ML19256G251
| ML19256G251 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 12/14/1979 |
| From: | TENNESSEE VALLEY AUTHORITY |
| To: | |
| Shared Package | |
| ML19256G247 | List: |
| References | |
| NCR-17P, NUDOCS 7912280552 | |
| Download: ML19256G251 (1) | |
Text
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ENCLOSURE SEQUOYAH NUCLEAR PLANT UNITS 1 AND 2 DEFECTIVE DESIGN OF CHARCOAL ADSORBER TRAYS NCR 17P 10 CFR 50.55(e)
FINAL REPORT Description of Condition The charcoal adsorber trays in the Control Building Emergency Air Cleanup System, the Auxiliary Eu11 ding Gas Treatment System, and the Containment Purge Air Cleanup System, were found to be defective. During testing of the filter systems the trays were found to leak charcoal between the perforated plate and the frame of the tray.
This leakage is the result of a poorly " pop-riveted" joint between the perforated plate and the fraee of the charcoal tray.
The charcoal adsorber trays were manufactured by Flanders Filters, Inc.
TVA purchased the trays from CTI haclear, the system supplier.
Safety Implications This condition decreases the efficiency of the filters and could provide a path for air to bypass the charcoal.
During LOCA conditions, this could have resulted in the release of excessive levels of radiation.
Corrective Actions The defective trays will be removed and sent back to CTI Nuclear to be repaired or replaced.
The filters at Sequoyah Nuclear Plant will be replaced by the filters from Watts Bar Nuclear Plant, which were manufactured by a different manufacturer.
Installation and testing of the new filters will be completed before initial criticality of unit 1.
The replacement filters will be tested to ensure they meet the requirements of ANSI 510.
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