ML20006E987

Application for Amends to Licenses NPF-9 & NPF-17,allowing Option of Using B&W Recirculating Steam Generator Kinetic Sleeve Qualification for 3/4-inch OD Tube Repair Process Described in Topical Rept BAW-2045(P)-A

ML20006E987
Person / Time
Site:	McGuire, Mcguire
Issue date:	02/15/1990
From:	Tucker H DUKE POWER CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML20006E988	List: ML20006E987 ML20006E992
References
NUDOCS 9002270044
Download: ML20006E987 (10)

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- Dukeibwer Cornpany Hu R hkn 4;$:

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fice President Charktte, NC 2hN2 - Nuclear Production

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February 15, 1990-

@ .U.S. Nuclear Regulatory Commission j ATTN: Document Control Desk-Washington,-D. C. =20355 Subjects' McGuire Nuclear Station, Units 1 and 2

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Docket Nos. 50-369 and 50-370 Proposed Technical Specification Amendment to Allow the-

'i Use of- the Babcock & Wilcox (B&W) Kinetic Sleeving Process for Steam Generator Tube Repair 1

,c Gentlemen: i This letter contains a proposed amendmant to the Technica'l Specifications N for;McGuire Nuclear Station (Facility Operating License Nos. NPF-9 and j

n NPF-17)?to' allow the option of.using the B&W Recirculating Steam Generator  ;

Kinetic Sleeve-Qualification for 3/4 Inch OD Tubes' repair process described '

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.in Topical Report BAW-2045(P)-A. This revision will provide McGuire with an  !

alternative other than plugging for handling defective steam generator

. tubes.

= Attachment N3.1 contains the justification / description / technical discussion. - no .signifit.r.nt hazards analysis, ' and environmental impact.

analysis. The proposed changes' to the Technical Spec)ficatilons in the form ofimarked pages are identified in Attachment No. 2.

1 McGuire-Unit 1 is.currentlycin a refueling outage. The results of steam 4 generator oddy current testing' indicate that'either tube plugging or tubo q sleeving will be required. In order to minimize the number of plugged-

. tubes, McGuire would-like to utilize the B&W sleeving process during this 1 outage.' Therefore, we request the staff review and approve this request *

' prior to April- 25, 1990. .This is the date we are currently scheduled to ;j onter Mode 4. If this approval date.cannot be met, please advise us as se~t. .i as such a> determination can be made.  !

6 Pursuant'to 10CFR50.91(b)(1), a copy of this amendment request has been j

provided to the appropriate North Carolina official. j Very truly yours, j q

W llal'B' Tucker

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Attachments  !

SF.L515 90022700441900215 %

PDR ADOCK 05000369 h 1

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U.S. . Nuclear Regulatory Commission A'ITN: Document Control Desk W February 15, 1990 Page 2 L xc: W/All Attachments Mr. S.D. Ebneter, Administrator U. S. Nuclear Regulatory Commission, Region 11 101 Marietta Street, NW, Suite 2900 Atlanta, Georgia 30323 i i

Mr. Dayne Brown, Chief E

Radiation Protection Branch, Division of Facility Services Department of Iluman Resources ,

701 Barbour Drive  !

,' Raleigh, N.C. 27603-2008 Mr. D.S.11ood, Project Manager Office of Nuclear Reactor Regulation, USNRC Washington, D.C. 20555 Mr. P.K. Van Doorn Senior Resident Inspector, USNRC McCuire Nuclear Station H&M Nuclear Consultants 1221 Avenue of the Americas New York, New York 10020 American Nuclear Insurers c/o Dottie Sherman, ANI Library 270 Farmington Avenue Farmington, CT 06032 INPO Records Center Suite 1500 1100 circle _75 Parkway Atlanta, Georgia 30339 Y

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• • U.S. Nuclear Regulatory Commission 4 ' ATTN ' Document Control Desk f February 15, 1990 Page 3 IIA 1. B. TUCKER,' being duly sworn, states that he is Vice~ President of Duke Power Company that he is aut.horized on the part of said Company to sign and

- f11e wit.h the U.S. Nuclear Regulatory Commission this revision t.o t.he McCuire Nucicar Station Technical Specifications,1.icense Nos. : NPF-9 and NPF-17 and, that all statements and matters set forth therein are true and '

correct to t.he best of his knowledge.

