Comparison of Options for a Pilot Plant Fusion Nuclear Mission

Issues and strategies for DEMO in-vessel component integration

“…Previous international DEMO/fusion power plant studies, [7][8][9], considered a semi-permanent in-vessel shield: a shell structure within the vessel providing support to the IVCs and neutron shielding to the vessel and superconducting coils, actively cooled to a temperature similar to that of the IVCs, see Fig. 1.…”

Initial DEMO tokamak design configuration studies

“…Previous worldwide fusion DEMO/power plant studies [10,13,14], considered a semi-permanent in-vessel shield: a toroidally continuous shell structure actively cooled to a temperature similar to that of the IVCs, providing support to the IVCs and neutron shielding to the superconducting coils. Instead in the current DEMO configuration both blanket and divertor are directly supported by the vessel, which also takes over the neutron shielding function of the shield.…”

Mission and Readiness Assessment for Fusion Nuclear Facilities

“…Here we consider two FNF mission options, an advanced tokamak fusion nuclear science facility (FNSF-AT) similar in design and scope to the FDF 7 proposed by General Atomics and collaborators, and a pilot plant 9,13 based on studies by PPPL and collaborators. Mission parameters for these two options are tabulated along with those for ITER and DEMO in TABLE II.…”

“…This approach is potentially advantageous for achieving good alignment of components such as the divertor targets, since the assembly into ring structures is performed ex situ, and may simplify the support structure design. However as pointed out by Brown, 13 the jointed TF design may be less reliable in steady-state operation and the disassembly of major subsystems to gain access can add risk in damaging the disassembled components. The complexity and long maintenance turn-around times of today's much simpler machines, such as NSTX and JET, suggests that costs and risks of extensive disassembly of a steady-state nuclear machine like FNSF-AT to gain access may impact its productivity and negate any capabilities it might offer in terms of re-configurability.…”