ML103470631

Slides for December 2010 Public Meeting

ML103470631
Person / Time
Site:	Browns Ferry
Issue date:	12/13/2010
From:	Tennessee Valley Authority
To:	Division of Operating Reactor Licensing
Gratton C, NRR, DORL, 415-1055
References
Download: ML103470631 (17)

Text

TENNESSEE VALLEY AUTHORITY BROWNS FERRY NUCLEAR PLANT Status of Extended Power Uprate (EPU)

Rockville, Maryland December 15, 2010

Agenda

• Introductions

• Meeting Purpose

• Review BFN Extended Power Uprate Regulatory History

• Future Plans

- Containment Accident Pressure Mitigation

- Steam Dryers

- Schedule 2

Meeting Purpose

• Revive Browns Ferry EPU project license submittal

• Confirm outstanding project scope

• Communicate planned Containment Accident Pressure (CAP) mitigation strategy relative to Draft NRC guidelines

• Communicate plans for Steam Dryers 3

Browns Ferry EPU History

• June 2004: Initial EPU Submittals

• Unit 1 - 100% to 120% OLTP with pressure increase

• Units 2 and 3 - 105% to 120% OLTP

• February 2007: ACRS reviewed Unit 1 analyses for 120% operation

• pp March 2007: Unit 1 approved for 105% operation p

• Included pressure increase

• Units 1, 2, and 3 now at same licensed power level

• September 2009: EPU CAP review placed on hold pending development of CAP guidance

• March 2010: NRC Draft Guidelines on CAP provided 4

EPU Modifications Modification Status U1 U2 U3 Reactor New Main Steam Isolation Valve Internals and Actuators Complete Complete Complete Systems Up-rated Reactor Recirculation Motors / Pumps Complete Complete Complete Replacement Steam Dryers Secondary New Condensate Pumps and Motors Complete Complete Planned 2012 Systems Additional Condensate Demineralizer Vessel Complete Complete Planned 2012 New Condensate Booster Pumps and Motors Complete Complete Planned 2012 Condensate Demineralizer Digital Upgrade Complete Complete Planned 2012 New Reactor Feed Pumps Complete Complete Planned 2012 New Reactor Feed Pump Turbines Complete Complete Complete New Feedwater Heater Nozzles, Relief Valves and #3 Shell Complete Complete Planned 2012 New HP Turbine New Moisture Separator Internals Complete Complete Complete New Generator Bus Duct Coolers and Fans Complete Complete Complete 6

EPU Open Issues

• Containment Accident Pressure (CAP)

• Replacement Steam Dryers (RSD) 7

CAP Mitigation Evaluation

• Based on Draft Guidelines provided, comprehensive engineering analysis was performed to identify and evaluate strategies to address CAP for all events

• Evaluation used Draft Guideline criteria to determine CAP need:

• NPSHR 3% curve for LOCA plus uncertainty adder

• NPSHR 3% curve ffor S Special i lEEventst

• Evaluation conservatively used 4 feet for uncertainty adder 8

CAP Evaluation Results

• Use of NRC Draft Guidelines eliminates CAP for Station Black Out (SBO) event

• Use of NRC Draft Guidelines eliminates CAP for Anticipated Transient Without Scram (ATWS) event

• IImplementation l t ti off NFPA-805 NFPA 805 (including (i l di comprehensive h i safef shutdown analysis upgrade, comprehensive improvements to safe shutdown procedures) is expected to eliminate Appendix R CAP requirement, to submit NFPA-805 LAR March 2012

• Changes to credit improved RHR Heat Exchanger performance eliminates CAP for Long-Term LOCA Core Spray event

• CAP credit needed for Short-Term LOCA event only 9

CAP Evaluation Results contd Long-Term LOCA Core Spray Event:

• RHR heat exchanger performance tests have measured fouling factors significantly better than vendor values used in current CAP analyses

• Revisions required to Generic Letter 89-13 89 13 Heat Exchanger program to reflect use of higher heat transfer coefficient value would credit improved Residual Heat Removal (RHR) Heat Exchanger performance

• Improved RHR Heat Exchanger performance eliminates CAP for Long-Term LOCA Core Spray event 10

CAP Evaluation Results contd Short-Term LOCA Event:

• CAP credit needed for Short-Term LOCA event

• Short-Term LOCA CAP has low risk significance and PRA analysis will be performed

• CAP is required for only short time period of ten minutes

• Low probability of a large break LOCA and simultaneous gross containment failure

• Operation at EPU power levels do not significantly worsen existing CLTP CAP for the short term LOCA event 11

EPU CAP Summary Existing EPU Planned EPU Submittal Submittal Values Values Short-Term LOCA Revised values using draft Current CLTP values

(< 10 minutes) CAP guidelines Core Spray 1.47 psi < 10 minutes 2.0 psi / 8.9 minutes 2.0 psi / 9.7 minutes RHR Intact Loop None Required 0.2 psi / 3.2 minutes 2.7 psi / 9.7 minutes RHR Broken Loop 1.57 psi < 10 minutes 2.1 psi / 9.3 minutes 5.0 psi / 10 minutes Long-Term LOCA (> 10 minutes)

Core Spray 3.0 psi / 22.5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br /> None Required RHR - Containment None Required None Required Cooling Special Events Appendix R (NPSH 3%) 6.1 psi / 27.8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> None Required Station Black Out 1.4 psi / 1.4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> None Required ATWS 1.9 psi / 1.2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> None Required 12

Replacement Steam Dryers

• To improve required stress margins, TVA will replace the existing steam dryers

• RSDs will be designed and analyzed by General Electric Hitachi (contract scheduled to be finalized in early 2011)

• RSD analyses will use GEH Plant Based Load Evaluation (PBLE) methodology

• Analyses will use Main Steam Line (MSL) strain gage data taken at CLTP conditions

• Data for Units 1 and 3 already taken

• Additional data for Unit 2 to be taken Spring 2011 13

Replacement Steam Dryers

• Goal to submit RSD analyses by January 2012

• Lessons learned from ongoing Grand Gulf reviews will be incorporated as required

• Submittal will address all open BFN applicable steam dryer related RAIs from previous reviews

• Plan tto instrument Pl i t t dryer d on llead d unitit only l tto measure performance f d during i

power ascension to EPU conditions

• Will initiate dryer construction following approval of EPU submittal

• Dryer replacement is predicated by successful resolution of EPU CAP 14

Draft Schedule for EPU Submittals

• Steam Dryer analysis and design February 2012

• NFPA-805 LAR (Appendix R Cap elimination) March 2012

• Remaining plans to mitigate CAP March 2012

• Unit 1 Areva fuel analysis for EPU March 2012 NRC Activity

• 18 months for NRC review, ACRS meetings, etc.

• Issue SER for EPU September 2014 EPU Implementation Activities

• Unit 2 EPU Spring 2015

• Unit 3 EPU Spring 2016

• Unit 1 EPU Fall 2016 15

Closing Remarks

• We will design and install new steam dryers

• We plan to eliminate requirement for CAP for all accident scenarios except Short Term LOCA

• W We will ill ffollow ll up and d iissue a kkey assumptions ti lletter tt iin JJanuary based on discussions today regarding our planned strategy to mitigate/ eliminate Containment Accident Pressure

• We will maintain an open dialogue of communication in the form of a bi-weekly telecon with project manager 16

Questions/Comments?

Quest o s/Co e ts 17