IR 05000336/2025001
| ML25125A114 | |
| Person / Time | |
|---|---|
| Site: | Millstone  |
| Issue date: | 05/05/2025 |
| From: | Matt Young Division of Operating Reactors |
| To: | Carr E Dominion Energy |
| References | |
| IR 2025001 | |
| Download: ML25125A114 (1) | |
Text
May 5, 2025
SUBJECT:
MILLSTONE POWER STATION, UNITS 2 AND 3 - INTEGRATED INSPECTION REPORT 05000336/2025001 AND 05000423/2025001 AND INDEPENDENT SPENT FUEL STORAGE INSTALLATION INSPECTION REPORT 07200047/2025001
Dear Eric Carr:
On March 31, 2025, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection at Millstone Power Station, Units 2 and 3. On April 3, 2025, the NRC inspectors discussed the results of this inspection with James Petty, 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 (10 CFR) 2.390, Public Inspections, Exemptions, Requests for Withholding.
Sincerely, Matt R. Young, Chief Projects Branch 2 Division of Operating Reactor Safety
Docket Nos. 05000336, 05000423, and 07200047 License Nos. DPR-65 and NPF-49
Enclosure:
As stated
Inspection Report
Docket Numbers:
05000336, 05000423, and 07200047
License Numbers:
Report Numbers:
05000336/2025001, 05000423/2025001, and 07200047/2025001
Enterprise Identifier: I-2025-001-0052 and I-2025-001-0079
Licensee:
Dominion Energy Nuclear Connecticut, Inc.
Facility:
Millstone Power Station, Units 2 and 3
Location:
Waterford, CT
Inspection Dates:
January 1, 2025 to March 31, 2025
Inspectors:
J. Fuller, Senior Resident Inspector
D. Antonangeli, Resident Inspector
E. Bousquet, Resident Inspector
A. Christiano, Project Engineer
N. Eckhoff, Health Physicist
A. Kostick, Health Physicist
Approved By:
Matt R. Young, Chief
Projects Branch 2
Division of Operating Reactor Safety
SUMMARY
The U.S. Nuclear Regulatory Commission (NRC) continued monitoring the licensees performance by conducting an integrated inspection at Millstone Power Station, Units 2 and 3, 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
Both Units 2 and 3 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 2515, Light-Water Reactor Inspection Program - Operations Phase. The inspectors performed activities described in Inspection Manual Chapter 2515, Appendix D, Plant Status, conducted routine reviews using IP 71152, Problem Identification and Resolution, 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
71111.04 - Equipment Alignment
Partial Walkdown (IP Section 03.01) (4 Samples)
The inspectors evaluated system configurations during partial walkdowns of the following systems/trains:
- (1) Unit 3 'B' high-pressure safety injection from pump suction to the containment wall on January 16, 2025
- (2) Unit 3 emergency diesel generator (EDG) 'B' jacket water cooling system on January 21, 2025
- (3) Unit 2 auxiliary feedwater from steam supply piping to containment feed penetration from January 21 to 23, 2025
- (4) Unit 3 residual heat removal system train 'A' located in the engineered safety features building on January 30, 2025
71111.05 - Fire Protection
Fire Area Walkdown and Inspection (IP Section 03.01) (7 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) Unit 3 auxiliary building, east motor control center area, on the 24'-6" and 45'-6" elevations (fire area AB-5) while an hourly fire rove was in place due to the suppression system being out of service for repairs on January 3, 2025
- (2) Unit 2 turbine building, general area, on the 14'-6" elevation (fire areas T-1A and T-1B) on January 8, 2025
- (3) Unit 2 6.9 and 4.16 kilovolt switchgear room on the 31'-6" elevation (fire area T-7) on January 8, 2025
- (4) Unit 3 engineered safety features building, southeast floor area, auxiliary feedwater pump cubicle, on the 21'-6" elevation (fire area ESF-5) on January 10, 2025
- (5) Unit 2 enclosure building on all elevations (fire area E-1) from January 16 to 17, 2025
- (6) Unit 3 control room on the 4'-6" elevation (fire area CB-1) on February 24, 2025
- (7) Unit 2 auxiliary building, west piping penetration area, on the 5'-6" elevation (fire area A-8C) on March 6, 2025
Fire Brigade Drill Performance (IP Section 03.02) (1 Sample)
- (1) The inspectors evaluated the on-site fire brigade training and performance during an announced fire drill on March 6, 2025.
