REACTOR PHYSICS EXPERIMENT IN A GRAPHITE-MODERATION SYSTEM FOR HTGRY. Fukaya, M. Goto, S. Nakagawa, K. Nakajima, K. Takahashi, A. Sakon, T. Sano and K. HashimotoEPJ Web Conf., 247 (2021) 09017DOI: https://doi.org/10.1051/epjconf/202124709017