Conceptual design study of small-sized high temperature gas-cooled reactor for developing countries, 3; Fuel design

Ueta, Shohei   ; Aihara, Jun ; Mizutani, Yoshitaka; Ohashi, Hirofumi ; Sakaba, Nariaki ; Tachibana, Yukio ; Honda, Masaki*; Tanaka, Hideki*; Furihata, Noboru*

In the small-sized high temperature gas-cooled reactor, the improved fuel of which the burnup is designed over 100 GWd/t is used in order to upgrade economy and to decrease radioactive waste. On the other hand, to attain over three times higher burnup than that of a conventional HTTR fuel, 33 GWd/t, researches and developments of the fuel should be needed with regards to the design preventing the fuel from the failure by internal pressure due to gases in the coated fuel particle, the technologies for fabrication of the improved fuel, and the irradiation test to confirm its integrity under the irradiation. A design work, fabrication tests and a plan of the irradiation test for the improved fuel in order to demonstrate the performance are reported.