There are various technologies and installations for the treatment, conditioning and storage of all types of radioactive waste. For example, it may be compacted to reduce its volume or solidified if it is a liquid. Usually, it is placed in metal or concrete containers and then embedded in concrete. For very low-level waste, less robust packaging may be used.
For very low-level waste and low-level waste, there is international consensus that this can be safely disposed of in near-surface facilities at a depth of no more than 30 metres. The underlying assumption is that deposited radioactive waste will decay to background levels before institutional control is lost (within about 300 years). Near-surface facilities may be simple trenches or may comprise an array of reinforced concrete cells. Once filled, these trenches or cells may be closed with a concrete slab and then sealed with an impermeable sheath. Finally, the trench or cell will be capped with a layer of clay several metres thick to ensure the long-term confinement of the waste.
High-level radioactive waste requires disposal in deep, stable geological formations usually several hundred metres or more below the surface. One of these facilities is close to becoming operational in Finland, and two are under construction in Sweden and in France.
To optimise disposal costs, there are an increasing number of multinational initiatives to support national solutions through joint collaboration, programmes and knowledge transfer, as well as feasibility assessments of regional solutions both at international and EU levels.