ML20058E697
| ML20058E697 | |
| Person / Time | |
|---|---|
| Site: | Quad Cities  |
| Issue date: | 10/26/1990 |
| From: | Phillips M, Wright G NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | |
| Shared Package | |
| ML20058E690 | List: |
| References | |
| 50-254-90-19-MM, 50-265-90-19, NUDOCS 9011070276 | |
| Download: ML20058E697 (38) | |
See also: IR 05000254/1990019
Text
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. , , I =,n Y U 1g, ,i ' U.S. NUCLEAR REGULATOP,Y COMMISSION' , REGION 111 Reports No.- 50-254/90019(DRS); No. 50-265/90019(DRS) _ -Docket Hos. 50-254; 50-265 Licenses No. DPR-29; DPR-30 -Licensee:: Commonwealth Edison ,0 pus' West III
- 1400 Opus Place
-l
- Downers Grove,-IL -60515
' f acility. Name: Quad Cities Nuclear Station, Units 1 and 2 Meeting Location: .. Region-111 Office, Glen Ellyn , Illinois I - Meeting Conducted: September 25, 1990 , . .. . 1 , Type of Meeting: Management meeting Meeting Facilitator: N/Jmt -[ot_ /o/>f/ f o ' M. P.'. Phillips, Chief .Date- ,'
-Operation 1'ProgramsSection . ? Approved By: [/k/ .. /6[26{f'd '
,- ' f . C. Wrighti, Chief Date ., Operations Branch q deeting Summary ~ Meeting'on September 25, l1990--(Reports' No. 50-254/90019(DRS); No. 50265/90019(DRS)). ,, ' Matters Discussed:. 'Ihe corrective actions taken.in response-to v.iolation- 1 - , LNo..50-254/89024-02(DRS);.No. 50-265/89024-02(DRS)'regarding repetitive ifailures?in the local leak rate test program at the Quad, Cities Station. , a fj o , . , I ' t , L il . y i j i , 9011070276 901026' ~ PDR- ADOCK 05000254
- Q
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t: bs j,5 %' REPORT DETAILS 1. Attendees-- Commor. wealth Edison ! D. Galle, Vice President, BWR Operations ! N. Kalivianaks, General Manager, BWR Operations i R. Bax, Station Manager, Quad Cities W. Fanchen, BWRSD, Downers Grove D. Gibson. Regulatory Assurance, Quad Cities
'J. Glover,~PSD
T._Kovach, Nuclear Licensing Manager i < 1 L C.~Moerke,=BWRSD, onsite ( R..Radtka, Licensing i ! R. Robey, Technical: Superintendent, Quad Cities E. Rowley, BWRSE, Downers Grove R.~Stols, Licensing Admi'nistrator U. S. Nuclear Regulatory Commission H. Miller, Director, D_ivision of . Reactor Safety, Rlli- G.' Wright, Chief, Operations Branch, Rlli ' W..Shafer, Chief, branch, I, DRP Rlli M;.; Phi 111ps,: Chief, Operational Programs Section, R111' F. Maura, Reactor Inspector -Rlli- _{ , , P.'Lougheed, Reactor Inspector, Rlll ' t
- J.
- Kudrick? Section Chief, _ Plant : Systems Branch, NRR
L 2.- ' September 25, 1990 Meeting
~ As a result of the re)etitive failures of the. quad Cities-Nuclear Station a " ' L to pass the localflea k rate rest's (LLRTs) since 1974 or containment 1 - i ? integrated leak-rate: test (CILRT) since approximately-1980,:as most -l a Lrecently documented in'NRC Inspection Report Nos. 50-254/89024(DRS); ' " 50-265/89024(DRS); a meeting.was;heldcin the. Region 111: office <in- iGisn E11ynJ111nois'on September 25, 1990. 1'q , , . lThe- purpose of;thisl meeting was; to discuss' the corrective actions-that- i ' ~ he station' intended.to takelin. order to ensure that future LLRTs and'- 1 t - CILRTs would meet-the acceptance. criteria.: After brief opening remarks, 'the NRC: presented a graph whicheshowed the-Quad Cities LLRT.results , (maximum pathway) for both Units since 1974. TheLtables from which the- -t , , graph?was generated, are included in Attachment A., These tables were ! previously; included:in-Inspection Reports No. . 50-254/89024(DRS);- l 150-265/89024(DRS),:minu's the. leakage totals.
