Preliminary Analysis of Task Types and Error Types Involved in Human-related Unplanned Reactor Trip Events

As the number of the unplanned reactor trip due to human erroneous actions increases, interest in reducing such unplanned reactor trip events has been recently drawn. During the year of 2002 - 2006, unplanned reactor trip events due to human error take 23 % of all unplanned reactor trips, and more recently during 2005 - 2006 it increased to amount to 40 %. As an initial effort for analysing vulnerabilities related to the tasks and environments during plant normal operations, the human-related unplanned reactor trip events that happened during 1986 - 2006 have been analysed preliminarily in view of task types and error types