Method for setting up the truncation limit of probabilistic safety assessment

Truncation defines cutting off the negligible contribution of the results of the probabilistic safety assessment. A method is developed, which defines truncation limit in probabilistic safety assessment. The new method specifies the truncation limits with more requirements. The results show that application of the new method largely reduces the large relative errors of importance measures in probabilistic safety assessment. Evaluation of examples shows that application of the method can reduce the relative errors for more than one order of magnitude. It is recommended that users of probabilistic safety assessment consider the method and its findings for setting up the truncation limits in order to have probabilistic safety assessment results, which can serve as a standpoint for decisions.