ML19296D333
| ML19296D333 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 02/11/1980 |
| From: | TENNESSEE VALLEY AUTHORITY |
| To: | |
| Shared Package | |
| ML19296D332 | List: |
| References | |
| NCR-NEB-80-1, NUDOCS 8003030515 | |
| Download: ML19296D333 (1) | |
Text
CID ENCLOSURE SEQUOYAH NUCLEAR PLANT UNITS 1 AND 2 COPES-VULCAh VALVE WEIGHT INCORRECT NCR NEB 80-1 10 CFR 50.55(e)
FINAL REPORT Description of Deficiency Incorrect air-cperated block valve weights were used in the piping load analysis for the two-inch lines used to flush the UHI system check valves.
There are two block valves per plant unit, tag number 2-IA78RE, location numbers 9967 and 9985, located outside the containment. The valves are supplied by Westinghouse and are manufactured by Copes-Vulcan.
The,,
valve weight specified on the Copes-Vulcan drawing is nominally 240 pounds, whereas the actual weight has been determined to be approximately 405 pounds.
Safety Implications The loads determined in the piping system analyses are used in specifying tne piping supports.
The erroneous valve weight could therefore have resulted in installed supports which would be inadequate to perform their required safety functions. The two-inch piping, which connects directly into the Uh1 headers, could have failed, resulting in a lower UHI flow rate than that assumed in the plant safety analysis to mitigate a LOCA.
Corrective Action The piping system load analyses were rerun using the correct valve weight.
The resulting new loads were then applied in the support calculations, and the existing supports were found to be adequate to absorb the new loads.
The supports, one on either side of each valve, are of standard design, and had sufficient overdesign in these applications for the new loads.
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