Experimental and analytical studies of free convection film boiling around small spheres are reported. The relation of film boiling to possible vapor explosions is discussed. The system simulates the interaction between fragmented fuel particles and coolant in a nuclear reactor accident. Experiments were conducted on hot small brass spheres, 0.3175, 0.4762, and 0.6350 cm in diameter, suddenly immersed in Freon-11 and Freon-113, 0 to 20 K subcooled, at atomospheric pressure. Sphere temperature versus time cooling curves were obtained and minimum film boiling temperatures were determined. A lumped parameter system was used to convert the former-to-average heat flux versus wall superheat boiling curves. The experimental results for the saturated liquid film boiling agreed well with previous theoretical work of Hendricks and Baumeister. For subcooled liquid film boiling, the experimental results were compared to a theoretical prediction using an integral approach. Numerical solutions indicate that it is the ratio, not the difference, between the subcooled and saturated liquid film boiling Nusselt numbers that is significant. Minimum film boiling temperatures were found to increase with liquid subcooling at a rate slightly higher than linear. The effect of sphere size was that increased surface curvature shifts the minimum film boiling point toward higher wall superheats and higher heat fluxes. In the case of fuel fragmentation, these studies can be used to predict the resulting fuel-coolant interactions. A large increase in the minimum film boiling temperature is postulated. Thus film boiling would be terminated earlier and the coolant will be in direct contact with the surface at temperatures higher than its homogeneous nucleation temperature, resulting in rapid vaporization that may cause vapor explosions.