b'3.1 FUELS DEVELOPMENTDemonstrate Machining Capabilities for Pu Bearing FuelsPrincipal Investigators: Leah Squires and Randy Fielding, INLTeam Members/ Collaborators: James Newman, Ryan Johnson, Steven Monk and Blair Grover (INL)This projectO ne key aspect to makea deformation process, or machined disposal and storage of usedafter casting. Machining, although demonstrates the abilitymetallic nuclear fuel easiernot optimal for full scale operations, to create numerousis elimination of the sodium whichis a useful tool for fabricating novel fuel geometries foris typically used to create a thermalgeometries which would require a irradiation testing viapath out of the fuel and allow for fuelsubstantial amount of process and machining as cast fuel. swelling.Due to its reactive nature,equipment development. Due to sodium in used fuel contributes athe high temperature phase change unique set of challenges when itof plutonium, machining of the comes to disposal.Since the mainmaterial presents a challenge. The high purposes of the sodium are thermaltemperature phase of the material is transfer and to allow the fuel to swell,brittle and difficult to machine and alternate methods by which to doheat from the machining process is these things are being explored.Onethought to bring about the phase such method is to allow for spacechange. The goal of this research was internal to the fuel pin for the swellingto find ways to machine Pu bearing to occur.In order to do this, holesmaterial that will allow for irradiation or spaces in the fuel may be createdtesting of novel fuel geometries within either during the casting processthe constraints of current gloveboxes or afterwards.This study lookedand facilities. Some geometries require at methods to machine plutoniumdrilling while others require turning bearing alloys in preparation foron a lathe. Previous work on U-Zr feasibility testing of metallic fuel formsfuels has shown it is also necessary suitable for irradiation without theto provide a smooth outer surface sodium bond. on the fuel for consistent thermal Project Description:conductivity in mechanically bonded In order to eliminate the sodiumfuels. The key objective of this project in used fuel, this work investigatedwas to demonstrate these capabilities alternative methods for creating ausing as cast plutonium bearing alloys. thermal path and allowing fuel toAccomplishments: swell. In particular, changes in the fuelThe main goal of this work was geometry to accommodate swellingto demonstrate the feasibility of while allowing a mechanical thermalmachining plutonium bearing fuels.bond show promise for achieving thisDue to the brittle nature of plutonium goal. Changing the fuel geometry willfuel alloys they can be challenging to require that the fuel is either cast inmachine. This is further complicated the novel geometry, forged throughby constraints of current facility 166 2019|AFC ACCOMPLISHMENTS'