b'of bulk and atomistic understandingThe SEM, taking place at the Center DISECT is a venueof the phase transformation kineticsfor Advanced Energy Studies (CAES) for separate effectstaking place during expectedand INLs Fuels and Applied Science testing on U-Zr alloysoperating conditions. Coupling theseBuilding (FASB), was performed intended to advancewith postirradiation examination (PIE)on U-10wt.%Zr and U-30wt%Zr the fundamentalwill allow for the study of irradiationssamples throughout the novel understanding ofinfluence on phase transformationsfabrication process, pictured inthe microstructuraland microstructure. UnderstandingFigures 1 & 2, respectively. This evolution, both in andthe precise nature of microstructuralwork illustrates microstructural out of pile, in order toevolution taking place underrecovery of the U-10wt.%Zr alloy aid in the transition fromirradiation will allow for the tailoringafter rolling and annealing to that empirical to mechanisticof reactor conditions or fuel designexpected following typical heat modeling required toneeded to extend the fuel lifetime.treatments. Additionally, the SEM advance metallic fuelsAdditionally, being able to performanalysis was used to characterize the to moderate and highmore accurate predictive modelingmicrostructure of both the 10 and burnups. will allow for a more precise30wt% alloys under two unique heat identification of safety margins.treatments, describing the thermal Accomplishments:historys influence on microstructure. Preliminary thermal and neutronicsPurdue University was awarded two analysis were completed on the testRapid Turnaround Experiments, RTEs, vehicle at INL and SCKCEN, respec- namely In-Situ Phase Analysis of tively. These analyses indicate that thePhase Transitions in U-(6, 10, 20, fuel and vehicle design are capable30) wt%Zr Fresh Fuels using Neutron of irradiating samples under targetedDiffraction and Phase Evolution of fast reactor conditions while decon- Uranium-Zirconium Alloys under voluting thermal, compositional, andIn-Situ TEM Heating.neutronic effects. These analyses wereThe neutron diffraction work, critical to the completion of phasescompleted at Los Alamos Neutron 1/3 and 2/3 of the CEE (CommitteeScience Centers (LANSCE) Lujan for the Examination of Experiments),Neutron Scattering Center pictured in a safety review for reactor insertion,Figure 3, made precise measurements with the third scheduled to take placeon crystal structure, phase fractions, in early fiscal year (FY) 20. Followingand texture throughout fabrica-the completion of safety reviews,tion. Further examination was also fabrication continued, and preirradia- performed with in-situ heating and tion characterization began.controlled cooling with the intent of furthering the understanding 210 2019|AFC ACCOMPLISHMENTS'