ML19345G169
| ML19345G169 | |
| Person / Time | |
|---|---|
| Site: | Haddam Neck File:Connecticut Yankee Atomic Power Co icon.png |
| Issue date: | 03/12/1974 |
| From: | Hartley F CONNECTICUT YANKEE ATOMIC POWER CO. |
| To: | Anthony Giambusso US ATOMIC ENERGY COMMISSION (AEC) |
| References | |
| AO-74-04, AO-74-4, CYH-2611, NUDOCS 8103090817 | |
| Download: ML19345G169 (2) | |
Text
"
8 CONNECTICUT YANKEE ATOMIC POWER COMPANY Cw/
HADDAM NECK PLANT
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V,x-Mr. A. Giambusso j
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Deputy Director for Reactor Projects
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MAR 151974 -
1 Directorate of Licensing
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[I Office of Regulation
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[y United States Atomic Energy Commission
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-.m Washington, D. C. 20545 M/
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Dear Mr. Giambusso,
As defined by Technical Specifications for Connecticut Yankee Atomic Power Station Section 5.3, the following infomation involving possible degradation of one of four containment air charcoal filters is reported as Abnormal Occurrence 74-4.
The Connecticut Yankee Reactor Containment Atmospheric Control System includes a filtration system for removing radioactive fission products from the containment atmosphere following an incident which releases radioactive fission products from the core. The filtration system utilizes the air recirculation fans as a driving force. The filters are located in fear separate banks connected to the inlet plenums of the four air recirc-The filter banks consist of moisture separators, absolute ulation fans.
type filters and activated charcoal filters.
dackup protection against overheating of the charcoal is provided in the form of a charcoal spray This system is included in each charcoal filter bank and supplies system.
borated water from the Residual Heat Removal Systen to the face of the filters through nozzles.
During the routine weekly reactor containment inspection conducted on March 1,1974, dry boric acid was observed on.the floor adjacent to the Further inspection within the filtration
- 4 air recirculation fan unit.
unit revealed boric acid deposits at the outlet or downstream side of at least twenty nine of eighty charcoal filter units. A detailed inspection of the charcoal filters from the inlet or upstream side revealed boric acid deposits of varying amounts on at least fifty five of the eighty filters in the #4 containment air recirculation fan unit. Leabge past the charcoal filter spray isolation valves provided the borated water path from the residual heat removal system to the filters in the #4 air recirculation unit.
Replacement charcoal filters have been ordered and are expected to be Representative charcoal filters will available within two to three weeks.
be removed from the #4 air recirculation unit and will be tested for iodine rO e.>.L t = 5 7/63o M t?
Mr. A. Giambusso fiarch 12, 1974 removal efficiency. Those filters selected for efficiency testing will represent the range from non-contaminated filters to filters having consid-erable boric acid position. The charcoal filter spray header isolation valve was disassembled and a mechanical obstruction in the gate valve groove was removed by filing.
The Containment Air Recirculation / Filtration System is designed to perform its function with only three of the four operable. The other three units were inspected and only one of two hundred forty charcoal units was observed to have slight boric acid contamination at the outlet.
Further inspect!cns from the inlet side of the other three units are planned.
Very truly yours, f
.s/
sk
't. W.
rtley Plant Superintendent RHG/bn cc: James P. O'Reilly, Director Region 1 Directorate of Regulatory Operations U. S. Atomic Energy Commission King of Prussia, Pennsylvania 19406 1
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