Experimental Investigations of Additives on Irradiation Performances of Oxide Fuel

The fuel and material tests performed in the Halden reactor are aimed at supporting innovative fuel development which is aimed at improving the fuel cycle by: suppressing fission gas release; reducing pellet-cladding mechanical interaction; improving oxide fuel thermal conductivity; and as a consequence the in-pile fuel performance with burn-up accumulation. In general, all recent developments presented in the Halden experiments are based on the following additives: - Gd neutron absorbing isotopes, which suppress extra reactor reactivity at BOL for prolongation of the fuel cycles in LWRs - chromium oxides and aluminum silicates, which are able to increase fuel grain size during production and suppress fission gas release during irradiation - beryllium oxide, which increases composite oxide fuel thermal conductivity This paper reviews some of the experiments performed in the Halden reactor for understanding the effects of additives on oxide fuel performance during irradiation. The paper also presents future plans for the testing the Halden reactor other innovative fuels with increased tolerance to accident conditions.