The primary objective of government policy, and of NUMO in implementing this policy is to ensure that a repository for Japan’s high-level radioactive waste is designed and located so as to provide secure isolation of the waste and adequate safety for present and future generations. This requires that the site of a repository has to be chosen carefully and an associated repository concept is selected which is appropriate for its specific geological and environmental conditions. At NUMO, we have chosen to implement a volunteering approach to siting.