Research Needs for Magnetic Fusion Energy Sciences - US Burning ...

• neutron and other radiation transport, deposition and secondary nuclear reactions.
• effect of material changes and realistic fabrication processes on the component behavior
and design.
• techniques for measurement of phenomena and compatible instrumentation.
• synergistic phenomena driven by the unique combination of operating conditions.
• The key life-limiting and failure mechanisms, and how to identify and extend them.
• The interactions among plasma operation, tritium fuel cycle, material, safety and
secondary electrical generating systems.
Power extraction issues differ substantially from other energy sources, including fission, due to
the extreme conditions, multiple competing requirements, and the unique multi-physics environment
in which fusion power extraction components and materials must function. “traditional”
approaches and materials for high heat flux and nuclear heat removal are usually not applicable
in fusion because of these unique environmental factors and requirements, eliminating, for instance,
the use of many materials due to irradiation damage and activation concerns. specialized
combinations of materials including high-temperature coolants, tritium breeders, neutron resistant
structures, neutron multipliers or reflectors, electrical and thermal insulators, etc., are necessary,
leading to complex components with many interfaces. Unique phenomena such as magnetohydrodynamic
interactions of liquid metal coolants with the magnetic field, or radiation assisted
corrosion and tritium permeation, have a strong impact on the ultimate performance of
the power extraction components. The scientific understanding required to advance fusion nuclear
technology to a point sufficient to assure the feasibility and competitiveness of fusion energy,
or perform a practical and licensable design for a demo, must involve a significant database obtained
in relevant conditions.
gaps and Research Requirements
While significant progress has been made in understanding power extraction phenomena, new issues
and even more complicated behavior have been uncovered requiring further study and more
in-depth characterization. knowledge in many areas and scientific disciplines is still required. The
current view of these knowledge gaps are summarized below:
• a sufficiently complete understanding of component spatial and temporal temperature
variations, thermomechanical effects, coolant flow, and transport phenomena at fusion
relevant parameters.
• The impact of and techniques for control of coolant chemistry and impurities for fusion-
relevant coolants and conditions.
• knowledge about the occurrence, severity and consequences of synergistic phenomena
resulting from multi-field, multi-material, or multi-function effects.
• sufficient techniques to fabricate, maintain, and diagnose experiments, modules, and
components with fusion-relevant materials at fusion-relevant conditions.
150