IR 05000295/1990014
| ML20028G808 | |
| Person / Time | |
|---|---|
| Site: | Zion File:ZionSolutions icon.png |
| Issue date: | 08/21/1990 |
| From: | Danielson D, Jeffrey Jacobson, James Smith NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | |
| Shared Package | |
| ML20028G804 | List: |
| References | |
| 50-295-90-14, 50-304-90-16, IEB-85-003, IEB-85-3, NUDOCS 9009050024 | |
| Download: ML20028G808 (44) | |
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, i U.S. tlUCLEAR REGULATORY' COMMISSION - ' REGION 111 x ' Reports No. 50-295/90014(DRS);~ No. 50-304/90016(DRS) - Docket flo. 50-295; 50-304 Licenses No. DPR-39;-No. DPR-48 Licensee: Commonwealth Edison Company Opus West 111 - 140.0 Opus Place Downers Grove, IL 60515 Facility Name: Zion Station, Units 1 and 2 Inspection At: Zion Site, Zion, il Inspection Conducted: June 19-22, 28, 29 and August 17, 1990 Inspectors: MI(s%k h 8/$//90 J. F. Smith Date &km b E' 96 ~ . d. M. Jacobson-Date ' Approved By: od74/ b M 8/2//ho D. H. Danielson, Chief Date Materials & Processes Section Inspection Summary Inspection on June 19-22, 28, 29, and August 17, 1990 (Reports No. 50-295/90014(DRS); No. 50-304/90016(DRS)) Areas Inspected: Special inspection to followup on findings of the DET in the area of MOVs (73756).
Results: Five unresolved items are identified in paragraphs 2.a. through 2.e.
As a result of the inspection, the following observations have been made: The licensee has indicated a weakness in the area of control of design information (torque switch settings).
The licensee has indicated a weakness in the area of prompt corrective action.
/ The licensee has demonstrated a strength in findin9 ways to perform full
differential pressure testing of all IE Bulletin 85-03 valves.
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LPersons Contacted: , ! Commonwealth ~EdisonCompany'(Ceco)' ~ ' < ,
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- T, J. Maiman, Vice President 4!
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- K.' L. Grasser, General Manager.
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- G. P.fWagner,. Nuclear Engineering Man'ager
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'**T. P. Joyce, Station Manager; . .. ., p
- F. G. Lentine,; Design Superintendenti
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K, f *R.. Chrzanowski, Licensing Administrators
- P. F. Cantwell, Assistant Technical Staff-Supervisor
P . L..J. Laspisap Assistant _ Technical Staff'Superv.isor' '
- E, L. Robey, IST Coordinator.
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- L. B. Cerda, M0V Coordinator.
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- W.f Stone, Regulatory Assurance
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- P.1 J. ' Pawlak,' Technical' Staff Engineer:
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- B. Rybak, N.E.D. Design Engineer m
e R.-Branson,'N.E.D. Design Engineer
- T. VanDeVoort,' NQP Superintendent l
- S. Szumski. N.E.D. ' Power Systems Engineer.
! . K...Henderson,: Technical: Staff Engineer L ' '
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- D.; Taylor', Nuclear Licensing
' E U.- S. Nuclear Regulatory Commission -('NRC) , m, _ H.TJ. Miller, Director, Division of Reactor Safety
. , '*T. O. Martin, Deputy Director, Division ofEReactor Safety
- H. A' Ring, Chief,' Engineering Branch, DRS'
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- J._M. Jacobson, Metallurgist, DRS
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. , .; '*C.-P.- Patel, Project Manager, NRR ' 'M, '*J._D.-Smith, SRI,' Zion
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t 9- '*T.--G; Scarbrough, Senior Engineer, NRR-
- N.' Wagner, Reactor. Engineer, NRR
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- W. A. Slover, Reactor Inspector, DRS
- J.,F. Smith, Reactor inspector, DRS
- J. F. Wechselberger, Project Director, NRR 4'
s - F. J. Jablonski, Chief, Maintenance and Outages Section
.
- Denotes those participating in the management meeting in Glen Ellyn,
- lllinois, on July 25,'1990, i
, . %m Denotes those participating in the preliminary exit interview on i June 29, 1990.. m
- Denotes those participating in the telephone exit interview on
" , August 17, 1990.
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IE Bulletin 85-03: Commun Mode Failures Due to Improper Setting of Switches in Motor Opera ted Valves This inspection was initiated as a followup to the Diagnostic Evaluation Team findings in the crea of motor operated valves.
The NRC regional inspectors joined the DET during portions of the last two of the three weeks that the DET spent at the Zion site.
The inspectors received the more significant informat.an f ound by the DET directly f rom the personnel involved.
This method optimized communication by permitting immediate clarification of questionable areas, liowever, the assembled detoils of the DET inspection were not availdble at the time of this report, so it
would be premature to attempt to draw any final conclusions regarding - these findings at this tine.
The following items appear to summarize the more significant problems identified in the aree of motor operated valves, . o.
Torque Switch Setting Original torque switch setting values were provided by the orchitect-engineer, Surgent & Lundy (S&L).
Records of these settings and Chdnges to them were maintained by the Electrical Maintenance Department.
The S&L settings are the ones originally used on the volves.
Any changes to these settings were permitted only after approval by a Technicol Staff engineer.
