{"id":17345,"date":"2026-08-17T07:37:13","date_gmt":"2026-08-17T11:37:13","guid":{"rendered":"https:\/\/www.autonocion.com\/us\/?p=17345"},"modified":"2026-08-17T07:37:13","modified_gmt":"2026-08-17T11:37:13","slug":"reactor-molten-lead-plutonium-fuel-america","status":"publish","type":"post","link":"https:\/\/www.autonocion.com\/us\/reactor-molten-lead-plutonium-fuel-america\/","title":{"rendered":"A 155-ton reactor vessel near Bologna runs on molten lead with electric heaters standing in for uranium, and the French firm that built it just told US regulators it wants to make plutonium fuel in America, where the last plant that tried is a half-built shell"},"content":{"rendered":"

Dress rehearsals are supposed to be the boring part. You run the whole show with nothing real at stake, you find out what leaks, and nobody gets hurt. Newcleo has spent 2026 doing exactly that with a 155-ton reactor vessel in the hills near Bologna, where electric heaters stand in for uranium and molten lead does everything the real coolant would do. But the French company has now filed the paperwork that points at opening night. On August 6, it handed the US Nuclear Regulatory Commission a plan for licensing a factory<\/a> that would turn recycled plutonium into reactor fuel on American soil.<\/p>\n

And if that idea sounds vaguely familiar, it should. America already built most of a plutonium fuel plant once. It cost billions, took over a decade, and the government walked away from the half-finished building. More on that in a minute.<\/p>\n

The rehearsal reactor was only ever half the story<\/h2>\n

Quick recap for anyone who missed the earlier chapters. Newcleo is building PRECURSOR, a full-scale non-nuclear demonstrator<\/a> at Italy’s ENEA Brasimone Research Centre. The vessel weighs a little over 20 metric tons empty and passes 155 once the molten lead and internals go in, and it was lowered into place in late May. Electric heaters play the role of the fuel, and a Fincantieri turbine will make actual electricity from a reactor with zero uranium anywhere in the building.<\/p>\n

It is a clever way to de-risk the scary part of a lead-cooled fast reactor, which is the lead itself. Molten lead eats steel, which is why the Swedish company chasing the same coolant needs three different alloys<\/a> in one machine just to keep its pump impeller alive. Prove the metallurgy first, add atoms later.<\/p>\n

But a lead-cooled fast reactor without fuel is a very expensive kettle. Newcleo’s reactors are designed to run on MOX, a blend of uranium and plutonium recovered from spent fuel. The company describes itself as the leading Western private firm pursuing licenses to make that fuel for advanced reactors, which is a polite way of saying nobody is actually doing it yet. So it decided to build that part of the supply chain itself, and this month it told American regulators how.<\/p>\n

Two filings in five weeks, and the second is the bigger ask<\/h2>\n

In July, Newcleo submitted a Regulatory Engagement Plan to the NRC for its commercial reactor, the 200-megawatt LFR-AS-200. On August 6 came the second one, this time for a US facility that would manufacture MOX fuel from recovered or surplus nuclear materials, according to World Nuclear News<\/a>. The company had opened pre-application talks with the NRC back in February, so this is the paperwork catching up with the conversations.<\/p>\n

A Regulatory Engagement Plan is not a license application. It is the document before the document, laying out which technical topics the company expects to hash out with NRC staff, what it plans to submit, and roughly when. The point is to surface the hard questions early, before anyone commits to a formal application that takes years to review.<\/p>\n

“This submission to the NRC is a concrete step to advance our MOX fuel facility in the U.S., building on the work of over 100 engineers with decades of industrial experience,” said Stefano Buono, Newcleo’s CEO, in the company’s announcement. The company has not announced where the American plant would go.<\/p>\n

The US filing leans on homework already done in Europe. In July, France’s nuclear safety authority ASNR judged the safety program for Newcleo’s planned French MOX plant satisfactory, and the company runs a testing center in Chusclan called FASTER, where prototypes of the fuel manufacturing line are already installed and running in a non-nuclear environment. Same philosophy as the Italian rig: rehearse everything, then go nuclear.<\/p>\n

America has been down the MOX road before, and it did not end well<\/h2>\n

Here is where the story gets uncomfortable for anyone with a long memory and a South Carolina zip code. Under a 2000 agreement, the US and Russia each committed to disposing of surplus weapons-grade plutonium, 68 metric tons between them. America’s answer was the Mixed Oxide Fuel Fabrication Facility at the Savannah River Site: take the warhead plutonium, blend it into reactor fuel, burn it in power plants.<\/p>\n

