ML20036B788
| ML20036B788 | |
| Person / Time | |
|---|---|
| Site: | Zion File:ZionSolutions icon.png |
| Issue date: | 05/26/1993 |
| From: | Stimac S COMMONWEALTH EDISON CO. |
| To: | Murley T NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM), Office of Nuclear Reactor Regulation |
| References | |
| GL-89-10, NUDOCS 9306020336 | |
| Download: ML20036B788 (7) | |
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) 1400 Opus Place C:mm:nwrith Edinn r1
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Downers Grove, Illinois 60515 s
May 26,1993 Dr. Thomas E. Murley, Director Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington, D.C. 20555 Attn: Document Control Desk
Subject:
Zion Station Units 1 and 2 NRC Diagnostic Evaluation 3
Su lemental Information N
_Qocket Nos. 50-295 and 50-304
References:
November 2,1990 letter from Cordell Reed to James Taylor August 28,1991 letter from S.F. Stimac to T.E. Murley c
September 12,1991 meeting with W. Schafer and M. Farber at Zion Station (d) December 2,1991 letter from S.F. Stimac to T.E. Murley (e) July 24,1992 letter from S.F. Stimac to T.E. Murley
Dear Mr. Murley:
References (a) through (e) provided CECO's response to the NRC's diagnostic evaluation of Zion Station, supplemental information, and various updates to the status of DET commitments.
As of this date,102 of 113 DET commitments are complete. Attachment 'A' is a complete list of the remaining 11 DET commitments with the current planned completion date. Of the 11 remaining DET commitments,6 will be comp'eted by the end of the second quarter in 1994. The remaining 5 commitments are scheduled for completion between 1995 and 1996. Each commitment discussed in the attachments is indexed by the item number utilized in reference (a).
Of the 6 commitments expected to be completed by the end of the second quarter 1994, five of these are tied to completion of the upcoming Dual Unit Service Water Outage. Specifics on those commitments requiring additional time for completion (beyond that previously communicated) are provided in Attachment 'B'.
t 020034 9306020336 930526 PDR ADOCK 05000295 1
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Dr. Mudey May 26,1993 In addition, it should be noted that CECO is presently re-evaluating the Zion improved Technical Specification :>roject (Action item # DET 2.3.01.07). Where this re-evaluation is complete, the resu ts will be communicated to NRC via separate correspondence.
j Please direct any questions regarding this matter to this office.
Respectfully, v
v S.F. Stimac i
Nuclear Licensing Administrator E
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A. Bert Davis, Regional Administrator - Rill C.Y. Shiraki, Project Manager - NRR J.D. Smith, Senior Resident Inspector - Zion r
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ATTACHMENT *A*
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ZION STATION DET OPEN ITDi3
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ITEM NO.
DESCRIPTION CURRENT COMPLETION
.DATE i
1 DET2.2.04-01 DET RESPONSE - INSTALL MOV LIMITER 6/30/94 PLATES AS PLANT CONDITIONS ALLOW.
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2 DET2.2.05-01 DET RESPONSE - INSTALL 4 ROTOR 2/28/96 LIMIT SWITCH WIRING FOR ADDITIONAL
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DET2.2.07-01 DET RESPONSE - DIAGNOSTICALLY TEST 2/28/96
.l ALL MOV'S IN THE SCOPE OF GENERIC LETTER 89-10 4
DE"'2. 2. 0 8 - 01 DET RESPONSE - CLEAN OR TEST ALL 3/31/94 SAFETY RELATED SERVICE WATER HEAT j
EXCHANGERS TO ENSURE DESIGN HEAT j
TRANSFER CAPABILITY.
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DET2.2.08-03 DET RESPONSE - INITIAL 2/28/96 l
IMPLEMENTATION OF GL 89-13 REQUIRDiENTS.
6 DET2.3.01-03 DET RESPONSE - COMPLETE ALL FUSE 3/31/94
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WALKDOWNS.
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7 DET2.3.01-07 DET RESPONSE - IMPLEMENT MERITS.
