As part of the nuclear debate I’ve been trying to get my head around the safety question. On the face of it the safety of an electricity production technology should be a straight forward comparison to make. What we want to know is how much energy does a given type of fascility produce over it’s life veruses how many people is it expected to kill. Of course there are some complications and contraversy depending on what you include and what you exclude. Do we include the millions or maybe billions that some think will die as a result of man made global warming? Can we really presume that a nuclear power plant stops killing people after it is decommissioned? Should the energy used in building the fascility be subtracted from the energy it produces over it’s life? To be accurate all of these factors should be considered. We should include deaths in construction and associated mining of construction materials, death in decommisioning, deaths in fuel transport, maintenance deaths, pollution deaths, catastrophic accident related deaths (eg dams collapsing, nuclear plants melting down). However even without all of these perfectly accounted for in the mix we can still get some sense of the safety associated with different technologies.
Most of the numbers I use below come from this article: http://nextbigfuture.com/2008/03/deaths-per-twh-for-all-energy-sources.html
I’ll quote the figures and then try some modest qualification of them. The units used for measuring energy is TWh which stands for Terrawatt hours. A terrawatt is a measure of power. Power is a rate of energy output. So a terrawatt hour is the energy that you get from a terrawatt power source that operates for one hour. 1 terawatt hour = 3.6 × 1015 joules. It is roughly the amount of electric energy that 85000 Australians would use in a year.
The Death Rate is merely the number of lives lost per TWh of energy produced.
Energy Source Death Rate (deaths per TWh)
Coal – world average 161
Coal – China 278
Coal – USA 15
Solar (rooftop) 0.44
Chernobyl alone* 38
The article isn’t entirely clear on what is included and what is excluded but from what I can gather it does including deaths associated with plant construction and the associated mining of construction materials. It isn’t including deaths from man made global warming. It isn’t including deaths from associated transportation (eg road accidents caused by coal trucks).
The “Chernobyl alone” figure isn’t from the article although it comes pretty close to the figure they quote. It is a figure that I calculated based on the article because I couldn’t quite follow the authors logic. My figure assumes that the 1986 Chernobyl accident will ultimately kill 4000 people (the extreme high end estimate cited in the article) and that the plant produced at full capacity from 1983 to 1986 (it actually operated from 1977 to 2000 but not at full capacity). During these years there were 4 generators in operation at the plant each with a capacity of 0.001 TW. Energy assumed is hence 0.004 TW x 3 x 365 x 24 hours = 105 TWh. And the death rate is 4000 / 105 = 38 deaths per TWh. Although we have not accounted for construction associated deaths the real death rate figure is almost certainly lower because 4000 deaths due to the melt down accident is an extreme estimate. Chernobyl is the only nuclear reactor in history to suffer an uncontained nuclear meltdown. Chernobyl continued to operate as a working power plant for 14 years after the accident.