Deep Disposal: The Swedish Solution

Published Date: 24 November 2009

30 countries around the world currently operate over 430 nuclear reactors. Many of them are planning to expand their nuclear power programmes and some are already constructing new plants. In addition, many more countries have expressed an interest in introducing nuclear power to meet energy needs. But there is still no system in place for the permanent disposal of the spent nuclear fuel, which is generated by the nuclear power plants and is highly radioactive, remaining hazardous for up to 100 000 years. © L. Potterton/IAEA Two different management strategies are used for spent nuclear fuel. In some countries the fuel is reprocessed to extract usable material for new fuel - a process that also produces high level waste - while in others the spent fuel is simply considered as a waste product. In all countries with nuclear power the spent fuel or the high-level waste from reprocessing is currently being stored, either in water pools or in vaults and casks at storage facilities. © Areva, France; La Hague, France Although the current arrangements for storage are working satisfactorily, it is becoming increasingly important to find solutions for permanent disposal. One possible solution is to dispose of the high level waste deep underground in a so-called "repository" where geological conditions are stable and the waste can be isolated from humans and the environment. Waste management experts around the world agree that this method is the best and safest option currently available or likely to be available in the foreseeable future. © SKB/Mitte According to the IAEA, deep disposal in stable geological formations is the only sustainable way to safely manage the high-level waste. No geological repository has yet been built, but some countries, including Sweden, France, and Finland have found a location for a future repository. In others, such as the UK, Switzerland, Germany, Belgium, China and Japan research is being carried out for deep geological disposal. Scientists are working in deep underground research laboratories, such as the Grimsel Underground Laboratory in Switzerland. © Comet Sweden, where around 50 percent of the electricity is produced by nuclear power, recently announced that it has found a location for a repository for high-level waste at Forsmark, north of Stockholm. Research for deep disposal is being carried out at the laboratories of the Swedish Nuclear Fuel and Waste Management Company (SKB) in Oskarshamn. © L. Potterton / IAEA On the beautiful island of Aspo, surround by lakes and forests, SKB runs a visitor and information centre. The centre attracts around 10 000 people a year from all over the world and arranges tours for visitors from countries that are also considering this method of disposal. © L. Potterton/IAEA At the SKB visitor centre guests can learn about nuclear waste management issues and visit a unique underground laboratory where scientists are conducting research for the final disposal of high level radioactive waste from Sweden's nuclear power plants. © L. Potterton/IAEA A short bus ride under the Baltic Sea takes the visitors to an underground laboratory deep below the island. At a depth of 500 metres, they can touch rock that is 1.8 billion years old, taste 7 000 year-old-water and witness a "dress rehearsal" for the future disposal of spent nuclear fuel. © L. Potterton/IAEA The idea is to dispose of the waste in specially-made canisters in a system of tunnels, deep underground where there are stable chemical and geological conditions. © L. Potterton/IAEA And before being placed in holes in the floor of the tunnels, the canisters will be surrounded with circles of special clay to protect them from movements in the rock. The tunnels will be backfilled and the final barrier is the bedrock itself. © L. Potterton/IAEA And it's not just a case of finding the ideal location as far as the rock is concerned, but also a place where the local community is prepared to have the disposal site in their vicinity. A recent poll shows a high level of acceptance - around 80 percent - in the region where Sweden's repository will be located. SKB carries out extensive public information work and its message is straightforward - it is our waste, we need to deal with it and not leave it for future generations. © L. Potterton/IAEA At its canister laboratory in Oskarshamn, SKB has designed a multi-barrier system for the disposal of the spent fuel to prevent radioactive substances from reaching ground level. The thick, copper canisters that will contain the waste have been designed to withstand earthquakes and future ice ages. © L. Potterton/IAEA Finding a site for a final repository is a long process. Over the past three decades, SKB has been conducting extensive investigations at potential sites to find the best bedrock. The repository has to isolate the fuel for a very long time - 100 000 years, that's 4 000 generations. © L. Potterton/IAEA All going to plan the first spent fuel could be making its way 500 metres underground in 2023. The whole project is expected to cost around Euro 10 billion - with the costs being covered by the owners of Sweden's nuclear power plant - and ultimately by the electricity consumers. © L. Potterton/IAEA But nuclear waste is not just a Swedish problem, so international cooperation in geological disposal is important and the research facility in Sweden is part of a multi-national network of underground research laboratories that is operated by the IAEA. The Agency also organizes conferences, seminars and training courses on this topic and sends experts to advise countries on all aspects related to deep geological disposal. And it develops international safety standards for the management and disposal of radioactive waste. © D. Calma/IAEA