EMBALLAGE ET ETUI DE TRANSPORT D'ASSEMBLAGES IRRADIES DE SURVEILLANCE DU RNR DE CREYS-MALVILLE

Certain irradiated assemblies from the Creys-Malville fast reactor are transported to hot cells for examination. With a maximum decay power of 10 kW, these assemblies are transported under liquid sodium in order to spread out the heat flux since the power is actually released over only part of the length. The requirement of transport under sodium and the constraints imposed by the examination of the fuel following transport have required certain special design characteristics. The fuel assembly is first conditioned in a tightly sealed shroud containing sodium. The shroud is then inserted into the package. The body of the package has a single compartment and consists of a thick steel cylindrical shell, the inside of which is lined by a stain· less steel tube. Two annular chambers at the extremities of the cylinder contain heat insulation to prevent solidification of sodium in the regions distant from the fissile part of the assembly where the heat is released. The paper contains a thermal analysis of the package in normal trans· port conditions and in emergency conditions.