Fundamental research program on zircalloy with accident tolerance

Mohamad, A. B. ; Soma, Yasutaka   ; Nemoto, Yoshiyuki  ; Abe, Yosuke  ; Ioka, Ikuo  ; Sato, Tomonori  ; Ishijima, Yasuhiro ; Miwa, Shuhei  ; Nakajima, Kunihisa  ; Kaji, Yoshiyuki  ; Yamashita, Shinichiro   ; Osaka, Masahiko  

Japan Atomic Energy Agency (JAEA) has launched fundamental researches on zircalloy with accident tolerance since 2019. The main purposes of the fundamental researches are to deepen the understanding of the zircalloy behavior under long-term normal operation or Loss of Coolant Accident (LOCA), beyond design basis accident (B-DBA) and severe accident (SA) conditions, and to support the implementation of Cr-coated zircalloy which is being developed by Japanese vendor. JAEA has also been conducted basic technology developments which is necessary for the understanding of the behavior of accident tolerant coated-zircalloy under normal operation, LOCA, B-DBA and SA conditions. For example, the ion irradiation technique combined with light water reactor (LWR) coolant conditions is being developed to simulate the normal operation condition. In addition, to understand LOCA phenomena, the results obtained from the LOCA test are implemented in the machine learning to understand in more detail the cladding fracture and ballooning. Furthermore, a separate effect test, such as the high temperature oxidation test, is also carried out. The fission product release during the B-DBA and SA are also included in the research program. The research results obtained by using these basic technologies will be integrated and implemented into the fuel performance analysis code to predict the fuel performance under reactor operating conditions.