ML25339A000
| ML25339A000 | |
| Person / Time | |
|---|---|
| Site: | Callaway  |
| Issue date: | 12/08/2025 |
| From: | Greg Warnick NRC/RGN-IV/DORS/EB2 |
| To: | Karenina Scott Ameren Missouri |
| References | |
| IR 2025011 | |
| Download: ML25339A000 (0) | |
Text
December 08, 2025 Kent Scott, Senior Vice President and Chief Nuclear Officer Union Electric Company Ameren Missouri 8315 County Road 459 Steedman, MO 65077
SUBJECT:
CALLAWAY PLANT - LICENSEE RENEWAL REPORT 05000483/2025011
Dear Kent Scott:
On December 3, 2025, the U.S. Nuclear Regulatory Commission (NRC) completed an in-office inspection at Callaway Plant and discussed the results of this inspection with Todd Witt, Director, Nuclear Engineering Design and Regulatory Affairs 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, Gregory G. Warnick, Chief Engineering Branch 2 Division of Operating Reactor Safety Docket No. 05000483 License No. NPF-30
Enclosure:
As stated cc w/encl: Distribution via LISTSERV Signed by Warnick, Gregory on 12/08/25
SUNSI Review By: GAP
Non-Sensitive
Sensitive
Publicly Available
Non-Publicly Available OFFICE SRI:DORS/EB2 C:DORS/EB2 NAME GPick GWarnick SIGNATURE
/RA/
/RA/
DATE 12/05/25 12/08/25
Enclosure U.S. NUCLEAR REGULATORY COMMISSION Inspection Report Docket Number:
05000483 License Number:
NPF-30 Report Number:
05000483/2025011 Enterprise Identifier:
I-2025-011-0037 Licensee:
Union Electric Company Ameren Missouri Facility:
Callaway Plant Location:
Steedman, MO Inspection Dates:
December 1, 2025 - December 3, 2025 Inspectors:
G. Pick, Senior Reactor Inspector Approved By:
Gregory G. Warnick, Chief Engineering Branch 2 Division of Operating Reactor Safety
2
SUMMARY
The U.S. Nuclear Regulatory Commission (NRC) continued monitoring the licensees performance by conducting a licensee renewal inspection at Callaway Plant, 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.
3 INSPECTION SCOPES This inspection was conducted using the appropriate portions of the inspection procedures in effect at the beginning of the inspection unless otherwise noted. Currently approved inspection procedures 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 inspection program requirements most appropriate to the inspection activity were met consistent with Inspection Manual Chapter 2515, Light-Water Reactor Inspection Program - Operations Phase. The inspector 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.
OTHER ACTIVITIES - TEMPORARY INSTRUCTIONS, INFREQUENT AND ABNORMAL 71003 - Post-Approval Site Inspection for License Renewal Phase 3 Inspection activities are performed after the licensee enters the period of extended operation. The period of extended operation is an additional 20 years beyond the original 40-year licensed term. Callaway Plant began the period of extended operation on October 18, 2024.
The inspector performed this in-office inspection to evaluate whether the licensee completed outstanding actions required to comply with the license renewal license condition and commitments and effectively implemented outstanding actions related to aging management programs.
During this in-office inspection, the inspector evaluated the licensee actions related to commitments not closed during the Phase 2 license renewal inspection (Inspection Report 05000483/2024011 (ML24117A310)).
The inspector reviewed program documents, inspection results, licensing correspondence, engineering reports, and corrective action documents. The inspector interviewed the program owners to discuss the technical resolution related to the commitments.
The inspector closed Commitments 32 and 45 and their associated aging management programs during this inspection.
Post-Approval Site Inspection for License Renewal (2 Samples)
(1) 19.1.31 Structures Monitoring (XI.S6) and Commitment 45 This existing inspection and monitoring program manages the effects of aging for concrete elements, structural steel, roof systems, masonry walls and metal siding, non ASME mechanical supports, and electrical supports. The licensee included the required inspections of their masonry walls and water control structures aging management programs as part of this program. The program manages the following aging effects for in-scope structures and structural elements: concrete cracking and spalling, cracking and distortion, cracking with loss of material, cracking with loss of bond or loss of material, increase in porosity and permeability, loss of strength, loss of material, loss of mechanical function, loss of sealing, and reduction in concrete anchor capacity.
4 Commitment 45 specified:
Enhance the regulatory guide 1.127, Inspection of Water-Control Structures Associated with Nuclear Power Plants, program and procedures to include the concrete structures in the turbine building that provide a flow path for the circulating water system in the scope of the program.
During the last inspection, the inspector identified that the licensee had not monitored the concrete tunnels (also known as vaults) below the turbine building that provided a return path for circulating water because they considered them inaccessible. The inspector determined that the licensee could access the vault during outages when operations secure circulating water flow to clean the cooling tower basin.
