Materials that exhibit high oxide ion conductivity are of interest with a view to their application in solid oxide fuel cells, gas sensors and gas separation membranes. A study of oxide ion distribution in a highly conducting neodymium substituted bismuth oxide based solid electrolyte system is proposed. This system exhibits a layered structure and previous studies have revealed significant positional disorder in the oxide ions close to the inter-layer space. This study aims to use total neutron scattering analysis of representative compositions in the bismuth neodymium oxide system to examine the compositional and thermal variation of oxide ion distribution, including Reverse Monte Carlo analysis of total neutron scattering data. These studies will be combined with parallel electrical and modelling studies to reveal details of the conductivity mechanism in this system.