|Fig. 1: A view of the nuclear reactor in Chernobyl. (Source: Wikimedia Commons)|
Several factors are important when comparing different ways of producing energy. Among these are cost of production, ability to scale, environmental impact, sustainability, and associated health risks. In what follows, we look at several different types of dangers of energy production and compare the risks associated with nuclear energy with those associated with coal and other fossil fuels.
When thinking of safety with regards to nuclear energy, it is easy to think first of disasters such as Three Mile Island, Chernobyl (see Fig. 1), and Fukushima. Of these three events, the only one that caused deaths was Chernobyl for which death estimates are slightly above 50 people.  A 2007 study of energy production in Europe assessed accident related risks of several different sources of energy production. The results showed that nuclear energy production averages 0.012 deaths due to accidents per TWh of energy produced.  In contrast, coal production averages 0.12 deaths due to accidents per TWh.  Indeed, nuclear energy also had a lower number of accident related deaths than all other forms of energy production studied (Oil, Gas, and Lignite). 
Another potential form of risk is due to air quality issues that result from production of energy. The same study cited above also came up with estimates of this category. For nuclear energy they estimate 0.052 air quality related deaths per TWh and 0.22 incidences of serious illness per TWh.  In contrast, coal is estimated to cause 24.5 air quality deaths per TWh and 225 incidences of serious illness per TWh, a full three orders of magnitude higher than nuclear.  It should be noted that this categorization is somewhat misleading, as it includes air quality related affects related to mining inputs as well as using them, so some portion of the high numbers for coal can be attributed to the hazardous nature of coal mining.
One significant safety issue that is specific to nuclear energy is that of nuclear waste disposal. The production of nuclear energy produces nuclear waste which is highly hazardous to human health and must be disposed of properly. Many of the byproducts of nuclear energy have half-lives on the order of thousands of years.  Therefore, they will be highly radioactive and dangerous for a long period of time. This creates the need for a safe location for long term storage of nuclear waste, but such a solution has not yet been found.  Because the dangers of this type are highly dependent on disposal method and are potentially relevant for hundreds or even thousands of years, they are quite hard to quantify.
Another danger of nuclear energy is that certain types of nuclear reactors create byproducts that can be processed and used as fuel for nuclear weapons.  In fact, India began its nuclear weapons program using plutonium extracted from CIRUS reactors.  Accordingly nuclear energy can be though of as a risk to national security and general global peace. However, just as with nuclear waste disposal issues, the danger associated with this increased availability to plutonium for weapons is very hard to quantify and depends heavily on global politics and other such events going forward.
Overall, both nuclear energy and coal come with significant risks. Although coal is more dangerous in several of the categories that are easier to quantify, nuclear energy carries with it other risks that are fundamentally difficult to quantify. Therefore it is very hard to give a definitive answer as to the safer of the two options. Either way, the debate over the safety of nuclear energy will surely play an influential role in the future of global energy production.
© William Marshall. The author warrants that the work is the author's own and that Stanford University provided no input other than typesetting and referencing guidelines. The author grants permission to copy, distribute and display this work in unaltered form, with attribution to the author, for noncommercial purposes only. All other rights, including commercial rights, are reserved to the author.
 D. Brown, "Nuclear Power Is Safest Way to Make Electricity According to Study," Washington Post, 2 Apr 11.
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