This process was sometimes performed by telephone. There was no record of engineering evaluation and no engineering record of the new torque switch setting volue.
The only ecord of the chonge wos in the Electricol Maintenonce Department MOV r history record where the number was changed.
As changes were made, the originol S&L list became less representotive of the octuol field settings.
With the odvent of IE Bulletin (IEB) 85-03, it became necessary to test the operation of MOVs at the full rated differentiel pressure ond to identify the torque switch setting.
The licensee relied on
Limitorque end the valve manufdcturers to provide calculdted torque switch settings.
This was the same calculation provided originally by S& L. Zion's opprooch to IEB 85-03 was materially different from that of neost other licensees.
Instead of relying on calculations ond MOV enalysis to provide confidence thot the MOVs would operate at the required differentiel pressure, Zion tested thelin at full - differential pressure.
By directly testing the MOVs in th ' menner prescribed by IED 85-03, Zion ovoided the need to perform o. alysis of MOVs.
Very few other stations were oble to oc this.
The Zion tests incluced no ossumptions, onelyses, colculations or conservative estimates os other plants did and still do.
They simply demonstreted thot the volves operated at the specified differential pressure with - the switch settings on them at thot time.
T h is opproach was conciendable insofor os IED 85-03 was concerned, but disodventoge to Zion becduse it deferred 3ubsequently proved to be o the time when the licensee was obligoted to begin using motor operated vo lve ano lysis sys tems.
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, . -. The listing of. torque switch settings provided in the licensee's response to IEB 85-03 provided a second record of the torque switch' . settings. _When the licensee reviewed the Electrical Maintenance , ' records, a-third list was generated.
The performance of the full differential pressure test for IEB.85-03 provided compelling evidence of the operability of the valves in that program, provided the torque switches.in those valves'could be shown to be set at the-same settings as they were when tested.. Physical examination of the torque switch settings provided sufficient anomalous readings to vitiate confidence in the validity of the plent's records
- of torque switch settings; Pending completion of the review of information in this area, this is considered to be an Unresolved Item (295/90014-1;304/90016-1).
b.
Improper settig of ' Torque Switch Bypass (Failure to Follow Corporate Guidelines) The DET discovered that the licensee had set a significant number of torque switch bypass switches at considerably below the figure recommended by Corporate Headquarters. The figure recommended by the one year ol_d corporate guidelines is approximately 25% of the opening stroke. Some of the valves at Zion were set well below 10% of the opening stroke.
The NRC inspector confirmed the DET findings. The corporate recommendations of Ceco follow the consensus of the industry. When-the limit switch which controls the torque switch bypass is set at about.25% of the opening atroke, the amount of bypass provided conservatively blankets the needs of all nuclear power plant valves so that no individual valve analysis is required.
However, in the case of Zion, prompt compliance with the corporate guidance would have incurred serious problems in other areas.
The Zion Station MOVs are provided with both two rotor and four rotor limit switches. When using the four rotor switches, one set of open and ene set of closed switches are used for position indication lights. The remaining set is used for other purposes, such as torque switch bypass. When the M0V is equipped with only a two rotor limit switch, the torque switch bypass must share a limit switch with a position indicating light.
In such an arrangement, there is an inherent conflict. The position indicating light switch should not indicate that the valve is closed until the valve is, indeed, closed. The torque switch bypass, on the other hand, must continue to bypass the torque switch until the high torque required to disengage the disk from the seat is past.
As indicated by the corporate guidance this can be as much as 25% of the opening stroke.
Obviously, the same switch cannot be set at both 0% and 25% at the same time.
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.In the case of Zion Station,-the problem was:further compounded by.
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- the= original wiring provided for"the MOVs.
- In order to simplify;the J
' wiring, most two and.four. rotor limit: switches were wired the same; ' '
' way ,That -is,-.they were all wired as if-they were two rotor-limit
X switches. The licensee is aware of this problem and has initiated '
- 4 work-to correct it,: but cannot perform work.on the equipment when it'.
i issin' service.
Even removing,the cover from the M0V can initiate'an . actuation because wires in the M0V are n't all deactivated when the' ' ' o-power is cut to the M0V. Where two rotor switches must'be replaced,; I that work _is' complete or nearly complete.-
4 Until' the limit switches are completelyJconverted,to the four rotor - L wiring in the applications required, the licensee must continue'to; ' ,
defer complying with the corporate' directive on torque switch bypass settings, in the meantime, however,-the torque switch bypasses at Zion are set in accordance with an old procedure which' required:that fW they be set such that the-torque switch would be bypassed until.the ! i ' motor current dropped back to within 10% of its normalLlevel.
The4 NRC inspector reviewed each current trace lor the IEB 85-03 valves'in Unit 2 and confirmed thatlthe torque switch setting was beyond:the? " , point at wh_ich the high torque was necessary, t Review of the traces clarified some confusio'n voiced earlier by . _ . Electrical Maintenance personnel.
They had indicated that they.could s . -not always tell when the current came within 10% of normal and that " when that happened, they set the bypass at 5%. Some of the traces ' reviewed were of globe valves rather.than gate valves. After the , initial. current inrush, the current actually diminished below normal for a finite period. lIn these' cases, the pressure actually helped open the valve until the differential pressure dropped off with. increased flow. Setting the bypass at-5% would not jeopardize the.
opening of these valves.
