ML20084J262
| ML20084J262 | |
| Person / Time | |
|---|---|
| Site: | Quad Cities  |
| Issue date: | 02/26/1973 |
| From: | Stephenson B COMMONWEALTH EDISON CO. |
| To: | Anthony Giambusso US ATOMIC ENERGY COMMISSION (AEC) |
| Shared Package | |
| ML20084J247 | List: |
| References | |
| BBS-73-32, NUDOCS 8305120286 | |
| Download: ML20084J262 (1) | |
Text
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Com e:lth Edison
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Quad-Cn.cs Nucint Pow:r St tion Post Office Box 216 Cordova, Illinois 61242 Telephone 309/654-2241
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i February 26, 1973 N
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Y o>il tcos Mr. Angelo Giambusso Deputy Director of Reactor Projects Directorate of Licensing U. S. Atomic Energy Commission Washington, D. C.
20545
Reference:
Quad-Cities Nuclear Power Station, Unit 1 Docket No. 50-254, License DPR-29, Appendix A Section 1.0. A.2 and 3 2. A.
Dear Mr. Giambusso:
The purpose of this letter is to inform you of the details concerning the setpoint drift of dPIS-1-2353 The setpoint was found to be at 151 inches of water increasing during a routine calibration on February 15 1973 This is contrary to Section 3 2. A. of the Technical Specifications which requires the switch to trip at 5300% (150 inches of water).
The switch is a Barton Model 280.
This switch is used to measure a dP across an elbow tap in the steam line of the HPCI system and will isolate the system on a high flow.
The one inch drift of the switch is considered insignificant with respect to the isolation function.
Drift problems have been encountered previously with this instrument and a setpoint change from 150 inches to 147 Jg inches of water was made in January.
Apparently this is NWA still an inadequate margin to prevent drif t beyond the LCO
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during the interval between calibrations.
A further decrease in setpoint is being reviewed to increase this margin.
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$g Very truly yours, Nu
$8 COMMONWEALTH EDISON COMPANY QUAD-CITIES NUCLEAR POWER STATION c( '
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- /7. - B. B. Stephenson r M' y 1403 Superinte; ~ int BES/zm
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