IR 05000220/2025004

Integrated Inspection Report 05000220/2025004 and 05000410/2025004 and Independent Spent Fuel Storage Installation Inspection Report 07201036/2024001 and Exercise of Enforcement Discretion

ML26043A005
Person / Time
Site:	Nine Mile Point
Issue date:	02/12/2026
From:	Jason Schussler Division of Operating Reactors
To:	Mudrick C Constellation Energy Generation, Constellation Nuclear
References
EAF-NMSS-2025-0220 IR 2025004, IR 2024001
Download: ML26043A005 (0)

Text

February 12, 2026

SUBJECT:

NINE MILE POINT NUCLEAR STATION, UNITS 1 AND 2 - INTEGRATED INSPECTION REPORT 05000220/2025004 AND 05000410/2025004 AND INDEPENDENT SPENT FUEL STORAGE INSTALLATION INSPECTION REPORT 07201036/2024001 AND EXERCISE OF ENFORCEMENT DISCRETION

Dear Christopher Mudrick:

On December 31, 2025, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection at Nine Mile Point Nuclear Station, Units 1 and 2. On January 22, 2026, the NRC inspectors discussed the results of this inspection with Tim Peter, Site Vice President, and other members of your staff. The results of this inspection are documented in the enclosed report.

One finding of very low safety significance (Green) is documented in this report. This finding 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.

The NRC identified a violation of Title 10 of the Code of Federal Regulations (10 CFR) 72.48, paragraphs (c)(1), (c)(2), and (d)(1), and provisions of 10 CFR 72.212 that resulted from a Certificate of Compliance (CoC) holders failure to comply with 10 CFR 72.48 for a CoC holder-generated change for the Holtec continuous basket shim multi-purpose canister variant design.

However, an Interim Enforcement Policy issued in August 2025 is applicable to this violation.

Specifically, Enforcement Policy Section 9.4, Enforcement Discretion for General Licensee Adoption of Certificate of Compliance (CoC) Holder-Generated Modifications under 10 CFR 72.48, provides enforcement discretion to not issue an enforcement action for this violation.

The licensee will be expected to comply with 10 CFR 72.212 provisions after the NRC dispositions the noncompliance for a CoC holder-generated change that affects the general licensee. 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 I; the Director, Office of Enforcement; and the NRC Resident Inspector at Nine Mile Point Nuclear Station, Units 1 and 2.

If you disagree with a cross-cutting aspect assignment 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 I; and the NRC Resident Inspector at Nine Mile Point Nuclear Station, Units 1 and 2.

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 10 CFR 2.390, Public Inspections, Exemptions, Requests for Withholding.

Sincerely, Jason E. Schussler, Chief Projects Branch 1 Division of Operating Reactor Safety

Docket Nos. 05000220, 05000410, and

07201036 License Nos. DPR-63 and NPF-69

Enclosure:

As stated

Inspection Report

Docket Numbers:

05000220, 05000410, and 07201036

License Numbers:

DPR-63 and NPF-69

Report Numbers:

05000220/2025004, 05000410/2025004, and 07201036/2024001

Enterprise Identifier: I-2025-004-0045 and I-2024-001-0104

Licensee:

Constellation Energy Generation, LLC

Facility:

Nine Mile Point Nuclear Station, Units 1 and 2

Location:

Oswego, NY

Inspection Dates:

October 1, 2025 to December 31, 2025

Inspectors:

E. Miller, Senior Resident Inspector

E. Adams, Resident Inspector

B. Sienel, Resident Inspector

H. Anagnostopoulos, Senior Health Physicist

C. Borman, Health Physicist

B. Dyke, Senior Operations Engineer

T. Fish, Senior Operations Engineer

A. Kostick, Health Physicist

R. Riggs, Reactor Engineer

Approved By:

Jason E. Schussler, Chief

Projects Branch 1

Division of Operating Reactor Safety

SUMMARY

The U.S. Nuclear Regulatory Commission (NRC) continued monitoring the licensees performance by conducting an integrated inspection at Nine Mile Point Nuclear 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

Fire Detector Initiation Causes Unit 2 Station Transient Cornerstone Significance Cross-Cutting Aspect Report Section Initiating Events Green NCV 05000410/2025004-01 Open/Closed

[H.12] - Avoid Complacency 71153 A self-revealed Green finding and associated non-cited violation (NCV) of Technical Specification (TS) 5.4.1(a), Procedures, was identified when the licensee failed to follow a procedure during a Unit 2 fire system test. Specifically, while performing fire detector testing, a technician failed to follow a caution statement as well as component identification and verification leading to an inadvertent initiation of the fire suppression system. The initiation led to a trip of the A condensate pump and a station transient.

Additional Tracking Items

Type Issue Number Title Report Section Status EDG EAF-NMSS-2025-0220 Noncompliance Related to a General Licensees Use of Non-Qualified Spent Fuel Casks (IEP 9.4)60855 Closed URI 05000220/2025002-01 Calibration of Containment High Range Radiation Monitor (CHRRM) System 71124.05 Closed

PLANT STATUS

Unit 1 remained at or near rated thermal power (RTP) throughout the inspection period.

