Final disposal of nuclear waste

Many countries that use nuclear energy have disposal facilities for low- and intermediate-level nuclear waste. However, no country has yet started operating a final disposal facility for high-level waste disposal.

In addition to Finland, many other countries with nuclear power plants have research and development programmes aimed at finding a solution for the final disposal of high-level nuclear waste. 

Disposal of low and intermediate level waste

The final disposal of low- and intermediate-level waste generated in the operation of nuclear power plants is a well-established practice in Finland and internationally. Disposing intermediate- and low-level nuclear waste has been done around the globe since the 1950s, and disposal is currently ongoing at more than 80 disposal facilities.

Nowadays, mainly two types of final disposal solutions are used: a concrete bunker in the surface layer of the ground or a site excavated in bedrock at a depth of 50–100 metres. The biggest difference between the two methods is that a disposal facility located in the surface layers requires monitoring for a few hundred years after the decommissioning of the facility. On the other hand, ensuring the safety of a final disposal facility built into bedrock does not need monitoring after the facility closes.

In Finland, the final disposal facilities for low- and intermediate-level waste are located at the Olkiluoto and Loviisa nuclear power plant sites:

Options for the management of high-level waste

Spent nuclear fuel from nuclear power plants can be handled in two ways: it can be reprocessed, i.e. recycled to recover uranium and plutonium from it, or the fuel can be used only once, meaning that it becomes waste after its use. Reprocessing also produces high-level waste that must be isolated from nature for an extremely long time period. Spent nuclear fuel is not reprocessed in Finland. Currently, it is kept stored in water pools (SNF storage pools) located at nuclear power plant sites.

• One option for managing high-level waste could be separating very long-lived radioactive substances from the waste and disposing it through transmutation. However, new types of reactors and reprocessing based on advanced nuclide separation are required for nuclear transmutation. Even if it was possible to make large investments in the development of nuclear technology, such technologies are not expected to be deployed on a large scale.
• Supervised long-term storage has also been proposed as a solution to this waste. Eventually, though, this is only a temporary solution. The idea behind long-term storage is that the waste would be stored for an indefinite period of time in above-ground or near-surface repositories in hopes that better waste-handling methods would arise through technical developments. However, this long-term storage solution would largely hand over the responsibility for nuclear waste and its final disposal to future generations, which goes against the principles that have been set out in international recommendations. In addition, a long-term storage is in a more vulnerable position than a final disposal facility built into bedrock in cases of crisis or e.g. as potential targets of terrorism.
• The final disposal of high-level waste deep in bedrock is currently the only known feasible final disposal solution. Extensive research and development efforts have been focusing on finding solutions for this for over 40 years.