METHOD FOR PREPARING URANIUM DIOXIDE POWDER-BASE TABLETTED FUEL

摘要

FIELD: nuclear fuels, chemical technology.;SUBSTANCE: invention relates to a method for preparing FE for nuclear power plants. Method for preparing uranium dioxide powder used in producing tabletted fuel with addition of liquid lubricant involves evaporation and hydrolysis of uranium hexafluoride, dissolving uranium lower oxide-oxide and uranium-containing waste, extraction and re-extraction of uranium, precipitation of ammonium polyuranate with maintaining pH value in precipitation step 6.6, not less, followed by filtration, drying, thermal decomposition and reduction of a calcined product at temperature 660-730°C. In process for preparing uranium dioxide powder uranium is re-extracted with solution of mineral or organic acids or their ammonium salts prepared by using purified water with specific resistance 20000 Ohm/cm, not less. Precipitation of ammonium polyuranate is carried out at maintaining temperature 60 ± 5°C and maintaining based on such conditions the settling rate of ammonium polyuranate as 10 mm/min, not above. Invention provides the development of a method for preparing uranium dioxide powders of nuclear purity and ceramic sort useful for producing fuel tablets possessing higher quality. Invention can be used in technology for producing nuclear ceramic fuel with addition of liquid lubricant.;EFFECT: improved preparing method.;9 cl, 1 tbl, 1 ex