PROPAGATION OF FUEL COOLANT INTERACTIONS IN MULTI-JET EXPERIMENTS WITH MOLTEN TIN

A study of the propagation of fuel-coolant interactions (FCI) has been carried out, using a so-called droplet curtain arrangement of molten tin in water. To create the two-dimensional arrangement of the droplet curtain, the melt was heated up in a rectangular crucible with an exchangeable steel plate in which holes were bored with the desired diameter at corresponding distances. By tilting the crucible, multi-jets of hot molten tin flow through the holes side by side into a container filled with water and the jets disintegrate into several smaller jets of droplets. An interaction was triggered in the water container at the first drop chain by a shock wave generated by an underwater bridge wire explosion. A propagation of interactions from edge to edge took place for instance with the following parameter combination: tin temperature 650-degrees-C. water temperature 70-degrees-C, hole diameter 5 mm and the distances between holes 25 mm. This parameter combination yielded an average propagation velocity in the horizontal direction of 2.7 m/s and in the vertical direction of 2.1 m/s.