6/30/94 8
DET2.3.01-08 DET RESPONSE - CONSOLIDATE 12/31/96 EXISTING DESIGN BASIS INFO INTO CONCISE SYSTEM AND TOPICAL
'i PACKAGES, ESTABLISH PROCESS TO MAINTAIN PACKAGES AS CONTROLLED DESIGN DOCUMENTS AND DEVELOP COMPUTERIZED DESIGN DATABASE.
9 DET2.3.04-01 DET RESPONSE - RECONFIRM FSAR AND 6/30/9E SER CONCLUSIONS REGARDING ADEQUACY
~l OF TWO SW PUMPS.
j 10 DET2.3.06-01 DET RESPONSE - PERFORM AN 6/30/94 l
EVALUATION TO DETERMINE THE OPTIMUM VALVE-POSITION FOR THE CCW HEAT EXCHANGER SW VALVES.
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11' DET2.3.06-03 DET RESPONSE - IMPLDIENT PROGRAM 6/30/94 TO CONTROL SW VALVE POSITIONS.
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ATTACHMENT
'B' ACTION ITEM #:
2.2.08-01 DET DESCRIPTION:
THE LICENSEE DID NOT KNOW THE CONDITION OF SEVERAL SAFETY-RELATED SW HEAT EXCHANGERS r
ACTION ITEM:
CLEAN OR TEST ALL SAFETY-RELATED SERVICE WATER HEAT EXCHANGERS TO ENSURE DESIGN HEAT TRANSFER CAPABILITY t
'I STATUS:
ACTION ONGOING l
t PREVIOUS COMPLETION DATE:
3-15-93 REVISED COMPLETION DATE:
3-31-94
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SUMF.ARY :
AS OF 3-15-93, 60 OF 66 SAFETY RELATED HEAT EXCHANGERS HAVE BEEN CLEANED AND INSPECTED.
FOUR-OF THE SIX REMAINING KERE DEFERRED DUE TO ISOLATION VALVE LEAK-BY RESULTING IN AN INABILITY TO
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COMPLETELY ISOLATE THE HEAT EXCHANGERS. THESE SIX HEAT EXCHANGERS WILL ALL BE CLEANED AND INSPECTED l
PRIOR TO THE END OF T"E DUAL UNIT SERVICE WATER
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OUTAGE.
IN ADDITION, THE VALVES LEAKING BY ARE SCHEDULED TO BE REPLACED DURING THE UPCOMING DUAL
- I UNIT SERVICE WATER OUTAGE.
I TESTING OF UNIT 1 SW HEAT EXCHANGERS IS COMPLETE-AND ONLY TWO UNIT 2 SW HEAT EXCHANGERS STILL i
REQUIRE TESTING. ALL NECESSARY. TESTING IS
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SCHEDULED TO BE COMPLETE PRIOR TO THE START OF THE DUAL UNIT SW OUTAGE IN SEPTEMBER 1993.
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ATTACHMENT *B' l
a ACTION ITEM #:
2.3.01-03 LET DESCRIPTION:
THE SW SYSTEM DESIGN BASIS WAS NOT WELL DOCUMENTED
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OR UNDERSTOOD.
v ACTION ITEM:
COMPLETE WALKDOWN TO EVALUATE INFORMATION IN THE FUSE LIST AGAINST ACTUAL PLANT CONDITIONS l
i STATUS:
ACTION ONGOING PREVIOUS COMPLETION DATE:
3-31-93 REVISED COMPLETION DATE:
3-31-94 i
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SUMMARY
AS OF 3-31-93, 981 (1,850 OF 1,895) OF ALL SAFETY RELATED FUSES HAVE-BEEN VERIFIED. -THE REMAINING _
FUSE WALYm WNS ARE SCHEDULED TO BE COMPLETE BY THE END OF THE UPCOMING DUAL UNIT OUTAGE.
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'B' 2.3.04-01 ACTIO!! ITDO :
THE ZION STATION SERVICE WATER SYSTD4 WAS NOT DET LESCRIPTION:
MIALYZED FOR A TWO PUMP ACCIDDIT SCENARIO RECONFIRM FSAR AND SER CONCLUSIONS REGARDING ACTION ITD4:
ADEQUACY OF TWO SERVICE WATER PUMPS ADDITIONAL ACTION PD; DING COMPLETION OF COMMITMENT DET2.3.06-03 (SERVICE WATER VALVE POSITION CONTROL STATUS:
PROGRAM) AND REPLACD4ENT OF SERVICE WATER PUMP IMPELLERS WITH IMPROVED DESIGN IMPELLERS.
