The U.S. National Nuclear Security Administration (NNSA) has placed 1,400 of its employees on leave due to the government shutdown, which has lasted more than 20 days, according to Federal News Network.

Energy Secretary Chris Wright explained that the agency sent federal employees on leave because funding for salaries has been exhausted.

Approximately 400 NNSA employees will continue to work without pay to ensure the security of the nuclear arsenal and maintain minimum safety standards.

Wright noted that “this has never happened before.” “NNSA, our core organization, has existed for 25 years. We have never placed employees on leave. This should not have happened. However, this was the maximum we could do with federal employee funding,” he said during a visit to the National Nuclear Security Center in Las Vegas, Nevada, on Monday, October 20.

The Department of Energy confirmed that about 400 NNSA employees will remain on duty “to protect property and human life.” In particular, the agency’s secure transport office, responsible for the movement of nuclear materials within the U.S., is funded through October 27.

Meanwhile, Wright said the Department of Energy, in collaboration with the White House Office of Management and Budget, is working to continue payments to some NNSA contractors who service the agency’s nuclear facilities.

“We were able to carry out some financial maneuvers and extend contractor funding slightly,” Wright said.

He added that roughly 100,000 contractors work in national laboratories and the broader nuclear industry, and he expressed his desire to keep everyone employed.

“When these additional creative measures we identified run out, it will gradually affect various facilities, but tens of thousands of essential workers, their families, and our national security will be at risk,” the Energy Secretary said.

An NNSA employee, speaking on condition of anonymity, told the publication that leave notifications were received early Monday morning. Employees came to the office to set up automated email responses, clear out their workspaces, and prepare for an indefinite period of leave.

The employee said that these furloughs were another blow to staff morale in an already challenging year for federal service.

“Psychological pressure on federal employees is currently enormous,” the source said.

Earlier this year, NNSA had to urgently reinstate some employees after nuclear security personnel were unexpectedly dismissed during a government-wide purge initiated by the Department of Government Efficiency (DOGE).