< m: - ! . L -The licensee then presented its proposed corrective actio'ns.- The focus
. of_the presentation was'on-those penetrations / valves identified by the. }{ " o r ' h l 4 2 .- L. . u
. ' . . y; t inspectors in the inspection reports as repetitive failures, and the s actions taken to reduce'their leakage rates. This presentation was i ' basically similar to that provided in the initial response to the violation (letterdatedAugust 17,1990). Slides used are included in , Attachment 2. - Mr. H. Miller contacted Mr. N. Kalivianaks of the licensee's staff on . October 3, 1990, to present the results of the NRC staff's review of the ' licensee's proposed actions. The staff considered the actions planned 'and being taken with respect to the selected valves discussed in the -September 25, 1990, meeting to be reasonable. However, the NRC staff expressed concern about Commonwealth Edison's plan to take no action on - the remaining valves until a comprehensive assessment of valve ' maintenance performance historyis completed in its entirety. The staff felt that the licensee should review the data on valve performance h diready in hand to determine what,-if any, maintenance might be prudent during this upcoming outage - that is, not wait.until all precise aspects - of the assessment are complete before anything is done. These concerns are rooted in the greater than ten year history of penetration failures _. t - .at the end of operating cycles which indicate that containment- - performance at some point in each of these cycles has significant1y' -[ fallen below' requirements. Mr. Kalivianaks stated that Ceco had ~' performed certain analyses already on the bulk of the isolation valves; ' which bears on the NRC staff concerns. This. data was forwarded to the -NRC' by letter dated October 9, .1990. At the present time, the NRC staff' - 'will-not-pursue the issuelof accelerated velve penetration testing, . pursuant to the licensee's:QA Program commitment to Regulatory > . , Guide.l.33 and associated enforcement actions will be reconsidered in ' - connection-with NRC-staff-review of testing'done during the upcoming
- Unit'1c outage in the fall of 1990 and the' unit 2< outage in 1991. The NRC
1 staff also reiterated an, invitation < extended at the meeting for the E licensee to present information on public health-and safety protection. .l - limits..(e.g. ,10 ~CFR Part 100),:if :it was felt that the current ~~ >contain' ment performance requirements were-overly conservative. , 3. LJc_ensee Actions ,on: Previously ' Identified Items - lA.. (Closed) Violation'(254/89024-04;~265/89024-04): Failure to consider all safety functions of a valve in performance of the (, ; L10 CFR 50.59 safety, evaluation and failure:to perform a safety ,
evaluation when changing the material used in-a component. The licensee produced ~ copies of modifications M4-1(2)-74-15,.which a . initially added the "0-Rings" to the containment 11 solation' feedwater > "_. check valves, an'dM4-~1(2)-76-51, which replaced the original Viton
- 0-Rings with Kalrez ones. The' inspector reviewed the scfety-
evaluations for those modifications and found.them.to be . . ' acceptable. The licensee also' agreed to perform a safety evaluation , ' " lfor the change to the Parker compound. The . inspector has no further; ,
1 , 4 3 ,
, ,- . . , - 1 concerns regarding the material of the feedwater 0-rings, and this , , item is considered closed. BL (Closed) Unresolved item (254/89024-03; 3265/89024-03): Main Steam Isolation Valve (MSIV) leakage totals included in the Type B and C total leakage limit. Based on the information presented in the licensee's response, this item is considered closed. C.. (Closed) Unresolved Item (254/89024-05; 265/89025-05): Need to provide provisions to Type B test flanges on the Drywell and Torus: Purge Supply and Exhaust Lines. This will be tracked as an open ! item (254/90019-01;265/90019-01) to ensure that a modification is installed prior to the licensee terminating the accelerated Typo A schedule. D. (Closed) Unresolved Item (254/89024-06; 265/89024-06): Lack of , . guidance in licensee procedures in regard to minimum pathway leakage- , calculations especially for four and six valve penetrations.