Construction started in 2007 with a 2016 start-up in mind and an original estimate of $4.9 billion. It did not go to plan. By 2018 the National Nuclear Security Administration terminated the contract<\/a>, and the agency later said finishing the plant would have taken until 2048 and cost $17 billion. The Post and Courier put the money actually spent at $5.4 billion on the half-built plant alone, roughly $8 billion counting the wider program. The government switched to diluting the plutonium and burying it, and the abandoned MOX building is being repurposed to make plutonium pits. Which are nuclear weapon cores. The factory meant to unmake warheads will now help make them.<\/p>\n

And there is one detail in the wreckage that deserves its own sentence: the failed American plant was modeled on France’s Melox facility. The next company proposing to make MOX on American soil is French. The design crossed the Atlantic once and sank; now the whole firm is coming over instead.<\/p>\n

\n
\n
ACTIVE<\/div>\n
Aug 6, 2026<\/div>\n
MOX plan filed<\/div>\n
Newcleo’s second Regulatory Engagement Plan with the NRC in five weeks, this one for the US fuel plant.<\/div>\n<\/div>\n
\n
The rehearsal<\/div>\n
155 tons<\/div>\n
Full weight of the PRECURSOR vessel in Italy once its molten lead goes in. No uranium involved.<\/div>\n<\/div>\n
\n
The precedent<\/div>\n
2048<\/div>\n
When NNSA said the abandoned Savannah River MOX plant would have been finished, at a cost of $17 billion.<\/div>\n<\/div>\n
\n
Sept 17, 2026<\/div>\n
Nasdaq vote<\/div>\n
NewHold shareholders decide on the merger that would list Newcleo under the ticker NWCL.<\/div>\n<\/div>\n<\/div>\n

The fuel would come out of the plutonium nobody wants<\/h2>\n

The material side of this got moving in May. The Department of Energy selected five companies for advanced negotiations under its Surplus Plutonium Utilization Program, which would hand designated surplus plutonium to industry and let it become advanced reactor fuel, under US security and safeguards rules.<\/p>\n

One of the five is Oklo, the NYSE-listed reactor startup, and its partner in the bid is Newcleo<\/a>. Oklo would lead the plutonium work while Newcleo brings the fuel experience and potential project capital, all of it still subject to definitive agreements. The two companies pitch it as disposition through use: the plutonium already exists, so fission it into electricity instead of guarding it forever.<\/p>\n

“Fuel supply constraints are a key throttle to advanced reactor development,” Oklo CEO Jacob DeWitte said in the announcement. He is not wrong. You can design the finest fast reactor on Earth and it will sit there doing nothing without fuel, and the enrichment supply chain for advanced reactors is years behind the reactor designs themselves. Leftover weapons plutonium is, in the coldest possible accounting, a shortcut.<\/p>\n

A Nasdaq ticker before the first watt<\/h2>\n

All of this is happening while Newcleo goes public. The company signed a definitive merger agreement with NewHold Investment Corp. III on May 27, and in early August the SEC declared the registration statement effective, per the joint announcement<\/a>. NewHold shareholders vote on September 17, and if it closes as planned in the second half of 2026, the combined company trades on Nasdaq as newcleo plc under the ticker NWCL.<\/p>\n

Buono has done the Nasdaq run before. He founded Newcleo after selling his previous company, nuclear medicine firm Advanced Accelerator Applications, to Novartis for $3.9 billion. This one has raised about $780 million in private funding and employs more than 900 people across Europe and the US, per the company. Between Oklo on the NYSE and Newcleo headed for Nasdaq, both halves of the plutonium partnership would be publicly traded before a single gram of that surplus material becomes fuel.<\/p>\n

So where does this actually stand? A Regulatory Engagement Plan is a roadmap, not a permit, and the formal license application it leads to typically takes years of NRC review. The American plant has no announced site. The Italian demonstrator is still scheduled to finish installation this year, and it will stay proudly uranium-free the whole time, because that was always the point. What changed this month is smaller and stranger than a groundbreaking: the company that got famous for practicing nuclear power without the nuclear part has now told American regulators, in writing, exactly how it wants to handle the real thing. The last people who tried left a $5.4 billion shell in South Carolina. Newcleo gets to decide how that story ends the second time.<\/p>\n","protected":false},"excerpt":{"rendered":"

Dress rehearsals are supposed to be the boring part. You run the whole show with nothing real at stake, you … <\/p>\n

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