Thorizon Initiates Joint Review with Dutch and French Regulators for Molten Salt Reactor Licensing

Thorizon, a company based in the Netherlands, has announced a collaborative effort between Dutch and French nuclear regulators to conduct a preliminary review of its Thorizon One molten salt reactor. This collaboration is intended to streamline the pre-licensing processes scheduled for next year. The Dutch Authority for Nuclear Safety and Radiation Protection (ANVS) and the French nuclear regulator, Autorité de Sûreté Nucléaire (ASN), together with the Institute for Radiological Protection and Nuclear Safety (IRSN), have agreed to jointly assess the Thorizon One reactor. The goal of this review is to evaluate the reactor's design and safety aspects, helping to smooth the path for future licensing in both countries.

The review process will involve a series of joint technical meetings starting in the near future, during which the Thorizon One reactor will be presented to both authorities. These meetings are intended to pave the way for the pre-licensing applications, which are expected to be filed concurrently in both countries by 2025. The primary aim of this joint review is to fully understand the reactor's design, safety strategies, and related research and development efforts. Additionally, the review will help define the pre-licensing application’s scope, ensuring that resources are directed towards addressing the reactor's key safety challenges, thereby making the future licensing process more efficient in both nations.

Thorizon’s CEO, Kiki Lauwers, expressed satisfaction with the progress of the molten salt reactor's development. He noted that early feedback from both regulators is crucial for demonstrating the reactor’s safety, and that this cross-country cooperation could facilitate the future deployment of the reactor in various regions. Thorizon also highlighted that this project aligns with a memorandum of understanding (MoU) signed by ASN and ANVS in September last year, which promotes collaboration on regulatory matters, including the licensing of nuclear facilities like small modular reactors (SMRs), and the exchange of knowledge on innovative technologies.

Thorizon, a spin-off of NRG, the operator of the High Flux Reactor in Petten, is working on a 250 MWt/100 MWe molten salt reactor designed for large industrial clients and utility providers. The company aims to have the first MSR in Europe operational by 2032. Thorizon emphasized that the licensing phase is a critical milestone in this timeline, and early discussions with regulators are key to expediting the process. To ensure a smooth licensing process, Thorizon One plans to comply with existing safety standards, use approved materials and components, and partner with experienced companies familiar with nuclear licensing procedures.

Molten salt reactors (MSRs) utilize molten fluoride salts as their primary coolant and operate at low pressure. They can function with either epithermal or fast neutron spectrums and are capable of using a variety of fuels. Renewed interest in MSRs stems from their potential to use thorium to breed fissile uranium-233, although an initial supply of fissile material like plutonium-239 is required to start the process.‍