ML072770508

10/3/07 Meeting Handout, Steam Dryer Evaluation Approach for Monticello Extended Power Uprate (Epu).

ML072770508
Person / Time
Site:	Monticello
Issue date:	10/03/2007
From:	Nuclear Management Co
To:	Office of Nuclear Reactor Regulation
tam P S, NRR/ADRO/DORL, 415-1451
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ML072840499	List: ML072770508 ML072780599
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TAC MD5531
Download: ML072770508 (24)

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c NMucearExcel ,ommitted to Nuclear Excellence Steam Dryer Evaluation Approach for Monticello Extended Power Uprate (EPU)October 3, 2007//Commfe Nto Agenda itroductions"bjectives lonticello Steam Dryer Background idustry EPU Experience with Dryers idustry Dryer Evaluation Approach lonticello Dryer Evaluation Approach Legulatory Guide 1.20 ,ummary and Conclusions

/rf 2 Objetact iv es resent approach for demonstrating team dryer structural integrity)btain NRC feedback Ieiterate future activities S //O N. -3 lonticello Steam Dryer Background lant: GE 1965 Product Line (BWR-3), 206 inch reactor pressure vessel ryer: GE 1965 Product Line, Square Hood Similar to original Vermont Yankee dryer Steam dryer licensing basis accident is main steam line break outside of containment

/Conmfe kN 4 JjjiIZ 4 lonticello Steam Dryer Background This bank partitioned into two sections with flows in opposite directions Dryer Drain Pipe--~Upper Support Ring titoed to/Nuler Excellence Channel for Guide Rod///5 lonticello Steam Dryer Background Steam Dryer Inspection

-In accordance with Boiling Water Reactor Vessel Internals Project (BWRVIP) 139-Exterior and interior inspected No structurally significant flaws identified CommitW to Me calove w. I\%,6 Steam Dryer Industry Experience

'ifferent steam dryer evaluation iethods applied for EPU idustry realization that consistent team dryer analysis methodology ceded Committd to NucsIe r we/ 7 idustry Dryer Evaluation Approach PRI and BWRVIP initiative:

-Steam dryer evaluation methodologies guidance document (planned submittal December 2007)Continuum Dynamics Incorporated (CDI)specific methodology topical report (planned -.--__submittal March 2008)/C 8

Dryer Evaluation Approach Vlonticello approach will be consistent vith:-Other recent applicants

-Draft EPRI and BWRVIP guidance document-Draft CDI topical report//N. M nticello Dryer Evaluation Approach.pproach overview-Screening analysis for loads generated by resonant main steam branch lines-Acoustic Circuit Model (ACM) based on main steam line strain gages using CDI's proprietary methodology

-Current Licensed Thermal Power (CLTR)dryer load definition based upon stra!n gage data ..... u\,/ NMOK I)". 1 ~10

)nticello Dryer Evaluation Approach)proach overview EPU load definition based on strain gage data at CLTP scaled up to reflect EPU conditions Load definition uncertainties consistent with recent EPU evaluations Steam dryer Finite Element Analysis (FEA)performed in frequency domain using 1%structural damping U Limit curves for EPU power ascensiOp

-N -N.ComnuligA to MAJIiiZje 11 m onticello Dryer Evaluation Approach OAonticello Screening Analysis-Similar to EPRI/BWRVIP guidance document-Branch lines larger than three inches evaluated-Preliminary calculations show margin to onset of resonant modes-1/8 scale model to add confidence to analytical screening method/12 onticello Dryer Evaluation Approach\coustic Circuit Model-Model has been used for steam dryer load definitions in prior EPU applications

-Revision 4 more accurately models low frequency loads-Uncertainty and bias applied consistent with recent analyses to NU JiZIL". 13 Inticello Dryer Evaluation Approach ACM Load Definition

-Uses pressure pulsations from steam lines-Translates steam line pressure pulsations to the steam dome-Combines four steam line pressure time histories to produce a pressure time history for the steam dryer surface -/14 onticello Dryer Evaluation Approach kICM load definition

-Based on strain gage data-Two locations measured on each steam line-Locations selected to maximize signal to noise ratio at the critical frequency for Monticello N- ..~/NCommitted so Nudeat Ex1.. ..'\'.15 onticello Dryer Evaluation Approach 3train Gage Measurements

-Measure hoop stress-Hoop stress correlated to pressure-Strain gages* mounted in pairs* wired in a half bridge arrangement

-Eight strain gages per location" maximize accuracy" provide redundancy N N.Committed to Nuear4Exci

)16/

)nticello Dryer Evaluation Approach N I--Upper Strain Gage Lower Stra~ri Gage Typical Strain Gage Lines (MSL-C Locations shown)on MST N N Commitd 1o Akxý"r ExA " 17

)nticello Dryer Evaluation Approach-.PU Load Definition

-CLTP load definition scaled up" by flow squared relationship or" from scale model testing-Uncertainty approach prescribed for the ACM will be applied to EPU load definition after CLTP load definition is scaled up/N1 Commitedl to Eo*ne 18 onticello Dryer Evaluation Approach 3team Dryer Finite Element Analysis-ANSYS-10 Finite Element Model in frequency domain-Structural damping is one percent over the entire frequency range-Avoids difficulties associated with Rayleigh damping anchors-Avoids difficulties associated with time domain convergence

-Uses a significantly larger sample of plantd-ata-----.

-Plus or minus 10 percent frequency shifts in 2.5 percent steps-Consistent with previous submittals iNM i ~~~ComnJe to Ku.arx 1/19 onticello Dryer Evaluation Approach:ower Ascension Limit Curves-Generated to limit steam dryer maximum stress levels during power ascension-Based on maximum stress levels predicted from dryer FEA frequency shifts-Level 2 criteria to be 80 percent of ASME Section III material endurance limit (10,880 psi)-Level 1 criteria to be 100 percent of ASME Section III material endurance limit (13,600psi)-.

CommJU\./20 Regulatory Guide 1.20 1.20, Revision 3 March 2007-Added guidance for EPU Steam Dryer analyses-Emphasizes vibration and acoustic phenomena effects on other components

• Safety/Relief Valves (S/RVs)* Thermowells and sample probes-Monticello approach has accounted ,for-RG 1.20///f COMmht4I Ic 2 Z 21 Regulatory Guide 1.20 Vibration and Acoustic Phenomena on Dther Components

-Demonstrate acoustic resonance not present for S/RVs-Calculate Flow Induced Vibration (FIV) loads on other components using accepted methodologies

-Power Ascension monitoring" Inaccessible MS and FW piping instrumented with accelerometers" Accessible components monitored by walkdowns// , N2 1,16d 10 IA Ex00-e" 22 Summary and Conclusions Steam Dryer Evaluation Approach Summary S- Incorporates industry experience

-Consistent with current EPU submittals

-In line with ongoing EPRI/BWRVIP work Schedule-Draft steam dryer results presentation to NRC (proposed December 2007/January 2008)-Final steam dryer evaluation submitted with EPU LAR (first quarter 2008)Questions/Discussion-- -J\, N23,.. ..:2 3 Overall Proj.ect Time Line 2007 2008 2009 2010 2011 FIV Monitoring FIV FIV Mods for EPU LJ Monitoring Monitoring V Submittal NRC AS & Stability NRC Review of PRNMS Approval n III LAR Prep & Stability Option III V Submittal VNRC Approval V Submittal NRC DSS-CD Stabili y NRC Review Approval Solution LAR PreI*V Submittal V NRC MELLLA+ LA NRC Review Approval Prep AL EPU Phase I & PRNMS Installation A EPU Phase I1 n