A new design of composite fuel with Zr-coated TRISO particles dispersed in metal matrix

With the development of advanced reactors, it is critical to improve the safety of nuclear reactors. Safety primarily depends on the ability to block fission products and the ability to discharge decay heat of fuel elements. To enhance the ability to retain the release of fission products and achieve high thermal conductivity, a novel fuel pellet was developed, consisting of zirconium (Zr)-coated TRISO particles embedded in a zirconium metal matrix. The zirconium coating was deposited via fluidized-bed chemical vapor deposition (FB-CVD), and the deposition mechanism of Zr coating via FB-CVD was proposed. The consolidation process of Zr-coated TRISO particles in the Zr matrix was achieved via spark plasma sintering (SPS). The microstructure and mechanical properties of Zr coating and the pellet were investigated via SEM and nanoindenter. The results proved the effectiveness of zirconium coating in preventing TRISO fuel particles from contact and cracking during sintering.

Automated summary

With the development of advanced reactors, improving the safety of nuclear reactors is crucial. This study developed a novel fuel pellet with zirconium-coated TRISO particles embedded in a zirconium metal matrix to enhance the ability to retain the release of fission products and achieve high thermal conductivity. The zirconium coating was deposited using fluidized-bed chemical vapor deposition (FB-CVD), and the consolidation process was achieved via spark plasma sintering (SPS). The effectiveness of the zirconium coating in preventing particle contact and cracking during sintering was confirmed through microstructure and mechanical property investigations.