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nal B. Tucker. Vice President i

Subscribed and sworn to before me t.his day of .

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" U.S. Nuclear Regulatory Commission- 4 y -ATTN: Documen't Control Desk February 15, 1990 Attachment No. 1 i

Duke Power Company  ;

McGuire Nuc1 car Station Technical Discussion, No Significant Hazards Analysis, and Environmental Analysis t T

Justification / Description / Technical Discussion j Currently, the McGuire Technical Specification (TS) 4.4.5.4 states that a f steam generator tube.containing a defect is a defective tube. A defect is  !

defined as an imperfection of such severity that it exceeds the plugging '

limit. The plugging limit for McGuire is the imperfection depth at or '

beyond which the tube shall be removed from service and is equal to 40% of the nominal wall thickness. However, it should be noted that this definition does not apply to the area of the tube sheet region below the F*  ;

distance provided the tube is not degraded (e.g., no indications of cracking) within the F* distance.

During the current McGuire Unit 1 refueling outage, using a pancake type eddy current coil as compared to the bobbin-coil type eddy current coil, we have determined that approximately 400 steam generator tubes will require plugging. As an alternate to plugging we have determined that tube sleeving-is more desirable. The advantage of tube sleeving versus tube plugging is the tube will remain in service and the structural integrity of the tube is maintained with minimal reduction in flow and heat transfer _ capabilities.

The repaired tube f unctions in essentially-the same manner as the original tube. .Therefore, we request the NRC provide approval to allow McGuire the option of using the Babcock & Wilcox (B&W) Kinetic Sleeving Process for Steam Generator Tube Repair. This TS revision will provide McGuire with a desirable alternative for handling degraded steam generator tubes.

This' request requires referencing the B&W Topical Report BAW-2045(P)-A, '

" Recirculating Steam Generator Kinetic Sleeve Qualification For 3/4 Inch OD Tubes". This report was submitted to the NRC by .B&W letter dated June' 9,  !

1989 and' supplemented on December 12, 1989. This report received NRC approval by letter dated January 4, 1990 (James Richardson, NRC Director of .

Division of Engineering Technology to J.H. Taylor of B&W).

1 The following changes to the TSs are requested to support the use of the the-B&W tube sleeving process (see Attachment No. 2):

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+ Change TS 4.4.5.4.a.1 to include sleeve under Imperfection criteria;

+ Change TS 4.4.5.4.a.2 to include sleeve under Degradation criteria; l l

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? U.S. Nuclear Regulatory Commission ATTN: Document Control Desk 1 February 15, 1990 1

. Attachment No. 1 E :q

+- Change TS 4.4.5.4.a.3 to include sleeve under Degraded Tube criteria;

+ _ Change TS 4.4.5.4.a.4 to include sleeve under % degradation criteria;.

+ Change TS 4.4.5.4.a.5 to include sleeve under Defect criteria;

+ Change TS 4.4.5.4.a.5 from Plugging Limit to Repair Limit and add tube sleeving as an alternate to tube plugging, clarify F* tube requirements, and identify the B&W process to be used for tube sleeving.

• Change TS 4.4.5.4.b to allow sleeving as an alternate to plugging tubes that exceed the repair limit.

+ Change TS.4.4.5.5.b.3 to add a requirement to report repaired tubes as well as plugged tubes; and, 4 Change'the TS Bases 3/4.4.5, Steam Generators to add tube repair by

. sleeving and to' address F* tube requirements with respect to sleeving.

These changes incorporate tube sleeving into the existing surveillance-requirements specified in the TSs.

The purpose of the sleeving process is to repair a degraded steam generator tube in order to maintain the function and the integrity of the tube. The sleeve functions essentially in the same manner as~the original tube. B&W~

Topical Report BAW-2045(P)-A describes in detail the analytical methods used for design and qualification of the B&W' sleeve. The Topical also contains the results of the sleeve design verification which included analysis and confirmatory testing to demonstrate the acceptability of the. steam generator sleeving technique for defective tubes. The design and operating conditions specified for the sleeve bound the McGuire steam generator design conditions.

