Estimating the Brittle Strength of Nuclear Fuel Material

The development of nuclear energy involves use of promising nitride nuclear fuel in reactors of the 4th generation. This will require improving the fuel production technology as well as its test methods. For estimation of the strength of the nuclear fuel material as well and for further refinement of nuclear fuel test technology we propose to use small discoid samples, similar in shape to the elements of nuclear fuel in the context of ”Brazilian test” (compression applied to disk specimen in the median plane). We present here the results of testing small discoid specimens made of brittle materials such as cast iron and graphite (both being considered as possible model materials for the nuclear fuel). We compared these materials to nuclear fuelitself (as represented by uranium dioxide). In addition the effect of the specimen size on resistance to destruction was investigated. The type of deformation and fracture found in samples made from cast iron suggests that this material cannot be used as a model for the nuclear fuel. At the same time the results obtained in tests on samples composed of graphite ARV-1 were in good agreement with the results oftests on uranium dioxide. Using the data obtained in this study, a calculation formula for determining the strength of the nuclear fuel material based on the “Brazilian test” results is proposed