71111.06 - Flood Protection Measures
Flooding (IP Section 03.01) (1 Sample)
- (1) Unit 3 west switchgear room (flood area CB-1) on February 14, 2025
71111.07A - Heat Exchanger/Sink Performance
Annual Review (IP Section 03.01) (1 Sample)
- (1) The inspectors evaluated the readiness and performance of Unit 2 'C' reactor building component cooling water (RBCCW) heat exchanger including tube repair from February 24 to 26, 2025 (WO53203449743).
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 Unit 2 control room during the functional test of the control room radiation monitor, venting containment, and 'B' electro-hydraulic control uninterruptible power supply fan repair on March 17, 2025.
- (2) The inspectors observed and evaluated licensed operator performance in the Unit 3 control room during procedurally controlled high-risk activities on March 27, 2025.
Licensed Operator Requalification Training/Examinations (IP Section 03.02) (2 Samples)
- (1) The inspectors observed and evaluated licensed operator requalification training in the Unit 3 simulator on January 28, 2025.
- (2) The inspectors observed and evaluated licensed operator requalification training in the Unit 2 simulator on March 19, 2025.
71111.12 - Maintenance Effectiveness
Quality Control (IP Section 03.02) (1 Sample)
The inspectors evaluated the effectiveness of maintenance and quality control activities to ensure the following structures, systems, and components remain capable of performing their intended function:
- (1) Unit 2 SPEC-200 cabinet wiring change for 'B' feedwater regulating bypass valve (WO53203442273)
71111.13 - Maintenance Risk Assessments and Emergent Work Control
Risk Assessment and Management (IP Section 03.01) (6 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 3 elevated risk associated with planned battery charger 1 (301A-1) surveillances on January 6 and 7, 2025
- (2) Unit 2 elevated risk and mitigating actions associated with 'B' EDG testing on January 15, 2025
- (3) Unit 2 elevated risk and associated mitigating actions during troubleshooting of the 'A' EDG governor speed dial indication being offset on February 3 and 4, 2025
- (4) Unit 3 elevated risk associated with the extended duration of the 'B' control building chiller maintenance outage on March 3, 2025 (CR1284401)
- (5) Unit 3 procedurally controlled high-risk activities associated with surveillance testing of the solid state protection system and risk mitigating actions when the K653 relay failed to close on March 5, 2025
- (6) Unit 2 electro-hydraulic control system universal power supply charger 'B' fan replacement, single point vulnerability and medium risk plan, on March 10 and 17, 2025 (WO53203451472)
71111.15 - Operability Determinations and Functionality Assessments
Operability Determination or Functionality Assessment (IP Section 03.01) (8 Samples)
The inspectors evaluated the licensees justifications and actions associated with the following operability determinations and functionality assessments:
- (1) Unit 2 reactor protection system when the reactor trip coil, TCB-3, indication did not actuate, and alternate actions were required to verify that the trip coil and reactor trip breaker actuated during the surveillance test on January 2, 2025 (CR1279750)
- (2) Unit 3 elevated leakage from the reactor plant component cooling water system on January 9, 2025 (CR1280342, CR1280464)
- (3) Unit 2 'A' EDG governor speed dial indication was offset on January 31, 2025 (CR1282060)
- (4) Unit 3 lost communication and display of inadequate core cooling monitoring system during routine surveillance testing on February 17, 2025 (CR1283246)
- (5) Unit 2 RBCCW system leakage from the 'C' RBCCW heat exchanger on February 18, 2025 (CR1283317, CR1282250)
- (6) Unit 3 failed circuit card for steam line pressure lead/lag sensor, MSS*PY-524C, on February 19, 2025 (CR1283485)
- (7) Unit 3 'B' control building water chiller (HVK) after an unexpected pump trip due to low oil pressure on March 1, 2025 (CR1284401)
