensee also concluded that the 'A' SBO radiator fan would have been able to support the SBO diesels 4-hour mission time.

In NRC Inspection Report 050000338/050000339/2023-001, the inspectors opened unresolved item (URI) 05000338,05000339/2023003-01, "Moisture Intrusion Resulting in Station Blackout (SBO) Radiator Fan Motor Issues," to determine if a performance deficiency existed for either of the 'A' or 'B' radiator fan events. In response to the URI, the licensee completed engineering evaluation CA12203651, which clarified differences between each event and captured additional corrective actions taken by the licensee.

The inspectors reviewed the evaluation along with supplemental information and noted that despite an extensive list of vendor and Electric Power Research Institute recommendations, no preventive maintenance (PM) activities were being performed on the SBO radiator fan motors or blowers to ensure reliability, such as: motor cleaning and being kept free of water and/or debris; oil analyses; blower bearing and radiator fan motor lubrication; insulation resistance testing; acoustic monitoring; vibration monitoring; motor performance testing, operator/engineering walkdowns; or refurbishments. In fact, WO 59203407282 noted the 'A' radiator fan motor bearings had no lubrication schedule. The inspectors also found that a previously adopted maintenance strategy to perform bridge and megger testing of the radiator fan motors was eliminated in 1998 under engineering evaluation CMP 98-007. This evaluation stated the bridge and megger testing PM strategy was to be replaced with a motor lubrication/greasing PM strategy. However, no PMs for lubricating the SBO radiator fan motors were created and while the radiator fan blowers had greasing PMs, the inspectors found that the licensee had not performed the PM in several years. Based on these findings, the inspectors concluded that the degraded conditions of the A and B SBO radiator fans was within the licensee's ability to foresee and correct.

As described in Dominion Procedure ER-AA-PRS-1010, Development and use of PM templates is an important aspect of equipment reliability. PM templates govern which maintenance tasks are required and frequency at which they are performed. Task type and frequency are dependent on a component's criticality (importance to safety and/or production), duty cycle, and service condition determined in accordance with ER-AA-PRS-1003... Crit 1 is synonymous with 'Critical' and 'Crit 2' is synonymous with 'Important Non-critical' criticality designators."

Because the SBO radiator fan components are considered critical 1, low service condition, mild environment components, the inspectors noted the licensee's failure to have PM strategies for these components was contrary to ER-AA-PRS-1010. Specifically, ER-AA-PRS-1010, 3.2.1, requires the licensee develop maintenance strategies for station equipment classified as Critical. As a result, the licensee did not detect or identify motor and blower degradation, prior to the 'B' radiator fan motor failure on February 5, 2023, 'A' radiator fan motor degradation on July 24, 2024, or 'A' radiator fan blower degradation on August 8, 2023.

Corrective Actions: In response to the events, the licensee replaced both A and B radiator fan motors, the 'A' radiator fan blower bearings, and performed satisfactory tests of the SBO DG. Interim corrective actions included installation of covers to keep water from entering the motors. Additionally, the licensee developed recurrent PM tasks that includes a 20-year radiator fan motor replacement, annual motor bearing lubrication, triennial fan bearing lubrication, 5-year t-slot plug replacement, and a 20-year fan bearing replacement.

Corrective Action References: CR1024867, CR1218825, CR1233878, CR1233999, CR1234896, CR1234897, CA3024511, CA11455419

Performance Assessment:

Performance Deficiency: The inspectors determined the licensee's failure to develop and implement an adequate PM strategy was foreseeable, preventable, and was a performance deficiency.

Screening: The inspectors determined the performance deficiency was more than minor because it was associated with the Equipment Performance attribute of the Mitigating Systems cornerstone and adversely affected the cornerstone objective to ensure the availability, reliability, and capability of systems that respond to initiating events to prevent undesirable consequences. Specifically, increased jacket water and lubricating oil temperatures from a 'B' radiator fan motor failure resulted in the SBO DG being declared nonfunctional. Additionally, abnormal noises from the 'A' radiator fan motor and blower resulted in emergent maintenance on the SBO DG on two separate occasions.

