Fuzzy modelling of HEART methodology: application in safety analyses of accidental exposure in irradiation plants

This study refers to the results obtained by Fuzzy Fault Tree analyses of accidental scenarios that entail the potential exposure of operators working in irradiation industrial plants. For these analyses, the HEART methodology, a first generation of the Human Reliability Analysis method, has been employed to evaluate the probability of human erroneous actions. This technique has been modified on the basis of a fuzzy set concept to more directly take into account the uncertainties of the so-called error-promoting factors, on which the method is grounded. The results also allow us to provide some recommendations on procedures and safety equipment to reduce the risk of radiological exposure.