Decommissioning of Beznau nuclear power plant

After extensive review work, Axpo decided on 4 December 2024 that Unit 2 of the Beznau Nuclear Power Plant (KKB) will remain on the grid until 2032 and Unit 1 until 2033. After that, they will be taken out of service and decommissioned. This decision was made taking into account the technical, organisational, regulatory and economic aspects.  

The Beznau nuclear power plant has been connected to the grid since 1969 and produces almost 6 terawatt hours of electricity per year safely and with low emissions, with a high proportion of winter. This corresponds to the consumption of 1.3 million four-person households. In this way, the plant and its employees will make an important contribution to security of supply in Switzerland until it is decommissioned.

KKB employees are central to Axpo. Decommissioning and dismantling are carried out as far as possible with the company's own employees. In addition, additional recruitment and the commissioning of third parties will be necessary. 

For the final decommissioning of a nuclear power plant, operators must draw up a decommissioning project and  submit it to the Swiss Federal Office of Energy (SFOE). The SFOE coordinates the decommissioning procedure and obtains the opinions of various federal authorities, including in particular the ENSI, FOEN, ARE and cantonal authorities. If this assessment is successful, the responsible Department of the Environment, Transport, Energy and Communications (DETEC) issues the decommissioning order.

ENSI monitors not only the operation of the nuclear power plants, but also all decommissioning work from post-operation to completion of dismantling. The protection of the population, personnel and the environment is also guaranteed at all times during the decommissioning of nuclear power plants.

The decommissioning of nuclear power plants has been solved from a technical point of view and is carried out in proven and safe procedures. More than 200 plants have already been shut down worldwide. For specially required work, there are specialized companies with great experience.

The decommissioning will begin with the final cessation of power operation. During nuclear dismantling, the plant will be dismantled step by step until all radioactive material has been removed from the site and ENSI confirms that the plant is no longer a source of radiological hazards. The dismantling of the Beznau NPP will take until the mid-2040s. A precise schedule will be worked out with the decommissioning project. The site of the power plant site can then be reused. 

Nuclear dismantling takes place from the inside out. First, the fuel assemblies are removed from the plant and packed in transport and storage containers. Since the Beznau nuclear power plant operates its own interim storage facility (Zwibez) at the site, there is no need for the usual transport to the central interim storage facility (Zwilag) in Würenlingen. Low- and intermediate-level industrial waste is also professionally packaged and largely taken to the Zwibez. A small proportion of the waste goes to Zwilag. When all the fuel elements from the nuclear power plant have been moved to the Zvivets after about four years, the most important source of radioactivity will also have been removed from the reactor building. Even at an early stage, systems and plant components are decommissioned or adapted to the new requirements. 

During dismantling, the non-radioactive materials are sorted out and recycled or disposed of like conventional waste. Materials on which radioactive substances have been deposited are cleaned (decontaminated) and, after clearance measurement, are also recycled or disposed of as far as possible in the conventional ways.

Only a small part of the dismantling material is later transported to the deep geological repository of Nagra (National Cooperative for the Disposal of Radioactive Waste).

About nine years after the fuel element was free, the plant is completely free of radioactive material. A little later, the authorities were able to officially determine that the KKB was no longer a source of radiological danger. The site of the former nuclear power plant will then be considered a normal industrial area and will continue to be used. The subsequent use is still open. The Zwibez will remain on the site until the waste is transported to the deep geological repository. Afterwards, the Zwibez will also be dismantled. 

The financing of post-operation, decommissioning and disposal of radioactive waste is comprehensively regulated and secured by law in Switzerland. Axpo, as the operator of the KKB, bears all costs associated with post-operation, decommissioning and disposal. To this end, Axpo pays into two funds monitored by the federal government during operating hours: the decommissioning fund and the waste disposal fund. The post-operating costs for the period between the final cessation of power operation and the absence of nuclear fuel will be borne directly by Axpo.

Details on financing can be found on stenfo.ch.