Unit 2 began the inspection period at RTP. On October 3, 2025, operators reduced reactor power to 63 percent to perform power suppression testing. During power ascension on October 6, 2025, operators held power at 85 percent to investigate and isolate an electrohydraulic fluid oil leak. After isolation, operators restored reactor power to RTP on October 6, 2025. On November 8, 2025, operators reduced reactor power to 82 percent for a planned rod pattern adjustment. Power was restored to RTP the following day. On November 13, 2025, there was an unplanned power reduction to approximately 42 percent following the inadvertent actuation of a fire suppression system and the resultant motor fault and trip of the 'A' condensate pump, followed by the trip of the 'A' condensate booster and 'B' feedwater pumps. Following the replacement of the 'A' condensate pump motor, operators restored power to RTP on November 21, 2025. On December 12, 2025, operators performed a power reduction to 70 percent to perform a planned rod pattern adjustment. Operators restored reactor power to RTP on December 14, 2025. On December 28, 2025, operators performed a power reduction to 91 percent to perform a planned rod pattern adjustment. Operators subsequently restored reactor power to RTP on December 29, 2025. Unit 2 remained at RTP for the rest 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, 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.

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 November 4, 2025:

• Unit 1, emergency diesel generators (EDGs) 102 and 103

• Unit 1, 125V batteries 11 and 12

• Unit 2, Divisions I, II, and III EDGs

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, Division II EDG on October 14, 2025

(2) Unit 2, standby gas treatment train 'A' on December 4, 2025

71111.05 - Fire Protection

Fire Area Walkdown and Inspection Sample (IP Section 03.01) (5 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 1, reactor building 298', fire area 92, on October 27, 2025

(2) Unit 2, turbine building 250', fire area 50, on November 20, 2025

(3) Unit 1, screenhouse 261', fire area 52, on November 26, 2025

(4) Unit 1, turbine building 300', fire area 95, on December 1, 2025

(5) Unit 2, reactor building 261', fire area 74, on December 4, 2025

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

(1) The inspectors evaluated the onsite fire brigade training and performance during an announced fire drill on December 9, 2025.

71111.07A - Heat Exchanger/Sink Performance

Annual Review (IP Section 03.01) (1 Sample)

The inspectors evaluated readiness and performance of:

(1) Unit 1, 11 reactor building closed loop cooling heat exchanger on December 2, 2025

===71111.11A - Licensed Operator Requalification Program and Licensed Operator Performance

Requalification Examination Results (IP Section 03.03)===

(1) The inspectors reviewed and evaluated the Unit 2 licensed operator examination failure rates for the requalification annual operating exams administered October - November 2025 and the biennial written examinations administered October - November 2025.

(2) The inspectors reviewed and evaluated the licensed operator examination failure rates for the Unit 1 requalification annual operating exam completed on November 14, 2025.

71111.11B - Licensed Operator Requalification Program and Licensed Operator Performance Licensed Operator Requalification Program (IP Section 03.04)

(1) Biennial Requalification Written Examinations

The inspectors evaluated the quality of the Unit 2 licensed operator biennial requalification written examinations administered October - November 2025.

Annual Requalification Operating Tests

The inspectors evaluated the adequacy of the Unit 2 annual requalification operating test administered week of October 13, 2025.

Administration of an Annual Requalification Operating Test

The inspectors evaluated the effectiveness of the facility licensee in administering requalification operating tests required by Title 10 of the Code of Federal Regulations (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)

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(1) The inspectors observed and evaluated Unit 2 licensed operator performance in the control room during a power reduction to 63 percent for power suppression testing on October 3 and 4, 2025.

(2) The inspectors observed and evaluated Unit 1 licensed operator performance in the control room during core spray system testing on November 18, 2025.

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

(1) The inspectors observed a Unit 1 annual simulator exam with scenarios that included instrumentation failures, pump trips, drifting control rods, and leaks in primary containment on October 21, 2025.

(2) The inspectors observed a Unit 2 annual simulator exam with scenarios that included unexpected emergency core cooling system initiation, a turbine building closed loop cooling temperature controller malfunction, a feedwater failure, and an anticipated transient without scram on October 21, 2025.

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 functions:

(1) Unit 1, reactor building emergency ventilation system on October 9, 2025

(2) Unit 2, secondary containment bypass leakage on October 29, 2025

(3) Unit 2, SSCs associated with plant level events (scrams) on December 16, 2025

71111.13 - Maintenance Risk Assessments and Emergent Work Control Risk Assessment and Management Sample (IP Section 03.01)

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 unplanned inoperability of the Division I EDG on October 14, 2025

(2) Unit 2, 'A' condensate pump trip and additional actions for power ascension on November 14, 2025

71111.15 - Operability Determinations and Functionality Assessments Operability Determination or Functionality Assessment (IP Section 03.01)

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

(1) Unit 2, control rod 30-31 high temperature on October 1, 2025

(2) Unit 2, 2VBB-UPS3A, uninterruptible power supply 3A, following battery supply alarm on October 1, 2025

(3) Unit 2, 2BYS-BAT1C, non-class 1E station battery, following inspector identification of negative plate shedding and failed attempts to perform load testing on October 2, 2025

(4) Unit 1, high pressure core spray function following feedwater booster pump 13 motor bearing temperatures trending high on October 7, 2025

(5) Unit 1, core spray 122 following overcurrent relay target in on operator rounds on October 15, 2025

(6) Unit 2, potential through-wall leak on service water pipe 2-SWP-006-107-3 on reactor building 240' on October 29, 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 (PMT) (IP Section 03.01)===

(1) Unit 1, core spray system 122 following planned breaker maintenance on October 9, 2025

