TerraPower targets 2034 UK start for Natrium reactor, its first abroad

TerraPower expects UK power output from its Natrium technology by 2034, according to chief executive Chris Levesque in a statement to Reuters. Each Natrium unit is a sodium-cooled small modular reactor (SMR) producing 345 megawatts of baseload power, with molten-salt storage capable of boosting output to 500 MW for over five hours. That timeline hinges on progress at the first Natrium plant, under construction in Wyoming and due for completion in 2031, which Levesque says makes a 2034 UK start 'very feasible'.

The push follows the UK government's Advanced Nuclear Framework, launched this year to back privately funded SMR projects as part of its energy security and climate strategy. TerraPower's design is currently going through the UK's Generic Design Assessment (GDA), the regulatory process run by the Office for Nuclear Regulation that all new reactor designs must clear before deployment. Levesque told Reuters the company's British subsidiary is likely to be based in Liverpool, close to the regulator, though no UK site for the reactor itself has been chosen.

What this means for UK power buyers

UK baseload day-ahead power over the past year gives buyers a benchmark against which Levesque's sub-£100/MWh target for the 2030s can be judged.

For commercial energy buyers, this is a signal about the long-term generation mix rather than an immediate procurement lever. Natrium reactors use high-assay, low-enriched uranium (HALEU), a fuel previously sourced almost exclusively from Russia; both the UK and US are now building domestic HALEU supply chains, which is itself a multi-year infrastructure build worth tracking. Levesque said Natrium electricity should compete with combined solar-and-battery systems at under £100/MWh, a cost benchmark buyers modelling 2030s power procurement should note.

• First Natrium unit (Wyoming) targeted for completion in 2031
• UK Generic Design Assessment (GDA) review currently underway
• Likely UK subsidiary location: Liverpool, near the nuclear regulator
• Target cost: under £100/MWh, competitive with solar-plus-storage
• HALEU fuel supply chains being built in both UK and US
• No UK reactor site yet confirmed

In the US, TerraPower has partnered with Meta on plans for up to eight reactors, and Levesque indicated similar corporate tie-ups could follow in the UK. The Guardian's environment coverage has tracked the broader SMR push as part of the UK's route to Net Zero, alongside competing technologies from other developers.

Nothing here changes 2026 or 2027 procurement decisions. The story to watch is site selection, expected once the GDA process advances, and whether TerraPower announces a UK corporate offtake partner along the lines of its Meta deal, which would be the clearest signal of commercial momentum behind the 2034 target.