ML20129H055
| ML20129H055 | |
| Person / Time | |
|---|---|
| Site: | Nine Mile Point  |
| Issue date: | 05/17/1985 |
| From: | Mangan C NIAGARA MOHAWK POWER CORP. |
| To: | Starostecki R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| References | |
| (55(E)-84-46), (NMP2L-0413), (NMP2L-413), NUDOCS 8506070456 | |
| Download: ML20129H055 (3) | |
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N3"M e NIAGARA MOHAWK POWER CORPORATION /300 ERIE BOULEVARD WEST. SYRACUSE, N Y.13202/ TELEPHONE (315) 474-1511 May 17, 1985 (NMP2L 0413)
Mr. R. W. Starostecki, Director U.S. Nuclear Regulatory Commiss fon 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 final report in accordance with 10CFR50.55(e) for the problem concerning tricentric valves supplied by Clow Corporation. This problem was reported via tel-con to W. Lazarus of your staff on October 17, 1984.
An interim report was submitted via our letter dated November 16, 1984.
4 Very truly yours, C. V. Mangan Vice President Nuclear Engineering & Licensing GG/cla i
xc: Director of Inspection and Enforcement U.S. Nuclear Regulatory Commission
' Washington, DC 20555 R. A. Gramm, NRC Senior Resident Inspector Project File (2)
(506070456850517 K 05000410 5
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f NIAGARA M0 HAWK POWER CORPORATION NINE MILE POINT - UNIT 2 DOCKET NO. 50-410 Final Report for a Problem Concerniag Tricentric Valves Supplied by Clow Corporation (55(e)-84-46)
. Description of the Problem It was observed that some of the subject valves had varying physical characteristics even though their specification requirements were the same.
As a result, the vendor was requested to inspect the valves and determine whether they would operate as required by the specifications.. Subsequent inspection and walkdown of all Category I and Category II valves identified the.following conditions.
.1.
. Valves are incorrectly wired.
- a'. Torque switches on actuators incorrectly wired..
- b. Position-seated wiring on valves which should be torque seated.
.2.
Check valves fail to close properly.
-3.
Valves.are installed' backwards.
- 4.
Valves have actuators installed in orientation other. than that shown on design drawing.
- Indicates an item identified in the interim report.
. Analysis of Safety Implications Incorrectly. wired valve operators could be inoperable and could prevent the valves from performing their safety function. Check valves which do not close properly could effect the safe operation of the system in which they are installed.- Valses installed backwards could fail to close and overstress the valve shaft preventing the valves frora performing their safety function..
Actuators installed in other than the seismically qualified orientation could affect the function and integrity of the safety-related valves.
If the conditions described above had gone uncorrected, they could have adversely affected the safety of operations of the plant. Other deficiencies identified in the interim report were analyzed and determined to have no safety implications.
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Corrective Action Item 1.
Engineering.and Design Coordination Report Nos. F20,531; F20,541; and Nonconformance and Disposition Report No. 11892 have been issued
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to correct torque switch and limit switch functions.
Drawing changes have been initiated. Completion of this work will be monitored through the work tracking system.
Item'2.- _During startup and testing, a problem has been identified with the
- 18-in. and 30-in. check valves which do not close with reverse
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. flow. The valves have been identified to Clow and are being evaluated for necessary rework. This effort will be completed'by July 1, 1985.
Item 3.
To verify that all valves are installed correctly, a complete field
-survey was conducted using' ultrasonic inspection to determine the as-installed valve orientation. The results of this survey were.
reviewed against drawing and system design requirements. All valves identified:as being installed backwards have been evaluated and either accepted as being adequate for the application or identified to be reversed by July-1, 1985.
. Item 4.-
To qualify all valves for any acceptable' orientation, a seismic analysis based on the worst-case orientation is being performed.
The purpose of this analysis is to qualify the Clow valves for all-as-installed orientations and to provide an envelope of Seismic Qualification for any future need to reorient a valve / actuator because of operating requirements. The worst-case seismic analysis will supersede the existing individual seismic reports. This effort will be completed by August 1, 1985.
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