Significance: The inspectors assessed the significance of the finding using IMC 0609 Appendix A, The Significance Determination Process (SDP) for Findings At-Power. The inspectors reviewed the Mitigating Systems Screening Questions and answered "yes" to question 5, which determined a detailed risk evaluation by the regional senior reactor analyst (SRA) was warranted. The SRA modeled the conditions using North Anna SPAR model version 8.82, dated 9/26/23, and SAPHIRE 8 version 8.2.9. The SRA determined that the degraded A fan did not result in a loss of function for the SBO DG thus this condition would screen to Green. For the B fan failure, the SRA considered an exposure period (T) to be from November 16, 2022, to February 8, 2023, or 82 days. Since the equipment was in standby and the environmental conditions which caused the motor to fail to start upon demand were present throughout the 82 days, then per the RASP Manual, Volume 1, Version 2.0.2, Section 2.4, the exposure time is T/2 or 41 days. The B fan failure was conservatively modeled by setting EPS-DGN-FR-DGAAC (Alternate AC Diesel Generator Fails to Run) to 1.0 with no adjustment to the Common Cause Failure probabilities because the SBO diesel is the only DG with external cooling fans subject to the failure mechanism. The SRA also credited FLEX equipment and FLEX implementation strategies. This is conservative and bounding since the SBO DG is assumed to fail at the same time as the support system, when in reality, the SBO DG would be able to perform its PRA function for a few hours without adequate cooling (as demonstrated during the surveillance). The dominant accident sequence is a weather-related loss of offsite power event, with a failure to run of both the 1H and 1J emergency diesel generators (EDGs), failure to recover an EDG or offsite power in 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, and a failure of the FLEX reactor coolant make-up pump. The resultant change in core damage frequency would be less than 1 E-6 events per year; therefore, the finding is of very low safety significance (Green).

Cross-Cutting Aspect: Not Present Performance. No cross-cutting aspect was assigned to this finding because the inspectors determined the finding did not reflect present licensee performance.

Enforcement:

Inspectors did not identify a violation of regulatory requirements associated with this finding.

The disposition of this finding closes URI: 05000338,05000339/2023003-01.

Failure to Perform Work In accordance with Procedures Results in Reactor Coolant System Pressure Boundary Weld Leak Cornerstone Significance Cross-Cutting Report Aspect Section Barrier Integrity Green None (NPP) 71153 NCV 05000339/2024001-02 Open/Closed A self-revealed Green finding and associated non-cited violation (NCV) of 10 CFR Part 50, Appendix B, Criterion IX, Control of Special Processes, was identified when a deficient weld in reactor coolant system (RCS) piping failed and resulted in pressure boundary leakage from a Unit 2 pressurizer instrument line.

Description:

On September 11, 2023, dry boric acid crystals were discovered on 1/2-inch stainless steel tubing (ICN9) for the Unit 2 pressurizer level transmitter instrument low side isolation valve line, 2-RC-ICV-3162. The tubing, which was fabricated in 1998, is part of the reactor coolant pressure boundary and is designated as ASME Code Class 1. The licensee determined that the source of the boric acid crystals on the tubing was a through-wall leak from socket weld no.14. As a result of this determination, the licensee made an 8-hour emergency notification report to the NRC under 10 CFR 50.72(b)(3)(ii)(A) for a seriously degraded principal safety barrier. The piping was subsequently repaired in accordance with ASME Section XI requirements, and the failed weld was sent off for metallurgical analysis to determine the cause of the failure.

In an engineering evaluation (CA12170863), dated November 4, 2023, the licensee concluded that the direct cause of the weld failure was "inadequate welding process control by the individual welder which resulted in a significant lack of fusion defect." During visual inspection of the section of tubing sent off for metallurgical analysis, the licensee identified evidence of poor workmanship on both the inside and outside surfaces of the failed socket weld, melt-through (penetrated weld metal that extends beyond the base metal), suck-back (internal concavity), multiple arc strikes, and excessive grinding. Destructive examination performed on the failed socket weld identified lack of fusion extending from the root of the weld to the outer edge of the weld. In addition, laboratory analysis of the failed weld concluded that the defect was not caused by service induced degradation. Based on these findings, the licensee's evaluation indicated that the weld quality issues should have been addressed during fabrication and that the condition could have been identified at that time and corrected.

Corrective Actions: The licensee repaired the defected socket welded coupling. Additionally, the licensee cutout, welded, and replaced a similar coupling downstream of the affected area in accordance with the 2013 ASME Boiler and Pressure Vessel Code,Section XI, Rules for Inservice Inspection of Nuclear Power Plant Components. Nondestructive surface examinations and external leakage checks were performed on the replacement socket welds.

The licensee also created work orders to inspect and repair similarly sized tubing socket welds fabricated during the same timeframe under design change packages (DCP)96-122 and DCP 96-130 during future refueling outages for each unit.

Corrective Action References: CA12170863, CA12252067, CA12252069

Performance Assessment:

Performance Deficiency: The inspectors determined that the licensee's failure to control welding on the 1/2-inch stainless steel tubing (ICN9) for the Unit 2 pressurizer level instrument line was a performance deficiency.

