b'First Irradiated-Fuel Fast Reactor Experiments in TREAT:Assembly and PerformancePrincipal Investigator: Klint AndersonTeam Members/Collaborators: Jason Schulthess, Trevor Smuin, Robert Armstrong, Jordan Argyle, Clayton Turner, Philip Petersen, Justin Yarrington, Randall Fielding, Sarah Khan, Todd Birch, Ashley Lambson, Colby JensenT he Advanced Reactorheating. THOR features an advanced Experiments for Sodium Fastinstrumentation package which is Reactor Fuels (ARES) projectcustomizable for measuring different is a collaboration between the U.S.phenomena of interest depending on Idaho National Laboratory (INL) andthe individual experiment objectives. the Japanese Atomic Energy AgencyThe capsule is heavily instrumented, (JAEA) to investigate the transientespecially for temperature, and fuel performance of irradiatedincludes numerous thermocouples advanced metallic and mixed oxidemonitoring the specimen tempera-(MOX) fuel designs. As part of theture at various axial elevations. ARES project, a new sodium capsuleAdditional instrumentation included for use in the Transient Reactor Testin THOR is a linear variable differ-Facility (TREAT) has been developedential transformer to measure either to test fresh and pre-irradiated fuelpressure or fuel elongation and an designs from the Experimentalacoustic emission sensor for cladding Breeder Reactor (EBR)-II experimentrupture detection. Figure 1 shows an programs. Testing completed in thisoverview of the THOR capsule.new sodium capsule has providedThe THOR capsule was designed fuel performance data of Sodiumto facilitate remote handling and Fast Reactor (SFR) fuels to supportloading inside the Hot Fuel Examina-continued improvement in fueltion Facility (HFEF) to provide fuel performance and economics. performance data on pre-irradiated Project Description:metallic and MOX fuel pins. Three The Temperature Heat Sink Over- fresh fuel commissioning tests were power Response (THOR) capsule isperformed leading up to fiscal year a static sodium capsule designed for2023. These commissioning tests, irradiation in TREAT. The capsule isalong with the design, demonstra-sized to house a single EBR-II styletion, and deployment of remote fuel pin which is sodium bonded tohandling equipment in HFEF, paved an internal heat sink. The capsulethe way for the first TREAT fast includes a cable heater which isreactor experiments with pre-irradi-wrapped around the heat sink andated fuel and second overall preir-provides pre-transient specimenradiated fuel test since TREAT restart.176 2023|AFC ACCOMPLISHMENTS'