US reliance on Russia’s nuclear fuel poses a critical threat to national security and climate goals, said a senior Biden administration official, who urged Congress to provide funds to rebuild its domestic supply chain and restrict imports from the country.

Kathryn Huff, assistant secretary for nuclear energy, told the Financial Times (subscription needed) it was “gravely concerning” that about 20% of fuel used by the US nuclear reactor fleet is supplied through enrichment contracts with Russian suppliers.

Russia controls almost 50% of global enrichment capacity and had worked successfully to undermine the US nuclear supply chain over many years by dumping cheap enriched uranium products on world markets, she said.