The sleeve design described in Topical Report BAW-2045(P)-A is qualified for two lengths, 11 inches and 17.5 inches. The lower end of each sleeve is located approximately 16 inches from the primary face of the tube sheet ~

(reference Figure 5.1.1 of the Topical Report). The shorter sleeve may.be utilized in all the steam generator tubes (including the peripheral tubes

- which typically do not allow the introduction of sleeves due to the close

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f proximity of the steam generator bowl in that area).- The longer sleeve extends further into the tube past the flow distribution baffle.

The sleeve material is thermally treated Alloy 690 Inconel with a specified wall thickness of 0.039 inches. The required minimum thickness is 0.027 inches based on primary side design pressure. This material has been l demonstrated to be much more resistant to corrosion phenomenon as detailed in Topical Report BAW-2045(P)-A.

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. U.S. Nuclear Regulatory Commission  :

A'ITN: Document Control Desk February 15, 1990 Attachment No. 1 The upper sleeve / tube joint is produced by a kinetic weld / expansion which is subsequently stress relieved. The lower joint is either a kinetic weld in the tube sheet or a mechanically scaled joint produced by rolling the sleeve '

in the tube sheet. Therefore, the structural integrity of the tube is-maintained by the sleeving process.

The adequacy of the sleeve to withstand cyclic loadings was demonstrated by B&W using fatigue testing. Fatigue testing' consisted of cyclic vibration, pressure, thermal, and axial loading. These tests were performed to demonstrate the structural adequacy of the installed sleeve. In all cases, the results of the tests indicated that the sleeve conformed to the design requirements of the steam generators. Table 4.2.2, " Steam Generator Design i Transients" of the Topical Report sammarizes the transients used to 'l establish sleeve loading, and the design and operating conditions listed in Table 4.2.1, " Design & Operating Conditions" bound those of McGuire.  !

i McGuire currently has a program for inservice inspection based on a modification of Regulatory Guide 1.83, Revision 1. If a defect mechanism i should ducelop in service, it will be detected during routinely scheduled inservice steam generator tube examinations.- Repair will be. required for all tubes or sleeves with imperfections exceeding the repair limit of 40% of the tube or sleeve nominal wall thickness per the TSs. ' Defective steam l

generator tubes can be repaired by the installation of sleeves which span the area of degradation, and serve as a replacement pressure _ boundary for the degraded portion of,the tube, allowing the tube to remain in service.

Steam generator tube inspections have demonstrated the capability'to-

-reliably detect wastage type degradation that has penetrated 20% of the original tube wall thickness. For tubes with degradation below the F*

distance, and not degraded within the F* distance, repair is not required.

If a tube is sleeved due to degradation in the F* distance, then any. defects in the tube below the sleeve will remain in service without repair.

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No Significant Hazards Analysis As required by 10 CFR 50.91, the following analysis is provided concerning-whether the proposed amendment request involves a significant hazards

' consideration as defined in 10 CFR 50.92. Standards for determination that an amendment request does not involve a significant hazards consideration are if the operation of the facility in accordance with the proposed amendment would not:

1) Involve a significant increase in the probability or consequences of an accident previously evaluated; or,

2) Create the possibility of a new or different kind of accident from any previously evaluated; or, i l

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V.S. Nuclear. Regulatory Commission ATTNs Document Control Desk February 15, 1990 Attachment No. 1. i

3) Involve a significant reduction in a margin of safety.

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Operation of McGuire in accordance with the proposed amendment would not I involve a significant increase in the probability or consequences of an accident previously evaluated. Considering the function of the sleeve, the principal accident associated with this amendment is the steam generator tube rupture accident. The steam generator sleeve has_been analyzed and tested to the operating and design conditions of the original tube as documented in Topical Report BAW-2045(P)-A. The Topical Report contains the.

design verification results from the analysis and confirmatory testing performed'on the sleeve. The probability or consequences of this previously ,

evaluated accident does not involve a significant increase since the sleeve  !

meets the' original tube design conditions and the structural integrity of the tube is maintained by the sleoving process, and. surveillance requirements. The sleeve is less susceptible to the identified stress _

corrosion failure mechanisms of the original tube because of the B&W i specified installation process and the use of improved material (Alloy  !

Inconal 690); therefore, the potential for primary to secondary leakage is j also reduced by the addition of a steam generator _ tube sleeve. The 1-continued integrity of the sleeve will be verified by TS inspection requirements and the' sleeve will be plugged in accordance with TSs If a necessary. The use of sleeving is bounded by our existing LOCA analyses. 1 For the purpose of this analyses, 20 sleeves have the same effect as plugging one tube. This number is taken from the B&W Topical Report. Our  !

current tube plugging limit is-6%.

