On-going R&D program at JAEA on the Advanced Technology Fuels; An Update on the Cr-coated Zry cladding research

Mohamad, A. B. ; Yamashita, Shinichiro   ; Nemoto, Yoshiyuki  ; Abe, Yosuke  ; Pham, V. H.   ; Ioka, Ikuo  ; Soma, Yasutaka   ; Ishijima, Yasuhiro ; Sato, Tomonori  ; Rizaal, M.   ; Miwa, Shuhei  ; Nakajima, Kunihisa  ; Kaji, Yoshiyuki  

In parallel with the Advanced Technology Fuel (ATF) development program in Japan, Japan Atomic Energy Agency has established an R&D program on the ATF to provide more scientific support to the ATF fuel vendors in Japan. Based on the identified phenomenological issues, the R&D program covers the issues mainly on the light water reactors conditions such as normal operation, loss of coolant accident, beyond design basis accident, and severe accident. The R&D program such as irradiation test, corrosion test, LOCA test, and etc. are proposed. By acquiring the data from the experiment, the final goal is to implement the experimental data and model into the simulation code in order to predict the fuel performance behaviour at high burn-up. In 2024 TOPFUEL, the introduction of the R&D has been presented. In 2025, the update on the Cr-coated research to simulate normal operation and accident conditions will be given. For example, tests are currently underway to understand the in-reactor environment, such as ion irradiation, gamma irradiation and proton irradiation tests. In addition, a loss-of-coolant accident is being simulated for accident conditions, and the chemical effects of fission products on the cladding are being studied.