Screening: The inspectors determined the performance deficiency was more than minor because it was associated with the Human Performance attribute of the Barrier Integrity cornerstone and adversely affected the cornerstone objective to provide reasonable assurance that physical design barriers protect the public from radionuclide releases caused by accidents or events. Specifically, the licensees failure to control welding in accordance with its procedures reduced the expected design life of the weld and resulted in a through-wall leak path in the tubing for the Unit 2 pressurizer instrument line.

Significance: The inspectors assessed the significance of the finding using IMC 0609 Appendix A, The Significance Determination Process (SDP) for Findings At-Power. The IMC directs the inspectors to use the Initiating Events Screening questions when the finding pertains to RCS boundary issues such as leaks. Using the Initiating Events Screening Questions found in Exhibit 1, Section A, Loss of Coolant Accident (LOCA) Initiators, the finding screened as Green, because the finding did not result in exceeding the RCS leak rate for a small LOCA (leakage in excess of normal makeup), nor could have likely affected other systems used to mitigate a LOCA.

Cross-Cutting Aspect: Not Present Performance. No cross-cutting aspect was assigned to this finding because the inspectors determined the finding did not reflect present licensee performance. Specifically, the performance deficiency was introduced in 1998 during implementation of a design modification on the Unit 2 pressurizer instrument line.

Enforcement:

Violation: 10 CFR Part 50, Appendix B, Criterion IX, Control of Special Processes, requires in part that, "Measures shall be established to assure that special processes, including welding, heat treating, and nondestructive testing, are controlled and accomplished by qualified personnel using qualified procedures in accordance with applicable codes, standards, or other special requirements.

Contrary to the above, on April 15, 1998, the licensee failed to adequately control the welding performed on the 1/2-inch stainless steel tubing located on line number ICN9, which resulted in the failure of weld no.14 inservice. Specifically, inadequate control of the welding process resulted in the formation of a lack of fusion defect between the weld and base metal. The lack of fusion defect was not identified prior to placing the component in service and, over time, it created a pathway for pressure boundary leakage.

Enforcement Action: This violation is being treated as a non-cited violation, consistent with Section 2.3.2 of the Enforcement Policy.

EXIT MEETINGS AND DEBRIEFS

The inspectors verified no proprietary information was retained or documented in this report.

  • On April 18, 2024, the inspectors presented the integrated inspection results to Lisa Hilbert, Site Vice President, and other members of the licensee staff.
  • On January 25, 2024, the inspectors presented the licensed operator biennial requalification inspection results to Jim Jenkins, Plant Manager, and other members of the licensee staff.
  • On March 14, 2024, the inspectors presented the inservice inspection results to Lisa Hilbert, Site Vice President, and other members of the licensee staff.
  • On March 28, 2024, the inspectors presented the radiation safety inspection results to Lisa Hilbert, Site Vice President, and other members of the licensee staff.

THIRD PARTY REVIEWS

The inspectors did not review any third-party reports during the inspection period.

DOCUMENTS REVIEWED

Inspection Type Designation Description or Title Revision or

Procedure Date

71111.01 Procedures 0-AP-41 Severe Weather Conditions 82

0-GOP-9.11 Shift Technical Advisor 19

71124.03 ALARA Plans24-008 TEDE ALARA Review for RWP 24-3247, 02/26/2024

24-010 TEDE ALARA Review for RWP 24-3251, 02/27/2024

Disassemble/Reassemble Reactor Head

24-014 TEDE ALARA Review for RWP 24-3269, Disassemble, 02/26/2024

Replace Guides and Disc, and Re-assemble 1-RC-MOV-

1595

Corrective Action Condition Reports Reviewed during the course of the Various

Documents inspection: CR1194087, CR1204218, CR1238032, and CR

254960.

Miscellaneous Grade D Breathing Air Sample Analysis Results for Breathing 03/14/2023

Air Compressor Numbers: 2-SA-109, 2-SA-111, and the

Paint Shop

Grade D Breathing Air Sample Analysis Results for Breathing 08/29/2023

Air Compressor Numbers: 2-SA-109, 2-SA-111, and the

Paint Shop

O-PT-114 Emergency Kit Respirator Inspections [Monthly or quarterly Various

inspections for November and December 2023 and January

24]

RP-AA-163, Radiological Use SCBA Inspection Record [Monthly Various

inspections for November and December 2023 and January

24]

Self-Assessments PA9212199 Radiological Respiratory Protection Program for the period 08/30/2022

