ML032950134
| ML032950134 | |
| Person / Time | |
|---|---|
| Site: | Davis Besse  |
| Issue date: | 10/21/2003 |
| From: | Hopkins J NRC/NRR/DLPM/LPD3 |
| To: | |
| References | |
| 2003-0761 | |
| Download: ML032950134 (35) | |
Text
NRC FORM 658 U.S. NUCLEAR REGULATORY COMMISSION (9.1999)
TRANSMITTAL OF MEETING HANDOUT MATERIALS FOR IMMEDIATE PLACEMENT IN THE PUBLIC DOMAIN This form is to be filled out (typed or hand-printed) by the person who announced the meeting (i.e., the person who issued the meeting notice). The completed form, and the attached copy of meeting handout materials, will be sent to the Document Control Desk on the same day of the meeting; under no circumstances will this be done later than the working day after the meeting.
Do not include proprietary materials.
DATE OF MEETING The attached document(s), which was/were handed out in this meeting, is/are to be placed 10/21/2003 in the public domain as soon as possible. The minutes of the meeting will be issued in the near future. Following are administrative details regarding this meeting:
Docket Number(s) 50-346 Plant/Facility Name Davis-Besse TAC Number(s) (if available)
Reference Meeting Notice 2003-0761 Purpose of Meeting (copy from meeting notice) Discuss the modification of the high pressure injection pumps.
NAME OF PERSON WHO ISSUED MEETING NOTICE TITLE Jon Hopkins Senior Project Manager OFFICE NRR DIVISION DLPM BRANCH LPD3 Distribution of this form and attachments:
Docket File/Central File PUBLIC 5(919)RNEDORECLDPPRTi FR .R onwasdsgnduig nom NRC FORM 658 (9-IM9) PRINTED ON RECYCLED PAPER This fom was designed using InForms
FrstEnergy Davis-Besse Nuclear Power Statiom Modification. of High Pressure Injection Pumps
.. . . . _ =_ . "_ . _ . _ ..................................................................................................................
Vf " P piA'q Agenda
- Opening Remarks ................ . . Gary Leidich
-Modification Design.-......................... Bob Schrauder
- Analysis and Qualification' Testixn;g .'.....Bob Coward, MPR
- Conclusion .......-........ Gary Leidich Gary Leidich President and Chief Nuclear Officer - FENOC 2
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Opening Remarks TV Gary Leidich President and Chief Nuclear Officer - FENOC 3
Desired Outcome NRC and the public gaini confidence that pump modifications and issociatedltesting and analysis ensure the HPI pumpsvwill-ierform their required safety functions under ail design conditions laz=SM ~~~~~~~~~~~~~~~~~~~~~~~e ff X_ _ _ _ t _
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FkrstEnew Overview
- Background
-Implemented Building Block approach in 2002 that included assuring the health of plant systems
-System Health Assurance identified the High Pressure Injection Pumps as an original design issue since fine particles from the Containment Emergen"cy.Suiip'could poteitially damage the pumps during the loss-of-c0ol0 a6ccident (LOCA) recirculation mode
- Today
-Present how these findings were resolved and provide assurance the HPI Pumps are capable of performing their design function
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L..V S 3
Modification Design Bob Schrauder Director -Support Services 7
High Pressure Injection Pumps 0 .
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- Manufacturer
- Babcock and Wilcox Canada A__... .
-Type
- __4 At
- Horizontal, clcvcn stage centrifugal pumps 6 HP electric motors 60-I-
Hyidrostatic bearing "Design Pressure/Temperature 1" ..-.2000 psig/300°F-
- Dcsign/Manufacture Code ASME Pump & Valve Code, Class 11, November 1968
'Surveillance Test/Inservice Testing
- ASME Operation and Maintenance Code (1995 Edition with 1996 Addenda)
-This design is unique to Davis-Besse in domestic nuclear industry s
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-R " I 1. I 1111= 15904.
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HPI Pump Operational Environment
- Borated Water Storage Tank Operation
-Surveillance Testing
-Initial Post-LOCA mode . :>
- Sump Recirculatioiinnt..ti -
-In post-LOCA reciafi d Peo PI pump suction is from Containment EmegeiSnp through LPI pumps
-Sump may contain debris from LOCA blowdown and containment spray actuation
-HPI Pumps must be capable of operating with debris in the pump flow 9
Nudear PwrStadox October 21,2003 AFrstEnem.
HPI Pump Original Design Issues
- System Health Assurance identified design issues
-Hydrostatic bearing plugging . -
-Bearing orifices areesmaer thah Emergency sump strainer and could beco'm .
