With the construction of ITER underway, there has been renewed strong interest worldwide in defining in detail the roadmap to realizing fusion power. Since plasma burn physics and plasma support technologies are addressed by ITER, there is now a much greater recognition worldwide that Fusion Nuclear Science and Technology (FNST) is the remaining principal challenge. Therefore, the central element of the current planning activities is focused on the question: what are the research and major facilities required to develop FNST to the level necessary to construct and successfully operate a fusion DEMO? FNST is the science, engineering, technology and materials for the fusion nuclear components that generate, control and utilize neutrons, energetic particles and tritium. The principal challenges in the development of FNST are: 1- The Fusion Nuclear Environment - it is a multiple-field environment (neutrons, heat/particle fluxes, magnetic field, etc) with high magnitude and steep gradients; 2- Nuclear Heating in large volume with sharp gradients - the nuclear heating drives most FNST phenomena but adequate simulation of this nuclear heating can be done only in DT-plasma based facility; and 3- Complex Configuration with Blanket/First Wall/Divertor inside the vacuum vessel - the consequence is low fault tolerance and long repair/replacement time.
These FNST development challenges result in critical consequences: A- Non-fusion facilities (laboratory experiments) need to be substantial to simulate multiple fields, multiple effects, B- Results from non-fusion facilities will be limited and will not fully resolve key technical issues. A DT-plasma based facility is required to perform multiple effects and integrated fusion nuclear science experiments, C- Reliability/Availability/Maintainability/Inspectability (RAMI) of fusion nuclear components is a major challenge and is one of the primary reasons why FNST will pace fusion development toward a DEMO.
Launching an aggressive FNST R&D program now is essential to defining a credible path to realization of fusion power. This talk will highlight the FNST strategic issues, challenges, and facilities on the pathway to fusion DEMO.