Abstract
This is a brief summary of (a) fundamental characteristics of HTGRs, of small and modular type especially, on inherent or passive safety, economy to be attained backed up by the safety, nuclear non-proliferation, and wide range of utilizations including electricity and heat generations, (b) recent international HTGR development trends centering to South African PBMR and US-Russian GT-MHR Commercialization Programs, where the positive and challenging activities by the promotors and the affirmative responces by many countries including US, Europe and developing countries, are of value of attention.
