Tensions at the Nuclear Regulatory Commission, the nation’s chief overseer of civilian nuclear materials, finally boiled over into public finger-pointing and accusations of malfeasance late Friday—creating what one lawmaker called “a regulatory meltdown.” It’s a messy conflict, but one thing is clear: the nuclear industry has many friends on the NRC.

On Friday, Representative Darrell Issa released a letter written in October by four of the commission’s five members. It accused the fifth member, Gregory Jaczko—who is also the NRC Chairman—of “causing serious damage” to the agency with “increasingly problematic and erratic behavior.” The commissioners feel Jaczko limited their role and bullied them in an emergency review of the nation’s nuclear facilities following the Fukushima meltdown in March.

The four commissioners’ complaints stem from when Jaczko invoked some emergency powers right after the Fukushima catastrophe. These powers transfer more authority to the chairman, in the name of streamlining NRC function when something crucial is happening. Jaczko created of a task force to study the Fukushima meltdown and issue recommendations about how to protect civilian nuclear facilities here from a similar fate, and the four commissioners claim not to have been notified of the new emergency powers and not to have been adequately consulted on the task force’s recommendations, which were released this summer.

But also on Friday, Representative Ed Markey of Massachusetts released a detailed report directly challenging those four commissioners. His report concludes that they “have attempted a coup on the Chairman” and have “caused a regulatory meltdown that has left America’s nuclear fleet and the general public at risk.”

Markey’s report paints a different picture than what the four commissioners claim—and reveals them to be primarily interested in protecting the nuclear industry.

His staff obtained thousands of pages of e-mails, correspondence, meeting minutes and other materials, and uncovered clear evidence that the four commissioners were largely kept in the loop about the new emergency mode. And in several e-mails, the commissioners pettily gripe amongst each other about Jaczko’s leadership; after one conference call with Jaczko, they e-mail back and forth with comments such as “what a bunch of shit,” “I detected a significant amount of ass-kissing” and “that was a bunch of Barbra Streisand.”

But this isn’t about bureaucratic backbiting. The Markey report demonstrates that at many different decision points the four commissioners were opposed not just to Jaczko’s leadership but what he was doing—namely, trying to toughen regulations on the nuclear industry. At several key points, the rebellious commissioners try to slow down or halt post-Fukushima disaster measures.

Key among Markey’s findings:

1. Four NRC commissioners attempted to delay and otherwise impede the creation of the NRC Near-Term Task Force on Fukushima.

2. Four NRC commissioners conspired, with each other and with senior NRC staff, to delay the release of and alter the NRC Near-Term Task Force report on Fukushima.

3. The other NRC Commissioners attempted to slow down or otherwise impede the adoption of the safety recommendations made by the NRC Near-Term Task Force on Fukushima.

4. NRC Chairman Greg Jaczko kept the other four NRC Commissioners fully informed regarding the Japanese emergency, despite claims to the contrary made by these commissioners.

5. A review of e-mails and other documents indicates high levels of suspicion and hostility directed at the chairman.

When President Obama was campaigning in 2008, he called the NRC “a moribund agency…captive of the industry that it regulates.” The Nation’s Christian Parenti has also detailed the influence the nuclear lobby has on the NRC. What’s happening now seems to be another symptom of that problem.

In the e-mails, the four commissioners mount an attempt “review” the Fukushima’s Task Force findings before they were released to the public. Jaczko is quoted second-hand as being concerned this review process “may create the impression the commission will sanitize the reports,” which appears to be exactly what was happening.

To give one example: as the Task Force report was being finalized, and the four commissioners had been unable to delay it, they had a senior NRC staff member attach a memo to the report. This memo basically tried to put the brakes on the reforms the Task Force was advocating: specifically, it said “before deciding on the path forward and the specific recommendations in the Task Force’s report, the Commission may wish to solicit external stakeholder input” and that there would be a benefit “to developing alignment on the objectives, approaches and schedules [with that of external stakeholders] for implementing safety improvements.”

To those not familiar with Washington speak, when regulators talk aligning objectives to those of “external stakeholders,” they mean: make sure the industry approves these regulations. Jaczko had this memo removed from the report before it was released.

Markey’s report takes pains to detail the times when the four commissioners voted against safety regulations, and where the only holdout was Jaczko. Some examples:

In June 2010, the commission voted 4-1, with Jaczko the lone “no” vote, to reduce limitations on the number of work hours for employees who perform quality control at nuclear facilities.

In December 2010, the commission voted 4-1, with Jaczko again the lone opposition vote, not to require specific NRC licenses for radioactive materials that could be used to create small nuclear devices, also known as “dirty bombs.”

In March 2011, the commission voted 4-1, with Jaczko again the lone opposition vote, to ignore a recommendation from the NRC’s own Advisory Committee on Reactor Safeguards about increased safety measures to prevent meltdowns in the event of fire or earthquake. This happened only four days after an earthquake struck the Fukushima Daiichi plant in Japan.

The four commissioners are now enjoying support from many Republicans on Capitol Hill, who not incidentally also oppose tougher regulation. Issa has been hitting the airwaves today in support of the four commissioners, and bashing Jaczko. Senator Lisa Murkowski, the top Republican on the Senate Energy Committee, basically called for Obama to remove Jaczko on Saturday—she said Jaczko’s alleged supposed actions are “a serious breach of the public’s trust” and that “such behavior is unacceptable at every level of government and a response from the president is long overdue.”

Democrats, meanwhile, are defending the chairman. “It is sad to see those who would place the interests of a single industry over the safety of the American people to wage a politically-motivated witch hunt against a man with a proven track record,” said Senate majority leader Harry Reid in a statement. (Jaczko used to work for Reid’s Senate office as a policy adviser).

All of this is a backdrop for what will surely be combative hearings on Capitol Hill this week. All five commissioners will testify before Issa’s House Committee on Government Oversight on Wednesday, and then before the Senate Environment and Public Works Committee on Thursday. I’ll be at both hearings and will continue to provide updates.