ML071980284
| ML071980284 | |
| Person / Time | |
|---|---|
| Site: | Susquehanna  |
| Issue date: | 07/19/2007 |
| From: | Susquehanna |
| To: | Office of Nuclear Reactor Regulation |
| Guzman R, NRR/DORL, 415-1030 | |
| References | |
| Download: ML071980284 (27) | |
Text
Non-proprietary Version Susquehanna Steam Dryer Replacement NRC Meeting June 29, 2007 Rockville, MD PP Non-proprietary Version Steam Dryer Replacement Ppi Agenda
- Overview of SSES CPPU Steam Dryer Licensing and Design Approach
- Corrective Action Status
- Replacement Dryer Design Overview
- Steam Dryer Instrumentation Plan
- Power Ascension Test Plan/Start-Up Limits 2
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Non-proprietary Version Overview
" Steam dryer licensing basis is conservative and meets ASME fatigue limit of 13,600 psi The as fabricated replacement steam dryer will have reduced stress intensities and increased margins to the ASME fatigue limit
" The revised FEM provides results less that the ASME fatigue limit
" Replacement dryer designed for CPPU conditions
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Improved dryer joint/weld design and fabrication techniques Design and fabrication conducted under 10CFR50, Appendix B
" Unit 1 steam dryer instrumented for 107% CLTP Demonstrates structural adequacy of new steam dryer design Validates steam dryer. analysis tools
" Power ascension test program Slow and deliberate Confirms no acoustic resonances at 114% CLTP Allows validation of analysis and steam dryer design prior to full CPPU I operation Confirms acceptability of steam dryer up to full CPPU conditions Provides for communication to NRC Non-proprietary Version CPPU Dryer Licensing Approach Based on conservative steam dryer design Stresses benchmarked to 1985 strain gagedata Assumes same weld details as used on current dryer Does not include fabrication stress reduction techniques Power ascension test plan overview Acceptance criteria based on 13,600 psi ASME fatigue limit MSL start-up limit curves based on submitted stress report Unit 1 steam dryer instrumented (strain, pressure, & acceleration) for operation up to 107% CLTP Unit 1 107% CLTP acceptance criteria (values) based on final fabricated steam dryer and steam dryer instrumentation data MSL start-up limit curves validated by steam dryer instrument data and revised as necessary Unit 1 and Unit 2 full CPPU acceptance criteria based on validated MSL start-Up limit curves Summary reports provided to NRC Post implementation inspections 4
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Non-proprietary Version CPPU New Dryer Design Approach
- Based on specific Susquehanna plant steam dryer data New steam dryer design Improved structural design Designed and fabricated under 10CFR50, Appendix B Fabrication utilizes stress reduction techniques Approach will be validated Start-up testing
- Measure actual dryer stresses and loads
. Validate ACM load definition Periodic inspections Design, of Record Revised stress analysis incorporating data from steam dryer instrumentation Incorporate stress reduction fabrication details into revised analysis Updated stress analysis becomes the steam dryer design basis Non-proprietary Version GE CORRECTIVE ACTION
-REPORT Susquehanna Steam Dryer Finite Element Model Input Condition 6
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Non-proprietary Version Corrective Action Overview Support lug locations misplaced
- Under lifting rods for most dryers
- Negligible impact on component mode shapes
- Minor impact on dryer stresses Corrective actions to assure quality
- Internal GE reverification of FE model
- PPL/3rd party review of FE model
- No additional discrepancies found-7 Non-proprietary Version 8
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Non-proprietary Version 10 S
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Non-proprietary Version orrective Action impact - Support Lug Stress Results Impact Limiting Component
-((I Minimum stress margin at full CPPU
[I1 12 6
Non-proprietary Version REPLACEMENT STEAM DRYER OVERVIEW 13 Non-proprietary Version Replacement Steam Dryer Overview Utilized OE from Quad Cities and Dresden replacement steam dryers Overall Design Approach
- Maintain basic geometry Load definition development remains applicable
- 1985 instrumented dryer measurements
