UPDATE 1-China reactors will yield weapons-grade plutonium -U.S. commander

(Adds comments from former U.S. State Department nonproliferation official)

WASHINGTON, April 21 (Reuters) - A new generation of nuclear power facilities that China is developing could produce large amounts of plutonium that could be used to make nuclear weapons, the head of the U.S. Strategic Command warned lawmakers this week.

China is developing fast breeder reactors and reprocessing facilities as it seeks to reduce dependence on coal, a top source of carbon emissions. But the plants also produce plutonium that could be used to make nuclear weapons. The first fast breeder reactor is projected to come on line in 2023.

“With a fast breeder reactor, you now have a very large source of weapons grade plutonium available to you, that will change the upper bounds of what China could choose to do if they wanted to, in terms of further expansion of their nuclear capabilities,” Navy Admiral Charles Richard, commander of the U.S. Strategic Command, told the Senate Armed Services Committee on Tuesday. STRATCOM oversees the U.S. nuclear weapons arsenal.

There is no evidence that China intends to divert its potential plutonium stockpile to weapons use, but concern has grown as Beijing is expected to at least double its number of nuclear warheads over the next decade from the low 200s.

China says its nuclear program is for peaceful purposes. The Chinese embassy in Washington did not immediately respond to a request for comment.

Last month a report here called "China's Civil Nuclear Sector: Plowshares to Swords", said China has started building a second plant to reprocess spent nuclear fuel that could be commissioned before 2030.

Richard said U.S. officials learned recently about how quickly China is moving to build its civilian nuclear program.

About a week ago “we became aware of that and started the process to understand the implications,” Richard said.

Christopher Ford, a former nonproliferation official at the State Department under former President Donald Trump, said U.S. officials may not be able to do much on the issue besides denounce it and “point out how destabilizing it is in the region ... and put pressure on China not to do this economically needless and strategically dangerous thing.”

Nuclear waste reprocessing has not been practiced for decades in the United States after former President Jimmy Carter halted it on proliferation concerns. (Reporting by Timothy Gardner; Editing by David Gregorio)