Analysis and account of human factor during Chernobyl accident at 26 april 1996 by modern methods

The a posterior analysis and account of human factor were carried out by means of probabilistic analysis on the basis of 'THERP' methods. The probability of collective operator's error has been calculated with account of all circumstances, external and internal factors: personnel work organization and work conditions; tools available to the personnel including operational documentation, accessible information including information about lacks and 'trouble spots' of the equipment. The inadmissible high probability of collective error has been shown, i.e. we have received the answer to the question: 'Why the erroneous actions were performed?'