Measurement and analysis of reaction rates in radial breeder regions of Zebra Assembly 13

Foil activation techniques have been used to study the major contributions of the power output from the radial breeder region of an operating mock-up of the Prototype Fast Reactor. Three breeder configurations have been investigated; a clean uranium-oxide breeder, an irradiated uranium-oxide breeder, and a uranium-carbide breeder. Predictions of the power distributions have been made using FGL5 data with both diffusion and transport theory models. It has been shown that the standard diffusion theory treatment may lead to errors of about 10% in breeder power relative to that in the core but that significant improvements are obtained by the use of transport theory. (author)