During this inspection, the inspector determined that the licensee had inspected the vaults. The inspector reviewed the vault inspection report including photographs of the concrete condition. After 40 years the inspection identified that the concrete remained in good condition with surface level cracking, flaking/spalling, minor aggregate popouts, and joint overpour. The licensee planned to implement future inspections at the same frequency of other structural inspections.
Based on the review of the procedures, work orders, the inspection report, and discussions with licensee personnel, the inspector did not identify any findings or violations associated with this aging management program.
(2) 19.2.3 Concrete Containment Tendon Prestress Program (X.S1) and Commitment 32 This existing program, which is part of the ASME section XI, subsection IWL inservice inspection program, manages loss of tendon prestress consistent with the requirements of 10 CFR 50.55a(b)(2)(viii)(B).
Commitment 32 specified:
Enhance the program to:
Include random samples for the 40-, 45-, 50-, and 55-year surveillances.
Extend the predicted lower limit lines for the vertical and hoop tendon groups to 60 years.
Require the final report for each surveillance interval to plot the measured results against time and to include the predicted lower limit, minimum required value, and trend lines.
Require a regression analysis consistent with the requirements of Information Notice 99-10, Degradation of Prestressing Tendon Systems in Prestressed Concrete Containments, revision 1, attachment 3, Comparison and Trending of Prestressing Forces.
During a previous inspection, the inspector did not close the commitment nor the aging management program because the licensee had not yet received a decision from NRC related to an associated relief request, which would delay the required 5-year testing for the 40-year inspection by another 5 years.
During this inspection, the inspector reviewed correspondence between the NRC and
5 the licensee. The inspector verified that the NRC had approved relief request C3R-01, Request for Relief from Requirements of ASME BPV Code,Section XI, Subsection IWL Regarding Examination and Testing of the Unbonded Post-Tensioning System. The NRC had granted this relief request as an one-time extension of the 40th year in the third interval to the 45th year. The licensee indicated that they planned to perform the examination in the summer of 2030.
Based on the review of the procedures, work orders and correspondence, and discussions with licensee personnel, the inspector did not identify any findings or violations associated with this aging management program.
INSPECTION RESULTS No findings were identified.
EXIT MEETINGS AND DEBRIEFS The inspector verified no proprietary information was retained or documented in this report.
On December 3, 2025, the inspector presented the license renewal inspection results to Todd Witt, Director, Nuclear Engineering Design and Regulatory Affairs and other members of the licensee staff.
6 NRC closed commitments: 3, 9, 20, 41, and 42 in Inspection Report 05000483/2023010.
NRC closed commitments: 1, 2, 4, 5, 6, 7, 8, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 33, 34, 35, 36, 37, 38, 39, 40, 43, 44, and 46 in Inspection Report 05000483/2024011 During this inspection, the inspectors closed commitments 32 and 45.
DOCUMENTS REVIEWED Inspection Procedure Type Designation Description or Title Revision or Date Corrective Action Documents CR-202401621, 202401988, 202401998, 202402035, 202402038, 202402039, 202402053, 202502696 Callaway Plant, Unit No. 1 - Supplemental Information Needed for Acceptance of Requested Licensing Action Re: Request for Relief from Requirements of ASME Code,Section XI, Subsection IWL Examination And Testing of the Unbonded Post-Tensioning System (EPID L-2023-LLR-0061) 12/14/2023 Reinforced Concrete Structures under the Turbine Building and in Yard Area 8/7/2025 Callaway Plant, Unit No. 1 - Regulatory Audit Summary Concerning Review of Request No. C3R-01 for Proposed Alternative to ASME Code, Section Xi Requirements for Containment Building Inspections (EPID L-2023-LLR-0061) 8/2/2024 Relief Request C3R-01 Callaway Plant, Unit No. 1 - Authorization and Safety Evaluation for Alternative Request C3R-01 (EPID L-2023-LLR-0061) 8/13/2024 71003 Miscellaneous ULNRC-06831 Request for Relief from Requirements of ASME BPV Code,Section XI, Subsection IWL Regarding Examination and Testing of the Unbonded Post-Tensioning System (Relief Request C3R-01) 10/26/2023 Miscellaneous ULNRC-06847 Supplement to Relief Request from Requirements of ASME BPV Code,Section XI, Subsection IWL Regarding Examination and Testing of the Unbonded Post-Tensioning System (Relief Request C3R-01) 12/21/2023 71003 Procedures ESP-EF-03002 Ultimate Heat Sink Retention Pond In-Service Inspection 8
7 ESP-ZZ-01013 Callaway Structures Inspection Program 12 Work Orders Job 24000980, 24002343, 24503571