CNL-16-049, Withdrawal of Application to Modify Ice Condenser Technical Specifications to Address Revisions in Westinghouse Mass and Energy Release Calculation (SQN-TS-12-04)

Withdrawal of Application to Modify Ice Condenser Technical Specifications to Address Revisions in Westinghouse Mass and Energy Release Calculation (SQN-TS-12-04)

ML16264A456
Person / Time
Site:	Sequoyah
Issue date:	09/19/2016
From:	James Shea Tennessee Valley Authority
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
CNL-16-049, SQN-TS-12-04, TAC MF2446, TAC MF2447
Download: ML16264A456 (4)

Text

Tennessee Valley Authority, 1101 Market Street, Chattanooga, Tennessee 37402 CNL-16-049 September 19, 2016 10 CFR 50.4 ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, D.C. 20555-0001 Sequoyah Nuclear Plant, Units 1 and 2 Renewed Facility Operating License Nos. DPR-77 and DPR-79 NRC Docket Nos. 50-327 and 50-328

Subject:

Sequoyah Nuclear Plant, Units 1 and 2 - Withdrawal of Application to Modify Ice Condenser Technical Specifications to Address Revisions in Westinghouse Mass and Energy Release Calculation (SQN-TS-12-04)

References:

1. Letter from TVA to NRC, Sequoyah Nuclear Plant, Units 1 And 2 -

Application to Modify Ice Condenser Technical Specifications to Address Revisions in Westinghouse Mass and Energy Release Calculation (SQN-TS-12-04), dated July 3, 2013 (ML13199A281)

2. Letter from TVA to NRC, CNL-15-020 Supplement to the Application to Modify Ice Condenser Technical Specifications to Address Revisions in Westinghouse Mass and Energy Release Calculation (SQN-TS-12-04) and Response to NRC Requests for Additional Information, dated April 10, 2015 (ML15117A566)

3. Electronic Mail from NRC to TVA, Sequoyah Nuclear Plant, Units 1 and 2, Related to License Amendment Request to Revise Technical Specification on Ice Condenser Ice Mass (TAC Nos. MF2446 and MF2447), dated July 13, 2015

4. Final Safety Evaluation for Westinghouse Electric Company (Westinghouse)

Topical Report (TR) WCAP-17721-P, Revision 0, And WCAP-17721-NP, Revision 0, Westinghouse Containment Analysis Methodology - PWR

[Pressurized Water Reactor] LOCA [Loss-Of-Coolant Accident] Mass And Energy Release Calculation Methodology, dated August 24, 2015 (ML15221A005)

By letter dated July 3, 2013 (Reference 1), Tennessee Valley Authority (TVA) submitted license amendment request (LAR) SQN-TS-12-04 for Sequoyah Nuclear Plant (SQN), Units 1 and 2. The proposed changes were to revise SQN Units 1 and 2 Technical Specifications (TSs) 3/4.6.5, "Ice Condenser," to increase the total ice weight from 2,225,880 pounds to 2,540,808 pounds.

U.S. Nuclear Regulatory Commission CNL-16-049 Page 2 September 19, 2016 The Reference 1 LAR was submitted to address the issues raised in Westinghouse Nuclear Safety Advisory Letter (NSAL) 11-5, 'Westinghouse LOCA Mass and Energy Release Calculation Issues." The issues identified in NSAL-11-5 affected plant-specific loss of coolant accident (LOCA) mass and energy (M&E) release calculation results that are used as input to the containment integrity response analyses. The changes in the LOCA M&E release calculations and the associated changes to the SQN containment integrity response analyses resulted in TS Limiting Condition for Operation 3.6.12 being non-conservative with respect to the required total ice weight.

The Reference 2 LAR supplement proposed changes to address issues raised in Westinghouse Nuclear Safety Advisory Letter (NSAL) 14-2, "Westinghouse Loss-of-Coolant Accident Mass and Energy Release Calculation Issue for Steam Generator Tube Material Properties." The issues identified in NSAL-14-2, also affected plant-specific LOCA M&E release calculation results that were used as input to the SQN containment integrity response analyses.

On July 13, 2015 (Reference 3), TVA received a request for information regarding Westinghouse lnfoGram IG-14-1, dated November 5, 2014, which stated that the LOCA M&E release analysis methodology used a reactor coolant system (RCS) stainless steel volumetric heat capacity value that was lower than the ASME values.

To address the issue identified in IG-14-1 , TVA will revise the LOCA M&E release calculations and the associated SQN containment integrity response analyses utilizing the new Westinghouse WCOBRA!TRAC model (based on WCAP-17721-P, "Westinghouse Containment Analysis Methodology - PWR LOCA Mass and Energy Release Calculation Methodology," Reference 4). The revised LOCA M&E release calculations and the associated SQN containment integrity response analyses are expected to be completed in May 2018.

Based on discussions with the NRC staff, TVA has decided to withdraw LAR SQN-TS-12-04.

If necessary, TVA will submit a new LAR using the revised analyses. In the interim, the non-conservative SQN TSs are being tracked in the TVA Corrective Action Program and administrative controls have been established in accordance with NRC Administrative Letter 98-10. TVA will provide periodic updates to the NRC regarding schedule progress every six months until the non-conservative TS condition is resolved . The first update will be provided no later than February 28, 2017.

There is one new regulatory commitment contained in this submittal. Please address any questions regarding this submittal to Mr. Edward Schrull at (423) 751 -3850.

Rei[;J!___

~.~ea Vice President, Nuclear Licensing Enclosure cc: See Page 3

U.S. Nuclear Regulatory Commission CNL-16-049 Page 3 September 19, 2016

Enclosure:

Regulatory Commitment cc: (w/Enclosure)

NRC Regional Administrator - Region II NRC Senior Resident Inspector - Sequoyah Nuclear Plant Director, Division of Radiological Health - Tennessee State Department of Environment and Conservation

Enclosure Sequoyah Nuclear Plant, Units 1 and 2 - Withdrawal of Application to Modify Ice Condenser Technical Specifications to Address Revisions in Westinghouse Mass and Energy Release Calculation (SQN-TS-12-04)

Regulatory Commitment Tennessee Valley Authority will provide periodic schedule updates to the NRC for revising the LOCA mass and energy release calculations and the associated SQN containment integrity response analyses every six months until the non-conservative TS condition is resolved. The first update will be provided no later than February 28, 2017.