Head of US Agency Overseeing Nuclear Weapons Stockpile Resigns

Under Secretary for Nuclear Security of the U.S. Department of Energy and Administrator of the National Nuclear Security Administration Lisa Gordon-Hagerty tours the Ohio-class ballistic missile submarine USS Alabama in Bangor, Washington, on Oct. 10, 2018. (Amanda R. Gray/U.S. Navy/Handout via Reuters)

WASHINGTON—The head of the agency that oversees the U.S. stockpile of nuclear weapons has resigned, the U.S. Energy Department's National Nuclear Security Administration said on Friday, without providing a reason.

Lisa Gordon-Hagerty resigned as administrator of the NNSA, a semi-autonomous branch of the department.

William Bookless is now serving as NNSA's acting administrator, it said in a statement. He had been serving as NNSA's principal deputy administrator for the last year-and-a-half.

Gordon-Hagerty became the first woman to serve as administrator when she took up her post in early 2018.

NNSA oversees the development and maintenance of nuclear weapons, but not the delivery systems, which are managed by the Department of Defense.

DefenseNews was first to report Gordon-Hagerty's resignation.

The resignation drew criticism from Senator James Inhofe (R-Okla.), Republican chairman of the Armed Services Committee who praised Gordon-Hagerty and harshly criticized Secretary of Energy Dan Brouillette.

Inhofe alleged in a statement that "the Secretary of Energy effectively demanded her resignation."

Brouillette's office did not immediately respond to Reuters' request for comment.

Gordon-Hagerty had proposed a record budget of nearly $20 billion for fiscal year 2021 to help pay for modernization of the nuclear weapons stockpile, which is expected to cost more than $1.2 trillion over 30 years.

Brouillette had backed a budget of $17.5 billion proposed by the Office of Management and Budget, a White House office. President Donald Trump later sided with Gordon-Hagerty for a budget of nearly $20 billion.

By Timothy Gardner. Additional reporting by Patricia Zengerle.