The present procedure for setting torque switch bypass :-Procedure E022-2, " Repair and Maintenance of Limitorque Valve Operators," with ' procedure changes through May 24, 1990, now reflects the corporate guidance (25-35%bypassaftercurrentinrush).
However, this.
procedure does not require changing the bypass on valves previously set to other standards.
If such a change were implemented, the change in bypass switch position on an MOV wired for two rotor use could introduce problems in position indication and stroke timing.
Pending resolution of these and other problems, the improp(295/90014-2; er setting of torque switch bypass is considered an Unresolved Item 304/90016-2), u c.
NOV Position Indicating Lights Improperly Set The DET identified problems in MOV position indicating lights noting that some MOVs were at least 25% open when the lights on the control board indicated that they were closed. This condition gives rise to another problem in that normal stroke timing in the close < direction would only measure 75% of the active stroke time.
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4u 's 36; i ~ The'NRC_ inspector confirmed the questionableLcondition with-thei < ' t position indicating >1ights.- The problem is' recognized by(theilicensee and is related to the.one discussed in 2'.b., above. The' adjustment-of the torque' switch bypass' limit switch to actuate at the 25-35%' > open range is;normally acceptable, so.long as the rotor adjusted does ' . . not-also carry. the position-indicating ' light'.n :In' the instances noted above, the operator was still wired as a two rotor limit switch and- . introduced two problems. The first is that the light actuation.to- ~ ' indicate valve closure is displaced by;about 25%.. The:second is.that '
1 . the mispositioning of'the switch gives a false stroke time when using; the switch-to-light method of stroke timing. - P" Displacement of the close-indication by' 25% has little impact on - most properly operating systems.
Normally, when the close switch is momentarily connected, the circuit " seals-in" and the MOV fully closes and the early indication of the valve' closure goes unnoticed.. ' - ' However, if"the valve, fails to fully close, the operator:may be-given-a false " closed" indication. Additionally, on several: throttling valves, the seal-in feature is not-present.. This allows the reactor operator to adjust the disk position to regulate flow. When the reactor operator closes these valves, his only close indication is - the position indic.ating light.
On-several occasions, reactor' operators .left valves partly open because they released the close switch when the light indicated the valve'to be closed.
(At:thispoint,the valve was 25% open.) 'The licensee has provided an interim ~ a administrative' Corrective action in:this-area by instructing reactor.
- operators to hold the switch in the closed position for a specified
- time after the position indicating lights showed the-valve to be j closed.
Final correction cannot be achieved until the wiring of all j valve operators is converted to-the four rotor variety.
The effect of misplaced position indicating lights on stroke timihg
'is profound if the licensee attempts to. adhere to the~almost = universally used switch-to-light stroke timing method. However, there are several acceptable' alternative methods which the-licensee
- 7 may apply without serious drawbacks. The licensee is aware of all of-
-h them, but has not yet reached a decision on how'to handle'the problem.
Improp(erly set position indicating lights is considered an Unresolved . item 295/90014-3;304/90016-3).
d.. Previously-Identified !iOV Programmatic Deficiencies Were Not Corrected d
The DET pointed out that the licensee's SSF1 and an independent l contractor review had previously identified many of the problems i cited by the DET, but little or no corrective action was performed l .on them.
The NRC inspector confirmed the DET's observation.
Among the i problems with most potential significance was the contractor review of the volve IST program. This evaluation was given to the licensee ,i on July 12, 1989.
H 'ndicated that a significant number of valves which should have been included in the IST program were not. The valves are still not in the program and tre licensee has produced no
evidence to justify their omission from the program.
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, , ' n . . , ' o' In othe~ areas,?the: problems _withltorqu'e; switch setting, torque'- ' r y switch bypass. setting, position indicating light accuracy,l stroke-s timing l accuracy the need for. four rotor, limit l switches-and the' need to .. ' b rewire :some' f our rotor-limit switches. were all! previously.~ identified.
- , -to theslicensee. -The promptness of. corrective action.and the- . l . acceptability of theilicensee's scheduling ofothe: resolutions to the ~ < . . problems require realistic evaluation. This matter is; considered =an~-
UnresolvedItem(295/90014-4;'304/90016_-4).' ' , e Root.'Causes~of-Equipment Failures Were Not Always! !dentified m . e.1 p The.DET~noted that the licensee'did~not always.identifyithe root; sceu:e of-problems. As.an example, they cited inverted Service Water
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, Syst6m valves which have 'a history.of packing leaks and no root cause l determination.x , The NRC inspector briefly examined tnis area-and found a wide range- , s of value in the root causes established. -Although.someLroot causes-clearly defined the basis for the problem an'd madeieffective; - ~~ corrective action obvious,-there was a sufficient number of'
ambiguouscroot:causes to justify.a further study of_ root cause-i
- analysis. - This-is considered an Unresolved item (295/90014-5;-
< '304/90016-5).
- The NRC' inspector considered that evaluaticn of some of,the'less a
- definitive-root cause analyses by the Zion Human Performance - EvaluationiSystem (HPES) might~be appropriate and beneficial.
3.
Management Meeting-i As'a result' of the DET findings,~ a management meeting was held with' the S licensee in the Region III. office on, July 25,1990. The focus of the ' meeting was the operability 'of safety related motor operated _ valves - [ (MOVs) and the. Service Water System.
