A pilot plant as the next step toward an MFE Demo

An assessment of Demo goals and of prerequisites for Demo readiness motivate an examination of a pilot plant: an intermediate facility designed to substantially narrow the technical gap to Demo in a next step. A pilot plant would: 1) test internal components and tritium breeding in a steady-state fusion environment, 2) prototype a maintainable design and maintenance scheme for a power plant, and 3) generate net electricity. Preconceptual designs based on the advanced tokamak (AT), spherical tokamak (ST), and compact stellarator (CS) have been developed in order to compare their relative merits as fusion systems. Any of them would take a large step toward Demo in key performance metrics, e.g. engineering gain QENG (≥1), neutron wall load (>1MW/m2), tritium breeding ratio (>1), pulse length (10⁶-10⁷ s), blanket lifetime fluence (≥3MW-yr/m²), plant lifetime (6-20MW-yr/m²), and availability (10-30%), but they differ in their associated risks.