b'Figure 3. Selected results from MIT-led project: High-speed images at and after CHF for the bare Zr-4 material, Cr-coated Zr-4 with PVD coating, and Cr-coated Zr-4 with cold-spray coating. Both Cr-coated specimens show excellent resilience during the high-temperature CHF condition compared to bare which induces material failure at CHF.effects including surface wettability,HTC-NB in the weak forced convection capillary wicking, and the solid-liquidregimes due to the surface morpho-heat conduction, and 2) the heatlogical factors and the variation of convection effects resulting from massthermomechanical properties.flux and liquid subcooling. The effectProject 17-13019of cladding material on saturated pool boiling CHF is the most pronounced inTitle: Evaluation of Accident Tolerant pool boiling conditions, since convec- Fuels Surface Characteristics in Critical tion heat transfer plays a weak roleHeat Flux Performancein these conditions relative to otherInvestigators: S. Bilbao y Leon (currently boiling conditions. Both the onsetNEA); J. Rojas, Virginia Commonwealth of nucleate boiling (ONB) and heatUniversity; M. Anderson, University of transfer coefficient of nucleate boilingWisconsin-Madison; R. Rebak, General (HTC-NB) also show similar tendenciesElectric; R. Martin, BWX Technologies; of material dependence with respect toR. Harne, Framatomemass flux and inlet subcooling. It also indicates that the formation of oxideSelected Highlights: The objective of layer can influence CHF, ONB, andthis project is to perform separate-effects tests of several of the ATF 2020|AFC ACCOMPLISHMENTS 41'