Potential Applications and Recommendations of Dynamic Event Tree Analysis using DICE(Dynamic Integrated Consequence Evaluation)

Abstract

Over the past six years, Kyung Hee University has completed the development of DICE (Dynamic Integrated Consequence Evaluation), a dynamic event sequence analysis tool. For the analysis of design basis accidents, the tool incorporates the MARS-KS, a regulatory verification code in Korea, while for severe accident analysis, it integrates the MELCOR from the U.S. NRC as its physical module. The tool comprises a diagnosis module for determining control tasks, a reliability module for assessing their functionalities (normal/abnormal), and a scheduler has been configured to exchange inputs and outputs between these modules at a specified interval. Each module is structured as dynamic link libraries to ensure flexible extension with the scheduler. By following to the specified data structure protocol defined by DICE, the integration of external modules becomes relatively straightforward. This paper explores leveraging these structural features to propose potential applications for risk assessment, where both DSA (Deterministic Safety Analysis) and PSA (Probabilistic Safety Assessment) are conducted within a unified computational process. The paper suggests enabling approaches for addressing challenges that are difficult under conventional PSA, such as complex multi-unit assessment, cyber security, autonomous operation development, and so on. Based on these benefits, authors discuss considerations for standardizing the dynamic event sequence analysis.