ML24190A108

NRC Slides-07/11/2024 Mtg to Exchange Technical Information Regarding Joseph M. Farley Nuclear Plant, Units 1 & 2, Proposed License Amendment Request to Increase TS 3.6.5 Containment Temperature Limit Completion Using Risk-Informed Process

ML24190A108
Person / Time
Site:	Farley
Issue date:	07/08/2024
From:	Turner Z Plant Licensing Branch II
To:	Southern Nuclear Operating Co
Turner, Zachary
References
TS 3.6.5
Download: ML24190A108 (1)

Text

1 Discuss SNCs previous License Amendment Request to Revise Joseph M.

Farley Nuclear Plant, Units 1 and 2, Actions and Completion Times in TS 3.6.5, Containment Air Temperature, using RIPE Date: July 11, 2024 1

Observation Public Meeting

2 Purpose

• Provide a brief background related to SNC's LAR to modify Joseph M. Farley Nuclear Plant, Units 1 and 2, TS 3.6.5, "Containment Air Temperature" under RIPE

• Ensure a common understanding of SNC's previous LAR dated April 19, 2024, as supplemented

• Identify informational needs for any future LARs related to modifying TS 3.6.5 for RIPE and/or traditional reviews 2

3 Key messages

• SNC's April 2024 Farley submittal (under RIPE) was a request for a permanent change similar to an emergent, time-limited LAR which was granted for 16 days to preclude a plant shutdown. Permanent changes require a more complete justification and review than one-time, time-limited requests.

• NRC understands the likely seasonal need for a containment temperature licensing modification. NRC is committed to an expedited review whether resubmitted as a RIPE or non-RIPE licensing request.

4 Background - August 2023 Emergency Amendment

• Emergency Amendment - August 24, 2023 (ML23235A296)

-Amendment expired on September 9, 2024 (16 days) 4

5 Background - RIPE LAR Pre-submittal meeting

• Pre-submittal meeting was held on April 3, 2024

-SNC slides (ML24088A166)

-Meeting summary - April 12, 2023 (ML24096A183) 5

6 Background-SNCs RIPE LAR Submittal

-SNC submittal April 19, 2024 (ML24110A126)

-NRC Request for Supplemental Information May 28, 2024 (ML24143A041)

-SNC Supplement June 14, 2024 (ML24166A290)

-NRC Nonacceptance Letter July 1, 2024 (ML24178A376) 6

7 Farley RIPE LAR

• SNC submitted Farley RIPE LAR on April 19, 2024 (ML24110A126)

• TS 3.6.5 Actions, upon exceeding the containment average air temperature limit, are proposed to be revised to allow continued operation for up to 30 cumulative days provided:

the containment average air temperature remains less than or equal to 122oF (verified within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> and once per 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> thereafter);

the containment average air temperature has not exceeded the 120oF limit for more than 720 cumulative hours during the current calendar year (verified within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> and once per 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> thereafter); and the refueling water storage tank temperature remains less than or equal to 100oF (verified within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> and once per 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />

8

9 Technical Discussion In the original application, as supplemented, there were areas where additional information would be needed or expanded on to accept the licensees submittal:

• PCT

- NRC staff seeks to understand the methodology SNC used to determine increase in PCT as an effect of increased Containment Average Air Temperature

• NPSH

- NRC staff seeks to clarify the version and inputs/assumptions of SNC's GOTHIC model on LOCA sump temperature response

• TS

- NRC staff seeks to understand how the proposed change in TS 3.6.5 is derived from analysis and evaluation included in the Safety Analysis Report 9

10 Technical Discussion - PCT

• Plant-specific Methodology - The application did not provide sufficient information to assess the analytical methods and results concerning the plant-specific effects of increasing PCT would have on a large break LOCA, explicit to Joseph M. Farley Nuclear Plant, Units 1 and 2.

• 10 CFR 50 App B Design Control - The application did not discuss how the remaining PCT margin would be tracked or documented for future reviews.

- 10 CFR 50.46(b)(1) requires PCT not exceed 2200°F 10

11 Technical Discussion - NPSH

• GOTHIC Code - The application did not describe the version of the GOTHIC code used. More information is needed on uncertainties and on inputs that impact LOCA sump temperature response.

• NPSH Margin - The application did not describe the NPSH margin for containment spray pumps during the LOCA recirculation phase.

11

12 Technical Discussion - TS

• Should the application be resubmitted, technical issues may drive the structure of an appropriate TS for the change IAW 10 CFR 50.36.

• Remedial Action vs LCO-The application did not provide a justification for why the proposed change would not be considered an LCO rather than a remedial action.

- 10 CFR 50.36(c)(2) defines LCO as the lowest functional capability or performance levels of equipment required for safe operation of the facility.

12

13 Path Forward

• The NRC staff is committed to an expeditious review of this LAR, if resubmitted, whether under RIPE or non-RIPE.

• The NRC would expect this submittal to inform future reviews and the RIPE process.

14 Acronyms CFR - Code of Federal Regulations LAR - License Amendment Request LCO - Limiting Conditions for Operation LOCA - Loss of Coolant Accident NPSH - Net Positive Suction Head PCT - Peak Cladding Temperature RIPE - Risk-Informed Process for Evaluation SNC - Southern Nuclear Company TS - Technical Specification 14

15 Questions?