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Integrated Inspection Report 05000336/2024003 and 05000423/2024003 and Apparent Violation and Independent Spent Fuel Storage Installation Inspection Report 07200008/2024001
	ML24311A220
Person / Time
Site:	Millstone, Calvert Cliffs ; (DPR-065, NPF-049)
Issue date:	11/07/2024
From:	Matt Young; Division of Operating Reactors
To:	Carr E; Dominion Energy
References
	IR 2024001, IR 2024003
	Download: ML24311A220 (1)
	v • d • e

November 7, 2024

SUBJECT:

MILLSTONE POWER STATION, UNITS 2 AND 3 - INTEGRATED INSPECTION REPORT 05000336/2024003 AND 05000423/2024003 AND APPARENT VIOLATION AND INDEPENDENT SPENT FUEL STORAGE INSTALLATION INSPECTION REPORT 07200008/2024001

Dear Eric Carr:

On September 30, 2024, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection at Millstone Power Station, Units 2 and 3. On October 2, 2024, the NRC inspectors discussed the results of this inspection with Michael O'Connor, Site Vice President, and other members of your staff. The results of this inspection are documented in the enclosed report.

One Severity Level IV violation without an associated finding is documented in this report. We are treating this violation as a non-cited violation (NCV) consistent with Section 2.3.2 of the Enforcement Policy. We determined that additional follow-up using Inspection Procedure 92702, Follow-up on Traditional Enforcement Actions Including Violations, Deviations, Confirmatory Action Letters, Confirmatory Orders, and Alternative Dispute Resolution, was not warranted because the violation can be appropriately sampled using baseline inspection resources.

No NRC-identified or self-revealing findings were identified during this inspection.

A licensee-identified violation which was determined to be of very low safety significance is documented in this report. We are treating this violation as an NCV consistent with Section 2.3.2 of the Enforcement Policy.

If you contest the violations or the significance or severity of the violations 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 I; the Director, Office of Enforcement; and the NRC Resident Inspector at Millstone Power Station, Units 2 and 3. 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 07200008 License Nos. DPR-65 and NPF-49

Enclosure:

As stated

Inspection Report

Docket Numbers:

05000336, 05000423, and 07200008

License Numbers:

DPR-65 and NPF-49

Report Numbers:

05000336/2024003, 05000423/2024003, and 07200008/2024001

Enterprise Identifier: I-2024-003-0037 and I-2024-001-0061

Licensee:

Dominion Energy Nuclear Connecticut, Inc.

Facility:

Millstone Power Station, Units 2 and 3

Location:

Waterford, CT

Inspection Dates:

July 1, 2024 to September 30, 2024

Inspectors:

J. Fuller, Senior Resident Inspector

D. Antonangeli, Resident Inspector

E. Bousquet, Resident Inspector

N. Eckhoff, Health Physicist

C. Hargest, Health Physicist

M. Henrion, Senior Health Physicist

A. Kostick, Health Physicist

K. Mangan, Senior Reactor Inspector

N. Mentzer, Reactor Inspector

T. Winkel, 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. A licensee -identified non-cited violation (NCV) is documented in report Section 71111.0

List of Findings and Violations

Oil Leakage from Containment Recirculation Pump Motor Challenged Meeting Its Mission Time Resulting in a Condition Prohibited by Technical Specifications Cornerstone Severity Cross-Cutting Aspect Report Section Not Applicable Severity Level IV NCV 05000423/2024003-01 Open/Closed Not Applicable 71153 A self-revealed Severity Level IV NCV of Technical Specification (TS) 3.6.2.2, Recirculation Spray System, was identified when the licensee observed that the motor upper bearing oil level for the Unit 3 'C' containment recirculation spray system (RSS) pump (3RSS*P1C) was below the acceptance criteria.

Additional Tracking Items

Type Issue Number Title Report Section Status AV 05000336/2024001-01 Failure to Implement Structures Monitoring Program and Infrequently Accessed Areas Inspection Program for the Condensate Storage Tank Pipe Trench 71111.12 Discussed LER 05000423/2023-002-00 LER 2023-002-00 for Millstone Power Station,

Unit 3, Auxiliary Feedwater Control Valve Failure Resulting in a Condition Prohibited by Technical Specifications 71153 Closed LER 05000423/2023-005-00 LER 2023-005-00 for Millstone Power Station,

Unit 3, Oil Leakage from 'C'

RSS Pump Motor Challenged Meeting Its Mission Time Resulting in a Condition Prohibited by Technical Specifications 71153 Closed

PLANT STATUS

Unit 2 operated at or near rated thermal power for the entire inspection period.

