ML17055C544

Summary of 860924 Meeting W/Util & MPR Assoc Re Status of CRD Penetration Repair Program.List of Attendees & Slide Presentation Encl

ML17055C544
Person / Time
Site:	Nine Mile Point
Issue date:	10/07/1986
From:	Joseph Kelly Office of Nuclear Reactor Regulation
To:	Office of Nuclear Reactor Regulation
References
NUDOCS 8610220441
Download: ML17055C544 (92)

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UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D. C. 20555 October 7, 1986 Docket No. 50-220 LICENSEE:

Niagara Mohawk Power Corporation FACILITY:

Nine Mile Point Nuclear Station, Unit No.

1

SUBJECT:

SEPTEMBER 24, 1986 MEETING WITH NIAGARA MOHAWK POWER CORPORATION (NMPC)

TO DISCUSS STATUS OF THE CONTROL ROD DRIVE PENETRATION REPAIR PROGRAM On September 24, 1986, the staff met with representatives of Niagara Mohawk Power Corporation (NMPC), the licensee, and their consultant, MPR Associates, to discuss the status of the repair program for the leaking control rod drive (CRD) penetrations at the Nine Mile Point Nuclear Station, Unit No.

1 (NMP-1).

A list of attendees is attached as Enclosure l.

Enclosure 2 is a copy of the slides used by the licensee in its presentation of the repair program under consideration.

The licensee, in its presentation, discussed the background of the CRD penetration problem.

In short, ten CRD penetrations (stub tubes) were rolled during the 1984 refueling outage.

In October

1984, NMPC informed the staff of the development of an in-service inspection program for the CRD penetrations.

This program included visual inspection for leakage during hydrostatic tests at refueling outages, close circuit TV inspection of stub tube cracking, and ultrasonic testing of at least two previously rolled housings.

In a meeting held with the staff on November 18,

1985, NMPC presented guidelines for the repair of the leaking CRD penetrations.

During the 1986 refueling outage, one CRD housing was rolled for the first time and two housings were rerolled (had previously been rolled in 1984).

During the August 8, 1986 maintenance

outage, an additional CRD housing was rolled successfully.

All the penetrations repaired in 1984 and 1986 successfully passed post repair pressure tests with no leakage.

NMPC proposed that the repair method and the leakage limits presented to the staff in Table 1 of Enclosure 2, provides assurance of the stub tubes acceptability for continued operation.

In addition, inspection of the CRD penetrations will also be conducted during nonrefueling outages in which drywell entries are made.

NMPC informed the staff that the determination to roll or reroll a penetration will be evaluated on a case-by-case

basis, and that operation with known leakage will be allowed with up to 0.1 GPM leaking from any one penetration.

The total leakage during hydrostatic pressure tests will be limited to 1.0 GPM from all penetrations.

NMPC is seeking approval of their guidelines in the near term.

In parallel with these actions, NMPC has initiated a development program to design and qualify a backup mechanical seal assembly for CRD penetrations which may exceed the leakage criteria if rollinq efforts are unsuccessful.

The first phase of this work including the design, fabrication, and testing PDR ADOC 861007 86102gp+<1 p

K 05000gpp PDR l

a a

of a prototype mechanical seal was recently completed.

The final stage of development is underway and involves the development of seal installation tooling.

NMPC estimates this work will be completed and that the feasibility and practicality of the backup mechanical seal will be demonstrated within approximately 8 months.

NMPC proposes that the seal repairs be implemented only if rolling is unsuccessful and informed the staff that the estimated time to prepare for seal installation after a decision to implement is 24-30 months.

Original signed by

Enclosures:

As stated Janet L. Kelly, Project Manager BWR Project Directorate kl Division of PWR Licensing DISTRIBUTION NRC PDR Local PDR see attached list DBL:BMDl CJamerson

]b/o&/86 DBL:BMDlJK JKelly/pn l0/0+86 DBL B

RHermann l6/ ( /86 DBL:

Dl JZwolinski y / t,/86

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Niagara Mohawk Power Corporation Nine Mile Point Nuclear Station, Unit No.

1 CC:

Troy B. Conner, Jr., Esquire Conner 5 Wetterhahn Suite 1050 1747 Pennsylvania

Avenue, N.

W.

Washington, D. C.

20006 Frank R. Church, Supervisor Town of Scriba R. D.

P.2

Oswego, New York 13126 Niagara Mohawk Power Corporation ATTN:

Mr. Thomas Perkins Plant Superintendent Nine Mile Point Nuclear Station Post Office Box 32

Lycoming, New York 13093 Resident Inspector U. S. Nuclear Regulatory Commission Post Office Box 126

Lycoming, New York 13093 John W. Keib, Esquire Niagara Mohawk Power Corporation 300 Erie Boulevard West

Syracuse, New York 13202 Regional Administrator, Region I U. S. Nuclear Regulatory Commission 631 Park Avenue King of Prussia, Pennsylvania 19406 Mr. Jay Dunkleberger Division of Policy Analysis and Planning New York State Energy Office Agency Building 2 Empire State Plaza

Albany, New York 12223 Niagara Mohawk Power Corporation Attn: Mr. C. V. Mangan Senior Vice President c/o Miss Catherine R. Seibert 300 Erie Boulevard West

Syracuse, New York 13202

0

FNCLOSURE 1

SEPTEMBER 24, 1986 - MEETING WITH NMPC TO DISCOSS LEAKING CONTROL ROD DRIVE PENETRATIONS Name Janet Kelly Raymond J. Pasternak Robert Hermann Bill Schmidt T. J. Perkins C. V. Mangan T.