PREVIOUS COMPLETION DATE:
3-31-93 REVISED COMPLETION DATE:
6-30-95 SPECIFIC CONTROLS TO ENSURE ADEQUACY OF SERVICE SUIGiARY :
WATER FLOW FOR THE TWO PUMP ACCIDENT SCENARIO ARE IN PLACE VIA ADMINISTRATIVE TECHNICAL M1 ANALYSIS OF THE SERVICE WATER SPECIFICATIONS.
SYSTEM HAS EEEN COMPLETED FOR BOTH THE CURRENT SYSTEM ARPJd1GEMENT AND FOR THE ANTICIPATED POST DUAL UNIT SERVICE WATER OUTAGE (DUO) ARRANGEMENT.
IT HAS BEEN DECIDED THAT IN ORDER TO ENSURE PUMP SUFFICIENT SERVICE WATER FLOW FOR THE TWO ACCIDENT SCENARIO WITHOUT THE CURRENT ADMINISTRATIVE CONTROLS, ZION WILL COMPLETE REPLACEMENT OF ALL SERVICE WATER PUMP IMPELLERS (IN SOME CASES THE WITH AN IMPROVED DESIGN IMPELLER EXISTING IMPELLERS ARE BEING REUSED AFTER EEING REWORKED TO THE IMPROVED DESIGN SPECIFICATION).
THIS IMPROVED DESIGN I!NOLVES IMPELLER VMJE TIP UNDERFILING, CONTOURING OF IMPELLER VANES, AND CURRENTLY, THREE POLISHING OF IMPELLER SUPTACES.
TWO SW PUMPS HAVE RECEIVED THIS UPGRADE.
IsDDITIONAL PUMPS ARE SCHEDULED FOR THIS UPGRADE DURING THE SPRING OF 1994, AND THE FINAL PUMP IS TO EE UPGRADED DURING THE SPRING OF 1995.
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ACTION ITD9 :
2.3.06-01 DET DESCRIPTION:
VALVES WERE NOT ADJUSTED TO BALANCE FLOW IN THE SERVICE WATER SYSTEL
. ACTION ITEM:
CECO WILL PERFORM AN EVALUATION TO DETERMINE THE OPTIMUM VALVE POSITION FOR THE CCW HEAT EXCHANGER SW VALVES, IN ORDER TO SATISFY THE OBJECTIVES OF MAINTAINING ACCEPTABLE CCW TEMPERATURES AND MINIMIZING THE OPERATOR ACTIONS THAT MUST BE TAKEN TO ESTABLISH POST-LOCA RECIRCULATION. THIS EVALUATION WILL BE COMPLETED BY DECEMBER 31, 1990.
t STATUS:
ACTICN ONGOING PREVIOUS COMPLETION DATE:
1-15-93 f
i REVISED COMPLETION DATE:
6-30-94 r
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SUMMARY
AS STATED IN THE PREVIOUS UPDATE FOR THIS COMMITMENT
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PROVIDED IN REFERENCE B, THE INITIAL REPORT FOR THIS COMMITMENT WAS ISSUED BY THE ORIGINAL DUE DATE.
HOhT/ER, BASED ON THIS DEPORT IT WAS DECIDED THAT ADDITIONAL STUDY OF THE ISSUE WAS APPROPRIATE.
i AT FOLLOW UP MEETINGS WITH STATION PERSONNEL, A DIFFERENT f
APPROACH TO SOLVE THIS PROBLEM WAS ADOPTED AND WESTINGHOUSE WAS CONTRACTED TO PERFORM ANALYSES ON EQUIPMENT COOLED BY CCW WITH THE GOAL OF DETERMINING WHETHER CCW VALVES COULD i
BE MAINTAINED FULL OPEN AT ALL TIMES.
