IR 05000336/2025011
| ML25350C111 | |
| Person / Time | |
|---|---|
| Site: | Millstone  |
| Issue date: | 12/17/2025 |
| From: | Erin Carfang Division of Operating Reactors |
| To: | Carr E Dominion Energy |
| References | |
| IR 2025011 | |
| Download: ML25350C111 (0) | |
Text
December 17, 2025
SUBJECT:
MILLSTONE POWER STATION, UNITS 2 AND 3 - DESIGN BASIS ASSURANCE INSPECTION (PROGRAMS) INSPECTION REPORT 05000336/2025011 AND 05000423/2025011
Dear Eric Carr:
On December 10, 2025, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection at Millstone Power Station, Units 2 and 3, and discussed the results of this inspection with James Petty, Senior 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, Erin E. Carfang, Chief Engineering Branch 1 Division of Operating Reactor Safety Docket Nos. 05000336 and 05000423 License Nos. DPR-65 and NPF-49
Enclosure:
As stated
Inspection Report
Docket Numbers:
05000336 and 05000423
License Numbers:
Report Numbers:
05000336/2025011 and 05000423/2025011
Enterprise Identifier: I-2025-011-0011
Licensee:
Dominion Energy Nuclear Connecticut, Inc.
Facility:
Millstone Power Station, Units 2 and 3
Location:
Waterford, CT
Inspection Dates:
September 22, 2025 to December 10, 2025
Inspectors:
K. Mangan, Senior Reactor Inspector
S. McClay, Reactor Inspector
J. Tifft, Senior Reactor Inspector
Approved By:
Erin E. Carfang, Chief
Engineering Branch 1
Division of Operating Reactor Safety
SUMMARY
The U.S. Nuclear Regulatory Commission (NRC) continued monitoring the licensees performance by conducting a design basis assurance inspection (programs) 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.
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 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
71111.21N.04 - Age-Related Degradation Age-Related Degradation
The inspectors selected a sample of components and structures to verify that engineering performance and maintenance activities addressed age-related degradation and that problems were appropriately identified, addressed, and corrected.
Samples were selected considering risk insights and the potential for degradation.
Specifically, the inspectors selected samples that were risk-significant and either had indications of age-related degradation or were exposed to environments that could cause age-related degradation. The inspectors considered site-specific and industry-wide operating experience to identify samples and included both active and passive sub-components within each component or structure.
For each selected sample listed below, the inspectors reviewed the licensees engineering and maintenance activities credited to address age-related degradation to assess whether they were being performed using applicable standards and procedures, evaluated against appropriate acceptance criteria, and that maintenance and condition monitoring was completed at an appropriate interval. The inspectors also assessed whether issues identified during licensee activities were being entered into and addressed by the applicable station processes including the corrective action program, and whether periodic assessments of maintenance effectiveness and operating experience were being completed, including feedback and process adjustments.
- (1) Unit 2, reactor building component cooling water pump
- (2) Unit 3, containment recirculation spray pump
- (3) Unit 3, service water strainer
- (4) Unit 3, turbine driven auxiliary feedwater
- (5) Unit 2, low pressure safety injection
- (6) Unit 2, service water piping
- (7) Unit 3, ventilation fans and dampers
- (8) Units 2 and 3, station blackout diesel
INSPECTION RESULTS
No findings were identified.
EXIT MEETINGS AND DEBRIEFS
The inspectors verified no proprietary information was retained or documented in this report.
- On December 10, 2025, the inspectors presented the design basis assurance inspection (programs) inspection results to James Petty, Senior Vice President, and other members of the licensee staff.
DOCUMENTS REVIEWED
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
71111.21N.04 Calculations
2017PA3056881_ECA
0.3
Unit 3 Programs Operator Credited
Actions
Corrective Action
Documents
1011518
1105574
1106152
1155099
1155384
1179384
1183162
1188959
201174
201734
210262
21101
27813
236949
249189
250708
252360
252856
257537
258562
264523
264815
294466
295635
296885
20972
Corrective Action
Documents
Resulting from
Inspection
1302414
1302455
1308827
1308808
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
Engineering
Evaluations
RCE: CA 118894
Service Water Pipe & Support Degradation in MP2
Service Water Pipe Tunnel
REA for Start Air
Drying Skid MP-2023-
014
Procedures
MP 3704A-600
SLCRS Isolation Damper Inspection
004
MP-PROC-ENG-EN
243
Millstone Unit 2 Service Water Pipe Liner/Coating
Inspection, Preventative Maintenance and
Surveillance Program
OP 3314J
Auxiliary Building Emergency Ventilation and Exhaust
006-00
SP 3670.4, MP-
PROC-OPS-OP
3346D, MP-PROC-
OPS-EOP 35 ECA-
0.0, MP-PROC-OPS-
EOP 35 ECA-0.3, ER-
AA-EDG-1001
Routine PMs, Station Blackout Diesel, Loss of All AC
Power, Loss of All AC Power - Recovery with the SBO
Diesel, Diesel Generator Reliability Program
Work Orders
WO 22492314
WO 53203338428
WO 53203439228
WO 53203468036