Washington

The embattled head of a review board for the proposed Yucca Mountain nuclear-waste repository has resigned. His critics had charged that he was too closely tied to the nuclear industry.

Michael Corradini, a nuclear engineer at the University of Wisconsin at Madison, announced his resignation from the Department of Energy's Nuclear Waste Technical Review Board on 30 December. His public support for the Yucca Mountain Project and his pursuit of nuclear research had led project opponents, including all five members of Nevada's congressional delegation, to question his impartiality and call for his resignation.

The review board is set up as an independent body, and has been charged with evaluating the energy department's licence application for the Yucca project (see Nature 418, 262; 200210.1038/418262b ). It has long been considered an impartial judge of technical questions, says Judy Treichel, executive director of the Las Vegas-based Nevada Nuclear Waste Taskforce, which opposes the project.

Treichel claims that this record of impartiality was threatened in June 2002, when the Bush administration appointed Corradini as chair. Corradini has testified to Congress in support of the project. He also continued to receive funding from the energy department for his research on nuclear power — something other board members say they have stopped doing. The congressional delegation sent a letter to President George Bush on 25 February 2003 calling for Corradini's resignation. Faced with such local opposition, the nine other board members wrote to Corradini in May, asking him to go.

Corradini at first refused to step down, saying that he would not give in to “political pressure”. Nor did he back away from support of the project, co-authoring a newspaper article last October that stated that “Yucca Mountain is doable”.

“It was a bit like a judge making a statement about the verdict before the trial has begun,” says Norman Christensen, an ecologist at Duke University in North Carolina and a board member.

Corradini disputes that. “I don't think that me stating a fact makes me unacceptable, and I also don't think that makes me lack objectivity,” he says.

Nonetheless, he concedes that opposition to his appointment had made it difficult for the committee to function, and so offered his resignation.