W.

Roman S.

W. Wilczek, Jr.

Peter Francisco H.

Wm. McCurdy Rrian L. Lipford John A. Zwolinski H. F. Conrad H. K. Shaw W. S. Hazelton Yueh-Li Li Paul Cortland Lee Klosowski Affiliation NRC/DBL/BWD-1 NMPC NRC/DRL/BWR Eng MPR NMPC NMPC NMPC NMPC NMPC MPR MPR NRR/DBL/BWD1 NRP/DBL/BEB NRR/DBL/BEB NRR/DBL Eng NRR/DBL/BEB NRC/OI F.

NMPC Title Project Manaoer Mgr-Nuc Consulting Section Leader Enqineer Gen. Supt.

Sr. V.P.

Station Supt.

NMP-1 Manager Nuclear Technology Lead Licensing Eng.

Enqineer

'ngineer Proiect Director IGSCC Pgm Mgr.

Metallurgist Lead Mechanical Engineer

NIAGARA MOHAMK POtttER CORPORATION NINE MII E POINT UNIT NO.

1 CONTRO 0

R VE PENETRAT ON REPA PRO RA STATUS REPORT SEPTEMBER 1985

0

OUT I HE OF P RESENTAT I OH NHP-CRD PEiNETRATION REPA R

PRO RAM I.

NTRODUCT ON AND BA~

ROUND A.

P URPOSE B.

PLANT DESCRIPTION C.

CRD PENETRATION DESCRIPTION D,

DESCRIPTION OF PROBLEM I I, H STOR OF EYALUAT I ONS /STAT S

OF REP A I RS A.

CONTINGENCY Pl ANS AND INYESTIGATIONS COMPLETED

'RIOR TO SPRING 1984 OUTAGE B.

INSPECTIONS AND REPAIRS TO CRD PENETRATIONS IN SPRING l984 OUTAGE 1.

I NSPE CT I ONS 2.

ROLL REPAIRS C.

CONTINGENCY PLANS AND INVESTIGATIONS TO PREPARE FOR SP R I NG 1986 OUTAGE

, 1.

DEYEl OP MENT OF ROLL REPAIR I i"fP ROYEi"lENTS 2.

IN-SERYI CE INSPECTION PROGRAM 3.

GUIDELINES FOR REPAIR OF LEAKING PENETRATIONS

t

D, INSPECTIONS AND REPAIRS TO CRD PENETRATIONS DURING SPRING 1986 OUTAGE 1.

INSPECTIONS 2,

ROLL REPAIRS E.

RECENT REPAIR/CURRENT STATUS F,

CODE COMPLIANCE AND LICENSING BASIS FOR REPAIR APPROACH I I I.

BA UP ECHAN CAl SEAL DEVE OP ENT PRO RAN A.

P URP OSE FOR ME CHAN I CAL SEAL DEYELOP MENT B.

CE SEAL DEYELOPMENT C.

MPR MECHANICAL SEAL DEYELOP MENT PROGRAM MAIN FEATURES OF SEAL D.

CODE AND LICENSING BASIS FOR MECHANICAL SEAL E.

DEYELOPMENT STATUS OF MPR MECHANICAL SEAL IV, FUTURE PLANS FOR CRD REPA R

PRO RAM

I, I NTRODUCT ON AN BA ROUND A.

P URP OSE:

REVIEM BACKGROUND AND STATUS OF CRD

.PENETRATION LEAKAGE PROBLEMS REACH AGREEMENT ON NMPC PLANS AND CRITERIA LEAKAGE CRITERIA INSPECTION PLAN REPAIR CR.ITERIA

. SUMMARIZE CONTINGENCY REPAIR PROGRAM B.

PLANT DESCRIPTION:

BMR 1850 MH(T), 610 MM(E)

BEGAN COMMERCIAL OP ERAT I ON IN 1969 lOCATED ON THE SOUTHEAST SHORE OF LAKE ONTARIO IN OSMEGO

COUNTY, NEM YORK OPERATING CONDITIONS; 550 OF, 1030 PSIG

~v '

NTRODU TION AN A

RO ND CON'D C.

CRD PENETRATION DESCRIPTION:

0 l29 CRD PENETRATIONS IN LOMER HEAD STUB TUBES 304 SS~

7 1/2 " OD, 3/0 " MALL CRD HOUSINGS - 300 SS, 6" OD, 1/2".