August 2019 - July 2022

71124.04 Calibration NVLAP LAB Radiation Detection Company NVLAP Certificate of Various

Records CODE: 100512-0 Accreditation, 03/06/2023 thru 12/31/2024

NVLAP LAB Mirion Technologies (GDS), Inc NVLAP Certificate of Various

CODE: 100555-0 Accreditation, 10/01/2021 thru 06/30/2024

Corrective Action Condition Reports Reviewed during the course of the Various

Documents inspection: CR1192524, CR1217883, CR1234542, and

CR1244421

Inspection Type Designation Description or Title Revision or

Procedure Date

Miscellaneous Whole Body Counter (WBC) Counting Libraries (Inhalation, 03/26/2024

Mixed Gamma, Medical, and QA)

Personal Contamination Event (PCE) Logs from 03/01/2022 Various

through 03/25/2024

Annual Dosimetry Vendor Confirmatory Measurement 12/14/2023

Testing - Mirion 2023 [RP-AA-150, TLD Performance

Testing)

Annual Dosimetry Vendor Confirmatory Measurement 12/14/2023

Testing - Radiation Detection Company 2023 [RP-AA-150,

TLD Performance Testing)

Routine Facility Characterization of Alpha Source Term - Various

North Anna April 2012 to August 2022, February 2022 to

November 2022, and September 2022 to January 2024.

Dosimetry and Instrumentation Neutron Correction Factors 06/24/2021

Procedures RP-AA-150 TLD Performance Testing Revision 7

Radiation Restricted and Controlled Area Dose Evaluation for the Various

Surveys period 01/01/2022 through 12/31/2023 [General Plant Area

Monitoring TLDs]

71124.05 Calibration SN 8256 JL Shepherd Model 89-400 Calibrator 07/06/2022

Records SN 8282 JL Shepherd Model 89-400 Calibrator 07/06/2022

Corrective Action Condition Reports Reviewed during the course of the Various

Documents inspection: CR1194974, CR1233479, CR1238139,

CR1239420, CR1205772, CR1205775, CR1249654,

CR1250665, and CR1246461

Engineering Radiation Monitoring System Health Report 05/20/2023

Evaluations 07797.16-UR- Engineering Calculation - Radiation Monitoring Calculation, Revision 2

(B)-043 Ventilation Radiation Monitors

ET-N009-0046 Evaluation of Calibration Source for the Area Radiation 08/25/2010

Monitoring System

Miscellaneous Radiochemistry Cross Check Program Results from 2022 Various

and 2023 [Laboratory Intercomparison Program including

Whole Body counters and Environmental Laboratory Gamma

Spec Systems]

HPTB-2112 Radiological Instrumentation Program: Technical Bases Revision 0

Inspection Type Designation Description or Title Revision or

Procedure Date

HPTB-2115 Radioactive Contamination Control Program: Technical Revision 0

Bases

Procedures North Anna Power Station Technical Requirements Manual 01/23/2024

0-GIP-4.0 RMS Calibration Sources Revisions

15, 16, and

VPAP-2103N Offsite Dose Calculation Manual (North Anna) Revision 30

Self-Assessments PA9212223 Review of Radiological Instrumentation Control Program 2nd 11/22/2022

quarter 2020 to 4th quarter 2022

Work Orders W/O Containment Gaseous Radiation Monitor Channel (RM-RMS- 03/02/2021

203294063 260) Calibration

W/O Containment Radiation Monitoring Instrument Calibration 03/27/2022

203322724 (RMS-266) [2-RM-RMS-266]

W/O Containment Particulate Radiation Monitor Channel (RM- 06/10/2022

203326474 RMS-259) Calibration

W/O Containment Gaseous Radiation Monitor Channel (RM-RMS- 10/25/2022

203354650 260) Calibration

W/O Containment Radiation Monitoring Instrument Calibration 09/27/2023

203385151 (RMS-265) 2-RM-RMS-265

W/O Containment Radiation Monitoring Instrument Calibration 09/27/2023

203385249 (RMS-266) [2-RM-RMS-266]

W/O Containment Particulate Radiation Monitor Channel (RM- 12/13/2023

203389874 RMS-259) Calibration

Work Order Containment Radiation Monitoring Instrument Calibration 03/27/2022

(W/O) (RMS-265) 2-RM-RMS-265

203322809

71151 Calculations 24-AGR-01 Abnormal Gaseous Release [Process Vent Release on 02/21/2024

2/14/2024]

Corrective Action Condition Reports Reviewed during the course of the Various

Documents inspection: CR1208655, CR1243150, CR1240861,

CR1243806, CR1243839, CR1245034, CR1246026,

CR1248515, and CR1250938

Miscellaneous G-20240214-053- Radioactive Gaseous Release Permit (AGR-24-001) 02/21/2024

B

2

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