Shortcomings of Linear Risk

Equation 1,4-7 is unsatisfactory because the risk from a large number of small accidents is the same as from a small number of large accidents if the total number of effects, say fatalities, is the same for each case. It is hypothesized that the perceived risk of a large accident is greater than the equivalent risk from many small accidents because of human nature and the emphasis of the news services on the unusual (50,OCX) traffic deaths per year is not newsworthy, but a single accident killing 50,000 is very newsworthy). 

To address this nonlinearity, it has been proposed that the risk equation be modified as shown in equation 1 4 S where the consequences are raised to the u-power to account for the effects of perception. Unfortunately, a physical basis for the value of u has not been established, but a suggested value is 1.2 (NUREG-0739), If vwere set to 1, then risk would be linear and not allow for perception. 

Lt)iiibinations as dots, the accidents are presented as exceedance plots, i.e., the probability that a consequence X will be exceeded. 

As a final comment on inadequacies of mathematical representations of risk, those who bear the risk are not necessarily those who receive the benefit. While unequal distribution of risk and benefit may not be fair, it is difficult to redress die incquily. 

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