MALL STUB TUBE-TO-VESSEL MELD - PARTIAL PENETRATION INCONEL SHOP MELD CRD HOUSING-TO-STUB TUBE MELD 308 SS PARTIAL PENETRATION FIElD MELD

304SS Held 1.12 to 4. 93" 304SS Stub Tube (Furnace Sensitized) 304SS Cladding Znconel Weld 304SS CH) Housing Alloy Carbon Steel Vessel NMP-I CRD PENETRATjON

0

D.

DES R PT ON OF PROB E

CRD PENETRATION LEAKAGE AS A RESULT OF:

1.

STUB TUBES MERE FABRICATED FROM 300 SS AND HEAT TREATED (SENS ITIZED) MITH VESSEL DUR I NG FABRICATION.

2.

STRESS CORROS ION CRACKS DEVELOPED IN STUB TUBES DURING PLANT OPERATION, THROUGH-MALL CRACKING OF STUB TUBE CREATES LEAK PATH BETWEEN O.D.

OF HOUS.ING AND VESSEL BORE PENETRATION.

C,

II.

H STOR OF EYA ATIONS/STAT S OF REPA RS A.

ONT N

N P

ANS AN Y ST AT ONS 0

P TE PRIOR TO SP IN OUTA E INYESTIGATIONS MERE PERFORMED FOR THE PURPOSE OF:

EVALUATING THE POTENTIAL FOR CRACKING OF THE NMP-1 STUB TUBES BASED ON RELATED EXPERIENCE AT OTHER BMR PLANTS EYAlUATING THE SAFETY IMPLICATIONS OF STUB TUBE. CRACKS/lEAKS EYALUATING ALTERNATIYE CRD PENETRATION INSPECTION AND REPAIR TECHNI QUES DEYELOP ING CONTINGENCY PLANS AND TOOLING FOR INSPECTION AND REPAIR OF'NMP-1 CRD PENETRATIONS DURING SPRING 1984 OUTAGE

SAFETY IMPLICATIONS OF STUB TUBE CRACKS/LEAKS MERE REVIEMED AND FOUND NOT TO BE A SIGNIFICANT SAFETY CONCERN SINCE:

THE STRUCTURAL INTEGRITY OF THE REACTOR VESSEL P RESS URE BOUNDARY I S NOT AFFECTED.

THE ABILITY OF THE CRD PENETRATIONS/HOUSINGS TO PERFORM THE DESIGN FUNCTIONS HAS NOT CHANGED:

THERE IS NO ADVERSE EFFECT ON CRD OPERATION OR ABILITYTO SCRAM.

PLANT OPERATION OR SAFE SHUTDOMN IS NOT AFFECTED.

CRD HOUSING EJECTION IS NOT POSSIBLE SINCE:

A, THE HOUSING-TO-STUB TUBE MELD IS

INTACT, B.

THE STUB TUBE IS LOADED IN COMPRESSION AND IS NOT AFFECTED 8 Y CRACKS.

C, A MECHANICAL RESTRAINT SYSTEM IS PROVIDED UNDERNEATH THE LONER VESSEL HEAD TO PREVENT EJECTION (SHOOT-OUT-STEELO.

l EAKAGE FROM THE PENETRATIONS IS SMALL (DROPS PER MINUTE) AND CAN BE MONITORED BY EXISTING DRY NELL LEAKAGE MONITORING SYSTEMS (1/0 GPM SENSITIVITY)

ALTERNATIVE REPAIR APPROACHES MERE EVALUATED HHICH INCLUDED:

EXPANSION.ROLLING OF THE CRD HOUSING INTO THE VESSEL BORE GENERAL ELECTRI C LONG-TERN F I X I NVOLVI NG REMOTE MACHINING OF STUB TUBE AND LONER HEAD, INSTALLATION OF DRY CAISSON, COMPUTER CONTROLLED REMOTE MELDING OF A STUB TUBE SLEEVE t

MECHANI CAL PACK I NG/GASKET REPAIRS,I NVOLVI NG INSTAI LATION OF EXTERNAL. AND/OR INTERNAL SEALS CE TYPE INTERNAL SLEEVE/PACK I NG I NSTALLATI ON

I

~

THE EXPANSION ROLL REPAIR WAS SELECTED AS THE BEST CONTINGENCY REPAIR APPROACH FOR THE FOLLOMING REASONS:

1

~

THE ROLL REPAIR ttAS KNOMN TO BE A STANDARD REPAIR TECHNIQUE HAVING FIELD EXPERIENCE IN THE POMER INDUSTRY AS MELL AS IN OTHER BMRs (BIG ROCK POINT,

NUCLENOR, OYSTER

CREEK, AND GARIGL!ANO) 2, EXPERIENCE INDICATED THE REPAIR TO POSSIBLY BE A

LONG-TERM F I X, 3.

~ THE REPAIR COUlD BE ACCOMPLISHED QUICKLY MITH MINIMAL TOOL/PROCEDURAL DEVELOP MENT.

