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Swedish advanced-reactor developer Blykalla has applied for state support to build up to eight lead-cooled small modular reactors at Untra in Tierp municipality, its second SMR site in eastern Sweden — a week after filing the underlying construction application.
Up to 440 MWe of lead-cooled SMRs at Untra
Blykalla submitted a proposal on August 25 for a nuclear power plant at Untra featuring up to eight SEALER small modular reactors with total electrical capacity of up to 440 MWe. On September 2, its licence-holding subsidiary Untra Nuclear Power AB submitted the follow-up application for state aid, mirroring the state-support request Blykalla made earlier this summer for its planned six-unit park in Norrsundet, Gävle.
How Sweden's new state-aid framework works
Sweden's state-aid regime, in force since 1 August 2025, combines a state loan, a two-way contract for difference and a risk-sharing mechanism, with terms negotiated project-by-project and subject to European Commission approval under EU state-aid rules. The government has now received support applications from seven projects across five sites — a total of up to 3,700 MWe of new capacity — as Stockholm pushes toward its roadmap of 2,500 MWe of new reactors by 2035 and up to 10 large-scale-equivalent units by 2045.
SEALER-55 and a 2030s target
The reactor at the heart of both parks is SEALER (Swedish Advanced Lead Reactor), a lead-cooled SMR under development at Blykalla — a spin-off from KTH Royal Institute of Technology, formerly known as LeadCold — since 2013. The commercial SEALER-55 is designed at 140 MW thermal / 55 MW electric per unit. "The need for dispatchable power in this part of Sweden is significant and growing," CEO Jacob Stedman said. "Building small and modular means we can meet it close to where it arises, on sites that were not previously available for nuclear." Blykalla says the first reactor at Untra could enter operation in the first half of the 2030s if the review process is efficient.
Where Blykalla fits in Europe's SMR push
The Untra bid arrives during a busy month for European advanced nuclear, alongside Blykalla's earlier six-SMR application and a Newcleo-led consortium's plans for a floating nuclear plant. Sweden's centre-right coalition, in office since 2022, has explicitly bet on advanced reactors — including SMRs — to backfill retiring baseload capacity and support data-center, electrolyser and industrial-heat demand across the north of the country.
Reporting based on coverage from World Nuclear News, NucNet and the American Nuclear Society.