Specific concerns discussed were as .i follows: a.
Service Water System ' I (1) Pump capacity versus system resistance during-three pump operation with a single failure.
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(2) Lack of a flow " balance"'.of the system to assure that design , f flow is provided to all components.
(3) Reliability of MOVs in the system.
o < (4) Potential degradation of Component Cooling Water System heat.
I exchangers, due to fouling.
b.
Motor Operated Valves (1) Timeliness of torque and bypass swid inspections for non-IEB 85-03 scope valves.
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'I ' ' y" - "(2)JAdequacyfof fvalve test l program.
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. . . . . .. > ,: ..After1considering=the311censee's position in this: matter,(a decision was! ' by made to; perform aDfollow-'up inspection of;the' Service Water System and~ q
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C monitor thellicensee's progress'regarding MOV inspections.' Licensee.
. ?' handouts:for? thel" Zion Station Service Water /MOV~ Presentation,. ", .
- July; 25[ 1990'! are. enclosed with this inspection. report.-
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, 4,: Unresol'ved Items' ' ' - ' .. . . .. . .. - -. Unresolved, items are matters about which more~information is required.in; u . order'to ascertain whether they;are~ acceptable ^ items'or violations.
- Unresolved' items-are' discussed.in Paragraphs 2.a. through 2.e.
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W - 5.. Exit Meeting ' ' <
a d JTheNRCinspectorsmetwith!licenseerepresentatives(denotiedin ... > '
+, Paragraph 1) on August-17, 1990, to discuss;the scope-and, findings of:thec .m , inspect on. cTheLinspector also discussed theslikely; informational: ' '
content of'theninspection: report with regard'tol documents and processes ! . reviewed by the in.spectors during the inspection. - The~ licensee did note < > . identify any such= documents / processes as proprietary.
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i , , i . i ? 1. PUMP CAPACITY VS. SYSTEM FLOW DEMAND i i
2. DESIGN FLOW TO HEAT EXCHANGERS . , ) 3. RELIABILITY OF SERVICE WATER MOTOR
' i OPERATED VALVES
l- ! , \\- i i 4. SERVICE WATER SILTING
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PUMP CAPACITY - i , NUMBER OF AVAILABLE PUMPS
SYSTEM FLOW DEMAND - CONCLUSION l
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\\ SERVICE WATER PUMP PERFORMANCE DATA J _ ' A 1A 1B 1C 2A 2B 2C Pre Op 23430 gpm 23130 gpm 23330 gpm 21841 spm 21237spm 21667 gpm i Test e e o e e e I (1973) 158.2 h 153.6 ft 154.8 h 186 ft 193 ft 195 fi ) Opm Opm Opm Opm . @ @ @ - 314.8 ft 321.7 ft 319.4 h 321.0 ft - 3-Point 16000 gpm 12500 gpm 11500 gpm 11500 gpm 13000 gpm Test OOS . . . . . (6/90) 259.3 h 58. n 5. ft 60.8 h 251.1 h 16300 gpm 14500 gpm 15000 gpm 16000 gpm @ @ @ @ 224.7 ft 223.5 ft 222.3 h 230.8 ft _ High NOT 17m gpm 175N gpm im gpm Flow . N/A ~ OOS oost Test e e e (6/90) YET 204.9 6 204.9 n 204.9 ft
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_ _ . - - _. ,, s.-+ -. V' - % . .. 2B Service Water Pump Performance Tests Least Square Curve Fit 350 325 - -'- - "-- ^ - =i; - - - - 300 -
. .~. . 275 - " er i- - ' - . - p ~~ w - ,,%;;; . 250 -
- - - - - - + - g ~~~ . . 'A - i m 225 -' P - . 's 200 -- - -- - - -- - '. - - + - - + , - - - - ..
