The Trigger Mechanism of Vapor Explosion

Abstract

In the present study, trigger mechanisms of the vapor explosion are experimentally investigated. The interfacial behavior between high temperature molten liquid and low temperature water are experimentally investigated by using a molten material droplet and external pressure pulse. As the results, it is indicated that spontaneous vapor explosion hardly occur in high temperature water near saturation temperature since vapor film is stable. The vapor explosion can occur even in high temperature water near saturation temperature in case that the external pressure pulse is applied to high temperature molten material. Vapor explosion can not occur when the interfacial temperature between the molten material and water is lower than the material melting temperature, even if the vapor film around the molten material is collapsed by the external pressure pulse. It is clarified that the impossibility of the trigger process for the vapor explosion can be judged by comparing the interfacial temperature and the molten material temperature. The results obtained in the present experiments are applied to the results of the large-scale experiments using uranium dioxide. The results indicate that the possibility of the vapor explosion of the uranium dioxide and water under the present LWR operational condition is extremely unlikely. It should be noted that the present criteria should be applicable in case that the melting temperature does not decrease by containing the metal component.

Vapor explosion in steel mill industries: Chemical composition analysis on molten slag and coolant

“…However, research on the vapor explosions has been conducted mainly on nuclear power plants. Procedure of the vapor explosion is addressed as four steps [1][2][3][4][5][6][7][8][9] like below.…”

Risk Factors of Vapor Explosion of Molten Slag in Slag Yard for Steelworks

“…This revealed only a substantial part of the reoccurring vapor explosions caused by molten slag. Vapor explosions are a physical phenomenon in which explosive boiling occurs when heat contained in molten slag is rapidly converted to gas, and although steel mills make efforts to prevent such a phenomenon, one or more vapor explosion accidents cause fatalities and property damage every year [1][2][3].…”