IR 05000298/2025004
| ML26034C371 | |
| Person / Time | |
|---|---|
| Site: | Cooper  |
| Issue date: | 02/11/2026 |
| From: | Douglas Dodson NRC/RGN-IV/DORS/PBC |
| To: | Dia K Nebraska Public Power District (NPPD) |
| References | |
| IR 2025004, IR 2025001 | |
| Download: ML26034C371 (0) | |
Text
February 11, 2026
SUBJECT:
COOPER NUCLEAR STATION - INTEGRATED INSPECTION REPORT 05000298/2025004 AND INDEPENDENT SPENT FUEL STORAGE INSTALLATION REPORT 07200066/2025001
Dear Khalil Dia:
On December 31, 2025, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection at Cooper Nuclear Station. On January 22, 2026, the NRC inspectors discussed the results of this inspection with Justin Reimers, General Manager Plant Operations, 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, Douglas E. Dodson II, Chief Reactor Projects Branch C Division of Operating Reactor Safety Docket Nos. 05000298 and 07200066 License No. DPR-46
Enclosure:
As stated
Inspection Report
Docket Number:
05000298 and 07200066
License Number:
Report Number:
05000298/2025004 and 07200066/2025001
Enterprise Identifier:
I-2025-004-0007 and I-2025-001-0013
Licensee:
Nebraska Public Power District
Facility:
Cooper Nuclear Station
Location:
Brownville, NE
Inspection Dates:
October 1, 2025, to December 31, 2025
Inspectors:
B. Baca, Health Physicist
G. Birkemeier, Resident Inspector
L. Brookhart, Senior Spent Fuel Storage Inspector
G. Kolcum, Senior Resident Inspector
K. Murphy, Operations Engineer
R. Williams, Operations Engineer
Approved By:
Douglas E. Dodson II, Chief
Reactor Projects Branch C
Division of Operating Reactor Safety
SUMMARY
The U.S. Nuclear Regulatory Commission (NRC) continued monitoring the licensees performance by conducting an integrated inspection at Cooper Nuclear Station 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
Cooper Nuclear Station began the inspection period at rated thermal power. On October 11, 2025, reactor power was reduced to 80 percent due to grid demand. The unit returned to rated thermal power on October 12, 2025. On November 7, 2025, reactor power was reduced to 70 percent for a planned rod sequence exchange. The unit returned to rated thermal power on November 8, 2025. On November 10, 2025, reactor power was reduced to 75 percent for a planned rod sequence exchange. The unit returned to rated thermal power on November 10, 2025. The unit remained at 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, observed risk significant activities, and completed on-site portions of IPs. The inspectors reviewed selected procedures and records, observed activities, and interviewed personnel to assess licensee performance and compliance with Commission rules and regulations, license conditions, site procedures, and standards.
REACTOR SAFETY
71111.01 - Adverse Weather Protection
Seasonal Extreme Weather Sample (IP Section 03.01) (1 Sample)
- (1) The inspectors evaluated readiness for seasonal extreme weather conditions prior to the onset of seasonal cold temperatures for the following systems:
- supplemental diesel generator system, emergency diesel generators, and service water pumps on October 22, 2025
71111.04 - Equipment Alignment
Partial Walkdown Sample (IP Section 03.01) (1 Sample)
The inspectors evaluated system configurations during partial walkdowns of the following systems/trains:
(1)division 2 core spray on October 1, 2025
71111.05 - Fire Protection
Fire Area Walkdown and Inspection Sample (IP Section 03.01) (2 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)service water pump room and intake structure on November 5, 2025 (2)diesel generator building on December 4, 2025
71111.06 - Flood Protection Measures
Flooding Sample (IP Section 03.01) (1 Sample)
- (1) The inspectors evaluated internal flooding mitigation protections in the:
- control building basement on November 7, 2025
71111.11A - Licensed Operator Requalification Program and Licensed Operator Performance
Requalification Examination Results (IP Section 03.03) (1 Sample)
- (1) The inspectors reviewed and evaluated the licensed operator examination failure rates for the requalification annual operating exam administered from September 23, 2025, to October 31, 2025.
