IR 05000338/2024004
| ML25038A022 | |
| Person / Time | |
|---|---|
| Site: | North Anna  (NPF-004, NPF-007) |
| Issue date: | 02/12/2025 |
| From: | James Baptist NRC/RGN-II/DORS/PB4 |
| To: | Carr E Dominion Energy Co |
| References | |
| IR 2024004 | |
| Download: ML25038A022 (1) | |
Text
SUBJECT:
NORTH ANNA POWER STATION - UNITS 1 AND 2 - INTEGRATED INSPECTION REPORT 05000338/2024004 AND 05000339/2024004
Dear Eric Carr:
On December 31, 2024, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection at North Anna Power Station - Units 1 and 2. On January 16, 2025, 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.
No findings or violations of more than minor significance were identified during this inspection.
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, James B. Baptist, Chief Projects Branch 4 Division of Operating Reactor Safety Docket Nos. 05000338 and 05000339 License Nos. NPF-4 and NPF-7
Enclosure:
As stated
Inspection Report
Docket Numbers:
05000338 and 05000339
License Numbers:
Report Numbers:
05000338/2024004 and 05000339/2024004
Enterprise Identifier:
I-2024-004-0018
Licensee:
Dominion Energy Corporation
Facility:
North Anna Power Station - Units 1 and 2
Location:
Mineral, VA
Inspection Dates:
October 01, 2024, to December 31, 2024
Inspectors:
K. Carrington, Senior Resident Inspector
D. Turpin, Resident Inspector
M. Donithan, Senior Operations Engineer
Approved By:
James B. Baptist, Chief
Projects Branch 4
Division of Operating Reactor Safety
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
No findings or violations of more than minor significance were identified.
Additional Tracking Items
None.
PLANT STATUS
Unit 1 operated at or near rated thermal power for the entire inspection period.
Unit 2 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 DProperty "Inspection Manual Chapter" (as page type) with input value "NRC Inspection Manual 2515,</br></br>Appendix D" contains invalid characters or is incomplete and therefore can cause unexpected results during a query or annotation process., 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:
Unit 1 refueling water storage tank, and Unit 2 refueling water storage tank, on
November 25, 2024.
71111.04 - Equipment Alignment
Partial Walkdown Sample (IP Section 03.01) (1 Sample)
The inspectors evaluated system configurations during partial walkdowns of the following
systems/trains:
(1)
Unit 2 'H' emergency diesel generator (2H EDG) system prior to 2H EDG fast start
quarterly surveillance, on December 31, 2024.
71111.05 - Fire Protection
Fire Area Walkdown and Inspection Sample (IP Section 03.01) (4 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 Zone 10A, fuel oil pump house room A, on December 20, 2024
(2)
Fire Zone 10B, fuel oil pump house room B, on December 20, 2024
(3)
Fire Zone 10C, fuel oil pump house motor control center, on December 20, 2024
(4)
Fire Area, 9A-1, Unit 1 emergency diesel generator 1J room, on December 27, 2024
71111.06 - Flood Protection Measures
Flooding Sample (IP Section 03.01) (1 Sample)
(1)
The inspectors evaluated external flooding mitigation protections in the:
2MH03 manhole, on December 9, 2024
71111.11A - Licensed Operator Requalification Program and Licensed Operator Performance
Requalification Examination Results (IP Section 03.03) (1 Sample)
The licensee completed the annual requalification operating examinations required to be
administered to all licensed operators in accordance with Title 10 of the Code of Federal
Regulations 55.59(a)(2), "Requalification Requirements," of the NRC's "Operator's
Licenses." The inspector performed an in-office review of the overall pass/fail results of the
individual operating examinations, and the crew simulator operating examinations in
accordance with Inspection Procedure (IP) 71111.11, "Licensed Operator Requalification
Program and Licensed Operator Performance." These results were compared to the
thresholds established in Section 3.03, "Requalification Examination Results," of IP 71111.11.
(1)
The inspectors reviewed and evaluated the licensed operator examination failure
rates for the requalification annual operating exam completed on February 2, 2024.
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 Unit 1, 'B' main feedwater pump uncoupled runs, on November 6-
7, 2024, and troubleshooting of Unit 1, 'A' motor generator (MG) set, on December
13, 2024.
