The conversion of UNH to UF4 and UF6, utilizing moving-bed techniques, is being studied; sufficient progress has been made that an evaluation of the process is warranted. The procedures under study, the Fluorox Process, have three major advantages: (1) substitution of HF for high-cost fluorine, (2) considerable reduction in HF requirements, and (3) marked reduction in plant-size and mechanical complexity.

Results of four experiemental runs in the Fluorox fluidized bed reactor system are reported. The engineering feasibility of UF6 production from UF4 by use of dry air of O2, 2UF4 + O2 = UF6 + UO2F2, in an Inconel fluidized bed reactor at 800-850°C was demonstrated in two experimental tests in which greater than 90% of the theoretical amount of UF6 was collected or measured. Two runs made with crude UF4 (produced from unpurified mill concentrate) as the feed material, showed that UF6 could be produced at 700-725°C but corrosion on Inconel was prohibitive.

At the present time, plants in the 100-500Mv size range are more numerous and carry the greatest portion (over 50%) of the total steam-electric plant load in the U.S. utilities industry. The contribution of plants of over 1,000-Mv capacity is increasing more rapidly than any other size clarification and at present represents about 10% of the total capacity. By 1962 the TVA will have six plants with capacities of over 1,000-Mv. The largest steam-electric plant in the U.S. is the TVA plant at Kingston, Tenn., with a nameplate capacity of 1,440-Mv. Turbine-generator units are also following a trend of ever-increasing size. In present construction, the 150-200 Mv size range for units is the most common and represents the greatest contribution to capacity. Two units of 500-Mv nameplate rating each, the largest in the U.S., are on order by the TVA, and an 800 Mv unit is contemplated.