[en] The purpose of this study is the development of effective and overall assessment methodology which reflects the characteristics of plants for the surveillance, maintenance, repair and operation of Nuclear Power Plants. In this study, the configuration risk evaluation methodology was suggested and applied to domestic plant as apart of development of assessment methodology for plant configuration control. The probabilistic model for component aging was developed also. Configuration control assessment methodology suggested in this study for the purpose of the development of configuration control methodology reflecting the characteristics of Korean NPPs, can be utilized as the supplement of current PSA methodologies