- (8) Unit 3 'B' reactor plant component cooling water system leakage into the reactor coolant system due to possible through-wall flaw in American Society of Mechanical Engineers Class 2 pressure boundary on March 24, 2025
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) Permanent change to a Generic Letter 89-13 commitment for the Unit 2 'A' and 'B' EDG jacket water heat exchanger cleaning time requirements on March 25, 2025
71111.20 - Refueling and Other Outage Activities
Refueling/Other Outage (IP Section 03.01) (1 Partial)
(1)
(Partial) Unit 3 new fuel receipt inspections during February and March 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 (IP Section 03.01) (8 Samples)
- (1) Unit 2 'B' high-pressure safety injection pump breaker (A503) after preventive maintenance on January 8, 2025 (WO53203230700, SP 2604AO-002)
- (2) Unit 3 fire water hydro-pneumatic tank operational test after discharge line blockage from January 8 to 9, 2025 (CR1279767)
- (3) Unit 3 instantaneous trip and time delay overcurrent test after cycling and cleaning of the motor control center breaker for the control room emergency ventilation fan on January 14, 2025 (WO53102534216)
- (4) Unit 3 post-maintenance testing after replacement of Westinghouse 7300 Series lead/lag MSS*PY-524C card on January 17, 2025 (WO53203447545)
- (5) Unit 3 replacement of mechanical seal for the control building air conditioning booster pump during the week of January 26, 2025 (WO53203407005)
- (6) Unit 2 'A' EDG after an adjustment was made to the governor speed dial indication offset from February 5 to 6, 2025 (WO53203448932)
- (7) Unit 2 'B' service water strainer timer calibration from March 18 to 19, 2025 (WO53203305204)
- (8) Unit 3 service water 'B' strainer after upper shoe pin and internal septum replacements on March 26, 2025 (WO53203452187)
Surveillance Testing (IP Section 03.01) (6 Samples)
- (1) Unit 2 reactor protection system matrix logic and trip path relay testing on January 2, 2025 (WO53203423657)
- (2) Unit 3 'A' EDG fast start surveillance on January 7, 2025
- (3) Unit 3 containment isolation phase 'A' relay actuation surveillance on January 8, 2025 (WO53203424012)
- (4) Unit 3 turbine-driven auxiliary feedwater pump operational readiness test on January 10, 2025
- (5) Unit 2 'B' EDG hot restart surveillance on January 15, 2025 (WO53203385680)
- (6) Unit 3 solid state protection system testing, SP 3446B11, on March 5 and 27, 2025 (WO53203428146)
Inservice Testing (IP Section 03.01) (1 Sample)
- (1) Unit 2 turbine-driven auxiliary feedwater pump, associated recirculation check valve, and steam supply valve inservice testing on January 21, 2025
71114.06 - Drill Evaluation
Required Emergency Preparedness Drill (1 Sample)
- (1) Unit 2 emergency planning drill on February 27,
RADIATION SAFETY
71124.03 - In-Plant Airborne Radioactivity Control and Mitigation
Permanent Ventilation Systems (IP Section 03.01) (1 Sample)
The inspectors evaluated the configuration of the following permanently installed ventilation systems:
- (1) Unit 2 control room ventilation system
Temporary Ventilation Systems (IP Section 03.02) (1 Sample)
The inspectors evaluated the configuration of the following temporary ventilation systems:
- (1) Unit 2 high-efficiency particulate ventilation system for the seal rebuild and decontamination room
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) Internal dose assessment for RP23-16
- (2) Internal dose assessment for RP24-16
Special Dosimetric Situations (IP Section 03.04) (2 Samples)
The inspectors evaluated the following special dosimetric situations:
- (1) Neutron dosimetry program and assessment
- (2) Effective dose equivalent for external exposures for RWP 306-3
71124.08 - Radioactive Solid Waste Processing and Radioactive Material Handling, Storage,
and Transportation
Shipment Preparation (IP Section 03.04)
- (1) The inspectors observed the preparation of radioactive shipment 25-006 on January 28,
