The Senate is under a strict deadline to confirm the head of the nation's top nuclear watchdog or risk closing the agency for lack of members.

Sen. John Barrasso, R-Wyo., chairman of the Environment and Public Works Committee, raised the concern Thursday in advancing the nomination of Kristine Svinicki, President Trump's pick to head the Nuclear Regulatory Commission, by voice vote to the Senate floor.

"Unless Ms. Svinicki is confirmed by June 30th, the Nuclear Regulatory Commission will lose its quorum," Barrasso said. "We must not let that happen."

Svinicki is the current chairwoman and has served on the commission for nearly a decade. Her term expires at the end of the month, and Trump has renominated her as chairwoman. But it is not clear if and when the Senate leadership will schedule votes on Svinicki and a roster of other energy-related nominees who need to be confirmed.

If she is not reappointed to the nuclear commission, it would leave the agency with only two members, forcing it to effectively shut down under the law. If that happens, it would be the second energy regulator to close under the Trump administration

The Federal Energy Regulatory Commission was forced to close in February for lack of a quorum. It was the first time that has happened in the energy watchdog's 40-year history.

The Senate also must vote on two new FERC commissioners who Barrasso's committee sent to the floor recently, with nominees to serve as deputy secretaries at the Energy and Interior departments.

Two other NRC commissioners are awaiting approval at the committee level, which weren't taken up Thursday.

"We must also act to confirm the other two nominees as expeditiously as possible to return the Nuclear Regulatory Commission to a full slate of five commissioners," Barrasso said.

"Until then, the Nuclear Regulatory Commission's collective ability to fulfill its mission of licensing and regulating the nation's civilian use of radioactive materials to protect public health, and to provide for safety and security, will be diminished," he said.