Studies with plutonium-fuelled cores in the zero-energy, high-temperature nuclear reactor 'zenith'

This paper describes a series of experiments carried out with plutonium fuel in the heated zero-power reactor zenith, with the aim of testing current theoretical methods, with particular reference to excess reactivity, temperature coefficients, differential spectrum and reaction-rate distributions. Two cores of widely different fissile/moderator atom ratios were loaded in order to test the theory under significantly varied spectrum conditions. The general agreement is comparable with that found for the 235U cores previously investigated. © 1966.