GB1229388A - - Google Patents

Abstract

1,229,388. Fuel elements. BELGONUCLEAIRE S.A. 2 April, 1970 [17 April, 1969], No. 15642/70. Heading G6C. In the manufacture of a nuclear fuel element comprising a graphite container at least partially filled with fuel particles mixed with a binder paste, the particles and the paste are introduced into the container which is subjected to centrifugation about an axis differing from that of the container, whereby the particles and paste are intimately dispersed. A container 4 made up of two concentric graphite tubes 1, 2 is filled with a paste 5 formed of graphite powder, phenolic resin and ethyl alcohol. The container 4 is then fixed within a metal casing 6 hung from a centrifuge rotating assembly 9 and a funnel 10 is fitted on the container. Spherical particles 11 are then poured into the funnel, these particles comprising U0 2 cores covered in succession with layers of pyrolytic carbon, silicon carbide, high density pyrolytic carbon and low density pyrolytic carbon. The whole assembly is rotated at 3000 r.p.m. while the particles 11 penetrate gradually into the paste 5 which is thus forced towards the entrance of the container 4. At the end of this operation a substantially homogeneous distribution of the fuel particles in the paste is reached. The container 6 is then unloaded from the casing 6 and heat treated to polymerize then carbonize the resin and finally to free the container from gas. Alternatively, the particles are first introduced into the container and the paste then added, or a mixture of particles and paste is loaded in the container.