Safety design philosophy of Hydrogen Cogeneration High Temperature Gas Cooled Reactor (GTHTR300C)

Nishihara, Tetsuo ; Ohashi, Kazutaka; Murakami, Tomoyuki; Kunitomi, Kazuhiko 

A design study of the hydrogen cogeneration high temperature gas cooled reactor (GTHTR300C) based on the achievement of gas turbine high temperature reactor design has been carried out in Japan Atomic Energy Agency. The safety design philosophy of the GTHTR300C to keep hydrogen economy and to attract a lot of interest from non nuclear industries is discussed. The hydrogen production system which is coupled to the secondary helium loop of the intermediate heat exchanger installed upstream of the gas turbine system shall be designed as a non nuclear graded system. General nuclear safety shall be ensured by the items installed in the reactor system. Functions of secondary helium loop which are primary helium cooling and pressure control and purification of secondary helium are required to continue normal operation. Means to maintain these functions are proposed by using equipment of the reactor system and the gas turbine system without the hydrogen production system so that the power generation can continue independently of operational state of the hydrogen production system. Means of protection against external event of flammable and/or toxic gas release are also considered.