-Bearing ptlketic arem -"l""' strainer
-Close clearancew
-Preliminary rot&rdynaics ag~jyse3 suggested increases in clearances due to wearby debrs ouldiead to operation at critical speeds
-Increased clearances will degrade pump hydraulic performance
-Supply path to cyclone separator (seal water) could be smaller than sump strainer and may become plugged 10
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Original Hydrostatic Bearing
- Orifices in supply to hydrostatic bearing pockets arc 0.109 inch diameter
-New containment . \
emergency sump strainer1 e /
has 0.188 inch diameter openings ; \
- Orifices may plug with i 0 debris that passed through sump strainer, degrading ,
bearing performance 1I PW=_0 Ed M~~~IMW_,T_ I l
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Original Hydrostatic Bearing
- Bearing includes tight clearances (0.006 inch to 0.007 inch) at edges of pockets
-Debris in supply water may be larger than clearance and accumulate in the bearing pocket
- Degradation of bearing performance may impact pump operation 12
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Close Clearances Wear
- Pump design includes tight clearances
-Central volute bushing (0.006 inch to 0.007 inch)
-Hydrostatic bearing (0.006 inch to 0.008 inch) i
-Wear rings (0.009 inch to 0.OlO'inch) ,
- Debris in water may increase rate of wear of the fine clearances -'
-Increased clearances could result in operation at critical speeds
-Increased clearances could decrease hydraulic performance capability Suction Wea 13 Ring Discharge Wear Ring MMENOMMOM W -,'7 . 1111- IMP-M 7
8 Fusffinemy Resolution Objective
-Implement a resolution plan that fully resolves HPI pump debris issue that
-Modifies only the HPI pump
-Assures compliance with existing licensing basis, procedures, Updated Safety Analysis Report, and design basis documents
-Meets requirements of Technical Specifications 18
_I._es 9
FustEnegy.
- Modifications
-Install self-flushing straineri;,
on volute to prevent-..>
plugging of hydrostatie, +-: I bearing supply line orifice -, r i
-Move supply line take-off to' II suction side of volute 19 1111 1 111111 IRMIX-NOZERIVIOUROWR 11= 11Ing=
Initial Modification Approach
- Key Assumptions to be verified
-Strainer would be self-flushing and remain clear of debris
-Debris larger than bearing clearance would be crushed by bearing and pass thrioughclearace
-Wear of close clearances_,ould be minimal and uniform
-Pump operation at critical speeds would not cause vibration or other operational challenges 20
- _O 10
Developmental Test Results
- Several key assumptions proved invalid
-Soft, larger debris became lodged in bearing pockets and orifices
-Velocities in volutewere not sufficiientfto keep finer strainers clear
-Wear was greater than anticipated, particularly for soft components
-Close clearances are subject to plugging 21 t,'Mr,'7Arf.;.'.'i,',f,'rW-,-= , IVI.T .....
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FustEneW.
Revised Design Concept
- Three primary load carrying components: hydrostatic bearing, wear rings, and central volute bushing
- Rotordynamic analyses show several acceptable conditions
-Functional hydrostati cbearing and bushing
-Functional hydrostatic bearing and wear rings
-Functional wear rings and bushing
- Use defense-in-depth approach and address all three components to ensure they fimction under debris loading 22 5AFM 101 11
Revised Design Concept (Continued)
- Use 50 mil strainer to protect hydrostatic bearing orifices
- Locate strainer on discharge side of impeller, close to wear ring to,,',
reduce concentration and'size of I: '-
debris reaching hydrostatic , .
bearing
-Wear ring acts as a strainer
- Centrifugal effect on heavier debris maximized
-Discharge side of volute maintains high velocity for all pump flows
-Standard approach used by Pump Suction We ear Guinard for French PWRs -1 Ring Discharge 5 'ear Ring Ai1 I
12
FirstEnerg Revised Design Concept (Continued)
Modify hydrostatic bearing"<',
to improve debris tolerance, Ae,
-Add "escape' grooves to firs ._
pocket -
-Change rectangular pocket to i '< i >
"8"pocket based on Pump N Guinard design "8"Pocket Hydrostatic Bearing 25 111111111 INT'll 1 11 VSEnerg Revised Desigi I Concept (Continu ed)
- Hardface all critical wear ,
surfaces: wear rings,,
F bushing and shaft sle'eje,- '
hydrostatic bearing and, sleeve Suction and Discharge Wear Rings 26 I' - *W4~~~~,. 7.-
45 .