(2) Unit 2, Division I EDG following unplanned maintenance on October 14, 2025

(3) Unit 2, reactor core isolation cooling system following planned maintenance on November 25, 2025

(4) Diverse and Flexible Coping Strategies (FLEX) diesel 'C' loaded run following battery replacement, battery charger replacement, and coolant leak repair on November 25, 2025

(5) Unit 2, containment atmospheric particulate radiation monitor, 2CMS*CAB10A2, following identification of water intrusion on December 23, 2025

Surveillance Testing (IP Section 03.01) (1 Sample)

(1) Unit 2, NF-AB-431, Power Suppression Testing, on October 3-4, 2025

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

(1) Unit 2, elevated drywell floor drain leakage investigation using resistance readings of potential leaking motor operated valves on December 16,

71124.05 - Radiation Monitoring Instrumentation

Calibration and Testing Program (IP Section 03.02) (1 Sample)

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

(1) Unit 1, Containment High Range Radiation Monitors, General Atomics Model RD-23, S/N 040 and 142

===71124.08 - Radioactive Solid Waste Processing & Radioactive Material Handling, Storage, & Transportation

Radioactive Material Storage (IP Section 03.01)===

The inspectors evaluated the licensees performance in controlling, labeling, and securing the following radioactive materials:

(1) Accessible drums, boxes, bags, and packages located within the Unit 0, 261' cold storage building

Radioactive Waste System Walkdown (IP Section 03.02) (1 Sample)

The inspectors walked down the following accessible portions of the solid radioactive waste systems and evaluated system configuration and functionality:

(1) Unit 2, dry active waste processing, handling, and storage facilities in the radioactive waste and condensate storage tank buildings

Waste Characterization and Classification (IP Section 03.03) (2 Samples)

The inspectors evaluated the following characterization and classification of radioactive waste:

(1) Fourteen drums of bead resins and sand blasting grit as described in radioactive waste shipment NMP-2024-2060

(2) Bead resins waste liner U1-25-002 as described in radioactive waste shipment NMP-2025-1025

Shipment Preparation (IP Section 03.04) (1 Sample)

(1) Shipment NMP-2025-1229, UN2910 Limited Quantity, reactor building closed loop cooling system motor

Shipping Records (IP Section 03.05) (3 Samples)

The inspectors evaluated the following non-excepted radioactive material shipments through a record review:

(1) Radioactive materials shipment NMP-2023-2028, UN3321 LSA-II

(2) Radioactive materials shipment NMP-2023-1183, UN2915 Type A Package

(3) Radioactive materials shipment NMP-2025-1229, UN2910 Limited Quantity

OTHER ACTIVITIES - BASELINE

===71151 - Performance Indicator Verification

The inspectors verified licensee performance indicators submittals listed below:

MS08: Heat Removal Systems (IP Section 02.07)===

(1) Unit 1, for the period October 1, 2024 through September 30, 2025

(2) Unit 2, for the period October 1, 2024 through September 30, 2025

MS09: Residual Heat Removal Systems (IP Section 02.08) (2 Samples)

(1) Unit 1, for the period October 1, 2024 through September 30, 2025

(2) Unit 2, for the period October 1, 2024 through September 30, 2025

MS10: Cooling Water Support Systems (IP Section 02.09) (2 Samples)

(1) Unit 1, for the period October 1, 2024 through September 30, 2025

(2) Unit 2, for the period October 1, 2024 through September 30, 2025

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

(1) Units 1 and 2, for the period October 1, 2024 through September 30, 2025

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) Units 1 and 2, for the period October 1, 2024 through September 30, 2025

71152A - Annual Follow-up Problem Identification and Resolution Annual Follow-up of Selected Issues (Section 03.03)

The inspectors reviewed the licensees implementation of its corrective action program related to the following issues:

(1) Issue Report (IR) 04905397 - Unit 2 Division I EDG Cylinder 8L Air Intake Lubricating Oil Leak

(2) IR 04812871 - Unit 1 Fuel Element Defect

71152S - Semiannual Trend Problem Identification and Resolution Semiannual Trend Review (Section 03.02)

(1) The inspectors reviewed the licensees corrective action program to identify potential trends that might be indicative of a more significant safety issue.

71153 - Follow-Up of Events and Notices of Enforcement Discretion Personnel Performance (IP Section 03.03)

(1) Unit 2, electrohydraulic fluid leak from turbine control valve 1 fast acting solenoid pressure transmitter on October 6, 2025

(2) Unit 2, Division I EDG unplanned inoperability and unavailability due to an air intake manifold oil leak on October 14, 2025

(3) Unit 1, 13 reactor water recirculation pump unexpected speed change on November 13, 2025

(4) Unit 2, 2CNM-P1A, 'A' condensate pump motor trip and power reduction to 45 percent following a fault caused by inadvertent fire system sprinkler initiation on turbine building 277' on November 13,

2025 OTHER ACTIVITIES

- TEMPORARY INSTRUCTIONS, INFREQUENT AND ABNORMAL

===60855 - Operation of an Independent Spent Fuel Storage Installation (ISFSI)

Inspections were conducted using the appropriate portions of the 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 IMC 2690, Inspection Program for Storage of Spent Reactor Fuel and Reactor-Related Greater-than-Class C Waste at Independent Spent Fuel Storage Installations (ISFSI) and for 10 CFR Part 71 Transportation Packagings."