- , .' Several discussions were held between the licensee and the ' inspectors as to'how the minimum pathway leakage should be . s , .. calculated.for multiple valve. penetrations. .The inspectors agreed i f, that the revisions being made to the corporate directive would v ' resolve the-concerns of the unresolved. item, once the revisions were incorporated into the licensee's procedures. Review of R' actor Containment Building Integrated Leak Rate Test- Report- 4. e for Unit 2-(90713) The' inspectors reviewed the." Reactor Containment Building Integrated Leak- ' Rate Test,1 Quad Cities Nuclear. Power Stationi Unit 2 April 27-28, 1990" '
- report submitted by. the licens'ee on July 26, 1990. The inspectors noted
- two minor errors..in the report and_the report cover letter. First the ! Ecoverrietter stated that the. test was witnessed by Region Ill inspectors. Although the inspectors were onsite.and intended to witness - the test, the final site exit was April-26, 199_0,.which was before -. pressurization-began. 'Second,Ethe test _ log (page 16)Lnoted that,the (prime computer. failed during :the Type At test,:and :that data was ' collected manually. ' However, this was not discussed in section A.3 '" Type A Test . . ,. 1 Measurement"-(page 9) which= stated that the test was performed-using a ! cdirect. interface between the data acquisition system and the prime' ( .omputer. = This error-was discussed with the licensee who noted that the data was manually entered into the prime computer for a portion of- the ,: Type A' test-(the last 6 data points). The DAS-to-prime connection was . regained prior to! start of the verification phase. Neither of these , errorsthad any impact on the. test results, and are included here only. for the sake:offcorrectness. 7 o
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Tae . inspectors independently calcuiated the as-left leak rate using. 1 a . iicensee-supplied dr There was good agreement (to the 1 third ~ decimal place)y air masses. between the inspectors calculated results and-the. 'l g l q. ? 4
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- . . . . . . . . licensee.'s.1The inspectors also calculated and- compared the verification - test'resu'lts:as well as'the' penalty.' additions for non-vented penetrations. t - The as-left value was 0~51 wt%/ day, or two thirds of-the allowable: . . .*: -leakage -limit (0.75 wt%/ day. ) After adding the correctionsidue to- - O pre-test. repairs. and adjustments to the containment boundary, the- + % g containmentjagain failed irf the as-found: condition.- A detailed review'of '_failing penetrations was' described in Inspection Reports = . , -No.:50-254/89024(DRS);No.'50-265/89024(DRS),andwasthesubjectofthe bl' , C . September 25, 1990 meetingLdescribed above.- t Ii r k [I , _ , ' P 3 m o,m . e ._ ' r - r! e t - .. - %l y. ! s s' ' s y ? ' y h'jijl i;.; < , 3
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_ , . QUAD CITIES UNIT 1 VALVE FAILURE HISTORY Year of Test yglyg '4 76 77 79 80 82 84 86 87 89 MSIV A Inboard X X MSIV A outboard X X X X MSIV B Inboard X X X X MSIV B Outboard X X X X X MSIV C Inboard X X X X MSIV C Outboard X X X X 'MSIV D Inboard X X MSIV D Outboard X X X Feedwater A In X + + + + Check A out X + + + Valves B In X. X + + + X + + B Out X X X + + + X + 'Hain Steam Drain X + + X + Drywell Exhaust X X X X HPCI Steam Exhaust X X + + + X Drywell Floor. Drain X X X ACAD In Drywell X X Drywell Head Access -X X X X Hatch 'Drywell Head-Flange X + ' + 0xygen' Analyzer Drywell'Eaulo Drain + . Max path totals (%La): 4.3 7.0 2.8 8.8 1.6 4.5 2.9 7 .' 3 1.6 5.7 Min path totals (%La): 1.9 1.0 0.2 3.9 0.4 4.3 2.4 2.6 1.0 5.4 Acceptance-criterias, Max path: total leakage < 0.6 La . Min path total leakage < 0.75La ' Leakage' marked. as "+ ' indicates penetrations where. the licensee could not determine the act dal leakage. Total values for those years ~are -the: minimum leakages; actual values would have been much greater. l l .
my_ .-, .
