ML23089A160

NRR E-mail Capture - NRC Notification to the Commonwealth of Pennsylvania Re. Limerick Generating Station, Units 1 and 2 Amendment - Alternative 10 CFR 50.69 Categorization Approaches

ML23089A160
Person / Time
Site:	Limerick
Issue date:	03/30/2023
From:	Audrey Klett NRC/NRR/DORL/LPL1
To:	Lafleur D State of PA, Dept of Environmental Protection
Klett A
References
L-2021-LLA-0042
Download: ML23089A160 (7)

Text

From: Audrey Klett Sent: Thursday, March 30, 2023 8:55 AM To: dlafleur@pa.gov Cc: sandmartin@pa.gov

Subject:

NRC Notification to the Commonwealth of Pennsylvania Re. Limerick Generating Station, Units 1 and 2 Amendment - Alternative 10 CFR 50.69 Categorization Approaches Attachments: ML23076A280.pdf

Good morning, Mr. Lafleur,

Per our discussion this morning, Im sending this email as a follow-up.

The U.S. Nuclear Regulatory Commission (NRC) is preparing to issue a license amendment for the Limerick Generating Station, Units 1 and 2. In accordance with Title 10 of the Code of Federal Regulations, Section 50.91(b), I am notifying you of the proposed issuance of this amendment.

Please reply if the Commonwealth of Pennsylvania has comments on the following requested licensing action submitted to the NRC by Exelon Generation Company, LLC (now Constellation Energy Generation, LLC, the licensee), Application to Implement an Alternate Defense-in-Depth Categorization Process, an Alternate Pressure Boundary Categ orization Process, and an Alternate Seismic Tier 1 Categorization Process in Accordance with the Requirements of 10 CFR 50.69, Risk-Informed Categorization and Treatment of Structures, Systems and Components for Nuclear Power Reactors, by letter dated March 11, 2021 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML21070A412), as supplemented by letters dated May 5, 2021 (ML21125A215), December 15, 2021 (ML21349B364), February 14, 2022 (ML22045A480), and June 30, 2022 (ML22182A40 0).

The proposed amendment would modify the 10 CFR 50.69 license condition to allow for an alternative seismic approach for categorizing structures, systems, and components under 10 CFR 50.69. However, the NRC plans to deny the licensees request to use a lternative defense-in-depth and pressure boundary categorization approaches, as discussed during the public meeting held on February 23, 2023 (ML23076A283, also attached since it may not be available to the public yet).

The proposed no significant hazards consideration for this amendment request was published in the Federal Register on March 18, 2022 (87 FR 15458).

Please respond with comments, if any, by April 28, 2023.

Thank you,

Audrey Klett, Senior Project Manager U.S. Nuclear Regulatory Commission Office of Nuclear Reactor Regulation Division of Operating Reactor Licensing Plant Licensing Branch 1 301-415-0489

Hearing Identifier: NRR_DRMA Email Number: 2023

Mail Envelope Properties (SJ0PR09MB9336DEA8D1EDF72FDE1E32B3878E9)

Subject:

NRC Notification to the Commonwealth of Pennsylvania Re. Limerick Generating Station, Units 1 and 2 Amendment - Alternative 10 CFR 50.69 Categorization Approaches Sent Date: 3/30/2023 8:54:39 AM Received Date: 3/30/2023 8:54:00 AM From: Audrey Klett

Created By: Audrey.Klett@nrc.gov

Recipients:

"sandmartin@pa.gov" <sandmartin@pa.gov>

Tracking Status: None "dlafleur@pa.gov" <dlafleur@pa.gov>

Tracking Status: None

Post Office: SJ0PR09MB9336.namprd09.prod.outlook.com

Files Size Date & Time MESSAGE 2194 3/30/2023 8:54:00 AM ML23076A280.pdf 286209

Options Priority: Normal Return Notification: No Reply Requested: No Sensitivity: Normal Expiration Date:

March 28, 2023

Mr. David P. Rhoades Senior Vice President Constellation Energy Generation, LLC President and Chief Nuclear Officer Constellation Nuclear 4300 Winfield Road Warrenville, IL 60555

SUBJECT:

LIMERICK GENERATING STATION, UNITS 1 AND 2 -

SUMMARY

OF FEBRUARY 23, 2023, PUBLIC OBSERVATION MEETING WITH CONSTELLATION ENERGY GENERATION, LLC RE. PROPOSED LICENSE AMENDMENT REQUEST TO MO DIFY TITLE 10 OF THE CODE OF FEDERAL REGULATIONS, SECTION 50.69 LICENSE CONDITIONS (EPID L-2021-LLA-0042)

Dear Mr. Rhoades:

On February 23, 2023, the U.S. Nuclear Regulatory Commission (NRC) staff held a hybrid in-person and virtual public meeting 1 with representatives from Constellation Energy Generation, LLC (Constellation or the licensee), the Pressurized Water Reactor Owners Group (PWROG), and the Electric Power Research Institute (EPRI). 2 The purpose of the meeting was to discuss the NRC staffs preliminary partial denial of Constellation s license amendment request 3 for Limerick Generating Station, Units 1 and 2 (Limerick). Constellation requested NRC to modify the existing Limerick lic ense conditions for Title 10 of the Code of Federal Regulations, Section 50.69 (10 CFR 50.69), Risk-informed categorization and treatment of structures, systems and components for nuclear pow er reactors, to allow Constellation to use alternative defense-in-depth (DID), pressure boundary, and seismic categorization processes for treatment of systems, structures, and components (SSCs) per 10 CFR 50.69.

The enclosure to this summary contains a list of attendees. NRC staffs presentation slides are available in Agencywide Documents Access and Management System (ADAMS) under Accession No. ML23053A156. The licensees presentations on the pressure boundary and DID processes are available at ADAMS Accession Nos. ML23076A281 and ML23076A282, respectively.

1 The meeting notice and agenda, dated February 9, 2023, are available in ML23053A199.

2 This meeting summary refers to representatives from the licensee, EPRI, the PWROG, and other licensee contractors as the licensee.

3 ML21070A412 dated March 11, 2021, as supplemented (ML21125A215 dated May 5, 2021, ML21349B364 dated December 15, 2021, ML22045A480 dated February 14, 2022, and ML22182A400 dated June 30, 2022)

D. Rhoades 2

During the first portion of the meeting, the NRC st aff discussed its basis for its preliminary denial of the proposed pressure boundary categorization process. The staff discussed its preliminary conclusions that the proposed pressure boundary categorization process appears to lack technical justification for the list of high safety-significant (HSS) SSCs and appears to have inconsistent risk criteria. The licensee then gave a presentation, which is available at ADAMS Accession No. ML23076A281, in response to the st affs concerns. The licensee indicated that the existing approved methodology, guidance, and requirements are also complicated and have conservatisms built into them. The licensee presented its view that the risk-informed methodology in its proposal is technically robust and positive for stakeholders.

During the second portion of the meeting, the NRC staff discussed its basis for its preliminary denial of the proposed DID categorization process, including that the proposed process appears to: (1) have inconsistent and lack of correlation to layers of defense; (2) inappropriately default to using the integrated decision-making panel and engineering teams to compensate for the reduced rigor in the proposed DID categorization process; (3) have insufficient basis for treatment of common cause failures; and (4) have unjustified mixed use of DID processes. The licensee then gave the presentation, which is available at ADAMS Accession No. ML23076A282, in response to the staffs concerns. The licensee presented its view that the proposed process provides for a realistic interpreta tion of DID in the evaluation of risk scenarios at the plant and has considerations for a confirmation check on the process, including engineering team reviews. The licensee presented its view that it is realistic to have a prescriptive detailed categorization process that is repeatable for evaluating core damage DID.