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) - SERVICE WATER PUMP PERFORMANCE
i ! o . PRE-OP PUMP CAPACITY
> i - DOCUMENTED AS HIGH AS 23,430 GPM > - DISCUSSION WITH PRE-OP TEST ENGINEER INDICATED EVEN HIGHER FLOWS WERE ACHIEVED BUT NOT DOCUMENTED
9
RECENT TESTING CONFIRMED , PERFORMANCE WITHIN 10% OF , ! PRE-OP CURVES l . -- - -. . . -. - . _ _ - - -. -
u- .. .\\ l ,. i - ! )- ! POSTULATED SCENARIO I '
1. BOTH UNITS ARE OPERATING AT FULL POWER 2. SERVICE WATER SYSTEM IS CROSS-TIED BETWEEN UNITS - . 3. ONE SERVICE WATER PUMP IS OUT-OF-SERVICE (5 PUMPS OPERABLE) 4. LOSS OF COOLANT ACCIDENT ON A UNIT 5. LOSS OF OFF-SITE POWER TO THE STATION ' 6. SINGLE FAILURE OF A DIESEL GENERATOR TO START l RESULTS: MOST SCENARIO COMBINATIONS - 4 PUMPS AVAILABLE SOME SCENARIO COMBINATIONS - 3 PUMPS AVAILABLE ESTIMATED PROB ABILITY OF OCCURRENCE: L ' 8E-12 PER YEAR (3 PUMPS AVAILABLE) ) i l -. . ... . -. . -- .. . _ _ _. _
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i POSTULATED SCENARIO 2 1. ONE UNITIS OPERATING AT FULL POWER AND ONE < UNITIS IN COLD SHUTDOWN 2. SERVICE WATER SYSTEM IS CROSS-TIED BETWEEN UNITS 3. TWO SERVICE WATER PUMPS ARE OUT-OF-SERVICE (4 PUMPS OPERABLE) 4. LOSS OF COOLANT ACCIDENT ON OPERATING UNIT I 5. LOSS OF OFF-SITE POWER TO THE STATION 6. SINGLE FAILURE OF A DIESEL OENERATOR TO START RESULTS: MOST SCENARIO COMBINATIONS - 3 PUMPS AVAILABLE SOME SCENARIO COMBINATIONS - 2 PUMPS AVAILABLE ESTIMATED PROBABILITY OF OCCURRENCE: 6E-13 PER YEAR (2 PUMPS AVAILABLE) )
. ._ . - . .' , ! n i \\ ! INITIAL SERVICE WATER FLOW DEMAND
FOR POSTULATED SCENARIO 1 ! (NO OPERATOR ACTIONS)
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. . COMPONENT FLOW (GPM) l DIESEL GENERATOR COOLERS 6,960 COMPONENT COOLING HEAT EXCHANGERS 21,200 ) REACTOR CONTAINMENT FAN COOLERS 22,000 . REMAINING FLOW DEMAND 3,150 l 53,310
- l l 3 AVAILABLE PUMPS WILL PROVIDE 53,310 GPM
TO MEET THE FLOW DEMAND OF THIS SCENARIO ' ) \\ i
.- . . _ _. .- - _ -. . . - . .-
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INITIAL SERVICE WATER FLOW DEMAND FOR POSTULATED SCENARIO 2 ! (NO OPERATOR ACTIONS) i i COMPONENT FLOW (GPM) l i \\ - DIESEL GENERATOR COOLERS 5,568 COMPONENT COOLING HEAT EXCHANGERS 21,200 ) REACTOR CONTAINMENT FAN COOLERS 11,000 ) REMAINING FLOW DEMAND 2,764 ' 40,532 I l l 2 AVAILABLE PUMPS WILL PROVIDE 40,532 GPM - TO MEET THE FLOW DEMAND OF THIS SCENARIO IN THE EVENT THAT FLOW EXCEEDS TH AT ESTIMATED - FOR THE COLD SHUTDOWN UNIT, THE OPERATOR COULD TAKE ACTION TO REDUCE FLOW DEMAND (i.e. ISOLATE RCFC'S IN EXCESS OF THOSE REQUIRED) ) i . - - - - - - . -_ - -
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- . CONCLUSION - I . I' AVAILABLE SERVICE WATER '
l PUMPS ARE CAPABLE OF L ) SUPPLYING THE REQUIRED SYSTEM FLO~W DEMAND . J ) , . - - - . . .. .. -. -. . -.... .. .. .. -.. - - _. -. -.
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DESIGN FLOW TO HEAT EXCHANGERS , j , .
i
ORIGINAL DESIGN CALCULATIONS - i i .I t ) SERVICE WATER PRE-OPERATIONAL - TESTING . SERVICE WATER VALVE POSITIONS - . CONCLUSION - . + .. , . .. . _. _ _ _. _.. _... _ _ _ _,. _.., _ _.. _ ......, .. _.. _, _ _ _. . _... _,. _ , _,,. _, _ -. _
. . - - .. . .. . _ _. __ - . -. _ . - . . .
, ORIGINAL DESIGN CALCULATIONS . <
CONFIRMED THERE EXISTED ADEQUATE . . PRESSURE AT THE ESSENTIAL HEAT EXCHANGERS WITH DESIGN FLOW BEING DELIVERED
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' SERVICE WATER PRE-OPERATIONAL TESTING i CONFIRMED THAT DESIGN FLOW COULD - l BE DELIVERED TO ALL ESSENTIAL HEAT EXCHANGERS , f . . -. .. .. . _ _ _. _ __ . ... .... - . - _. _. -... _.. _, ~,., - - - -
. . . _.
