WASHINGTON — The chairman of the Nuclear Regulatory Commission (NRC) blows up in abusive anger, intimidates employees and withholds information from the rest of the commission, all four fellow commissioners testified to Congress on Wednesday.

The four commissioners — two Democrats and two Republicans — told a House committee they were able to do their jobs despite the chairman but worried about the future of the nuclear-safety agency if the high state of tension persisted.

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

"This is the first time I've heard many of these accusations," Jaczko, a Democrat, 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 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 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 Magwood said.

Magwood also said he'd 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."

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 panel's chairman, asked each commissioner whether NRC staff members had experienced "intimidation, hostile or offensive conduct" by Jaczko. Each answered, "Yes."