Abstract: For the operation of material-test-reactors, recently there have been considered fuels having lower degrees of enrichment in U-235. For this purpose, there is needed U.sub.3 O.sub.8 powder having a crystal size of 40 to 90 .mu.m, which is producible economically and in whose production there is developed as little secondary waste as possible and a pore-free product. For this purpose, uranium compounds of the stage of oxidation +4 to +6 are calcined in an oxygen containing atmosphere whereby the calcining is carried out above 1250.degree. C. in an atmosphere containing more than 30 volume % oxygen.

Abstract: A process and apparatus for the production of pourable, directly compactable uranium dioxide powder by continuous precipitation of uranium peroxide from a stirred uranyl nitrate solution at a pH of 1-2.5 with hydrogen peroxide, calcining of the peroxide at 500.degree.-800.degree. C. and subsequent reduction at 550.degree.-750.degree. C. The precipitation solution contains 70-150 g/l of uranium and 0.80 g/l of ammonium nitrate and is treated with 15-20% aqueous hydrogen peroxide solution in the ratio of U:H.sub.2 O.sub.2 from 1:1.5 to 1:3 and there is led through the solution a mixture of ammonia and air having an air-ammonia volume ratio of 1:0.3-0.6.

Abstract: Uranium hexafluoride having a high U-235 content is driven out of a transportation container by heating in a correspondingly heated container using a halogenated hydrogen free organic liquid as the heating medium. There is also provided an apparatus for carrying out the process comprising a container having a reflux condenser and an insert for holding the transportation container closed at the bottom by condensate outlet.

Abstract: There is provided a process for the production of pourable, directly compactable uranium dioxide powder by continuous precipitation of uranium peroxide from a stirred uranyl nitrate solution at a pH of 1 - 2.5 with hydrogen peroxide, calcining of the peroxide at 500.degree.- 800.degree. C. and subsequent reduction at 550.degree.- 750.degree. C. The precipitation solution contains 70 - 150 g/l of uranium and 0.80 g/l of ammonium nitrate and is treated with 15 - 20% aqueous hydrogen peroxide solution in the ratio of U:H.sub.2 O.sub.2 from 1:1.5 to 1:3 and there is led through the solution a mixture of ammonia and air having an air-ammonia volume ratio of 1:0.3 - 0.6. An apparatus for carrying out the process is also described. SUBACKGROUND OF THE INVENTIONThe present invention is directed to a process and apparatus for the production of directly pressable (moldable) uranium dioxide powder from uranium peroxide (UO.sub.4.xH.sub.

Abstract: There is provided a process for working up and returning without lost waste into the process of casting kernels of uranium-thorium oxide by dissolving the wastes in a nitric acid-hydrofluoric acid mixture and neutralizing the strongly acid solution before the addition to the casting solution. The strong nitric acid solution is evaporated up to the appearance of nitrous gas, the residue diluted with water and this solution brought to a pH of 2.5 to 3.5 with ammonia at a temperature below 40.degree. C.