Direct Air Cycle Reactor Development at the General Electric's Lockland, Ohio, plant are well into the hardware stage, and fuel elements are being fabricated for the reactor core which will be used in the Heat Transfer Reactor Experiment (HTRE) next year. The schedule calls for installation of this core, with a rating of 20 MW of heat, in the Core Test Facility at Arco late in 1955. The next step is a 40 MW reactor, of the physical dimensions which would go into an aircraft, in late 1956 or early 1957, Following this, a first ground-test prototype is scheduled for 1958 and probably a second one in 1959. By 1960 they hope to have a nuclear power plant suitable for flight testing. This would probably be in the range of 160 MW. G.E.'s concept of the propulsion cycle involves blowing air from a compressor with a 14-to-l compression-ratio through the reactor, where it is heated to about 1700°F and then enters the turbine. eee weeteee GD DS OR SPs sible turbine inlet temperatures are 1700°F.) (Present maximum permis- Chemical fuel is used in an after-burner when high power is needed for take-off, sprint, etc. Chemical fuel may also be bled in between reactor and turbine as desired. (Such uses of chemical fuel are also applicable in the sodium-cooled system.) A typical study results in an airplane of 435,000 lbs gross weight, containing 106,000 lbs of chemical fuel and 170,000 lbs for reactors, engines, reactor shield and crew shield. The shields themselves total about 100,000 lbs. A reactor might feed more than one engine, and some of the engines might be only chemically-fueled. The fuel elements for the Heat Transfer Reactor Experiment are made by powder metallurgy as a ribbon in which grains of UQ5 are sandwiched in