ML20056D885

Application for Amends to Licenses NPF-37,NPF-66,NPF-72 & NPF-77,revising TS 3/4.4.5,Table 4.4-1 & Table 4.4-2,to Provide SG SRs for Sample Selection,Insp,Insp Frequency, Acceptance Criteria & Required Repts to NRC

ML20056D885
Person / Time
Site:	Byron, Braidwood
Issue date:	08/13/1993
From:	Bauer J COMMONWEALTH EDISON CO.
To:	Murley T NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM), Office of Nuclear Reactor Regulation
Shared Package
ML19310D609	List: ML20056D885 ML20056D889 ML20056D894 ML20056D895
References
NUDOCS 9308180215
Download: ML20056D885 (10)

Text

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/ E Commonwealth Edison .

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f- 1400 Opus PI c3 A, f - Downers Grove, Illinois 60515 ,

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• August 13,1993 1 E

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h . Dr. Thomas E. Murley, Director- }

Office of Nuclear Reactor Regulation  !

% . U.S. Nuclear Regulatory Commission 5 .. Washington, D.C.' 20555 1~

Attention: Document Control Desk p _

Subject:

Application for Amendment to Facility Operating Licenses: ,

iByron' Station Units 1 and 2  ;

(NPF-37/66 NRC Docket Nos. 50-454/455) ';

3

. Braidwood Station Units'1 and 2 I

(NPF-72/77; NRC Docket Nos. 50-456/457)

. i

" Steam Generator Tube Sleeving' Methodology" l

References:

1. ' WCAP-13698 Revision 1, "Lazer Welded Sleeves For 3/4 Inch q -Diameter Tube Feedring-Type And Westinghouse Preheater f' Steam Generators" s 2.1 Topical Report BAW-2045PA Revision 1, " Recirculating Steam Generators Kinetic Sleeve Qualification For 3/4 Inch Tubes" .;

4

Dear DE. Murley:

r a p Pursuant to 10 CFR 50.90, Commonwealth Edison Company (CECO) proposes to

' amend Appendix A, Technical Specifications of Facility Operating Licenses NPF-37,~NPF-66, NPF-72, and NPF-77. The proposed amendment request revises Technical Specification 3/4.4.5, " Steam Generators", and the associated bases to g' ' ' incorporate the sleeving of defective steam generator tubes as an alternative to tube plugging.

~ A detailed description ^of the proposed changes is presented in Attachment A. As f noted in this atte.chment, CECO is requesting that both the. Westinghouse laser

'. welded tube sleeve and the Babcock. and Wilcox (B&W) kinetic welded. tube sleeve .

be approved for use at Byron and Braidwood. The technical description of these -

processes are' described in WCAP-13698, Revision 1-and BAW-2045PA, Revision 1.

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Dr. T.E. Murley August 13,1993 i

The revis2d Technical Specification pages are contained in Attachinunt B.

The proposed changes have been reviewed and approved by the On site and Ofr-site Review Committees in accordance with CECO procedures. CECO has reviewed this proposed amendment in accordance with 10 CFR 50.92(c) and has determined that no significant hazards consideration exists as documented in Attachment C. An Environmental Assessment has also been completed and i is contained in Attachment D.

Attachment E contains the supporting Westinghouse documentation. Enclosed ,

please find one copy of WCAP-13698, Revision 1 (proprietary) and one copy of WCAP-13699, Revision 1 (non-proprietary). Also enclosed are a Westinghouse '

authorization letter, CAW-93-480, accompanying affidavit, Proprietary Information Notice and Copyright Notice.

As WCAP-13698 contains information proprietary to Westinghouse Electric Corporation, it is supported by an affHavit signed by Westinghouse, the owner of the information. The affidavit sets forth the basis on which the information may be withheld from public disclosure by the Com:nission and addresses with ,

specificity the considerations listed in paragraph (b)(4) of Section 2.790 of the Commission's regulations. Accordingly, it is respectfully requested that the information which is proprietary to Westinghouse be withheld from public disclosure in accordance with 10 CFR Section 2.790 of the Commission's regulations. i

' Correspondence with respect to the proprietary aspects of the items listed above or the supportmg Westinghouse Affidavit should reference CAW-93-480 and should be addressed to N. J. Liparulo, Manager of Nuclear Safety &  !

