Saturday, January 19, 2008

Solutions to Global Warming: Part 3

In this article we'll cover the arguments in favor of nuclear energy. We'll cover the arguments against in the next article.

4) Nuclear Energy

Pros of Nuclear Energy

Nuclear energy has the best safety record of any energy source. No member of the US public has been killed or injured by any nuclear plant. This is a key point, because many people are under the impression that nuclear plants are wildly dangerous. The Chernobyl accident in Ukraine in 1986 showed what the actual scale of an accident could be without normal safety provisions. After the accident, the World Health Organization did an extensive investigation and continual followup; its findings were that actual deaths have numbered less than 50 and there could be as many as 4000 fatal cancers in the future.[source] As tragic as that is, it doesn't approach the death rate due to burning coal. Even in the US, tens of thousands of people die every year just from the pollution from generating electricity with fossil fuels.[Abt Associates Report, Exhibit 6-4] More important, the accident at Three Mile Island in Pennsylvania in 1979 totally destroyed the reactor but resulted in no adverse health effects, which validated the defense-in-depth designs used in all US reactors.[source]

Nuclear energy is clean. Since reactors emit no pollutants they are as clean as any of the renewable energy sources that have been suggested.

Nuclear energy is abundant. At current usage, the world's known uranium reserves producible at less than US$60 per pound of U3O8 will last 85 years. Geologic data show that the supply is over 600 years. At higher prices, the supply is even greater. With advanced fuel cycles, the proven reserves would last over 2500 years.[source]

Nuclear energy is economical. Presently, it is cheaper than any energy source except hydroelectricity. Both of them are cheap because the capital costs have all been paid back. Here are average operating costs in the US in 2005, in cents per KWH[source]:

Nuclear 1.816
Fossil Steam 2.769
Hydroelectric 0.886
Gas Turbine and Small Scale 5.885

For new plants, of course, the cost would be higher because of the capital costs. Here are comparisons for different energy sources [source]. The costs are in UK pence/KWH.

Gas-fired CCGT
Nuclear fission plant2.3
Coal-fired pulverised-fuel (PF) steam plant2.5
Coal-fired circulating fluidized bed (CFB) steam plant2.6
Coal-fired integrated gasification combined cycle (IGCC)3.2
Onshore wind farm3.7
Offshore wind farm5.5
Wave and marine technologies6.6

Note that the coal-fired electricity costs more than nuclear, which no doubt is because advanced-technology plants are being considered in order to minimize pollution. If older-technology plants were being priced, the cost would be somewhat less, probably less than any of the costs shown.

Nuclear energy is effective against climate change. Comparing life-cycle greenhouse-gas emissions, nuclear ranks with the cleanest of all electric-energy sources in tonnes CO2-equivalent per GWeh.[source]

Combined-cycle natural gas 469
Nuclear fission15
DT fusion9

Furthermore, most of the solutions to replacing petroleum-based motor fuels require hydrogen and the most efficient way to convert water to hydrogen is with high-temperature processes, at temperatures nuclear reactors can provide. In particular, hydrogen can be added to biomass to triple the output of biofuels; that could make biofuels a major alternate fuel.[source] The nominal efficiency is over 45%.[source] But the heat left over from the conversion can be used to generate electricity, so the hydrogen production is nearly 100% efficient.

So those are the points in favor of nuclear energy. In the next article we'll go over the arguments against.

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