An Advanced Gas-Cooled Reactor (AGR) is a type of nuclear reactor that uses carbon dioxide as a coolant and graphite as a moderator. It is designed to generate electricity by harnessing the heat produced from nuclear fission. AGRs are known for their high thermal efficiency and ability to operate at higher temperatures compared to other reactor types. The AGR technology was developed in the United Kingdom and is primarily used in British nuclear power plants. These reactors are notable for their safety features and low emissions, making them a significant part of the country's energy strategy, alongside other sources like renewable energy and fossil fuels.