Unit 3 began the inspection period at rated thermal power. On September 3, 2024, the unit was shut down for a planned maintenance outage to replace a pressurizer safety relief valve and reactor coolant pump seal. The unit was returned to rated thermal power on September 18, 2024, and remained at or near rated thermal power for the remainder of the 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, 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

71111.01 - Adverse Weather Protection

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

(1) The inspectors evaluated readiness for seasonal extreme weather conditions prior to the onset of seasonal hot temperatures during the week of July 6, 2024, for the following systems:

Units 2 and 3 intake building ventilation systems

Unit 3 engineered safety feature ventilation systems

Unit 3 emergency diesel generator enclosure

Station blackout diesel enclosure

71111.04 - Equipment Alignment

Partial Walkdown (IP Section 03.01) (3 Samples)

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

(1) Unit 2 'A' train of the main feedwater system in the turbine building on July 8, 2024

(2) Unit 3 'B' high-pressure safety injection from the refueling water storage tank to containment penetrations on July 16, 2024

(3) Unit 3 supplementary leak collection and release system in the auxiliary building near the waste disposal building exhaust fans on August 21, 2024

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 2 turbine lubricating oil system on the 14'-6" elevation (fire area T-2) on July 8, 2024

(2) Unit 2 sample sink area and A-12C boronmeter room in the auxiliary building on the 14'-6" elevation (fire area A-12B) on July 19, 2024

(3) Unit 2 waste gas decay tank area in the auxiliary building on the 14'-6" elevation (fire area A-1E) on July 26, 2024

(4) Unit 3 engineered safety features building, south containment recirculation cooler cubicle (fire area ESF-1), on August 29, 2024

(5) Unit 2 top of fuel pool and fuel handling area (fire area A-14C) on September 18, 2024

(6) Unit 3 turbine building operating floor, turbine shaft area, and general support lay down (fire areas TB-2D, TB-2E, and TB-2F) on September 25, 2024

(7) Unit 3 machine shop (fire areas MS-1A, MS-1B, MS-1C, MS-1D, MS-1E, MS-1F, MS-1G, MS-1H, and MS-1I) on September 25, 2024

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

(1) The inspectors evaluated the on-site fire brigade training and performance during response to a valid fire alarm for the Unit 2 service building on September 4, 2024

71111.06 - Flood Protection Measures

Flooding (IP Section 03.01) (1 Sample)

(1) The inspectors evaluated internal flooding mitigation protections in the Unit 3 emergency diesel generators enclosure building on September 5, 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) (2 Samples)

(1) The inspectors observed and evaluated licensed operator performance in the Unit 2 control room during operation of the 'A' emergency diesel generator and increased risk due to SPEC 200 card replacement on July 3, 2024, and during operators response to an unplanned reactor coolant system pressure transient on August 1, 2024.

(2) The inspectors observed and evaluated licensed operator performance in the Unit 3 control room during entry into a fire emergency operating procedure on July 10, 2024, and while operators performed a planned shutdown on September 3, 2024.

Licensed Operator Requalification Training/Examinations (IP Section 03.02) (2 Samples)

(1) The inspectors observed and evaluated Unit 3 operator requalification training on August 8, 2024.

(2) The inspectors observed and evaluated Unit 2 licensed operator performance during simulator training on shutdown plant conditions on August 28, 2024.

71111.12 - Maintenance Effectiveness

Maintenance Effectiveness (IP Section 03.01) (2 Samples)

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

(1) Unit 2 'A' control room air condition system maintenance rule a(1) evaluation

(2) Unit 3 emergency diesel generators maintenance rule monitoring and scoping

Quality Control (IP Section 03.02) (1 Sample)

The inspectors evaluated the effectiveness of maintenance and quality control activities to ensure the following SSC remains capable of performing its intended function:

(1) Unit 3 control of quality parts for 'B' pressurizer safety valve 3RCS*SV8010B (work order (WO) 53203408458)

71111.13 - Maintenance Risk Assessments and Emergent Work Control

Risk Assessment and Management (IP Section 03.01) (5 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 2 elevated risk during 'A' emergency diesel generator operation and online SPEC 200 card replacement when the 'A' reactor building closed-cooling water heat exchanger was out of service for inspection and cleaning on July 3, 2024

(2) Units 2 and 3 risk mitigating actions associated with the station blackout diesel out of service for planned maintenance on July 15, 2024 (WO53102548942)

(3) Unit 3 high-risk plan and associated mitigating actions associated with installation of a temporary modification (MP3-24-01062) for battery 6 on August 21, 2024 (WO53203423397)

(4) Unit 3 elevated risk during solid-state protection system testing while the reactor coolant system was operating under solid plant pressure control, which is an infrequently conducted and complex evolution, on September 6, 2024 (Surveillance Procedure (SP) 3446B11)

(5) Units 2 and 3 elevated risk and associated mitigating actions with Bus 24E out of service on September 23 and 24, 2024

71111.15 - Operability Determinations and Functionality Assessments

Operability Determination or Functionality Assessment (IP Section 03.01) (5 Samples)

