The squabble between four Nuclear Regulatory Commission members and NRC's Chairman, Gregory Jaczko, is even more public now that House and Senate committees have had a chance to air the dispute.

Jaczko, flanked at the witness table by his fellow commissioners, got grilled by the House Oversight and Government Reform Committee on Dec. 14, while his fellow commissioners got a generally sympathetic reaction from the lawmakers.

The following day, the tables were turned, as Senate Environment and Public Works Committee Chairman Barbara Boxer (D-Calif.) blasted the House hearing as "a witch hunt" and "an attempt to assassinate the character of a dedicated public servant"—namely Jaczko.

Jaczko, a Democrat and former aide to Senate Majority Leader Harry Reid (D-Nev.), was named NRC chairman in 2009, after serving as a commissioner for four years.

As the five commissioners return to work at their Rockville, Md., office, it's unclear how NRC's "chilled environment"—as Commissioner William Magwood described it—will affect them.

NRC has its hands full with serious matters. Perhaps at the top of the list is what regulatory, operational or oversight changes the commission will recommend for U.S. nuclear powerplants in the wake of the Fukushima Daichi disaster in Japan in March.

A NRC task force issued a series of recommendations in July,  but the commissioners have yet to decide which ones to endorse.

The four other commissioners—two Democrats and two Republicans—had taken the extremely unusual step of bringing their complaints publicly to the White House. In a letter to White House Chief of Staff William L. Daley, the four commissioners said they had "grave concerns" about Jaczko's "leadership and management practices" and contended that his actions "are causing serious damage" to the NRC.

The letter, though written in October, didn't become public until earlier this month, when House oversight panel Chairman Darrell Issa (R-Calif.) released it.

According to a Bloomberg story, Daley wrote to Issa saying that "while there are tensions and disagreements among the commissioners, these management differences have not impaired the commission's ability to fulfill its mission." 

In Jaczko's appearance before Issa's committee, he said he had no plans to resign. Under tough questioning by Issa's panel, Jaczko also denied contentions that he bullied NRC staff or withheld information from the other commissioners.

The dispute appears to be partly about Jaczko's temperament and partly about how he and the four others see the role of the chairman.

A 1980 NRC reorganization plan, put in place  after the 1979 Three Mile Island nuclear accident, strengthened the role of the NRC chairman, particularly during emergency situations, but it didn't turn the panel into a federal agency with a single, CEO-type boss.