Strahlenbestaendige Kernbrennstoff-Verbundkoerper mit Graphitmatrix fuer Kernbrennstoffelemente fuer Hochtemperaturreaktoren

摘要

1338146 Fuel elements NUKEMNUKLEARCHEMIE UND-METALLURGIE GmbH 21 April 1971 [22 April 1970] 10346/71 Heading G6C A nuclear fuel body comprises fuel particles, e.g. UO 2 , UC 2 , (Th, U)O 2 or (Th 1 U)C 2 cores coated with pyrolytic carbon and SiC embedded in a graphite or carbon matrix, the matrix consisting of ultra-fine graphite with a grain size of less than 20Á. Optionally, up to 50% by weight of the matrix may consist of carbon powder, e.g. carbon black, with a particle size of less than 1Á in admixture with the graphite. The graphite and carbon powder are quasi-structureless (i.e. without any preferential orientation) in the internal structure of the individual grains and are processed into the fuel body without any preferential orientation. The result is to avoid the pronounced anisotropic dimensional changes which occur in anisotropic graphites, also the anisotropic dimensional changes and damage which occur in so-called isotropic but microscopically still anisotropic graphite bodies, because the graphite or carbon powder used in this invention shows, in the grain itself, hardly any preferential orientation.