When one of the earth’s great tectonic plates thrust under another off the east coast of Japan in March 2011, it generated a violent earthquake and set off a tsunami with waves that reached heights of 20 feet or more. This devastating combination left tens of thousands of people dead and set off a nuclear crisis when seawater flooded the site of the Fukushima Daiichi Nuclear Power Plant , cutting power and disabling backup safety equipment.
Crews were unable to keep the reactors cool, which led to fuel melting, hydrogen explosions and the release of radioactive material. More than nine months passed before authorities announced the reactors had been brought to a stable state of cold shutdown. Safety concerns also led to the shutdown of nearly all of Japan’s other nuclear plants.
The Fukushima event—the worst nuclear accident since Chernobyl in 1986—has cast a shadow over atomic energy and the industry's burgeoning hopes for a "nuclear renaissance." More than two years later, Japan has restarted only two of the nation's 54 reactors, and dangers persist at Fukushima as workers struggle to contain radioactive wastewater leaks. Germany and Switzerland have decided to phase out nuclear power, and many other nations are reassessing their nuclear ambitions. In June 2011, Italian voters rejected their country’s nuclear program in a referendum.
Yet for an increasingly energy-hungry world, nuclear remains a tantalizingly reliable, carbon-free power source, and an attractive way to diversify energy supplies and move away from sources including coal that contributes to climate change. "We need a renaissance of some technology that can take the place of coal," says Per Peterson, a professor of nuclear engineering at the University of California, Berkeley. Both coal and nuclear plants are costly to build but able to provide reliable power around the clock with relatively low fuel costs. "It's difficult to see how you could possibly displace coal if you don't include nuclear," Peterson says.
Globally, the future of nuclear lies increasingly in China and India. "The nuclear renaissance is currently underway but primarily outside the United States," says Dan Lipman, executive director of strategic supplier programs for the Nuclear Energy Institute, an industry group. Seven of the 66 plants now under construction worldwide are in India. And China linked its 17th nuclear reactor to the power grid in February.
The story is more mixed in the United States, though the country leads the world in nuclear electricity output. Until recently, 104 reactors in 31 states provided about 19 percent of the nation's electricity. The U.S. Energy Information Administration anticipates new reactors will add about 5.5 gigawatts—comparable to nearly three Hoover Dams—of nuclear capacity by 2025. This spring, construction of two new reactors began for the first time in 30 years.
But low natural gas prices have taken a bite out of revenues for plant owners. The fleet dropped to 102 reactors this spring due to plant closures, the most recent example being Wisconsin’s Kewaunee nuclear station, which saw its profits eaten away by the natural gas glut. The shutdown has fueled predictions that more closures may be on the way as older nuclear plants struggle to compete. Duke Energy dropped plans for two new reactors in North Carolina and officially retired its Crystal River reactor—offline for two years—in Florida after decades of operation, having opted for shutdown rather than repair. EIA forecasts see natural gas and renewables taking up larger slices of a growing U.S. energy pie, depending on prices and subsidies.
The 1979 nuclear accident at Three Mile Island in central Pennsylvania, like Fukushima, came at a similar time of nuclear growth. By the time of the Chernobyl disaster, though, that growth had begun to slow. It stagnated not only because of heightened safety concerns but also due to a drop in fossil fuel prices in combination with the long delays, ballooning budgets and high financing charges that were the hallmarks of new-plant construction in the 1980s and '90s. Then, as now, the economics of nuclear proved daunting.
Interest in nuclear eventually rekindled. From around 2005, Lipman says, a confluence of factors fired up construction. Economic growth boosted electricity demand, and historically volatile natural gas prices were on an upswing. The Energy Policy Act of 2005 provided loan guarantees and other incentives for new nuclear plants, and residential electricity demand in southeastern states—particularly Florida—"was growing like gangbusters," he says. Plus, for a moment, it seemed possible that climate regulation might make coal power more costly.
The timing was perfect. "A younger generation [had] forgotten about or had not lived through Three Mile Island and Chernobyl," says Edwin Lyman, a senior scientist in the Global Security Program at the Union of Concerned Scientists in Washington, D.C.