ML19320C805
| ML19320C805 | |
| Person / Time | |
|---|---|
| Site: | Beaver Valley |
| Issue date: | 06/17/1980 |
| From: | Woolever E DUQUESNE LIGHT CO. |
| To: | Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| References | |
| IEB-80-09, IEB-80-9, NUDOCS 8007180055 | |
| Download: ML19320C805 (2) | |
Text
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June 17, 1980 gen.P
!Jnited States Nuclear Regulatory Commission Region I 631 Park Avenue King of Prussia, Pennsylvania 19406 ATTENTION:
MR. BOYOE H. GRIER, DIRECTOR
SUBJECT:
Beaver Valley Power Station - Unit No. 2 Docket No. 50-412 IE Bulletin No. 80-09 Hydramotor Actuator Deficiencies Gentlemen:
We have reviewed I.E.
Sulletin No. 80-09 which was submitted with your letter dated April 17, 1980 which identified two problem areas pertaining to ITT General Controls (ITT-GC) Model AH-90 and NH-90 Series Hydramotor Actuators.
Actuators are selected using nomographs which are prepared by ITT-GC.
They have recently discovered that the friction forces and residual hydraulic forces were not accounted for when developing the selection nomographs. These forces could increase the actuator force up to 140 lbs. As a result, the actuators selected using these nomographs may be undersized.
The other problem identified by the I.E. Bulletin concerned the material used in the manufacture of about 368 springs. The material (5160 steel) has a lower design strength that the type 1060-1070 steel originally specified by ITT-GC. The springs made of this material, upon actuation of greater than three inch stroke, permanently set and the actuator force could be decreased by up to 160 lbs.
This results in improperly sized actuators which have insufficient spring tension to close the damper.
We have purchased our miscellaneous safety-related dampers from American Warming & Ventilating Company (2BV-185).
These dampers are furnished with ITT-GC series NH-90 hydramotor actuators. In addition, the inlet vane damper actuators for the safety-related centrifugal f ans from Buffalo Forge Company (2BV-162 ) and motor operated dampers provided on Ventilation Filter Assemblies from American Air Filter (2BV-157) are furnished with NH-90 series ITT-GC actuators.
To date, none of these actuators have been shipped.
8007180
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Mr. Boyce H. Grier, Director Page 2 Buffalo Forge Company, American Air Filter, and American Warming
& Ventilating Company are aware of these problems and are reevaluating their actuator selections. They will certify in writing that the actuator spring steel is Type 1060-1070 and that the springs will not permanently deform. Also, they will base their damper selection on revised nomographs which include the effects of friction forces and residual hydraulic forces.
DUQUESNE LIGHT COMPANY By E. Q. Woolever Vice President COPIES TO:
Dr. V. Stello (15)
Mr. W. G. Mcdonald (1)
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