THERMODYNAMIC AND PHASE-DIAGRAM STUDIES ON METAL-TELLURIUM SYSTEMS EMPLOYING KNUDSEN EFFUSION MASS-SPECTROMETRY

Reliable thermodynamic and phase diagram data are essential to underst and the behaviour of fuels in a nuclear reactor, The fission product t ellurium is believed to play a significant role in fuel-cladding inter action in the oxide-fuelled fast breeder reactor, In order to assess i ts role in the fuel-cladding interaction, a systematic study of the bi nary systems of Te and a cladding component (Fe, Cr, Ni, Mo and Mn) wa s taken up in our laboratory, The Knudsen effusion mass spectrometric technique was employed very effectively to obtain both thermodynamic a nd phase diagram information, This paper summarizes the results obtain ed from these studies, Most of these tellurides exhibit non stoichiome try, 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 determine d were employed to calculate the threshold tellurium potential require d for the formation of metal tellurides from the fuel-cladding interac tion and compared with the equilibrium tellurium potential that is Lik ely to be present in the fuel-cladding gap in a fast breeder reactor.