Pyrohydrolyse von Karbid-Kernbrennstoffen

摘要

Carbides of uranium and thorium are hydrolysed by contacting with oxygen free steam at from 700 DEG C. to a temperature below that at which the resultant metal oxide sinters, e.g. not exceeding 1150 DEG C., to produce a carbon-free oxide powder. The carbide may be in the form of nuclear fuel elements in which the carbide is encased in a protective metal cladding, this is partially removed to expose the carbide and steam at 700 DEG to 800 DEG C. is used. Alternatively the carbide nuclear fuel may be carbon coated or dispersed in a graphite matrix in which case steam at 1000 DEG to 1150 DEG C. is necessary for complete conversion to the oxide. The product is a free-running, carbon-free oxide powder which is suitable for the partition of unburned fuel, transmutation and fission products by solvent extraction or distillation processes.