Human errors shuts down Pilgrim nuclear power plant
Multiple failures of the control room staff at the Pilgrim Nuclear Power Station last spring sparked the power plant's first emergency shutdown in years, according to a report released yesterday by the Nuclear Regulatory Commission, which found that the problems were likely serious enough to warrant a rigorous yearlong review of the plant's safety procedures.
The commission said its preliminary conclusion is the violations were of ``low to moderate safety significance,'' a level of safety failure that occurs infrequently at the nation's 104 power plants. Last year, for example, the commission made nine such findings and only two others that were considered of greater safety concern.
``It's rare for us to take this kind of action,'' commission spokesman Neil Sheehan said. ``It's a job of tremendous responsibility to be in the control room. We expect them to perform at the very highest levels. If there's a failure to do that, we expect the company to rectify that as soon as possible.''
The abrupt shutdown in May occurred as plant operators began restarting the reactor after a routine monthlong stoppage for maintenance and refueling.
``The inspection team determined that multiple factors contributed to this performance deficiency, including inadequate enforcement of operating standards, failure to follow procedures, and ineffective operator training,'' according to the report.
The report blames Entergy Corp., the Louisiana-based company that has run the 39-year-old plant since 1999 and is seeking to renew its operating license, which expires next year.
``Entergy did not adequately enforce human error prevention techniques, such as procedural adherence, holding prejob briefs, self- and peer-checking, and proper documentation of activities during a reactor start-up,'' according to the report.
Entergy officials said they are reviewing the report and have yet to decide whether to appeal the findings before they take effect in three months. If the findings are not overturned, the plant will have to submit to additional inspections, training, and new safety procedures.
``Pilgrim remains committed to the safe, reliable operation of the plant, and we'll use these lessons learned from this event to drive improved performance,'' said Carol Wightman, a Pilgrim spokeswoman, who noted that the company has already retrained staff and revised safety procedures.
She would not comment on whether any staff have been fired or removed from the control room as a result of the incident.
She could not recall the last time Pilgrim had such an automatic shutdown, which nuclear officials call a ``scramming'' incident, but she said, ``It's been years.''
NRC officials said nuclear power plants in the United States experience on average about one scram every two years.
Sheehan said the report found that the plant's control room operators failed to follow the right procedures as they began manipulating the control rods that block the nuclear reaction, to restart the reactor on May 10.
This allowed the fuel rods, which contain enriched uranium, to boil water in the reactor, turning a turbine that generates electricity.
But the plant went into emergency shutdown mode after the chain reaction in the nuclear core generated higher than expected power.
Sheehan said it was unlikely that the findings would have an effect on whether the plant's license is renewed next year.
``This is a day-to-day operational thing,'' he said. ``We look at potential environmental impacts, aging safety management systems, and longer-term issues, rather than looking at a singular issue.''
Critics of nuclear power said federal regulators should view the safety failures as further evidence that the nation is relying on a potentially dangerous energy source.
Representative Edward J. Markey, a longtime critic of the nuclear industry, said the incident in Plymouth reflects a pattern of problems at nuclear plants around the world.
His office previously told the Globe that four control room operators had been suspended at the plant.
``The recent incidents at nuclear plants from Massachusetts to Virginia to Japan have shown that human error and hubris, or the unexpected power of nature, require constant vigilance and updated safety measures to protect Bay State residents and anyone else who lives near a nuclear facility across America,'' he said in a statement.
Mary Lampert, director of Pilgrim Watch, a Duxbury group that opposes the plant's relicensing, said future human errors are her main concern.
``Human error is what caused Three Mile Island and the accident in Chernobyl, and human error contributed to the explosions in Fukushima,'' she said, referring to the reactor failures in Japan after the tsunami in March.
``The point is that human error is something that happens, and the best one can do to guard against it is to have rigorous training,'' Lampert said. ``It seems clear that the operators were not properly trained, and that's a serious issue.''