13
Analysis and Qualification Testing
-4J . v Bob Coward MPR Associates 27
_P I-Modification Design Analyses
- Volute stress analysis
- Strainer stress analysis -
-Hydrostatic bearing Ioad cariy'ing' capability and stiffness
- Failure modes and effects analysis
- Hardfaced parts equivalency evaluations 28 14
RstEnerg Volute Finite Element Model 29
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Strainer Finite Element Analysis Stress 30 WOMR1010=11 III - --
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RrsEner Hydrostatic Bearing Analysis 31 A _
Failure Mode and Effects Analysis
- Considered all modifications to pump
- Evaluated potential failure modes for modification design
- Concluded no new failure modes are introduced 32 16
Qualification Testing Overview
- Use separate effects testing to evaluate pump internal components individually
-Avoids contamination concerns
-Addresses parts availability concerns
-More flexible than full pumrp testI Kv
- Key elements of program included:
-Fixture designs match critical characteristics of HPI pump
-Full scale components
-Debris characterization based on Davis-Besse containment
-All testing in accordance with MPR's Quality Assurance Program 33 I'._I,'I,._ "V-_--__. -' - , z--- ' ' :-_
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Qualification Testing Configuration
- Five test loops
-Loop 1 - Suction Wear Ring
-Loop 2 - Discharge Wear Ring
-Loop 3 - Hydrostatic Bearng
-Loop 4 - Central Vo1ute Bushing ..
-Loop 5 - Hydrostatic Beainguppiy Strainer
- 8000 gallon supply tank simulating sump (including debris) supplied Loops 1, 2, 4, 5
-Loop 3 (hydrostatic bearing) supplied through Loop 5 strainer 34
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Qualification Testing Objectives Loop Objectives Suction Wear Ring & Mcasure Clearance Increase Discharge Wear Ring - and Measure Flow Rates Hydrostatic Bearing - Measure Clearance Increase and Confirm Adequate Flow Central Volute Bushing Measure Clearance Increase and Measure Flow Rates Hydrostatic Bearing Supply Confirm Adequate Flow Strainer 35 I~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~-
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Typical Te¶st Loop P28 36 By _~~~~~~~~~~~~~;~ a l*
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FIf iIT Suction Wear Ring Test Fixture d~~~~4~-Z .- i 37 I. ~~~~~,~~~Rlwpww '-t~fl vl~~~~~~~~'
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Test Fixture Equivalency Evaluation
- Design Configuration
- Verify test fixture dimensions and materials match the HPI pump internals
- Flow Fields
- Hydraulic and Cornputational Fluid Dyniamics (CFD) analysis of test fixtures compared to HPI pump
- Operating Conditions - t
- Test flow rates and pressures consistent with HPI pump functions
- Debris Characteristics
- Use types, sizes and quantities of the debris expected in LOCA 39 P login M&A-TaffRUNW.. I U_
CFD Modeling HPI and Loop 5 Pumps HPI Pump Loop 5 Pump 40 F
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CFD Analysis Results is]>
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-llm, 41~~~~~~~~~~~~~~~~1 rstEneWg HPI Pump Operating Conditions
- SBLOCA operating conditions most challenging, but minimal debris
- LBLOCA most challenginjdebnrs, but not needed for short term cooling . :
- LBLOCA long term cooliigi,'(l6ron precipitation control) combines worst case debris with low flow/high head operation - testing performed for these operating conditions 42 F
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Debris Characterization Approach
- Analyses based on debris generation and debris transport analyses for containment sump modification, as well as NRC-sponsored research
- Critical parameters, and their acceptance ranges, are defined for each debris type ; -
- Commercial-off-the-shelf (COTS) materials selected to match critical characteristics
- Debris handling procedure addresses initial loading, sampling, and re-loading 43 IW,,*,'tW_7MTR9,W=W4IWW M"91MMMINIM KIM M ;I ;PPI FustEnergy.
Debris Characterization Analysis
- Considered short term and long term debris generation
- Considered debris transport to sump strainer
- Particle sizes selected to increase pump degradation
- Debris "recipe" includes:
-Fiber (based on quantities after rcm`-oval from containment)
-Rust -
-Qualified and unqualified coatings
-Dirt and dust
-Concrete particles 44 22
FustEnergy.
Conservatisms in Analysis
- No credit for filtering of small debris on sump strainer surfaces
- Particle/fiber sizes biased toward increasing potential for pump degradation
-All miscellaneous fibers assumed to transport to sump
- All unqualified coatings are assumed to fail and become debris in post-LOCA environment 45 I IT_- .- -
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Central Volute Bushing Test Results
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alI2w Central Volute Bus] Test Results ndIl so 25
Hydrostatic Bearing Test Results 9 I.,
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2 21 Days Testing 52 M
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Hydrostatic Bearing Test Results 1J' ~. . . ... ..
