MEASUREMENTS AND ANALYSIS OF FISSION RATES N A ZEBRA MOCK-UP OF THE PROTOTYPE FAST REACTOR

摘要

The Zebra multi-chamber scanning system has been used to map the fission distributions in an operating-mock-up of the Prototype Fast Reactor. The core contained five control rods at a range of different insertions, together with other singularities representing sodium-filled channels, experimental subassemblies, in-core breeders etc. Cross-core tilts approaching 40％ were observed for asymmetric rod patterns. The measured distributions are shown to be in good agreement with the predictions of three-dimensional diffusion-theory calculations, the standard deviation of calculation/experiment being about 1％.