71111.12 - Maintenance Effectiveness
Maintenance Effectiveness (IP Section 03.01) (3 Samples)
The inspectors evaluated the effectiveness of maintenance to ensure the following
structures, systems, and components (SSCs) remain capable of performing their intended
function:
(1)
the North Anna spillway emergency diesel generator system (CR1258873,
CR1255172, CR1245845, CR1260353), on October 17, 2024
(2)
Unit 1 and Unit 2 shared component cooling water system, on October 22, 2024
(3)
2-CH-MOV-2350, emergency boration valve and 2-CH-158 relief line leak
(CR1264744, CA12781370), on November 29, 2024
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)
Unit 1 and Unit 2 increased risk associated with emergency busses 2H and 2J
manual transfer to alternate power supplies, 500 KV bus No. 1 planned maintenance,
and Unit 2 safeguards exhaust fan emergent maintenance, on October 1, 2024
(2)
Unit 1 increased risk associated with Unit 1 'H' emergency diesel generator (EDG)
emergent troubleshooting following test failure, Unit 1 'C' charging pump planned
maintenance, and Unit 1 'C' main control room (MCR) chiller piping planned
maintenance, the week of October 10, 2024
(3)
Unit 1 increased risk associated with emergent maintenance on the following
components/systems-Unit 1 'A' MG set due to breaker tripping, Unit 1, 1-CN-PT-
150B, 'B' MFW pump suction pressure transmitter following failure, and Unit 2, 2-CH-
P-1B, 'B' charging pump following pump shaft contact with coupling guard during
testing, the week of December 9, 2024
71111.15 - Operability Determinations and Functionality Assessments
Operability Determination or Functionality Assessment (IP Section 03.01) (6 Samples)
The inspectors evaluated the licensee's justifications and actions associated with the
following operability determinations and functionality assessments:
(1)
CR1264021, During 1-PT-36.1A Relay K602 Failed to Latch when the Plunger was
Depressed, on October 18, 2024
(2)
CR1272799, 1-BD-TV-100D, 'B' SG Blowdown Inside Trip Valve, Failed to Close in
the Required Time Per 1-PT-213.1, on October 22, 2024
(3)
CR1252456, Improper Thread Engagement Identified on Pump Support, on
November 20, 2024
(4)
CR1271640, No Remote Speed Control of 1H EDG from Control Room, on
November 21, 2024
(5)
CR1278459, 2-CH-P-1B Failed 2-PT-14.2 Due to Head Curve Data Being Unsat, on
December 16, 2024
(6)
CR1273480, 2-SW-MOV-223B Failed Time Stroke, on December 23, 2024
71111.18 - Plant Modifications
Temporary Modifications and/or Permanent Modifications (IP Section 03.01 and/or 03.02) (1
Sample)
The inspectors evaluated the following temporary or permanent modifications:
(1)
Design Changes, NA-19-00032 and NA-19-00033, Swing Power Supply for
MCR/ESGR Chiller 1-HV-E-4C and 2-HV-E-4C, on October 18, 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) (6 Samples)
(1)
Unit 2 'A' service water pump breaker PMT following maintenance under work order
(WO) 59203449273, on October 1, 2024
(2)
1-PT-82.2A, 1H Diesel Generator Test (Simulated Loss of Off-site Power), following
speed setting adjustment, on October 10, 2024
(3)
Unit 1 'C' Charging Pump PMT following maintenance under WOs 59203352115,
59102916176, 59203402483, and 59203442776, on October 12, 2024
(4)
Unit 1 'J' EDG standby lube oil pump PMT following contactor replacement under
WO59203450105, on October 23, 2024
(5)
Diesel driven fire pump PMT following engine replacement under WO59203449565,
on October 24, 2024
(6)
Unit 2 'B' charging pump PMT following seal replacement under WO59102803499, on
December 12, 2024
Surveillance Testing (IP Section 03.01) (2 Samples)
(1)
2-PT-74.2A, Component Cooling Pump 2-CC-P-1A Test, on October 3, 2024
(2)
1-PT-57.1A, Emergency Core Cooling Subsystem - Low Head Safety Injection Pump
(1-SI-P-1A), on November 5, 2024
Inservice Testing (IST) (IP Section 03.01) (1 Sample)
(1)
1-PT-77.11B.1, Control Room Chiller 1-HV-E-4B IST Comprehensive Pump and
Valve Test, on November 13, 2024
71114.06 - Drill Evaluation
Additional Drill and/or Training Evolution (1 Sample)
The inspectors evaluated:
(1)
Licensed operator requalification training scenario SXG-28 in the control room
simulator, on December 10, and emergency preparedness drill SDEC24FS at the
Dominion corporate emergency response center, on December 17, 2024.
