Abstract: A sliding bearing assembly excellent in fretting resistance which comprises a sliding bearing and a housing, the sliding bearing having a bearing alloy layer in the internal surface of its backing metal layer and the internal surface of the housing being fitted with the sliding bearing, wherein a phosphate film is formed on the back of the backing metal layer of the sliding bearing, the phosphate film being composed of needle crystals or columnar crystals which have a particle size of not more than 30 .mu.m when observed from the back of the backing metal layer.

Abstract: A multichamber type fluid bed reaction apparatus has a series of chambers formed by dividing the fluid bed part and the wind box part thereof with particular walls. Each reaction chamber is supplied with a reaction gas whose composition, flow amount and temperature can be selected arbitrarily. A fluid bed, a moving bed or a fixed bed may be used in each divided chamber. Regulation of particle formation, gas-particle reaction and amount of particles transferring between the chambers results in an improvement of efficiency and a simplification of the apparatus.

Abstract: A process for converting UF.sub.6 gas into UO.sub.2 powder comprising blowing UF.sub.6 gas and steam into a fluid bed to produce UO.sub.2 F.sub.2 particle, hydrating and dehydrating the UO.sub.2 F.sub.2 particle to UO.sub.2 F.sub.2 powder, and defluorinating and reducing the UO.sub.2 F.sub.2 powder to UO.sub.2 powder. The UO.sub.2 powder is suitable for manufacturing a reactor fuel owing to its high activity, low remaining fluorine amount and excellent fluidity.

Abstract: A process for conversion of gaseous UF.sub.6 to UO.sub.2 powders by using a fluidized bed reaction apparatus comprising pyrohydrolizing gaseous UF.sub.6 and steam to obtain UO.sub.2 F.sub.2 particles, hydrating and dehydrating the UO.sub.2 F.sub.2 particles to UO.sub.2 F.sub.2 anhydride and reducing the UO.sub.2 F.sub.2 anhydride to UO.sub.2 powders. The obtained UO.sub.2 powders are suitable for production of nuclear fuels in power plant owing to its good ceramic properties, low fluorine contents and free flowability.