The diagram shows how steam is created with the help of a gas cooled nuclear reactor.
Overall, the gas cooled nuclear reactor has two ducts with each different temperature. The lower part of the gas cooled nuclear reactor is where the cool gas duct is found while the upper part is the duct for hot gas.
The reactor covered by a concrete shield converts cool gas into hot gas. First, cool gas enters the reactor. Water is the one used to maintain the cool gas. It then goes through the pressure vessel with the help of gas blower. Inside the pressure vessel, there are graphite moderators filled with uranium fuel elements. There is also boron control rods and charge tubes which is use for loading the fuel elements.
The charge tubes and boron control rods are responsible in the production of hot gas. The hot gas pass through another duct which makes the water into steam. The steam created is then used for turbo alternator.