Regulatory Activities, Westinghouse Ylectric Corporation, P.O. Box 355, ,

Pittsburgh, Pennsylvania 15230-0355.

Attachment F contains the supporting Babcock and Wilcox (B&W) '

documentation. Please find enclosed one copy of BAW-2045PA, Revision 1 (pr>prietary). Included with this report is the NRC's acceptance letter of the

-. document and the associated Safety Evaluation Report. In a September 21, 1992 letter (JHT/92-205) from J.~ H. Taylor (B&W ) to the Document Control Desk, B&W requested that Topical Report BAW-2045PA, Revision 1 be treated as proprietary and withheld from public disclosure. Ar erding, it is respectfully requested that Topical Report BAW-2045PA, Revisie:.1, once again, be withheld from public disclosure in accordance with 10 CFR Section 2.790 of the '

Commission's regulations.

l l

Dr. T.E. Murley August 13,1993 l l

CECO is notifying the State ofIllinois of our application for these amendments by transmitting a copy of this letter and. the associated attachments to the designated State Official.

Braidwood Unit 1 is scheduled for a refueling outage beginning in late i February,1994. In order to be prepared for steam generator tube sleeving during this outage, CECO respectfully requests that the Staff review and approve this proposed amendment by February 1,1994.

• To the best of my knowledge and belief, the statements contained in this document are true and correct. In some respects these statements are not based on my personal knowledge, but on information furnished by other CECO employees, contractor employees, and/or consultants. Such information has ,

been reviewed in accordance with company practice, and I believe it to be reliable.  ;

Please address any comments or questions regarding this matter to this ofIice.  ;

Respectfully, 01f tY. wd Joseph A. Bauer l Nuclear Licensing Administrator i

JAB /gp state of- county of __ , , , , = _ _

Sianed befo e me on this - + '

OFFICl AL SEAL 0 #[1 19,blby.0 0 ,, / SANDbA C.LARA 4

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NOTARY f'Uin !C. STA1E OF ;LLIN0!$ '

otary Public . 1 # v: . ~ Mi COMVISS10N l XPiRES t/?b% :-

Attachments f 7FN - ~ ~ ~ "

cc: J. B. Hickman, Byron Project Manager - NRR R. R. Assa, Braidwood Project Manager - NRR H. Peterson, SRI - Byron (w/o Attachments E and F)

S. G. Dupont, SRI - Braidwood (w/o Attachments E and F)

B. Clayton, Branch Chief- Region III (w/o Attachments E and F)

Office of Nuclear Facility Safety - IDNS i

-t

t PROPOSED LICENSE AMENDMENT i

" Steam Generator Tube Sleeving Methodology" INDEX '

Attachment A Detailed Description of Proposed Change '

Attachtnent B Proposed Changes to Appendix A, Technical Specifications for Facility Operating Licenses NPF-37, NPF-66, NPF-72 and NPF-77 Attachment C 10CFR50.92 Significant Hazards Consideration  ;

Attachment D Environmental Assessment -

Attachment E Westinghouse Documentation Attachment F Babcock & Wilcox Topical Report BAW-2045PA, Revision 1 a

?

i ATTACIIMENT A i DETAILED DESCRIPTION OF PROPOSED CIIANGE Description of Current Requirements The existing Technical Specification 4.4.5, Table 4.4-1 and Table 4.4-2 provide the steam generatur (S/G) surveillance requirements for sample selection, inspection, inspection frequency, acceptance criteria, and required reports to the NRC.

Currently at Byron and Braidwood, if a steam generator (S/G) tube is found to be defective the only remedial action allowed by the Technical Specifications is to plug the tube. '

1 Bases for the Current requirements The surveillance requirements for inspection of the S/G tubes ensure that the  :

structural integrity of this portion of the RCS will be maintained. The program l' for inservice inspection of S/G t ibes is essential to maintain surveillance of the condition of the tubes and the e stent of any degradation. The primary to ,

secondary pressure boundary ir maintained by plugging all defective tubes.

