CRITICAL EXPERIMENT OF THORIUM LOADED THERMAL CORES AT KUCA (1) A NEW CRITICAL EXPERIMENT OF THORIUM LOADED CORE WITH HARDER NEUTRON SPECTRUM IN KUCATadafumi Sano, Jun-ichi Hori, Jeaong Lee, Yoshiyuki Takahashi, Kazuki Takahashi and Hironobu UnesakiEPJ Web Conf., 247 (2021) 09013DOI: https://doi.org/10.1051/epjconf/202124709013