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

areas of safety R&d that are common to all envisioned magnetic fusion energy designs, including
tritium retention in irradiated materials, dust generation and entrainment, activation product
mobilization, and dispersal of chemically toxic materials. close correlation to other fusion development
themes exist because of the materials characteristics and configurations required for
solving the gaps in those themes. The limiting amounts for accidental release of these materials
are determined by the adopted safety approach, such as implementation of the no-evacuation criteria.
The effectiveness of release mitigation strategies can only be developed, evaluated, and refined
through safety integration in design.
MatERiaLS LiFE CyCLE ManagEMEnt
materials life-cycle management and environmental needs are broad and certainly influenced by
design configurations, materials selection, and operational performance. Proper handling of the
activated materials is important to the future of fusion energy. Fusion offers salient safety advantages
relative to other sources of energy, but generates a sizable amount of mildly radioactive
materials that tend to rapidly fill the Us low-level waste repositories. all three operational commercial
repositories will be closed by ~2050 before building the first Us fusion power plant. For
these reasons and to guarantee the environmental potential of fusion, geological disposal should
be avoided. Focus should be placed on more attractive scenarios, such as recycling and reuse of
activated materials within the nuclear industry and clearance or free-release to the commercial
market if materials contain traces of radioactivity.
There is a need for a global understanding of the activation levels throughout the fusion power
core to develop an integrated management approach for all activated materials. such an approach
should consider the radioactivity levels, remote handling issues, property of recycled materials
and cost. The key technological needs include the development of 3-d activation codes, remote
handling and treatment of tritium-containing materials, separation of materials from complex
components, detritiation and tritium capturing and handling, and refabrication of recyclable and
clearable materials.
This integral approach calls for major rethinking, education, and research to make the recycling
and clearance approaches a reality. in the 2000s, these new approaches have become more technically
feasible with the development of advanced radiation-resistant remote handling tools that
can recycle highly irradiated materials and with the introduction of the clearance category for
slightly radioactive materials by national and international agencies. note that such approaches
are straightforward in application from a technical standpoint, however, a substantial challenge
lies in influencing the policy, regulatory, and public acceptance aspects.
The Us fusion development program should consider implementing this state-of-the-art recycling
and clearance strategy to handle the expected large quantities of fusion-activated materials.
a dedicated R&d program would address the issues identified for strategic options. several areas
of scientific advancement underlie sound decisions in restructuring the framework of handling
fusion radioactive materials. examples of specific research needs include development of:
• low-activation materials that optimize alloying elements specifications to maximize
recycling after a short cooling period.
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