ML19309E086
| ML19309E086 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 04/11/1980 |
| From: | TENNESSEE VALLEY AUTHORITY |
| To: | |
| Shared Package | |
| ML19309E083 | List: |
| References | |
| NCR-CEB-80-12, NUDOCS 8004180367 | |
| Download: ML19309E086 (1) | |
Text
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O ENCLOSURE SEQUOYAll NUCLEAR PLANT UNIT 2 WALWORTll VALVE WEIGHT INCORRECT NCR CEB 80-12 10 CFR 50.55(e)
FINAL REPORT Description of Deficiency Incorrect motor operator weights were used in the piping load analysis for 3-inch piping in the Component Cooling Water System (CCS). These operators are manufactured by Limitorque and used on 3-inch globe valves manufactured by Walworth Company, Greensburg, Pennsylvania, and supplied by M.9'CO, Pittsburgh, Pennsylvania.
The three valves affected are two cantainment isolation valves and one flow control valve to the ccS pumps 2A and 2B suction header.
Two different weights are listed on the Walworth drawings for identical operators. One drawing indicates that the operator weighs 116 pounds while a weight for the valve operator has been determined to be 155 pounds.
The valve weight used in the piping load analysis incorporated an operator weight of 116 pounds.
Safety Implications Tkieloadsdeterminedinthepipingloadanalysesareusedinspecifying the piping supports.
The erroneous valve weight could, therefore, have resulted in installed supports which are inadequate to perform their required safety function. The 3-inch piping which penetrates containment could have failed, resulting in a violation of containment integrity.
The valve or pipe controlling water supply to the CCS pumps 2A and 2B could have failed causing loss of component cooling water supply to those pumps.
Corrective Action The piping load analyses were rerun using 195 pounds for the valve operator weight which is more conservative than the actual weight.
The resulting new loads were then applied to the support calculations.
As a result, the present support design was found to be inadequate.
The results of the correct valve data reanalyses will be placed on piping isometrics. The attachment to the pipe for one support (hanger number H10-1338) will require slight modification before fuel loadini-of unit 2.
No other support changes will be necessary.
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