Challenge of Nuclear Governance 1. “Failure” of Interdisciplinary Communication Advances in tsunami research since around 2002 have made the uncertainty of tsunami predictions more obvious in the tsunami experts’ community. Nevertheless, their recognition of uncertainty was not transmitted to the nuclear safety community 2. “Failure” of Voluntary Safety Efforts Accident management measures were been basically regarded as voluntary efforts by operators, not legal requirements. It was decided that the PSA (probability safety assessment) limited its subject to internal events, and excluded external events including earthquakes because of operator’s considerations from the viewpoint of public acceptance in siting areas 3. Issues for future nuclear governance Integrative capacity to deal with complex risks Independent expertise for nuclear safety in civilian use