Inhomogenous type nuclear reactor

Purpose: To secure the entire reactor core safety by improving fuel pins and automatically suppress the power up. Constitution: The inner diameter of a fuel can is reduced at the lowermost end of piled fuel pellets for use in the internal blanket of an inhomogenous type nuclear reactor and supported so as not to move downwardly. Further, all or a portion of piled reactor core fuel pellets and blanket fuel pellets are made as hollow pellets formed with vacant holes in the axial direction at the center thereof. If the reactor power rises abnormally by some or other reasons, the temperature at the central portion of the reactor core is elevated. Due to the temperature elevation, the periphery of the central cavities of the reactor core fuel pellets (hollow pellets) below the internal blanket fuel pellets are melted, and the nuclear fission reaction is automatically stopped and suppressed by the gravitational downward movement of nuclear fuel material by melting through the vacant holes. (Kamimura, M.)