ML20058K689
| ML20058K689 | |
| Person / Time | |
|---|---|
| Site: | Monticello  |
| Issue date: | 03/08/1974 |
| From: | Mayer L NORTHERN STATES POWER CO. |
| To: | Oleary J US ATOMIC ENERGY COMMISSION (AEC) |
| References | |
| NUDOCS 9102130476 | |
| Download: ML20058K689 (1) | |
Text
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Mr. J F O'Ieary EDNN y,
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Dear Mr. O' leary:
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KIRTICELID NUCIIAR CENERATINC PIANT Docket No. 50-263 ticense Ib. DPR-22 Supplement No. I to Jannary 23, 1974 Report Entitled "Fermanent ?lant Changes to Acezarodate Equilibrium core Scram Rescrivity Characteristice" On January 23, 1974..ve submitted a report entitled " Permanent Plant than6es to Accomodate Equilibrium Core Scram Reactivity Characteristics."
In subsequeot discussions on the subject, you requested that we identify the measures taken to interface the Prompt Relief Trip System (FRT) without degrading aristing safety systems. n e PRT interfaces with the Reactor Protcetion System (RPs) and the Automatic Pressore Relief systes (APR).
. %e FRT does not degrade the capabi11ty of either of these systests.
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Ibe PRI receives isolated relay contact outputs from the RPS. The inputs to FRT channel A (divirf.on 1) are from RPS channels A (division IA) sud B (division IB). A single failure in PET channel A vill not disable both RPS channels A and B.
The relay contacts will prevent reflection into the remainder of cach RPS chsuncl.
The PRI has outpats 'to the relief valves through the APR system in several cases'. 1he PRT outputs are electrically par 811cled with the APR outputs. A short circuit of the PET output will open a relief valvc.
but vill not affect the APR. A hot short of the wxvna polarity on a FRT output will blow the fuses in the APR for one relief valve. The outputs
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from the PRT arv of the psme grade and configuration as the APR outputs.
Yours truly,
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L 0 Mayer, PE Director of Nucle.ar Support Services cc: J G Keppler G Chasw ff Einnesota Pollution control Agency iten. e i Prpins 1944 a
9102130476 740308 CF ADOCK 05000263 CF
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