ML20212J387

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Summary of 861103 Meeting W/Util,Westinghouse & O'Donnell & Assoc,Inc Re Possible Use of Pipe Locks to Repair IGSCC at Facility.List of Attendees & Slide Presentation Encl
ML20212J387
Person / Time
Site: Brunswick  Duke Energy icon.png
Issue date: 01/21/1987
From: Sylvester E
Office of Nuclear Reactor Regulation
To:
Office of Nuclear Reactor Regulation
References
NUDOCS 8701280187
Download: ML20212J387 (11)


Text

o Docket Nos. 50-325/324 LICENSEE: Carolina Power and Light Company (CP&L)

FACILITY: Brunswick Steam Electric Plant, Units 1 and 2

SUBJECT:

SUMMARY

OF MEETING HELD ON NOVEMBER 3,1986: PIPE REPAIR FOR INTERGRAhULAR STRESS CORROSION CRACKING (IGSCC)

Background

Discussions were held with CP&L and its contractors on November 3, 1986 regarding the possible use of pipe locks to repair welded joints at Brunswick 1 and 2. The list of attendees is provided in Enclosure 1.

Brunswick I will be shutdown for a maintenance and refueling outage on February 13, 1987. During that outage, inspections will be performed to determine the existence of intergranular stress corrosion cracking (IGSCC) in Inconel weld butter in reactor coolant system pipe welds. Brunswick 2 is currently operating in Fuel Cycle 7 with unrepaired cracks in two nozzel-to-safe-end welds. Approval for continued operation for the duration of Fuel Cycle 7 was granted by the NRC in a letter dated October 5, 1986. Brunswick 2 reactor coolant system pipe welds will be re-examined at the end of Fuel Cycle 7.

CP&L is considering the use of pipe locks as a possible method of pipe repair in the event that unacceptable crack indicaticns are identified in Inconel butter joints in the Unit I and 2 IGSCC inspections. Consequently, CP&L requested that a meeting be held with the NRC staff to identify NRC concerns with the use of pipe locks and the information that would be required in a submittal to obtain NRC approval for the use of pipe locks.

Meeting Summary Some background information on the design and use of pipe locks at other nuclear power facilities was presented by Mr. William O'Donnel of 0'Donnell &

Associates, Inc. (0DAI), a CP&L contractor. ODAI is the developer of pipe locks and patent-holder for the design. CP&L stated the position that pipe locks are superior to weld overlay repair and are thus an acceptable long-term repair method for reactor coolant piping susceptible to IGSCC. One benefit accruir.g from the use of pipe locks relative to weld overlays is that pipe lock installation does not preclude future inspection of the original weld.

Copies of the slides used in the CP&L presentation are provided as Enclosure 2.

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The use of pipe locks at other nuclear power facilities has-been done on a trial basis in areas where NRC approval was not required. That is, pipe locks have been used in conjunction with weld overlay where the weld overlay was the primary method of pipe repair and satisfied NRC criteria. NRC approval has not been granted for the use of pipe locks as the sole method of pipe repair at any facility. The current position of the NRC staff is that pipe locks are not an ASME-prescribed repair method for pipes but could be approved as an acceptable alternate to weld overlay repair if adequate justification is provided.

CP&L committed to provide justification for a representative use of pipe locks at the Brunswick facility prior to the start of the Unit I refueling outage, i.e. , before February 13, 1987. Additional information on the specific installations used at Brunswick 1 (if any) will be provided along with a request for approval to restart prior to startup from the outage in June 1987.

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%w 'c.'c,;:1,!.c Ernest D. Sylvester, Project Manager BWR Project Directorate #2 Division of BWR Licensing

Enclosures:

As stated cc: See next page DISTRIBUTION Docket file; 4 NRC PDR Local PDR PD#2 Memo DRMuller ESylvester 0GC-Bethesda EJordan BGrimes ACRS (10)

NRC Participants DBL:PD#2 D%: 2 ESylyester/cd DRM 1 r 1/ W /87 1/LJ /87 0FFICIAL RECORD COPY

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Mr. E. E. Utley Brunswick Steam Electric Plant Carolina Power & Light Company Units 1 and 2 cc:

Mr. P. W. Howe , Mr. C. R. Dietz Vice President Plant General Manager Brunswick Nuclear Project Brunswick Nuclear Project Box 10429 Box 10429 Southport, North Carolina 28461 Southport, North Carolina 28461 Thomas A. Baxter, Esquire Mr. H. A. Cole Shaw, Pittman, Potts & Trowbridge Special Deputy Attorney General 2300 N Street, N. W. State of North Carolina Washington, D. C. 20037 Post Office Box 629 Raleigh, North Carolina 27602 Mr. D. E. Hollar Associate General Counsel Mr. Robert P. Gruber Carolina Power & Light Company Executive Director Post Office Box 1551 Public Staff - NCUC Raleigh, North Carolina 27602 Post Office Box 29b20 Raleigh, North Carolina 27626-0b20 Mr. Christopher Chappell, Chairman Board of Commissioners Post Office Box 249

, Bolivia, North Carolina 28422 Mrs. Chrys Baggett State Clearinghouse Budget and Management 116 West Jones Street Raleigh, North Carolina 27603 Resident Inspector U. S. Nuclear Regulatory Comission Star Route 1 Post Office Box 208 Southport, North Carolina 28461 Regional Administrator, Region II U. S. Nuclear Regulatory Comission 101 Marietta Street, Suite 2900 Atlanta, Georgia 30303 Mr. Dayne H. Brown, Chief Radiation Protection Branch Division of Facility Services -

N. C. Department of Human Resources 701 Barbour Drive Raleigh, North Carolina 27603-2008

ENCLOSURE 1 MEETING ATTENDEES NRC CP&L R. Hermann S. Zimmerman W. Hazelton S. Floyd R. Bosnak ,. B. Mann W. Koo J. Titrington Y. Li C. Patterson R. Johnson E. Sylvester O'Donnell & Associates, Inc. Westinghouse W. O'Donnell' J.~ Dougherty J. Porowski E. Krch E. Hampton Westinghouse - Innovative Technologies Inc.

