ML21119A228

NRR E-mail Capture - Request for Additional Information (RAI) - LaSalle, EPID-L-2020-LLA-0018, License Amendment Request (LAR) TSTF-505

ML21119A228
Person / Time
Site:	LaSalle
Issue date:	04/29/2021
From:	Bhalchandra Vaidya NRC/NRR/DORL/LPL3
To:	Kusumawatimurray P, Taken J Exelon Generation Co
References
L-2020-LLA-0018
Download: ML21119A228 (3)

Text

From: Vaidya, Bhalchandra Sent: Thursday, April 29, 2021 9:50 AM To: Taken, Jason C.:(Exelon Nuclear); Kusumawatimurray, Putri:(Exelon Nuclear)

Subject:

REQUEST FOR ADDITIONAL INFORMATION (RAI) - LaSalle, EPID-L-2020-LLA-0018, License Amendment Request (LAR) re: TSTF-505

SUBJECT:

REQUEST FOR ADDITIONAL INFORMATION (RAI) - LaSalle, EPID-L-2020-LLA-0018, License Amendment Request (LAR) re: TSTF-505 Dwi and Jason, During its review of the LAR and licensee supplemental letters, the U.S. Nuclear Regulatory Commission (NRC) staff reviewed LAR Enclosure 1, Table E1-1, In Scope TS/LCO Conditions to Corresponding PRA Functions, which will be used for safety-evaluation conclusions. The staff believes that the present information regarding the Design Success Criteria (DSC) submitted on the docket in Table E1-1, is inconsistent against other information in the LAR and Supplements. Therefore, the NRC staff needs additional information that provides the explanation regarding the differences. The Request for Additional Information (RAI) is provided below:

===========================

LICENSE AMENDMENT REQUEST TO ADOPT TSTF-505, REVISION 2 RISK-INFORMED COMPLETION TIMES EXELON GENERATION COMPANY, LLC LASALLE COUNTY STATION UNITS 1 AND 2 REQUEST FOR ADDITIONAL INFORMATION (RAI)

By letter dated January 31, 2020, (Agencywide Documents Access and Management System (ADAMS)

Accession No. ML20035E577) Exelon Generation Company LLC (Exelon, the licensee) submitted a license amendment request (LAR) to modify the LaSalle County Station (LaSalle) TS requirements to permit the use of Risk Informed Completion Times (RICT) in accordance with Technical Specifications Task Force (TSTF) Traveler TSTF-505, Revision 2, Provide Risk-Informed Extended Completion Times

- RITSTF Initiative 4b, dated July 2, 2018 (ADAMS Accession No. ML18183A493). The U.S. Nuclear Regulatory Commission (NRC) staff has reviewed the request and supplemental information provided in letters dated October 1, 2020, LaSalle County Station Unit 1 And 2 - Response to Request for Additional Information for LaSalle License Amendment Request to Adopt Risk-Informed Completion Times TSTF-505, Revision 2 (ADAMS Accession No. ML20275A270) and March 31, 2021, LaSalle County Station Unit 1 And 2 - Response to Second Round Request for Additional Information (RAIs) for LaSalle License Amendment Request to Adopt Risk-Informed Completion Times TSTF-505, Revision 2 (ADAMS Accession No. ML21090A283).

EEOB ROUND 3 RAI:

During its review of the LAR and supplemental letters, the staff noted that the information regarding the Design Success Criteria (DSC) in LAR Enclosure 1, Table E1-1, In Scope TS/LCO Conditions to Corresponding PRA Functions, is inconsistent with other information in the LAR and Supplements.

Specifically, the DSC for TS 3.8.1, Condition B (and referred to for Condition C), states that one diesel per division for a unit is necessary for performance of the requisite safety functions. Three diesel generators (DGs) for Divisions 1, 2, and 3 must be available to meet that DSC for a unit experiencing a design basis accident. If any DG for that unit is unavailable for that scenario, for example Division 1 DG, that DSC is not met, and it would be reasonable to conclude that the unit could not safely shutdown. As such, provide additional information that provides the explanation regarding the differences either to confirm the DSC information in Table E1-1 related to the minimum equipment necessary to carry out the safety functions referred to below or provide corrected information.

In LAR Enclosure 1 in Table E1-1, for TS 3.8.1 Condition B under heading Design Success Criteria states, one diesel per division and under heading PRA Success Criteria states Same as Design Success Criteria.

In LAR Enclosure 1 in Table E1-1 for TS 3.8.1 Condition C for disposition for all table headings states See 3.8.1.A and 3.8.1.B.

=========================

During the clarification telephone conference on April 29, 2021, you have committed to provide the responses to these RAIs no later than 30 days from the date of this transmittal.

Please contact me, if you have any questions.

Thanks.

Bhalchandra K. Vaidya US Nuclear Regulatory Commission Office of Nuclear Reactor Regulation Division of Operating Reactor Licensing LPL3 301-415-3308 Bhalchandra.vaidya@nrc.gov

Hearing Identifier: NRR_DRMA Email Number: 1158 Mail Envelope Properties (SJ0PR09MB64150158DD138F79D35529C48D5F9)

Subject:

REQUEST FOR ADDITIONAL INFORMATION (RAI) - LaSalle, EPID-L-2020-LLA-0018, License Amendment Request (LAR) re: TSTF-505 Sent Date: 4/29/2021 9:49:59 AM Received Date: 4/29/2021 9:49:59 AM From: Vaidya, Bhalchandra Created By: Bhalchandra.Vaidya@nrc.gov Recipients:

"Taken, Jason C.:(Exelon Nuclear)" <Jason.Taken@exeloncorp.com>

Tracking Status: None "Kusumawatimurray, Putri:(Exelon Nuclear)" <Putri.Kusumawatimurray@exeloncorp.com>

Tracking Status: None Post Office: SJ0PR09MB6415.namprd09.prod.outlook.com Files Size Date & Time MESSAGE 4354 4/29/2021 9:49:59 AM Options Priority: Normal Return Notification: No Reply Requested: No Sensitivity: Normal Expiration Date: