Dutch and French regulators collaborate on Thorizon’s molten salt reactor preparatory review

The Dutch nuclear safety authority ANVS and the French nuclear safety authority ASN with IRSN, its technical support organization, have agreed to collaborate on a preparatory review of the Thorizon One molten salt reactor project.

This review will take place through a series of joint technical meetings starting this autumn to present simultaneously to both authorities the Thorizon One reactor ahead of pre-license applications expected at the same time in both countries in 2025.

This common preparatory review will aim at:

Understanding the specific design of this reactor, its safety approach and associated research and development program.
Defining the scope of the pre-license applications to be sure to focus the assessment resources on the most significant safety challenges of the Thorizon One reactor project.

This preparatory review performed at an early stage of the development of the Thorizon One design is expected to increase the efficiency of the future pre-licensing applications in both countries. The review is an important step toward the first deployment of the molten salt reactor.

Grateful for this unique opportunity

Kiki Lauwers, CEO of Thorizon, states, “Thorizon is pleased to advance its molten salt reactor design. The early feedback from both nuclear regulators is invaluable for demonstrating the safety of the Thorizon One reactor. This multi-country cooperation will facilitate deploying the reactor in multiple countries in the future. I would like to thank the French safety authority ASN and the Dutch safety authority ANVS for leading this preparatory review process and IRSN for supporting it. We are committed to delivering a safe, cost-competitive reactor that contributes to the energy transition responsibly with the lowest possible footprint.”

A disruptive nuclear technology offering benefits in circularity, safety, and costs

Molten salt reactors (MSRs) are internationally recognized as a promising new nuclear technology that enhances the circularity of nuclear energy by recycling spent nuclear fuel, thereby reducing long-lived nuclear waste. Their inherent safety characteristics are expected to lower construction costs. In the reactor core, a molten salt mixture containing fissionable materials acts as both the fuel and the coolant, eliminating meltdown scenarios by keeping the fuel in a molten state. Additionally, the reactor operates at or near atmospheric pressure.

Collaboration between France and the Netherlands on multiple dimensions

The Thorizon One molten salt reactor project aligns with the fuel recycling strategy, memorandum of understanding between nuclear regulators, and the innovation pact shared by France and the Netherlands.

Fuel Recycling Strategy: Currently, France and the Netherlands are committed to recycling their spent nuclear fuel, reducing nuclear waste and deep storage of scarce resources. The treatment and recycling service is conducted by Orano, the recognized international group with a unique expertise in the field of nuclear materials valorization, which will also develop the fuel for the Thorizon One reactor.
Nuclear Regulators: This project falls under the memorandum of understanding signed in September 2023 between the French ASN and Dutch ANVS, aimed at collaborating on regulatory initiatives, including the licensing of nuclear installations such as small modular reactors (SMRs), and sharing experiences on new and innovative technologies.
Innovation Pact: In April 2023, the Ministries of Economic Affairs of France and the Netherlands signed a pact to collaborate on innovation and sustainable growth, including nuclear technology, to strengthen public-private cooperation around concrete projects. The molten salt reactor project contributes to low-carbon energy and the decarbonization of industrial processes.

European Project led by a Dutch French start-up

The Thorizon One, a 250MWth or 100MWe molten salt reactor, can provide flexible electricity for 250,000 households or industrial heat at 550 degrees Celsius. Thorizon, a spin-off from the Dutch Nuclear Research Institute (NRG), with offices in Amsterdam and Lyon, is developing this innovative reactor. Invest-NL, the Dutch National Promotional Institute, is a shareholder of Thorizon and the company’s project, in consortium with Orano, received a €10 million grant from the French State under the France 2030 “innovative nuclear reactors” investment plan. Thorizon collaborates with renowned entities such as Orano and EDF in France, NRG and DIFFER in the Netherlands, the high-tech manufacturing industry in both countries and Tractebel in Belgium.

Starting construction in the early 2030s

Thorizon aims to contribute to Europe’s goal of climate neutrality by 2050 and develop small modular reactors by the 2030s, envisioning the first molten salt reactor in Europe to be operational by 2032. Licensing is a critical path in this timeline, making early dialogues with regulators essential. To streamline the licensing process, Thorizon One plans to comply with existing safety regulations, use licensed materials and components, and work with experienced companies with prior nuclear licenses. Thorizon has recently hired two renowned licensing experts: Antoine Claisse, previous licensing manager for the ITER fusion project in France, and Marco Visser, previous licensing manager for the Pallas research reactor in the Netherlands.

About Thorizon

Thorizon has rapidly evolved from a spin-off of NRG (Dutch Nuclear Research Institute) into an ambitious deep-tech startup, with offices in Amsterdam and Lyon. The company views small modular nuclear reactors as an ideal, stable, and clean contributor to an energy system where wind and solar are the other important sources. The ambition is to develop a reactor based on molten salt that can be realized rapidly and smartly, is ’walk-away’ safe, and takes a first step towards circularity by using long-lived nuclear waste as a fuel source. Thorizon is working to further strengthen its financial position to be able to build a non-nuclear molten salt demonstrator in the short term and finalize the detailed design to start building a first-of-a-kind reactor by 2030: the Thorizon One. Thorizon partners with industry leaders like Orano, Tractebel and EDF to advance its design and is a laureate in the France 2030 investment plan for innovative nuclear reactors. For more information about Thorizon, you can visit www.thorizon.com .

Project funded by the French State under the France 2030 plan