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,. gpAQ CITIELURIT 2..VALVI FAILURE HISTORY y m f-Test Valve 74 76 78 80 81 83 85 86 88 90 MsIV A Inboard X X X MsIV A outboard X X X X X X MSIV B Inboard X X X MSIV 3 Outboard X X X - MSIV C Inboard X X L X MSIV C Outboard X MSIV D Inboard X X MSIV D Outboard X X X reedwater A In X + X X X X X + - Check A Out X X + + X X X + Valves B In X X + + X X B Out X X + + X X X X X . X X ' ' Main 8 team Drain - X X X RHR8 Suppression Chamber Spray B .. Drywell Purge X + X X X X A HPCI Steam Xxhaust X X X X X Drywell Floor Drain ACAD In Drywell + X X _ + Drywell Head Flange TIP Purge Check Valve + oxygen ':nalyaer +
8ervice Air X RBCCW Return Max path totale (%La): 6.6 4.8 11.2 0.9 8.8 2.4 6.7 1.3 3.5 8.2 ' 5 Min path totals (%La): 2.1 2.5 3.8 0.5 0.7 0.4 1.0 1.2 3.3 4.5 i - Acceptance criteria: Max path total leakage < 0.6 La Min paths total leakage < 0.75La _ leakage marked as "+" indicates penetrations where the licensee could rit determine the actual leakage. Total values for those years are _ tha pinimum leakages; actual values would have been much greater. - , Penetrations marked as "*" were not tested for either unit prior to the 1990 Unit'2 outage. Leakage for prior years is unknown. _ e M ' ' = - - - = . ...i...---- ,
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. , . , QUAD CITIES /NRC MEETING l l l RESPONSE TO NOTICE OF VIO ATION l DATED 8-17-90 l l SEPTEMBER 25,1990 l 1
- __ -_ __ - - - - _- i . . ' i , QUAD CITIES /NRC MEETING ! AGENDA '
l ! . INTRODUCTION N. KALIVIANAKIS i
- RESPONSE OVERVIEW
R. BAX , l '
- FEEDWATER CHECK VALVES
. - TEST METHODOLOGY R. BAX , - WATER TEST REQUEST J. GLOVER - FEEDWATER MODIFICATION ALTERNATIVE C. MOERKE L
- HPCI CHECK VALVE
C. MOERKE
- PREDICTIVE / PREVENTATIVE
MAINTENANCE PROGRAM R.ROBEY
- CONCLUSIONS
N. KALIVIANAKIS September 25,1990 - ! l - . . . . . . . . . . . .. . . .. . . . . . , _ _ _
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, _ QUAD CITIES /NRC MEETING 1 - INTRODUCTION Purpose e -Resolve the NRC's concerns with CECO's response to the Notice of Violation _
CECO concurs with the violation in that a timely resolution of poor valve performance during testing has not always been achieved The discussion of the meeting will focus on a NRC's concerns with our violation response
- Progress towards the resolution of i repetitive failures - Update of our investigationa to resolve the leakage pathway concerns Feedwater Check Valves e _ HPCI Steam Exhaust Check Valve e - - Timeliness of the development of the . Predictive / Preventative Maintenance Programs l r .-- -
__ - ei 's ? QUAD CITIES /NRC MEETING ' ! BACKGROUND l I inspection Report 89024 delineated e l several containment valves / penetrations
which have experienced repetitive failures , ' during Local Leak Rate Testing (LLRT) ' ' Main Steam Isolation Valves s l- Improvements to maintenance techniques - , in 1986, Quad Cities Mechanical e Maintenance Department acquired special ' , l lapping tool which provides a more uniform - seating surface ' Air operators are rebuilt every other e Refueling Outage Testing technique has been enhanced - 3 of 4 valves are closed with steam flow a Valves are tested while the steam lines
+ are warm ' - Since the implementation of these actions, test performance has significintly improved . . -. .. -
_____ . ____ _ .
. . , ! QUAD CITIES /NRC MEETING i i BACKGROUND
1 , Main Steam Line Drain Valves a . 900 pound class Crane gate valves were - replaced with 1500 pound class Anchor Darling split wedge gate valves l- Acceptable performance has been - demonstrated on both units during the , previous outage Reactor Water Cleanup Suction Valves L = 1201-5 valves on both units have been - replaced with Anchor Darling split wedge gate valves > - Plans to replace 1201-2 valves were deferred so that the concerns identified ' during NRC sponsored MOV testing and poor performance during LLRT can be resolved simultaneously L Effectiveness of valve 1201-5 replacement + - l will be demonstrated during upcoming outages l I @ ,- -w-e- w w ,ww-,,-w--_w,- w . , - - , , - - , - _____ _ . _ _.__ _ _ _ . -
_ _ _ _ _ _ _ -__ _ _ _ - --
. ' QUAD CITIES /NRC MEETING l BACKGROUND Drywell/ Torus Purge System
e , In the past, valves were replaced when they
- failed during testing The Station identified a failure pattern of - i l valves and developed a preventative ' maintenance program . Valves which have not been previously replaced will be changed out in the ( upcoming Unit's Refueling Outages I -
- Valves will then be replaced after three
operating cycles regardless of test performance Drywell Floor Drain Sump Isolation Valves e - Gate valves will be replaced with plug valves during upcoming unit outages . L
- Plug valves have been successfully used
at Byron and Braidwood Stations - Effectiveness of replacement will be I demonstrated in subsequent outages 1 1 a. . . .a. - - --. -. .
