ML19260C863
| ML19260C863 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 01/30/1980 |
| From: | Mills L TENNESSEE VALLEY AUTHORITY |
| To: | |
| References | |
| NCR-20P, NUDOCS 8002060284 | |
| Download: ML19260C863 (2) | |
Text
s TENNESSEE VALLEY AUTHORITY CH ATTANOOGA. TENNESSEE 37401 400 Chestnut Street Tower II January 30, 1980 Mr. James. O'Reilly, Director Office of spection and Enforement U.S. Nuclea Regulatory Commission Region II - b ice 3100 101 Marietta 5 reet Atlanta, Georgi 30303
Dear Mr. O'Reilly:
SEQUOYAll NUCLEAR PLANT UNITS 1 AND 2 - RADIATION MONITORS SPURIOUS SICNALS - NCR 20P - FIRST INTERLM REPORT The subject deficiency was initially reported to NRC-0IE Inspector W. T. Cottle on January 4,1980, in accordance with 10 CFR 50.55(e).
Enclosed is our first interim report. We expect to provide additional information by March 5, 1980.
If you have any questions concerning this matter, please get in touch with D. L. Lambert at FTS 854-2581.
Very truly yours, TENNESSEE VALLEY AUTHORITY L. M. Mills, Manager Nuclear Regulation and Safety Enclosure Mr.VictorStallo,Jr., Director (Enclosure)!
cc:
Office of Inspection and Enforcement U.S. Nuclear Regulatory Commission Washington, DC 20555 1933 156 30/9 50M 2
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An Eaual Cooortunity Employer 8002060
ENCLOSURE SEQUOYAH NUCLEAR PLANT UNITS 1 AND 2 RADIATION MONITORS SPURIOUS SIGNALS NCR 20P 10 CFR 50.55(e)
FIRST INTERIM REPORT Description of Condition The readout instraments in the main control room for 12 radiation monitors were spiked upscale in unison for two hours on December 12, 1979, and for one hour on December 13, 1979.
The spikes generally peaked at one million counts per minute.
The 12 monitors identification numbers and their applications are listed below:
0-RE-90-132A Service Building Vent (Particulate)
U-R E-90-13 2 B*
Service Building Vent (Gaseous) 0-RE-90-101A Aux. Building Vent (Particulate) 1-RE-90-170 Boric Acid Evap. Condensers 1-R E-90-120*
Steam Generator Blowdown Liquid Mon.
1-RE-90-121*
Steam Generator Blowdown Liquid Mon.
0-RE-90-118
- Waste Gas Disposal System Gas Effluent bbn.
0-RE-90-123
' Component Cooling Water Heat Exchanger Liq. Mon.
1-RE-90-123 Component Cooling Water Heat Exchanger Liq. Mon.
2-RE-90-123 Component Cooling Water Heat Exchanger Liq. Mon.
1-RE-9 0-100B
- Shield Building Vent (Gaseous) 1-RE-90-104 Reactor Coolant Letdown Liquid Monitor
- Has radiological effluent e.ccitoring technical specification The upscale readings were determined to be caused by the operation of a heliarc welding machine in the Auxiliary Building, two floors below the elevation of the cable spreading room which is under the main control room. The monitor signal cables apparently picked up radio frequency interference produced by the welding machines.
The cables are run in cable trays.
Corrective Action TVA is evaluating the appropriate corrective action for this nonconformance and will provide additional information when a decision on the corrective action has been made.
1933 157