Reliable thermodynamic and phase diagram data are essential to understand the behaviour of fuels in a nuclear reactor. The fission product tellurium is believed to play a significant role in fuel-cladding interaction in the oxide-fuelled fast breeder reactor. In order to assess its role in the fuel-cladding interaction, a systematic study of the binary systems of Te and a cladding component (Fe, Cr, Ni, Mo and Mn) was taken up in our laboratory.
The Knudsen effusion mass spectrometric technique was employed very effectively to obtain both thermodynamic and phase diagram information. This paper summarizes the results obtained from these studies. Most of these tellurides exhibit non stoichiometry. Making use of the property of preferential evaporation of one of the components from these metal tellurides, the homogeneity ranges of most of these phases were determined. The thermodynamic data determined were employed to calculate the threshold tellurium potential required for the formation of metal tellurides from the fuelcladding interaction and compared with the equilibrium tellurium potential that is likely to be present in the fuel-cladding gap in a fast breeder reactor. 7.5 mm; 0.d. 10.0 mm; height 10.0 mm; orifice diameter