ML20154M384

Monthly Operating Rept for Apr 1998 for Univ of Missouri Research Reactor

ML20154M384
Person / Time
Site:	University of Missouri-Columbia
Issue date:	04/30/1998
From:	MISSOURI, UNIV. OF, COLUMBIA, MO
To:
References
NUDOCS 9810200253
Download: ML20154M384 (3)

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1 UNIVERSITY OF MISSOURI RESEARCH REACTOR j OPERATIONS MONTHLY

SUMMARY

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APRIL 1998 k

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[- April 1998 p . The reactor operated continuously in April with the following exceptions: five shutdowns for scheduled maintenance and/or refueling; two unscheduled shutdowns.

. On April 1, a rod-not-in-contact-with-magnet rod run in occurred when control blade 'A' disengaged from its magnet during a routine blade shimming evolution. The offset rod drive

mechanism for control blade 'A' was thoroughly inspected and tested--including a pull test (Reactor

Test Procedure 21). The reactor was subsequently refueled and a normal startup was completed satisfactorily. On the subsequent scheduled maintenance day, the offset and drive mechanism were

' inspected again and electronics technicians thoroughly checked and tested the electronics. In an attempt to possibly isolate and identify a cause for this problem, electronics technicians switched i- - the power supplies for the control blade magnets. No further problems of this particular type have i since occurred.

On April 27, a wide range monitor (Channel #4) high power scram occurred during a normal i

L startup with the reactor at 10 kW. No actual high power condition was indicated or observed on any matrumentation. A thorough examination and testing of this nuclear instrument revealed no anomalies. The cause was believed to be spurious. A subsequent normal startup was completed -

t 1 satisfactorily.

5' Major maintenance items for the month included: removing redundant post indicating valve #3 j in the fire protection (wet) system; replacing the air regulator on the anti-siphon system; performing l the biennial change-out of control blade offset mechanism 'B'; installing the'new Gamma' Metrics .

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~ nuclear instrum'ent channel 5/6 power range recorder per modification package 9510.

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UNSCHEDULED SHUTDOWNS Date No. Tyne Cause 4/1/98 1082 Rod Rtin-In Control blade 'A' disengaged from magnet 4/27/98 1083 . Scram Spurious Channel #4 high power

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OPERATIONS

SUMMARY

HOURS OPERATED THIS PERIOD 642 .

TOTAL HOURS OPERATED 211,308 l HOURS AT FULL POWER THIS PERIOD . 640 I TOTAL HOURS AT FULL POWER 208,212 INTEGRATED POWER THIS PERIOD 267 MWD TOTAL INTEGRATED POWER 80,907 MWD  !

MAINTENANCE ACTIVITIES 04/01/98 Refueled - removed core 98-17, loaded core 98-18.

04/06/98 -Refueled removed core 98-18, loaded core 98-19.

04/13/98 Refueled - removed core 9819, loaded core 98-20. Removed post indicating valve #3 from the fire protection wet system. Replaced the air regulator to the anti-siphon system.

04/15/98 Refueled - removed core 98-20, loaded core 98-21.

04/20/98 _ Refueled - removed core 98-21, loaded core 98-22. Biennial change-out of offset mechanism 'B'. Installed new channel 5/6 Gamma-Metrics power range recorder per modification package 9510.

04/27/98 Refueled - removed core 98 22, loaded core 98 23.

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