Deployable Energy's Unity demonstration reactor has successfully achieved initial criticality at the National Reactor Innovation Center located at Idaho National Laboratory - which means the US has achieved the presidential goal set last year of three microreactors under Department of Energy authorisation to achieve initial criticalities by 4 July 2026.
 

Valar Atomics' Ward 250 advanced reactor has completed a zero-power fuelled criticality demonstration, becoming the second to meet the 4 July deadline for the US Department of Energy’s Reactor Pilot Program.
 

TerraPower's Natrium 345 MWe sodium-cooled fast reactor with a molten-salt-based energy storage system has officially started the UK's Generic Design Assessment process.
 

The Japan Atomic Energy Agency, the UK's National Nuclear Laboratory and Rolls-Royce have signed trilateral memorandums of cooperation on advancing High-Temperature Gas-Cooled Reactors and the coated particle fuel to power them.
 

The US Department of Energy has formally approved Xcimer Energy's preconceptual design and technology development roadmap milestone for Athena, the company's architecture for fusion power plants.
 

The Japan Atomic Energy Agency and Kazakhstan's National Nuclear Centre have agreed to a new phase of their joint core safety experiments of fast reactors, which focus on severe accident mitigation measures for demonstration fast reactors.
 

US advanced nuclear technology developer X-energy has submitted an application to enter the UK's Generic Design Assessment process for its Xe-100 high-temperature gas-cooled reactor.
 

Holtec International's SMR-300 small modular reactor design can potentially be built, operated and decommissioned in a manner that is safe and secure, UK regulators have concluded after the design completed Step 2 of the Generic Design Assessment.
 

The UK's Cambridge Atomworks has signed a memorandum of understanding with engineering, management and development consultancy Mott MacDonald to work on the development of the Odin microreactor.