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Sunday, 4 October 2009

Why is nuclear power so ineffective in combating greenhouse warming ?

Why is nuclear power so ineffective in combating greenhouse warming ?

To the folks who bring us nuclear power, this year's drought is one of the best things that could have happened.

Their logic goes like this. The drought is widely perceived to be a first sign of the greenhouse effect -- the global warming caused by a buildup of atmospheric pollutants. Primary among those pollutants is carbon dioxide, which comes from the burning of coal, oil, and gas. Nuclear power produces no carbon dioxide. Therefore, to prevent more and worse droughts, sea-level rises, floods, and other climatic horrors, we should nuclearize in a big way.

The media have been captivated by this reasoning. Time magazine ended its July 4 article on the greenhouse effect with the sentence: "As Democratic Senator Wendell Ford of Kentucky pointed out last week, the only major energy source that might replace fossil-fuel plants is nuclear power." And Newsweek said in its July 11 issue: "One irony is that the energy source most ready to fill the breach left by coal and oil is the environmentalists' nemesis: nuclear power."

The problem with this apparently obvious conclusion is that, like many apparently obvious conclusions, it doesn't hold up when you run out the numbers. Bill Keepin and Gregory Kats, energy analysts at Rocky Mountain Institute in Old Snowmass, Colorado, have gone to the trouble of figuring out exactly what it would take for nuclear power to "fill the breach." Their numbers suggest that there is indeed a solution to the climate change problem -- but the solution is not nuclear.

Keepin and Kats start by supposing that the world's nations come to an unprecedented agreement to replace all present and future uses for coal with nuclear power, and to accomplish that within 40 years. (They choose coal, rather than oil and gas, because coal is the greatest carbon-emitter of all the fossil fuels, and because nuclear can substitute directly for coal's major use, which is making electricity.) Keepin and Kats also make the deliberately optimistic assumption that it will take only six years to build each nuclear plant and that the cost will be $1000 per installed kilowatt capacity (which is the reported current cost in France; in the United States the cost is three times higher.)

If the world's energy demand grows at the top of the range of present forecasts, it will increase by 3.5 times between now and 2025. Under that scenario Keepin and Kats calculate that a substitution of nuclear for coal would require bringing on nuclear power approximately equal to ALL the world's present energy production. By 2025 the world would need 8000 large nuclear plants, as opposed to the 350 operating today. New plants would have to come on line at an average rate of one every 1.6 days, at an average cost of 787 billion dollars per year, for 38 years.

Even with this unimaginable increase in nuclear power, carbon dioxide emissions would grow to be 65 percent higher than they are now. Greenhouse warming would be rampant. The drought of '88 would look like a pleasant cool spell.

If energy demand goes up at a slower rate -- doubling by 2025 -- and again nuclear were systematically substituted for coal, one new nuclear plant would be required every 2.4 days, at a cost of $525 billion annually. To pay their share of this buildup, the Third World nations would have to double their current levels of debt (never mind the problem that no one would lend them that much). There would be 18 times as many nuclear plants as there are today. Carbon dioxide emissions would grow until the turn of the century and then slowly fall, but at all times they would be higher than they are now. The greenhouse effect would go on getting worse.

Why is nuclear power so ineffective in combating greenhouse warming in these calculations? Because it only provides electricity, which accounts for only one-third of fossel-fuel use. Because fossil fuel use accounts for only about half of the greenhouse problem (the rest comes from deforestation and from gases other than carbon dioxide). And because even with generous assumptions about construction time and cost, nuclear starts from too low a base and takes too much time and money to take over a major part of the world energy production.

The massive buildups of nuclear power assumed in the Keepin and Kats calculations could never really happen. Construction times of U.S. plants are more like 12 years than six. Costs around the world are typically two, three, even five times higher than Keepin and Kats assumed. Even if the managerial capacity were available to construct so many plants so fast, the drain of that much capital into nuclear construction would slow or stop the very economic growth that is assumed to require so much power in the first place. And of course the problems of nuclear power -- high cost, intractable and dangerous wastes, evacuation planning, threats to public health, decommissioning, diversion of fissile materials into bombs, vulnerability to terrorism, and political unpopularity -- all those problems would escalate.

Now for the good news. There are energy scenarios, much easier and cheaper than the high-nuclear ones just described, that can greatly ameliorate greenhouse warming. They involve state-of-the-art design to meet energy needs in the most efficient way possible. That doesn't mean what most people think of as conservation -- cold rooms, warm beer, and general deprivation. It means efficiency -- being smart about warming the rooms and cooling the beer, so as to use the least possible amount of energy for the purpose.

Most efficiency improvements are fast and cheap compared to nuclear power, and unlike nuclear, they apply to every kind of energy use, including transportation. For example, just changing all the light bulbs in America to the most efficient ones now available could shut down at least 40 large coal-fired power plants and save the nation $10 billion a year. New office buildings could be constructed in the most energy-efficient way at no increase cost, and over fifty years they would save the equivalent of 85 power plants and two Alaska oil pipelines. If the average fleet efficiency of U.S. cars doubled from the present 18 miles per gallon to 36, automobile carbon emissions could be cut in half (and another half if the fleet reached the 78 mpg of some current five-passenger full-size test vehicles.) That could be accomplished within one or two turnover times of the fleet -- 12 to 24 years -- at no cost, and as a side benefit there would be large reduction in urban air pollution, acid rain, and military costs in the Persian Gulf.

A number of studies have worked out the possible results of a major global commitment to energy efficiency. According to one of them, the industrialized nations could maintain annual GDP growth rates of 1-2 percent per year and stil cut per capita energy demand at nearly today's rates. The result would be a slight decline in carbon emissions from today's levels. Add a shift to solar energy, stop deforestation, and start reforestation, and the greenhouse problem could be reduced dramatically.

The folks who bring us nuclear power will be quick to point out that nuclear could be added to an efficiency scenario to reduce carbon emissions even further. Keepin and Kats do a calculation assuming a sixfold expansion of nuclear power by 2025 (a new plant every 7.5 days at an annual cost of $178 billion) IN ADDITION TO a major commitment to energy efficiency. In that scenario carbon emissions are about half of what they are today. About 38 percent of that reduction is due to nuclear substitution for coal.

Which is not, however, an argument for adding nuclear power to the list of possible solutions to the global warming problem, primarily because nuclear is so enormously expensive that it drains money away from better options. At current U.S. costs for nuclear and for efficiency, a dollar spent on efficiency displace nearly SEVEN TIMES as much carbon as a dollar spent

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