Description of the Need for Amending the Technical Specifications At Byron and Braidwood, Unit 1 has four D-4 model S/Gs and Unit 2 has four D-5 model S/Gs. There are some noteworthy differences between D-4 and D-5 model S/Gs. The D-4's have .75" carbon steel tube support plates with drilled hole tube supports whereas the D-5's have 1.25" stainless steel support plates with Quatrefoil tube supports (see Drawing 1). All S/Gs have Inconel G00 tubes. The .,

D-4 S/G tubes were mill annealed and hard rolled into the tubesheet during initial  !

assembly. Subsequently, the D-4 tubes were shot peened in the tubesheet area and stress relieved in the U-bend area to relieve residual stresses. The D-5 tubes were heat treated and hydraulically expanded into the tubesheet during initial assembly. Over the past several refueling outages the number of S/G tubes plugged per outage has been increasil.g. At each site, Unit I has had more defective tubes than Unit 2 due primarily to the design differences between the D-4 and D-5 S/Gs mentioned above.

The number of S/G tubes requiring corrective action increased significantly at ,

Byron Unit I during the spring 1993 refueling outage. It is anticipated that Braidwood Unit I wiIl follow this trend in its spring 1994 refueling outage. In

_ )

order to minimize the number of plugged tubes, an alternate method of tube- '

repair is necessary to disposition defective S/G tubes. Consequently, two S/G

i Attachment A Page 2 j sleeving methodologies previously accepted by the NRC at other sites have been  !

chosen: 1) the laser welded sleeve developed by Westinghouse and; 2) the kinetic ,

welded sleeve developed by Babcock and Wilcox (B&W). l Description of the Proposed Amendment Specification 4.4.5.2. Steam Generator Tube Sample Selection and Inspection Most of the changes to the specification are contained in four inserts. The inserts reflect the option to repair tubes using sleeves and the resulting changes to the sample selection and inspection criteria. Also, the term " tubes" was expanded to

" tubes or sleeves" for clarification in the note on classifying inspections into categories C-1, C-2, and C-3.

Insert "A" adds a statement to clarify that after a sleeve is installed, it is considered part of the tube that it is repairing.

Insert "B" clarifies that once a defect has been repaired by a sleeve, the defect does not require reinspection per 4.4.5.2.a through c.

Insert "C" expands on the existing wording to include inspecting tubes with previously detected tube wall penetrations of greater than 20%, unless the tube has been plugged or sleeved. Also, it adds the inspection of sleeves with previously detected sleeve wall penetrations.

Insert "D" adds a requirement to inspect a sample of the previously installed sleeves and the remainder of the tube in which the sleeve was installed.

Specification 4.4.5.4. Acceptance Criterin This specification has several changes which reflect the option to repair S/G tubes using sleeves. The word " tube" is replaced by the phrase " tube or sleeve" acknowledging the primary to secondary pressure boundary inside a steam generator may now be a tube or a sleeve. The terms " repair" or "unrepaired" are being added to reflect the option to sleeve defects which require action by the acceptance criteria.

Insert "E" allows a defect greater than or equal to 40% of the tube wall thickness to be either plugged as before or now repaired using a sleeve.

Attachment A '

Page 3 Insert "F" ensures an inspection of a tube with a sleeve installed in the tube I will include the sleeve. ,

i Insert "G" defines the process of tube repair and identifies the processes to  ;

be used for repairing the tubes. The Westinghouse laser welded tube i sleeve, described in WCAP-13698 Rev.1, and the B&W kinetic welded tube l sleeve, described in Topical Report BAW-2045PA Rev.1, are the processes '

proposed to be used at Byron and Braidwood. '

Specification 4.4.5.5. Reports This specification is modified to include repaired tubes in the reporting j requirements previously required only for plugged tubes.  !

Table 4.4-2. Steam Generator Tube Inspection ,

This table is modified to include repair as an option at every reference to plugging -l of defective tubes.