Operation of an Independent Spent Fuel Storage Installation===

(1) The inspectors conducted a periodic in-office follow-up that focused on the review of the general licensees (GLs) implementation of the 10 CFR 72.48 process and associated corrective actions related to ISFSI activities. The review included:

• 10 CFR 72.48 Evaluations and Screenings: Reviewed the GLs 10 CFR 72.48 process and associated evaluation associated with the adoption of the continuous basket shim (CBS) variant.

• Corrective Action Program: Reviewed condition reports related to the design change of the CBS variant.

INSPECTION RESULTS

Enforcement Discretion Enforcement Action EAF-NMSS-2025-0220: Noncompliance Related to a General Licensees Use of Non-Qualified Spent Fuel Casks (IEP 9.4)60855

Description:

Holtec International (also referred to as the CoC (Certificate of Compliance)holder) implemented a design change to its multi-purpose canister fuel basket, known as the CBS variant, which altered the structural configuration from welded to bolted shims. This change resulted in a departure from the method of evaluation (MOE) described in the final safety analysis report (FSAR) used to establish the design basis for tip-over events. Holtec did not fully evaluate the cumulative impact of the MOE changes or apply them consistently with the licensing basis. As a result, the NRC issued three Severity Level IV violations to Holtec for noncompliance with 10 CFR 72.48 requirements (see U.S. Nuclear Regulatory Commission Inspection Report 07201014/2022-201, Holtec International, Agencywide Documents Access and Management System (ADAMS) Accession No. ML23145A175, and Holtec International, Inc. - Notice of Violation; The U.S. Nuclear Regulatory Commission Inspection Report No.

07201014/2022-201, ML24016A190).

When the GL chooses to adopt a change the CoC holder made pursuant to a CoC holder's change authority under 10 CFR 72.48 (referred to herein as a CoC holder-generated change), the GL must perform a separate review using the requirements of 10 CFR 72.48(c). Accordingly, when the GL chooses to adopt a CoC holder-generated change, and that change results in a non-conforming cask, there is a violation of 10 CFR 72.48 and certain provisions of 10 CFR 72.212 by the GL, in addition to a CoC holder violation of 10 CFR 72.48. As it relates to the adoption of the CBS variant casks, the GL failed to recognize the noncompliance with 10 CFR 72.48 requirements made by the CoC holders design change and subsequently loaded the CBS variant casks.

Corrective Actions: The GL entered this into its corrective action program with actions to restore compliance with the 10 CFR 72.212 provisions that require each cask to conform to the terms, conditions, and specifications of a CoC or an amended CoC listed in 10 CFR 72.214.

Corrective Action References: IR 04831865, ECP-25-000016

Enforcement:

Significance/Severity: This violation was dispositioned in accordance with Section 9.4, Enforcement Discretion for General Licensee Adoption of CoC Holder-Generated Changes Under 10 CFR 72.48, of the NRCs Enforcement Policy.

Specifically, as stated in the Policy, the NRC will exercise enforcement discretion and not issue an enforcement action to a GL, for a noncompliance with the requirements of paragraphs (c)(1) and

(2) and (d)(1) of 10 CFR 72.48 and with provisions of 10 CFR 72.212 that require GLs to ensure use of casks that conform to the terms, conditions and specifications of a CoC listed in 10 CFR 72.214, when the noncompliance results from a CoC holders failure to comply with 10 CFR 72.48 for a CoC holder-generated change.

Violation: 10 CFR 72.48 (c)(1) requires, in part, that a licensee or certificate holder may make changes in the facility or spent fuel storage cask design as described in the FSAR (as updated), without obtaining:

(ii) CoC amendment submitted by the certificate holder pursuant to § 72.244 if:

(c) The change, test, or experiment does not meet any of the criteria in paragraph (c)(2) of this section.

10 CFR 72.48(c)(2) requires, in part, that a GL shall request that the certificate holder obtain a CoC amendment, prior to implementing a proposed change, if the change would: (viii) Result in a departure from an MOE described in the FSAR used in establishing the design bases or in the safety analyses.

10 CFR 72.48(d)(1) requires, in part, that the licensee shall have a written evaluation which provides the bases for the determination that the change does not require a CoC amendment pursuant to 10 CFR 72.48(c)(2).

10 CFR 72.212(b)(3) requires, in part, a GL must ensure that each cask used by the GL conforms to the terms, conditions, and specifications of a CoC or an amended CoC listed in 10 CFR 72.214.

Contrary to the above, in May 2022, the GL loaded the first CBS design variant and failed to maintain records of changes in the spent fuel storage cask design made pursuant to 10 CFR 72.48(c) that include a written evaluation which provided the bases for the determination that the change did not require a CoC amendment. The GL failed to request that the certificate holder obtain a CoC amendment, prior to implementing a proposed change, if the change would: (viii) result in a departure from an MOE described in the FSAR used in establishing the design bases or in the safety analyses. Further, the GL failed to ensure each cask conformed to the terms, conditions, and specifications of a CoC or amended CoC listed in 10 CFR 72.214.

Basis for Discretion: When a GL chooses to adopt a CoC holder-generated change, and that change results in a non-conforming cask, there is a violation of 10 CFR 72.48 and certain provisions of 10 CFR 72.212 by the GL, in addition to a CoC holder violation of 10 CFR 72.48.

