Influences of the ZrC coating process and heat treatment on ZrC-coated kernels used as fuel in Pu-burner high temperature gas-cooled reactor in Japan
Aihara, Jun
; Ueta, Shohei
; Honda, Masaki*; Mizuta, Naoki
; Goto, Minoru
; Tachibana, Yukio
; Okamoto, Koji*
The concept of a Pu-burner high temperature gas-cooled reactor (HTGR) has been proposed for purpose of more safely reducing amount of recovered Pu. This concept employs coated fuel particles (CFPs) with ZrC coated PuO
-YSZ kernel and with tristructural (TRISO) coating for very high Pu burn-up and high nuclear proliferation resistance. In this report, we investigate the microstructure of the region that includes the surface of an as-fabricated CeO
-YSZ kernel simulating PuO
-YSZ kernel. We found both Zr-rich grains and Ce-rich grains to be densely distributed in that region including surface of CeO
-YSZ kernel. On the other hand, it has been reported that there was a porous region near surface of the CeO
-YSZ kernel of Batch I. This finding confirms that Ce-rich grains near surface of CeO
-YSZ kernels coated with ZrC layers have been corroded during the deposition of the ZrC layer, whereas the Zr-rich grains were hardly affected.