ML20094P429

Discusses SG Sleeving,Per NRC Issuance of Amends 72 & 63 to Licenses NPF-2 & NPF-3,respectively.Amends Authorized Use of Mechanical Hybrid Expansion Joint Sleeve for Repair of SG Tubes,Per WCAP-11178,Rev 1

ML20094P429
Person / Time
Site:	Farley
Issue date:	04/02/1992
From:	Woodard J SOUTHERN NUCLEAR OPERATING CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
NUDOCS 9204080127
Download: ML20094P429 (2)

Text

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u t o . .o,,, Southern Ntalcar Operatirig Cot 11pativ

[NEN April 2,1992

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Docket Nos. 50-348 50-364 U.S. Nuclear Regulatory Cownission A11N: Document Control Desk Washington, D.C. 20555 Joseph M. farley Nuclear Plant Sinm Censnior Slecying__

Gentlemen:

By letter dated September 18, 1987, the Nuclear Regulatory Conunission issued Amendment No. 72 to facility Operating License No. NPf-2 and Amendment No. 63 to NPT-8 f or the Joseph M. F arley Nuclear Plant, Units 1 and 2. These amendments authorized the use of a mechanical, hybrid expansion joint (HEJ) sleeve for the repair of steam generator tubes per WCAP-lll78 Revision 1.

By letter dated October 22, 1990, the Nuclear Regul , tory Connission issued Amendment No. 85 to facility Operating License No. NPf-2 and Amendment No. 78 to facility Operating License No. NPf-8 for the Joseph M. farley Nuclear Plant, Units 1 and 2. These amendments authorized the use of a laser welded sleeve for the repair of steam generator tubes per WCAP-12672. WCAP-12672, " Steam Generator Sleeving Report, laser Welded Sleeves," contains a specific statement concerning the location of the laser weld for the lower joint of a full length tubesheet laser welded sleeve. On page 3-4, the WCAP states, "A single pass weld is then made between the sleeve and tube apprcximately 1 inch above the tubesheet cladding." The ASME Code imposes temperature exposure limits on the carbon steel tubeshaet material. While the calculated and measured temperatures on the steam generator tube outer diameter surface during welding will be below the l tubesheet critical temperature, additional assurance that the I tubesheet will not be exposed to unacceptable temperature excursions can be gained by placing the weld in the plane of the tubosheet cladding.

l As a result, if a full length tubesheet sleeve is required in the Unit l 2 Eighth Refueling Outage or subsequent outages, it is Southern Nuclear Operating Company's (Southern Nuclear's) intent to use a laser welded upper joint as described in WCAP-12672 and a mechanical, HEJ joint as the lower joint as described in WCAP-lll78. Revision 1. Only sleeves made of thermally treated inconel 690 will be used as described in WCAP-12672 and WCAP-lll78, Revision 1. A laser seal weld may be installed below the lower HEJ joint, okooh$4g PDR ph fjj;

1 U. S. Nuclear Regulatory Commission Page two l

Westinghouse has evaluated the sleeve configuration as described above and determined the testing and design verification discussed in wraps 12672 and 11178, Revision 1. remain valid. The sleeve configurat ..:

has also been reviewed through the 10 CFR 50.59 process, it has been determined that the integrated sleeve configuration described is not a change in the Technical $pecifications based on two factors, first, i the upper and lower joint configurations have been approved by the NRC  ;

in WCAp-lll78. Revision 1. " Steam Generator Sleeving Report l (Mechanical Sleeves)," and WCAP-12672, " Steam Generator Sleeving i Report, laser Welded Sleeves," both of which are referenced in the

-lechnical Specifications. Second, the integrated sinevo is a combination of approved joints. Additionally, Westinghouse has documented in WCAP<13115. " Steam tenerator Sleeving integration Report," th6t no effects impact the NRC appioved joints as a result of  :

combining the two joints in a single sleeve. The configuration is  ;

also not an unreviewed safety question.

Concerning the laser seal weld, by letter dated October 9, 1990, the NRC Staf f approved ASME Code Case N-395 for the use of laser welding for installation of laser welded sleeves at farley Nuclear plant. 1he ASME Code Section XI, Article IWB-4110, indicates that the scope of ,

repair procedures are_*the rules and requirements for repair of the '

pressure retaining boundary for Class I components and their  ;

supports." The proposed seal weld is located outside the pressure <

retaining boundary since the llEJ joint provides the prest.ure retaining ,

boundary, furthermore, ASMr Code Article NCA-9000 Glossary, defines repair as "[t]he process of physically restoring a nonconformance to a  ;

condition such that an item complies with Code requirements." As such, the scal wold is not a " repair " as that word is used in the  :

Technical Specifications because it is not restoring a nonconformance.

The seal weld is, therefore, simply complementing the proposed '

integrated sleeve in a manner which is acceptable to the governing Code. ,

This discusstun is being provided for information regarding Southern Nuclear's interpretation of the steam generator Technical Specifications. If-there are any questions, please advise.

Respectfully, SOUTHERN NULLEAR JPERATING COMPANY i

h obk N(, 3 Woodard JDW/ REM: map d.1 cc: Mr. S. D. Ebneter Mr. S.1. llof fman Mr. G. F. Maxwell L

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