Progress on ATF development of SiC for LWR

Since 2011, Toshiba has been participating in a study whose objective is the commercial utilization of SiC instead of Zircaloy as LWR fuel material. During the period (Phase-1) from 2012 to 2015, feasibility studies on material design and fabrication were performed. This paper reports the principal results of a comprehensive feasibility study on SiC involving experiments and trial fabrication in terms of material properties, core and fuel design, and analytical simulation for safety analysis. The principal results are summarized as follows. First, the fabrication trials for the reduced scales of channel box and cladding have been successfully performed. Secondly, with regard to fuel rod performance analysis, hoop stress during normal operation may be a potential issue in fuel mechanical design as it is relatively high. Thirdly, with regard to safety analysis, the hydrogen generation of SiC fuel tends to decrease significantly compared with that of Zircaloy fuel