Yankee rapped for 2006 radioactivity incident (Burlington Free Press)

By Sam Hemingway

The Nuclear Regulatory Commission lowered its safety rating for the Vermont Yankee nuclear power plant last year after the facility mistakenly sent a piece of machinery with abnormally high radiation readings to a Pennsylvania plant.

According to documents on file with the NRC, the equipment -- packaged inside a large container and shipped by truck -- had a reading of 820 millirems per hour when it arrived at the Susquehanna nuclear power plant near Berwick, Pa., on Aug. 31, 2006.

The reading was well above the allowable 200 millirems-per-hour limit, said Neil Sheehan, an NRC spokesman. A millirem is a measure of exposure to radiation; an acceptable exposure for a nuclear plant worker is 5,000 millirems per year.

Sheehan said the incident caused the Vernon reactor to lose its place among plants with the NRC's highest safety rating. The plant just regained that status last month, he said.

"It was clearly over the limit," Sheehan said of the radiation readings. "It was very concerning." He said no one was exposed to the high radiation levels because the "hot spots" inside the container were on its bottom, which lay on the truck's trailer bed.

Vermont Yankee's safety record has come under increasing scrutiny since the collapse of a cooling tower structure in August ripped a gaping hole in the side of the tower building and spilled thousands of gallons of water. Three days later, a malfunctioning turbine valve forced a temporary shutdown of the plant.

Last week, the Douglas administration announced it was joining the state's congressional delegation in calling for an independent safety assessment of Vermont Yankee, something done only once in the history of the NRC.

Dave O'Brien, commissioner of the state's Public Service Department, said the policy shift was designed in part to address growing concern among Vermonters about safety at the plant. Entergy is seeking to relicense the 35-year-old plant so it can be run for another 20 years.

Friendly fire

The Vernon plant also came under fire last week from an unlikely source -- union workers at the Pilgrim nuclear power plant in Plymouth, Mass.

Pilgrim and Vermont Yankee are among six plants owned by Entergy Nuclear, which is considering a plan to have the six spun off into a subsidiary company tentatively called SpinCo.

Union leaders at Pilgrim said they don't want that to happen if Vermont Yankee is in the mix.

"We at Pilgrim have worked long and hard to get a good safety record here," said David Leonardi, a Pilgrim senior operations instructor and vice president of Local 369, Utility Workers Union of America. "We're concerned that this fleet mentality will erode our safety record and drag down our performance."

The Pilgrim plant has NRC's top rating, as do 79 of the other 103 reactors around the country. Leonardi said Pilgrim also has earned the highest rating from the nuclear industry's Institute of Nuclear Power Operations.

He said he did not know what rating Vermont Yankee had received from the industry group. "I'm confident it's not the same as ours," Leonardi said.

David McElwee, an Entergy spokesman, said Vermont Yankee would not disclose the rating it was given by the industry group, which does not make its ratings public.

"That is something we absolutely do not talk about," McElwee said. "That would diminish the purpose of that kind of evaluation."

Leonardi said his union's concerns about Vermont Yankee were based primarily on the Vernon plant's cooling tower collapse in August and the subsequent problems with the turbine stop valve. He said he was unaware of the Susquehanna incident until informed about it by a reporter last week.

According to the NRC documents, the item sent by Vermont Yankee to the Susquehanna plant was a control rod crusher. Control rods are devices that lie between fuel rods in nuclear reactors and are used to stop the nuclear reaction by absorbing neutrons.

"Upon close examination, several small highly radioactive pieces of debris were identified," a portion of a Nov. 7, 2006, NRC report about the incident said. "It was fortuitous and not the result of design or package preparation that the material was deposited in such manner that effectively limited the potential for any public exposure."

In a follow-up report issued Aug. 21, 2007, the NRC said an analysis of the case had found that mistakes in packaging and testing at Vernon before shipment of the control rod crusher were to blame for the incident.

"Entergy identified the following two primary root causes: inadequate procedures for preparing the equipment for shipment ... and an insufficient questioning attitude of personnel involved in shipment preparation activities," the report said.

The report also found that the instruments Vermont Yankee used to test the shipment for radioactivity before shipment were "too large to access the small recesses in the equipment and detect the discrete radioactive particle contamination."

Larry Smith, an Entergy spokesman, said last week that Vermont Yankee had learned its lesson from the Susquehanna incident.

"We've dealt with it," he said. "We took corrective action immediately to ensure it doesn't happen again."