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

3. buildup of tritium and impurity concentrations, and distribution to equilibrated levels.
4. impact on component behavior by radiation damage of in-service materials.
Perhaps this can be done in a single staged facility or perhaps more than one facility will be required.
The scale of effort will be large, and the planning and design of such a nuclear facility is
itself an intensive task. The mission, capabilities, and time scales for such facilities must be carefully
considered in a demo readiness program.
Connection to Safety and Reliability — Develop theory and predictive models, and collect reliability
and safety data at all stages.
incorporation of activities in Thrust 13 will be instrumental in the design of an FnsF and subsequent
demo, which in turn will need to meet demanding safety and Reliability, availability,
maintainability, and inspectability (Rami) requirements described in the harnessing Fusion
Power Theme chapter. While the research activities in Thrust 13 stem from establishing the feasibility
of fusion power extraction and the tritium fuel cycle, they will naturally result in opportunities
to collect and document information on Rami and safety. as components begin to fail during
testing, the conditions and mode of failure will be identified, understood, and documented.
improved test conditions and components can then be designed and introduced for further testing
to build a critical Rami database. For safety, fundamental constitutive behavior and reaction
rates from complex systems behavior and failure modes will form the database for safety source
terms and modeling. experiments needed to challenge hazards mitigation will be identified and
performed as part of the testing program.
Connections to Other Thrusts and Themes in Plasma Science and Engineering
in addition to the close linkage to Thrusts 14 and 15 (already discussed), research on fusion power
extraction and the tritium fuel cycle must be closely linked to other thrusts, notably those focused
on PFcs, PWi, internal components, plasma configuration, and burning plasma.
The first wall, divertor power extraction and tritium control are intimately connected to PFc and
PWi issues. operation of plasma contact surfaces at high temperatures and with neutron damage
is likely to change their behavior vis-à-vis tritium retention, recycling, diffusion and impurity
generation. The potential use of liquid metal free surface divertors, or the occurrence of melt layers
during off-normal plasma events, also requires concurrent understanding of the mhd flow
dynamics and control, coupling between liquid surfaces and the plasma, as well as the impact on
edge behavior, particle pumping, tritium burn fraction and plasma impurity control. Thrust 13 attempts
to be inclusive of power extraction and tritium fuel cycle issues critical for the successful
operation of PFcs. however, Thrusts 11 and 12 also include a detailed strategy to address many
of these gaps in concert with plasma wall material development and interactions in special test
facilities. The research described in Thrusts 11 and 12 should be in concert with the test facilities
described as multiple effects testing in Thrust 13, with emphasis on coupled power extraction, tritium
and plasma material interaction issues.
The plasma magnetic configuration, operational modes, and the plasma control hardware (most
notably Thrusts 1, 5, 16, 17, 18) will have a strong impact on establishing tritium self-sufficiency
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