71111.11B - Licensed Operator Requalification Program and Licensed Operator Performance
Licensed Operator Requalification Program (IP Section 03.04) (1 Sample)
- (1) Biennial Requalification Written Examinations The inspectors evaluated the quality of the licensed operator biennial requalification written examination administered on November 12, 2025.
Annual Requalification Operating Tests The inspectors evaluated the adequacy of the licensees annual requalification operating test.
Administration of an Annual Requalification Operating Test The inspectors evaluated the effectiveness of the licensee in administering requalification operating tests required by 10 CFR 55.59(a)(2) and that the licensee is effectively evaluating their licensed operators for mastery of training objectives.
Requalification Examination Security The inspectors evaluated the ability of the 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 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) (1 Sample)
- (1) The inspectors observed and evaluated licensed operator performance in the control room during a quarterly rod pattern adjustment and scram time testing on November 8, 2025.
Licensed Operator Requalification Training/Examinations (IP Section 03.02) (1 Sample)
- (1) The inspectors observed and evaluated operations training simulator loss of offsite power/loss of one diesel on October 28, 2025.
71111.13 - Maintenance Risk Assessments and Emergent Work Control
Risk Assessment and Management Sample (IP Section 03.01) (3 Samples)
The inspectors evaluated the accuracy and completeness of risk assessments for the following planned and emergent work activities to ensure configuration changes and appropriate work controls were addressed:
(1)diesel generator 1 Yellow risk due to unplanned auto start during undervoltage relay test on October 6, 2025 (2)planned standby liquid control maintenance resulting in Yellow risk on October 15, 2025 (3)planned diesel generator 2 maintenance window resulting in Yellow risk on October 21, 2025
71111.15 - Operability Determinations and Functionality Assessments
Operability Determination or Functionality Assessment (IP Section 03.01) (1 Sample)
The inspectors evaluated the licensee's justifications and actions associated with the following operability determinations and functionality assessments:
(1)diesel generator 1 day tank leak at high level shutoff switch on October 1, 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) (3 Samples)
(1)control rod drive accumulator high water level for HCU 34-31 for corrective maintenance on October 1, 2025 (2)diesel generator 2 post-maintenance testing on October 24, 2025 (3)fire pump E maintenance on November 5, 2025
Surveillance Testing (IP Section 03.01) (4 Samples)
(1)fire pump D surveillance test on October 3, 2025 (2)alternate rod insertion and anticipated transient without scram reactor vessel high-pressure channel functional test on October 3, 2025 (3)undervoltage relay functional test on October 6, 2025 (4)low-pressure coolant injection train A surveillance test on November 6, 2025
OTHER ACTIVITIES - BASELINE
71151 - Performance Indicator Verification The inspectors verified licensee performance indicators submittals listed below:
BI01: Reactor Coolant System (RCS) Specific Activity Sample (IP Section 02.10) (1 Sample)
- (1) April 1, 2024, through March 31, 2025
BI02: RCS Leak Rate Sample (IP Section 02.11) (1 Sample)
- (1) April 1, 2024, through March 31, 2025
OR01: Occupational Exposure Control Effectiveness Sample (IP Section 02.15) (1 Sample)
- (1) July 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) July 1, 2024, through September 30, 2025 71152A - Annual Follow-up Problem Identification and Resolution
Annual Follow-up of Selected Issues (Section 03.03) (1 Sample)
The inspectors reviewed the licensees implementation of its corrective action program related to the following issues:
(1)diesel generator 1 unplanned automatic start during undervoltage relay test on October 6, 2025
71152S - Semiannual Trend Problem Identification and Resolution Semiannual Trend Review (Section 03.02) (1 Sample)
- (1) The inspectors reviewed the licensees corrective action program to identify potential trends in motor-operated valve position indications that might be indicative of a more significant safety issue.
OTHER ACTIVITIES
- TEMPORARY INSTRUCTIONS, INFREQUENT AND ABNORMAL 60855 - Operation of an Independent Spent Fuel Storage Installation The inspectors performed a review of the licensees independent spent fuel storage installation (ISFSI) activities to verify compliance with Certificate of Compliance (CoC) 72-1004, License Amendment 18, and the Orano TN NUHOMS Final Safety Analysis Report (FSAR),
Revision 22. The inspectors reviewed selected procedures, corrective action reports, and records to verify ISFSI operations were compliant with the license technical specifications, requirements in the FSAR, and NRC regulations.
