Fusion Nuclear Science Pathways Assessment
Authors: C.E. Kessel, et. al.
Abstract: With the strong commitment of the US to the success of the ITER burning plasma mission,
and the project overall, it is prudent to consider how to take the most advantage of this
investment. The production of energy from fusion has been a long sought goal, and the
subject of several programmatic investigations and time line proposals [1]. The nuclear
aspects of fusion research have largely been avoided experimentally for practical reasons,
resulting in a strong emphasis on plasma science. Meanwhile, ITER has brought into focus
how the interface between the plasma and engineering/technology, presents the most
challenging problems for design. In fact, this situation is becoming the rule and no longer
the exception. ITER will demonstrate the deposition of 0.5 GW of neutron heating to the
blanket, deliver a heat load of 10-20 MW/m2 or more on the divertor, inject 50-100 MW of
heating power to the plasma, all at the expected size scale of a power plant. However, in
spite of this, and a number of other technologies relevant power plant, ITER will provide a
low neutron exposure compared to the levels expected to a fusion power plant, and will
purchase its tritium entirely from world reserves accumulated from decades of CANDU
reactor operations. Such a decision for ITER is technically well founded, allowing the use of
conventional materials and water coolant, avoiding the thick tritium breeding blankets
required for tritium self-sufficiency, and allowing the concentration on burning plasma and
plasma-engineering interface issues. The neutron fluence experienced in ITER over its
entire lifetime will be ~ 0.3 MW-yr/m2, while a fusion power plant is expected to experience
120-180 MW-yr/m2 over its lifetime. ITER utilizes shielding blanket modules, with no
tritium breeding, except in test blanket modules (TBM) located in 3 ports on the midplane
[2], which will provide early tests of the fusion nuclear environment with very low tritium
production (a few g per year).
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Submitted to: PPPL Reports
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Download PPPL-4736 (pdf 17.52 MB 282 pp)
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