ML20009B010

Tech Spec Change Request 69,amending Licenses DPP-24 & DPR- 27,to Permit Repair of Degraded or Defective Steam Generator Tubes by Sleeving.Request Involves Class III Fee.Asme Code & Regulatory Requirements Table & Fee Encl

ML20009B010
Person / Time
Site:	Point Beach
Issue date:	07/02/1981
From:	Burstein S WISCONSIN ELECTRIC POWER CO.
To:	Harold Denton Office of Nuclear Reactor Regulation
Shared Package
ML20009B011	List: ML20009B010 ML20009B014
References
TAC-46694, TAC-46695, NUDOCS 8107140651
Download: ML20009B010 (4)

Text

V Wisconsin Electnc eaara cournr 231 W. MICHIGAN, P.o. BOX 2046 MILWAUKEE, WI 53201 July 2, 1981 Mr. Harold R. Denton, Director Office of Nuclear Reactor Regulation Ab)/(;'O (yV ij y '

U. S. NUCLEAR REGULATORY COMMISSION 9' L,k i b gg Washington, D. C. 20555 2 -

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Dear Mr. Denton:

u.5= %p h DOCKET NOS. 50-266 AND 50-301 k f TECHNICAL SPECIFICATION CHANGE REQUEST NO. 69 9 STEAM GENERATOR TUBE SLEEVING

• N POINT BEACH NUCLEAR PLANT UNITS 1 AND 2 In accordance with the provisions of Ib CFi Section 50.59, Wiscon-Sin Electric Power Company (Licensee) hereby requests amendments to Facility Liperating Licenses DPR-24 and DPR-27 for the Point Beach Nuclear Plant Units

. and 2 respectively. The purpose of these license amendments is to incor-porate certain changes into the Point Beach Nuclear Plant Technical Specifi-cation to permit repair of degraded or defective steam generator tubes by sleeving. Specifics of these Technical Specification changes and a discussion of the steam generator tube sleeving process are provided below and in the attachments.

A degraded tube is defined in the Technical Specifications as a tube that contains imperfections caused by degradation greater than 20% of the nominal wall thickness. Degradation which exceeds 50% of the nominal tube wall thickness is defined as a defect. The present Technical Speci-fications require that all tubes that leak or have degradation exceeding 40%

of the nominal tubewall thickness, which is defined as the plugging limit, shall be plugged prior to returning to power from the refueling or inservice inspection condition. A tube is plugged by placing a plugging device which may be secured by explosive, mechanical, or welding processes in both the hot leg and cold leg ends of the tube. Plugging removes a tube from service.

Methods have recently been developed to repair steam generator tubes by inserting sleeves inside the steam generator tubes. These sleeves bridge the degraded or defective portion of the original tube ana provide an effective means of repairing the tube rather than removing the tube from service. Sleeving techniques have been used in the repair of the San Onofre Unit 1 steam generators and at the R. E. Ginna plant. I During the fall 1981 Point Beach Nuclear Plant Unit 1 refueling outage, Licensee is planning to insert sleeves into several steam generator g dj 6

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J Mr. Harold R. Denton July 2, 1981 tubes as a demonstration of the sleeving process at Point Beach. To provide a thorough demonstration of the ability of the sleeving process to repair tubes and to affirm the integrity of the primary to secondary boundary, it is appro-priate to insert sleeves into ;everal defective tubes during this program.

Such a demonstration of the sleeving program can only be accomplished if the subject Technical Specification changes are granted.

The sleeves proposed for use in the Point Beach Nuclear Plant Unit 1 sleeving demonstration will be designed and analyzed to the latest edition of Section III of the ASME Boiler and Pressure Vessel Code as well as applicable Regulatory Guides. The associated materials and processes will also meet the requirements of the Code. Table 1 presents the specific requirements being addressed. The sleeves provided will span the degraded or defective area of the original tube from the tube end to above the steam generator tube-sheet beyond the degraded or defective area. The sleeve will also limit the leakage from the primary to secondary should the original tube be penetrated in the region spanned by the sleeve or contain a preexisting leaking defect.

The joints between the sleeve and the original tube at both the top and bottom of the sleeve will be formed by a brazing, mechanical, or combination process. The sleeve and joints to be used for the Point Beach Unit 1 demon-stration program will be of the same or similar design as the sleeves and joints that have been installed at Southern California Edison's San Onofre Nuclear Generating Station Unit 1. In a letter from Mr. D. M. Crutchfield of your Staff to Mr. R. Dietch of Southern California Edison dated June 8,1981, the NRC Staff reported on its ieview and approval of this sleeving process.

Confirmatory testing will be performed with the Point Beach size s'.eam generator tubing to demonstrate that data developed for San Onofre are applicable to the Point Beach steam generators. This will include leak rate testing and load carrying capability.

The sleeve and original tube will be inspectable using eddy current techniques. The corrosion resistance of the sleeve material, thermally treated Inconel 600, exceeds that of the original tube material. We antici-pate that during this demonstration twelve tubes will be sleeved. Approx-imately half of these tubes will contain degradation exceeding the Technical Specification plugging limit. All previous steam generator primary to secondary leakage rate monitoring commitments and permissible leakage allowance criteria, including those requirements from the November 30, 1979 Confirmatory Order for Point Beach Unit 1, as modified, would remain in effect.

Licensee has reviewed the requirements of 10 CFR Part 170 regarding the payment of fees for NRC license amendment reviews. We have determined that f( Point Beach Unit I this amendment request involves a, Class III fee in that a single safety is m is involved for which an NRC position has t'een previously established. S1 ,e a second essentfally identical unit is in-volved, a Class I fee is app,wable for the Point Beach Unit 2 license review.

Accordingly, we have enclosed .arewith a check in the amount of $4,400 for these amendment approval fees.

As required by the Cor .ission regulations, we have enclosed three signed originals and forty additional copies of this amendment request.

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Mr. Harold R. Denton July 2, 1981 Attached to each copy of the request are proposed Technical Spec fication page changes which reflect the change to the corrective action for tube degradation which exceeds the plugging limit as discussed in this letter. We request your approval of this amendment request so that a sleeving demonstra-tion program, including defective tubes, may be accomplished during the Point Beach Unit 1 fall refuelinn outage.

Very truly yot!rs, o

^s__

Sol Burstein Executive Vice President Enclosure (Check No. 625653)

Subscribed and sworn to before me This 2nd day of July,1581 WM$) ?PNw JL o -.w Notary Public State of Wisconsin MyCommissionExpiresp l )737, Copy to: NRC Resident Inspectcr Mr. C. F. Riederer - (PSCW)

Mr. Peter Anderson - (WED) l l

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ASME CODE AND REGULATORY REQUIREMENTS j

ITEM APPLICABLE CRITERIA REQUIREMENT

{ Sleeve Design Section III NB-3200,' Analysis Operating Condition Operating and Transient i Conditions i.

I Reg. Guide 1.83 S/G Tubing Inspectability Reg. Guide 1.121 Plugging Margin i

i Sleeve Material Section II Material Composition

! Section III NB-2000, Identification, Tests, and Examinations Code Case 1484-3 Mechanical Proporties i

Sleeve Joint 10CFR100 Plant Technical Specification i and License Requirements l

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