Conceptual design study of small-sized high temperature gas-cooled reactor for developing countries, 2; Nuclear and thermal design

Goto, Minoru  ; Inaba, Yoshitomo  ; Fukaya, Yuji   ; Ohashi, Hirofumi ; Tachibana, Yukio ; Nakano, Masaaki*; Tanabe, Kenichi*

Japan Atomic Energy Agency (JAEA) has started a conceptual design of a small-sized HTGR with 50 MW thermal power (HTR50S). It is a first-of-a-kind commercial or demonstration plant of a small-sized HTGR to be deployed in developing countries in the 2020s. The design policy of the HTR50S is to construct it without development of new technologies as possible, which require additional demonstration tests, to suppress the construction cost and deploy it in 2020s. Accordingly, the nuclear and thermal design of the HTR50S was performed by upgrading the proven design technology of the High Temperature Engineering Test Reactor (HTTR). We challenged to increase the power density and decrease the number of the fuel enrichments compared with the HTTR. Additionally, we challenges the nuclear and thermal design for effective utilization of uranium by utilizing high burn-up fuel and axial fuel shuffling.