ML24283A202

Slides - SNC Presentation - Pre-Submittal Meeting on October 16, 2024 - Proposed Vogtle 3 and 4 Flexibility Modes LAR

ML24283A202
Person / Time
Site:	Vogtle
Issue date:	10/09/2024
From:	Southern Nuclear Operating Co
To:	John Lamb Southern Nuclear Operating Co
Shared Package
ML24283A204	List: ML24283A202
References
EPID L-2024-LRM-0117
Download: ML24283A202 (14)

Text

Proposed Vogtle Electric Generating Plant Units 3 & 4 License Amendment Request Revise Technical Specifications to Increase Flexibility in Mode Restraints Pre-submittal Meeting: October 2024

Agenda Background Information Current Requirements Proposed Changes Technical Evaluation Regulatory Evaluation Discussion / Feedback

Revise Technical Specifications to Increase Flexibility in Mode Restraints BACKGROUND INFORMATION Consistent with the Commission's policy statement on TS and the use of PRA, the NRC and industry developed risk-informed initiatives and associated travelers for improvements to the Standard TS (STS).

Initiative 1 - TS Required Actions Preferred End States Initiative 2 - Missed Surveillances SR 3.0.3 Initiative 3 - Increased Flexibility in Mode Restraints LCO 3.0.4 Initiative 4b - Risk-Informed Completion Times Initiative 5b - Relocate Surveillance Test Intervals to Licensee Control Initiative 7a - Impact of non-TS Design Features on Operability (Barriers/Snubbers) 3

Revise Technical Specifications to Increase Flexibility in Mode Restraints BACKGROUND INFORMATION In April 2003, the availability of TSTF-359, Rev. 9 (TSTF-359) was announced in the Federal Register as part of the CLIIP (68 FR 16579).

TSTF-359 is a traveler that made changes to the STS and revised LCO 3.0.4 to allow entry into a MODE or other specified condition in the Applicability, while relying on the associated ACTIONS, if the provisions of LCO 3.0.4 were met (ML031190607).

TSTF-359 has been adopted by many licensees across the industry including SNCs other units - Farley, Hatch, and VEGP 1&2.

In February 2019, TSTF-529, Rev. 4 (TSTF-529) was transmitted and proposed changes to clarify and expand the use and application of the STS usage rules, which included minor enhancements to LCO 3.0.4 (ML16062A271 / ML16060A440).

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Revise Technical Specifications to Increase Flexibility in Mode Restraints CURRENT REQUIREMENTS Limiting Condition for Operation (LCO) 3.0.4

- LCO 3.0.4 precludes placing the unit in a MODE or other specified condition in the Applicability except when the associated ACTIONS permit continued operation, for an unlimited period of time

- TS 3.3.17, TS 3.3.18, TS 3.4.9, and TS 3.4.10 include exceptions - LCO 3.0.4 is not applicable

- Only applicable for entry into MODES 1 - 4 Surveillance Requirement (SR) 3.0.4

- Requires that all applicable SRs be met before entry into a MODE or other specified condition in the Applicability

- Only applicable for entry into MODES 1 - 4 5

6 Proposed Changes to LCO 3.0.4

7 Proposed Changes to SR 3.0.4

Revise Technical Specifications to Increase Flexibility in Mode Restraints ADDITIONAL CHANGES The current LCO 3.0.4 exceptions in TSs 3.3.17, 3.3.18, and 3.4.9 are removed.

The current LCO 3.0.4 exception in TS 3.4.10 (RCS Activity) will be revised from LCO 3.0.4 is not applicable to LCO 3.0.4.c is applicable.

A Note is added to TS 3.4.14, Low Temperature Overpressure Protection (LTOP), to prohibit the application of LCO 3.0.4.b to an inoperable LTOP system.

The TS Bases are revised to explain the new LCO 3.0.4 allowance and reflect other changes. The mark-ups are provided in the LAR for information only.

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Revise Technical Specifications to Increase Flexibility in Mode Restraints TECHNICAL EVALUATION

• The VEGP 3&4 LAR uses similar arguments as those in the Justification Section of TSTF-359.

• The current LCO 3.0.4 allowance is retained as LCO 3.0.4.a without the need for risk assessment as the ACTIONS allow indefinite operation.

• The Configuration Risk Management Program (CRMP) and Shutdown Defense-In-Depth (DID) model will be used to evaluate the configuration-specific risk, when changing modes per LCO 3.0.4.b.

• The current LCO 3.0.4 exceptions (TS 3.3.17, 3.3.18, 3.4.9) are deleted as a mode change could be made in accordance with the provisions of the proposed LCO 3.0.4 (e.g., risk assessment per LCO 3.0.4.b).

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Revise Technical Specifications to Increase Flexibility in Mode Restraints TECHNICAL EVALUATION

• Use of LCO 3.0.4.b will be prohibited when the LTOP system is inoperable (LCO 3.4.14 not met). The LCO requires at least one overpressure protection methods.

• A review is being conducted to determine if LCO 3.0.4.b should be prohibited for additional systems. These exceptions are expected to be limited given the passive design features of the AP-1000 (e.g., EDGs not credited in TS).

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Revise Technical Specifications to Increase Flexibility in Mode Restraints REGULATORY EVALUATION 10 CFR 50.36:

TS are required to include items in the following five specific categories related to station operation:

(1) safety limits, limiting safety system settings, and limiting control settings; (2) limiting conditions for operation (LCOs);

(3) surveillance requirements (SRs);

(4) design features; and (5) administrative controls.

The proposed changes provide additional flexibility by allowing use of a risk assessment to determine the acceptability of entering a MODE or other specified condition in the Applicability, and through the establishment of risk management actions, if appropriate. The proposed changes are consistent with the requirements of 10 CFR 50.36.

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Revise Technical Specifications to Increase Flexibility in Mode Restraints PRECEDENT TSTF-359 was announced in the Federal Register on April 4, 2003 (68 FR 16579) as part of the CLIIP.

Millstone submitted a LAR on April 6, 2022 (ML22096A221) to revise the TS requirements for mode change limitations to adopt the provisions of TSTF-359 (Amendment/SE is ML23058A454). The proposed changes to the VEGP 3&4 TS are similar to those in the Millstone LAR.

The VEGP 3&4 LAR is being processed as a normal license amendment since TSTF-359 does not directly address the AP1000 design (e.g., does not include TS markups for AP1000).

Farley, Hatch, VEGP 1&2 Amendments to adopt TSTF-529 - ML17137A041.

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Revise Technical Specifications to Increase Flexibility in Mode Restraints Remaining Actions and Schedule

• Submit LAR to NRC December 2024 13

Revise Technical Specifications to Increase Flexibility in Mode Restraints

• Discussion and Questions 14