OTHER ACTIVITIES - BASELINE
71151 - Performance Indicator Verification
The inspectors verified licensee performance indicators submittals listed below:
MS06: Emergency AC Power Systems (IP Section 02.05) (2 Samples)
(1)
Unit 1 (October 1, 2023, to September 30, 2024)
(2)
Unit 2 (October 1, 2023, to September 30, 2024)
MS09: Residual Heat Removal Systems (IP Section 02.08) (2 Samples)
(1)
Unit 1 (October 1, 2023, to September 30, 2024)
(2)
Unit 2 (October 1, 2023, to September 30, 2024)
71152A - Annual Follow-up Problem Identification and Resolution
Annual Follow-up of Selected Issues (Section 03.03) (3 Samples)
The inspectors reviewed the licensees implementation of its corrective action program
related to the following issues:
(1)
CR1265323, I-IV Battery Charger Voltmeter Indicates Low Voltage on 'C'
Phase, on October 21, 2024
(2)
CR1269843, Potential 10 CFR Part 21 Concern for Cutler Hammer Freedom
Series Contactors, on October 22, 2024
(3)
CR1268759, Potential 10 CFR Part 21 Concern for the EDG Standby Lube Oil
Pump Main Contactor, on December 26, 2024
71152S - Semiannual Trend Problem Identification and Resolution
Semiannual Trend Review (Section 03.02) (1 Sample)
(1)
The inspectors reviewed the licensees corrective action program to identify potential
trends in containment isolation valves failing their timed stroke tests that might be
indicative of a more significant safety issue.
INSPECTION RESULTS
Observation: Semi-Annual Trend Review of Containment Isolation Valve Stroke
Test Failures
The inspectors performed a review of eight condition reports (CRs) written between January
2023 and December 2024 associated with containment isolation valve (CIV) stroke time test
failures. The review was performed to determine 1) if a trend existed, 2) identified issues
were not indicative of a more significant safety concern, and 3) issues were captured and
trended by the licensee. In all cases, upon discovery of the failures, the affected CIVs were
declared inoperable and their penetration flowpaths isolated within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />, and verified
isolated every 31 days, as required by North Anna, Units 1 and 2, Technical Specifications
(TS) Limiting Condition of Operation (LCO) 3.6.3, "Containment Isolation Valves." In total, six
valves were reviewed-unit 1, condenser air ejector divert (discharge) to containment inside
CIV (1-SV-TV-103); unit 1, pressurizer vapor space sample outside CIV (1-SV-TV-101B); unit
1, 'B' steam generator blowdown inside CIV (1-BD-TV-100D); unit 1, 'A' containment air
recirculation fan condensate return inside CIV (1-CC-TV-105A); unit 2, pressurizer relief tank
gas space inside CIV (2-SS-TV-204A), and unit 2, primary drain tank transfer pump discharge
outside CIV (2-DG-TV-204A). Three of which (1-SV-TV-103A, 2-SS-TV-204A, 2-DG-TV-
200A), had multiple, repetitive test failures. A summary of the CRs reviewed and the
inspectors' observations are below:
CR1272799 documents a failure of 1-BD-TV-100D to stroke within its test acceptance
criteria of 4.16 seconds (s) to 12.48s. In this instance, the licensee identified 1-BD-TV-
100D and nine other valves had been previously rebaselined; however, the test
acceptance criteria had not been appropriately updated. Per American Society of
Mechanical Engineers (ASME) Operation (OM) and Maintenance 2012 Code Edition,
reference values (acceptance criteria) may be rebaselined or revised following
maintenance that changes the performance characteristics of a valve. Once this issue
was identified, the licensee updated its test procedure, retested the valve satisfactorily
using new acceptance criteria, and the valve was declared operable. Based on this
information, the inspectors concluded no adverse trend existed.
CR1254980 documents failure of 1-CC-TV-105A to stroke within its test acceptance
criteria (8.5 seconds versus 11.99s to 19.97s). This issue was similar to the issue in
CR1272799. The test acceptance criteria was ultimately rebaselined, procedure
updated, and valve satisfactorily tested and declared operable. The CR also listed
several other CRs that were unrelated to stroke time testing; however, the CRs were
reviewed to ensure no performance issues existed. These CRs included CR1209302
(as-found Type C leakage exceeded), CR1178939 (valve operable but degraded due
to exceeding weak link analysis and operating in plastic deformation region thus
warranting replacement/upgrade), and CR1170124 (wear noted at valve shaft to valve
lever arm). None of the CRs were indicative of an adverse trend. A fourth CR was
also reviewed which discussed a post-maintenance (PMT) Type C test failure that
was evaluated for rework. A vendor investigation of the failure noted a lack of sealant
on the valve's pins, and pin manipulation from their original vendor-as-left state. The
inspectors concluded the licensee's failure to ensure design changes, i.e. pin
modification, were subject to design controls was a violation, and contrary to 10 CFR 50, Appendix B, Criterion III, "Design Control." This issue was assessed as minor
since the system was not required to be operable at the time the issue was identified.
CR1218600 documents failure of 2-SS-TV-204A to open during testing. Following the
test failure, the valve's limit switch was replaced, and the valve was satisfactorily
tested and restored to operable. A review of prior CRs written in the 2022 to 2023
timeframe noted two additional instances in which 2-SS-TV-204A lost indication or
failed to indicate open during testing. A corrective action was created to address the
limit switch issues; this included revising the preventive maintenance strategy for limit
switch replacement from 48 refueling outages (72 years) to 9 refueling outages (13.5
years). Additionally, the licensee's review of past performance issues including prior
limit switch replacements revealed this valve's limit switch was last replaced in 2007
due to corrosion and similar issues to those identified in the recent replacement. The
inspectors concluded that the licensee's failure to promptly identify and correct a
condition adverse to quality was a violation and contrary to 10 CFR 50, Appendix B,
Criterion XVI, "Corrective Actions." The inspectors assessed this issue to be minor
because it was similar to Examples 4.f and 4.g in Inspection Manual Chapter (IMC) 0612, Appendix E, Examples of Minor Issues, in that the failure to identify a
condition adverse to quality had no adverse impact on the valves function. Based on
their review, the inspectors determined no significant adverse trends existed.
CR1216398 documents failure of 1-SV-TV-101B to stroke within its test acceptance
criteria (5.53s versus 1.65s to 4.93s). Based on this failure, troubleshooting was
conducted which determined a limit switch adjustment was needed. Following the
adjustment, the valve was satisfactorily tested and restored to operable. During their
adjustments, the licensee noted the limit switch was aged and starting to degrade,
warranting future replacement. The inspectors noted commonality between this CR
and other CRs documenting limit switch issues and considered this a trend.
CR1236161 documents failure of 1-SV-TV-103 to open during testing. Licensee
troubleshooting determined the valve's solenoid operated valve (SOV) failed. The
licensee replaced the SOV and air supply regulator, and the valve was satisfactorily
tested and restored to operable. During their review of this CR, the inspectors
identified a minor finding associated with the station's failure to maintain the valve's
solenoid in accordance with vendor qualification report AQR-21678, when it did not
ensure the solenoid was maintained in its vendor-qualified, normally energized
configuration resulting in the valves failure to open. This issue was assessed to be
minor because it was similar to Example 3.a in IMC 0612, Appendix E, in that the
failure of the valve to open was inconsequential since this was not a safety function of
the valve and did not adversely affect the barrier integrity cornerstone objective to
protect the public against radionuclide releases.
CR1272357 documents failure of 1-SV-TV-103 to stroke open within its test
acceptance criteria (51.31s versus less than or equal to 30s). Due to its long history of
stroke issues, the licensee created an assignment for engineering to review valve
maintenance and performance history, including previous corrective actions. Based
on the pending assignment, engineering will recommend or initiate follow-on actions
to improve equipment reliability. No additional trends were identified.
CR1217915 documents test failure of 2-DG-TV-200A due to indicating mid-position.
Following satisfactory limit switch adjustment and PMT, the valve was declared
operable. The licensee flagged this issue for trending due to occurring four times in 3
years. Several engineering assignments were created to perform an aggregate review
of limit switch issues; initiate actions to improve equipment reliability; recommend
long-term corrective actions; and develop refresher training for limit switch setting and
adjustments based on other CRs written. One long-term corrective action was to
replace limit switches at shorter intervals due to vendor information that the switches
would not last the duration of their environmentally qualified life. A review of past
occurrences noted no limit switch issues until 2021; since then, four CRs were written.
Similar issues were identified in 2007 when limit switches were found corroded and in
need of replacement.
CR1216955 documents 1-SV-TV-103 experiencing continued issues while stroking
and a history of multiple stroke attempts using the test pushbutton. Based on this
occurrence, the licensee performed a historic review of valve performance to identify
any trends and noted a 2020 CR that cited a failure of 1-SV-TV-103 to stroke open.
The test pushbutton was later replaced in 2021 and a corrective action was assigned
to review the failure. An investigation revealed the 2020 failure was attributed to
contacts failing on the pushbutton. These contacts were noted as not being part of the
circuit for auto operation or isolation of the valve; thus, the failure only impacted the
test function.
Based on their review, the inspectors concluded a negative trend existed that was not
indicative of a more significant safety concern as there was no complete loss of safety
function of any system. Additionally, the inspectors noted corrective actions were taken or
planned to address and evaluate equipment reliability and programmatic/trend concerns.
While some test failures were foreseeable or preventable, none were of significant
consequence.
EXIT MEETINGS AND DEBRIEFS
The inspectors verified no proprietary information was retained or documented in this report.
On January 16, 2025, the inspectors presented the integrated inspection results to Lisa
Hilbert, Site Vice President, and other members of the licensee staff.