And, when a GL chooses to adopt a CoC holder-generated change without performing a separate 10 CFR 72.48 analysis, the GL is in violation of 10 CFR 72.48. These requirements could lead to enforcement actions being issued against both the GL's 10 CFR 72.48 program (as well as certain 10 CFR 72.212 violations) and the CoC holder's 10 CFR 72.48 program for changes that originated with the CoC holder. The NRC has concluded that this enforcement approach would be inconsistent with efficiency, which is one of the NRC's Principles of Good Regulation, and NRC's mission of efficient and reliable oversight.

Since this violation meets the conditions of the NRC's Enforcement Policy Section 9.4, "Enforcement Discretion for General Licensee Adoption of Certificate of Compliance Holder-Generated Changes under 10 CFR 72.48" (ML25224A097), and the GL has entered the noncompliance into the corrective action program, the NRC is exercising enforcement discretion by not issuing an enforcement action for this violation.

Unresolved Item (Closed)

Calibration of Containment High Range Radiation Monitor (CHRRM) System URI 05000220/2025002-01 71124.05

Description:

Nine Mile Point Unit 1, CHRRMs 201.7-36 and 201.7-37 are augmented quality and provide indication of radiological conditions in the primary containment during a postulated loss of coolant accident. During review of the calibration history and design calculations, the inspectors identified an unresolved item (URI) associated with Constellations calibration program for Unit 1 CHRRMs, as documented in Inspection Report 05000220/2025002 and URI 05000220/2025002-01. In 2025, Constellation revised its calibration methodology by changing the reference source from cobalt-60 (Co-60) to cesium-137 (Cs-137). At the time of the inspection, Constellation was unable to provide a sufficient technical basis to support this change.

Calculation LA-RR-201.7-36C, Drywell High-Range Gamma Radiation Loop Accuracy, provides a calibration frequency, calibration method, and calibration source as part of the instrument uncertainty analysis. On January 28, 2021, Constellation changed the calibration frequency from 24 months to 48 months, as documented in CC-AA-309-1001-F-01, Justification of Proposed Extension for Surveillance Interval Requirements for the Drywell High Range Gamma Radiation System, Design Analysis Number ECP-21-000007-MU-002 NER-1I-022. In addition, on March 5, 2025, Constellation made a change to the instrument calibration method by changing the instrument calibration source from Co-60 to a Cs-137 source, as documented in procedure change review and 50.59 screening PCR-25-0032, The Use and Routine Calibration of the General Atomic High Range Gamma Radiation Monitoring System.

The inspectors identified that calculation LA-RR-201.7-36C was not revised to account for the changes in calibration frequency and instrument calibration source, which can affect the methodology used in the calculation and uncertainty calculation results. CC-AA-309, Control of Design Analyses, Revision 13, provides steps for control of design changes such as calculations that support safety-related and augmented quality systems. Step 4.4.5 provides methods to consider detailed design review methods or alternate calculation review. As part of final design change approval, Step 4.5.3 states, confirm that critical parameters are appropriately identified, and sources are documented and validated.

Procedure CC-AA-103-2001, Setpoint Change Control, Revision 5 provides direction for managing setpoint changes and a roadmap to the various documents within Constellation that are used in the calculation of setpoints, the analysis of instrument channel setpoint error and instrument loop accuracy, and scaling calculations. It provides recognition of Constellation stations committed to different setpoint methodologies commensurate with various submittals that have been made to the NRC. It provides recognition that the entire calibration program for a site has been developed around these methodologies and specific vendor documents, which would prevent standardization of all processes to the same instrument calibration program and calculation of setpoints and scaling methodologies. For setpoint calculations, Step 4.3.5 states, in all cases the method used shall be documented and appropriate justification included in the configuration change package for the method used and the uncertainty calculation that was performed.

The inspectors determined that Constellation did not follow the design change process in accordance with CC-AA-309 and CC-AA-103-2001 to ensure that changes associated with the CHRRM calibration method and uncertainty analysis were identified, reviewed, documented and approved prior to calibration of CHRRMs 201.7-36 and 201.7-37. This was determined to be a performance deficiency.

The inspectors also identified a minor violation of Nine Mile Point Unit 1 TS 6.4.1, Procedures, due to not having an adequate maintenance procedure to perform calibrations of the CHRRMs as required by Regulatory Guide 1.33, Appendix A, dated November 3, 1972.

Specifically, N1-RSP-10C, The Use and Routine Calibration of the General Atomic High Range Gamma Radiation Monitoring System, Revision 9 was not adequate between June 12, 2025 and January 31, 2026, because calculation LA-RR-201.7-36C was not revised to account for the changes in calibration frequency and instrument calibration source, which can affect the methodology used in the calculation and uncertainty calculation results. As a result, the calibration was susceptible to not providing accurate results without an adequate supporting uncertainty calculation.

The inspectors screened the issues in accordance with IMC 0612, Appendix B and determined the issues to be minor. Specifically, Constellation generated IRs 04872407 and 04891925 to perform the uncertainty calculation with the updated methodology. The inspectors determined the results of the calculation as documented in Engineering Change 646905, "Drywell Hi-Range Gamma Radiation Loop Accuracy," Revision 0 remained within the acceptance criteria of Regulatory Guide 1.97, Criteria for Accident Monitoring Instrumentation for Nuclear Power Plants, as committed to within LA-RR-201.7-36C. Therefore, the inspectors concluded that the performance deficiency could not be considered a precursor to a significant event, it would not have potential to lead to a more significant safety concern if left uncorrected, and no cornerstone objective was meaningfully impacted.

