Spread and evaporation of liquid

The first stage in the development of many accident sequences which lead to a major hazard (e.g. from fire, explosion and toxic effects) is the release of hazardous material from its containment and the consequent generation of hazardous vapour. High potential hazards are clearly presented by large quantities of hazardous material which are usually stored and transported in the liquid phase, either refrigerated at low overpressure or pressurized at ambient temperature (n.b. some hazardous materials are also contained under semi-refrigerated conditions). The purpose of this paper is to discuss the characteristics of hazardous material release and hazardous vapour generation for both refrigerated and pressurized liquid containment situations. Refrigerated and pressurized containment will be considered separately, since the characteristics of both release and vapour generation are qualitatively different for the two containment situations. Greater attention will be given to refrigerated liquid containment, since the maximum quantity of hazardous material stored in this form may be an order of magnitude greater than that stored in pressurized liquid containment.