ML14262A330

9/16/2014 Meeting Slide for Sequoyah Nuclear Plant, Units 1 and 2 Regarding AST Presentation

ML14262A330
Person / Time
Site:	Sequoyah
Issue date:	09/16/2014
From:	Tennessee Valley Authority
To:	Office of Nuclear Reactor Regulation
Hon A DORL/LPL2-2 301-415-8480
References
Download: ML14262A330 (17)

Text

Sequoyah Nuclear Plant (SQN) Nuclear AST Presentation September 16, 2014

Introduction Purpose of Meeting

• Discussion of AST as it pertains to RAI KAB-044

- Current Licensing Bases

- Improved Technical Specification Impact

Introductions

• NRC

• TVA 2 TVA Nuclear Power Group

Current Licensing Bases

• TVA-SQN-TS-02-08 submitted to NRC, January 14, 2003

- Request to modify TS 3.9.4 Containment Building Penetrations and Partial scope implementation of the alternate source term

- Modified applicability requirement for the containment building equipment door (CBED)

- CBED closure only required during recently irradiated fuel

• NRC approval received on October 28, 2003 3 TVA Nuclear Power Group

Current Licensing Basis Current wording for T/S 3.9.4 4 TVA Nuclear Power Group

Current Licensing Basis

• TVA and NRC recognized that the Fuel Handling Accident (FHA) within containment is the only Design Basis Accident (DBA) affected by the proposed change

• TVA evaluated a FHA both inside and outside containment

• NRC found that the change to replace the current accident source term used in the design basis FHA within containment with an AST was acceptable 5 TVA Nuclear Power Group

Current Licensing Basis Excerpt from NRC SE 6 TVA Nuclear Power Group

Current Licensing Basis Excerpt from NRC SE 7 TVA Nuclear Power Group

Current Licensing Basis

• Analysis done for the FHA with AST assumes that the CBED is open and that ABGTS is out of service (no filtration of releases)

• TVA revised some of the assumptions in the FHA Analysis of Record (AOR) in June of 2013

- Changed the time of the CVI from 30 to 300 seconds

- Changed the containment air volume for mixing from 5% to 50%

- Change was done under 10 CFR 50.59

- Consequences to the FHA decreased by ~7%

8 TVA Nuclear Power Group

Current Licensing Basis

• Analysis done for the FHA with AST assumes that the CBED is open and that ABGTS is out of service (no filtration of releases)

• TVA revised some of the assumptions in the FHA Analysis of Record (AOR) in June of 2013

- Changed the time of the CVI from 30 to 300 seconds

- Changed the containment air volume for mixing from 5% to 50%

- Change was done under 10 CFR 50.59

- Consequences to the FHA decreased by ~7%

9 TVA Nuclear Power Group

Current Licensing Basis 10 TVA Nuclear Power Group

Current Licensing Basis 11 TVA Nuclear Power Group

Current Licensing Basis 12 TVA Nuclear Power Group

Improved Tech Spec Impact

• Four T/S were changed in this conversation by changing the APPLICABILITY from During movement of irradiated fuel to During movement of recently irradiated fuel

- 3.3.6 Containment Ventilation Isolation Instrumentation

- 3.3.8 Auxiliary Building Gas Treatment System Actuation Instrumentation

- 3.7.12 Auxiliary Building Gas Treatment System

- 3.9.4 Containment Penetrations

• In none of these specifications, does SQN CTS have DURING CORE ALTERATIONS 13 TVA Nuclear Power Group

Improved Tech Spec Impact

• 3.3.6 Containment Ventilation Isolation Instrumentation 14 TVA Nuclear Power Group

Improved Tech Spec Impact

• 3.3.8 Auxiliary Building Gas Treatment System Actuation Instrumentation 15 TVA Nuclear Power Group

Improved Tech Spec Impact

• 3.7.12 Auxiliary Building Gas Treatment System 16 TVA Nuclear Power Group

Improved Tech Spec Impact

• 3.9.4 Containment Penetrations 17 TVA Nuclear Power Group