ON MODEL UNCERTAINTY OF FIRE RISK OF GROUND TANK WITH GASOLINE

Currently, the risk management methodology can be considered only as a supplement to traditional deterministic methods of safety management. This is mainly due to the large uncertainty in the performance of quantitative risk assessment (QRA). Technological risks should be treated as a vector quantity, that two components have: a) the probability component of risk, and b) a component of risk associated with the damage. Any quantitative estimates made in the QRA, have an uncertainty, the value of which can be up to three orders of magnitude. The issue of quantifying uncertainty was put prof. N. Rasmussen in 1975, when the report WASH-1400 developed. Research problems quantify uncertainty in Russia lags far behind the work done in the New and Old World. Considering these uncertainties, traditionally distinguished:
at first, the aleatory and epistemic its diversity;
secondly, a model and parametric components. A special case of model uncertainty is the scenario uncertainty. All containers used for storage of petroleum products can be divided into two types — vertical and horizontal. Russian regulations and methods to quantitative assessment of fire risk do no differences between them, which creates a very large uncertainty. Of the full range of emergency scenarios on a tank of oil products is the most dangerous BLEVE and fireball. Statistics show that in the past were observed by type of rare crash fireball on tanks with gasoline that always accompany BLEVE. According to modern ideas, BLEVE is an explosive homogeneous boiling of superheated liquid. There is reason to believe that the type of BLEVE explosion can only with fire engulfed horizontal tanks because of their very strong mechanical bond than with vertical tanks. Thus, the scenario uncertainty in the case of QRA of ground tank with gasoline can be significant.