OTHER REPAIR APPROACHES MOULD REQUIRE SIGNIFICANT DEVELOP MENT.

5.

ROLL REPAIR HAD P REV I OUSL Y BEEN AP P ROVED BY THE NRC FOR BWR REACTOR VESSELS.

SAFETY EVALUATIONS OF THE ROLL REPAIR APPROACH INDICATED THAT PREVIOUS SAFETY IMPLICATIONS MERE NOT AFFECTED AND THAT ROLL I NG P ROV I DES ADDI T I ONAL HOUS I NG S UP P ORT

.304SS Weld 1.12 to 4.93" 304SS Stub Tub@

(Furnace Sensitized) 304SS Cladding 1/20 3H Rolled Location

$ /2N 304SS CRD Mous<,ng Alloy Carbon Steel Vessel ROLLED AREA OF NMP-I CRD HOUSING

0 e

Leak Test Connec 'on

5. 25 Rolled Area Type A

Mock-Up 4

3/S Rol ed Area

.ype 9

Nock-Up MGCK-UPS

t

NSPE T

ONS AN R

PA RS TO R

PENETRAT ONS IN SPRIN OUTA E NSPE TIONS ML FOLLOMING VESSEL SHUTDOMN IN (QPLGIONS

NARCH, 1984, YISUAL INSPECTIONS MADE ON OUTSIDE BOTTOM HEAD AT ALL PENETRATIONS 2 PENETRATIONS MITH EVIDENCE OF

LEAKAGE, ONE LEAKING SEVERAL DROPS 'P ER MINUTE, ONE MITH DAMPNESS.

7 SUSPECTED OF PRIOR LEAKAGE BASED ON OUTSIDE INSPECTIONS, 12 HOUS INGS INSPECTED INSIDE MITH TV.

CRACKS FOUND IN 6 STUB TUBES

~

ULTRASON I C I NSPE CT I ONS 2.,

ROLL REPAIRS INSPECTED FROM ID OF HOUSING TO INSURE INTEGRITY OF HOUSING AiND J-MELD.

I NSPECTED ALl HOUS I NGS THAT MERE ROLLED (PRIOR TO AND AFTER ROLL IN 6),

NO I ND I CAT I ONS FOUND.

DURING OUTAGE -

ROLLED 9 PENETRATIONS:

2 SHOMING EVIDFNCE OF LEAKAGE 7

SUSPECTED OF PRIOR LEAKAGE POST OUTAGE REPAIR A TENTH HOUSING MAS ROLLED AFTER INITIAL COLD HYDROSTATIC TEST REVEALED LEAKAGE AT 6 DP M

INSPECTION RESULTS FROM SPRING I 984 OUTAGE 51 47 39 35 31 27 23 19 15 07 03 02 06 10 14 18 22 26 30 34 38 42 46 50

.Legend:

Inspected By CCTV Possible Evidence Of Prior Leak

'isible Leak

. Crack Visible By CCTV

. ~

ONT IN EN P

ANS AND NVEST AT ONS TO PREPARE FOR SP R I N OUTA E 1

~

DEVELOPMENT OF ROLL REPAIR IMPROVEMENTS PROCUREMENT OF IMPROVED ROLLING EQUIPMENT, NOCK-UPS MOCK-UP TESTS OF METHODS FOR ROLLING ABOVE AND BELOM PREVIOUSLY ROLl ED HOUSINGS JUSTIFICATION FOR SECURING COOLING ADDITIONAL VERIF I CATION OF ACCEPTABILITY OF ROLLING PROCESS EPRI METALLURGICAL/MGCL2 TESTS 2.

DEVELOPMENT OF IN-SERVICE INSPECTION PROGRAM FOR CONTROL ROD DRIVE PENETRAT IONS.

(SUBMITTED TO NRC 10/Ol/80) 3.

DEVELOPMENT OF GUI DEL I MES FOR REPAIR OF LEAKIiNG CRD PENETRATIONS, (PRESENTED TO iNRC 11/18/85)

RO REPA R

PROVEMENTS ADDITIONAL MOCK-UP TESTS ROLLIN TEST ABOVE AND BELO ORI NA RO CONSISTED OF ROLLING TMO ADDITIONAL EXPANSION ROLLS ON A PREVIOUSLY ROLLED HOUSING, THE PURPOSE OF THIS TEST MAS TO QUALIFY ROLLING PROCEDURES/PERSONNEL/TOOL ING FOR REPAIR OF PREVIOUSLY ROLLED HOUSINGS FOUND TO BE LEAKING, ADDITIONAL ROLLING TESTS PERFORMED, ON FULL SCALE MOCK-UPS.

CONCLUDED ROLl ING ABOVE AND BELOW IS EFFECTIVE AND INTRODUCES NO HARMFUL EFFECTS, PROCEDURES MERE DEVELOPED FOR SPRING 1986 OUTAGE.