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ENCLOSURE 2 CAROLINA POWER AND LIGHT COMPANY BRUNSWICK STEAM ELECTRIC PLANT APPLICATION OF PIPELOCK ON FLAWED INCONEL BUTTER WELDS NOVEMBER 3, 1986 e

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PRESENTATIONS OUTLIRE-I. INTRODUCTION- ,

CHRIS PATTERSON (CP&L)

II. LICENSING APPROACH CHRIS PATTERSON (CP&L)-

III..PIPELOCK. SOLUTION BILL O'DONNELL (0DAI)

ED HAMPTON (ODAI)-

t IV, INSPECTABILITY- BRIAN MANN (CP&L)

V.

SUMMARY

/ CONCLUSIONS CHRIS PATTERSON (CP&L)

! JOHN TITRINGTON (CP&L)  ;

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INTRODUCTION o BRUNSWICK UNITS ARE. SUSCEPTIBLE TO INCONEL BUTTER CRACKING TWO SMALL INDICATIONS ON UNIT 2 PLAN TO REINSPECT UNIT 1 o MUST DEVELOP REPAIR FOR UNIT 2 INDICATIONS AND CONTINGENCY

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REPAIR PLAN FOR UNIT 1 o CP&L DECISION ANALYSIS IDENTIFIES PIPELOCK AS AN ACCEPTABLE SOLUTION FOR THE BRUNSWICK UNITS

_o CP&L NEEDS NRC INPUT:

1. CONCURRENCE WITH CONCEPT
2. CONTENT OF SUBMITTAL 3, SCHEDULE ACCEPTABILITY CP&L REQUESTS NRC CONCURRENCE WITH THE PIPELOCK CONCEPT AND  !

LICENSING APPROACH FOR APPLICATION ON THE BRUNSUICK UNITS, i

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LICENSING APPROACH o PRESENT PIPELOCK SOLUTION NOVEMBER 3, 1986 r o IDENTIFY NRC CONCERNS WITH THIS SOLUTION NOVEMBER 3, 1986 h o OBTAIN NRC INPUT FOR SUBMITTAL NOVEMBER 3, 1986 o SUBMIT COMPLETE LICENSING PACKAGE FOR REPRESENTATIVE RPV N0ZZLE TO SAFE-END PIPELOCK FOR APPROVAL PRIOR TO THE START OF THE UNIT 1 RF5 0UTAGE JANUARY 1987 o SUBMITTAL WILL CONTAIN:

1. ASME CODE DESIGN ANALYSIS l
2. TEST VERIFICATION PROGRAM o SUBMIT COMPLETED LICENSING PACKAGES FOR SPECIFIC RPV N0ZZLE TO SAFE-END PIPELOCK INSTALLATIONS PRIOR TO UNIT 1 RF5 0UTAGE STARTUP o INSTALLATION TO START AS EARLY AS MARCH 1987

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INSPECTABILITY O

THE PIPELOCK ITSELF CAN BE EXAMINED PER ASME XI REQUIREMENTS.AS AN ADDED MEASURE OF CONSERVATISM THE PIPELOCK IS DESIGNED FOR OPTIMUM INSPECTABILITY OF THE ORIGINAL WELD, 0 THE PIPELOCK, WHEN REMOVED, WILL NOT INTERFERE WITH UT --

EXAMINATION TECHNIQUES RECOMMENDED BY EPRI/BWROG, IGSCC RESEARCH PROJECT T-301-2, DEVELOPMENT OF IMPROVED PROCEDURE FOR EXAMINATION OF DISSIMILAR METAL WELDS IN BWR N0ZZLE-TO-SAFE-END WELD.

O THE GROOVES THAT-ENABLE THE PIPELOCK TO ADEQUATELY GRIP THE PIPE ARE DESIGNED TO ALLOW EXAMINATION TO THE WELD ROOT WITH A 60 TRANSDUCER.

O THE SURFACE FINISH, WHICH IS EXTREMELY CRITICAL TO IGSCC DETECTION AND SIZING, WILL REMAIN MACHINED IN THE AREA 0F INTEREST.

O THE ABILITY TO EXAMINE WITH THE USE OF AUTOMATED UT IS UNAFFECTED.

l O THE ABILITY TO EXAMINE-THE SAFE-END, THERMAL SLEEVE CREVICE AREA, AND SURROUNDING WELDS WILL BE UNAFFECTED.

THE PIPELOCK WILL ALLOW ACCEPTABLE EXAMINATION BY UT FOR DETECTION, SIZING, AND MONITORING OF IGSCC INDICATIONS.

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esmemame PIPELOCK SOLUTION k

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m go CONCLUSION o PIPELOCK MEETS ASME SECTION III CLASS I CODE.AND REGULATORY REQUIREMENTS; NO REDUCTION IN MARGIN -

o PIPELOCK INDUCES COMPRESSIVE STRESS IN PIPE WALL TO STOP CRACK GROWTH o PIPELOCK INTEGRITY IS EASILY VERIFIED o INSPECTION OF WELD JOINTS IS DOSSIBLE, BUT NOT NECESSARY FOR SAFETY PIPELOCK IS AN ACCEPTABLE REPAIR FOR INCONEL BUTTER JOINTS