SHS Preparation and β-Irradiation Stability of Sr-Doped Graphite

In order to study the treatment of simulated radioactive graphite contains 90Sr by SHS and its β-irradiation stability, waste forms were prepared in accordance with the reaction 3C + 4Al + 3TiO2 = 2Al2O3 + 3TiC+Q, by self-designed SHS equipment. Then the β-ray irradiation experiments were done at dose of 106Gy to evaluate its radiation resistance. The phase composition and morphology of the prepared waste forms before and after irradiation were characterized by X-ray diffractometer (XRD) and scanning electron microscope (SEM). The XRD results indicated that the major composition of the waste forms were Al2O3, TiC, C, TiO2 and AlN after reaction in atmosphere, and the SrO solid solubility could be up to 8wt%. It was found that the surface morphology of waste forms were mostly plate-shaped and mainly in about 10μm. The structure and microscopic morphology of waste forms didn't change significantly before and after irradiation according to the XRD spectra, SEM photos. Moreover, the calculated cell parameters results suggested that the lattice parameters of the main phase (TiC, Al2O3) changed about 10-3~10-2nm after irradiation, and the degree of changes in cell volume was about 10-4~10-3nm3 magnitude. The simulated 90SrO–containing radioactive graphite waste forms showed a certain β-ray radiation resistance.