ML19321A788
| ML19321A788 | |
| Person / Time | |
|---|---|
| Site: | Rancho Seco |
| Issue date: | 03/06/1980 |
| From: | Mattimoe J SACRAMENTO MUNICIPAL UTILITY DISTRICT |
| To: | Engelken R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| References | |
| IEB-80-03, IEB-80-3, NUDOCS 8007240198 | |
| Download: ML19321A788 (2) | |
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4SMUD SACRAMENTO MUNICIPAL UTILITY DISTRICT O 6201 S Street, Box 15830, Sacramento, California 95813; (916) 452 3211 March 6,1980 U. S. Nuclear Regulatory Commission ATTN:
Mr. R. 11. Engelken, Director
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Region V Office of Inspection and Enforcement Ti 1990 North California Boulevard
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Walnut Creek Plaza, Suite 202 g;y Walnut Creek, CA 94596
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RE: Operating License DPR-54 b#
Docket No. 50-312 IE Bulletin 80-03 Loss of Charcoal From Type II, 2 Inch, Tray Adsorber Cells
Dear Mr. Engelken:
w In response to your letter of February 6,1980, which transmitted the subject IE Bulletin, the Sacramento Municipal Utility District is hereby submitting the requested information concerning its experience with Type II Adsorber Cells.
At Rancho Seco, the ventilation systems which make use of charco*al are fitted with Type II, 2 inch, tray adsorber cells provided by the Barnebey-Cheney Company, Model FC-1521. The construction of these trays does not utilize rivets for securing the perforated screen to the casing.
Rather, the screen is spot welded at an approximate interval of 1 inch. These trays are used in both nor-mal and ESF systems as follows:
126 Reactor Building Emergency Filter "A" 126 Reactor Building Emergency Filter "B" 126 Auxiliary and Spent Fuel Building Exhaust "A" 126 Auxiliary and Spent Fuel Building Exhaust "B" 192 Reactor Building Exhaust 6 Control Room Emergency Ventilation System Since initial installation, inspection and testing, and including the results of three refueling interval surveillances, a total of 2808 filter inspections have been accomplished. These were done on a total of approxi-mately 900 adsorber trays, including those which have been drawn from storage.
Of all these trays and numerous inspections, only one has been identified to have had an opening develop between the perforated screen and its casing. When the unit in which this tray was installed was tested, it barely passed the required leakage test and follow-up visual inspection identified a slight loss of charcoal.
Replacing the tray dramatically increased the leakage ef ficiency of the unit and subsequent inspections have continued to show no degradation. All testing and inspections have been performed in accordance with Section 5 of ANSI N510-1975.
8007240l31I CE
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U. 5. Nuclear ' Regulatory-Commission Page Two March 6, 1980 The most recent inspection and test was completed on all installed filters February 11, 1980 with all units and adsorber trays tested and inspected satisfactorily.
Respectfully submitted,
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lJ. J. Mattimoa Assistant, General Manager and Chief Engineer JJM:RJR:DDW:sc c: Director, Division of Fuel Facil3 :y and Materials Safety Inspection Office of Inspection and Enforcement U.S. Nuclear Regulatory Commission-Washington, D.C.-20555 t
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