The Recycling of Nuclear Fuel and High Level Radioactive Waste

High-level waste arises from the reprocessing of spent fuel used in nuclear power plants

One third of the electricity we consume in Japan today comes from nuclear power.
Resolving the issue of disposing of this waste safely and reliably is the challenge now facing NUMO.

The nuclear fuel cycle and high-level radioactive waste

Because glass is hard to dissolve and is chemically stable, radionuclides can be confined in a glass matrix for long periods of time.

High-level radioactive waste
Liquid waste is concentrated and mixed with molten glass in a stainless steel fabrication canister where it solidifies into a stable form

High-level waste encapsulated in stainless steel fabrication canisters requires to be stored for 30 to 50 years to allow cooling.

Controlled interim storage facility for high-level waste

High-level waste will be disposed of in a stable geological formation at a depth of more than 300 meters. The vitrified waste in fabrication canisters will be encapsulated in strong metal containers (overpacks) and, once emplaced in the repository, will be surrounded by a clay buffer material. The canisters, overpacks and clay buffer material are referred to as the engineered barrier system. The geological environment, which isolates the waste for long time periods, is termed the natural barrier. The multibarrier system used for safe waste disposal is a combination of engineered and natural barrier. Research and development on the multibarrier system will continue with a view to building confidence in this concept.