Mühleberg will be the first nuclear power station to be dismantled
The operating company BKW unveiled its decommissioning plan this spring. The Mühleberg nuclear power plant near Berne will be taken out of operation in three and a half years’ time on 20 December 2019. This is an unprecedented event as it is the first time in Switzerland that a nuclear power station will be demolished. Until now only research reactors have been dismantled.
The power company BKW intends to draw upon experience in Germany for the first decommissioning of a nuclear power plant in Switzerland. The nuclear power stations of the former German Democratic Republic were shut down shortly after reunification by Switzerland’s northern neighbour. A second wave of nuclear plant decommissioning took place after Fukushima. Germany had to learn the hard way when undertaking such projects. In the case of the six East German reactors in Greifswald, demolition work has already taken two decades, with no end in sight. BKW hopes to do a better job at Mühleberg. Firstly, a rigid timeframe should keep costs down, which represents a huge challenge. Such facilities remain nuclear plants even after decommissioning. The fuel rods must die down for five years in the water of the fuel pool before they can be transported away in special containers, known as CASTORS. To start demolition as quickly as possible after decommissioning, BKW will install a separate cooling system for the fuel rod pool once the plant has been taken out of operation.
The fuel rods will be taken to the interim storage site in Würenlingen, Aargau, in 2024. A nuclear accident in Mühleberg will then no longer be possible. However, the plant will still contain lots of contaminated concrete and steel. This will be broken up and also transported to the interim storage facility. Some will be purified until it is free of radiation to the extent that it can be reused. The plant will be dismantled from the inside outwards. The most complex part – the removal of contaminated material – will be carried out first.
The Mühleberg plant should be free of nuclear materials by 2031. The dismantling also involves the regular demolition of buildings, which is set to be completed by 2034. There should then be no trace of the former nuclear power station in Mühleberg. Whether the site on the Aare will be returned to green meadowland, though, has not yet been decided. It could remain an industrial area.
Even if everything runs to plan, the demolition of the Mühleberg nuclear power station will take 15 years – three times longer than its construction. BKW estimates costs of 800 million Swiss francs. A further 1.3 billion francs hasbeen earmarked for the disposal of nuclear waste. The nuclear waste should be disposed of in the final repository from around 2040, where it will remain for thousands of years. Where the final repository will be located remains to be decided conclusively in Switzerland.