ML25267A007
| ML25267A007 | |
| Person / Time | |
|---|---|
| Site: | FitzPatrick  |
| Issue date: | 09/23/2025 |
| From: | Richard Guzman NRC/NRR/DORL/LPL1 |
| To: | Henry M Constellation Energy Generation |
| References | |
| EPID L-2025-LLA-0088 | |
| Download: ML25267A007 (1) | |
Text
From:
Rich Guzman To:
"Henry, Michael: (Constellation Nuclear)"
Cc:
"Hawes, Mark: (Constellation Nuclear)"
Bcc:
Rich Guzman
Subject:
James A. FitzPatrick - Request for Additional Information Re: LAR for Proposed Changes to the TSs - Primary Containment Isolation Instrumentation Tables and New Main Steam Tunnel Area Temperature Technical Specification 3.7.8 (EPID L-2025-LLA-0088)
Date:
Tuesday, September 23, 2025 12:02:00 PM
- Mike,
On September 4, 2025, the U.S. Nuclear Regulatory Commission (NRC) staff sent Constellation Energy Generation, LLC (CEG, the licensee) the subject Request for Additional Information (RAI) as a draft e-mail. This RAI supports the staffs review of the licensees May 29, 2025, license amendment request (LAR) (ML25149A172), for James A.
FitzPatrick Nuclear Power Plant (FitzPatrick). The proposed amendment would remove Function 1.e, Main Steam Line Tunnel Area Temperature - High, and insert the word "Deleted" in Table 3.3.6.1-1, Primary Containment Isolation Instrumentation. The proposed amendment would also add a new TS 3.7.8, Main Steam Tunnel (MST) Area Temperature.
The NRC staff and CEG held a conference call on September 10, 2025, to discuss clarifications on the draft RAI.Updated below is the official (final) RAI.As discussed on the call, please provide a response to this question within 45 days of this e-mail communication or no later than November 7, 2025. This email communication will be placed in ADAMS as an official agency record. Please contact me if you have any questions concerning this request.
Thank you,
Richard V. Guzman Senior Project Manager Plant Licensing Branch I Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Phone: (301) 415-1030 Richard.Guzman@nrc.gov
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REQUEST FOR ADDITIONAL INFORMATION LICENSE AMENDMENT REQUEST TO REVISE TECHNICAL SPECIFICATIONS PRIMARY CONTAINMENT ISOLATION INSTRUMENTATION TABLE AND NEW MAIN STEAM TUNNEL AREA TEMPERATURE CONSTELLATION ENERGY GENERATION, LLC JAMES A. FITZPATRICK NUCLEAR POWER PLANT DOCKET NO. 50-333
INTRODUCTION
By letter dated May 29, 2025 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML25149A172), Constellation Energy Generation, LLC (CEG, the licensee) submitted a license amendment request (LAR) for James A. FitzPatrick Nuclear Power Plant (FitzPatrick). The proposed amendment would remove Function 1.e, Main Steam Line Tunnel Area Temperature - High, inserts the word "Deleted" in Table 3.3.6.1-1 Primary Containment Isolation Instrumentation, and adds a new TS 3.7.8, Main Steam Tunnel (MST) Area Temperature.
REGULATORY BASIS
The regulation in Title 10 of the Code of Federal Regulations (10 CFR) Section 50.49 requires that electrical equipment important to safety be capable of performing their safety functions under all postulated environmental conditions, including temperature, for the entire qualified life of the equipment. The qualification process must demonstrate, prior to installation and continually during operation, that systems, structures, and components (SSCs) important to safety will function as required under the most limiting environmental conditions of normal operation, anticipated operational occurrences, and accident scenarios. If plant environmental conditions changesuch as those resulting from a revised operating temperature profilelicensees must reassess and, if necessary, update their qualification documentation and analyses to ensure continued compliance with 10 CFR 50.49. This includes considering cumulative exposure and the effects of aging, not only initial type-testing.
When SSCs important to safety operate in environments and/or for durations not fully covered by their qualification basis, there is an increased risk of unexpected failure mechanisms emergingespecially during accident conditions, where multiple severe stresses (temperature, pressure, radiation, etc.) may act simultaneously. Extended or even intermittent operation above a temperature setpoint threshold without automatic isolation may inadvertently expose SSCs important to safety to conditions exceeding their original qualification, leading to undetected age-related or installation-induced degradation manifesting as failures under stress. Operating above a temperature threshold may also affect determination of environmental qualification zones (i.e., result in adding or expanding an environmental qualification zone due to changes in initial condition assumptions).
REQUEST FOR ADDITIONAL INFORMATION
The NRC staff notes that depending on the timing to complete the post-threshold engineering reviews of qualified Structures, Systems, and Components (SSCs), there is potential for prolonged exposure to elevated temperatures that can significantly degrade materials and components, potentially affecting mechanical strength, electrical insulation, and sealing performance, thereby shortening the qualified life and potentially impacting the functional capability of SSCs requiring qualification.
As stated in the LAR,
Removing the automatic isolation function and adding a reactor shutdown requirement on high MST area temperature will have no adverse effect on equipment qualification. Once the 195ºF temperature threshold is entered, procedural guidance will trigger an engineering review of qualified SSCs to evaluate the actual condition and any remedial actions.
The staff requests the licensee to provide justification as to how the stated determination was reached and explain how environmental qualification zones have been or would be assessed when/if temperatures exceed the 195ºF threshold. Additionally, with respect to the inclusion of procedural guidance requiring post-threshold engineering review of qualified SSCs (i.e., manual actions), provide the supporting rationale for the timely identification and remediation of qualification issues to ensure the continued qualification of equipment, including possible adverse impacts on material integrity, functional performance, and qualified life due to sustained high temperatures.
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From: Richard Guzman Sent: Thursday, September 4, 2025 10:13 AM To: Henry, Michael: (Constellation Nuclear) <Michael.Henry@Constellation.com>
Subject:
RE: [EXTERNAL]FitzPatrick Licensing Activities Meeting with NRC PM
- Mike,
Below is a draft RAI to support a clarification call discussion w/the appropriate folks from your end and the NRR reviewers. We can go over next steps and any questions you may have during our touch point at 4p today.
- Thanks, Rich