high-temperature gas-cooled reactor

High-temperature gas-cooled reactors (HTGRs) are a type of nuclear reactor that uses a mixture of graphite and fuel-bearing microspheres as fuel. These reactors utilize helium as a coolant, pressurized to about 100 atmospheres. The high operating temperatures are possible because graphite has a very high sublimation point, and helium is chemically inert. The hot helium can directly power a gas turbine or be used to generate steam for a water cycle.1

Nuclear reactors operate on the principle of nuclear fission, where heavy atomic nuclei split, releasing neutrons and energy. These neutrons can initiate further fissions, creating a self-sustaining chain reaction. In a controlled nuclear reactor, this chain reaction is maintained at a constant level, unlike the rapid, explosive reaction in an atomic bomb. The energy released from fission is the basis for nuclear power systems.23