ML20132D377
| ML20132D377 | |
| Person / Time | |
|---|---|
| Site: | Nine Mile Point  |
| Issue date: | 07/08/1985 |
| From: | Mangan C NIAGARA MOHAWK POWER CORP. |
| To: | Starostecki R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| References | |
| (55(E)-84-39), (NMP2L-0442), (NMP2L-442), NUDOCS 8507310357 | |
| Download: ML20132D377 (2) | |
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- gA N E T14e y NBAGARA MOMAWK POWER CORPORAT10N/300 ERIE BOULEVARD WEST. SYRACUSE. N.Y.13202/ TELEPHONE (315) 474-1511 July 8, 1985 (NMP2L 0442)
Mr. R. W. Starostecki, Director U.S. Nuclear Regulatory Commission Region I Division of Reactor Projects 631 Park Avenue King of Prussia, PA 19406 Re: Nine Mile Point - Unit 2 Docket No. 50-410
Dear Mr. Starostecki:
Enclosed is a revised final report, in accordance with 10CFR50.55(e), for the problem concerning an ITT Grinnell weld that was accepted on the basis of an incorrect radiograph.
This problem was reported via tel-con to P. Russ of your staff on September 13, 1984.
Interim reports were sent on October 15, 1984 and February 11, 1985.
Very truly yours, C.V.Mangan[
Vice President Nuclear Engineering and Licensing CVM/GG/cla (1101H) xc: Director of Inspection and Enforcement U.S. Nuclear Regulatory Commission Washington, DC 20555 R. A. Gramm, NRC Senior Resident Inspector Project File (2) 8507310357 850700 gg PDR ADOCK 05000410 S
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.A NIAGARA H0 HAWK POWER CORPORATION NINE MILE POINT - UNIT 2 DOCKET NO. 50-410 Final Report for a Problem Concerning Incorrect Radiograph (55(e)-84-39)
Description of the Problem During a review of ITT Grinnell wel d radiographs, it was observed that radiographs for welds CSH 25-7 ~WO15 and CSH 25-7 FW017 were identical.
Radiographic interpretation reports for both welds had been signed off as approved.
Apparently, one of the welds had not been radiographed.
The weld joi nt, not previously radiographed, has since been radiographed and found acceptable.
The subject weld is located in the high pressure core spray sy stem.
Evaluation of the duplication of radiographs detennined that, prior to January 3,
- 1984, 691 full-penetration circumferential fiel d wel ds were produced and radiographed.
These wel ds were depicted on 122 di fferent isometric drawings.
Welds radiographed after January 3,1984, were verified by Fiel d Quality Control to ensure that the correct weld was being radiographed.
Analysis of Safety Implications A sample of 60 welds from a lot size of 691 welds were selected at random, radiographed, and compared to the original s.
It was confirmed by re-radiograph that each weld had been radiographed, hence no duplication of radiographs existed for those welds.
The sample radiography did, however, identify that one weld had been misidentified.
As a result of the additional radiography, it can be determined statistically that there is a 98 percent confidence that 95 percent or more of the welds have been radiographed, and a 95 percent confidence that 94 percent or more of the welds were correctly identifled.
Because of the high confidence that o:ach weld has been radiographed, and that weld radiographs are properly identified, no further investigative action is required.
As originally stated in our previous report dated February 11, 1985, had these subject conditions remained uncorrected, it could not have adversely affected the safety of operations of the plant.
Corrective Action The misidentified weld will be re-radiographed in its entirety to properly identify the weld number.
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