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

each Thrust 13 element includes the related theory and modeling to help understand, apply and
generalize the experimental results. These modeling efforts and codes are then available to Thrust
15, which integrates modeling results from a variety of areas, especially Thrust 14 on parallel material
development, characterization and engineering.
This progression is similar to the concept of technical Readiness levels or tRls used successfully
in other fields to gauge and guide the progression of understanding and service readiness of complex
technologies. This Thrust encompasses in its scope many different components needed for
fusion power extraction and the tritium fuel cycle, and each of these components will have different
concepts, materials, coolants, etc. so a broad program of research with concepts at different
stages of readiness and development is foreseen. however, unification and direction within this
Thrust will come from close coupling with Thrusts 14 and 15, Thrusts 11-12 concerning plasma
facing components (PFcs) such as the divertor, and plasma-related thrusts emphasizing control,
off-normal events and configuration.
Fundamental Research — Perform fundamental research to establish the scientific parameters
necessary to address power extraction and tritium fuel cycle issues.
advancing Fnst knowledge at the fundamental scientific level is needed in many areas to complete
the separate-effects database and establish the basic phenomenological and constitutive
models necessary to understand tritium control, processing, and power extraction components
for fusion. it is not possible to present a complete list, but example areas include:
• lead-lithium alloy tritium chemistry, heat and mass transport characteristics, isotope
and impurity control, etc.
• liquid metal magnetohydrodynamic (mhd) interactions for liquid metal blankets, firstwall
melt layers and free surface divertors.
• tritium processing and containment (diffusivity, solubility, reaction rates, activity
coefficients, etc.) for a variety of candidate materials and temperatures.
• ceramic-breeder pebble-bed response to thermomechanical load and cycling.
• interaction database of beryllium and liquid metal alloys with water and air.
significant past work has been done in many of these areas, and progress has enabled the refinement
and improvement of the conceptual design of components for fusion. however, gaps remain
and an intensive program of laboratory-scale experiments and model development that address
these gaps is envisioned. emphasis should be placed on leading and alternative power extraction
and fuel cycle systems, and on both safety and reliability aspects. The scope of effort in this first
stage is roughly a handful of focused university and laboratory programs, and is not large compared
to the current plasma physics program in the Us. enhancement in this area of research is
essential.
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