WASHINGTON • The chairman of the Nuclear Regulatory Commission blows up in abusive anger, intimidates staff members and withholds information from the rest of the commission, all four of his fellow commissioners testified to Congress on Wednesday.

The commissioners told a House of Representatives committee that they were able to do their jobs despite the chairman but that they worried about the future of the nuclear safety agency if the high state of tension persisted.

NRC Chairman Gregory Jaczko, who sat in the middle of a hearing table with the other commissioners on each side of him, said that their accusations were untrue and that he had no reason to apologize. However, he acknowledged that he had work to do to communicate better and regain their confidence.

"This is the first time I've heard many of these accusations," Jaczko said at a hearing of the House Committee on Oversight and Government Reform. "Certainly if there's ever been a time I've made someone uncomfortable, I always want to know so I can take any action necessary to remedy that."

The other commissioners were blunt.

Commissioner Kristine L. Svinicki said Jaczko's "continued outbursts of abusive rage" at subordinates had become more frequent.

"All members of the commission, including me, have been on the receiving end of this conduct," she said.

Commissioner William C. Ostendorff said Jaczko's behavior had 'significantly eroded the prized open and collaborative work environment of our nation's nuclear safety agency."

He and others said they hadn't been fully informed about the NRC staff's views and recommendations.

"Today it is routine for individual members of the staff to come to commissioners to alert us about issues they believe require commission attention, but that staff can't get through the chairman," Commissioner William D. Magwood IV said.

Magwood also said he had spoken with three women on the NRC staff who said they'd done nothing wrong but had been subjected to Jaczko's "raging verbal assault."

"I do not believe that fear, intimidation and humiliation are acceptable leadership tactics in any organization, least of all the Nuclear Regulatory Commission," Magwood said.

The four commissioners wrote a letter to White House Chief of Staff Bill Daley in October complaining about Jaczko.

Rep. Darrell Issa, R-Calif., the chairman of the House Oversight and Government Reform Committee, released the letter last Friday and called the commissioners and other NRC officials to Wednesday's hearing.

Daley said in a letter to the commission Tuesday that the "management differences" hadn't jeopardized the safety of nuclear plants. He said Jaczko agreed to keep the other commissioners better informed. Daley also said Jaczko proposed that the commissioners all meet with a "trusted third party to promote a better dialogue."

Bill Borchardt, the NRC's executive director for operations, a 28-year veteran of the agency, said Jaczko decided when the other commissioners got certain documents, a change in practice from past chairmen.

Testifying after the commissioners spoke, he said he'd been on the receiving end of Jaczko's temper. Asked whether he'd tolerate the same behavior by a subordinate, Borchardt said no.

Issa asked each commissioner whether NRC staff members had experienced "intimidation, hostile or offensive conduct" by Jaczko.

Each answered, "Yes."

"Ladies and gentlemen, that's the definition of harassment," Issa said.