Use of thermodesorption spectroscopy for quality control of the nuclear fuel

The possibility of use of number of methods and experimental units for assessment of nuclear fuel quality is studied. The preliminary investigations of gas evolution from uranium dioxide samples, both sintered and non-sintered are carried out, as well as electrophysical characteristics of uranium dioxide were studied. Unit for investigation of gases thermodesorption from solids represents chamber with pumping down system and with control and measuring systems. There is tungsten furnace in chamber for supporting of optimal temperature. Registration of desorption gases is carried out by r-f mass spectrometers M X-7304. The unit is completely automated: the heating rate, temperature, tuning on chosen masses during the experiment have been carried out with help of computer. Thermodesorption curves have been picked off in differential regime and it is characterizing rates of gases evolution like temperature functions. Other unit on the base of factory mass spectrometer MCX-6 was used for non-sintered samples. The unit was modified and supplied by additional system of deviating electrodes. This factor allows to increase sensitivity in to 100 times. The unit allows to receive thermodesorption spectra not only from pellets but and from powders and liquids too. Beside thermodesorption investigations of the electric resistance measuring were carried out. The advantages of using thermodesorption spectroscopy and measuring electric resistance for control of uranium dioxide pellets properties and improvement of technological process of their manufacture are shown. 2 figs