RENO, Nev. (AP) -- The U.S. Department of Energy revealed on Wednesday that it secretly shipped weapons-grade plutonium from South Carolina to a nuclear security site in Nevada months ago despite the state's protests.
The Justice Department notified a federal judge in Reno that the government trucked in the radioactive material to store at the site 70 miles (113 kilometers) north of Las Vegas before Nevada first asked a court to block the move in November.
Department lawyers said in a nine-page filing that the previously classified information about the shipment from South Carolina can be disclosed now because enough time has passed to protect national security. They didn't specify when the one-half metric ton of plutonium was transferred.
Nevada Gov. Steve Sisolak said he's "beyond outraged by this completely unacceptable deception." He announced at a hastily called news conference in Carson City late Wednesday the state is now seeking another court order to block any more shipments of plutonium as it pursues "any and all legal remedies," including contempt of court orders against the federal government.
The newly elected Democrat said he's exploring options for the plutonium that already has arrived and is working with Nevada's congressional delegation to fight back against the U.S. government's "reckless disregard" for the safety of Nevadans.
Democratic Sen. Jacky Rosen called the government's move "deceitful and unethical." Sen. Catherine Cortez Masto, also a Nevada Democrat, said she would demand department officials come to her office on Thursday to explain how they made the "reckless decision" in such "bad faith."
Democratic Rep. Dina Titus said the Trump administration has repeatedly tried to use Nevada as a dumping ground for nuclear waste. Trump revived a decades-old proposal to store the nation's nuclear waste at another site outside Las Vegas, Yucca Mountain, after the project was essentially halted under the Obama administration.
Justice Department lawyers said in new court filings Wednesday that no more shipments of weapons-grade plutonium are planned from South Carolina to Nevada. They said they believe Nevada's lawsuit aimed at blocking the shipments is now moot.
But lawyers for Nevada said late Wednesday that their bid for an emergency injunction is more critical than ever after the Energy Department misled them about the shipments. They say the government has created the "palpable suspicion" that more shipments are coming to Nevada.
Sisolak described the months-long negotiations with Energy Department officials over the plutonium leading up to the new disclosure as a "total sham."
"They lied to the state of Nevada, misled a federal court, and jeopardized the safety of Nevada's families and environment," he said.
U.S. District Judge Miranda Du in Reno already is considering the state's earlier request to block the Energy Department's plans — announced in August — to ship a full metric ton of plutonium to Nevada from South Carolina, where a federal judge previously ordered that the plutonium be removed from a Savannah River site by 2020.
Nevada argues the department has failed to adequately study the potential dangers of moving the material that still has the potential to be used to help develop nuclear weapons to an area that is subject to flash floods and earthquakes, and that the state's lands and groundwater may already be contaminated with radioactive materials.
In January, Du declined to immediately block the plutonium and indicated she wouldn't rule until February. "I hope the government doesn't ship plutonium pending a ruling by this court," she said at the time.
Nevada and the Justice Department filed their latest briefs Wednesday at the request of the judge, who questioned whether the case should go forward. Justice Department lawyers said any additional plutonium removed from South Carolina would not go to Nevada.
Meanwhile, the states of Nevada and South Carolina are continuing to argue over where any legal challenge should be heard. Each said in briefs filed in Reno last week that theirs is the proper venue.
Nevada's experts testified that the material likely would have to pass directly through Las Vegas on the way to the Nevada National Security Site. They fear an accident could permanently harm an area that is home to 2.2 million residents and hosts more than 40 million tourists a year.
The Energy Department's plan approved last August called for the full ton of material to be stored at the Nevada nuclear security site and the government's Pantex Plant in Texas, two facilities that already handle and process plutonium. The department says it would be sent by 2027 to the Los Alamos National Laboratory in New Mexico or another unnamed facility.
Associated Press writer Ryan Tarinelli contributed to this report from Carson City.