An in-Pile Gas-Cooled Loop Installed at the Battelle Research Reactor

A developmental program was conducted to provide a loop facility for use in evaluating fuel specimens for gas-cooled-reactor applications. The program included the design, construction, and operation of a recirculating in-pile loop featuring high-pressure gas as the primary coolant. The loop facility was designed for gas pressures of up to 200 psig and gas-flow rates up to 0.415 lb per sec with nitrogen as the coolant. Design features incorporated into the facility induced the mounting of the complete package'' on the movable bridge at the Battelle Research Reactor (BRR). This provided ease in moving the loop away from the reactor core for service and specimen transfers. The loop design featured an aluminum pressure wall and concentric counterflow gas passages with static-gas insulation adjacent to all pressure walls. The entire circulating system was located beneath the water level of the pool to signed for use at 750 F inlet-gas temperature, and it featured both oil and water cooling. The instmentation was designed to protect personnel and equipment, and to provide information on the specimen during irradiation. The specimen-transfer mechanism was designed to utilize pool-water shielding while moving a dry specimen from the loop cask located approximately 20 ft below the pool surface. The complete loop system was subjected to boih out-of-pile and in-pile evaluation. The blower has operated satisfactorily over 2000 hr and specimen transfers have been effected without water leakage into the loop or transfer cask. (auth