b'Figure 3. EPMA points analyses ofevents, and support determinationunderwent final preparations in IMCL the main elements redistributionof a possible source term. Samplesfor measurements by the EPMA. (U, Pu, Zr) across the 2 main axesof the foam structure region at theThe polishing procedure used a (radial A-B and axial C-D) as showntop of the fuel pin were prepared andnonaqueous solution in an attempt to in the back-scattered electron (BSE) image on the left. have been analyzed using EPMA toretain water-soluble fission products. reveal a detailed compositional andSamples were then analyzed by microstructural understanding of EPMA in IMCL using the shielded this region.Cameca SX100 R (Figure 1), capable Accomplishments:of handling irradiated fuel. Both The metallic fuel specimen with metalquantitative point analyses and WDX foam was retrieved from the Hotmaps were acquired to investigate the Fuels Examination Facility (HFEF)microstructural evolution of the foam at INL. A section from the top of thestructure, fission product behavior, fuel rod was chosen to assess theand redistribution of primary base-foam microstructure and integrityalloy compositional elements. after a moderate transient. OpticalThe analysis results revealed three microscopy was conducted on thetypical alloy redistribution regions specimen in HFEF for preliminary(Figures 2-3): 1) the central region examination supporting followingwith slightly enriched in Zr-Pu; 2) the steps. Subsequently, the sampleannular neighboring area showing Zr 222 2019|AFC ACCOMPLISHMENTS'