RS-25-080, Relief Request 14R-15 for Extension of IWL-2410 Concrete Inspections, Fourth Inservice Inspection Interval
| ML25108A048 | |
| Person / Time | |
|---|---|
| Site: | LaSalle  |
| Issue date: | 04/17/2025 |
| From: | Steinman R Constellation Energy Generation |
| To: | Office of Nuclear Reactor Regulation, Document Control Desk |
| References | |
| RS-25-080 | |
| Download: ML25108A048 (1) | |
Text
4300 Winfield Road Warrenville, IL 60555 630 657 2000 Office April 17, 2025 10 CFR 50.55a RS-25-080 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D.C. 20555-0001
Subject:
LaSalle County Station, Unit 1 Renewed Facility Operating License No. NPF-11 NRC Docket No. 50-373 Relief Request I4R-15 for Extension of IWL-2410 Concrete Inspections, Fourth Inservice Inspection Interval In accordance with 10 CFR 50.55a(z)(1), Constellation Energy Generation, LLC (CEG) requests NRC approval of a proposed alternative to the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code,Section XI Examination Category L-A, for containment concrete surfaces as outlined in Table IWL-2500, as required and conditioned by 10 CFR 50.55a(g)(6)(ii)(B) on the basis that the alternative provides acceptable level of quality and safety for LaSalle County Station, Unit 1 (LSCS). The duration of this request is the remainder of the current Fourth Inservice Inspection (ISI) Interval/Third Containment Inservice Inspection (CISI) for LSCS Unit 1.
Specifically, CEG is requesting an alternative to the visual examination requirements of containment concrete surfaces. LSCS Unit 1 containment design is such that certain areas can only be accessed during an outage and entry at power is considered inaccessible due to operational or radiological restrictions that does not allow visual examination.
CEG proposes a one-time extension to the IWL concrete surface inspection to extend the current 5-year inspection by 6 months and requests approval of the proposed alternative by September 12, 2025. The proposed alternative for LSCS Unit 1 is provided in Attachment 1.
There are no regulatory commitments contained within this letter.
April 17, 2025 U.S. Nuclear Regulatory Commission Page 2 Should you have any questions concerning this letter, please contact Mrs. Danii Gantt at 779-231-6227.
Respectfully, Rebecca L. Steinman Sr. Manager Licensing Constellation Energy Generation, LLC
Attachment:
10 CFR 50.55a(z)(1) Proposed Alternative for Inservice Inspection Concrete Inspection Extension cc:
Regional Administrator - NRC Region III NRC Senior Resident Inspector - LaSalle County Station Illinois Emergency Management Agency and Office of Homeland Security-Division of Nuclear Safety
- Steinman, Rebecca Lee Digitally signed by Steinman, Rebecca Lee Date: 2025.04.17 22:05:09
-05'00'
Page 1 of 3 Attachment 10 CFR 50.55a(z)(1) Proposed Alternative for Inservice Inspection Concrete Inspection Extension Relief Request I4R-15 Proposed Alternative In accordance with 10 CFR 50.55a(z)(1)
Alternative Provides Acceptable Level of Quality and Safety
- 1. ASME Code Component(s) Affected Code Class:
Reference:
IWL-2410(a), IWL-2410(c)
Examination Category:
L-A Item Number:
L1.10
==
Description:==
Unit 1 Containment Concrete Surfaces
2. Applicable Code Edition and Addenda
The Unit 1 Third Containment Inservice Inspection (CISI) Interval Program is based on the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code,Section XI, 2007 Edition with 2008 Addenda. The Unit 1 Third CISI Interval, under the Fourth Inservice Inspection (ISI) Interval, began on October 1, 2017 and is currently scheduled to end on September 30, 2027.
