By Nina Shen Rastogi
Tuesday, August 10, 2010; HE03
I thought nuclear reactors were an absolute no-go for environmentalists. But I keep hearing them touted as a clean energy source. What are nuclear energy's green credentials?
Some environmentalists are indeed coming around to nuclear energy. That's because the nuclear fission process produces virtually no greenhouse gas emissions, unlike the burning of fossil fuels such as coal and natural gas. (Those two fossil fuels accounted for about 70 percent of U.S. electricity in 2008. Nukes made 20 percent.) Also, fission produces neither sulfur dioxide nor nitrogen oxides, the fossil-fuel pollutants that cause acid rain.
Advocates are fond of noting that nuclear power provides 70 percent of the country's "carbon-free" energy. But nuclear energy isn't really a zero-carbon system, since you still have to build power plants, mine and enrich uranium, and transport processed fuel, all of which typically rely on CO2-emitting fuel sources. Even when the entire life cycle is taken into account, however, nuclear energy warms the planet much less than coal or natural gas. The comparison with renewables such as wind and solar (which also generate emissions in the manufacturing phase) is less cut and dried.
While it's commonly accepted that nuclear energy has a relatively dainty footprint, the question of whether new reactors would be the most cost-effective way to lower electricity-related emissions is still hotly debated. The fuel itself is relatively inexpensive, at least for the time being. But as noted in Time, recent price estimates for a large plant in Florida came in at $12 billion to $18 billion, and that's before you consider the nuclear industry's history of major cost overruns.
Some analysts say alternative methods would yield much more climate-saving bang for our buck than nuclear power. For example, Amory Lovins of the Rocky Mountain Institute argues that we should be investing in general efficiency measures and "micropower," a catchall term that includes cogeneration of heat and electricity, plus renewables other than big hydropower operations.
What about safety concerns? Admittedly, there's a fright factor with nuclear power. But in the 31 years since the partial meltdown at Three Mile Island, there haven't been any emergencies in the United States that remotely approached the severity of that incident, though there have been some close calls.
The government's Nuclear Regulatory Commission has a set safety goal for every reactor in the country: The chance of an accident that results in radioactivity being released to the environment must be no more than one in a million, as determined by probabilistic risk assessment. But even the longest of odds will never satisfy everyone, especially after the cataclysmic drilling accident in the Gulf of Mexico. In recent years, a number of leaks of radioactive water have stoked environmentalist ire, although nearby residents were not exposed to dangerous doses of radiation.
Meanwhile, nuclear proliferation risks remain a prohibitive concern for many experts. And many environmentalists continue to give nukes the stink eye because, as the Lantern noted in an earlier column, after 50 years we still don't have a long-term plan for storing high-level commercial nuclear waste.
But long-term disposal is a problem we're saddled with no matter what: Whether we ramp up nuclear energy production or shut down all our plants tomorrow, we'll have at least 62,500 metric tons of used nuclear fuel to deal with.
Atomic energy also generates other environmental concerns. Like conventional power plants, a nuclear site cranks out electricity using steam-driven turbines. Cooling those operations often requires a whole lot of water, the drawing and releasing of which can affect aquatic wildlife.
Uranium mining can also damage the environment. Mining and milling operators must deal with mill tailings, the radioactive material left over after the uranium has been extracted from the ore, as well as waste rock and radiologically contaminated equipment.
For all this, it's worth noting that uranium is a very efficient energy source: One ton of natural uranium can produce the same number of kilowatt-hours as 16,000 tons of coal or 80,000 barrels of oil.
The Lantern doesn't find herself particularly freaked out by atomic energy. The long-term waste conundrum seems more pressing: After all, isn't the notion that you don't bequeath problems to your descendants a major tenet of environmentalism? At the same time, global warming is itself a dire legacy, and every energy technology has its pitfalls. So if nuclear power can play a role in cooling our planet, the Lantern thinks it deserves to stay on the table.