Final disposal of vitrified residues in Japan

After the interim storage period, allowing for the decay of most short-lived fission products and thus the cooling of the vitrified high level waste, the canisters can be disposed of in a deep geological site for isolation from the biosphere.

Geological disposal of high level and long-lived waste is recognised world-wide as a technically sound concept. The multiple barriers enclosing the waste, that is to say the borosilicate glass itself, the canister as well as other engineered barriers, and the rock formations surrounding the repository (natural barrier) will prevent a return of radioactivity from the waste to the human environment over a very long period.

Japan is undertaking such a programme, which involves several successive careful actions, to design and construct the most suitable repository site in terms of technical feasibility, environmental impact, economic considerations and public acceptance.

Technical developments are being continued by dedicated organisations. It is expected that repository operations will start by 2030s or mid-2040s at the latest.