ABSTRACT
The high-temperature gas-cooled reactors concept evolved from early air-cooled and CO2-cooled reactors. The use of helium in lieu of air or CO2 as the coolant, in combination with a graphite moderator, offered enhanced neutronic and thermal efficiencies. The thermal discharge from the gas-turbine modular helium reactor (GT-MHR) is significantly less than the PWR plant because of its greater thermal efficiency. The GT-MHR produces less heavy metal radioactive waste per unit energy produced because of the plant’s high thermal efficiency and high fuel burnup. Thermochemical water splitting is the conversion of water into hydrogen and oxygen by a series of thermally driven chemical reactions that could use nuclear energy as the heat source. The sulfur iodine thermochemical water-splitting cycle has been determined to be best suited for coupling to a nuclear reactor. A significant hydrogen economy is predicted to limit dependence on petroleum and reduce pollution and greenhouse gas emissions.
