by John Sullivan and Cameron Hickey, Special to ProPublica July 27, 2011, 2:04 p.m.
When he retired after 26 years as an investigator with the Nuclear Regulatory Commission's Office of the Inspector General, George Mulley thought his final report was one of his best.
Mulley had spent months looking into why a pipe carrying cooling water at the Byron nuclear plant in Illinois had rusted so badly that it burst. His report cited lapses by a parade of NRC inspectors over six years and systemic weaknesses in the way the NRC monitors corrosion.
But rather than accept Mulley's findings, the inspector general's office rewrote them. The revised report shifted much of the blame to the plant's owner, Exelon, instead of NRC procedures. And instead of designating it a public report and delivering it to Congress, as is the norm, the office put it off-limits. A reporter obtained it only after filing a Freedom of Information Act request.
Now, Mulley and one other former OIG employee have come forth with allegations that the inspector general's office buried the critical Byron report and dropped an investigation into whether the NRC is relying on outdated methods to predict damage from an aircraft crashing into a plant.
The inspector general's office, they assert, has shied away from challenging the NRC at exactly the wrong time, with many of the country's 104 nuclear power plants aging beyond their 40-year design life and with reactor meltdowns at Fukushima rewriting the definition of a catastrophic accident.
"We're in the nuclear power business. It's not a trivial business; it's public health and safety," said Mulley, who won the agency's top awards and reviewed nearly every major investigation the office conducted before he retired as the chief investigator three years ago.
In the office's history, Mulley has left a big mark.
For years, he documented how the NRC dropped the ball on the handling of nuclear fuel and security in nuclear plants. His reports on defective fire barriers led to congressional hearings and ultimately to a complete overhaul of the agency's fire protection regulations.
He retired in 2008 as a senior-level assistant for investigations but continued work as an OIG consultant for two more years. Before he retired, Bell and a deputy wrote that Mulley was "so thorough and knowledgeable of all aspects of investigations, that even NRC management recognizes the value added to having Mr. Mulley's expertise on all cases."
Mulley is not alone in his concerns about the inspector general's office. Another former employee told ProPublica that the office has become reluctant to probe anything that could become controversial or raise difficult questions for the NRC.
"They don't want to do anything," said the ex-employee, who left out of dissatisfaction with the direction of the office and asked not to be named to protect his current job. "Everything just seems to die."
The former employee told ProPublica that the OIG's office had dropped an inquiry into whether the NRC could accurately predict the damage to a plant from an airplane crash, and Mulley confirmed his account, saying the office received a tip in 2007 that the NRC was using an outdated method.
Because a wrong prediction could lead to insufficient protection for the plants, the inspector general's office opened an investigation, Mulley said. "We went to several experts who said that thing is antiquated, you can't use it," he said.
His team interviewed workers and NRC inspectors assigned to the Byron plant since the early 1990s. They concentrated heavily on the inspectors' actions in 2007, when Byron engineers began scrutinizing pipe sections, called risers, that were partly buried in concrete in a below-ground vault.
Plant engineers performed ultrasonic tests on the thickness of the risers. Originally, the pipe walls were three-eighths of an inch thick, but over the span of three tests, engineers stepped the acceptable thickness down to three-hundredths of an inch -- equivalent to seven sheets of paper.
Mulley's team found that the NRC's on-site inspectors had not checked the Byron engineers' work even though repeated drops in safety margin should have been a red flag. Corrosion in Byron's essential water system had been discussed in plant meetings, and because testing the risers required repeated use of a crane to gain access, inspectors should have suspected something.
"The NRC is supposed to -- if they're overseeing this thing -- take a look at it and say, 'Oh, wait a minute, what's going on?'" Mulley said. "But obviously, they didn't look at that one."
Mulley found that NRC's on-site inspectors had repeated opportunities to check the pipes over the years but had not done so. In interviews, the inspectors told Mulley's investigators that they had been busy with other work. Although inspectors had preformed a required number of equipment checks, Mulley's report found that their inability to set priorities was a weakness in the inspection program.
The NRC, it turns out, had received a warning about a similar pipe break at the Vendellos nuclear plant in Spain, Mulley's team discovered. Peter B. Lyons, then an NRC commissioner, had even mentioned the Vendellos break in a speech, saying the agency was on top of the problem. But the word was never sent to NRC inspectors in the field, Mulley found.
"I don't think anybody up there was purposely saying, 'Hey, this is not so important,'" Mulley said of the Vendellos information. "I think they knew it was important. I think they intended to. I don't think anybody followed up on it, and then it falls into the cracks."