ML20246P993

Monthly Operating Rept Summary for Mar 1998 for Univ of Missouri Research Reactor

ML20246P993
Person / Time
Site:	University of Missouri-Columbia
Issue date:	03/31/1998
From:	MISSOURI, UNIV. OF, COLUMBIA, MO
To:
References
NUDOCS 9805040358
Download: ML20246P993 (3)

Text

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UNIVERSITY OF MISSO'URI RESEARCH REACTOR OPERATIONS MONTHLY

SUMMARY

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1. / l MARCH 1998 AoW Prepared by:

Operations Staff i

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• IS APR

- . y March 1998 l- . The reactor operated continuously in March with the following exceptions

five shutdowns for scheduled maintenance and refueling; three unscheduled shutdowns.

L On March 20, a rod-not-in-contact-with-magnet rod run-in occurred when control blade 'A' disengaged from its magnet while an operator was performing a routine sample handling evolution.

The drive mechanism alignment was checked and the magnet and seating surface were cleaned. On

- Monday, March 23, the drive mechanism was removed to the electronics shop for its scheduled

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preventive maintenance procedure. No anomalies were discovered and its operation was tested satisfactorily. The cause of this and several previous unscheduled shutdowns of this type are specifically undetermined, but are thought to be related to the rigidity of the upper bridge area to  ;

which this drive mechanism is secured. Facilities Operations are designing a way to structurally stiffen this bridge area.

On March 23, a manual rod run in was initiated to investigate an unusual relay noise in control blade 'A' drive mechanism. The reactor was suberitical at the time during a normal startup.

Electronics technicians discovered part of the old blade full-in sensor under water, which they believe  ;

caused a ground loop that created the relay noise. Afl.er relocating and drying the blade full-in l a

wires, the problem has not recurred. j On March 27, a manual scram was initiated when the fire main pressure gauge iidicated a  !

less than acceptable pressure to maintain adequate emergency pool make-up water supply. A rupture in the fire main line occurred at a fire hydrant. The break was restored in approximately 45 j minutes.

Major maintenance items for the month included: dumping depleted pool deionization bed 'B' into drying barrels--loading new pool deionization bed 'L'; replacing the master board in the uninterruptible power supply (UPS) charging circuit; replacing diesel generator starting batteries; repairing the fire main loop UNSCHEDULED SHUTDOWNS Date No. Tvoe Cause 3/20/98 1079 Rod Run-In Blade 'A' disengaged from magnet 3/23/98 1080 Manual Rod Run-In Blade 'A' relay noise 3/27/98 1081 Manual Scram Fire main loop break

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1 OPERATIONS

SUMMARY

HOURS OPERATED THIS PERIOD 676-TOTAL HOURS OPERATED '210,666 HOURS AT FULL POWER THIS PERIOD 673 TOTAL HOURS AT FULL POWER 207,573

' INTEGRATED POWER THIS PERIOD 280 MWD TOTAL INTEGRATED POWER 80,640 MWD MAINTENANCE ACTIVITIES 03/02/98 Refueled - removed core 98-10, loaded core 98-11.

03/09/98 Refueled - removed core 98-11, loaded core 98-12.

'03/13/98 Dumped depleted pool DI bed 'B' into drying barrels--loaded new pool DI bed 'L',

03/16/98' Refueled . removed core 98-12, loaded core 98-13.

03/20/98 Refueled - removed core 9813, loaded core 9814.

03/23/98 Refueled removed core 98-14, loaded core 9815. Replaced master board in UPS charging circuit.

03/27/98- Refueled - removed core 98-15, loaded core 98-16. Repaired fire main loop break.

03/30/98 Refueled - removed core 9816, loaded core 98-17.

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