The Curious Wavefunction

The Curious Wavefunction

Musings on chemistry and the history and philosophy of science

Promise or problem? A debate on nuclear power


The association of plutonium with nuclear weapons often leads to a greatly exaggerated perception of its risks. Here, a disk of plutonium which emits low-energy alpha particles is held in the palm of a hand (Image: bubblews)

Yesterday's post about nuclear power sparked a minor but enlightening exchange on Twitter whose culmination is a thoughtful perspective by Nicholas Evans (Twitter handle @neva9257), a research associate at Charles Sturt University in Canberra. Earlier I had posted Nicholas's response in this space but he indicated that he was more comfortable posting it on his own blog since for some reason he thought that my "editorial" comments on his perspective inferred more agreement than what he believes it implies. Below is my response to his post.

Putting risks and rewards in context can turn trouble into opportunity

I thank Nicholas for his articulate comments. Since I agree in principle with most of the things he says, our real disagreement to me seems to be more a matter of degree. Since there’s not much of substance that I disagree with I will thus keep my response short.

We both agree that radiation and its effects should always be considered in context. This analysis certainly goes both ways, but it seems to me that the public and media usually err on the wrong side when reacting to any report of nuclear accidents. For instance, even before any details of the damage from Fukushima was known, people were already talking about a cloud of fallout reaching California and stocking up on iodine pills. To me the precautionary principle seems to go into overdrive when dealing with anything nuclear.

Nicholas raises the all-pervasive question about the effects of low-level radiation. The so-called “linear no-threshold model” is indeed controversial, but controversy does not always imply that opinion should be evenly split; an issue where opinion is split 80-20 can still be considered controversial. To me the evidence against the LNT model (such as the absence of excess cancers in radiation hotspots) seems to outweigh that in its favor. But even if low levels of radiation can cause some damage, we need to put them in context. For instance if we were really worried about low radiation levels we would never fly, or get CAT scans, or live in Colorado. We do all this because to us the benefits of being able to fly, detect potentially serious diseases or live wherever we want outweigh the risks. And that is where we need to ask what the risk of nuclear is relative to other technologies like fossil fuels and what the risk will be relative to the effects of climate change. I think the comparison with geoengineering is a fallacy; unlike completely unproven and potentially world-altering geoengineering schemes, nuclear energy is limited in its scope, has been meticulously studied and tested over fifty years and has a generally impeccable safety record.

Nicholas points out the hurdles that Generation IV reactors face and I agree with him; these kinds of hurdles are faced by any new technology. To me however, the great strength of these reactors is their diversity which allows designers to combine the best features of successful designs. For instance, sodium may be inflammable and corrosive but you can use helium gas in its place. Plutonium may cause certain problems, but thorium is an attractive alternative. In addition these reactors are explicitly being designed with passive safety, so engineers are very mindful of what they need to watch out for. At the very least, considering the benefits these reactors may provide, both private corporations and governments should be supporting research into them on a war footing.

Nicholas also talks about the dangers of the plutonium that many (but not all) of these reactors use, dangers that can lead to proliferation and accidents. As I have mentioned before, there are many safeguards and solutions to the use of plutonium. Reprocessing can make plutonium-containing waste both cheaper and more proliferation-resistant. In addition it would be almost certainly fatal and vastly inefficient for terrorists to try to steal plutonium from a reactor and build a bomb with it. Plutonium is one of those mythical substances which seem to generate more heat than light; it has a relatively long half-life and is therefore not intensely radioactive, and can cause real damage only through inhalation. Even when inhaled, the element causes a tiny increase in lifetime cancer risk over the background rate; in fact many of us have measurable amounts of the element in our bodies. As in other nuclear-related matters, the association of plutonium with nuclear weapons often leads to a greatly exaggerated perception of its dangers. It’s really about psychology, not physics, chemistry or biology.

Finally, Nicholas talks about the political hurdles in the use of nuclear power, its association with secrecy and the tight controls that have been exerted on it by both government and private corporations. I am in complete consensus that ignoring these political problems would be ignoring the elephant in the room. He mentions that 10 utilities control 70% of nuclear power plants, but it’s also worth mentioning that it’s the regulatory regime, public disapproval, the general lack of enthusiasm and the dearth of trained nuclear engineers (a point with which I completely agree) that thwarts more utilities from stepping in. The government has not been friendly to utilities since Three Mile Island (a non-event as far as human cost was concerned), and it is only by giving utilities more flexibility and not imposing unreasonable constraints of cost and time that can encourage further investment in terms of technology, safety, investor interest and education.

Nicholas says that “changing these institutions, allowing innovation to happen securely, and introducing competition into the nuclear marketplace are as much social and political changes as they are technical.” and I could not agree more. Competition especially is the key to improved reactor designs and that is where the government and public education are both important. Yet we cannot ignore the disproportionate attention that technical and scientific issues often get, attention that routinely exaggerates risks at the expense of a reasoned discussion of tradeoffs and realities. In addition technical issues are often confused with political ones, leading many to believe that the problems are much more intractable than they actually are; for instance people constantly talk about waste or proliferation or radiation as if their real problems were all scientific, when the truth is that most of the stumbling blocks are political. If we all had a sure grasp of the real benefits and drawbacks of the science and technology and simply talked about the political hurdles it would already indicate much progress. And I welcome the time when we are ready to do this.

The views expressed are those of the author and are not necessarily those of Scientific American.

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