“…After defining probability, it is a simple matter to make the risk matrix, combining consequences with probabilities. According to the description given in table 1, explosion of the pressure vessel, considered here, corresponds to the category 5, because of potentially catastrophic scenario, as defined in [3,4]. As one can see, points 1 and 4 have the highest risk, then comes point 2, whereas points 3 and 5 have moderate risk.…”