5.68. Probabilistic assessments can be used to quantify the risks associated with the scenarios in a manner that takes account of a range of parameter values arising from associated uncertainties. Probabilistic assessments should avoid realizations with combinations of the parameters corresponding to states of the system that would be impossible or very unlikely in practice. Impossible combinations of parameters may be generated, in Monte Carlo simulations, when sampling from the probability distributions of the different variables, for example, if correlations are not taken into account. Probabilistic assessments should also be conducted so as to avoid undue ‘risk dilution’, i.e. masking of the impact of a very significant event at some point in the lifetime of the facility by rendering its consequences of little significance in the overall assessment of risk when multiplied by the probability of occurrence of the event [38].