. .. . . - -. .. - . . - . SERVICE WATER VALVE POSITIONS
i i REVIEWED PRE-OPERATIONAL VALVE POSITIONS
' AGAINST CURRENT OPERATING VALVE LINE-UPS , FIELD VERIFIED A SAMPLE VALVE POPULATION j
MOST VALVES CURRENT POSITION MATCHED a l-PRE-OPERATIONAL TEST POSITION l l ) l THERE HAVE BEEN NO SIGNIFICANT VALVE - POSITION CHANGES THAT WOULD AFFECT FLOW i DEMAND, EXCEPT FOR THE COMPONENT COOLING ' WATER HEAT EXCHANGER SERVICE WATER VALVES (THROTTLED TO MAINTAIN ACCEPTABLE COMPONENT l COOLING WATER TEMPERATURES DURING NORMAL l ' OPERATION) '
1
MAJOR FLOW DEMAND COMPONENTS (i.e. DIESEL ' GENERATORS AND RCFC's) ARE TESTED OR VERIFIED TO HAVE SUFFICIENT FLOW TO REMOVE DESIGN HEAT LOADS ) ..,. . . . .. . - . -
_ _ _ - _ _ - . . L ' ! ) CONCLUSION DESIGN FLOW CAN BE
DELIVERED TO THE HEAT EXCHANGERS OPERATOR ACTION MAY BE - REQUIRED TO REMOVE DESIGN HEAT LOADS FOR COMPONENT ) COOLING HEAT EXCHANGERS ONLY (i.e., ADJUST SERVICE WATER FLOW TO MAINTAIN ACCEPTABLE COMPONENT COOLING WATER 1EMPERATURES DURING POST LOSS OF COOLANT ACCIDENT RECIRCULATION) ) l . . _ _ _ _ _ _ - _ _ _ _ _ - _ _ _ _ _ _ _ -
. . _ . l i . RELIABILITY OF SERVICE WATER MOTOR OPERATED VALVES TO BE ADDRESSED DURING MOV PRESENTATION ) )
- - - - - _ _ _ _ _ _ _ _ _ _
.. .. . f' ., SERVICE WATER SILTING . . COMPONENT COOLING HEAT EXCHANGERS
) MAJOR SERVICE WATER HEAT EXCHANGER
MAINTENANCE HISTORY CONCLUSION
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[ ' ! , i ) r
COMPONENT COOLING r HEAT EXCHANGERS '
i i . I JUNE 1990:
- 1 COMPONENT COOLING HEAT EXCHANGER
' + OPENED ANDINSPECTED . ! SILTING WAS OBSERVED IN THE HEAT EXCHANGER HEADS I
WITH NO SIGNIFICANT FLOW BLOCKAGE CONSEQUENCES r SILTING IS A SELF-LIMITING PHENOMENA AND IS
- BELIEVED TO HAVE REACHED ITS EQUILIBRIUM (MAXIMUM) VALUE FOR THIS HEAT EXCHANGER [ ) SUBSTANTIAL PERFORMANCE MARGIN IS AVAILABLE IN + COMPONENT COOLING WATER HEAT EXCHANGER & l l (i.e., DESIGN PERFORMANCE FACTOR IS 45%) COMPONENT COOLING WATER HEAT EXCHANGER SILTING - . IS EXPECTED TO BE WORST CASE BECAUSE: l
CLOSEST MAJOR LOAD TO SERVICE WATER PUMPS - l LOWEST ELEVATION OF ANY CONTINUOUS l - ' SERVICE WATER LOAD IN AUXILIARY BUILDING LOW TUBE SIDE VELOCITY - ' \\ u . - . . - -
I ' c.. . . i MAJOR SERVICE WATER HEAT EXCHANGER MAINTENANCE HISTORY 1. AFW OIL COOLERS CLEANED (EVERY REFUELING OUTAGE) 2. RCFC C0lLS REPLACED ON BOTH UNITS (1985) 3. 3 CHARGING PUMP ROOM COOLERS REPLACED (1986-1988) 1 RHR PUMP ROOM COOLER REPLACED (1986) . 4. DIESEL GENERATOR HEAT EXCHANGERS INSPECTED / REPLACED (DURING ENGINE OVERHAULS) ) 5. '0' COMPONENT COOLING WATER HEAT EXCHANGER CLEANED (1985) '1' COMPONENT COOLING WATER HEAT EXCHANGER CLEANED (1990) 6. NUMEROUS BOP HEAT EXCH ANGERS INSPECTED / CLEANED / REPLACED, INCLUDING: MAIN CONDENSERS GENERATOR SEAL OIL - - GENERATOR STATOR WA'IER GENERATOR HYDROGEN - TURBINE OIL - SERVICE AIR COMPRESSORS - INSTRUh!ENT AIR COMPRESSORS - )
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h ,;)b , , CONCLUSION
r ! ! , , i h . ALTHOUGH NO FORMAL PROGRAM WAS IN PLACE, NUMEROUS HEAT EXCHANGERS
HAVE BEEN INSPECTED AND CLEANED
) l
- GENERIC LETTER 89-13 PROGRAM WILL FORMALIZE HEAT EXCHANGER MAINTENANCE
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i ) i =.. _.,.. . .. . -. - . _ _ _ _.. _ _. _ _ -. _ _ _ _ _ _. _ _ _ _ _ _ _. _ _ _ _ _ _ _ _ _ _ _ _.. _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _. _, - - - - --
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T i
SERVICE WATER TESTING , ! , , .I r b , , TECHNICAL SPECIFICATION SURVEILLANCES
, . I L IN-SERVICE TESTING - )
CONCLUSION
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f . ! i-E . . . . .. _ _ . _ _ _ . - _ - , _ ..
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i i
, p r ! TECHNICAL SPECIFICATION SURVEILLANCES j ,
SERVICE WATER PUMPS MONTHLY TESTING VERIFIES
PUMP STARTS AND RUNS - ADEQUATE HEADER PRESSURE IS - MAINTAINED SATISFACTORY COOLING IS - MAINTAINED TO EQUIPMENT - PUMP BEARING TEMPERATURES - AND VIBRATION LEVELS ARE ACCEPTABLE , SERVICE WATER VALVES . MONTHLY / QUARTERLY / REFUELING
TESTING VERIFIES l ' VALVE ACTUATION " - VALVE MOTION - STROKE TIME - SERVICE WATER HEAT EXCHANGERS DAILY VERIFICATION OF FLOW RATE
AND RETURN PRESSURE FOR RCFC'S NO EXPLICIT REQUIREMENTS FOR
OTHER HEAT EXCHANGERS ,
] l . . _ _ _ _ _ _. - _ _ _ _ _ _ _ _ _ _ _ _. _. _ _ _, .. -. -.. - - . .. -...... -.. _
-,. ._.
