Switzerland’s Council of States (the upper house of parliament) has approved the government’s proposal to amend the Nuclear Energy Act, which would repeal provisions that currently prohibit general licences for new nuclear facilities. The upper house passed the measure with 27 votes to 13, with two abstentions. The proposal now moves to the National Council (the lower house) for debate.
Parliament has until August to make a final decision on both the government’s legislative amendment and a separate popular initiative known as the Stop the Blackout initiative. The popular initiative, launched in 2024, seeks to amend the Swiss Constitution to guarantee “technology neutrality”, effectively mandating that nuclear power remain an option.
The Swiss Federal Council (executive branch) prefers a legislative change to the Nuclear Energy Act rather than a constitutional one, arguing that it is a faster and more flexible route. If both chambers of Parliament approve lifting the ban on nuclear construction, opposition parties (the Greens and Social Democrats) have already indicated that they will launch a referendum to challenge the decision. A nationwide plebiscite on the issue is currently expected for 2027.
For now, Switzerland remains committed to a gradual nuclear phaseout, a policy approved by voters in 2017 in the wake of the 2011 Fukushima disaster in Japan. Switzerland still has three ageing nuclear plants with four reactors – Beznau 1&2, Gösgen and Leibstadt – which together produce about 30% of its electricity.
Beznau 1&2, owned and operated by Axpo, are 365 MWe pressurised water reactors (PWRs) that began operation in 1969 and 1972. Gösgen, a 1,010 MWe PWR that began operation in 1979, is operated by Alpiq, which is responsible for the company’s management. Axpo holds a 37.5% minority interest in the plant. Leibstadt is a 1,233 MWe boiling water reactor that began operation in 1984. It is operated by Kernkraftwerk Leibstadt AG, with Axpo serving as the managing director and holding a majority 52.7% stake.
Following the decommissioning of the Mühleberg NPP in 2019, these units are being managed for extended operation, potentially up to 60 or even 80 years. Switzerland aims to become climate neutral by 2050, which means replacing fossil fuel heating systems and combustion-engine cars with electric alternatives, driving up electricity demand. New nuclear plants could help to close the looming energy supply gap with a low carbon footprint. Concerns about blackouts and climate targets are increasingly outweighing the safety fears provoked by the accident. In addition, new reactor designs promise to be cheaper and safer.
Financing may nevertheless be an issue. Cost estimates for a new plant in Switzerland are CHF15-25bn ($19.2-32bn) and state guarantees or subsidies would be needed. Even if the ban is lifted in 2026, it does not mean immediate construction. Major utilities such as Axpo have stated that while they support “technological openness,” they currently have no concrete plans or funding to build new plants due to high costs and regulatory risks.