_ _ . - _. _ _ _ _ _ _ ___ _ . i i g - , , . QUAD CITIES /NRC MEETING
BACKGROUND 1 I The NRC Staff accepted the corrective = actions and the implementation schedule for the items which were previously l discussed l The NRC Staff's concerns focussed on = the actions and implementation schedule for , - Feedwater Check Valve
, - HPCI Exhaust Check Valve - Development of the Predictive / Preventative Maintenance Program , , 7 b - . . , . . . - - _ _ - . - . . _ - . , , _ , _ , . _ , _ . , , , _ . , , , _ . _ , _ , , _ . . _ , , , _ , _ , , , , , _ _ _ _ _ _ _ _ , _ _ , , , . , , _ , _ _ . , _ , _ _ . , , , , , , _ , , , , , , . , _ _ _ . .
- . ' , FEEDWATER CHECK VALVES OVERVIEW = CECO Response Various maintenance techniques have been - applied to resolve the repetitive failures - Most recently, Quad Cities has applied maintenance techniques on the valves which have been successful at Dresden and LaSalle Stations - Additional Actions Proposed Due to the concerns identifed with the test a methodology, additional drain lines will be installed to prepare the volume for testing if the valves fall, CECO would submit a e report describing the corrective actions which will be implemented to Region ill within 90 days after the completion of the outage = Since the issuance of the response, CECO has identified that other plants have received NRC concurrence such that tests are not required on the feedwater check valves for air through leakage -_ -__-__ ___ __- _ _ _ _ _ _ _ _ _ _ - _ _ _ - _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
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I., -
- c . _ FEEDWATER CHECK VALVES
l TESTING METHODOLOGY 1 I The testing methodology of the valves is = suspect based on the results of the investigation performed on the Unit 2 valve failures i - Valve leakage during as found LLRT could not be quantified , - Visual inspection revealed tight clearance of the trim-to-body and disk-to-seat - Shop testing of valves which failed was L conducted and revealed essentially 0 sofh seat to disk leakage Concerns with present testing method L
= 18' volume is drained through one 3/4" - drain line e - Air pressure is applied to assist in ' draining the volume thereby ' cracking' open the valves I - During pressurization for testing, it is questionable if sufficient force is available to close the' ' cracked * open valves , , l l - .-- - . - . - - . . - - . .. -_ . - - _ _ _ _ ,
. . . . - , .- A . ,. m - d' - . . , , MSIV ROOM f6 J ! DRYWELL NEW
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. " EXISTING VENT ___ ._I , ' EXISTING ) VENT - ! GT '3 ~ ~ ~~ ~~ [ ,/ /
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FLOWL ,- - ( 4W 'l i t * v . A t_Lt_ = 3 .. C 3 ' EXISTING ,( DRAIN NEW /43 = DRAINS QUAD CITIES FEEDWATER CONTAINMENT ISOLATION CHECK VALVES __ - - - - . _ _ __ W
- - - . . - . - - - , , . . , , ,, , ,. . . _ FEEDWATER CHECK VALVE TESTING METHODOLOGY Conclusion a Valve is not properly seated during testing - due to the method utilized for draining - Improved testing methodology will be implemented during upcoming outage Additional drain lines will be installed e to provide for better volume preparation The valve will be seated with water and e air pressure ' - Expectation is that the valve will pass the as found leakage test
- Additional valve improvements will be
implemented on "A" loop during upcoming- Unit 1 Outage
" ' ' - - -' -- . - _ _ _ . . . _ . _ _ _ , _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ ' _ _
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FEEDWATER CHECK VALVE l REQUEST FOR WATER TEST , Since the issuance of the response, CECO a ! has identified that Plant Hatch and ' Susquehanna do not test the feedwater check valves for air through leakage L - Plant Hatch l
- Received NRC approval to perform water
l tests in place of air- tests on 6-20-89 . 1 - Susquehanna !
