When this reactor at Palo Verde Nuclear Generating Station is operating, no one, let alone a group of reporters, is allowed into this viewing area overlooking its core.
But on this day, when Unit 2?s reactor is having its fuel rods replaced, plant officials are using the opportunity to show how Palo Verde is different from the Japanese nuclear power plant that was leaking radiation after a devastating earthquake and tsunami.
The differences start, they say, with the containment walls towering above the core. Much thicker than those in the Fukushima Dai-ichi plant, the steel-reinforced concrete walls can withstand the impact of a jumbo jet or a 300 mph tornado.
The interior of the containment dome is 10 times more spacious than the containment buildings in Japan, meaning they would be better able to absorb energy during an emergency, plant officials say.
While the general public isn’t allowed this far inside the plant, Bob Bement, senior vice president of site operations, said Arizonans should understand that Palo Verde was engineered to maximize safety.
“It is important that the public learn about nuclear power,” he said. “Nuclear power, I believe, is part of our future.”
Palo Verde, which Arizona Public Service runs on behalf of several power companies, is the largest nuclear generating facility in the U.S. and supplies electricity to about 4 million customers in Arizona, California, New Mexico and Texas.
While concerns about Japan weren’t the only reason for the tour, events there are informing how Palo Verde’s operators prepare for emergencies.
In the plant’s response room, workers were going through responses to scenarios involving a power outage similar to the one that occurred at the Japanese plant.
During a power outage, Bement said, Palo Verde would have access to multiple sources of backup electricity, including emergency diesel generators and sets of batteries in each unit.
Palo Verde officials now are modifying procedures so the plant can operate on battery power for up to 72 hours if backup generators malfunction, Bement said.
“Now that we’ve seen a plant that lost off-site power and lost all of their backup AC power for an extended period of time, we will train on that,” he said.
Employees in the response room have also been monitoring the Japanese plant and are working with the U.S. Nuclear Regulatory Commission and the Institute of Nuclear Power Operations to improve ways the plant would share information with the public in an emergency, said Michael Powell, who is part of the plant’s crisis team.
Crossing a four-story-high walkway into the turbine building at Unit 1, the sweeping desert view illustrates the operators’ primary argument this plant is nothing like the one in Japan.
Palo Verde, which is about 50 miles west of downtown Phoenix, is located far from the ocean and away from areas prone to major earthquakes.
“This is an excellent location, and it was picked looking at how to design a plant and where to design it,” Bement said.
Although the plant isn’t close to a large body of water, it has enough water on-site – treated effluent – to cool its reactors for a year.
The plant’s biggest risks include an earthquake, the possibility of a 100-year flood and dust storms, but Dwayne Carnes, a communications consultant who was recently the assistant plant manager for Unit 2, said Palo Verde is prepared to withstand all of those.
“Our plant has inherent safety designs built in that are very robust,” he said.
And while the federal government has frozen efforts to build a central repository for spent nuclear fuel from plants across the nation, Palo Verde is in a good position to store its fuel, Carnes said. Tall storage cylinders with 28-inch-thick concrete walls house the waste, and the plant has enough land to keep increasing its storage capacity indefinitely, he said.
“However, our desire, like other nuclear utilities, is to ship it off for permanent storage in a depository where it will be monitored for a permanent solution,” Carnes said.
Palo Verde facts:
• Largest power producer of any kind in the U.S. since 1992.
• About 4 million people in Arizona, California, New Mexico and Texas receive its power.
• Operating since 1986.
• Located about 50 miles west of Phoenix.
• Arizona Public Service, which manages the plant on behalf of several utilities, owns 29.1 percent of Palo Verde.