2017 | AFC ACCOMPLISHMENTS 158 AAn annular metallic fuel is one the advanced fuel concepts that are under development by the Advanced Fuel Campaign (AFC).The primary motivation of the annular fuel is to reduce fuel smeared density (< 75%) for accommodating swelling of ultra-high burnup fuel without major fuel-cladding mechanical integration.The annular fuel in contact with cladding could eliminate the need for sodium bond, which provides various impacts on reactor performance characteristics as depicted in Figure 1. Assessment of the Impacts of Annular Fuel on Reactor Performance Principal Investigator:T. K. Kim Collaborators: G. Aliberti, N. Stauff Project Description: The primary objective of this study is to assess the impacts of annular fuel on reactor performance characteristics. As long as fuel composition and fuel smeared density are retained, neutronics performance (i.e., flux level, burnup, power distributions, etc.) of the annular fuel are comparable with those with a solid fuel. However, absence of bond-sodium in the annular fuel allows relocation of fission gas plenum below active fuel rather than above, which is typical location in a solid fuel. Since the gas plenum is located at low temperature position, the annular fueled Sodium Fast Reactor (SFR) has different reactor performance The transmutation fuel package has supplied fuel samples for thermal and microstructural characterization as well as the fuel and assembly of the AFC-3F irradiation test.