ML103470631
| 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 2
- Future Plans
- Containment Accident Pressure Mitigation
- Steam Dryers
- Schedule
Meeting Purpose
- Revive Browns Ferry EPU project license submittal
- Confirm outstanding project scope 3
- Communicate planned Containment Accident Pressure (CAP) mitigation strategy relative to Draft NRC guidelines
- Communicate plans for Steam Dryers
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 March 2007: Unit 1 approved for 105% operation 4
pp 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
EPU Modifications
Modification Status U1 U2 U3 Reactor Systems New Main Steam Isolation Valve Internals and Actuators Complete Complete Complete Up-rated Reactor Recirculation Motors / Pumps Complete Complete Complete Replacement Steam Dryers Secondary Systems New Condensate Pumps and Motors Complete Complete Planned 2012 Additional Condensate Demineralizer Vessel Complete Complete Planned 2012 6
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
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%
f S
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8 NPSHR 3% curve for Special Events Evaluation conservatively used 4 feet for uncertainty adder
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 I
l t ti f NFPA 805 (i l di h
i f
9 Implementation of NFPA-805 (including comprehensive safe 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
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 Heat Exchanger program to Revisions required to Generic Letter 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 11 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
EPU CAP Summary Existing EPU Submittal Values Planned EPU Submittal Values Short-Term LOCA
(< 10 minutes)
Current CLTP values Revised values using draft 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 12 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 Cooling None Required None Required 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
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) 13 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
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 Pl t
i t
t d l
d it l t f
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14 Plan to instrument dryer on lead unit only to measure performance during power ascension to EPU conditions Will initiate dryer construction following approval of EPU submittal Dryer replacement is predicated by successful resolution of EPU CAP
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 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
ill f ll d i k
ti l tt i
J We will follow up and issue a key assumptions letter in January 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?
17 Quest o s/Co e ts