Gas-cooled reactors (GCRs) are a type of nuclear reactor that use gas, typically carbon dioxide, as a coolant. This design allows for high operating temperatures, which can improve the efficiency of electricity generation. GCRs often use graphite as a moderator to slow down neutrons, facilitating the fission process. One of the main advantages of GCRs is their ability to operate at higher temperatures compared to water-cooled reactors. This feature makes them suitable for various applications, including hydrogen production and process heat for industrial uses. GCRs are also known for their inherent safety features, reducing the risk of overheating.