[en] For evaluating the design issues in the advanced MMI, we have studied the selection of evaluation issues, evaluation schedules, and the application method of evaluation results from the beginning of APR1400 MMI design project. For producing input for human reliability analysis, we proposed a new error taxonomy and approach to explain the new human error potential. In order to evaluate whether or not the lifetime of APR1400 I and C system meet 60 years, the lifetime of the system has been calculated by using failure rates in this research. In order to qualify the software of APR1400 protection system, the detail scope and contents are to develop the methods, to evaluate the design results using the methods, and to establish a database for the evaluation. In external vessel cooling strategy to maintain the reactor vessel integrity in a severe accident of the APR 1400, an evaluation methodology was developed, and the failure possibility of penetrations and failure mode of the reactor vessel penetrations have been estimated through experiments and analysis. Two types of experiments have been performed using alumina melt as a simulant and a sustained heating method using an inductor, and their results have been evaluated along with APR 1400 using the LILAC, the FLUENT, and the ABAQUS computer codes