ML19220A801
| ML19220A801 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 06/30/1978 |
| From: | Silver H Office of Nuclear Reactor Regulation |
| To: | Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 7904240627 | |
| Download: ML19220A801 (19) | |
Text
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.NUC:. EAR REGULATCRY CCMMissiCN t-t W ASHINGTCN. C. C. 20555 tM
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JUN 3 01978 Cocket No:
50-320 APPLICANT: Metropolitan Edison Ccmpany (Met Ed)
FACILITY:
Three Mile Island (TMI-2)
SUBJECT:
SLWARY OF MEETING CN STEAM GENERA ~iJR TUBE INSPECTION Respresentatives of the applicant and B&W met with members of the staff on January 25, 1973 to discuss results of the current examination on the TMI-2 steam generator tubes. A list of attendees is attached.
The meeting was informational in nature, and consisted primarily of a presentation by GPU personnel (see attached), examination of photographs, and discussion of the infomation presented. No significant deficiencies in the presentat_ ion were. identified.
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y H. Sil., Project Manager Light. ' Water Reactors Branch No.1 Divisii'in of Project Management
Enclosure:
Attendance List cc: See page 2 I_.'
1 7904040 M 70-018 9
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JUN 3 01978 Metrocolitan Ecisen Cccpa.y ccs:
George F. Trowericge, Esq.
Shaw, Pittman, Potts & Treweridge 1300 :4 Street, N. N.
Wasnington, C. C.
20036 Mr. I. R. Finfreck Jersey Central Power and Lignt Ccc:any Madisen Avenue at Puncn Scwl Road Merristown, New Jersey 07960 Mr. R. COnrad Pennsylvania Electric Cc=cany 1007 Srcad Street Jennstown, Pennsylvania 15907 Chauncey R. Kepford, Esq.
Chairman
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Ycrk Cccnittee for a Safe Environ:ent 433 Criando Drive State College, Pennsylvania 16a01
.ux. Ricnard W. !ieward Project Manager GPU Service Corporation 260 Cherry Hill read Parsippany, New Jersey 07054 Mr. T. Gary Srcughton Safety and Licensing Manager GPU Service Ccrporatien 260 Cherry Hill Fcad Pars ;peany, :iew Jersey 07054 7C"019 1
JUh :. :57S ATTENDANCE LIST C. Banwarth 3&W L. Pletke B&W P. Perrone S&W D. Levstek S&W F. Burke B&W H. Branner NRC J. Rajan NRC
- 3. Liaw NRC
-J. Strosnider NRC D. Slear GPVSC H. Silver
- NRC
- Denotes part-time attendance 70 020
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JUN 3 01978 TMI-2 OTSG EDDY CURRENT INSPECTICil RESULTS OVERVIEW OF TMI-2 EC1 EXAMINATION SUMPARY OF EDDY CURRENT INSPECTION RESULTS REMOVAL OF 4 TUBES FOR METALLURGICAL EXAMINATIC~l
SUMMARY
OF OTHER INDICATIONS NOTED ON OTSG TUBES CORRECTIVE ACTION TAKEN G
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OVERVI&l0F TMI-2 ECT E(AMINATION THE OBJECTIVE WAS TO BE IN A BtiitR POSITION TO INTERPRET FUTURE ECT EXAMINATI0ilS.
100% OF TUBES IN OTSG AaB WERE EXAtiltiED.
INSPECTION FREQUENCY WAS 400NiZ.
INITIAL IllSFECTION BY CONAM INSPECTION DIVISION OF NUCLEAR ENERGY SERVICES, IB!C.
CONAM DIRECTED BY GPUSC TO RECORD ALL ECT IllDICATI0ils NO MATTER HOW SMALL OR INi!OCUOUS.
ECT INDICATIONS GREATER thall 40% THROUGH WALL WERE
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~e REINSPECTED BY BOTH CONAM AND B&W.
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TUBE PLUGGING WAS BASED ON B&W'S EDDY CURRENT RESULTS.,
SUt91ARY TABLE OF TMI-II ECT INSPECTION RESULTS INDICATI0i1 OTSG-A OTSG-B f.
VERY SMALL Dit!G 68 47 SMALL DING 113 105 DI,NG 88 95 LARGE DING 107 87
<20%(>140LT) 38 23
< 20% (1 1 VOLT) 7 15 20% - 40% (1 1 VOLT) 2 10 1 40% (1 1 VOLT)
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7 15 1 40% (> 1 VOLT) 2 6
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70-023
MAJOR TYPES OF EDDY CURRENT INDICATICNS AT TMI-2 ECT SIGNALS SMALL IN Ar'.PLITUDE AT PHASE ANGLES INDICATIVE OF THROUGH 'dALL PENETRATION FROM
<20% TO 95%.
ECT SIGt!ALS LARGE IN AMPLITUDE AT PHASE ANGLES INDICATIVE OF THROUGH 'dALL PENETRATION
<20%.
ECT SIGNALS LARGE IN AMPLITUDE 'dITH UNDEFINED PHASE ANGLES.
ECT SIGNALS INDICATIVE OF A DING (I.E: REDUCTION OF INSIDE DIAfritR 'dITHOUT DETECTABLE REDUCTION IN WALL THICXNESS.)