Operation of an Independent Spent Fuel Storage Installation (1 Sample)
- (1) The inspectors evaluated the licensees dry cask storage program implementation during an in-office remote inspection from December 15-17, 2025. Due to the government shutdown that occurred during the quarter, regional inspectors were unable to observe the licensee's recent spent fuel loading campaign. The Cooper Station ISFSI pad was designed to store 52 Orano Transnuclear (TN) NUHOMS Horizontal Storage Modules (HSMs) using the 61BTH dry shielded canisters (DSCs)
(containing 61 boiling-water reactor spent fuel assemblies). At the time of the inspection, the licensee had 38 DSCs placed within the HSMs. NRC resident inspectors were utilized to conduct a physical walkdown of the ISFSI pad and surrounding area under the guidance and direction of regional ISFSI inspectors.
The inspectors reviewed related documents of the following activities during the inspection:
- walkdown of the ISFSI pad observing HSMs condition, radiological postings, and fire protection implementation
- fuel selection evaluations for the canisters loaded since the last NRC ISFSI inspection (canisters 31 - 38)
- radiation surveys for radiological dose at the owner-controlled area boundary to verify compliance with the requirements of 10 CFR 72.104 for 2020 through 2024
- selected ISFSI-related condition reports issued since the last NRC ISFSI inspection
- quality assurance program implementation, including recent audits, surveillances, receipt inspection, and quality control activities related to ISFSI operations
- compliance to technical specifications for operational surveillance activities and FSAR required maintenance activities
- documentation of annual maintenance activities for the cask handling crane and special lifting devices
- selected licensee design changes and program changes for the ISFSI performed under the 10 CFR 72.48 program
- changes made in the 10 CFR Part 72.212 Evaluation report from Revision 6 to Revision 8
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 16, 2025, the inspectors conducted a technical debrief for the licensed operator requalification exams with Khalil Dia, Site Vice President, and other members of the licensee staff.
- On December 18, 2025, the inspectors presented the ISFSI triennial inspection results to Bill Chapin, General Manager of Plant Operations, and other members of the licensee staff.
- On January 22, 2026, the inspectors presented the integrated inspection results to Justin Reimers, General Manager of Plant Operations, and other members of the licensee staff.
DOCUMENTS REVIEWED
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
Corrective Action
Documents
CR-CNS-
21-03087, 2022-01863, 2023-02807, 2024-00467, 2024-
03120, 2025-00490, 2025-02958, 2025-03100, 2025-03145,
25-03929, 2025-04131, 2025-04132, 2025-04248, 2025-
04342, 2025-04509, 2025-04512, 2025-04616, 2025-04617,
25-04686, 2025-04842
Engineering
Changes
PAD 162260,
PAD 202752
Dry Cask Storage Licensing Basis Implementation for
Changes to 72.212 Report
CFR 72.212
Report
Cooper ISFSI 72.212 Report
Certificate of
Conformance
DSC Spent Fuel Cask 31-38
Various
Dates
Engineering
Evaluations
NEDC 08-042
TN Transfer Cask and DSC Weights for Various Spent Fuel
Loading Configurations
08/25/2025
Miscellaneous
NUH-06-113.92
Equipment Use Certification
Procedures
6.LOG.61
Daily Surveillance Log - Modes 1, 2, and 3
Various
Dates
Radiation
Surveys
Environmental Radiological Operating Reports and Area
DLR Work Sheets for 2020-2024
Various
Dates
Audit Report 22-
NIOS Audit 22-04
Audit Report 24-
Surveillance
SS24-002
Orano TN Americas QA Surveillance