- Received NRC approval that existence of
a water seal would eliminate feedwater check valve through leakage on 7-31-85
- Appendix J tosting was continued due to
the potential stem and packing leakage; however, the Appendix J combined . leakage A formal submittal to justify water testing = will be prepared and submitted to the NRC for review and approval - A Technical Specification amendment or FSAR revision will not be required When approved, the water testing of check a valves would be added to the IST Program i with defined acceptance criteria , ..-.,-,,,,.w , -#w,,,_---, - . _ , . _ _ _ _ _ _ , , -
. o , FEEDWATER CHECK VALVES REQUEST FOR WATER TEST The Feedwater Check Valves do not clearly = meet the criteria defined in Appendix J - They de not provide a direct connection between the inside and outside atmospheres of primary containment - The lines would be water filled during post accident conditions Basis for Water Testing a - The feedwater line from vessel to the inboard check valve holds approximately 100 cubic feet of water - During normal operation, the line is filled with 340 degree F water at 1200 pala - Post LOCA depressurization would result in feedwater line blowdown - Containment atmosphere release does not occur until the water is gone
- - Preliminary calculations demonstrate that
sufficient water remains in the line following blowdown _ _ _ _ _ _ _ __ _ _ _
. , . . , FEEDWATER CHECK VALVES REQUEST FOR WATER TEST . Basis for Water Testing (continued) - The feedwater line inside of the drywell is safety-related, seismic piping therefore pipe break is not a concern - The only credible manner that the remaining water can be lost from the feedwater line la for the water to be pushed back out of containment by high containment pressure through leaks in the feedwater check valve - Water leakage rate testing will therefore be performed on the two valves in series at a delta P = Pa Upper bound of this leakage rate can be e measured through testing - The maximum leakage rate will be defined as the amount of water calculated to remain in the line divided by the amount of time isolation is required
_ _ _ _ _ _ _ _ _ __ . ,: . . . . - . . t FEEDWATER CHECK VALVES i REQUEST FOR WATER TEST , Proposed Request for Water Test a , .I Credit would be taken for water left in the - ' line after blowdown IST water test would be performed in place l - of an Appendix J air test The 15' loop seal upstream of the outboard - check valve will be credited
- Provides a leak tight barrier against
leakage from containment when pressure is less that 6 psig The outboard piping is currently non-safety
- related , ' l
- Piping will be analyzed and upgraded to
categorize the piping as safety-related, i seismic piping - FSAR Design Basis LOCA Curves demonstrate that after approximately 2.4 days, the l containment pressure is less than 6 psig
- Leakage does not occur due to the
presence of a water loop seal , . 84WF - - - - - . . . . - . _______.___,,,.._-.e.._.,,_m..,m.y...-.__. - - ., .,,,,_,. ,.e,m., ..---..-.,_y,, _ , . , . . . r ...n.,. -_.-
i
I t
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I i FROM FEEDWATER ! HEATERS t t i ' i l MO-1-32OSA MO-1-32O5B /4 ! - - 1 , . i 4 ? i ! ' - 15.2* l 1-220-59B
l I ! /\\
1 , ! >' 1 1-220-59A . I TO t A g RCIC l 1-220-62A \\ g g TO.HPCI 1 i . .. TO 4 - CLEAN- ! , UP 1-220-62B ! X-9B - v . ! X-9A ' - i 1 i ! FEEDWATER PIPING OUTSIDE THE DRYWELL' . .-
- l ! ! '
.. !. . .- . . - -
_ . _ _ _ ___ . . _ _ _ _ _ _ _ _ _ _______- .. _ _ __y
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' ' ' - .: . l FEEDWATER CHECK VALVE 4 l REQUEST FOR WATER TEST Proposed Request for Water Test (continued) ' s Acceptance criteria for the water test will - ensure that the water inventory in the line i remains for a minimum of 2.4 days at '
a 48 psi pressure differential
1 \\ Other Features I = - Check valve upstream of the outboard check valve is included in the IST Program and subject to water testing
- The check valve will contribute in
restricting back leakage through the feedwater line l - MOV 3205- A/B are also water tested L Manual actuation of these valves would i e I further restrict back leakage l 1 , f - - -.--e,-_, a - --- . --++ . - - - -, -- , -w-+w-i------r ye a- --w t~- -s-r- - + - -- - .