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

(1) Unit 2 reserve station service transformer after receiving out of sync alarm on July 7, 2024 (CR1263558, CR1263797)

(2) Unit 2 operational decision-making checklist for the failure of both main pressurizer spray flow control valves on August 1, 2024 (CR1265532, CR1265633, CR1266044)

(3) Unit 3 operational decision-making checklist and associated trigger points for increased reactor coolant system leakage through the 'B' pressurizer safety relief valve on August 22, 2024 (CR1267068, CR1266657, CR1264896)

(4) Unit 3 reactor vessel head vent isolation valve did not show open indication when expected during surveillance testing on September 7, 2024 (CR1268273)

(5) Unit 2 structural integrity and operability evaluations for the water supply to all three auxiliary feedwater pumps due to a latent calculation error for a pipe support in the condensate storage tank (CST) pipe trench on September 16, 2024 (CR1258936)

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) Unit 2 temporary engineering change number MP2-24-01017, Temporary Change to M2TI-106 Pressurizer Relief Temp Set-Point, Revision 0, on July 2, 2024

71111.20 - Refueling and Other Outage Activities

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

(1) The inspectors evaluated Unit 3 forced outage activities from September 3 to 16, 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) (8 Samples)

(1) Unit 2 steam generator level transmitter (L52773A) after replacement of a failed circuit card on July 3, 2024 (WO53203423375, CR1263144)

(2) Units 2 and 3 station blackout diesel after planned maintenance on July 16, 2024 (WO53203409674)

(3) Unit 2 engineered safeguards actuation system channel for #1 steam generator pressure indication on July 19, 2024 (WO53203424473 and CR1264672)

(4) Unit 3 3HVK*CHL1B following maintenance outage during the week of July 22, 2024 (WO53203364234)

(5) Unit 3 mechanical cleaning of the heat exchanger for the west motor control center rod control and cable vault air conditioning unit on July 23, 2024 (WO53203383602)

(6) Unit 3 reinstallation of waste disposal exhaust fan, 3HVR*FN8A, as part of the boundary for the supplementary leak collection and release system on August 21, 2024 (CR1266993)

(7) Unit 3 replacement of the 'B' pressurizer safety relief valve on September 5, 2024 (WO53203408458)

(8) Unit 2 following repair of vital motor control center B51 air cooling unit, AC3, on September 19, 2024 (WO53203423527, WO53203438705)

Surveillance Testing (IP Section 03.01) (2 Samples)

(1) Unit 3 emergency diesel generator 'B' monthly operability test on July 23, 2024

(2) Unit 2 turbine-drive auxiliary feedwater surveillance testing on July 24, 2024

Reactor Coolant System Leakage Detection Testing (IP Section 03.01) (1 Sample)

(1) Unit 3 elevated unidentified leakage that met action level 3 limits on August 9, 2024 (CR1266108, CR1267066, CR1267610)

71114.06 - Drill Evaluation

Additional Drill and/or Training Evolution (1 Sample)

(1) The inspectors evaluated Unit 3 emergency planning drill and event classification in the simulator and emergency operations facility on August 20,

RADIATION SAFETY

71124.06 - Radioactive Gaseous and Liquid Effluent Treatment

Walkdowns and Observations (IP Section 03.01) (4 Samples)

The inspectors evaluated the following radioactive effluent systems during walkdowns:

(1) Unit 2 plant gaseous ventilation system and radiation monitor RM8132A/B

(2) Unit 2 liquid effluent radiation monitor system RM4262

(3) Unit 3 plant gaseous ventilation system and the charcoal banks 3HVR*FLT3A/B

(4) Unit 3 liquid effluent radiation monitor system 3SSR-RE08

Sampling and Analysis (IP Section 03.02) (4 Samples)

Inspectors evaluated the following effluent samples, sampling processes, and compensatory samples:

(1) Unit 3 charcoal and particulate filter air sample from 3HVQ-RE49

(2) Unit 3 analysis of charcoal and particulate sample from HVR-10B

(3) Unit 3 analysis of charcoal and particulate sample from HVR-19B

(4) Unit 2 analysis of charcoal and particulate sample from RM8169A

Dose Calculations (IP Section 03.03) (2 Samples)

The inspectors evaluated the following dose calculations:

(1) Analysis of annual gaseous effluent release projected dose estimates for 2023

(2) Unit 3 gaseous effluents through supplementary leakage collection and release system, effluent permit number G-EFF3-20240903-418-C

Abnormal Discharges (IP Section 03.04) (1 Sample)

The inspectors evaluated the following abnormal discharges:

(1) Unit 3 analysis of auxiliary building effluent discharge to DSN-006 for Co-60 and H-3 on April 16,

OTHER ACTIVITIES - BASELINE

===71151 - Performance Indicator Verification

The inspectors verified licensee performance indicators submittals listed below:

MS05: Safety System Functional Failures (SSFFs) (IP Section 02.04)===

Main article: IP 71151