3. Applicable Code Requirement
IWL-2410(a) requires that Concrete shall be examined in accordance with IWL-2510 at 1, 3, and 5 years following the completion of the containment Structural Integrity Test CC-6000 and every 5 years thereafter. The initial IWL-2410 containment concrete examinations at LaSalle County Station (LSCS) Unit 1 were completed on September 15, 1999, and this date has been used for scheduling subsequent IWL-2410 examinations, as permitted by 10 CFR 50.55a(g)(6)(ii)(B)
[61 FR 41303]. IWL-2410(c) requires that The 10 year and subsequent examinations shall commence not more than 1 year prior to the specified dates and shall be completed not more than 1 year after such dates. If plant operating conditions are such that examination of portions of the concrete cannot be completed within this stated time interval, examination of those portions may be deferred until the next regularly scheduled plant outage.
4. Reason for Request
IWL-2410 concrete examinations are required to be completed between September 15, 2023 and September 15, 2025. There are certain areas with restricted access during online operation that have not yet been examined during this examination period, such as:
1.
Areas of the Containment Drywell Floor and Reactor Vessel Pedestal 2.
Areas in the Outboard Main Steam Isolation Valve Room 3.
Areas in the vicinity of the Control Rod Drive Hatch 4.
Areas in the vicinity of the Equipment Hatch 5.
Areas in the vicinity of the NW & SE Suppression Pool Shield Doors
Page 2 of 3 Attachment 10 CFR 50.55a(z)(1) Proposed Alternative for Inservice Inspection Concrete Inspection Extension These surface areas are considered inaccessible during plant operation due to operational or radiological restrictions and can only be examined during a refueling outage. Due to scheduling errors, the inspections were not performed during the previous Unit 1 Refueling Outage (L1R20) in early 2024.
5. Proposed Alternative and Basis for Use
Constellation proposes a one-time extension of the end date of the 2-year examination period from September 15, 2025 to March 15, 2026 to perform the IWL-2510 examinations of the surface areas identified above during the Unit 1 Refueling Outage (L1R21) in early 2026. The only window of opportunity to access these areas for examination during the current 2-year examination period (without adverse risk to personnel safety) was during the Unit 1 refueling outage in February 2024 (L1R20). The next available opportunity to perform these examinations will be during the February 2026 Refueling Outage (L1R21), 5 months after the 2-year examination period ends on September 15, 2025.
The majority of the Unit 1 containment concrete surface areas requiring examination in accordance with IWL-2510 are accessible during plant operation and these examinations have been completed or will be completed prior to the end of the 2-year examination period on September 15, 2025.
There are no current degraded conditions being tracked for those concrete surface areas for which an extension is being requested. The drywell floor is walked down and inspected by plant personnel at the end of each refueling outage. In addition, an inspection of the interface between the metallic liner and drywell floor was performed during Refueling Outage L1R20 in 2024 by a civil engineer holding a professional license in the State of Illinois. This inspection did not identify any adverse conditions.
A one-time, 6-month extension to the 2-year examination period required by IWL-2410(c) will have an insignificant effect on the aging management of the LSCS concrete containment. For this reason, the proposed alternative provides an acceptable level of quality and safety. This issue has been entered into the site Corrective Action Program, and actions have been taken to ensure that subsequent IWL-2510 examinations will be scheduled as necessary to ensure completion on September 15, 2029 (+/- 1-year) and every 5 years thereafter.
6. Duration of Proposed Alternative
The proposed alternative is requested for use during the LSCS Unit 1 Fourth ISI/Third CISI Interval.
- 7. Precedent Letter from NRC to Entergy Nuclear Operation, Inc, Indian Point Nuclear Generation Unit No. 3 - Issuance of Relief Request IP3-ISI-RR Alternative to Certain Requirements of the ASME Code for Extension of the Fourth 10-year Inservice Inspection Interval (EPID L-2017-LLR-0128), dated July 18, 2018 (ADAMS Accession No. ML17297A455).
- 8. References 8.1 LaSalle County Generating Station, Units 1 & 2, ISI Program Plan, Fourth Ten-Year Inspection Interval.
Attachment 10 CFR 50.55a(z)(1) Proposed Alternative for Inservice Inspection Concrete Inspection Extension Page 3 of 3 8.2 American Society of Mechanical Engineers Boiler and Pressure Vessel Code,Section XI, Division 1, 2007 Edition with the 2008 Addenda.