Since the Fukushima accident, our society has been engaged in various dis- cussions on denuclearization and energy conversion. And such debates and cli- mate crises call for social change called energy conversion. The demands of these times allow for interdisciplinary discussions on nuclear power and nuclear energy. This issue is the risk of being human. From this awareness of the problem, this paper attempts to present a Christian ethical perspective for the energy conversion that is carried out in connection with nuclear power generation and nuclear energy. We try to understand nuclear energy and nuclear power, espe- cially in terms of generational justice with human public good (welfare). This pa- per examines the overall debate on nuclear energy and deal with how changes in energy policy will affect humans and human life. Thus, this study demonstrates that changes in energy policy are immediately a matter of human welfare and of tomorrow’s definition of human beings.