The official in charge of building the proposed Yucca Mountain (search) nuclear waste dump in Nevada has submitted her resignation, the Energy Department announced Friday.

The departure of Margaret Chu (search) as director of the department's Office of Civilian Radioactive Waste Management comes at a time when the Yucca Mountain program has been delayed because of budget cuts and problems developing acceptable radiation safety standards.

The department said in a statement that Chu was leaving "due to personal circumstances" and that she plans to return to New Mexico. The resignation is effective Feb. 25, the statement said.

In Nevada, Bob Loux, head of the state office that has been fighting the proposed waste dump, said Chu's departure was not expected to change the Bush administration's determination to pursue the Yucca waste repository 90 miles northwest of Las Vegas.

"Clearly, the important decisions were being made elsewhere by other people," Loux said. The Yucca Mountain project remains a top priority at the White House and the department, Samuel Bodman (search), the new energy secretary, told a congressional hearing this week.