Application of high-frame-rate neutron radiography to steam explosion research

To understand the behavior of dispersed molten metal particles dropped into water during the premixing process of steam explosion. experiments were pe rformed by using heated stainless-steel particles simulating dispersed molt en metal particles. High-frame-rate neutron radiography was successfully em ployed for visualization and void fraction measurement. Visualization was c onducted by dropping heated stainless-steel particle into heavy water fille d in a rectangular tank with the particle diameter (6, 9, and 12 mm) and te mperature (600 degrees C, 700 degrees C, 800 degrees C, and 1000 degrees C) as parameters. Steam generation due to direct contact of heated particle a nd heavy water was successfully visualized by the high-frame-rate neutron r adiography at the recording speed of 500 frames/s. From void fraction measu rement it was revealed that the amount of generated steam was in proportion to the particle size and temperature. It is suggested that the ambient liq uid might be superheated by the particle-liquid contact. (C) 1999 Elsevier Science B.V. All rights reserved.