
French-Dutch start-up Thorizon is partnering with the MatéIS (Matériaux Ingénierie et Science) engineering and science materials laboratory at French engineering school Insa de Lyon, and the Curium company in Montagny, to study how materials behave in contact with molten salts.
In March, Thorizon, a spin-off from the Nuclear Research & Consultancy Group (NRG), secured funding to accelerate the development of its advanced small modular reactor (SMR) Thorizon One. The 100 MWe/250 MWt Thorizon One molten salt reactor design will use long-lived nuclear waste as fuel. In 2024, Thorizon and Stellaria in a consortium with Orano, were selected as winners of the call for projects to develop molten salt reactors under France’s 2030 Innovative Reactor Programme. Thorizon aims to launch construction of the reactor in 2030.
By leveraging the expertise and equipment of the MatéIS Laboratory and the Curium company, Thorizon hopes to evaluate the behaviour of materials exposed to molten salts, mainly with respect to corrosion. Thorizon says the collaboration gives it access to dedicated research spaces in the Auvergne-Rhône-Alpes region of France, enabling it to expand its R&D efforts.
“A first corrosion loop will be installed in September and several more will follow, said Laure Claquin, Director of Operations at Thorizon. “Then, in 2026, we should set up validation loops. Our goal is to file an application for authorisation to create our molten salt reactor at the end of 2027.”
She added: “Today, the company has funds to deploy corrosion loops, the cost of which ranges from €50,000-100,000 ($57,000-114,000).”We raised €12m in 2022 and then €16m in March. We also received €10m from France 2030 and €4m from the Netherlands.” Further fundraising will be needed for validation loops.
Future Thorizon One units, priced at an estimated €500m, are intended for several markets. “We will target data centres and industrial heat”, said Claquin. “Fossil fuels currently account for 70% of energy consumption. Nuclear power is essential for a successful energy transition because it is the only decarbonised, controllable and permanent solution.”
Thorizon says that, as the project develops, the work will progress from testing material samples to testing complete sub-systems to confirm the performance and reliability of critical components, paving the way for commercialisation and deployment. The company says it is conducting pre-feasibility studies at three nuclear-designated sites in France, Belgium and the Netherlands.
“Collaborating with Curium and MatéIS allows us to benefit from their unrivalled expertise in materials and corrosion testing,” said Thorizon CEO Kiki Lauwers. “It gives us access to specialised testing capabilities and will be a key step in closing the gap between concept and commercial readiness. This is just the latest in our transformative journey in France, where we are committed to growing our footprint, deepening local partnerships, and strengthening our roots in Europe’s energy future.”