Current status and future prospect of light water reactor accident-tolerant fuels R&D in Japan

Yamashita, Shinichiro   ; Ioka, Ikuo  ; Nemoto, Yoshiyuki  ; Kawanishi, Tomohiro; Kurata, Masaki ; Kaji, Yoshiyuki  ; Fukahori, Tokio  ; Nozawa, Takashi*; Sato, Daiki*; Murakami, Nozomu*; Sato, Hisaki*; Kondo, Takao*; Sakamoto, Kan*; Kusagaya, Kazuyuki*; Ukai, Shigeharu*; Kimura, Akihiko*; Yamaji, Akifumi*

Research and development (R&D) program for establishing technical basis of ATFs for light water reactor (LWR) started in 2015. Since then the R&D is being conducted in cooperation with power plant providers, fuel venders, research institutes and universities for making the most use of the experiences in R&D, practical design, and evaluations of fuels and cores of commercial LWRs. Among currently explored ATF candidate materials in the program, silicon carbide composite reinforced by SiC fiber (SiC/SiC) and FeCrAl steel strengthened by dispersion of fine oxide particles (FeCrAl-ODS) offer several attractive features including the remarkable high temperature capabilities and the slow kinetics of steam oxidation reactions. This presentation will give an overview of the progress in ATF development and review the current status of data availability and integrity for the properties and behaviors of ATF candidate materials, followed by discussion on the primary differences from zirconium alloy in the behaviors in the severe accident scenarios. Finally, subjects to be solved for practical use of ATF will be summarized.