IR 05000454/2025501
| ML25351A058 | |
| Person / Time | |
|---|---|
| Site: | Byron  |
| Issue date: | 12/18/2025 |
| From: | Michael Ziolkowski NRC/RGN-III/DRSS |
| To: | Mudrick C Constellation Energy Generation, Constellation Nuclear |
| References | |
| IR 2025501 | |
| Download: ML25351A058 (0) | |
Text
SUBJECT:
BYRON STATION - EMERGENCY PREPAREDNESS BIENNIAL EXERCISE INSPECTION REPORT 05000454/2025501 AND 05000455/2025501
Dear Christopher Mudrick:
On December 10, 2025, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection at Byron Station and discussed the results of this inspection with N. Burton 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, Michael E. Ziolkowski, Chief Security, Emergency Preparedness, and Incident Response Branch Division of Radiological Safety and Security Docket Nos. 05000454 and 05000455 License Nos. NPF-37 and NPF-66
Enclosure:
As stated
Inspection Report
Docket Numbers:
05000454 and 05000455
License Numbers:
Report Numbers:
05000454/2025501 and 05000455/2025501
Enterprise Identifier:
I-2025-501-0009
Licensee:
Constellation Energy Generation, LLC
Facility:
Byron Station
Location:
Byron, IL
Inspection Dates:
August 25, 2025, to December 10, 2025
Inspectors:
J. Kutlesa, Sr Emergency Preparedness Inspector
T. McGowan, Emergency Preparedness Inspector
Approved By:
Michael E. Ziolkowski, Chief
Security, Emergency Preparedness, and Incident Response Branch
Division of Radiological Safety and Security
SUMMARY
The U.S. Nuclear Regulatory Commission (NRC) continued monitoring the licensees performance by conducting an emergency preparedness biennial exercise inspection at Byron 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.
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
71114.01 - Exercise Evaluation
Inspection Review (IP Section 02.01-02.11) (1 Sample)
- (1) The licensee performed a biennial emergency preparedness exercise in accordance with 10 CFR 50 Appendix E(IV)(F)(2)(b), (c), and (j)(iii)(2). This exercise occurred on October 21, 2025, during the 2025 Government Shutdown and, as a result, the inspectors had to review all available documentation to support the evaluation of this exercise per IP 71114.01 and have determined that the licensee has complied with all applicable regulations.
71114.08 - Exercise Evaluation - Scenario Review
Inspection Review (IP Section 02.01 - 02.04) (1 Sample)
- (1) The inspectors reviewed and evaluated the proposed scenario for biennial emergency plan exercise on September 3,
OTHER ACTIVITIES - BASELINE
===71151 - Performance Indicator Verification The inspectors verified licensee performance indicators submittals listed below:
EP01: Drill/Exercise Performance (DEP) Sample (IP Section 02.12)===
- (1) October 1, 2024, through September 30, 2025 EP02: Emergency Response Organization (ERO) Drill Participation (IP Section 02.13) (1 Sample)
- (1) October 1, 2024, through September 30, 2025 EP04: Emergency Response Facility and Equipment Readiness (ERFER) (IP Section 02.14) (1 Sample)
- (1) January 1 through September 30,
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 emergency preparedness biennial exercise inspection results to N. Burton and other members of the licensee staff.
DOCUMENTS REVIEWED
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
25 EP Byron NRC Graded Exercise: TSC DCs
10/23/2025
25 EP Byron NRC Graded Exercise: OSC DCs
10/23/2025
25 EP Byron NRC Graded Exercise: SIM CR DCs
10/23/2025
25 EP Byron NRC Graded Exercise: EOF DCs
10/21/2025
Corrective Action
Documents
Resulting from
Inspection
25 EP Byron NRC Graded Exercise: JIC DCs
10/24/2025
Byron Draft AAR
20 2025
FEMA Byron Generating Station Radiological Emergency
Preparedness Exercise Radiological Emergency
Preparedness Program Draft After-Action
Report/Improvement Plan Exercise Date: October 21, 2025
11/20/2025
Miscellaneous
EP-MW-114-100-
F-01
Nuclear Accident Reporting System (NARS) Forms for Alert,
Site Area Emergency, and General Emergency
10/21/2025
Procedures
Radiological Emergency Plan Annex for Byron Station
Self-Assessments N/A
Byron 2025 NRC Graded Exercise Evaluation Report
11/25/2025
Addendum 3
Constellation Emergency Action Levels for Byron Station
Miscellaneous
Byron Station 2025 NRC Graded Exercise Manual
08/22/2025
Monthly Data Elements for NRC ROP Indicator - Emergency
Response Organization (ERO) Drill Participation
10/01/2024
through
09/30/2025
Monthly Data Elements for NRC ROP Indicator -
Drill/Exercise Performance
10/01/2024
through
09/30/2025
71151
Miscellaneous
Monthly Data Elements for NRC ROP Indicator - Emergency
Response Facility and Equipment Readiness (ERFER)
01/01/2025
through
09/30/2025