The chairman of the Nuclear Regulatory Commission on Wednesday denied sweeping allegations by fellow commissioners that he bullied and abused agency staffers and withheld information.

During a dramatic and often tense exchange, the NRC’s four commissioners — two Democrats and two Republicans — told a House committee that they had doubts about the leadership of Chairman Gregory B. Jaczko and believed he fostered a hostile and often abusive management style.

But Jaczko, appointed by President Obama in 2009, defended his tenure by frequently telling lawmakers that “I am very passionate about safety.”

The hearing came amid an investigation by the House Oversight and Government Reform Committee that aides said began in the spring when agency staffers told the panel, which has oversight of government operations, of their concerns.

In his testimony, commissioner William D. Magwood, a Democratic appointee, said Jaczko regularly grew impatient and unhappy at meetings with staffers.

During one encounter, Jaczko “became increasingly irrational, and everyone in the meeting became very uncomfortable,” said Magwood, adding that staffers told him that Jaczko “sort of snapped.”

“It was like ‘The Exorcist,’ ” Magwood said staffers told him. He did not elaborate and wasn’t asked during the hearing to be more specific.

Magwood said he was especially concerned about heated exchanges he said occurred between Jaczko and three female staffers that left the women in tears. He didn’t elaborate and told lawmakers that none of the women is willing to talk publicly.

Speaking with reporters after the hearing, Magwood said that he learned of the women’s concerns in recent weeks and that at least one had filed a formal complaint with the NRC’s inspector general.

“My primary motivation in being here today is really to speak on behalf of the NRC staff, who I think have very high expectations of their commission,” Magwood told reporters. “And I don’t think we’ve entirely lived up to that.”

A ‘challenging’ year

In his testimony, Jaczko said the NRC has had an “exceptionally challenging” year as the agency responded to the Japanese tsunami and meltdown of the Fukushima nuclear plant. He said commissioners have held dozens of public meetings, and reviewed thousands of enforcement actions, license applications and other policy matters.

“This is the first time I’ve heard many of these accusations,” Jaczko said, adding later that “if there’s ever been a time that I’ve made someone feel uncomfortable, I certainly want to know so I can take whatever actions to remedy that.”

Seated at the center of a witness table with two commissioners on either side, Jaczko stared down at papers stacked in front of him as fellow commissioners listed their complaints against him.

Commissioner Kristine L. Svinicki, a Republican appointee, told lawmakers that most of the disagreements stemmed from interpretations of the chairman’s legal authority. An inspector general report published in the summer faulted Jaczko for withholding some information from the commissioners about the agency’s decision to stop a safety review of a proposed nuclear waste site at Nevada’s Yucca Mountain — a project opposed by the Obama administration and Jaczko’s former boss, Senate Majority Leader Harry M. Reid (D-Nev.).

Svinicki said that the commissioners had hoped to settle their disagreements privately but that events in recent months “pushed the commission beyond its tolerance for current circumstances.”

She cited an October retreat with senior agency officials, during which Jaczko expressed contempt for the commission and instructed the staffers to “advance his agenda and that this must come at the price of having their own, independent assessments and recommendations.”

Svinicki said the agency’s executive director described the meeting to her later by saying, “We were pretty much instructed to leave our brains at home.”

William C. Ostendorff, a Republican appointee, said the disputes were “about behavior that, if exhibited by one of the NRC’s regulated licensees, would be subject to investigation and potential enforcement action for a chilled work environment.”

George Apostolakis, the panel’s third Democratic member, said he agreed with his colleagues’ concerns and angrily denied that they were politically motivated.

After the hearing, Magwood agreed: “We’re a very apolitical group. We don’t talk about Republicans and Democrats; we just talk about nuclear safety and the issues at hand.”

Relentless questioning

Under relentless questioning by Republican lawmakers, Jaczko denied the accusations.

“I’ve listened very carefully to the concerns of my colleagues, and I’m certainly very interested in continuing a dialogue with them to better understand how we are not communicating effectively,” Jaczko said.

“That doesn’t seem like any sort of repentance,” Rep. Jason Chaffetz (R-Utah) told him.

“We’ve got people who are suffering under this gentleman right here,” said Chaffetz, pointing at Jaczko and raising his voice as he continued. “He is not living up to the duties. I don’t believe you. I think the safety and security of this nation is too important. I think you should resign.”

But Jaczko insisted: “I believe that many of these instances that they’re referring to are misconstrued,” he said, referring to his colleagues. He said he had no plans to resign.

The commissioners sat stone-faced as he replied.

Committee Chairman Darrell Issa (R-Calif.) said he would reserve judgment on Jaczko’s fate until commissioners had a chance to resolve their differences. He also urged the White House to keep close watch over the agency.

White House officials declined to comment Wednesday, noting that Jaczko had apologized to White House Chief of Staff William Daley about the agency’s internal issues becoming so public. Commissioners had written to Daley about their concerns.

But Magwood told reporters that Jaczko had yet to apologize directly to any of the commissioners.

“Rather than apologize to me, I think it’d be better if he apologized to some of the staff that he’s mistreated,” he said.