ML25281A002
| ML25281A002 | |
| Person / Time | |
|---|---|
| Site: | Limerick  |
| Issue date: | 11/20/2025 |
| From: | Marshall M Plant Licensing Branch 1 |
| To: | Constellation Energy Generation |
| Marshall, M | |
| References | |
| EPID L-2022-LRM-0140 | |
| Download: ML25281A002 (0) | |
Text
November 20, 2025 LICENSEE:
Constellation Energy Generation, LLC FACILITY:
Limerick Generating Station, Units 1 and 2
SUBJECT:
SUMMARY
OF MARCH 27, 2025, AND JUNE 25, 2025, CLOSED MEETINGS WITH CONSTELLATION ENERGY GENERATION, LLC ON THE LIMERICK DIGITAL INSTRUMENTATION AND CONTROLS LICENSE AMENDMENT REQUEST (EPID L-2022-LRM-0140)
On March 27, 2025, and June 25, 2025, the U.S. Nuclear Regulatory Commission (NRC) staff held a closed meeting with Constellation Energy Generation, LLC (the licensee, Constellation) at NRC Headquarters in Rockville, Maryland. The purpose of the meeting was to discuss the licensees draft responses to NRC staffs request for additional information (RAIs) concerning the component interface module (CIM) included in the plant protection system that Constellation plans to install in Limerick Generating Station, Units 1 and 2. The meeting notices and agendas, dated March 6, 2025, and May 19, 2025, are available in the NRCs Agencywide Documents Access and Management System (ADAMS) at Accession Nos. ML25085A314 and ML25139A586, respectively. The enclosure to this summary contains a list of attendees.
Meeting participants discussed proprietary information and, therefore, the meeting was not open to the public.
The RAIs and draft responses discussed during the meetings concerned Constellations technical basis for its assertion that the CIM, a priority module, is not susceptible to common cause failure due to latent design defects. During each meeting, the NRC staff provided written (ML25279A009 (non-public) and ML25279A005 (non-public)) and verbal feedback on the licensees draft or updated draft responses to the RAIs that were issued to Constellation by email dated January 6, 2025 (ML25007A150). The NRC staff focused on the draft responses that were insufficient and explained to the licensee why those draft responses were insufficient.
Constellation asked questions to help it better understand what additional information would be needed to make its draft responses sufficient. Additionally, the NRC staff described how other licensees and applicants have successfully demonstrated in applications approved by the NRC that priority modules are not susceptible to common cause failure due to latent design defects.
During the June 25, 2025, meeting, the NRC staff asked the licensee if it was considering other options for addressing the consideration of common cause failure due to latent design defects and described other options available to Constellation to complete the review of the Limerick digital instrumentation and controls license amendment request prior to its planned installation in 2026. The licensee expressed a preference to continue iterating on its technical basis for its assertion that the CIM is not susceptible to common cause failure due to latent design defects, but a willingness to consider other options to complete the review. In a presentation (ML25279A014 (non-public)), the licensee provided additional information intended to support its assertion. After the meeting, the NRC staff provided the licensee with a list of options for its consideration (ML25280A043) and feedback on its presentation (ML25280A047 (non-public)).
The NRC staff did not make any regulatory decisions at the meetings. Members of the public were not in attendance. Public Meeting Feedback forms were not received.
Please direct any inquiries to me at (301) 415-2871, or Michael.Marshall@nrc.gov.
/RA/
Michael L. Marshall, Jr., Senior Project Manager Plant Licensing Branch I Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-352 and 50-353
Enclosure:
List of Attendees cc: Listserv
Enclosure LIST OF ATTENDEES MARCH 27, 2025, MEETING WITH CONSTELLATION LIMERICK, UNITS 1 AND 2 U.S. Nuclear Regulatory Commission Constellation Aida Rivera Ashley Rickey Gilberto Blas (remote attendance)
Brian Devine (remote attendance)
Jack Zhao (remote attendance)
David Gullot Jonathan Evans David Peiffer (remote attendance)
Malcolm Patterson Kayla Marriner (remote attendance)
Meena Khanna (remote attendance)
Jerry Segner (remote attendance)
Ming Li (remote attendance)
Mark Samselski Shilp Vasavada (remote attendance)
Michael Foote (remote attendance)
Steve Alferink (remote attendance)
Michael Gillin (remote attendance)
Tania Martinez Navedo Ron DiSabatino William Roggenbrodt Sailaja Mokkapati Youssef Rokes (remote attendance)
Steve Hesse Wendi Para Zina Gavin (remote attendance)
Westinghouse Arati Chandrasekhara (remote attendance)
Chris Crefeld Sargent & Lundy Courtney Frank (remote attendance)
Pareez Golub Jerrod Ewing (remote attendance)
Johnathan Semanco (remote attendance)
Matthew Shakun Members of the Public Murat Uzman (remote attendance) n/a Nader Mamish Parastoo Muse (remote attendance)
Steve Seaman Thomas Tweedle (remote attendance)
Uyar, Hasan (remote attendance)
Warren Odess-Gillett (remote attendance)
LIST OF ATTENDEES JUNE 25, 2025, MEETING WITH CONSTELLATION LIMERICK, UNITS 1 AND 2 U.S. Nuclear Regulatory Commission Constellation Adam Ziedonis (remote attendance)
Ashley Rickey (remote attendance)
Aida Rivera Brian Devine (remote attendance)
Christina Antonescu (remote attendance)
Jerry Segner (remote attendance)
David Rahn (remote attendance)
Madison Long (remote attendance)
Fanta Sacko Mark Samselski Jonathan Evans Michael Foote (remote attendance)
Malcolm Patterson Michael Gillin (remote attendance)
Mike Franovich Sailaja Mokkapati Ming Li Steve Hesse Robert Kuntz (remote attendance)
Wendi Para Samir Darbali (remote attendance)
William Levis (remote attendance)
Steve Alferink (remote attendance)
Tania Martinez Navedo William Roggenbrodt Sargent & Lundy Westinghouse Pareez Golub (remote attendance)
Arati Chandrasekhara Chris Crefeld Courtney Frank (remote attendance)
Members of the Public Hasan Uyar (remote attendance) n/a Jerrod Ewing Matthew Shakun (remote attendance)
Parastoo Muse (remote attendance)
Steve Seaman Thomas Tweedle (remote attendance)
Warren Odess-Gillett
ML25281A002 NRC-001 OFFICE NRR/DORL/LPL1/PM NRR/DORL/LPL1/LA NRR/DORL/LPL1/BC (A) NRR/DORL/LPL1/PM NAME MMarshall KEntz UShoop MMarshall DATE 10/08/2025 11/13/2025 11/19/2025 11/20/2025