ML20009D528
| ML20009D528 | |
| Person / Time | |
|---|---|
| Site: | University of Missouri-Columbia |
| Issue date: | 06/29/1981 |
| From: | Brugger R MISSOURI, UNIV. OF, ROLLA, MO |
| To: | Office of Nuclear Reactor Regulation |
| References | |
| 19339, NUDOCS 8107240146 | |
| Download: ML20009D528 (2) | |
Text
Research Reactor Facility UNIVERSITY OF MISSOURI g\\
Research Park l')
e Columbia, Missouri 65211
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' June 29, 1981 Telephone (314) 882-4211
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ed tP /g' Director of Licensing gh{D f.h,4 U. S. Nuclear Regulatory Commission
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Reference:
Docket 50-186 u,,, %
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s License R-103 g
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Subject:
Report as required by MURR Tech-3 nical Specification 6.1.h.2 Description On June 1,1981 while performing a routine semi-annual compliance check on the pool coolant flow instrument 921B, it was found the low flow scram set point was below the technical specification limit of 425 gpm. 0;.arating the reactor with the pool low flow scram set below 425 gpm is a deviation from MURR Technical Specification 3.3(a).
Analysis The reactor was in the shut down mode with all rods fully inserted.
To perform the compliance test, a pressure is externally connected to the transmitter to simulate flow conditions and to check the scram ret point. The instrument was found to be properly calibrated; however, the pool low flow 9218 scram tripped at 411 gpm which is below the Tec' nical Specification limit of 425 gpm.
The scram trip unit for pool flow 921B was replaced with a calibrated spare unit.
The new trip unit was, et and verified to be in compliance with Technical Specification 3.3(a).
The removed unit was bench tested for two weeks of continuous operation with no evidence of drift or instrument'anomalities.
The pool coolant flow scram 921 A and the differential pressure across reflector scrams were operable und within technical specification limits, either o have scrammed the reactor in a pool coolant low flow sit-uati c
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' June 29,1981 Page 2 Corrective Action The trip unit was replaced and the 921B compliance check performed.
Sincerel,
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J. C. McKibben Reactor Manager D
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Endorsement:
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-Reviewed and Approved
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(A Robert M. Bru ger Director JCMK:vs cc:
U._ S. Nuclear Regulatory Commission c/o Document Management Branch James Keppler, Director Regulatory Operations - Region'III
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Reactor Advisory Committee-Reactor Safety Committee j
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