b'Conception of an EnhancedThree-dimensional nuclear transport modeling decreases the cost of sodium-Fast Neutron Test Capability incooled fast reactor fuel development by showing a pathway to simulate reactor a Thermal Spectrum Reactor conditions using existing fuel assemblies and the Advanced Test Reactor.D evelopment of advanced fuels and materials for fast spectrum nuclear reactors is an immense challenge with tremendous potential to maximize the value of advanced nuclear plants. Historical developments and modern materials show promise for overcoming these challenges, but the current lack of fast neutron test capabilities in the western world hampers meaningful progress. TOTAL APPROVED AMOUNT:This project used modern modeling to investigate a new method for fast neutron $120,000 over 1 year irradiations in an existing thermal-spectrum reactor, the Advanced Test Reactor. This new method will build upon past ideas where fast flux is increased by surrounding PROJECT NUMBER:the specimens with fissionable booster fuel, but diverges from historical approaches 20A1049-002 by using an off-the-shelf fuel assembly as the booster fuel while leveraging PRINCIPAL INVESTIGATOR:advancements in three-dimensional simulation and geometries enabled by modern Nicolas Woolstenhulme manufacturing. This concept has been termed the Advanced fast Reactor Concept in Thermal-spectrum Irradiation Capability (ARCTIC). These studies used modern CO-INVESTIGATORS: modeling to investigate the hypothesis that ARCTIC would result in a worthwhile Bryon Curnutt, INL fast flux increase whose deployment in the Advanced Test Reactor would be timely Colby Jensen, INL in maturing fast spectrum research while the community awaits availability of a true Kevan Weaver, INL fast spectrum test reactor.TALENT PIPELINE:Keegan Pombier, student at University of MichiganPUBLICATION:Curnutt, B., N. Woolstenhulme, J. Nielsen, N. Oldham, K. Weaver, C. Jensen, and A. Fradeneck, A neutronics investigation simulating fast reactor environments in the thermal spectrum advanced test reactor, Nuclear Engineering and Design, 387 (2022) 111623.Normalized flux energy profile within ARCTIC with no thermal neutron filter, cadmium filter, and europium(III) oxide filter.40'