Operation of McGuire in accordance with the proposed amendment would not

. create the possibility of a new or different' kind of accident from any accident previously evaluated. The purpose of the sleeve is to repair a _

defective steam generator tube to maintain the function and integrity of the {

tube as opposed to plugging and removing the tube from service. The sleeve functions in essentially the same manner as the original tube and has been analyzed and tested for steam generator design conditions. The sleeve is less susceptible to the identified stress corrosion failure mechanisms of ,

the' original tube because of the B&W specified installation process and the use of improved material (Alloy Inconel 690); therefore, the potential for 1 primary to secondary leakage is also reduced by the addition of a steam generator tube sleeve. The continued integrity of the sleeve will be verified by TS inspection requirements and the sleeve will be plugged in accordance with TSs, if necessary. Repairing a steam generator tube to a serviceable condition utilizing the proposed sleeve process does not create  :

the possibility of a new or different type of accident since the sleeve'is a i passive component with failure mechanisms that are similar to the original tube.

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-U.S. Nuclear Regulatory Commission.

ATTN: Document Control Desk

' February 15, 1990-Attachment No. 1 Operation of McGuire in accordance with the proposed amendment would not I involve a significant reduction in a margin of safety. The structural r integrity of the tube is maintained by the installation of the sleeve and the sleeve / tube weld. The potential for primary to secondary leakage is "

reduced by the addition of the steam generator tube sleeve.- The sleeve is made of Alloy 690 and is not. subject to the same failure mechanisms of the original tube. The effects of sleeve installation (versus tube plugging) on  ;

steam generator performance, heat transfer, flow restriction, and steam generation capacity were analyzed and described in the Topical Report. The results show that plugging one tube is equivalent to the heat transfer reduction of sleeving 48 tubes, the primary flow reduction of sleeving 20 ~i tubes, and the loss of steam generation capacity of sleeving 40 tubes. This ,

means sleeving is preferable to plugging when considering core margins for most safety analysis. Furthermore, the use of sleeving is bounded by our existing LOCA analyses. For the purpose of this analyses, 20 sleeves has the same effect as plugging one tube.

Environmental Inspact Analynis One advantage to using the B&W steam generator tebe siceving process is that  ;

one of the major. design objectives during the development of the process- .

was to minimize personnel exposure. The results of a personnel exposure- i study-are presented in Section 7.2 of the Topical Report. The conclusion is that tuba sleeving provides a radiological economic alternative to plugging.

and removing tubes from service.

Tho' sleeving process does result in radioactive waste which is considerad disposable and cannot be reused. The solid volume produced during the i installation of 50 sleeves is approximately 0.75 cubic feet. This waste consists of nylon tubing, stress relief heaters, roll. expanders, cleaning hones, and water. The c1 caning hones (less than one percent of the waste) ,

are the only components that will come in contact with the primary system. .'

This contact will result in an expected hone radiation reading of- t approximately 1-2 R/hr after the usable life of the hone. The remainder of '

the waste is considered to be extremely low level waste. The cleaning water will be retrieved ~and piped to the station radioactive waste water treatment system.. Approximately one gallon per each tube will be required.

Additional wastes will be produced consisting of protective clothing, tape, ,

plastic bags, and other materials normally used in a radioactive environment. This waste is also' considered extremely low level waste and

.will be processed and disposed of in a low level waste burial facility. The amount of waste created using the sleeving process is comparable to that created by tube plugging.

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U.S.. Nuclear Regulatory Commission ATTN Document Control' Desk' ,

February 15, 1990~ ,

. Attachment No. I l The proposed. amendment does not involve a significant hazards consideration, nor increase the types and amounts of effluents or waste that may be released offsite, nor increase individual or cumulative occupational radiation exposures. Therefore, the proposed TS amendment meets the criteria given in 10 CFR 51.22(c)(9) for a categorical nxclusion from the requirement for an Environmental Impact Statement.

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l1 U.S. Nuclear Regulatory Conunission "l - ATTN: Document Control Desk February 15, 1990 i

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Attactuaont No. 2-Duke Power Company Proposed Changes to McGuire Technical Specifications

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