(Adds details on probes, Ross quote)
WASHINGTON, July 18 (Reuters) - U.S. Commerce Secretary Wilbur Ross said on Wednesday that he has launched a new national security investigation into uranium imports that could lead to tariffs or quotas to limit them.
The "Section 232" probe was prompted by a petition filed by two U.S. uranium mining companies, Ur-Energy Inc and Energy Fuels Inc, complaining that subsidized foreign competitors have caused them to cut capacity and lay off workers.
Ross said the probe would canvass the entire U.S. uranium sector from mining through enrichment and defense and industrial consumption.
Uranium is used in the U.S. nuclear arsenal and powers the Navy's nuclear aircraft carriers and submarines, along with 99 U.S. commercial nuclear reactors that produce 20 percent of the electricity consumed in the United States.
Ross added that the U.S. production of uranium has fallen to 5 percent of U.S. consumption needs from 49 percent in 1987.
"The Department of Commerce’s Bureau of Industry and Security will conduct a thorough, fair, and transparent review to determine whether uranium imports threaten to impair national security," Ross said.
The new probe is the fourth launched by the Trump administration under Section 232 of the Trade Expansion Act of 1962, previously a seldom-invoked Cold War-era law.
Probes on steel and aluminum imports have led to tariffs and quotas on the metals, prompting retaliation from trading partners including Canada, Mexico and the European Union. The Commerce Department is also conducting a "Section 232" probe into automotive imports that could lead to a significant hike in U.S. tariffs for the sector. (Reporting by David Lawder Editing by Chizu Nomiyama and Jonathan Oatis)