.. - - - - .o , i . ,
) , IN-SERVICE TESTING . I
SERVICE WATER PUMPS
REFUELING VERIFIES AN ACCEPTABLE DIFFERENCE l
BETWEEN THE DESIGN AND THE MEASURED TOTAL DEVELOPED HEAD AT THE MEASURED FLOW RATE , SERVICE WATER. VALVES < ' MONTHLY / QUARTERLY / REFUELING TESTING )
VERIFIES AS APPROPRIATE: VALVE ACTUATION - VALVE MOTION - . STROKE TIME ' - POSITION INDICATION
- VALVE DISC LIFT - l l SERVICE WATER HEAT EXCHANGERS NO SECTION XI TESTING REQUIREMENTS
l } . - - -. - . -. - - . -. - - . - _ - --
-. - - -. - _ __ , . .. . ' , CONCLUSION l
>' i l l SERVICE WATER TESTING SATISFIED ! THE REQUIREMENTS OF THE TECHNICAL
SPECIFICATIONS AND ASME CODE L ! , ) .
- GENERIC LETTER 89-13 HAS HIGHLIGHTED TO THE INDUSTRY THE NEED TO ENHANCE
' SERVICE WATER PERFORMANCE MONITORING, , . ESPECIALLY FOR HEAT EXCHANGERS l . ' ) . - - - - .. -. -. -.
. - , l . - * e l ) ' GENERIC LETTER 89-13 PLANS IMPLEMENT AND MAINTAIN A PROGRAM -
TO REDUCE THE INCIDENCE OF FLOW BLOCKAGE . DEVELOP A HEAT EXCHANGER TEST - PROGRAM TO VERIFY HEAT TRANSFER ' CAPABILITY ) DEVELOP ANINSPECTION AND - , MAINTENANCE PROGRAM FOR SERVICE WATER PIPING AND COMPONENTS . REVIEW AND ENSURE THAT THE - SERVICE WATER SYSTEM WILL PERFORM ITS INTENDED FUNCTION
REVIEW TO ENSURE MAINTENANCE - PRACTICES, PROCEDURES AND TRAINING ARE ADEQUATE . - . <w-re - r-w e w-w.- , - -, ...m-.m__m,--- ,-. . -.- .- - -
,c . . Y SEMMARY THE SERVICE WATER PUMPS HAVE SUFFICIENT CAPACITY, + AND A SUFFICIENT NUMBER OF PUMPS WILL DE AVAILABLE, TO PROVIDE THE FLOW DEMANDED BY THE ACCIDENT + SCENARIOS WITH NO OPERATOR ACTION SYSTEM VALVES ARE ALIGNED IN SUCH A WAY THAT DESIGN - FLOWS CAN BE DELIVERED TO EACH OF THE ESSENTIAL HEAT EXCHANGERS HOWEVER,IT IS POSSIBLE THAT OPERATOR - ACTION MAY BE REQUIRED TO REMOVE DESIGN HEAT LOADS FOR THE COMPONENT COOLING WATER HEAT EXCHANGERS ) !
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SUMMARY i PUMP AND VALVE TESTING HAS SATISF1ED THE REQUIREMENTS . OFTHE TECHNICAL SPECIFICATIONS AND ASME CODE.
HOWEVER, TESTING PRACTICES WILL BE REVIEWED FOR ' ENHANCEMENTS.
-i . BASED ON LIMITED INFORMATION FROM OPERATING AND - MAINTENANCE HISTORY, AND THE RECENTINSPECTION OF , I THE COMPONENT COOLING WATER HEAT EXCHANGERS (WORST CASE), THE HEAT EXCHANGERS ARE ABLE TO PERFORM THEIR SAFETY FUNCTION. TESTING AND MAINTENANCE OF HEAT EXCHANGERS WILL BE IMPROVED WITH THE IMPLEMENTATION OF OUR GL 8913 PROGRAM ' ! < l l l ) i - - -- ._ . . . . - _.
