Switzerland: The World’s Oldest Operating Nuclear Power Plant Extended

Swiss energy company Axpo has announced the extension of operations at the Beznau nuclear power plant in the canton of Aargau. With an investment of 350 million Swiss francs, the plant’s two units will remain operational until 2033.

The momentum for a nuclear revival in Switzerland is gaining ground. In August 2024, the Swiss government signalled its intent to potentially reconsider the law prohibiting the construction of new nuclear power plants as part of the nation’s strategy to achieve net-zero emissions by 2050. Albert Rösti, the Minister of Environment, Transport, Energy, and Communications, supported this initiative by proposing Mühleberg as a potential site for a new nuclear project.

Against this backdrop—though independently of any federal decisions—Swiss energy group Axpo announced in December 2024 the extension of Beznau’s operational life until 2033. Beznau has held the distinction of being the world’s oldest operating nuclear power plant since the closure of the Oldbury plant in the UK in 2012.

Operational for Several More Years

In Switzerland, nuclear plants are not subject to a fixed operational lifespan. They are permitted to operate as long as safety standards are met. The Beznau plant comprises two Westinghouse-designed pressurised water reactors (PWRs), each with a capacity of 365 MWe. Unit 1 began operations in 1969, and Unit 2 followed in 1972, making them 55 and 52 years old, respectively. With a 350-million-Swiss-franc investment (over 376 million euros), both units will surpass 60 years of operation.

“Axpo has decided that Unit 2 of the nuclear plant will remain connected to the grid until 2032, and Unit 1 until 2033. They will then be decommissioned and dismantled. This decision was made based on our social responsibility as well as technical, organisational, regulatory, and economic considerations,” Axpo stated in a press release. This decision follows a feasibility study initiated in April, conducted in cooperation with the Federal Nuclear Safety Inspectorate (ENSI).

A Modernised Plant

The Beznau nuclear plant had previously received 2.5 billion Swiss francs in investments for modernisation. It generates approximately 6 terawatt-hours of electricity annually, sufficient to supply 1.3 million households of four people. Additionally, the plant contributes to district heating (cogeneration) for around 20,000 people in its surrounding area. ■