70'024
O REF.0 VAL OF 4 TUBES FOR METALLURGICAL EXAMIf!ATIOil TYPE OF FCT Sir,3 L OHJFCTIVE SMALL AMPLITUDE IS DEFECT REAL?
> 40% THRU WALL LARGE AMPLITUDE WHAT IS DEFECT?
< 20% THRU WALL LARGE AMPLITUDE WHAT TUBE CONDITION UNDEFINED PHASE ANGLE GIVES THIS ECT SIGNAL?
DING CONFIRM THAT THIS ECT SIGNAL IS ACTUALLY AN I.D. REDUCTION OVERALL OBJECTIVES IDENTIFY CAUSE OF DEFECT INDICATIONS WAT TUEES M!)ST BE PLUGGED?
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9 RESULTS OF METALLURGICAL EXAMINATION TYPE OF ECT SIGNAL TUBE CONDITI0tl SMALL AMPLITUDE SCAB AT LEAST 55% THRU 'dALL 36% THRU ALL LARGE AMPLITUDE VARYING 0.D. REDUCTION
< 20% THRU WALL OVER ABOUT 8 INCH AXIAL LENGTH MAXIMUM REDUCTION ABOUT 10 MILS DIFr h 4 M -.
CFI% OF WALL THICKNESS)
'/bb LARGE AMPLITUDE VARYING 0.D. REDUCTION UNDEFINED PHASE ANGLE OVER ABOUT 8 INCH AXIAL LENGTH MAXIMUM RED QUCT ON ABOUT 5 MILI N OF WALL THICKNESS)
DING 2 LOCATIONS OF -I.D.
REDUCTION UNDER 0.D.
GRIND MARKS 70~02G
SIGNIFICANCE OF METALLURGICAL EXAMINATION SMALL AMPLITUDE ECT SIGNALS ARE INDICATIVE OF REAL DEFECTS.
TUBES CONFIRMED BY BaW TO HAVE DEFECTS : 40% THRU WALL HAVE BEEN PLUGGED.
PRELIMINARY RESULTS OF B&W'S MANUFACTURING REVIEW GIVES REASONABLE ASSURANCE THAT THE TUEE CONDITIONS NOTED CAN OCCUR DURING MANUFACTURE OF TUEES AND OTSG.
0.D. REDUCTIONS DO NOT VIOLATE TUBE MINIMdM WALL REQUIREMENTS AND TUEES WITH THIS TYPE OF ECT INDICATION CAN BE LEFT IN SERVICE.
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SUMPARY OF OTHER INDICATIONS SMALL SPOTS OF A SURFACE DE?0 SIT WERE NOTED ON TUBE REF.0VED FROM UPPER TUBESHEET.
1)
EDAX INDICATED SULFUR.
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B&W TO CHARACTERIZE COMPOUNDS.
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3)
GPU TO PERFORM COLD SOAK OF OTSG IF NECESSARY.
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+.-p ABOUT 1/3 0F TUBES IN OTSG B EXHIBIT ECT t10lSIER THAN REPAINING TUBES.
1)
BOTH B&W AND CONAM CONFIRM TUBES CAN BE INSFECTED WITH EDDY CURRENT.
2)
CONF 1 HAS "EMONSTRATED THAT NOISE CAN BE SUPPRESSED S0.'EWHAT USING A PROBE WOUND AROUND A PERFANENT MAGNET (SATURATED PROBE).
3)
ECT INDICATICNS WITH AMPLITUDES LESS THAN ABOUT.3 VOLT CAN BE MASTED.
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SUMMARY
OF OTHER IllDICATICils ABOUT 5% OF TUEES EXHI3IT I.D. TUEE CHATTER OVER SOME FORTICII 0F THEIR LENGT!!.
1)
LARGE MAGNITUDE SIGNAL WHICH CAfl MASK DEFECTS.
2)
ECT SIGNAL SIMILAR TO THAT CAUSED BY PERMEABILITY CHANGE E'(CE?T THAT IT PERSISTS OVER MORE AXIAL LENGTH.
3)
EITHER ECT SHOULD BE MODIFIED TO REDUCE SENSITIVITY TO I.D. TUEE CHAllt.R OR ELSE ANOTHER INSPECTION TECHNIQUE IS NEEDED (?OSSIBLY UT) WHICH IS NOT MASKED BY THIS TUEE CONDITION.70-029
SUP!9ARY OF CORRECTIVE ACTICN ALL TUEES CONFIRP.ED BY B&W ECT TO HAVE DEFECT INDICATI0ilS
- 2. 40% HAVE BEEi PLUGGED. [3b LARGEST DING [NDICATIONS HAVE BEEN CHARACTERIZED WITH AN I.D.PROFIL0METERTO'dITHIN5.002 INCHES.
Ba'd HAS ANALYZED THE DillG GEOMETRY AND CONCLUDED THAT TUBES WITH DINGS CAN BE LEFT Ill SERVICE.
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SUMPARY TABLE OF TMI-II OTSG TUEES PLUGGED REAS0il 0TSG - A OTSG - B 2.40% (1 1 VOLT)
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7 15 a 40% (> 1 VOLT) 2 6
IllSTRUME?ti TESTIllG 1
MISTAKE 2
TUBE SAMPLES 4
TOTAL 13 24 9
A 6
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'70- 031