This minor performance deficiency and violation closes URI 05000220/2025002-01. The inspectors note that this URI was initially opened as05000410/2025002-01, but the number has been updated to correctly align with the Nine Mile Point Unit 1 docket number, 05000220.

Corrective Action Reference(s): IRs 04872407 and 04891925

Minor Violation 71152A Minor Violation: The inspectors reviewed corrective actions taken in response to a fuel pin failure that occurred on October 28, 2024, during Cycle 26 at Unit 1, as well as the circumstances leading up to the failure. Specifically, the inspectors reviewed corrective action documents, including a root cause evaluation (RCE), generated by Constellation under IR 04812662. Additionally, the details and associated RCE in IR 04547699, related to a similar fuel failure that occurred on January 9, 2023, during Cycle 25, were considered by inspectors due to the similarities in circumstances that led to the fuel failures. The inspectors noted that the corrective actions taken for each event included revisions to multiple procedures related to core reload analysis and fuel cycle operational planning, execution, and risk assessment. While two fuel failures occurred in back-to-back cycles and were ultimately caused by the same fuel pellet-clad interaction (PCI) phenomenon in high residence time fuel bundles near the end of the cycles, the inspectors noted that the core fuel loading for Cycle 26 was in place and operating before corrective actions associated with the Cycle 25 failure could be established. Therefore, both cycles were susceptible to the same PCI failure mechanism, which is inherently stochastic in nature. In these circumstances, performance of a detailed PCI risk assessment is appropriate to inform fuel loading and operational decisions to ensure that excessive risk is not created due to a specific loading or operational strategy.

This is reflected in Electric Power Research Institute (EPRI) fuel reliability guidance (FRG) on PCI, which strongly recommends that a comprehensive PCI risk assessment be performed every cycle.

The inspectors noted that, prior to Nine Mile Point Unit 1 Cycle 23, comprehensive PCI risk assessments were performed for Unit 1 every cycle, following the EPRI FRG PCI recommendations, as required by CENG procedure CNG-FM-1.01-1000 and Nine Mile Point procedure GAP-NFM-01, which were effective at that time. However, the assessments were discontinued following a company merger that introduced a new management model, after which NFAA100, Reload Control Procedure, along with its associated sub-procedures, superseded the previous procedures. In the time since, evolutionary changes in fuel reload design and analysis and cycle operation strategies were implemented, which eroded margins to PCI failure.

The inspectors determined that Constellation not maintaining adequate procedural guidance for reload and cycle operation, specifically for management of risk associated with PCI, was a performance deficiency within Constellations ability to foresee and correct, and should have been prevented. Specifically, Revision 13 to Constellations procedure NF-AA-100-1600, "Reload and Cycle Operation Risk Management Assessment Instructions," did not provide adequate instructions to direct the nuclear fuels group to request detailed quantitative assessments of PCI risk from the fuel vendor, which allowed increased PCI risk to go unrecognized, contributing to PCI fuel failures that occurred on January 9, 2023, and October 28, 2024.

This procedural inadequacy constituted a violation of Nine Mile Point Unit 1 TS 6.4.1, "Procedures," which requires, in part, that procedures shall be established, implemented, and maintained that meet or exceed the requirements and recommendations of sections 5.1 and 5.3 of ANSI N18.7-1972 and cover the applicable procedures recommended in Regulatory Guide 1.33, Appendix A, dated November 3, 1972, which includes general plant operating procedures for changing load and load follow, power operation and process surveillance, and preparation for refueling and core alterations.

Screening: The inspectors determined the performance deficiency was minor. The inspectors screened this performance deficiency in accordance with IMC 0612, Appendix B, "Issue Screening," and determined that the performance deficiency was minor. Specifically, the inspectors determined that the individual fuel failure in each cycle could not be viewed as a precursor to a significant event, did not have the potential to lead to a more significant safety concern, and did not impact the Barrier Integrity cornerstone objective of ensuring that physical design barriers (i.e. cladding) protect the public from radionuclide releases caused by accidents or events. The inspectors noted that, while the cladding of an individual fuel pin was affected, the overall safety function of the fuel cladding barrier throughout the core was not meaningfully impacted, and that it maintained its ability to protect the public from radionuclide releases caused by accidents or events.

Enforcement:

This failure to comply with Nine Mile Point Unit 1 TS 6.4.1 constitutes a minor violation that is not subject to enforcement action in accordance with the NRCs Enforcement Policy. The failed fuel was identified, and local power was suppressed by inserting surrounding control rods. Additionally, Unit 1 power was reduced for the remainder of the cycle to prevent any further fuel integrity challenges. The affected fuel bundle was replaced during the subsequent core reload. The core reload plan for the next operating cycle was revised, and procedure enhancements were implemented to correct the procedure inadequacy under IR 04812871.

Minor Violation 71152S Minor Violation: A maintenance staff member at Nine Mile Point worked beyond the required rest period on November 20, 2025, and November 21, 2025, without a 34 hour3.935185e-4 days <br />0.00944 hours <br />5.621693e-5 weeks <br />1.2937e-5 months <br /> break as required by LS-AA-119, Fatigue Management and Work Hour Limits, Revision 17, section 5.1.1 and 10 CFR 26.205(d)(2)(ii).