TEE WESTINGHOUSE STUDY WAS COMPLETED ON DECEMBER 20, 1991. THIS STUDY r
4 CONCLUDED THAT 'iHE CCW SYSTEM COULD BE SAFELY OPERATED DOWN j
TO TEMPERATURES AS LOW AS 40 DEGREES F.
BASED ON THIS i
INFOR!'_ATION, A SW FLOW VALUE OF 8,000 GPM THROUGH THE CCW I
HEAT EXCHANGERS WAS DETERMINED TO BE OPTIMAL. TO ACHIEVE i
THIS FLOW, IT IS NECESSARY TO THROTTLE SW FLOW THROUGH THE CCW HEAT EXCHANGERS AND MAINTAIN CONTROL OVER APPROPRIATE l
SW VALVE POSITIONS. THE SW VALVE POSITION CONTROL PROGRAM IS NOW SCHEDULED TO BE IN PLACE FOLLOWING THE UPCOMING DUAL UNIT OUTAGE, BUT NO LATER THAN 6-30-94.
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THIS COMMITMENT IS BEING KEPT OPEN UNTIL THE PROGRAM TO CONTROL SW VALVE POSITIONS IS IN PLACE ON 06/30/94 (SEE
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COMMITMENT #2.3.06-03).
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ATTACHMENT
'B' ACTION ITa4#:
2.3.06-03 DET LESCRIPTION:
VALVES WERE NOT ADJUSTED TO BALANCE FLOW IN THE SERVICE WATER SYSTD4.
ACTION ITEM:
THE SYSTEM FLOW MODEL WILL THDI BE USED TO ESTABLISH A PROGRAM FOR THE CONTROL OF FLOW / VALVE POSITIONS. A PROGRAM TO CONTROL VALVE POSITIONS WILL BE COMPLETED BY 9/30/91.
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STATUS:
ACTION ONGCING PREVIOUS COMPLETION DATE:
I-15-93 REVISED COMPLETION DATE:
6-30-94
- SUMiiARY:
AS INDICATED IN PREVIOUS UPDATES, SIGNIFICANT CHALLENGES HAVE BEEN ENCOUNTERED IN ATTEMPTING TO IMPLEMENT A PROGRAM TO CONTROL THE POSITION OF VALVES IN THE SERVICE WATER (SW)
SYSTD4.
t AS PART'OF THE PLAN FOR COMPLETING THIS COMMITMENT, ATTD4 PTS WERE MADE TO THROTTLE THE SW ISOLATION 7ALVES FOR THE COMPONENT COOLING WATER HEAT EXCHANGERS. BECAUSE OF j
THE DESIGN AND CONDITION OF THOSE VALVES, THE THROTTLING ATTEMPTS RESULTED IN UNDESIRABLE VIBRATION AND PACKING LEAKAGE. AFTER SEVERAL UNSUCCESSFUL ATTEMPTS TO ALLEVIATE i
THESE PROBLEMS, IT HAS BEEN DECIDED TO DEFER ANY ADDITIONAL ATTEMPTS AT THROTTLING THESE VALVES UNTIL AFTER THE REPLACEMENT OF THESE VALVES DURING THE UPCOMING DUAL UNIT I
SW OUTAGE (DUO). FOR EACH HEAT EXCHANGER, A SINGLE SW OUTLET ISOLATION VALVE WILL BE REPLACED WITH A SEPARATE THROTTLE AND ISOLATION VALVE.
THE ZION MANAGEMENT ACTION PLAN DEVELOPED FOR THIS
.i COMMITMENT HAS BEEN REVISED TO INCLUDE RE-MODELLING THE SW SYSTEM USING DETAILED DATA NOW AVAILABLE FOR THE NUMEROUS
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MODIFICATIONS AND VALVE REPLACEMENTS THAT ARE SCHEDULED FOR THE DUO.
POST OUTAGE SYSTD4 TESTING AND FLOW i
BALANCING / VERIFICATION ARE INCLUDED AS A PART OF THIS REVISED ACTION PLAN.
THE REVISED COMPLETION DATE FOR THIS f
COMMITMEJT IS 6-30-944 j
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