ML20072Q911

Advises That Power Level Increase to 300 Kw,Authorized by Amend 5 to License R-108,issued on 890508,implemented. Neutron Detectors Near Reactor Core Moved to Reflect Higher Max Power Level

ML20072Q911
Person / Time
Site:	Dow Chemical Company
Issue date:	03/14/1991
From:	Kocher C DOW CHEMICAL CO.
To:	Office of Nuclear Reactor Regulation
References
NUDOCS 9103210251
Download: ML20072Q911 (2)

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1602 Building March 14,1991 Director, Office of Nucler. Scactor Regulation U.S. Nuclear Regulatory Co. mission Washington DC 20555 DOW TRIG A RESEARCll REACTOR DOCKET 50 2M Amendment 5 of the Facility Operating License R 108 (8 May 1989) authorized the Dow TRIG A Research Reactor facility to operate at power levels up to 300 kilowatts, an increase from the previously authorized maximum power level of 100 kilowatts.

The power level increase portion of this amendment was delayed until the realization of long-range plans to upgrade the control system for the reactor, %at upgrade is well in hand and the power level increase has been implemented.

This report is intended to satisfy the Aquirements of item 6,6.2.c of the Technical Specifications for this facility (report within 60 days of criticality).

Two r ew standard TRIG A fuel elements were inserted into the core of the reactor, replacing two graphite filled dummy elements in the outer (F) ring of the core, on January 29,1991. Special Experiment 93, approved Ianuary 22,1991, by the Reactor Operations Committee, authorized this modification of the core This resulted in an increase of the core excess from about $1.80 to about

$2.25, conservatively lower than the Technical Specifications maximum core excess limit of $3.00.

He neutron detectors near the core of the reactor were moved to reflect the higher maximum power level and the reactor was operated at a nominal power level of 200 kilowatts January 31,1991, for a thermal calibration The nominal calibration was conservative; the actual thermal power was found to be 182 kilowatts. The neutron detectors were moved to reflect this ca!!bration. His work was authorized by Special Experiment 95, approved by the Reactor Operations Committee January 30, 1991.

During this operation the radiation level at the level of the grid, directly over the core of the reactor, was evaluated using an ion-chamber survey instrument. He radiation dose rate was found to be increased in proportion to the increased power level, as expected. On February 8,1991, the facility Radiation Safety Ofncer performed a survey of the facility while the reactor was operating at 250 kilowatts. Radiation levels within the reactor room, at the control console, outside the confines of the reactor room, and on the roof of the building over the reactor were found to be lower than the limits established for the respectiv areas, and in line with the power level .ncrease.

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Director, Office of Nuclear Reactor Regulation _ 1 March 14,1991 '

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Page 2 Special Experiment 894, approved by the Reactor Operations Committec January 22,1991, authorimi L the irradiation of samples in the lazy susan facility for periods of up to 30 minutes at power levels of up -

- to 300 kilowatts, This authorization has been used a number of times to irradiate samples at power

. levels of up to 270 kilowatts for the purpose of documenting tie safety of this procedure, 'this is similar to the experiments that were performed during the first operation of the reactor in 1967, at power levels of up to 100. kilowatts, and is based on previous measurements made at the G A 250-kilowatt TRIG A; y reactor cartier, Review of the results of this series of experiments will allow the Reactor Operatkms :

Committee to rule that any further similar irradiations are to be considered routine experiments, with tie

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hazards of the procedures well studied and understoodi The results of these experiments indicate that

- such usage produces effects similar to those at lower operating power, and that the samples and -

operating conditions are t.ot significantly more hazardous than observed under the lower operating -

power, Other Special Experiments will be used to evaluate the operation of the reactor at the higher power levels for other experiments already approved for the 100 kilowatt level: use of the pneumatic tube system for delivery of sing!c samples to a core position for irradiation, and for use of the central thimble as a beam tube for neutron radiography in the reactor room, h

hd bb C. W. Kocher !

Reactor Supervisor Analytical Sciences :

_(517)636 0304:

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