Overview and Status of the Advanced High-Temperature Reactor

Abstract – A new reactor concept, designated the Advanced High-Temperature Reactor (AHTR), is being developed that uses liquid fluoride salt as a coolant, graphite moderator and high-temperature coated-particle fuel. The concept is being supported by the U.S. Department of Energy as part of the Generation IV program as a “coolant variant ” of the Very High-Temperature Reactor because it shares many of the same fuel, moderator and material technologies. The purpose of the AHTR is to provide an advanced design that is sufficiently robust to allow a growth path to higher power output and higher temperatures, and also offering the potential for highly competitive economics. Although it creates some unique technology challenges of its own, the AHTR has many strong advantages, such as: lower reactor fuel temperatures, low-pressure reactor vessel and piping, enhanced safety features, and improved economics. Several analyses have been performed during the past two years to demonstrate the physics viability of the concept and to support the development of a preconceptual design. The evolution of the concept is presented, along with a description of the present design and a summary of key performance analyses