b'team proceeded into this year with the goals of performing preliminary and final design analyses, technical design, and mockup fabrication of the FAST concept. The thermal analysis was performed (G. Beausoleil, INL) using finite element software to investigate the fuel designs of interest, the impact of fabrication tolerances, the consequence of eccentricities and component offsets, and fill gas varia-tions (He/Ar mixtures). The thermal analysis provided important insight into the thermal gradients within the fuel specimens, which can significantly affect fuel performance phenomena.Mechanical analysis was also performed (K. Gagnon, INL) using finite element analysis software. While the capsules being used in FAST have been previously analyzed for their use Figure 2. Top image shows an asto high burnup targets in ATF-1 and AFC experiments, there cast mock-up pin of the fuel. FuelThis project will provide INL anwas a slight adjustment incorporated pins will be cast to this dimensionaccelerated irradiation platform thatinto the design so that pressurized gas and then machined to the desiredcan be used in a high-heat flux gap dimension/geometry. can be easily adopted to multiplebetween capsules. This modification fuel forms and reactor designs. Therequired mechanical analysis in order benefits will enable the laboratory andto ensure that the capsules still met Department of Energy (DOE) to meetthe requirements of the ATR Safety industry needs for quickly investi- Analysis Report.gating advanced fuel concepts and achieving the objectives of deployingNeutronic analysis was performed (B. safe, reliable, and economic operationCurnutt, INL) using MCNP-ORIGEN of next generation reactors. software on generic experiment Accomplishments:concepts to determine power profiles Previous work (INL/EXT-18-45933)for the fuel and non-fissile heat provided scoping analyses of the FASTgeneration rates for components concept. Those results demonstratedwithin the capsule. These values were the feasibility of reducing the sizeused to provide enrichments to the of the fuel pin and cladding whilefuel fabrication team and to verify maintaining near-prototypic condi- that the heat loads of the capsule are tions. From the scoping analysis thewithin the safety limits of the original capsule designs.198 2019|AFC ACCOMPLISHMENTS'