METHOD FOR RECOVERING PARTICULAR PARTICLES OF OXIDISABLE NUCLEAR FUEL WASTE IN SINNERABLE FORMATION FROM THE PREPARATION OF NUCLEAR FUEL.

摘要

1,257,327. Processing nuclear fuel. GENERAL ELECTRIC CO. 13 Dec., 1968 [14 Dec., 1967], No. 59522/68. Heading G6R. [Also in Division C1] Reclaimation of hard-sintered nuclear fuel scrap material is effected by feeding particles of the scrap fuel comprising UO 2 , PuO 2 , ThO 2 or any mixture thereof into a fluidized bed reactor; feeding an oxidizing gas, e.g. air, at a temperature of 400‹ to 600‹ F. into the lower end of the reactor, in a quantity sufficient to supply at least twice the stoichiometric amount of oxygen required to completely oxidize the scrap material; maintaining the reactor at 800‹ to 1300‹ F. whereby the fuel particles are continuously simultaneously oxidized, e.g. UO 2 to U 3 O 8 , and comminuted; controlling the flow of gas into the reactor so that the largest particles are not fluidized, medium sized particles are fluidized and the smallest particles are carried out of the top of the reactor; and recovering the smallest particles. The higher oxides thus produced are then reduced back to the original dioxide state by a reducing gas, e.g. H 2 or dissociated ammonia, at elevated temperature, e.g. 1150‹ to 1350‹ F. In the example UO 2 containing 2% USP235/SP and 98% USP238/SP is processed. Specific dimensions for a suitable fluidized bed reactor are given.