After the temporary storage for 30-50 years, HLW will be laid and disposed of in a stable geological formation at a depth of more than 300 meters so as not to pose a threat to either human beings or the natural environment. The disposal adopts a multiple barrier system. Overpacks and their surrounding butter clay work as artificial barriers and stratums work as natural barriers to prevent radioactive materials from leaking.
In Japan, the "Specified Radioactive Waste Final Disposal Act" was passed in June 2000, and the Nuclear Waste Management Organization (NUMO) was established as the implementing organization for the HLW final disposal project in October 2000.
NUMO is now inviting municipalities to volunteer as candidate site for repository.
NUMO (Nuclear Waste Management Organization)