3~~~~~~~~~5 77+b-, '7 7 7Jks;
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19sEnewg StrainerTest Results Strainer Test Results111 54 27
Fvsfstnergy Qualification Testing Results Summary
- Suction Wear Ring
-Minimal wear on wear ring and impeller hub
-Little impact on leakage flow .
- Discharge Wear Ring -*
-Minimal wear on wear ring I-
-Abrasive "grooving" on ixmipeller hub from plugging, small wear elsewhere on hub
-Essentially no impact on pump performance 5S
_~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~.. a!l!!
Qualification Testing Results Summary (Continued)
- Central Volute Bushing
-Minimal wear on bushing
-Abrasive wear on shaft sleeve from plugging
-Leakage flow depends on plugging and axial extent of abrasive wear '
- Hydrostatic Bearing 7.
-Minimal wear on bearing
-Abrasive wear on shaft sleeve
-Bearing flow remained adequate (--5% decrease)
- Strainers
-Essentially constant flow throughout test 56 11p WON= Hill 11~~
111% NIM~gm 28
Performance Analyses
- Rotordynamics Analysis
-To demonstrate that vibration levels for the worn condition of all pump parts are acceptable
-Preliminary analysis results show acceptable results
- Hydraulic Analysis
-To demonstrate the pump hydrauli 6performance in the worn condition is acceptable
-Preliminary analysis results show considerable margin 57
_MR-Rotordynamics Analysis Model
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58
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FsE~nery.
Critical Speed Analysis
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Original Hydrostatic Bearing Replacement iydrostatic Bearing 59
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Forced Response Analysis 3 ... ,........ ....
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75% Central 50% Central Volute Bushing Volute Bushing Length Length 60
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Hydraulic Performance Analysis
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50Jl d.0 60 d 00 0 100 200 300 400 600 500 700 a6 600 I1000 61 Da'tJetrB surr~ri October 21,2003 French Experience
- French PWRs use similar class pump for make-up/HPI
- Nuclear Safety Authority requested validation pumps would operate satisfactorily n emergency conditions
-Comprehensive ltestingper 6'&dinJ19804981
-Pump design moieod tlo erance
- Main design features w e
-Moved hydrostatic bearing 'take-offto'discharge side of volute
-Hardfaced close clearances
-Modified hydrostatic bearing pocket design to "H" bearing
-Replaced central volute bushing with hydrostatic bearing 62 Dais-sOsem I'relearPewrStati,,, October 21,2003 31
French Experience (Continued)
- Davis-Besse HPI PuntipnmI't1fi s comparable to French modificati !W'ith' dditipI measures to improve debris tolerance.
63 N ffW34e53tr~tiel October 21,2003
,% P afdrar O F -. - - - J Overall Approach Summary Concern Modifications Testing Analysis IISB *Installed strainer to *Mock-up testing of *Completed structural orifice and filter debris I - strainer demonstrated of pocket *Moved IISB takeoff to' flowolute/strainer plugging low debris 10 - ati¶,' dktiidfS Completed IISB plugging*Includedd Xhydraulic analysis grnciue Id d rist s ap
- rooves in,=,:4,! t~- *Completed evaluation of mock-up fixtures Close *Installed replacement mck+-iPtesting f new *Rotordynamics analysis clearance hardfaced parts to parts determined worn demonstrated worn wear minimize wear condition condition and new HSB
- In-plant testing ofworn are acceptable pump demonstrated *Hydraullc analysis acceptable performance demonstrated worn condition Is acceptable 64 Dev-Resti October 21, 2003 32
Major Project Conservatisms
- Defense-in-depth approach to ensure satisfactory pump performance
- Mock-up testing did not include filtering effect of discharge wear ring for hydrostatic bearing "flow
- Mock-up testing maintained initial debris concentrations for entire test - extreme m'eas'ures were required to prevent settling and hideout
- AII miscellaneous debris assumed to be transportable fiber
- Simulated coating materials in mock-up testing significantly stronger than containment coatings 65
_f _ _ _ E _~~~~~~~~1P' Project Status
- Modification design completed, finalizing design change package
-Mock-up testing completed, finalizing data analysis
- Preliminary rotordynanicj and hydraulic analysis completed, awaiting finalization of test report
- Pump modifications in progress 66 33
Conclusion Gary Leidich President and Chief Nuclear Officer - FENOC 67
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FusI Conclusion
-Modifications, along with associated analysis and testing, demonstrates that t HP Ijiumps will perform their safety functions
- IKIAwm W.F ., -. 1-1. - -
34