Historical Fission Plant Availability and the Operation Goal for a Fusion DEMO

As fusion researchers look toward the future, there have been discussions on what the plant operation goals should be for a demonstration fusion power plant (DEMO). The U.S. Research Needs Workshop (ReNeW) in 2009 stated that power producers (the companies owning power plants) could not expect an ultimate fusion power plant availability of 80% or more if a DEMO reactor cannot demonstrate a 50% or higher availability. The ReNeW panel also stated that achieving 50% availability with a DEMO plant would be a huge accomplishment. Other recent DEMO design studies have given goals for plant availability as well. This technical note presents historical plant availability values of new technology fission power plants to compare fission achievements with the suggested goals for fusion DEMO plant designs. Demonstration fission plants that met or exceeded 40% average annual availability were generally considered to be successful. These data help to support the goal values that have been put forward in various studies.