THE BMI-16 RECIRCULATING GAS LOOP INSTALLED AT THE ETR

A developmental program was conducted to provide and in-pile loop facility for use in evaluating gas-cooledreactor fuel asubassemblies. The program included the design, construction, and installation of a recirculating gas loop which is located in a 6 by 6-in. facility in the aluminum reflector of the ETR. The loop system was designed to recirculate the primary nitrogen coolant at flow rates up to 0.9 lb per sec and pressures up to 200 psia. It will accept fuel subassmeblies up to 36 in. in length and 2.26 ia. in diameter with specimen power generation up to 150 kw. The maximum coolant temperature at the specimen outlet is set at 1500 deg F. The loop system includes the in-reactor section, the machinery, the control system, and the specimen-handling apparatus. Salient features of the re-ertrant system include an aluminum pressure wall in the in-reactor section, static gas insulation between the reactor coolant and the circulating loop gas, and a controllable rate of heat exchange between the specimen inlet- and specimen outlet-gas channels in sections of concentric countedlow piping. The three blowers in the system feature grease-lubricated bearings and water cooling. The complete system was tested out of pile and is now installed in the ETR. (auth