Quantitative image analysis of unirradiated fast breeder reactor fuel

Abstract

Three variants of fast breeder reactor fuel, sintered at different temperatures, are examined with the following methods of image analysis: • lateral porosity distribution, • pore size and grain size distribution, • • dependence of the shape on the size of pores and grains. These methods show that, in principle, two types of fuel exist: Type A: sintering temperatures 1610 and 1710°C, porosity distribution relatively homogeneous, bimodal pore size distribution, monomodal grain size distribution. TypeB: sintering temperature 1510°C, porosity distribution more inhomogeneous, trimodal pore size distribution, bimodal grain size distribution. These methods are briefly described and the quantitative results displayed. Using these methods these types of nuclear fuel will be re-examined after in-pile irradiation. The results, which are shown here, can then be correlated with those obtained after irradiation in order to recognize changes in structure dependent on temperature, time and burnup.