First in a two-part series.
The process used to generate electricity from decaying nuclear fuel creates a laundry list of toxic and radioactive byproducts along with plutonium, a man-made element that can be used to make nuclear weapons.
What you won't find on that list, however, are substantial amounts of greenhouse gases, including carbon dioxide, nitrous oxide and methane. Nuclear energy may not be clean, but without it, a climate-neutral energy system may be far more difficult and expensive to achieve.
Today, nuclear power accounts for a majority of the United States' carbon-free electricity production and trails only hydroelectric power -- 13 percent to hydro's 16 percent -- on the world stage. Still, nuclear has been long reviled by the environmental community for the toxic nature of its byproducts and the potentially catastrophic dangers posed by power plant accidents.
But now the specter of a different catastrophe, rapidly accelerating climate change, is beginning to enter the court of public opinion. It is drawing some new adherents from both scientific and environmental circles who say nuclear will be needed as a part of the low-carbon energy mix of the future.
Those views were aired this week in an open letter from four pre-eminent climate scientists: Columbia University's James Hansen, Kerry Emanuel of the Massachusetts Institute of Technology, the Carnegie Institution's Ken Caldeira and Tom Wigley of the National Center for Atmospheric Research.
"While it may be theoretically possible to stabilize the climate without nuclear power, in the real world there is no credible path to climate stabilization that does not include a substantial role for nuclear power," they wrote.
That position got another boost yesterday, with the airing of the pro-nuclear documentary "Pandora's Promise" on CNN. The documentary follows environmental campaigners-turned-nuclear proponents (ClimateWire, June 17).
Both the scientists and environmentalists in question have pushed back against anti-nuclear resistance from activists and governments, drawing attention to "next generation" nuclear technologies that they say can help solve the waste problem, reduce safety problems and trim the extraordinary costs associated with plant construction.
But will there be a next generation? Germany has vowed to phase out nuclear power and Japan has greatly reduced it, and in the United States, for the most part, existing plants are aging and the market is not receptive to new ones.
Pricey plants vs. cheap gas
Two nuclear reactors are currently under construction in the United States, both of them in regulated power markets. In the deregulated markets, where economic factors reign, four plants have announced closure this year. Two of them are being closed due to mechanical or structural failures. Another two -- the Vermont Yankee plant in Vernon, Vt., and Kewaunee Power Station near Green Bay, Wis. -- have simply been ruled uncompetitive with today's ultra-low natural gas prices and the declining cost of wind power.
The industry blames the closures on market shortsightedness. "There is absolutely nothing wrong with these plants, but there is something seriously wrong with the markets in which they are operating," said Richard Myers, vice president of policy development with the Nuclear Energy Institute, speaking with reporters earlier this year.
Deregulated markets fail to recognize -- and subsequently value -- the services and security provided by nuclear power's near-constant operating capacity, said Paul Genoa, senior director for policy development at NEI. He acknowledges that the construction of conventional nuclear power plants is expensive: For example, the cost of two units under construction at Southern Co.'s Plant Vogtle in Georgia has risen above $15 billion. But he noted that the vast majority of those costs are paid upfront, providing price stability for decades into the future, he said.
Fitting in with renewable energy
Mechanically, nuclear plants generate power at about 90 percent of their operating capacity, compared with 62 percent for a coal-fired plant and 34 percent for wind power, according to data from the Energy Information Administration.
That means nuclear power can most efficiently complement a renewable energy economy when that high operating potential is realized, Genoa said. "Some of the newer plants being proposed are designed so they can load follow," or move power production up and down when needed to fill the gaps in intermittent wind and solar, he said. "We don't see that as an efficient way to operate a system."
Instead, nuclear might work best when hybridized with other energy systems, backing up renewables during periods of low output and performing other useful functions such as splitting water into hydrogen fuel or pumping water into high storage ponds, for example, as a way to store energy until renewable generation drops off, he said.
And of course, because it generates no significant levels of greenhouse gas emissions, nuclear power could benefit from a price on carbon emissions or a similar incentive relative to gas and coal.
"Let's be clear: I think nuclear is competitive today in regulated markets that, because of resource planning requirements, are looking out over a 40-year time period," Genoa said. "The places where we're seeing new construction -- Georgia, South Carolina -- believe that their investment will pay off."
He added, "But can you build new nuclear in deregulated markets states? The answer is no. The market is broken."
The future isn't now
The tough economic conditions have become central to critics' arguments as well. When it comes to abating carbon, "nuclear power is one of our most expensive options," said Mark Cooper, a senior research fellow for economic analysis at the Vermont Law School Institute for Energy and the Environment. "The simple answer is, if you pay too much for carbon, you're going to buy less of it. And there are numerous less costly options today that can be utilized and deployed before new nukes come online."
The next-generation technology currently under development -- reactors like Argonne National Laboratory's integral fast reactor or TerraPower's traveling wave reactor, designed on a smaller scale to burn the country's vast store of spent nuclear fuel -- is still a decade out in terms of deployment, if not more, he said.
"Nuclear is inherently uneconomic because it's based on a catastrophically dangerous resource wrapped in incredibly complex technology," he said. "Like we saw at Fukushima, that's always going to be confronted by external design challenges."
Despite disagreements over the long-term prospects of nuclear energy and its valuations in energy markets, both critics and proponents seem to be in agreement that new nuclear capacity, in the United States at least, won't be coming in the near future (ClimateWire, May 23, 2012). And if it does, it will likely look much different from the legacy plants operating today.
As more intermittent renewables come online over the next decade, utilities and grid operators will need to look to other technologies and energy sources to fill the gaps -- or eliminate them.
Tuesday: Will flexibility and a smarter grid help?