Bases for 3/4.4.5. Steam Generators Sleeving is added as an option to plugging for defective S/G tubes. The -

Westinghouse WCAP 13698 Rev. I and the B&W Topical Report BAW-2045PA Rev. I are added as the technical bases for the sleeving of S/G tubes and j inspecting sleeves at Byron and Braidwood. Also, the pluggin'g limit for a i defective sleeve and the bases for this limit are added. Commonwealth Edison -

committed to validate the adequacy of any system that is used for periodic inservice inspection of the sleeves and as deemed appropriate, upgrade testing methods as better methods are developed and validated for commercial use. ,

f Bases for the Proposed Amendment  ;

This Technical Specification revision allows repair of defective S/G tubes with sleeves. Plugging will remain a parallel option in dispositioning defective S/G ,

, tubes. Also, when referring to a tube, the sleeve will be considered a part of the ,

tube for sample selection, inspection, inspection frequency, acceptance criteria, and required reports to the NRC.

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l Attachment A f Page 4 S/G tubes can be repaired by the installation of sleeves which span the area of l degradation and serve as a replacement primary to secondary pressure boundary  ;

for the degraded portion of the tube. This process returns the tube to compliance  ;

with the Technical Specification 4.4.5 acceptance criteria. The installation of Westinghouse laser welded tube sleeves is described in WCAP-13698 Rev.1, Laser  :

Welded Sleeves for 3/4 Diameter Tube Feedring-Type and Westinghouse Preheater ,

Steam Generators. The installation of B&W kinetic welded tube sleeves is described in Topical Report BAW-2045PA Rev.1, R.ecirculating Steam Generator Kinetic Sleeve Qualification for 3/4 Inch O.D. Tubes. These processes have been reviewed by Commonwealth Edison engineering and are endorsed as being  !

capable of sleeving degraded tube walls in the area of the tubesheet and the tube  !

support plates. These sleeving processes are qualified to repair degraded S/G tubes restoring the tube to function essentially as the original tube.  ;

i The laser welded sleeve described in WCAP-13698 Rev.1 is constructed of 1 thermally treated alloy 690 which is more resistant to corrosion than mill [

annealed alloy 600 used for construction of the S/G tubes. Two distinct types of  ;

sleeves are described; a tubesheet sleeve and a tube support sleeve. The ,

tubesheet sleeve is available in lengths from 27" to 36" and in two types; the full length tubesheet sleeve and the elevated tubesheet sleeve. The tube support ,

sleeve is 12" in length and can be installed in all tube support locations excludmg the top support plate. i The kinetic welded sleeve described in Topical Report BAW-2045PA Rev.1 is also  ;

constructed of thermally treated alloy 690 which, is more resistant to corrosion  ;

than mill annealed alloy 600 used for construction of the S/G tubes, as noted i above. Two distinct types of sleeves are described; a tubesheet sleeve and a tube support sleeve. The tubesheet sleeve is available in '11" and 17.5" lengths. The '

tube support sleeve is 11" in length and can be installed in all tube mpport locations excluding the top tube support plate. '

t The Westinghouse and B&W sleeves were qualified to meet the ASME Code, Regulatory Guides 1.121 and 1.83. The qualification ensures the sleeved tubes ,

will be acceptable under normal, transient, and accident conditions. Also,  :

inspection methods described in the WCAP and the B&W Topical Report ensure the Reactor Coolant System integrity.

Schedule Constraints q It is desired to have sleeving available for the upcoming refueling outage on Unit I at Braidwood beginning in late February 1994. In order to be prepared to i sleeve steam generator tubes during this refueling outage, Commonwealth Edison Company respectfully requests that this change be approved by February 1,1994.  ;

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ATTACIDENT B PROPOSED CHANGES TO APPENDIX A TECHNICAL SPECIFICATIONS FOR FACILITY OPERATING LICENSES NPF-37, NPF-66, NPF-72, and NPF-77 Revised Pages: 3/4 4-13 3/4 4-14 3/4 4-15*

3/4 4 3/4 4-17 3/4 4-18*-

3/4 4-19 B 3/4 4-3

.Pages marked with an asterisk (*) are not being revised and are only included for -

convenience.

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