ADVANCED COATINGS FOR HTGR FUEL-PARTICLES AGAINST CORROSION OF SIC LAYER

For fuel particles of the high-temperature gas-cooled reactors, three types of new combinations of the coating layers were invented to preve nt the corrosion of the SiC layer by fission products. The idea was th at a layer to trap fission products was added inside the SiC layer of the Triso-coating. Two kinds of materials of SiC and SiC with free car bon were selected as additional layers, The fuel particles with these advanced coatings were fabricated to test the effectiveness of the coa tings in out-of-reactor and irradiation experiments. These experiments showed that the advanced coatings had good irradiation performance an d functioned effectively against corrosion of the SiC layer, although further irradiation tests are needed to completely demonstrate the eff ectiveness of the advanced coatings. (C) 1997 Elsevier Science B.V.