ML20237B546

Forwards Proprietary & Nonproprietary Safety Evaluation (SE) Accepting Util 870915 & 0925 Ltrs Re Steam Generator Tube Rupture on 870715.Findings Stated in Confirmatory Action Ltr .Proprietary SE Withheld (Ref 10CFR2.790)

ML20237B546
Person / Time
Site:	North Anna
Issue date:	12/11/1987
From:	Engle L Office of Nuclear Reactor Regulation
To:	Stewart W VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
Shared Package
ML20237B548	List: ML20237B546 ML20237B598
References
CAL, NUDOCS 8712160339
Download: ML20237B546 (2)

Text

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. . .. g December 11, 1987 Docket No. 50-338 ENCLOSURE 1 CONTAINS PROPRIETARY INFORMATION TO BE WITHHELD FROM Mr. W. L. Stewart PUBLIC DISCLOSURE PURSUANT TO

) Vice President - Nuclear Operations 10 CFR 2.790 Virginia Electric and Power Company Post Office Box 26666 Richmond, Virginia 23261

SUBJECT:

PROPRIETARY SAFETY EVALUATION (SE) FOR OPERATION AT 100% POWER FOR NORTH ANNA POWER STATION, UNIT NO. 1 (NA-1)

REGARDING STEAM GENERATOR TUBE RUPTURE (SGTR) ON JULY 15, 1987 We have completed our review of your letters dated September 15 and September 25, 1987 regarding the NA-1 SGTR (July 15, 1987). Included in our review was the Westinghouse Electric Corporation Report, " North Anna Unit 1 Steam Generator Tube Rupture and Remedial Actions Technical Evaluation," dated i l September 1987.

l As stated in the enclosed proprietary SE, we find that you have (1) adequately

_ demonstrated the primary failure mechanism leading to the July 15, 1987 SGTR event was fatigue caused by flow-induced vibration, (2) adequately identified the major causal factors leading to this event, and (3) implemented acceptable l diagnostic and corrective measures to prevent a similar fatigue failure in i the future. In addition, we have reviewed the results of operation at 50%

power with respect to SG integrity and find it to be acceptable.

i Our findings, as stated above, were stated in our November 5, 1987 Confirmatory Action Letter allowing NA-1 to operate at 100% percent of licensed power.

A non proprietary version of the SE is being provided to the service list and the Public Document Rooms.

Sincerely, ,

I 8712160339 871211 Original signed by {

PDR ADOCK 05000338  !

S PDR '

Leon B. Engle, Project Manager Project Directorate 11-2 Division of Reactor Projects-I/II Office of Nuclear Reactor Regulation

Enclosures:

1. Proprietary Safety Evaluation ENCLOSURE 1 CONTAINS PROPRIETARY 3

2. Non-Proprietary Safety Evaluation INFORMATION TO BE WITHHELD FROM  !

PUBLIC DISCLOSURE PURSUANT T0 cc w/Non-Proprietary Safety Evaluation: 10 CFR 2.790 See next page L L P D.P l 0 r LEngle B Gta as 12/l0/87 12/m /87 12 /0/87 12/ 9/87 1

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1 DISTRIBlJTION I

w/ Proprietary SE w/Non-Proprietary SE Docket File

• Docket, File.

PD22 Reading NRC & Local PDRs L. Engle < r r - F'ha"7.

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E. Murphy H. Berkow i T. Murley D. Miller  !

R. Starostecki OGC-Bethesda l L. Shao J. Partlow j A. Thadani E. Jordan j F. Miraglia ACRS (10) '

S. Varga G. Lainas {

N. Grace, R-II L. Reyes, R-II F. Cantrell, R-II J. Caldwell, Resident Inspector i

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