Using the External Gelation Sol-gel Method to create Cerium Uranium Oxides as Potential Surrogates for Americium Uranium Oxides in the Context of European Radioisotope Power Systems

Watkinson, E. J. and Wilbraham, R. and Sarsfield, M. J. and Boxall, C. and Ambrosi, R. M. (2024) Using the External Gelation Sol-gel Method to create Cerium Uranium Oxides as Potential Surrogates for Americium Uranium Oxides in the Context of European Radioisotope Power Systems. In: Proceedings of Nuclear and Emerging Technologies for Space, NETS 2024 :. Proceedings of Nuclear and Emerging Technologies for Space, NETS 2024 . American Nuclear Society, USA, pp. 507-511. ISBN 9780894487989

Abstract

European radioisotope power systems (RPS) for space designed by the University of Leicester will use 241Am-U oxide fuel. The UK’s National Nuclear Laboratory (NNL) is leading the fuel’s research and a Ce-U oxide research programme for the RPS programme for the European Space Agency. Ce-U oxides are being considered as surrogates for the Am-U oxides. One of the objectives of the research programme is to make Ce-U oxides with a range of U/(Ce+U) atomic ratios via two different routes, namely, external gelation sol-gel and oxalate precipitation, and to compare the homogeneity of these products. The lower the uranium fraction in the fuel, the greater the thermal power density of the fuel, and the greater the power output for the RPSs. In this paper, we describe the production and analysis of cerium uranium oxides via the external gelation sol-gel route. Specifically, the results for the production of a Ce0.95U0.05 oxide target are presented. A complimentary study by Lancaster University by Jones et al. (NETS 2024) outlines an equivalent investigation via the oxalate precipitation route. The oxides produced by sol-gel and oxalate precipitation routes of varying Ce/(U+Ce) compositions are being used as feedstocks by University of Manchester for sintering studies (Harris and Ragnauth, NETS 2024). This paper presents the production of the sol-gel material and some of its characterisation.