ML20140F430

Forwards RAI Re Util 960412 Request for TS Amend to Approve Installation of Framatome Electrosleeves in Plant SGs

ML20140F430
Person / Time
Site:	Callaway
Issue date:	04/28/1997
From:	Thomas K NRC (Affiliation Not Assigned)
To:	Schnell D UNION ELECTRIC CO.
References
TAC-M95204, NUDOCS 9705020299
Download: ML20140F430 (4)

Text

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s April 28,1997 Mr. Donald Schnell Senior Vice President - Nuclear Union Electric Company Post Office Box 149 St. Louis, Missouri 63166

SUBJECT:

REQUEST FOR ADDITIONAL INFORMATION (RAI) REGARDING UNION ELECTRIC COMPANY'S APRIL' 12, 1996, REQUEST FOR TECHNICAL SPECIFICATION AMENDMENT TO APPROVE THE INSTALLATION OF FRAMATOME ELECTR0 SLEEVES IN THE CALLAWAY PLANT STEAM GENERATORS (TAC N0. M95204)

Dear Mr. Schnell:

The NRC staff has reviewed your April 12, 1996, request for amendment to the Callaway Plant technical specifications to approve the installation of Framatome Electrosleeves in the Callaway Plant steam generators. As a result of the review, the staff has determined that additional information is needed to complete the review. The information needed, which was discussed in a teleconference with your staff and Framatome on April 14, 1997, is detailed in the enclosure.

To assist the NRC staff in meeting its review schedule, we request that you respond to the RAI in writing within 30 days of receipt of this letter.

If you have any questions, please contact me at (301) 415-1362 Sincerely, Original Signed By Kristine M. Thomas, Project Manager Project Directorate IV-2 Division of Reactor Projects - III/IV Office of Nuclear Reactor Regulation Docket No. 50-483 DISTRIBUTION:

DocketJile? ACRS, TWFN

Enclosure:

Request for Additional PUBLIC PDIV-2 Reading Information JRoe OGC, 015B18 EAdensam WJohnson, RIV cc w/ encl: See next page WBateman AHowell, RIV KThomas EPeyton JStrosnider DOCUMENT NAME: CAL 95204.RAI n ()

0FC PDIV-2/LA PDIV-2/PM EMCB/IC h NAME KTbb:ye EMk JStrosniddr i DATE 4/0/97 4/FT/97 4/d/97 j l

OFFICIAL RECORD COPY g j / 1 020asa I NBC HLE CEAlifB COPY

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e Mr. D. F. Schnell April 28,1997 cc'w/ encl:

Professional Nuclear Mr. Otto L. Maynard Consulting, Inc. President and Chief Executive Officer 19041 Raines Drive Wolf Creek Nuclear Operating Corporation Derwood, Maryland 20855 P.O. Box 411 Burlington, Kansas 66839 Gerald Charnoff, Esq.

Thomas A. Baxter, Esq. Mr. Dan I. Bolef, President Shaw, Pittman, Potts & Trowbridge Kay Drey, Representative  ;

2300 N. Street, N.W. Board of Directors Coalition  :

Washington, D.C. 20037 for the Environment 6267 Delmar Boulevard  ;

Mr. H. D. Bono University City, Missouri 63130 Supervising Engineer, t Site Licensing -

Mr. Lee Fritz Union Electric Company Presiding Comissioner  :

Post Office Box 620 Callaway County Court House ,

Fulton, Missouri 65251 10 East Fifth Street '

Fulton, Missouri 65151 I U.S. Nuclear Regulatory Comission ]

Resident Inspector Office Mr. Alan C. Passwater, Manager '

8201 NRC Road Licensing and Fuels Steedman, Missouri 65077-1302 Union Electric Company Pcst Office Box 66149 Mr. G. L. Randolph, Vice President St. Louis, Missouri 63166-6149 Nuclear Operations Union Electric Company Mr. J. V. Laux, Manager P.O. Box 620 Quality Assurance Fulton, Missouri 65251 Union Electric Company Post Office Box 620 Manager - Electric Department Fulton, Missouri 65251 Missouri Public Service Comission 301 W. High Post Office Box 360 Jefferson City, Missouri 65102 Regional Administrator, Region IV U.S. Nuclear Regulatory Comission Harris Tower & Pavilion 611 Ryan Plaza Drive, Suite 400 Arlington, Texas 76011-8064 Mr. Ronald A. Kucera, Deputy Director Department of Natural Resources P.O. Box 176 Jefferson City, Missouri 65102

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& l Enclosure l

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CALLAWAY PLANT. UNIT 1 l

REQUEST FOR ADDITIONAL INFORMATION <

f FRAMATOME ELECT 0 SLEEVES i

!- 1. Past experience with the materials of construction of the reactor 4

coolant pressure boundary and in particular steam generator tubing has been that cracking has occurred in many of these materials even when not <

, predicted to occur or not predicted to occur as early as observed. An argument advanced by Framatome with regard to the electrosleeving l l application is that cracks in alloy 600 tubing will not propagate as  ;

! cracks into an electrosleeve. It appears from our review of the 1

electrosleeving 4cuments that NDE detection (and sizing) of postulated I a cracks in the sleeve is not addressed. This approach rests upon '

! metallurgical arguments about the expected performance of the new material. This approach departs from the the traditional approach of.  ;

providing inspection techniques capable of detecting (and sizing, as )

necessary depending upon the application) postulated cracks in repairs. i

! Provide a discussion of plans for addressing the staff's concern regarding your approach to NDE. In addition, provide a copy of the

references with key information on nanocrystalline material that are not i readily available to the NRC.

I 2. Provide the crack size (in percent through wall of combined layer of ,

1 parent tube and sleeve) that would be the limit for unacceptability at the Callaway Plant.

f 3. Provide the location of the defects (e.g., top of tubesheet, tube 2 support plate, etc.) for the defects discussed in Attachment 1 (Table 1) j of the September 24r 1996, supplemental information.

! 4. Provide a copy of the EDM calibration standard drawing.

5. Provide the results (or a reference to a submittal) from the )

l electrosleeve assembly leakage tests performed for 11/16 inch tubes.

6. Provide additional information pertaining to the number of EDM defects

used for UT qualification testing. Specifically, describe the makeup of the 77 and 99 EDM notches referenced on page 11-4 of the topical report (BAW-10219P, Rev. 1, March 1996). Correlate these EDM defect groups to j Attachment 2 (Table 2) of the September 24, 1996, supplemental information. In addition, revise the units from " percent throughwall" to " mils".

7. Provide the number of samples used to determine the thickness accuracy of +/- 2 mils.

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, 8. Page 11 of the February,1997, supplemental information stated that axial ID initiated cracks had to be 100 percent throughwall of the

parent tube to be detected by UT. Describe the sizes (length, depth) of

! these cracks.

i 9. Provide a list of references to foreign experience with electrosleeves,

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including Canadian experience.

10. Describe how the UT signal, generated from the parent tube flaw behind i the electrosleeve, will be dispositioned during the preservice

inspection and future inservice inspections. Explain the basis for this

, method of dispositioning. Explain how the UT analyst can determine whether the flaw resides in the parent tube or if it has propagated into the sleeve.

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