On 27 January 2022, the Swedish government decided to permit a final repository of spent nuclear fuel and an encapsulation plant needed to handle such spent nuclear fuel in Sweden. The government has also found the environmental impact of the repository to be acceptable. Sweden is thereby the first country in the world to allow the final disposal of spent nuclear fuel.
Background
The discussion concerning the final disposal of nuclear waste has been ongoing since Sweden's first research reactor was activated in the 1950s. The Swedish Nuclear Fuel and Waste Management Company (SKB) was founded by the nuclear power industry to find a solution for Swedish nuclear waste, which is currently placed in water tanks for intermediate storage at the nuclear power plant of Oskarshamn.
In final disposal, nuclear waste is meant to be safely stored for hundreds of thousands of years. As the waste is harmful and radioactive, it takes a long time for the radioactivity to decrease.
In 2011, SKB applied for a permit to build and operate facilities in a cohesive system for the final disposal of spent nuclear fuel. The system consists of a facility in the municipality of Oskarshamn for intermediate storage and encapsulation of spent nuclear waste, and a facility for disposal in the bedrock of Forsmark.
The application for final disposal was submitted with the Land and Environmental Court at Nacka District Court as well as with the Swedish Radiation Safety Authority. This is because permission is required according to both the Environmental Code and the Nuclear Activities Act. After thorough examination and preparation, the applications were submitted in January 2018.
A central part of the process has been to involve all concerned stakeholders and allow them to offer their opinions. Authorities, researchers, environmental organisations, concerned municipalities and the general public have been allowed to give feedback. A great number of opinions have been submitted to the government, spanning several tens of thousands of pages.
The government has now assessed that the application, after revision, fulfils the requirements of the Environmental Code and the Nuclear Activities Act. Therefore, SKB has been granted permission to hold, construct and operate a spent fuel repository and an encapsulation facility.
Safe method of final disposal
Methods of final disposal have been thoroughly investigated and researched since the 1970s. The method that has now been approved, KBS-3, is a Swedish-developed, world-leading technology for the disposal of nuclear waste. The method relies on three barriers: copper canisters, bentonite clay surrounding the canisters and the bedrock itself. Together, they protect humans and the environment from harmful radiation.
The first barrier, the copper canisters, constitutes the capsules' corrosion-barrier and is constructed to withstand the mechanical strain produced by possible movements in the bedrock. To further separate the nuclear fuel, the capsules are surrounded by bentonite clay, which constitutes a buffer. The role of this buffer is to both minimise groundwater reaching the capsule wall and prevent radioactive substances from seeping out in the event of a leak. The final barrier, consisting of 500 metres of bedrock, is meant to isolate the waste and keep it separated for at least 100,000 years. If a capsule were to break, the bedrock would delay the radiation from reaching the surface.
The final repository in Forsmark consists of 500 tunnels at a depth of 500 metres in the bedrock and will hold 12,000 tonnes of spent nuclear fuel, packaged in 6,000 copper capsules.
The government has assessed that this method is the best one available and that the barriers ensure sufficient safety under relevant acts and ordinances, even over a very long time.
Comment
A great deal of work is still needed before the final disposal of nuclear waste is in place. Method development will be presented during upcoming safety briefings under the conditions of gradual assessment in the approved environmental permit. Technical questions and details are not a hindrance in beginning the final disposal, but further research and development will be required. Questions about how knowledge and information shall be transferred to future generations will need further investigation.
It is expected to take around 70 years until all nuclear waste is disposed of. In 70 years, when the final repository is constructed and all capsules are disposed of, the incumbent government will assess whether the repository can be finally sealed.
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