ML19263B855
| ML19263B855 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 01/12/1979 |
| From: | TENNESSEE VALLEY AUTHORITY |
| To: | |
| Shared Package | |
| ML19263B852 | List: |
| References | |
| NUDOCS 7901240345 | |
| Download: ML19263B855 (1) | |
Text
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3 6-ENCLOSURE SEQUOYAH NUCLEAR PLANT UNITS 1 AND 2 INADEQUATE DESIGN Of liVAC PENETRATIONS NCR CEB 78-3 FIRST INTERIM REPORT Description of Deficiency During design review, it was discovered that the as-built configuration of the heating, ventilating, and air conditioning (llVAC) penetratiors was not accounted for in the containment design.
TVA supplied the contractor / designer, Chicago Bridge and Iron (CB&I), with inadequate load definition in the design specification.
TVA's design specification required CB&I to apply the total mass of the assembly at the end of the nozzle instead of at the center of gravity of the assembly. This causes overstresses in the containment shell in the area of the penetrations.
Safety Implications If this condition had gone uncorrected, the containment shell could have been overstressed in the area of the liVAC penetrations under load combinations involving a seismic event.
Thus, had this condition gone uncorrected, it could have adversely affected plant safety.
Corrective Action TVA has supplied CB&I with the proper loads and load applications to reanalyze the llVAC penetrations and will add supports as required to eliminate overstresses.
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