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304SS Stub Tube (Furnace Sensitized) 304SS Cladding Znconel Weld Additional Rolled Locations V al I

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I I

3N Rolled Location 1/2" I

I I

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304SS CRD Housing Alloy Carbon Steel Vessel NMP-1 CRD HOUSING ADDITIONALROLLED AREA

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EVMUAT ONS TO D T R

E-EFFE TS OF SE UR N

00 N

F 0

TO DR VES HOUSING/VESSEL MINIMUM CONTACT PRESSURE FROM ROLLING (FOR NORMAL OPERATING CONDITION) IS:

MITH COO! ING FLOM TO CRD HOUSING:

PRESSURE IS 0200 PsIA MITH NO COOLING FLO'A:

PRESSURE IS 7400 PsIA SAFETY EVALUATION BY GE CONFIRMS ACCEPTABILITY OF SECURING COOLING FLOM TO DRIVES.

MINIMA EFFECT ON:

LIFETIME OF NON-METALLICS (MAINTENANCE SCHEDULE IS INCREASED TO EVERY RE-FUEL CYClE)

TECH SPEC LIMITS (S CRAM TIME)

CURRENTLY PREPARING NECESSARY PLANT-SPECIFIC SAFETY EVALUATIONS AND PROCEDURES TO ALLO'A SECURING OF COOLING TO SPECIF I C DRIVES

4

0 0

VER F AT ON OF A

EPTAB T

OF RO IN P ROCESS EVALUATIONS MERE CONPLETED PRIOR TO SPRING 1980 OUTAGE TO DETERMINE COI D MORK EFFECTS ON IGSCC RESISTANCE IGSCC RESISTANCE MAS FOUND TO BE UNAFFECTED BASED ON SERVICE EXPERIENCE AND CORRELATIONS USING HARDNESS LEVELS CONFIRMATORY INVESTIGATIONS MERE STARTED AT EPRI-CHARLOTTE TO STUDY:

LOCATION OF STRAIN-INDUCED NRTENSITE.(NARTENSITE CAN SENSITIZE AT REACTOR TENPERATURE)

RESIDUAL STRESSES TESTS MERE COMPLETED PRIOR TO SPRING 1986 OUTAGE AND SHOMED:

NRTENSITE IS PRESENT BUT ONLY IN ROLLED REGIONS OF HOUS I NG I, D.

NET STRESSES IN ROl LED REGION ARE COMPRESSIVE AND ARREST ANY CRACKING RQLLliNG DOES iNOT AFFECT IGSCC RESISTANCE OF ROLLED HOUS I iNG

~ r!

0 NSPE T

ON PLAN FOR RD PENETRAT ONS INSERVICE INSPECTION PROGRAM FOR CRD PENETRATIONS SUBMITTED TO NRC ON 10/01/80 VISUAL INSPECTION FOR LEAKAGE DURING HYDROSTATIC TESTS AT REFUEL OUTAGES UT AT LEAST TMO PREVIOUSLY ROLLED HOUSINGS CLOSE CIRCUIT TV INSPECTION OF STUB TUBE CRACKING IF CELL IS DISASSEMBLED

4

.0 U

EL INES FOR REPA R

OF EA N

PENETRAT ONS GUIDELINES FOR I)MPLEMENTING REPAIR STEPS.

FOR LEAKING CRD PENETRATIONS MERE DEVELOPED FOR THE SPRI)NG 198S OUTAGE AS FOLLOWS:

REPAI'R ROLL REPAIR ADDITI ONAL ROLLS OF PREVIOUSLY ROLLED HOUSING CONTINGENCY REPAIRS FOR ROLLED HOUSING LEAKAGE L IMIT FOR I MPLEMENTI NG R

PA R

STEPS NOT CLEAR EV I DENCE OF LEAKAGE LEAKAGE RATE ~

15 DROP/MIN AT HYDRO PRESSURE LEAKAGE RATE ~ 0.1 GPM AT HYDRO PRESSURE 0

GUI DEL I ilES PRESENTED TO THE NRC FOR REV IEM AND SUBMITTED TO

)NRC FOR APPROVAL NOTE":

INSPECTIONS AND REPAIRS TO BE PERFORMED AT HYDROSTATI C TEST BUR I iNG REF UEL OUTAGE S

~

~

~

~

~ 0

~

J

YELOP ENT OF RO REPA R

FOR SPR N

OTAE ROLLING PROCEDURES AND EQUIPMENT MERE QUALIFIED AND PERSONNEL MERE TRA I NED ON 10 FULL SCALE MOCK-UP ASSEMBLIES.

LEAK TESTS MERE PERFORMED ON MOCK-UPS BEFORE AND AFTER S I MULATED REACTOR HEAT-UP AND COOL-DOMN CYCLE.

