Swiss nuclear plant could cost up to 43 billion francs, study finds

Discrepancy with previous cost projections

The Swiss Academies of Arts and Sciences released an assessment examining the capital requirements and financial risks of building a new nuclear power plant in Switzerland. The report arrives ahead of a national referendum next year on lifting the legal ban on new nuclear builds. Previous figures circulated by industry and research bodies suggested significantly lower expenses. Energy utility Axpo estimated project costs at roughly 10 billion Swiss francs, while Paul Scherrer Institute researcher Andreas Pautz estimated 8 billion to 10 billion francs in the Neue Zürcher Zeitung for a facility matching the output of the Gösgen plant. Researchers at ETH also cited scenarios around 8 billion francs, assuming nuclear construction costs decline with repeated builds. The Academies project a substantially higher total, calculating a span between 14 billion and 43 billion francs, with worst-case scenarios reaching up to 45 billion francs.

Capital financing and government risk exposure

A principal driver of the higher calculation is the inclusion of financing costs for invested capital during a construction phase spanning many years, an element largely excluded from earlier estimates. Capital financing expenses add 20% to 30% to the final construction bill, while construction itself represents approximately 70% of a plant's total lifetime costs. Urs Neu, who heads the Energy Commission at the Swiss Academies of Arts and Sciences, noted that international experience shows private investors no longer fund nuclear installations without extensive state backing to absorb liabilities.

A new build would only be financeable with substantial state support.

The study calculated that the financial overrun risk alone lies in the double-digit billions of Swiss francs. Under current market conditions, this exposure would fall entirely on the federal government.

Reactor vendor options and cost models

The report evaluated recent construction projects in Europe and the United States and concluded that only two suppliers are practical for a plant to enter service by 2050: the American company Westinghouse and the French manufacturer EDF/Framatome. Geopolitical considerations exclude Russian and Chinese state enterprises, while South Korean and Japanese suppliers are unlikely to submit bids for a decision needed by the mid-2030s.

For a Westinghouse reactor sized at 1,250 megawatts (similar in scale to Switzerland's Leibstadt facility), total construction expenses range from 14 billion francs under industry targets to 25 billion francs if past project cost trends repeat. A larger 1,630-megawatt reactor from EDF/Framatome ranges from 21 billion francs in an optimistic scenario to 43 billion francs based on historical project cost escalations.

Observed costs have risen from power plant to power plant. The industry, by contrast, expects costs to decrease from plant to plant.

Political debate and project schedule

The report follows debate during the federal parliament's summer session, where the National Council initially resisted moves by Environment Minister Albert Rösti to overturn the construction ban. Lawmakers demanded clarity on nuclear financing before advancing the legislation, prompting Rösti to pledge a dedicated government report.

Achieving a finished power station by 2050 imposes a tight timeline. A tender must open by the early 2030s, followed by a final vendor selection by the mid-2030s. Groundwork and construction must commence around 2040. The upcoming public vote will determine whether the legal framework permits any preparatory steps to proceed.