Processes for Recovery of Uranium and Thorium From Graphite-Base Fuel Elements. Part Ii

Nuclear Fuels and Reprocessing Technologies: A U.S. Perspective

“…Once the fuel kernels are exposed, methods of extracting the fissile materials include traditional aqueous digestion, supercritical CO 2 solvent extraction (as the carrier for an appropriate extractant), and molten salt dissolution. [628][629][630][631][632][633][634][635][636][637][638]…”

Analysis of Combustion of Graphite-Uranium Fuels in a Fixed Bed or Moving Bed

“…The first step in a proposed processing method for recovery * of uranium from graphite-uranium fuels consists of oxidation of the fuel by oxygen to volatilize the carbon (77). Residue ash from the combustion step can be treated in a variety of ways to recover and purify the uranium (3,77). The combustion step may be carried out by bringing the solid fuel in a fixed or moving bed in contact with a stream of oxygen-bearing gas in a tubular or annular reactor.…”

“…The small-scale combustion of graphite for recovering the included uranium has been a successful processing method in U. S. Atomic Energy Commission facilities for several years (7), and the feasibility of engineering-scale graphite-uranium fuel combustion in fixed beds has been demonstrated at Oak Ridge National Laboratory, where the Ultra High Temperature Reactor Experiment (UHTREX) type of fuels has been burned successfully (3,6).…”

Mellitic Acid from the Oxidation of Graphite with 90% Nitric Acid.

“…SeVERAL METHODS utilizing nitric acid for the processing of graphite-matrix nuclear reactor fuels have been studied (1,2,5). Generally, 4 to 15M HN03 is employed; however, in one of these procedures (2) the fuel is simultaneously disintegrated and leached with boiling 90% HN03.…”