DIMENSIONAL, YISUAL, AND HARDNESS TESTS MERE MADE MHICH CONFIRMED THE ACCEPTABILITY OF THE REPAIR

0

~

RITER A FOR NSERV LEA A E NMPC MILL MONITOR ANY INSERVICE CRD PENETRATION LEAKAGE BY MEANS OF THE EXISTING DRYMELL UNIDENTIFIED LEAKAGE MONITORING SYSTEM NMPC MILL INSPECT FOR CRD PENETRATION LEAKAGE DURING NON-REFUEL OUTAGES MHERE ACCESS TO THE DRYMELL IS AVAILABLEAND MILL EVALUATE RESULTS ON A CASE BASIS.

MEASURED CRD PENETRATION LEAKAGE UP TO 0.1 GPM PER PENETRATION, OR 1

GPM TOTAL, AT 900 1000 PSI MILL BE CONSIDERED ACCEPTABLE FOR CONTINUED OPERATION.

~

NSP T

ONS AN PA RS TO R

PENETRAT ONS D

N SP IN OUTA E NSr E T

ONS V IS UAI INSPECTIONS LTRASON I C HSP E CT I ONS 2,

REPAIRS ROLL REPAIRS DURING OUTAGE POST-OUT,AGE REPAIR

-'DDITIONAL LEAKS FOLLOWING PLANT SHUTDOWN IN MARCH,

1986, V ISUALLY INSPECTED OUTS I DE

'OTTOM HEAD AT ALL CRD PENETRA-

TIONS, FOUND TWO HOUS INGS LEAKING SEVERAL DROPS PER MINUTE.

ONE HOUSING HAD NOT BEEN PREVIOUSLY

ROLLED, ONE HOUSING HAD BEEN PREVIOUSLY ROLLED.

INSPECTED 0

HOUSINGS DURING '86 OUTAGE TO ENSURE INTEGRITY, INSPECTED ONE HOUSING ROLLED IN

'80 OUTAGE INSPECTED 2

HOUS INGS PRIOR TO AND AFTER RE-ROLL ING',

INSPECTED ONE HOUSING PRIOR TO AND AFTER ROLLING, BASED ON VISUAL INSPECTIONS UNDER VESSEL

HEAD, ROLLED 1

HOUSING AND RE-,ROLLED 1

HOUS I NG A SECOND HOUSING

'FANS RE-ROLLED AFTER INITIAL COLD HYDROSTATIC TEST REVEALED LEAKAGE AT 0

TO 6

DPN, DURING RECENT PLANT RE-START (SHUTDOWN FOR -EQUIPMENT REPAIRS),

PENETRATION 06-27, ORIGINALLY ROLLED IN '80 WAS FOUND TO BE LEAKING AT 0

TO 6 DPM.

PLANT IN STARTUP MODE.

NO REPAIRS

MADE,

E, RE ENT REPA Rl URRENT STATUS l.

DURING RECENT MAINTENANCE OUTAGE DURING THE MEEK OF AUGUST 8,

1986, NMPC FOUND EVIDENCE OF A LEAKING PENETRATION, NO 34-19, LEAKING AT ABOUT 120 DPM AS ESTIMATED FROM CRD FLANGE,"

2 PENETRATION NO. 34-19 SUCCESSFULL'Y ROLl REPAIRED, (4 1/2" ROLL BAND) 3.

NO LEAKAGE FROM NO, 34-19 FOLLOMING INSPECTION

~

DURING IN-SERY I CE START-UP.

PENETRATION NO.

46-27 NOTED TO STILL BE LEAKING ABOUT 4

TO 6 DPM DURING IN-SERVICE INSPECTION.

(LEAKAGE LESS THAN 15'DPM PER GUIDELINES)

"INSPECTIONS OF PENETRATION NO. 46-27 SHOMED NO LEAKAGE AT THIS TIME,

4I i,n j

l t,

ROLL REPAIR

SUMMARY

Found Leaking (About 120, DPM)

During Maintenance Outage.

Roll Repaired Week Of 8/4/86 (No.Subsequent Leakage)

Evidence Of Leakage At 4 To 6

DPM During Recent Plant Restart 51 4,7 43 39 35 27 23 19 15 07, 03 Legend:

02 06 10 14 18 22 26 30 Visually Inspected In 1984 From Inside Vessel Roll Repaired 10 Housings In 1984 Roll Repaired 1 Housing In 1986 Rolled Two Additional Rolls On 2 Housings In 1986 34 38 42 46 50 Rolled After Post Pepair Hydrostatic Test In 1984 Rolled Two Additional Rolls After Post Repair

~

Hydrostatic Test In 1986

ODE OMPL IAN AND L ENS N

BAS IS FOR R PA R

APPROA H

1 ASME CODE. COMPLIANCE STUB TUBE PENETRATIONS ARE ATTACHED WITH NON-FULL PENETRATION WELDS DESIGNED TO:

HOLD CRD HOUSINGS FROM EJECTION P ROV I DE A

P RESS URE BOUNDARY SEAL THE STUB TUBE-TO-VESSEL

WELD, HOUS ING-TO-STUB TUBE WELD, AND STUB TUBE ARE NOT PART OF.

VESSEL RE INFORCEMENT AREA.

