Virginia has four nuclear reactors, two each at Surry and North Anna. A recent study by the Richmond Times Dispatch reported:
In the past two years, Dominion Virginia Power’s four nuclear power reactors experienced 12 unplanned shutdowns.
Then, the Aug. 23 earthquake in Louisa County forced two more shutdowns at the North Anna Power Station.
“That’s too many trips for us,” said David A. Heacock, president and chief nuclear officer of Dominion Nuclear. “And we’re going to ensure it’s not going to continue.”
Unplanned shutdowns — also called “trips” or “scrams” — of the utility’s most important electric generating stations could potentially cause dangerous safety issues and lead to an increase in the cost of power.
The NRC put Dominion’s outages into perspective:
“An excessive number of unplanned scrams can indicate particular problems in maintenance or certain other areas,” said Joey Ledford, spokesman with the Nuclear Regulatory Commission in Atlanta. “That’s a signal that there are things that need to be looked at.”
The Times Dispatch reported that there were a variety of causes for the Surry and North Anna shutdowns:
Excluding the earthquake shutdowns, four of Dominion Virginia Power’s unplanned shutdowns since October 2009 were due to pipe leaks, two were due to lighting strikes, two to a tornado, one to a mechanical failure and three to human errors.
Dominion has more down time than the national average:
Nationally, nuclear reactors have been averaging less than one unplanned shutdown per unit annually, according to the NRC.
“North Anna and Surry were well above the industry average,” said David Lochbaum, a nuclear engineer with the Union of Concerned Scientists.
Dominion’s average capacity is also below the industry average:
Last year, three of Dominion Virginia Power’s nuclear units also performed below the national average using a measure called the “capacity factor,” which is the time a nuclear station operates compared with running 100 percent of the time.
In 2010, for instance, Dominion Virginia Power’s Surry 1 unit had a capacity factor of 87.65 percent, North Anna 1’s capacity factor was 84.31 percent, and North Anna 2’s was 79.3 percent.
Nationally, the average availability of nuclear units was 92.1 percent, according to the U.S. Energy Information Administration. Only Surry 2, at 98.76 percent, was above the national average.
Dominion’s response to capacity issues makes one wonder if they know what the word average means:
Company officials point out that the capacity factor is also affected by outages for refueling, as well as maintenance and upgrade work.
Seems as if all those issues affect all nuclear reactors, and are reflected in the average capacity number.
David Lochbaum of the Union of Concerned Scientists thinks that Dominion’s record may reflect underlying problems:
Three factors affect the safety of nuclear plants: events, something untoward happening at the plant; equipment; and people.
“It you have pre-existing weaknesses,” Lochbaum said, “and then you have an earthquake, those pre-existing weaknesses can line up to create the perfect storm that turns a bad day into a catastrophic day.”
Lockbaum thinks that the age of Dominion’s reactors may be a factor:
Equipment and human failures tend to cluster at the beginning and end of a plant’s life, he said.
Dominion Virginia Power’s plants came online between 1972 and 1980. Originally licensed for 40 years, those licenses have been extended for an additional 20 years.
Some Virgina residents agree:
“I think they’re unsafe,” said Erica Gray of Henrico County, with the Coalition Against Nukes. “I think most of them are old and they’re falling apart. I’m just scared that we’re going to end up with an incident here that could render parts of our state uninhabitable.”
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