North Anna’s nuclear containment domes
How safe are Virginia’s nuclear power plants from terrorists, hackers and natural disasters? Let’s put it this way: Dominion worries about such threats 24/7 so you don’t have to.
In addition to interfering in U.S. elections, Vladimir Putin’s busy cyber-servants have been probing information technology weaknesses in U.S. industry and infrastructure. Sophisticated cyber-attacks have been ongoing since at least March 2016. Perhaps most alarming, the Department of Homeland Security asserted last week, Russian hackers gained access to critical control systems at unidentified nuclear power plants.
“We now have evidence they’re sitting on the machines, connected to industrial control infrastructure, that allow them to effectively turn the power off or effect sabotage, the New York Times quoted Eric Chien, a security technology director at digital-security firm Symantec, as saying. “They have the ability to shut the power off. All that’s missing is some missing political motivation.”
Journalist Ted Koppel highlighted the vulnerability of the U.S. electric grid to attack in his 2016 book, “Lights Out: Cyberattack, a Nation Unprepared, Surviving the Aftermath.” Novelists have imagined the horrifying societal collapse following the collapse of the electric grid. As for nuclear plants, the potential for radioactive contamination makes the threat even more terrifying. Fear-inducing scenarios involve terrorist takeovers, the theft of spent radioactive fuel, and jetliners slamming 9/11 style into nuclear reactors.
The issue of security was top of mind for me when I toured Dominion Energy Virginia’s North Anna Power Station last month. I had the opportunity to pose the kind of questions that members of the public might ask.
I’m not qualified to render judgment on the effectiveness of Dominion’s security efforts, but I can say one thing: Security at the nuclear facility is something the company thinks about around the clock. Utility officials have spent enormous time and effort anticipating and preparing for any scenario you can imagine. Earthquake? Check. Hurricane? Check. Cyber-attack? Check. Armed terrorist attack? Check. Hijacked airplane flying into the nuclear containment dome? Check.
Based on what I learned, I’m not worried about natural disasters or terrorist attacks. The threat of cyber-sabotage continues to unsettle me, but the danger is to the transmission and distribution grid, not to nuclear power plants. Dominion officials assured me — and for a simple reason that I shall explain in due course, I believe them — that their nuclear power plant controls are not vulnerable to a cyber-threat.
If there had never been a Chernobyl or Fukushima, I might not even be asking these questions. As it is, those calamities did occur. We learned that, as thorough as they try to be, nuclear engineers don’t foresee every conceivable contingency. With nation states from Russia and China to Iran and North Korea seeking to penetrate and compromise our infrastructure, we need to keep up our guard. At the same time, we should avoid creating unnecessary alarm. So far, I’ve seen nothing that makes me lose any sleep.
Earthquakes, hurricanes, and aircraft strikes
On August 23 at 1:51:04 p.m., the control room of the North Anna Power Station began to shake, as if it were sitting on a giant vibrating phone, recalls Lee Baron, who worked in the control room then and now runs the company’s simulation center. Lights on the control board began blinking. Alarms emitted shrill beeping noises. Tiles fell from the ceiling. Outside the facility, some electric transformers cracked.
The earthquake, the worst trembler to shake the East Coast in at least a century, exceeded what the power station had been designed for, says Baron, but the facility “shrugged it off.” Following Electric Power Research Institute guidelines, the operators powered down the plant without incident. After minor repairs and two months of intensive inspections, the nuclear station was up and running again.
Media attention focused on the fact that the North Anna station was located on an ancient geologic fault line. The fact that the epicenter of the earthquake was just a few miles away under the town of Mineral led many to conflate the two. But, the two fault lines were unrelated, says Richard Zuercher, manager-nuclear fleet communications for Dominion.
Indeed, as College of William & Mary geologist Chuck Bailey concluded in a 2012 review of maps, photos, and reports, the fault underlying the North Anna Power Station had last been active about 200 million years ago. On the other hand, as the Mineral earthquake demonstrated, the geologic plate upon which the East Coast rests was more active than previously supposed.
Unlike some earthquakes that have a highly localized impact that creates heavy damage, Zuercher says, the Mineral shaker, which registered 5.8 on the Richter scale, diffused its energy and caused light damage over a vast area. The quake was felt as far away as Atlanta and New Brunswick. Virginia does not face a California-like threat of a massive killer quake.
Hurricanes and tornadoes are another theoretical threat. The concern is that wind might pick up a cars or telephone poles and hurl them like projectiles. The nuclear reactors, a third of which are underground, are protected by massive containment domes made of compressed concrete lined by steel plate and reinforced by steel rebar.
The 4 1/2-feet-thick dome wall “is built to take a licking,” says B.E. Standley, the Dominion executive in charge of nuclear power plant safety. “It can survive anything short of an asteroid strike or zombie apocalypse.” Continue reading