- 2006 main steam line measurements MSIV slow closure testing 14 7
Non-proprietary Version Replacement Steam Dryer Overview Overall Design Approach Improve fabrication details to reduce or eliminate stress intensities
" Eliminate surface cold working
" Weld factor optimization
- Full penetration welds
- Minimize plate thickness mismatches
" Move or eliminate welds from high stress locations
" Use extruded and preformed sub-components
" Solution anneal sub-components
" Design and fabricated under 10CFR50, Appendix B 15 Non-proprietary Version Current Susquehanna Dryer 16 8
Non-proprietary Version Replacement Susquehanna Steam Dryer 17 Non-proprietary Version 18 18 9
Non-proprietary Version 20 10
Non-proprietary Version 21 Non-proprietary Version 22 11
Non-proprietary Version 23 Non-proprietary Version 24 24 12
Non-proprietary Version 2]
25 Non-proprietary Version 2]
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Non-proprietary Version STEAM DRYER INSTRUMENTATION PLAN 28 14
Nan-proprietary Version Steam Dryer Instrumentation Plan (PLA-6176)
Vibration Measurement Program Goals
- Validate'the structural adequacy of the replacement steam dryer design under CPPU conditions for first two steps (107% CLTP)
- Validate load definition and structural analysis models used for the full CPPU analysis
- Validate the main steam line strain gage limit curves Non-proprietary Version Steam Dryer Instrumentation Plan
, Steam dryer strain gages Primary instrument for monitoring structural response (Unit 1, first two CPPU steps)
- Steam dryer accelerometers Monitor dryer rocking, mechanical vibration from recirculation pump vane passing frequency (Unit 1, first two CPPU steps)
Provides backup to strain gages for structural response Steam dryer pressure sensors Benchmark pressure load definition (Unit 1, first two CPPU steps)
Provides backup to strain gages Main steam line strain gages Primary instrument for monitoring structural response (Unit 1, third and fourth CPPU steps and all Unit 2 steps) 30 15
Non-proprietary Version I]
31 3on-proprietary Version 32 16
Non-proprietary Version 3]
33 Non-proprietary Version 34 17
Non-proprietary Version I3 35 Non-proprietary Version 36 36 18
Non-proprietary Version I]
37 Non-proprietary Version
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"38 19
Non-proprietary Version 1]
39 Non-proprietary Version Main Steam Line Sensor Summary
" Two locations monitored per steam line
" Four strain gauges per location
" Total of 32 strain gages installed on four steam lines per unit 40 20
Non-proprietary Version Main Steam Line Strain Gauge Locations Up-tm S9o L.
Gage Location Dowasuum 5S".
Gagc Location Dead-He~aded Leg Direto Length MSL A (f)
MSL B (ft)
MSL C (f)
MSL 0 (ft)
Distance from steam dome to 22, 22.B 22..
228 upstream SG locatio (L,)
Di.tencý fron ntnern do.e to
. 52,7 49.6 40.3 52.6 do-w-nsnem SG location (L2)
Distr from steam dome to dead-54.4 NA NA 54.4 h 8eaded0 loo a tion (LO(
Length of dead-eaded leg (L) 24.1 NA NA 24.2 41 Non-proprietary Version Main Steam Line Strain Gauge Acceptance Criteria
" Based on 80% CLTP slow MSIV closure data and 100 CLTP data
" Base data is used to develop baseline curves for each MSL location
" Limit curves developed from baseline curves
- Baseline factored by ratio of ASME endurance limit to peak dryer stress intensity
- Bias and uncertainty included in calculation of peak stress
- Assessments based on frequency dependent uncertainty factors
- The baseline factor is calculated for multiple high stress locations to assureit is limiting 42 21
Non-proprietary Version POWER ASCENSION TEST PLAN 43 Non-proprietary Version Power Ascension Test Plan (PLA-6176) 3 Main Elements
- Slow and deliberate power ascension
" Defined hold points
" Time allowed for monitoring and analysis
- Monitoring, analysis, and trending program
- Steam dryer instrumentation
- Main steam line strain gages
- Piping accelerometers
. Moisture carryover
- Post CPPU monitoring and inspection program to verify dryer and piping performance above CLTP conditions 44 22
Non-proprietary Version Power Ascension Test Plan Slow Deliberate Power Ascension
- Obtain baseline observations at 100% CLTP
- Maximum hourly power increase restriction -1 %
CLTP per hour (-34.8 MWt)
- During power increases, obtain steam dryer instrument (Unit 1 only), main steam line strain, and piping vibration data at each 3.5% power ascension step.