ALL RE INFORCEMENT IS INTEGRAL WITH VESSEL

WALL, REPAIR TO CRD PENETRATIONS BY ROLLING BASED ON REQUIREMENTS OF SECTION XI, PARAGRAPH I WB-3102. 9.

COMPONENTS CONTAINING RELEVANT CONDITIONS SHALL BE ACCEPTABLE FOR CONTINUED SERVICE IF AN ANALYTI CAL EYALUATI ON DEMONSTRATES THE COMPONENTS ACCEPTAB ILITY,"

EVALUATIONS COMPLETED (AS DISCUSSED ABOVE)

WHICH INCLUDE:-

SAFETY EVALUATIONS MOCK-UP TESTS REVIEWS OF IN-SERV I CE EVALUATIONS AT OTHER BWRs ANALYT I CAL EVALUATI ONS CON CL UDED REP A I R STAT US WAS AC CEP TABLE

IN, ACCORDANCE MITH CODE RFQUIREMENTS, ACCEPTANCE CRITERIA DEVELOPED IN FORM O" LEAKAGE LIMITS.

PROPOSE USE OF THESE LIMITS FOR REPAIR BASIS DURING RE-FUEL OUTAGES NRC SAFETY EVALUATIONS COMPLETED FOR NMP-I (SER DOCKET 50-220, DATED 06/29/84)

AND OTHER BMRs CONCURRED IN ACCEPTABILITY OF ROLL REPA I R 'METHOD INB-3144 REQUIRES EVALUATION ANALYSIS AND RE-EXAMINATION RESULTS BE SUBMITTED TO THE REGULATORY AUTHOR IT Y

4

ENS N

BAS S

THE FIELDED PENETRATION MITH A ROLLED JOINT

-MAINTAINS (OR IMPROVES)

THE ORIGINAL STRUCTURAL INTEGRITY OF THE VESSEL PENETRATIONS THE REPAIR PROCESS CHANGES THE PRIMARY SEAL FROM A MELDED TO A MECHANICAL SEAL, LIMITED LEAKAGE IS NOT ABNORMAL FOR THIS TYPE SEAL.

CONCLUDE THAT LICENSING BASIS REMAINS AS SPE'CIFIED IN GDC 10, TO HAVE AN EXTREME Y LOM PROBABILITY OF ABNORMAL LEAKAGE, OF RAP IDLY PROP OGAT I NG FAILURE, AND OF GROSS RUPTURE,"

HAS BEEN APPROVED BY, NRC PREY IOUSLY FOR NMP-1, BIG ROCK POIiNT, AiND OTHERS.

ANY LEAKAGE DURING OPERATION MILL BE GOVERNED BY TECH SPEC UNIDEiNTIFIED LEAKAGE LIMITS TOTAL l EAKAGE DURING HYDRO TESTS NILI BE LIMITED TO 1.0 GPM FROM ALL PENETRATIONS

.III.

BAC -UP E

HAN A

SEAL DEVE OP ENT PRO RA A.

P URP OSE MAINTAIN LEAKAGE LIMITS DUE TO POSSIBLE RELAXATION OF ROLLED JOINTS POOR ROLLED JOINT INITIAL SEAL (POOR SURFACE CONDITIONS, STEAM CUTTING)

B, CE SEAL DEVELOPMENT FABRICATE PROTOTYPE SEAL FOR DESIGiN PRESSURE TESTS TEST SCHEDULED FOR EARLY 1987 C ~

MP R ME CHAN I CAL SEAL DEVELOP MENT SEAL DESIGN PROTOTYPE FABRICATION o

SEAL TESTING DEVELOPMENT OF REMOTE MACHINING CAPABILITY DES IGiN AND FABRI CATION OF PROTOTYPE INSTALLATION TOOLING CONTINGEiNCY PLANNING FOR IMPLEi1EilTATION PHASE

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cuba ~ouaiuc, NMP-I PROTOTYPE MECHANICAL SFAL ASSa.MQLY

FEATURES OF MPR MECHANI AL SEAL CONVENTIONAL PACKING SEAL, AXISYMMETRIC GEOMETRY, GOOD SEAL SURFACES, PRESSURE SEATED HIGH CONFIDENCE OF SUCCESS PROVIDES POSITIVE RETENTION.OF CRD HOUSING, IN ADDITION TO ROLLED JOINT REMOTELY INSTALLABLE WITHOUT WELDING AND WITHOUT DRAINING VESSEL DOES NOT AFFECT VESSEL PRESSURE RATING COMPL-IES WITH ASME'CODE, SECTION XI IS REMOVABLE FOR SEAL REPLACEMENT, IF EVER REQUIRED

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ODE AND L ENS N

BASES FOR HAN L.SEA COMPLIANCE WITH ASME SECTION III PROYIDED BASED ON FOLLOWING:

1, MECHANICAL SEAL WOULD PROVIDE DESIGN FUNCTIONS OF THE WELDED AND ROLLED EXP ANS ION PENETRATION PROVIDE POSITIVE RETENTION OF HOUSING AGAINST EJECTION PROVIDE A PRESSURE BOUNDARY SEAL TO LIMIT LEAKaGE 2

THE SEAL WOULD NOT BE CONSIDERED AS YESSFL REINFORCEMENT MATERIAL 3.