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Zion Station Safety-Related Motor Operated Valves 464 TOTAL MOVs - 305 TOTAL SAFETY-RELATED MOVs
- 147 Unit 1 - 144 Unit 2 - 14 Common I 285 MOVs TESTED BY PROCEDURE
192 MOVs CURRENTLY IN IST PROGRAM
- STROKE TIMED AND TRENDED 55 MOVs TO BE EVALUATED FOR - ADDITION TO IST PROGRAM 70 MOVs COVERED BY IEB 85-03 - - 35 ON EACH UNIT ) - - - - - - - _ _ -- ----_ _ --- _ - _ - - - - _ _ _ - _ - - - - _ - - - - - - - - - - - - _ _ _ _ _ _ _ -
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?! IEB 85-03 Motor Operated Valves l TORQUE SWITCH SETTING DISCREPANCIES
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- UNIT 1:
15 MOVs INSPECTED (30 TOTAL SETTINO3,2 PE R MOV) l
._8 DISCR5 PANT TORQUE SWITCH SETTINGS _5 CONSERVATIVE DIRECTION ) _2 NON CONSEP.VATIVE DIRECIlON WITHIN OEM ! RECOMMENDED RANGE
- 1 NON CONSERVATIVE DIRECTION OUTSIDE ._ OEM RECOMMENDED RANGE i 29 WITHIN OEM RECOMMENDED RANGE .l
! 30 TOTAL SETTINGS -
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I , i . . ; hff . j . E . . / IEB 85-031 Motor Operated Valves j TORQUE SWfI'CH SETTING DISCREPANCIESi ' . . h , r
- UNIT 2:
j ' , , 33 MOVs INSPECTED (66 TOTAL SETIINGS,2 PER MOV)'
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_16 DISCREPANT TORQUE SWITCH SETTINGS l ( _9 CONSERVATIVE DIRECTION
L -) _6 NON CONSERVATIVE DIRECTION WITHIN OEM RECOMMENDED RANGE , - 1 NON CONSERVATIVE DIRECTION OUTSIDE _ OEM RECOMMENDED RANGE .; ^ t ?. 65 WITHIN OEM RECOMMENDED RANGE - , 66 TOTAL SETTINGS '
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. ' L') SCMMARY 2 DISCREPANCIES FOUND OUTSIDE OF OEM
- RECOMMENDED RANGE ALL DISCREPANCIES FOUND HAVE BEEN CORRECTED
, OPERABILITY DETERMINATION OF BULLETIN VALVES
PROVIDED IN RESPONSE TO CAL RIII 90-011 I.
COMMONWEALTH EDISON COMMTITED TO PERFORM A
RE-EVALUATION OF THE ZION IEB 85-03 MOVs IN THE CAL RESPONSE BY SEPTEMBER 1,1990 SETPOINT CONTROL PROGRAM PROCEDURE EXPANDED TO
TO INCLUDE MOV SETPOINTS AS DISCUSSED IN RESPONSE TO CAL RIH 90-011 PROCEDURE CHANGE COMPLETION SCHEDULED FOR: AUGUST I,1990 )
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NON EB 85-03' SAFETY-REL'ATED MOVS
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. ALL BUT 20 FON MB 85-03 SAFETY RELATED MOVs ARE ? . PERIODICALLY P.,TED FOR OPERABILITY UNDER NORMAL t SYSTEM CONDITIONS UTILIZING STROKE TESTING 46 0F 48 IEB 85-03 MOVs (96%) WERE FOUND WITH ! TORQUE SWITCH SETI'INGS WITHIN OEM RECOMMENDED RANGES. THESE NUMBERS PROVIDE CONFIDENCE THAT 96% OF THE NON IEB 85-03 SAFETY-RELATED MOVs -> ARE EXPECTED TO BE WITHIN OEM RECOMMENDED RANGES
ZION STATION WILL PRIORITIZE THE TORQUE AND BYPASS SWITCH INSPECTIONS OF THE NON IEB 85-03 SAFETY-RELATED MOVs THEREFORE, ZION STATION BELIEVES THAT THE PROPOSED 3 OUTAGE SCHEDULE IS ACCEPTABLE FOR -- THE COMPLETION OF INSPECTIONS OF TORQUE AND BYPASS SWITCH SETTINGS - , M - -
-) i . _-._-..-om.-_____ m
- _ _. -
__ - - -..., _ _....,, _,, . . +. , ) EXCEPTirNS: - THERE ARE 8 SAFETY-RELATED MOVs PER UNIT THAT ARE LOCATED BETWEEN THE TWO TECHNICAL SPECIFICATION AIR OPERATED CONTAINME C ISOLATION VALVES ON THE STEAM GENERATOR BLOWDOWN LINE, THEIR FUNCTION IS TO ISOLATE ) BLOWDOWN DURING MAINTENANCE ACTIVITIES.
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t - _ ,
\\ EXCElTIONS: ' - MOV VC8104 - THIS VALVE IS THE EMERGENCY BORATION - VALVE. THE UNIT 2 VALVE WILL BE STROKED PRIOR TO MODE 5 DURING THE PRESENT REFUELING OUTAGE. SINCE THE STROKING OF THIS VALVE COULD INJECT BORATED WATER INTO THE RCS, THE UNIT 1 VALVE WILL BE STROKED DURING THE NEXT HOT SHUTDOWN OUTAGE FOR THE LHIT.
MOV CC9415 IS THE SUPPLY TO THE NON-SAFETY RELATED - COMPONENT COOLING LOADS. THE UNIT 2 VALVE WILL BE STROKED PRIOR TO LEAVING MODE 5. SINCE THE STROKE OF THIS VALVE ISOLATES COMPONENT COOLING TO THE REACTOR COOLANT PUMPS, THE UNTT 1 VALVE WILL BE STROKED DURING THE NEXT REFUELTNG OUTAGE.
(PERIODIC TESTS FOR MOV VC8104 AND MOV CC9415 WILL BE , ADDED TO THE ZION PERIODIC TESTING PROGRAM.)
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- jj!: 'y SERVICE WATER.MOVs m r >
o , 66 TOTAL SAFETY RELATED SERVICE-L - L' WATER MOVs H l . ' l 70.0 VALVE STROKES (APPROXIMATELY) - , PER YEAR FOR TESTING { FAILURE HISTORY: 1988 - 6 FAILURES - 1989 - 6 FAILURES - 1990 - 2 FAILURES YEAR-TO-DATE - l i . - w . .. .. }}