OTHER ACTIVITIES - BASELINE
===71151 - Performance Indicator Verification
The inspectors verified licensee performance indicators submittals listed below:
BI01: Reactor Coolant System Specific Activity (IP Section 02.10)===
- (1) Unit 2 (January 1, 2024 through December 31, 2024)
- (2) Unit 3 (January 1, 2024 through December 31, 2024)
BI02: Reactor Coolant System Leak Rate (IP Section 02.11) (2 Samples)
- (1) Unit 2 (January 1, 2024 through December 31, 2024)
- (2) Unit 3 (January 1, 2024 through December 31, 2024)
OTHER ACTIVITIES
- TEMPORARY INSTRUCTIONS, INFREQUENT, AND ABNORMAL
===60859 - Independent Spent Fuel Storage Installation (ISFSI) License Renewal Inspection
The inspectors evaluated the licensees ISFSI license renewal program from December 16, 2024, through February 18, 2025, including observation of the licensees baseline canister inspection and review of licensee compliance with NRC regulations, license conditions, and technical specifications as required under Title 10 of the Code of Federal Regulations (10 CFR) Part 72 and the Certificate of Compliance 1004, License Amendments 15, and Final Safety Analysis Report, Revision 18.
ISFSI License Renewal Inspection===
- (1) The inspectors conducted the following activities and interviewed site personnel to assess compliance with NRC regulations, license conditions, and technical specifications:
- Observation of the sites baseline (lead canister) aging management inspection
- Review of the licensees aging management basis documentation to include identification and evaluation of site-specific time limited aging analyses and lead canister selection criteria, aging management inspection acceptance criteria, and aging management corrective action procedures
- Review of the licensees scoping, planning, and subsequent implementation of ISFSI aging management programs (AMPs) required for the various structures, systems, and components which required an AMP per licensing requirements
- Review of 10 CFR 72.48 screenings and evaluations related to ISFSI license renewal and aging management activities
- Assessment of the licensees acceptance criteria and corrective action program for the AMPs, with a focus on assessing the licensees planned measures in the event of an aging management acceptance criterion not being met
- Review of the licensees method(s) to collect and assess the effectiveness of the operating experience associated with the ISFSI license renewal and aging management activities throughout the period of extended operation or identify the need for AMP modifications, as warranted
- Review of licensee administrative controls (i.e., aging management procedures and preventive/corrective action procedures) associated with ISFSI license renewal and aging management activities
INSPECTION RESULTS
No findings were identified.
EXIT MEETINGS AND DEBRIEFS
The inspectors verified that no proprietary information was retained or documented in this report.
- On February 4, 2025, the inspectors presented the in-plant airborne and occupational dose inspection results to James Petty, Site Vice President, and other members of the licensee staff.
- On February 18, 2025, the inspectors presented the ISFSI results to James Petty, Site Vice President, and other members of the licensee staff.
- On April 3, 2025, the inspectors presented the integrated inspection results to James Petty, Site Vice President, and other members of the licensee staff.
DOCUMENTS REVIEWED
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
Corrective Action
Documents
Resulting from
Inspection
CR1280156
CR1280605
CR1281569
CR1282560
CR1282616
CR1284950
Calculations
P(R)-711
Reactor Plant Component Cooling System Surge Tank
Sizing
Revision 03,
Addendum A
Engineering
Evaluations
ETE-MP-2025-
1019
Implementation of Unit 3 RPCCW Surge Tank Allowable
Leakage Limit Calculation
Revision 0
Procedures
SP 3622.3
Auxiliary Feedwater Pump 3FWA*P2 Operational Readiness
Test
Revision 39