ML15225A377

Tennessee Valley Authority Presentation to NRC on Tpbar LAR 8-12-15

ML15225A377
Person / Time
Site:	Watts Bar
Issue date:	08/12/2015
From:	Tennessee Valley Authority
To:	Dion J Watts Bar Special Projects Branch
Dion J, NRR/DORL/LPWB, 415-1349
References
Download: ML15225A377 (17)

Text

Watts Bar Nuclear Plant Unit 1 TPBAR Loading Increase License Amendment Request Alignment Meeting

Agenda

• Introduction and Purpose

• WBN Unit 1 TPBAR Loading Plans

• Licensing Activities Schedule

• Timeline for WBN Unit 1 TPBAR Program

• Proposed Technical Specification Changes

• Post-LOCA Subcriticality Analysis

• Radiological Analysis

• NRC Review with TVA and DOE Support

• Summary 2

Introduction

• TVA requested a change to the Watts Bar Nuclear Plant (WBN)

Unit 1 Technical Specifications to increase the number of Tritium Producing Burnable Absorber Rods (TPBARs) that can be irradiated from 704 to 1792

• TVA requested NRC approval by August 31, 2016, to support an increased TPBAR loading in Cycle 15 (spring of 2017) for DOE National Nuclear Security Administration (NNSA) needs 3

Purpose

• Provide a high level overview of the License Amendment Request (LAR)

• Discuss the schedule of the LAR review to meet the NNSA need date

• Offer TVA and DOE support of NRC technical reviews 4

WBN Unit 1 TPBAR Loading Plans Cycle Date TPBAR Loading Tech Spec Limit C13 April 2014 704 704 C14 October 2015 704 704 C15 March 2017 1104 1792*

C16 October 2018 1504 1792*

C17 April 2020 1792 1792*

• Proposed LAR 5

Licensing Activities Schedule 1792 TPBAR License Amendment Key Milestones August 2015 June 2015 Review February February2016 2016 July 2016 August 2014 Submit LAR Kickoff NRC Management March 2016 Start August 2016 April 2017 Pre-Application March 2015 Supplemental Meeting Meeting on Start Cycle 15 Cycle 15 Fuel NRC SER for Cycle 15 Meeting with NRC Submit LAR Response with NRC Review Status Fuel Design Fabrication 1792 TPBARs Startup April 2015 - August 2016 March 2016 - October 2016 NRC Review Fuel Design & Delivery January 2015 January 2016 January 2017 July 2014 June 2017 6

Timeline for WBN Unit 1 TPBAR Program

• May 1996 - DOE/NRC Memorandum of Understanding (MOU) formed the basis for NRC review and consultation on possible use of Commercial Light Water Reactors (CLWRs) for producing tritium

• Oct 1996 - TVA agreed to irradiate 32 TPBARs in four Lead Test Assemblies (LTAs) at WBN Unit 1

• May 1997 - NUREG-1607 (LTAs) issued

• Sept 1997 - WBN Unit 1 Amendment 8 (LTAs) issued

• Oct 1997 - 32 TPBARs loaded in Cycle 2 7

Timeline for WBN Unit 1 TPBAR Program (cont.)

• Sept 2002 - WBN Unit 1 Amendment 40 approved up to 2304 TPBARs

• Oct 2003 - WBN Unit 1 Amendment 48 reduced loading to 240 TPBARs to address post-LOCA subcriticality margin issue

• Oct 2003 - 240 TPBARs loaded in Cycle 6

• Mar 2005 - TVA notified NRC of interim cumulative TPBAR tritium release limits

- While higher than projected permeation rates were investigated

• Apr 2005 - 240 TPBARs loaded in Cycle 7 8

Timeline for WBN Unit 1 TPBAR Program (cont.)

• Nov 2006 - 240 TPBARs loaded in Cycle 8

• Jan 2008 - WBN Unit 1 Amendment 67 approved up to 400 TPBARs

• Mar 2008 - 368 TPBARs loaded in Cycle 9

• May 2009 - WBN Unit 1 Amendment 77 approved up to 704 TPBARs

• Oct 2009 - 240 TPBARs loaded in Cycle 10

• May 2011 - 544 TPBARs loaded in Cycle 11 9

Timeline for WBN Unit 1 TPBAR Program (cont.)

• Oct 2012 - 544 TPBARs loaded in Cycle 12

• May 2014 - 704 TPBARs loaded in Cycle 13

• Jan 2015 - TVA notified NRC of updated program controls to remove interim measures for permeation while maintaining doses and release concentrations within regulatory requirements

• Oct 2015 - 704 TPBARs planned for loading in Cycle 14 10

Current License Amendment Request

• Pre-application meeting with NRC on August 14, 2014

• LAR submitted to NRC on March 31, 2015

• Correction letter submitted to NRC on April 28, 2015

• Provided supplemental information in letters dated May 27, 2015, and June 15, 2015, in response to NRC requests

• NRC accepted LAR for review on June 26, 2015 11

Proposed Technical Specification Changes

• Revise Technical Specification 4.2.1 to reflect new upper limit of 1792 TPBARs

• Revise Surveillance Requirement 3.5.1.4 to remove dependence of accumulator boron concentration on number of TPBARs

• Revise Surveillance Requirement 3.5.4.3 to remove dependence of RWST boron concentration on number of TPBARs Number of TPBARs Boron Concentration Ranges 0 - xxxx > yyyy ppm and < zzzz ppm 12

Post-LOCA Subcriticality Analysis

• Post-LOCA subcriticality analysis method consistent with method previously used in WBN Unit 1 Amendment 77 with the following key changes:

- Eliminated 40 gpm dilution source in containment sump (requires plant modifications)

- Updated time-dependent lithium leaching rate based on testing

• RCS boron concentration reduced by increased Integral Fuel Burnable Absorber (IFBA) loading

• Results demonstrate sufficient margin for 1792 TPBARs 13

Radiological Analysis

• Radiological analysis in WBN Unit 1 Amendment 40 assumed 2304 TPBARs and permeation rate of 1 Ci/TPBAR/year

• Current LAR supported by new radiological analysis for:

- Realistic scenario of up to 1900 TPBARs at 5 Ci/TPBAR/year

- Bounding (Design Basis) scenario of up to 2500 TPBARs at 10 Ci/TPBAR/year

• Regulatory criteria in 10 CFR Part 20, Part 50.67, Part 50 Appendix I, and Part 100 are all satisfied 14

NRC Review with TVA and DOE Support

• Due to the importance of meeting the NNSA need for increased TPBAR irradiation in WBN Unit 1 Cycle 15, TVA requests essential completion of NRC technical reviews prior to initiation of fuel and core design activities on March 2, 2016

• TVA and DOE will provide any support needed for expeditious technical reviews

- TVA and DOE are willing to send technical experts to meet with NRC reviewers to provide any needed background information or discussion of the various LAR sections

• TVA requests at least monthly updates from the NRC Project Manager regarding the progress of the technical reviews 15

Summary

• LAR requests increased TPBAR loadings beginning with WBN Unit 1 Cycle 15 to meet NNSA needs

• LAR addresses post-LOCA subcriticality margin, required plant modifications, lithium leaching rates, and radiological analysis

• TVA and DOE offer technical support for NRC reviewers

• TVA requests monthly progress updates from NRC Project Manager

• TVA requests NRC technical reviews near completion by March 2, 2016

• TVA requests NRC approval by August 31, 2016 16