. _ _ - . - - - - - - - .- - - _-. _ - . - - . . , . , FEEDWATER CHECK VALVES REQUEST FOR WATER TEST
a Conclusion Based on the NRC's approval of water ' - testing at other plants, CECO is developing ' similar technical Justification to remove the feedwater check valves from the ~, Appendix J Program Our intention is to pursue this submittal - , in parallel to the improved testing '
methodology , i n- , -- - . - - - - . - - . . - - - - . - - - - - - - - - - . . . - . - - - . . - - - - . - - - - . . - - - - - - . . - - - - - . - - - - -
- _ _ _ _ _ . _ _ _ - _ _ _ \\- . . ,- FEEDWATER CHECK VALVES i l ALTERNATIVE SOLUTION l ' i As discussed previously, CECO is pursuing e - Enhancements to test methodology - Request to remove the valves from the ' Appendix J Program , in our response, CECO committed to provide e the NRC an action plan on the valves within , 90 days following startup in the event that the valves fall - The intent of the report was to provide Region Ill with a specific action plan on the feedwater check valves to effectively communicate our commitment - The report would address the actions taken and future plans for modification to address the valve failures CECO is reviewing the feasibility of l = replacing the valves as a contingency to the previously discussed options , gb( coe&d I j . . .. - - . - .
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l I i i i I I ' i l l N I - - !l . HvAc rucT / ' i'/ w ?? JL F E EDWATER LIN E S P' L A N N F cowruits . HVAC PUC . fs ' i: .. /, , y , e- 1 T' q .....m. - e.,. y 1l, m.w .tuu , 3 -'+ .9 _ . _ . . . w 3 o [GR ATING , k.' TY PiC AL B E CTION (INSIDE PKY WE LL) GUAD CITI ES P E EDWATB A CO NTALHMENT ISC L ATION CHECK VALVES
. . . . .. . FEEDWATER CHECK VALVES ALTERNATIVE SOLUTIONS J Replacement of these valves may be difficult e due to space restrictions i Estimated cost to replace the valves is e 2.2 million dollars for both units
I Estimated radiation dose to complete the e replacement of both units is 180 REMS ' Based on vendor delivery dates, the earliest l = . L the replacement can be accomplished - Unit 1 Spring,1992 Refueling Outage . - Unit 2 Fall,1991 Refueling Outage l Conclusion a CECO is confident that the enhancements to - the test methodology will be effective . CECO will aggressively pursue NRR's approval - ' to conduct the water test on the feedwater check valves - The valve replacement is being considered as a contingency option to the above actions . .' l _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ . . _ . . _ , , _ _ _ . . _ . _ . . . , , . _ . . . , _ . _ _ . . . . . . _ , , _ _ _ _ , . . . . . _ - , _ _ _ _ _ . _ _ , _ . _ _ . _ _
. _ - . - - - _ _ - _ _ . - - . - - - -. -- -- ,. - o . . , , . HPCI STEAM EXHAUST CHECK VALVE OVERVIEW . Background e - Corrective measures to address the failure ' of the HPCI check valve have been unsuccessful - , l - The cause of the failure is believed to be ' due to the design and the performance of ' L monthly surveillance testing
- Insufficient steam pressure which causes
- the valve to cycle and a * chugging" ' phenomena which occurs in the exhaust line damages the valve seat l '
- Valve design is inappropriate for the valve
l orientation a CECO Response - Improve surveillance testing by restricting the period of low speed turbine operation - Investigate the need for spargers . - Investigate the feasibility of reorientating L the valve - Perform LLRT of the valve at 9 month interval I a------
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L . HPCI STEAM EXHAUST CHECK VALVE i OVERVIEW ' . During the 9-13-90 meeting, the NRC i e communicated their concern that CECO is , not implementing a known resolution to the problem CECO continued to investigate potential a l alternatives following the issuance of the
response b - CECO has identified a modification which l would eliminate the need to test the HPCI ' exhaust check valve . - The modification was briefly discussed with the NRC Staff on 9-13-90 CECO will modify the existing configuration m such that Appendix J testing of the HPCI Exhaust Check Valve is not required l l - - - - - - - - - - -
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SKETCH i
., _ 12'- O * ~- (REF) , TO TORUS T ' f (+), s viJ i ( l / 24"x 12" RE D. 1(2)-2301-74 ' (STOP CHECK) 1(2)-2301-45 1 (DVO CHECK) 1(2)2306-24' ' l l- ? ] I J l UNfT 1 ONLY ' -FROM HPCI TURBINE ' o l l EXISTING CONFIGURATION ELEVATION , i 1 -.., -..-=,,,-.,,w.-- .-,,--.,-..=~,,,5. ,,w,,y,,---,,w , - - , +
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, _ _ _ _ - _ _ _ _ _ _ - . . ~ '. ,. . p -- - - --- T + TO CONT ROL ROOM ' i 1 1 to Ld9 __ D.H}--(MN M BLOCK VALVE =E .- T 2301-5- Md % _. s __. {{ 2301-74 44 _ 2301-6- 7 I T ' _- _ ~ - - - - REMOVED
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' 's LINE / SUPPRESSON C HAMBER , - - - - - - _ _ - - _ - - - _ - - _ - - _ _ . - _ . _ _ _ _ . . _ _ - _ _ - _ _ _ _ _ - - _ _ . _ _ _ _ _ _ _ _ _ _ _ _ _ _ . _ _ . . - - . _ _ - - - _ _ - _ - - - _ _ _ - _ _ _ . _ _ _ _ - - - _ - - - - - -
r , 'I . -
I . l HPCI STEAM EXHAUST CHECK VALVE ' MODIFICATION <
. Proposed Modification . . Install a new 2* diameter line from the ' - Torus to the turbine exhaust line downstream of the 2301-74 valve Benefits e The modification would eliminate the need - ! to perform Appendix J testing on the HPCI Exhaust Check Valve 4 Improved containment isolation performance " - would be ' achieved The proposed modification is estimated to cost = 1.8 million dollars The modification will be installed L = - Unit 2 Fall,1991 Refueling Outage - - Unit 1 Spring,1992 Refualing Outage l (- . - - - - - - - - - - . - - - -_.
