Uncertainty quantification in the health consequences of the boiling liquid expanding vapour explosion phenomenon

摘要

A methodology for estimating the risk owing to the phenomenon of boiling liquid expanding vapour explosion (BLEVE) in the presence of uncertainties both in the model and in the parameters of the models is presented. BLEVE takes place when a tank containing liquefied petroleum gas (LPG) is exposed to fire and fails catastrophically. Two models have been used in the estimation of the intensity of thermal radiation from the resulting fireball, namely the solid-flame model assuming an emission power independent of the combustion mass and the point-source model that estimates the emissive power as a function of the combustion mass. Three measures of the BLEVE consequences, the intensity of thermal radiation, the dose of thermal radiation and the probability of loss of life as a result of the exposure to the thermal radiation and as a function of the distance from the center of the tank have been considered. Uncertainties in the exact values of the parameters of the models have been quantified and the resulting uncertainties in the three consequence measures have been assessed. A sensitivity analysis on the relative contribution of the uncertainty in each of the input variables to the uncertainties of the consequence measures has been performed. One conclusion is that the uncertainties in the probability of loss of life are mainly due to the uncertainties in the model of the physical phenomenon rather than to the uncertainties of the dose-response model.