U.S. firms developing a new generation of small nuclear power plants to help cut carbon emissions have a big problem: only one company sells the fuel they need, and it's Russian.

That's why the U.S. government is urgently looking to use some of its stockpile of weapons-grade uranium to help fuel the new advanced reactors and kick-start an industry it sees as crucial for countries to meet global net-zero emissions goals.

The energy crisis triggered by the war in Ukraine has renewed interest in nuclear power. Backers of smaller, next-generation reactors say they are more efficient, quicker to build, and could turbocharge the shift away from fossil fuels.

But without a reliable source of the high assay low enriched uranium (HALEU) the reactors need, developers worry they won't receive orders for their plants. And without orders, potential producers of the fuel are unlikely to get commercial supply chains up and running to replace the Russian uranium.

HALEU is enriched to levels of up to 20%, rather than around 5% for the uranium that powers most nuclear plants. But only TENEX, which is part of Russian state-owned nuclear energy company Rosatom, sells HALEU commercially at the moment.

While no Western countries have sanctioned Rosatom over Ukraine, mainly because of its importance to the global nuclear industry, U.S. power plant developers such as X-energy and TerraPower don't want to be dependent on a Russian supply chain.

Companies in the United States and Europe have plans to produce HALEU on a commercial scale but even in the most optimistic scenarios, they say it would take at least five years from the point they decide to proceed.

And this chicken and egg conundrum is complicating the smooth development of HALEU supply.

Last year, nuclear power stations in the United States imported about 14% of their uranium from Russia, along with 28% of their enrichment services, according to the U.S. Energy Information Administration.

Source: Reuters