ABSTRACT
The stainless steel surrounding the fuel rods allows a gas reactor to be operated at a higher temperature, but it sacrifices some neutron economy in the process. The high-temperature gas reactor (HTGR) is the American equivalent of the British advanced gas-cooled reactor (AGR). The AGR and the HTGR are the two most popular gas reactors in the world. Gas reactors, military reactors, and liquid metal fast breeder reactors (LMFBR) make up most of the rest of the power reactor installed base in the world. The chapter discusses each of the designs and their relevance to the field of nuclear power as a whole. A pool-type LMFBR has a different set of design tradeoffs that must be weighed against the fact that almost all of the critical components are immersed within a single pool of liquid sodium. Each of the fuel assemblies in an LMFBR is surrounded by a hexagonal sheath or “can.”
