ML20084V202

Forwards Braidwood Unit 1 1995 Interim Plugging Criteria 90 Day Rept, Per Draft GL, Voltage-Based Repair Criteria for Repair of Westinghouse Tubes Affected by Outside Diameter Stress Corrosion Cracking

ML20084V202
Person / Time
Site:	Braidwood
Issue date:	06/07/1995
From:	Tulon T COMMONWEALTH EDISON CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML20084V204	List: ML20084V202 ML20084V210
References
BW-95-0064, BW-95-64, NUDOCS 9506130448
Download: ML20084V202 (3)

Text

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? X,,,- 4 Commonwerith lilium Company Braitlwood Generating Str%n

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fj7 Route el, Ilox 8 6 liraceville, IL M 607 9619 TelHi%I W 2801 s'

June 7,1995 BW/954064 Document Control Desk ,

[ U.S. Nuclear Regulatory Commission  ;

Washmgton, D.C. 20555

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Subject:

Braidwood Station Unit 1 l Steam Generator Interim Plugging Criteria 90 Day Report

[. NPF-72; NRC Docket No. 50-456

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References:

1. November 23,1994, Letter from Denise M. Saccomando to Office of Nuclear Reactor Regulations, Braidwood Unit 1 Mid-Cycle Inspection Plans.

2. February 27,1995, Letter from Denise M. Saccomando to U.S. l l Nuclear Regulatory Commission, Additional Information Regarding

! Braidwood Unit i Mid-Cycle Outage Plan.

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3. March 1,1995, Letter from Denise M. Saccomando to U.S. Nuclear j

( Regulatory Commission, Braidwood Station Unit 1 Mid-Cycle Inspection.

4. March 8,1995, letter from Denise M. Saccomando to U.S. Nuclear Regulatory Commission, Safety Assessment for Braidwood Unit 1 Mid-Cycle Outage AIM 05.

5. Draft Generic letter, " Voltage-Based Repair Criteria for the Repair of Westinghouse Steam Generstor Tubes Affected by Outside Diameter J Stress Corrosica Cracking," issued for public comment on August 12, 1994.

! In Reference 1, Braidwood Station committed to follow the requirements of Reference 5 with exceptions as noted in references I through 3. One of the requirements of the Draft Generic letter is to issue the final results of the inspection and tube integrity evaluation to the staff within 90 days following restart.

l l Pursuant to this requirement, Comed is submitting the enclosed report of results from the

! Braidwood Unit 1 End-of-Mid-Cycle 5 (AIMOS) steam generator inspection. Startup (Mode 2) from AIMOS was conducted on March 13,1995.

Attachment A to this letter contains the 90 day report for Braidwood Unit 1. The following

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, l. A detailed summary of the AIM 05 inspection results is provided in tabular and graplucal fonn through each of the following-

a. The results of the tube integrity evaluation, including the conditional burst probability and main steam line break leak rate (prelinunuy results were provided in Reference 4 prior to resumption of power operation from '

A1M05).

b. An updated evaluation of the voltage growth rates.

2. The mima *~I leakage based on actual measured EOMC vokage distribution '

did not exceed the leak limit, y

3. No circumferential crack-like indications were hai at the tube support plate intersections; although, circumferential crack-like indications were detected in the tube roll transition region at the top of the tubesheet

4. No indications were identified to extend beyond the -E- of the tube support plate.

5. The calculated ~=ii+6' burst probability did not exceed I x 10'*.

No tubes were removed from the Steam Generators; therefore, no metallurgical results of pulled tubes are anilable.

A**-I-* B contains a review of the programs which were implemented to mitigate SG tube degradation. This review was performed to assess the effectiveness of each program on the increase in voltage growth rates.

Please direct any questions regarding this sub'mittal to Doug Huston, Braidwood Licensing" Supervisor, (815) 458-2801, extension 2511.

Yours truly, A

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/ tation Manager Braidwood Nuclear Station TJT/DH/dla Attachments cc: S. G. DuPont, Sr. Resident inspector, Braidwood R. R. Assa, Braidwood Project Manager, NRR J. B. Martm, Regional Administrator, Rill J

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Attachment A Braidwood Unit 1 1995 Interim Plugging Criteria 90 Day Report L

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