Self-Assessments
Surveillance
SS24-007
Orano TN Americas Surveillance Report
60855
Work Orders
0-CNS-FAP-WM-
016
Seasonal Reliability
Procedures
2.2.99
Supplemental Diesel Generator System
Drawings
2045, Sheet 1
Cooper Nuclear Station Flow Diagram
N58
Procedures
0.31
Equipment Status Control
101
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
2.2.9
Core Spray System
Drawings
CNS-FP-256
Intake Structure
FP-383
Fire Plans
Miscellaneous
NEDC 11-089
Fire Safety Analysis for Fire Area IS-A
Procedures
CNS-FP-236
0-Barrier-Misc, Miscellaneous Buildings
Miscellaneous
NEDC-09-102
Internal Flooding - HELB, MELB, and Feedwater Line Break
CR-CNS-2024-
00388 Root
Cause
Operations Medical Records Update Issue
2/29/2024
CR-CNS-2025-
2537
Licensed Operator Medical Restriction
05/27/2025
Corrective Action
Documents
LO 2024-0170
Assessment Report for the 2025 Licensed Operator
Requalification (LOR) Program Pre-IP71111.11 Assessment
06/24/2025
Summary of CRs Related to Operator Actions & Errors in the
Control Room
Plant Events and OE Summary
Operating Test - JPMs - Week 1 (5)
09/24/2025
Operating Test - Simulator Scenarios - Week 1 (3)
09/24/2025
Operating Test - Simulator Scenarios - Week 4
10/15/2025
Biennial Written Exam - SRO - Week 1
11/12/2025
Biennial Written Exam - RO - Week 1
11/12/2025
Licensed Operator Medical Records (9)
License Operator Reactivation Form (3)
Form 16
Examination Question and Comment Form
11/12/2025
OTH0151010
Medical ANSI Standards Power Point
Miscellaneous
TABLE 03.03-1
from IP 71111.11
Examination Results - Written and Operating Test
2/16/2025
Procedures
NTP8.1
Administration of Licensed Operator Medical Examination
Program
07/23/2025
Miscellaneous
CR-CNS-
25-05097, 2025-05099, 2025-05100, 2025-05101, 2025-
05102, 2025-05103, 2025-05104, 2025-05105
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
10.9
Nuclear Performance, Control Rod Scram Time Evaluation
2.0.1
Plant Operations Policy
2.1.10
Station Power Changes
28
2.2.19
480 VAC Auxiliary Power Distribution System
5.3AC480
480 VAC Bus Failure
5.3EMPOWER
Emergency Power During Mode 1, 2, or 3
Procedures
6.RPS.302
Main Turbine Stop Valve Closure and Steam Valve
Functional Test
Corrective Action
Documents
CR-CNS-
25-04649
Protected Equipment Tagout SLC-1-SLC-P-A, Week 2541
Miscellaneous
Protected Equipment Tagout DGB-1-DG2, Week 2516
Procedures
6.1EE.306
4160V Bus 1F Undervoltage Relay Channel Functional Test
Corrective Action
Documents
CR-CNS-
25-04578
Procedures
6.DG.602
Diesel Fuel Oil Availability
Work Orders
Corrective Action
Documents
CR-CNS-
25-04575, 2025-04595, 2025-04649, 2025-04848, 2025-
04856, 2025-04861, 2025-04866, 2025-04867, 2025-04872,
25-04885, 2025-04888, 2025-04890, 2025-04893, 2025-
04897
Miscellaneous
ARI and ATWS/RPT Reactor Vessel High Pressure Channel
Functional Test
6.FP.102
Station Fire Pump Surveillance Testing
2.28
Control Rod Drive Hydraulic System
24
6.1RHR101
RHR Test Mode Surveillance Operation (IST)(DIV 1)
Procedures
6.FP.101
Fire Pump Functionality Test
Work Orders
WO 5401062, 5476817, 5497489, 5497853, 5516744, 5520152
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
Corrective Action
Documents
CR-CNS-2024-
4656
Worker Received Dose Rate Alarm
10/16/2024
Performance Indicator Verification Data Summary -
July 2024 through September 2025
25 Year to Date Gaseous Effluent Dose Calculations:
January through September 2025
71151
Miscellaneous
N1S2025022
Cooper Nuclear Station Annual Radioactive Effluent Release
Report
04/25/2025
Corrective Action
Documents
CR-CNS-
25-04649
Procedures
6.1EE.306
4160V Bus 1F Undervoltage Relay Channel Functional Test
(DIV 1)
Corrective Action
Documents
CR-CNS-
25-01713