THE MECHANICAL SEAL WOULD BE CLASSIFIED AND DESIGNED AS A SPECIAL PIPING JOINT IN ACCORDANCE WITH ASME

CODE, SECTION III, SUB-SECT I ON NB-3671,7 MECHANICAL JOINTS, FOR WHICH NO STANDARDS EXIST, AiRD OTHER PATENTED JO'INTS MAY BE USED PROYIDED THE REQUIREMENTS.

OF A, B, AND C BELOW ARE MET PROYISION IS MADE TO PREVENT SEPARATION OF THE JOINT UNDER Al L SERY I CE LOADI NGS THEY ARE ACCESSIBl E FOR MAINTENANCE, REMOVAL,'ND REPLACEMEiNT AFTER SERVICE.

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EITHER OF THE FOLLOWING TWO CRITERIA ARE MET:

1,)

A PROTOTYPE JOINT HAS BEEN SUBJECTED TO PERFORMANCE TESTS...

2.)

JOINTS ARE DESIGNED IN ACCORDANCE WITH THE RULES OF NB-5200 THE ALTERNATIYE MECHANICAL SEAL ASSEMBLY BEING CONSIDERED FOR NMP-I MEETS THESE REQUIREMENTS

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STATUS OF PR BA

-UP SEA DEVE OP ENT 1,

PROTOTYPE SEAL HAS BEEN DESIGNED, FABRICATED AND TESTED.

FABRICATED ITEMS:

PROTOTYPE SEAL SEAL TEST FIXTURE FOR PRESSURE TESTS 2

TESTS ON SEAl INCLUDE:

AMBIENT TEMPERATURE TESTS AT PRESSURES UP TO 1500 PSI AMBIENT TEMPERATURE TESTS MITH PRESSURE CYCLES BETWEEN 1000 AND 100 PSI.

NO LEAKAGE FROM SEAL MAS OBSERYED DURING TESTING PERIODS UP TO 30 MI)VUTES, 3.

CRD/STUB TUBE MACHINING-FEASIB ILITY DEMONSTRATION MORK STARTED,:.

MECHAN I CAL MACH I iV I NG--P C I EDM P ROP OSALS BEING EVALUATED INSTALLATI ON TOOL I NG.BE IiVG DES I GiVED EST I MATED T I )ME FOR COMP LETI ON OF SEAL AND TOOL I )VG FEAS IBILITY STUDY8-10 MONTHS 1

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NMP-l PROTOTYPE MECllANICALSEAL ASSEiv)BLY TEST FlXTURE

IV.

TR P

ANS FOR RPA P ORA 1

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CONTINUE TO IMPLEMENT GUIDELINES FOR REPAIR OF LEAKIN6 PENETRAT IONS.

2.

CONTINUING MITH PROCEDURES/EVALUATIONS TO SECURE CRD HOUSIN6 COOLING FLOQ IF REAUIRED TO REDUCE-

LEAKA6E, CURRENT INTEREST TO SECURE COOL I N6 TO

. 06-27.

CONTINUIN6 NITH NORK TO CONF.IRM OPTIMIZATION OF ROL'LING PROCEDURES PULL TESTS OF CRD HOUSING MOCK-UPS ELAST I C/PLASTI C MODEL I NG EVALUATI ONS CONTINUING MITH DEVELOPMENT OF BACK-UP SEAL STUB TUBE/HOUS I NG MACHINING MECHANICAL CUTTING EDM SEAL TESTIN6 HANDLING TOOL DEVELOPMENT CONTINGENCY PLANS UNDER DEVELOPMENT FOR IMPLEMENTATION OF BACK-UP SEAL FABRICATION OF PRODUCT-ION, FULL HEIGHT MACHINING AND I NSTALLATI ON TOOLS QUALIFICATION OF PROCEDURES AND EOUIPMENT

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$ ITE SUPPORT 0

LICENSINS SOPPORT ESTIMATED TINE TO PREPARE FOR SEAL INSTALLATION AFTER DECISION -TO INPLENENT BACK-UP PLAN--20-50 NONTHS

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Distribution for Meetin Summary Dated:

Facility:

Nine Mile Point Nuclear Station*, Unit No.

1 Docket File (50-220)

NRC PDR Local PDR BWDl Reading R. Bernero/R.

Houston J. Zwolinski J. Kelly C. Jamerson OGC-BETH (Info only)

E. Jordan B. Grimes ACRS (10)

D. Vassallo G. Lainas/R.

D. Liaw R. Hermann G. Thomas H. Conrad H.

Shaw W. Hazelton Y-Li Li P. Cortland Nine Mile file

• Copies sent to persons on facility service list

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