Development of Operator Response Time Model for DICE (Dynamic Integrated Consequence Evaluation)

Integrated Deterministic-Probabilistic Safety Assessment (IDPSA) which can facilitate the time dependency has been actively executed. IDPSA can provide explicit consideration for dependencies among systems, components, plant states, and delayed times for the operator's actions based on a continuous or discrete-time basis. Discrete Dynamic Event Tree (DDET) methodology has been generally used in IDPSA research. In Kyung Hee University, DICE (Dynamic Integrated Consequence Evaluation), a dynamic reliability analysis tool using DDET, was developed as a supporting tool for DPSA research. The diagnosis module, one of the modules in DICE, monitors plant status and controls plant states by commanding operator actions through the combination and logic of physical variables. It is expected that operator actions such as success, omission, or commission would make huge variance along with an accident scenario. Therefore, as a presentative application, DICE attempts to investigate such variance in a systematic way. In this study, the operator model to provide action timing was developed on the basis of SPAR-H (Standardized Plant Analysis Risk Human Reliability Assessment) and the method how to use the operator model in DDET was proposed.