Upon station management discovering the work hour rule violation, the issue was entered into the corrective action program as IR 04916794. A station stand down was performed with all staff to review the event and causes, and the individuals qualifications were removed. The individual and the supervisor failed to adequately verify compliance with work hour rules prior to work being conducted. The individual was conducting troubleshooting associated with Unit 2 containment radiation monitor 2CMS*CAB10A. The station reviewed the work the individual performed on November 20 and 21, 2025. Another qualified technician was present with the individual during the troubleshooting. The station determined there was no impact on the Unit 2 containment radiation monitor from the work performed by the individual. The inspectors review of equipment performance following the maintenance by the staff member determined that the equipment was not adversely impacted. The inspectors also identified a trend associated with human performance issues. In addition to the work hour rule violation, issues included the following:

1. On October 16, 2025, a Unit 2 equipment operator experienced an eye injury from

resin during a changeout. (IR 04906406)

2. On October 30, 2025, an instrument maintenance staff member overextended a

vibration probe into a fan motor housing causing the probe to be damaged. (IR 04910357)

3. On November 13, 2025, an instrument maintenance staff member failed to follow a

procedure which resulted in actuation of a fire sprinkler system and a station transient.

(IR 04914606)

Constellation generated IR 04920594 to address the trend, and develop a cause evaluation and detailed plan to improve site maintenance performance to prevent future occurrences.

Screening: The inspectors reviewed the NRC Enforcement Policy examples for significance.

Section 6.14.d.3 for potential Severity Level IV violations states, failures to appropriately implement any requirements of 10 CFR Part 26, Subpart I that do not result in an actual event or a degradation of a level of safety but are more than minor in that they are not isolated or demonstrate programmatic weaknesses in implementation. The inspectors determined that because the violation was an isolated occurrence and was not indicative or a programmatic weakness in implementation, the issue was minor.

The inspectors evaluated each of the human performance events noted in the trend above for significance in accordance with the guidance in IMC 0612, Appendix B, Issue Screening, and Appendix E, Examples of Minor Issues, and determined them to be minor, with the exception of issue 2, which is documented in this inspection report as a Green finding and associated NCV.

Enforcement:

10 CFR 26.205(d) states in part, licensees shall ensure that individuals have, at a minimum, the rest breaks specified in this paragraph. 10 CFR 26.205(d)(2)(ii) requires a 34 hour3.935185e-4 days <br />0.00944 hours <br />5.621693e-5 weeks <br />1.2937e-5 months <br /> break in any 9-day period.

Constellation procedure LS-AA-119, Fatigue Management and Work Hour Limits, section 5.1.1 provides the requirement to ensure a 34 hour3.935185e-4 days <br />0.00944 hours <br />5.621693e-5 weeks <br />1.2937e-5 months <br /> break is taken in any 9-day period.

Contrary to this requirement, on November 20, 2025, and November 21, 2025, a maintenance staff member worked beyond the required rest period.

The failure to comply with 10 CFR 26.205(d)(2)(ii) constitutes a minor violation that is not subject to enforcement action in accordance with the NRCs Enforcement Policy.

Fire Detector Initiation Causes Unit 2 Station Transient Cornerstone Significance Cross-Cutting Aspect Report Section Initiating Events

Green NCV 05000410/2025004-01 Open/Closed

[H.12] - Avoid Complacency 71153 A self-revealed Green finding and associated NCV of Nine Mile Point Unit 2 TS 5.4.1(a),

Procedures, was identified when the licensee failed to follow a procedure during a Unit 2 fire system test. Specifically, while performing fire detector testing, a technician failed to follow a caution statement as well as component identification and verification leading to an inadvertent initiation of the fire suppression system. The initiation led to a trip of the A condensate pump and a station transient.

Description:

Nine Mile Point Unit 2 utilizes a fire protection system to detect and provide a reliable, readily available source of water for controlling and extinguishing fires. The fire protection system utilizes detectors that monitor locations around the plant and will automatically actuate the fire protection water system. One feature the fire protection water system utilizes is a sprinkler suppression system. These sprinkler systems are located around general areas and around specific pieces of equipment that pose a higher fire risk. When actuated, these sprinkler systems will spray water to suppress and attempt to put out a fire in the detected area.

On November 13, 2025, maintenance technicians were performing a test of the fire detection system as part of N2-ISP-FPM-A114, Functional Test of The Fire Detection Zones For 2FPM-PNL-114, Revision 00600. At 1:34 PM, a technician actuated an incorrect detector that resulted in an unintended fire suppression system sprinkler actuation. The spray system wetted numerous electrical components and caused an electrical fault in the A condensate pump motor. This fault caused the A condensate pump to trip followed by a trip of the A condensate booster pump and B reactor feedwater pump. As a result of the pump trips and operator action, power was reduced to 42 percent.

Following the event on November 13, 2025, Constellation performed a Human Performance Review Board. The station determined the technicians failed to follow a caution statement in the procedure and initiated the wrong detector.

Procedure HU-AA-101, Human Performance Tools and Verification Practices, section 4.6.2 requires performing a verification on systems that could result in an immediate and irrecoverable threat to safe and continuous operation. Procedure N2-ISP-FPM-A114, Step 6.6, incorporates a caution statement that would prevent the technician from testing the wrong detector. The technician did not utilize the procedure while performing the test and instead used an incorrectly marked drawing for the detector that was to be tested.

