France-based start-up newcleo has inaugurated its FASTER (Fuel process Assembly Storage Training and Enhanced Reality) centre in Chusclan, France (near the Marcoule nuclear site). This €10m ($11m) advanced nuclear fuel engineering, testing, and training hub represents a step forward for the company’s mixed uranium plutonium oxide (mox) fuel strategy.
Newcleo’s key projects are its lead-cooled fast reactor targeted for criticality in 2032 and a planned facility to produce mox fuel in France targeted for operation in 2030 – both still in the basic design stage, although pre-licensing processes are underway with UK, US and French regulators. However, these are purely pre-application and preliminary paperwork reviews. They evaluate mathematical models and safety theories, not a physical machine.
The LFR-AS-200 (Lead-cooled Fast Reactor – Amphora-Shaped, with 200 representing its electrical output in megawatts) uses molten liquid lead as coolant and runs on mox fuel fabricated from recycled legacy nuclear waste and surplus materials. The company has initiated the land acquisition process for its 30 MWe demo reactor in the Chinon region of France. Newcleo has explicitly told regulators that their 30 MWe reactor and the mox plant are “interdependent projects”. If one fails to get licensed, the other cannot function.
Since its launch in 2021, newcleo has been very active in fundraising and signing partnership and collaboration agreements. Its business now counts over 90 partnerships, with more than 1,000 employees based in 19 locations across France, Italy, the UK, Switzerland, and Slovakia, including three manufacturing facilities.
In Italy, newcleo is building a state-of-the-art R&D and Qualification facility at ENEA’s Brasimone Research Centre, where it has already completed the construction of OTHELLO, a 2 MW loop-type system to qualify key components and solutions of its LFR technology.
The site will also host PRECURSOR, a 10 MW lead-cooled non-nuclear test system designed to integrate all reactor subsystems up to the turbine, representative of commercial scale operations. The company plans to complete the construction of PRECURSOR by end of 2026 and to commission it in the early months of 2027. OTHELLO and, PRECURSOR are completely designed, procured and built by newcleo’s subsidiaries.
FASTER does not carry out commercial mox production. Its purpose is to develop the machinery and operating procedures needed for future facilities, allowing mechanical processes and equipment layouts to be evaluated without the use of nuclear fuel materials. Seven test facilities are already active on-site. They address critical phases of mox production, including powder dosing optimisation, glovebox ergonomics, pellet inspection, and fuel pin assembly. The centre supports newcleo’s fuel team of approximately 100 engineers and specialists. It leverages expertise from newcleo’s Italian subsidiary SRS Servizi di Ricerche e Sviluppo and and French precision weighing manufacturer Bonifait Pesage (the acquisition of which is slated for late 2026).
The primary purpose of FASTER is to de-risk the company’s broader goals supporting both reactor and mox fuel development and to streamline pre-licensing strategy with US regulators as the company looks to expand into the American market. A US fuel fabrication facility is being co-developed in partnership with US nuclear start-up Oklo.
While newcleo formally maintains 2032 as its target date for first criticality of the LFR-AS-30 in France, the realities of nuclear engineering and licensing suggest that this timeline faces massive headwinds.
Newcleo is attempting to license a Generation IV liquid-metal reactor through the recently restructured French regulator, the ASNR (Autorité de Sûreté Nucléaire et de Radioprotection). Reviewing a novel coolant (molten lead) and a fuel cycle (mox) that the modern grid has never used at scale involves years of safety audits. Even if newcleo submits their construction permit request by 2028, a four-year turnaround for approval and full construction seems unlikely.
History shows that the first reactor of any new design always suffers from supply chain bottlenecks, manufacturing flaws in specialised components and unexpected engineering hurdles. While lead has great safety properties, it is incredibly heavy and highly corrosive to steel at high temperatures. If the structural materials or coatings fail during testing in PRECURSOR over the next two years, the entire design phase will have to be paused and reworked.
To try and prevent the decade-long delays that plagued new Generation III+ reactors (such as the EPR at France’s Flamanville 3 or the AP1000 at US Vogtle), newcleo argues that its pilot reactor is miniscule in comparison and uses components, which can be entirely factory-fabricated and shipped by truck cutting down on-site construction time.
Moreover, liquid lead reactor technology is not new. Russia has operated lead-bismuth cooled reactors in submarines for decades and is currently building the BREST-OD-300 lead-cooled fast reactor. Newcleo is therefore leveraging existing thermodynamic data.
Finally, by building the non-nuclear PRECURSOR facility in Italy newcleo aims to solve all the mechanical, fluid-dynamics, and pump failures before breaking ground on a nuclear-regulated site in France.
However, while newcleo’s financial backing and rapid testing strategy are designed to move fast, a realistic industry assessment would suggest that pushing first criticality out toward the mid-to-late 2030s would be more realistic.
The Russian state nuclear industry began laying the groundwork for BREST-OD-300 in the 1990s and early 2000s, building on vast amounts of data from Soviet Alpha-class submarines. Even after the Breakthrough (Proryv) project was launched in 2011, the timeline repeatedly slipped. Originally targeted to go online by 2020, then 2026, the launch date has now been pushed back to 2029 because of the extreme R&D challenges associated with building a first-of-a-kind reactor.
If a fully funded, state-backed monolith like Rosatom, which controls its own steel mills, fuel plants, and regulators, took nearly two decades to get to 70% construction completion, a private startup faces a mountain of obstacles.
Newcleo faces three major problems that state-run programmes can usually absorb or bypass.
- Rosatom essentially works in lockstep with its regulator, Rostechnadzor. Newcleo, on the other hand, has to provide different Western regulators – France’s ASNR, the US Nuclear Regulatory Commission and the UK Office of Nuclear Regulation – with information from scratch. Newcleo recently had to wind down its UK reactor development operations to shift focus strictly to France and the US because the UK failed to provide the “substantial support” needed.
- A state enterprise can absorb massive cost overruns over decades. A private start-up cannot. While newcleo has raised an impressive €537m ($613m), building a nuclear reactor requires billions. An extended, multi-year regulatory loop could see investor patience and capital can run dry long before 2032.
- Rosatom manufactures its unique, massive multi-layer metal-concrete reactor vessels and internals entirely via domestic state enterprises. Newcleo has to piece together its supply chain through corporate acquisitions, buying specialised manufacturing companies in Europe while dealing with different commercial market realities.
An aggressive timeline from a private player will be lucky to survive contact with the physical reality of molten metal cooling and safety regulators inexperienced with the technology.
