ML20141H642

Monthly Operating Rept for Jan 1997 for Univ of Mo Research Reactor

ML20141H642
Person / Time
Site:	University of Missouri-Columbia
Issue date:	01/31/1997
From:	MISSOURI, UNIV. OF, COLUMBIA, MO
To:
References
NUDOCS 9708010053
Download: ML20141H642 (3)

Text

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OPERATIONS MONTHLY

SUMMARY

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January 1997 Prepared by: )

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9 9 January 1997 The reactor operated continuously in January with the following exceptions: seven shutdowns to perform scheduled maintenance and/or flux trap changes and refueling; seven unscheduled shutdowns.

On January 5, a reactor scram occurred due to the loss of facility electrical power when a remote switching station--external to the reactor facility--experienced a failure which caused the loss of one phase of the 480 VAC incoming line to the facility. Repairs were completed and facility electrical power was restored in approximately six hours. The facility emergency generator supplied power to essential instruments and lighting during the outage.

On January 7, while the reactor was suberitical during a normal reactor startup, a manual reactor scram was initiated when the reactor operator noted abnormalindications on nuclear instrument channel #2 (intermediate range monitor). The channel #2 detector was determined to be faulty and was replaced and tested satisfactorily. During the subsequent startup, with the reactor at approximately 37 kW, a spurious nuclear instrument channel #4 (wide range monitor) high power scram occurred. No actual high power was indicated on any other instrumentation. Electronics technicians replaced the channel #4 drawer picoammeter and the instrument tested satisfactorily, i On the succeeding startup, with the reactor suberitical, another spurious channel #4 high power scram occurred. Again, no actual high power was indicated on any other reactor instrumentation.

Electronics technicians investigated the channel #4 range switch -which was being switched between ranges at the time of the scram. The range switch was removed and thoroughly cleaned and tested and subsequently reinstalled and tested satisfactorily. The reactor was then returned to normal operation.

On January 26, a manual rod run-in was initiated when the reactor operator noted the apparent failure of the pool outlet temperature (pool Tu RTD 901C) indication. While not part of the reactor safety system, this temperature indication supplies one of the input variables to the primary power calculator, which supplies a digital indication of reactor thermal power output.

Electronics technicians replaced the (MV/I) millivolt transmitter for pool Tn RTD 901C and a satisfactory compliance check was performed. The reactor was then refueled and returned to normal operation.

On January 29, a reactor loop low flow scram occurred when the breaker for primary pump 501B motor tripped. The motor was subsequently discovered to be shorted out and was replaced with a spare. During the subsequent startup, with the reactor at approximately 15 kW, a spurious channel #4 high power scram occurred. No actual high power was indicated on any other instrumentation. The problem was determined to be in the channel #4 range switch. This switch was replaced and tested satisfactorily and the reactor was then returned to normal operation.

Major maintenance items for the month included: replacing the intermediate range monitor (channel #2) DC amplifier; replacing the Gamma Metrics (SRM/IRM) detector and cables; replacing the intermediate range monitor (channel #2) detector; replacing (twice) the wide range monitor (channel #4) picoammeter; replacing the inboard and outboard motor bearings and the inboard pillow block bearing for containment ventilation supply fan (SF-2); replacing the pool outlet temperature (RTD 001C) millivolt transmitter; replacing primary pump 501B motor; replacing wide range monitor (channel A4) range switch.

UNSCHEDULED SHUTDOWNS i .

Date HQ. 'D31g Cause 01/05/97 1055 Scram Loss of Electrical Power 01/06/97 1056 Manual Scram IRM Detector Failure

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01/07/97 1057 Scram Spurious WRM High Power i '

01/07/97 1058 Scram Spurious WRM High Power

! 01/26/97 1059 Manual Rod Run-In Pool Temperature Indication 4

} 01/29/97 1060 Scram Primary Pump Motor Failure 01/29/97 1061 Scram Spurious; WRM Range Switch i

OPERATION

SUMMARY

HOURS OPERATED THIS PERIOD 622 TOTAL HOURS OPERATED 201,493 j HOURS AT FULL POWER THIS PERIOD 618 ,

j TOTAL HOURS AT FULL POWER 198,446 INTEGRATED POWER THIS PERIOD 258 MWD TOTAL INTEGRATED POWER 76,835 MWD MAINTENANCE ACTIVITIES 01/05/97 Refueled - removed core 96-56, loaded core 96-57. Replaced channel #2 (intermediate '

range monitor) DC amplifier.

01/06/97 Replaced Gamma Metrics (SRM and IRM) detector and cables; replaced channel #2 (IRM) detector. ,

01/07/97 Replaced channel #4 (wide range monitor) piconmmeter; removed, cleaned, and reinstalled WRM range switch.

01/13/97 Refueled - removed core 97-1, loaded core 97-2.

01/16/97 Refueled - removed core 97-2, loaded core 97-3.

01/21/97 Refueled - removed core 97 3, loaded core 97-4.

01/22/97 Replaced the inboard motor bearing on containment ventilation supply fan #2 (SP-2).

01/26/97 Refueled - removed core 97-4, loaded core 97-5. Replaced pool outlet temperature millivolt transmitter.

01/27/97 Refueled - removed core 97-5, loaded core 97-6. Replaced the outboard motor bearing on SF-2; replaced the WRM piconmmeter.

01/29/97 Refueled - removed core 97-6, loaded core 97-7. Replaced inboard pillow block bearing on SP-2; replaced WRM range switch.

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