Corrective Actions: Following the events on November 13, 2025, the station removed associated technician qualifications, implemented 100 percent supervisory oversight for all work performed in the plant, distributed a human performance alert to site personnel to share learnings and event consequences, conducted a station standdown, and replaced the A condensate pump motor.

Corrective Action References: IRs 04914567 and 04914606

Performance Assessment:

Performance Deficiency: The failure to follow a procedure and adequately verify the correct detector during a fire system test was a performance deficiency within Constellations ability to foresee and correct. Specifically, technicians failed to follow procedures HU-AA-101 and N2-ISP-FPM-A114 during fire suppression system testing.

Screening: The inspectors determined the performance deficiency was more than minor because it was associated with the Human Performance attribute of the Initiating Events cornerstone and adversely affected the cornerstone objective to limit the likelihood of events that upset plant stability and challenge critical safety functions during shutdown as well as power operations. Specifically, while performing a test of the fire detection system, a technician actuated an incorrect detector that resulted in a sprinkler activation in the wrong area, a trip of the A condensate pump, and a station transient.

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 determined that this finding was of very low safety significance (Green) by answering No to the question in Exhibit 1, associated with transient initiators because the event did not cause a reactor trip and the loss of mitigation equipment.

Cross-Cutting Aspect: H.12 - Avoid Complacency: Individuals recognize and plan for the possibility of mistakes, latent issues, and inherent risk, even while expecting successful outcomes. Individuals implement appropriate error reduction tools. Specifically, while performing testing on fire detectors, a technician failed to use human error reduction techniques such as equipment verification as described in HU-AA-101. As a result, a technician actuated an incorrect detector that resulted in a sprinkler activation in the wrong area, a trip of the A condensate pump, and a station transient.

Enforcement:

Violation: Nine Mile Point Unit 2 TS 5.4.1(a), Procedures, requires in part, that written procedures shall be established, implemented, and maintained covering the activities referenced in Regulatory Guide 1.33, Revision 2, Appendix A, dated November 1978.

Appendix A, section 8 states, in part, that specific procedures for control of measuring and test equipment and for surveillance tests, procedure, and calibrations should be written (implementing procedures are required for each surveillance test, inspection, or calibration listed in technical specification), which includes b(2)(h) Fire Protection System Functional Test.

Contrary to the requirements of HU-AA-101, on November 13, 2025, a technician failed to perform a component verification with the approved procedure and instead used an incorrectly marked drawing leading to the initiation of the incorrect detector. Specifically, while performing fire detector testing, a technician failed to follow a caution statement as well as component identification and verification leading to an inadvertent initiation of the fire suppression system. The initiation led to a trip of the A condensate pump and station transient.

Enforcement Action: This violation is being treated as an NCV, consistent with Section 2.3.2 of the Enforcement Policy.

EXIT MEETINGS AND DEBRIEFS

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

• On January 22, 2026, the inspectors presented the integrated inspection results to Tim Peter, Site Vice President, and other members of the licensee staff.

• On December 4, 2025, the inspectors presented the radioactive solid waste inspection results to Nick Tryt, Maintenance Director, and other members of the licensee staff.

• On February 4, 2026, the inspectors presented the Unit 1 containment high range radiation monitor URI closeout inspection results to Denise Wolniak, Senior Manager Regulatory and Learning Programs, and other members of the licensee staff.

THIRD PARTY REVIEWS

The inspectors reviewed the 2025 Institute of Nuclear Power Operations evaluation report that was issued in August 2025.

DOCUMENTS REVIEWED

Inspection

Procedure

Type

Designation

Description or Title

Revision or

Date

71111.01

Corrective Action

Documents

04445508

Procedures

N1-OP-64

Meteorological Monitoring

2100

N2-OP-102

Meteorological Monitoring

2800

Work Orders

69388336

69397342

71111.04

Procedures

N2-OP-100A-

LINEUPS

Standby Diesel Generators - Lineups

006

N2-OP-61B-

LINEUPS

Standby Gas Treatment System - Lineups

001

71111.05

Corrective Action

Documents

04883680

Fire Plans

N1-PFP-0101

Unit 1 Pre-Fire Plans

008

N2-FPI-PFP-0201 Unit 2 Pre-Fire Plans

71111.12

Corrective Action

Documents

04755109

04803795

04891515

04900510

Procedures

ER-AA-320

Maintenance Rule implementation per NEI 18-10

ER-AA-320-1004

Maintenance Rule - (a)(1) and (a)(2) Requirements

N1-OP-10

Reactor Building Heating, Cooling, and Ventilating System

033

71111.15

Corrective Action

Documents

04901255

04903089

71111.24

Corrective Action

Documents

04905778

04906188

Procedures

N1-ST-Q1D

CS [core spray] 122 Pump and Valve Operability Test

28

Inspection

Procedure

Type

Designation

Description or Title

Revision or

Date

N2-OSP-EGS-

M@001

Diesel Generator and Diesel Air Start Valve Operability Test -

Divisions I and II

26

N2-OSP-ICS-

Q@002

RCIC Pump and Valve Operability Test and System Integrity

Test and ASME XI Functional Test and Analysis

21

Work Orders

05715383

2599827

2619514

71151

Miscellaneous

N1-MSPI-001

Nine Mile Point Unit 1 MSPI Basis Document

N2-MSPI-001

Nine Mile Point Unit 2 MSPI Basis Document

17