. - . , . i HPCI STEAM EXHAUST CHECK VALVE i MODIFICATION
) Conclusion e - The implementation of the modification will resolve the leakage pathway concerns of the HPCI Exhaust Check Valve
- Configuration has been effective at
other plants , (
- NRC concurrence will be requested
Interim Actions e - Existing valves have (will) been upgraded with more resilient seats to better withstand t i effects of cycling and ' chugging" - Surveillance testing has been revised to restrict low speed operation of turbine - Testing will continue at 9 month intervals - Effectiveness of these actions will be l demonstrated during futurf 'esting
- Test interval will be re-evaluated based
on test results 1 . -- - -- - - _ _ _ _ _ _ , _ _ , ,,,,~,,,,,m-,-- , , - - - ,,w,- >-----m--- n.,,..-w.- - , + , , , , ., -- ,avp w- -.v- - -
- - _ . .. _ _ . . . . PREDICTIVE / PREVENTATIVE MAINTENANCE PROGRAM = CECO Response A predictive / preventative maintenance program - will be developed based on a historic review of maintenance and test history for all (159) containment valves ' The program will be developed by June,1991 - and implemented during the Unit 2 Fall,1991 Outage a NRC Concern Development schedule is not aggressive CECO Program a - The purpose of the program is to maintain performance not to address existing repetitive failures - implementation of this program is an- . enhancement to the. existing program- to assure any future repetitive failures- are identified and- addressed- in a. timely and effective manner ,_y - - . . . . . . . . , , . - . - . - _
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PREDICTIVE / PREVENTATIVE L MAINTENANCE PROGRAM l Program development consists of the = following elements:
- Compile and correlate work history for 159 L containment isolation valves - Identify any trends from test results and evaluate trends for failure patterns - Correlate test failures and maintenance i history - Use maximum pathway leak rete limit for each containment valve ' ' Formalize Program = - Revise / develop procedures- - Review. and approve program
~ - Provide training to appropriate personnel l Resources for program development is e ' ' estimated at 3440 man-hours l l l < - - - - - , - - - - . , --
f. . . ~ - - PREDICTIVE / PREVENTATIVE MAINTENANCE PROGRAM a Conclusion Long term enhancement to ensure that - I the Appendix J test program is effective .in assuring leak tight system
- Programmatic and proactive approach
' to ensure acceptable- performana is , maintained
- Can' potentially predict valve failures and
l , readily identify. repetitive failures , ' Based on. the resource estimates, June,1991 - - development target date is realistic '
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- - . . . . . . , . ,. :e * , QUAD CITIES /NRC MEETING CONCLUSION = Feedwater Check Valves ! CECO is confident that improvements to - test methodology will be effective .
- Installation of drain lines to prepare
volume for testing and use of water and air to seat the valves CECO will request NRR's approval to perform - - water . test (in lieu of air test) on the feedwater check valves Replacement- of -valves is being evaluated as -- a contingency HPCI Steam Exhaust Check Valve a - System will be. modified to eliminate the need to test the HPCI Exhaust Check Valve Predictive / Preventative Maintenance Program is a a long. term enhancement to maintain good- valve performance- . , -- _ _ _ . . , . . , , , , , , , , - , , , . . . , , , , , , - , , - , , , . , . _ . . . - , , - - - - - - - , ,, ____ , , , , , - , , - _ }}