Climate Bluff

The nuclear industry likes to claim that nuclear power plants produce no carbon dioxide at all1. This is just not true.

It is true that the act of burning uranium in a nuclear reactor doesn't directly release carbon dioxide in the same way that coal or gas do (although some nuclear power stations do release Krypton-85, a climate gas, to the atmosphere). But to say that that means that nuclear power is zero-carbon is like causing a road accident and then saying that you didn't hit anyone (OK, your car hit them, and you were driving the car but since you didn't physically make contact with the other person yourself it doesn't really count, does it?).

But any sensible analysis of the environmental impact of nuclear power has to look at the whole cycle: from mining, extracting and enriching the uranium through building and operating the power station and right through to the end of the process of looking after the waste. And that's where the industry's zero-carbon claims come unravelled.

Mining and extraction of uranium involves the use of large, fossil-fuelled, machinery and other energy-intensive industrial processes. Since relatively few countries have significant uranium deposits the ore must also be transported around the world. As we use up the existing deposits the quality of the uranium ore is likely to decrease, requiring more rock to be mined and processed to produce the same amounts of uranium. Any new uranium deposits are likely to be more difficult to extract (either due to quality or depth). As such, the carbon emissions from uranium mining are only likely to increase in the future2.

The construction of a nuclear power plant takes many years and many tonnes of metal, concrete, etc. all of which results in greenhouse gas emmissions.

The other big factor here is nuclear waste. As noted elsewhere on this site, the nuclear industry (and the governments and regulators who are backing its expansion) are desperate to find a "solution" to the problem of nuclear waste in which the requirement for human supervision of the waste ends after a relatively short period of time3. This is because any calculation of the full life-cycle cost of a nuclear power plant (whether in financial or carbon terms) is going to come up with a very large number indeed if the waste will require human supervision for hundreds of thousands of years.

A recent paper from a researcher at Stanford University4 estimates the lifecycle emissions of new nuclear power plants as 9-70 g-CO₂e/kWh5. The low estimate there (9) is an estimate from the nuclear industry6 An academic study (cited in the above paper) which reviewed 103 lifecycle studies of nuclear energy found an average of 66 g-CO₂e/kWh.

Note that even a lifecycle analysis of a decommissioned nuclear power plant can be at best an estimate since no country in the world has a fully-functioning system for dealing with spent nuclear fuel in the long-term - and even if they did, we won't know for hundreds, if not hundreds of thousands, of years what remedial measures might be necessary, how long human monitoring will have to continue in practice, etc. Any estimates of the full lifecycle emissions of nuclear power should start with the words "at least ..."

The nuclear industry is very fond of comparing nuclear to fossil fuels and usually to the dirtiest fossil fuel of all, coal. They are less fond of comparing nuclear to renewable energy sources. Nevertheless, this paper concludes that nuclear is essentially on a par with a Coal-with-Carbon-Capture-and-Storage (CCS)7 power station and significantly behind renewables. "Coal with CCS and nuclear will provide less benefit with greater negative impacts."

There is another factor to consider here. This is what economists call "opportunity costs". This is the cost (or, in this case, the CO₂ generated) by continuing to use the current power stations while we build new ones. This is a huge problem with nuclear power, which has historically always run over-budget and behind schedule8. The report quoted above rates the opportunity costs for nuclear as higher than for any other technology they consider, noting that "For nuclear, the opportunity CO₂e is much larger than the lifecycle CO₂e". This is an especially critical issue in climate change terms, with most scientists saying that we have a relatively short window to effect major change before climate change becomes uncontrollable (at least within a range which is comfortable for humans to live).

In summary the nuclear industry's zero-carbon claims don't hold up. Nuclear power is a significant producer of greenhouse gasses. Not on the scale of old-fashioned coal power stations but still significant and significantly more than renewable sources. And even if it was as low carbon as they claim, we couldn't build enough nuclear power plants quickly enough, even if we wanted to. All in all, nuclear power is no part of the solution to climate change.

1. 1. See, for example, this story where the station director of Sizewell nuclear power plant, in England, when faced with protests as part of the Climate Camp in 2007, claims "For us it's a surprise. We believe we're the only electricity generator that does not produce carbon dioxide emissions..."
2. 2. See for example this article about this paper. The paper also points out that the energy required to produce the chemicals required to extract the uranium are generally not included in the emissions figures for uranium mining ("Critically, the data for all mines does not account for the additional embodied energy required for reagents such as solvents (e.g., kerosene, amine), sulfuric acid, oxidants (e.g., hydrogen peroxide, manganese dioxide or MnO2), lime, and so on. This would add further energy costs to uranium production.")
3. 3. Usually 100-200 years
4. 4. Dr. Mark Z. Jacobson, "Review of Global Warming Solutions" (available in PDF format)
5. 5. Grammes of carbon-dioxide equivalent per kilowatt hour. There are many greenhouses gasses, some more effective that others. In order to compare different technologies emissions of other gases are converted to the quantity of CO₂ which would have the same effect, it's carbon dioxide equivalent, CO₂e
6. 6. While the nuclear industry in its PR likes to claim zero-carbon, in it's academic-style reports it has to admit to some.
7. 7. An unproven technolgy which attempts to capture the carbon dioxide released when coal is burnt and bury it underground again
8. 8. See, for example, Olkiluoto 3