ML19327A159

Discusses Current Position on Need & Requirement for Steam Generator Mods.Westinghouse Committed to Program to Determine Particular Susceptibility of Row 1 Tubes to Cracking.Results Expected in Oct 1980

ML19327A159
Person / Time
Site:	McGuire, Mcguire
Issue date:	07/18/1980
From:	Youngblood B Office of Nuclear Reactor Regulation
To:	Parker W DUKE POWER CO.
References
NUDOCS 8008010210
Download: ML19327A159 (4)

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UNITED STATES j j

/ j NUCLE AR REGULATORY COMMISSION

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JUL t 3190 Docket Nos.:

50-369 and 50-370 Duke Power Company ATTN:

Mr. William 0. Parker, Jr.

Vice President - Steam Production P. 0. Box 33189 422 South Church Street Charlotte, North Carolina 28242

SUBJECT:

STEAM GENERATOR fl0DIFICATIONS (McGUIRE ttVCLEAR STATION, UNITS 1 AND 2)

Your letter of May 23. 1980, stated that no changes to the McGuire steam generator would be made until the outcome of the Westinghouse steam generator tube testing program. Our current position on the need and requirements for these modifications are discussed.below.

Inspection Ports For some forms of steam generator degradation which have occurred, eddy current te: ~ing and tube gauging alone are not sufficient to assess and monitor tube support plate degradation.

In order to perform adequa.'e assessment and monitor-ing of these areas, it is necessary to install inspection ports.

These corts should be installed just above the upper suoport plate and between the tubesheet and the lower support plate and in line with the tube lane. At the upper support plate level, at least one, inspection port is required which shall be large enough for visual observation of the tube lane.

Under the as low as reasonably achievable (ALARA) concept. NRC has been requesting that all possible steam generator modifications be made before the start of operations in order to minimize personnel exposure. Although installation prior to initial ooeration is oreferable, it was determined that the potential instal-lation exposure following the first cycle of operation is not significant enough to justify the delay of the initial start-up of the plant to permit the installation of inspection ports. However, since secondary side contamination will increase as the operating time increases, NRC requires that these ports be installed prior to start-up after the first refueling. Accordingly. in the event that the ports have not been installed in the McGuire steam generator before the license has been issued, the license of each unit will reflect this requirement.

Row 1 Steam Generator Tubes Experience has shown that the small bend radius of the Row 1 tubes in the steam generators of. Westinghouse design leads to early onset of cracking.

At the present time 'lRC is not requiring licensees to plug Row 1 tubes crior to start-uo 1

THIS DOCUMENT CONTAINS 8008010t N P00R QUAUTY PAGES

2 Mr. Willian 0. Parker, Jr. JUL i 31930 or ' issuance of a full power license. Westinghouse has committed (letter from

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i R. M. Anderson to R..H. Vollmer, May 12,1980)- to a orocram to determine the particular susceotibility of Row 1-tubes to cracking.

The orogram involves removing numerous tubes from the Trojan plant and subjecting them to non-

' destructive and destructive testing to identify the cause of the cracking and to develoo a field insoection ' method capable of detecting potential leaking tubes. The results.of this evaluation are exoected to be available in October 1980. He shall review the program results and decide at that time on the necessity to plug the Row 1 tubes.

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Sincerely, B. J. Youngblood, Chief Licensing Branch flo.1 Division of Licensing ccs:

See-next page

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5 Mr. Willian 0. Par ker, Jr.

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Vice Pr es t. dent, Steam Pr oduction i

Duke Power Company l

P. O. Box 2178 422 South Church Street 4

Charlotte, Nor th Carolina 28242 cc:

Mr. W. L. Porter Duke Power Company David Flesichaker, Esc.

P. 0.-Box 2178 1735 Eye Street. N. W.

422 South Church Street Suite 709 Charlotte, Nor th Carolina 28242 Washincton, D. C.

20006 l

Mr. R. S. Howard Richard P. Wilson, Eso.

i Power Systems Division Assistant Attorney General l

Westinghouse Electr ic Corporation State of South Carolina P. O. Box 355 2600 Bull Street Pittsburgh, Pennsylvania 15230 Columbia. Sou th Carolina 29201 t

Mr. E. J. Keith EDS Nuclear Incorporated 6

220 Montgomery Street San Francisco, California 941C4 Mr. J. E. Houghtaling NUS Corpor ation 2536 Countryside Boulevard Clear water, Flor ida 33515 Mr. Jesse L. Riley, President The Car olina Envir onmental Study Gr oup 854 Henley Place-Charlotte, North Carolina 28207 J. Michael McGarry, III, Esq.

Debevoise A Liberman 1200 Seventeenth Street, N. W.

Washington,-D. C.

20036 Rober t M. Lazo, Esq., Chairman Atomic Safety and Licensing Board U. S. Nuclear Pegulatory Commission Washington, D. C.

20555 Dr. Emmeth A. Luebke

' I Atonic Safety and Licensing Board U. S. Nuclear _ Regulatory Commission Washington, D. C.

20555 Dr. Cadet H. Hand, Jr.,' Director Bodega Marine Lab of California P.'0. Box 24 7 Bodega Bay, California 94923 4

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Mr.~ William 0. Parker, Jr.

cc: David Flesichaker, Esq.

i 1735 Eye Street, N. W.,

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Suite 709 Washington, D. C.-

20006 Richard P. Wilson, Esq.

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. Assistant Attor ney Gener al State of South Carolina 2600 Bull Street Columbia, South Carolina 29201 1

Office of Intergovernmental Relations 116 West Jones Street Raleigh, North Carolina 27603 County Manager of Pecklenburg County 720 East-Fourth Street Charlotte, Nor th Carolina 28202 U. S. Environmental Protection Agency ATTN:

EIS Coordinator Region IV Office 345 Courtland Street, N. W.

Atlanta, Georgia 30308 4

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