The licensee stated that credit can be taken for redundancy in core damage DID (other evaluations may classify the components as candidate HSS) if a common cause event of four or more components leads to core damage. The licensee noted that the NRC has allowed mixed use of processes for seismic risk consideration in 10 CFR 50.69 categorization processes.

The NRC staff did not make any regulatory decisions at the meeting. The NRC staff informed the licensee that it would consider the information presented at the meeting and contact the licensee later to discuss the staffs plans regarding the application.

The enclosure to this summary lists members from the public that attended the meeting. Two members of the public had questions or comments about the meeting. One member of the public asked about probabilistic risk assessment experience at the NRC. The other member of the public discussed observations and benefits obtained from piloting the proposed process at Duke Energy sites. The NRC staff did not receive any public meeting feedback forms.

D. Rhoades 3

Please direct any inquiries to me at 301-415-0489 or by email to Audrey.Klett@nrc.gov.

Sincerely,

/RA/

Audrey L. Klett, 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 LIST OF ATTENDEES AT FEBRUARY 23, 2023, PUBLIC MEETING LIMERICK GENERATING STATION, UNITS 1 AND 2

U.S. Nuclear Regulatory Commission Constellation Energy Generation, LLC Bo Pham Darani Reddick Mike Franovich Stephen Flickinger Meena Khanna Roy R. Linthicum Mihaela Biro Suzanne Loyd Jeff Circle Jeffrey Stone Stephen Cumblidge Thomas Basso Daniel Widrevitz George Budock Audrey Klett Dana DeAngelis Observers Philip Tarpinian Jr.

Bernie Thomson Jeremy Thoryk Brian Smith Bob Pascarelli Jensen Hughes Shilp Vasavada Brian Nolan Sunil Weerakkody David Passehl Ed Miller Charles Young Adriene Brown David Bidwell Alexander Schwab Ali Rezai Westinghouse Alissa Neuhausen Richard W. Rolland, III Anne-Marie Grady Bradley Dolan April Pulvirenti Damian Mirizio Bart Fu Dewey Olinski Carol Moyer Heather Detar Carolyn Fairbanks Thomas Laubham Ching Ng Jim Andrachek Cory Parker Dan Widrevitz Electric Power Research Institute De Wu Douglas Kull Eric Reichelt Patrick ORegan Jay Collins James Chapman Jeff Circle Fernando Ferrante Jigar Patel John Honcharik Members of the Public John Wise Bob Post, Enercon Keith Tetter Greg Norris, Entergy Malcolm Patterson Rob Burg, EPM Elena Herrera Torres Aram Kayserian, EPM Matthew Humberstone Bradley Tyers, BWROG Matthew Mitchell Edwin Lyman, Union of Concerned Scientists Omar Khan Jennifer Varnedoe, Duke Energy Richard Guzman Mary Miller, Dominion Contractor Robert Davis Bob Kalinowski Shilp Vasavada Stacey A. C.

Stacey Rosenberg Clayton Crouch Steven Alferink Elliott Korb Sunwoo Park Melinda Higby Todd Hilsmeier Vicken Khatchadourian Varoujan Kalikian Raymond Thomas

Enclosure

Package: ML23076A283 Summary &

Enclosure:

ML23076A280 NRC Presentation Slides: ML23053A156 Licensee Presentation on Pressure Boundary Process: ML23076A281 Licensee Presentation on Defense-in-Depth Process: ML23076A282 OFFICE NRR/DORL/LPL1/PM NRR/DORL/LPL1/LA NRR/DRA/APLA/BC NAME AKlett KZeleznock (KEntz for) RPascarelli DATE 03/17/2023 03/20/2023 03/24/2023 OFFICE NRR/DNRL/NVIB/BC NRR/DNRL/NPHP/BC NRR/DORL/LPL1/BC NAME ABuford MMitchell HGonzález DATE 03/24/2023 03/20/2023 03/28/2023 OFFICE DORL/LPL1/PM NAME AKlett DATE 03/28/2023