Nuclear Agency Takes Blame for Ohio Reactor Damage

By J.R. Pegg

WASHINGTON, DC, October 10, 2002 (ENS) - The Nuclear Regulatory Commission has determined that it is partially to blame for the events that allowed a boric acid leak to eat almost entirely through the lid of the reactor pressure vessel head at the Davis-Besse nuclear power plant.

A report was published yesterday by the Nuclear Regulatory Commission (NRC) task force, charged with investigating the agency's handling of events at the plant in Oak Harbor, Ohio about 25 miles east of Toledo. It reveals that a web of misinformation, poor regulatory oversight and operator negligence allowed a preventable problem to become a serious safety hazard.

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Davis-Besse Nuclear Power Plant (Photo courtesy Ottawa County Emergency Management)
Of the three entities involved, the NRC, the plant operators and the nuclear industry, "no one connected the dots," said Ed Hackett, coauthor of the report. "When all the information was there, it should have been put together."

Last spring plant operators at Davis-Besse discovered that boric acid from a leaking nozzle had created a hole six inches deep and nearly five inches wide in the reactor lid. A smaller hole was found a few weeks later.

Borated water is used in pressurized water reactor plants as a reactivity control agent to aid in control of the nuclear reaction. The leak had also caused cracks in five of the 69 vessel head penetration (VHP) nozzles.

The plant's operators, FirstEnergy Nuclear Operating Company, reported the damage to the NRC, which sent inspectors to the plant on March 12, 2002. The leak and the subsequent damage, however, began as early as 1998.

The report cites three primary reasons why the degradation of the reactor pressure vessel head and the plant's VHP nozzle leakage occurred for so long without detection or action.

First, the agency, the plant's operators and the nuclear industry failed to adequately review, assess, and follow up on relevant operating experience.

Second, plant operators failed to assure that plant safety issues would receive appropriate attention.

Finally, the NRC failed to integrate known or available information into its assessments of the Davis-Besse plant's safety performance.

For example, the NRC and the nuclear industry were aware of cracks in VHP nozzles in a similar plant in France in the early 1990s and in the Oconee plant in South Carolina in the spring of 2001. Rather than focusing on preventing leaks, the agency simply requested that plant operators inform the agency of how they planned to monitor cracking in VHP nozzles.

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Besse reactor vessel head insulation showing the damage caused by boric acid (Photo courtesy NRC)
The NRC went along with industry's assessment that these cracks were not much of a safety risk and that corrosion could be easily spotted long before it caused a problem.

Evidence of boric acid deposits was identified at the Davis-Besse plant as early as 1998, but was not taken seriously by either the NRC or the plant's operators.

"There was a mindset among all three parties that boric acid deposits on the head weren't a big deal," Hackett said. "There was a belief that degradation of this type wasn't likely to happen, even though there had been a history of these things in U.S. and foreign plants showing that degradation could be quite rapid."

The task force concluded that a great deal of blame ultimately lies with FirstEnergy Nuclear Operating Company, which the report cites as repeatedly failing "to assure that plant safety issues would receive appropriate attention."

The Davis-Besse plant remains offline and its operators do not expect to restart the plant until next year. FirstEnergy has estimated the shutdown alone could cost it up to $400 million.

In total the task force offers more than 50 recommendations, including stronger and more vigorous oversight of the nation's nuclear power plants. These recommendations are currently under review by senior agency officials, who will face an even tougher task in finding money to fund any changes.

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Hole in the reactor lid at Davis-Besse (Photo courtesy Ohio Citizen Action)
Industry watchdogs remain concerned that similar problems at other reactors remain undiscovered. There are 69 pressurized water reactor plants in the United States; the other 34 U.S. nuclear plants are powered by boiling water reactors.

According to the Union of Concerned Scientists (UCS), nuclear power plant operators have also found cracks in 49 of the 59 nozzles on the reactor vessel head at North Anna Unit 2 near Richmond, Virginia.

The Washington, DC based nonprofit science policy group cites similar problems at plants in South Carolina, Missouri, Florida and Arkansas.

"The North Anna and Davis-Besse nuclear power plants operated for months or even years with reactor vessel head cracks leaking cooling water," said David Lochbaum, UCS nuclear safety engineer.

"Under NRC safety requirements, nuclear power plants are only permitted to operate for six hours with a cracked reactor vessel head. Owners risk catastrophic failure by operating any longer," Lochbaum warned.

The reactor vessel crack issue also raises concerns over the pending renewal of operating licenses for many aging nuclear power plants.

"These widespread leakage problems clearly demonstrate that the NRC is not requiring a thorough safety overhaul of aging nuclear power plants," said Lochbaum. "Tens of millions of dollars will be spent on these reactor vessel replacements. If the NRC doesn't enforce federal safety regulations like the six-hour rule, the price tag could include an avoidable accident."

FirstEnergy Corp. is being urged to investigate whether converting the Davis-Besse nuclear plant to oil or coal would be feasible.

Four members of Congress from northern Ohio have signed a letter to the company making the request, together with the consumer group Ohio Citizen Action, according to a report in the "Cleveland Plain Dealer" Wednesday. They are Representatives Dennis Kucinich and Stephanie Tubbs Jones of Cleveland, Sherrod Brown of Lorain, and Marcy Kaptur of Toledo, all Democrats.

FirstEnergy spokesman Ralph DiNicola told the newspaper the utility is focused on repairing Davis-Besse and restarting it as a nuclear power plant early next year.