- Each 3.5% power ascension step (-122 MWt)
- Compare strain and vibration data to acceptance criteria
- Obtain/ evaluate moisture carryover data
- Perform plant walk downs
- Review data evaluation and walk down results 45 Non-proprietary Version Power Ascension Test Plan Steam Dryer Monitoring and Analysis
- Level 1: Allowable Stress Exceeded (13,600 psi)
- Action - Reduce power level to previous acceptable level
- Level 2: Low Margin to Allowable Stresses (11,000 psi)
Action - Hold at current power and re-evaluate
" Steam dryer pressures and MSL strain measurements used to validate and benchmark analytical tools
" Unit 1, 3 rd and 4th steps and all Unit 2 steps monitored using MSL strain measurements MSL limit curves updated after benchmark against steam dryer instrument data 46 23
Non-proprietary Version Power Ascension Test Plan Steam Dryer Monitoring and Analysis
" MSiV Slow Closure Test Measurements taken at -80% CLTP to simulate 107% CLTP Benchmark composite pressure load definition used in FEA Measurements taken at -85.5% CLTP to simulate 114% CLTP
- Confirm the "no acoustic resonance" prediction
- Confirm power scaling factor used to calculate full CPPU stresses
" Increased Core Flow Measurements taken at 107% CLTP power, increased core flow range 100 - 108 MIb/hr
- 1 or 2 Mlb/hr steps
- Benchmark and evaluate recirculation vibration load definition used in FEA
- Moisture Carryover Moisture carryover measurements taken at each 3.5% power ascension step over 100% CLTP
- Acceptance criterion < 0.1% by weight
- Action - Hold at current power level and re-evaluate 47 Non-proprietary Version Power Ascension Test Plan Steam Dryer Monitoring and Analysis Unit 1 at 107% CLTP Validate, benchmark load definition and structural analysis analytical tools
- Validate, benchmark CPPU scaling factor Limit curves will be validated on Unit 1 measurements at 107% CLTP Validated MSL power ascension limit curves will be used for ascension to 114% CLTP for Unit 1 3rd and 4 th steps, and all Unit 2 steps Monitored using MSL strain measurements 48 24
Non-proprietary Version Power Ascension Test Plan Post CPPU Monitoring and Inspection Program
- Moisture Carryover and Plant Parameters
- Per station operating procedures
- Strain gage/Accelerometer Monitoring
- Dryer, MSL data collection as appropriate during remainder of operating cycle as long as instrumentation remains operable
- Steam Dryer Monitoring and Inspection
" Plant parameter monitoring during operation
- Dryer inspections during refueling outages per BWRVIP-139
" Inspections and Walk Downs 49 Non-proprietary Version Power Ascension Test Plan NRC Communication Written reports on steam dryer upon completion of test program for each CPPU fuel cycle will be forwarded to NRC staff
- Relevant data collected at each power step
- Comparisons to performance criteria (design predictions)
- Steam dryer structural integrity monitoring evaluations
- Evaluations or corrective actions required to obtain satisfactory dryer performance Reports will be provided for
- Unit 1 at 107% CLTP
" Unit2 at 114% CLTP
" Unit I at 114% CLTP 50 50 25
Non-proprietary Version Power Ascension Test Plan Summary Slow and deliberate power ascension New Steam Dryers Dryer on Unit 1 instrumented for 107% CLTP uprate
- Steam dryer strain gages used for Unit 1 107% CLTP acceptance criteria MSLs on both units instrumented Methods benchmarked to in-plant measurements before proceeding to full CPPU Main steam line strain gages used for Unit 1 114% CLTP and Unit 2 114% acceptance criteria Provides feedback to the NRC Non-roprietary Version Susque anna Steam Dryer Program Summary
" Steam dryer licensing basis is conservative and meets ASME fatigue limit of 13,600 psi
" The as fabricated replacement steam dryer will have reduced stress intensities and increased margins to the ASME fatigue limit
" The revised FEM provides results less that the ASME fatigue limit
" Replacement dryer designed for CPPU conditions
((
1]
Improved dryer joint/weld design and fabrication techniques Design and fabrication conducted under 10CFR50, Appendix B
" Unit 1 steam dryer instrumented for 107% CLTP Demonstrates structural adequacy of new steam dryer design Validates steam dryer analysis tools
" Power ascension test program Slow and deliberate Confirms no acoustic resonances at 114% CLTP Allows validation of analysis and steam dryer design prior to full CPPU operation Confirms acceptability of steam dryer up to full CPPU conditions Provides for communication to NRC 52 26
Non-proprietary Version Additional Questions?
53 27