The Risk of Energy Production

Living is not a risk-free endeavour to be sure. Consider the following table showing deaths per TWh for all energy sources. Note that rooftop solar power is actually more dangerous than Chernobyl.

• Source: http://nextbigfuture.com/2008/03/deaths-per-twh-for-all-energy-sources.html from different energy sources, which draws on the ExternE calculation of death/TWh (pdf 124kb) [local archive (pdf 124kb)]. Find out more about ExternE.
• A terrawatt (TW) of power is 10¹² watts = 1,000,000,000,000 watts = million, million watts. A TW of power for a time period of one hour gives 1 TWh of energy.
• A gigawatt (GW) of power is 10⁹ watts = 1,000,000,000 watts = thousand, million watts. A GW of power for a time period of one year gives 1 GWy of energy. Since a typical large power plant is about 1000 MW (= 1 GW), a GWy is the amount of energy a plant produces in one year. To convert from TWh to GWy, multiply by 8.76.

Ontario uses about 20,000 MW ( = 20GW = 0.02 TW) of electricity on average and about 50% of that is produced by nuclear power plants which is 0.01 TW. This is the energy production rate per second, ie. power. So Ontario produces, on average, about 0.01 TWh (terrawatt hour) in an hour from nuclear. That's about 88 TWh per year. From the above table that should have led to 0.04 x 88 = 3.5 deaths per year. After 40 years or so of nuclear power production in Ontario there should be more than 100 deaths accumulated. I challenge anyone to name me the names. As far as I know, the actual death toll in Ontario due to nuclear power plant radiation is zero, 0, nada, zilch. But I suspect that there have been industrial accident related deaths of the common kind: falls, electrocution, etc. So let's accept the numbers in the table as more or less correct. The figure of 0.04 deaths per TWh in the above table included all nuclear worldwide, including Chernobyl. Given that Chernobyl deaths dominate the nuclear death stats, the 'death per power generated' estimates will depend mainly on the cancer estimates for low levels of radiation.  The erroneous use of LNT for risk estimates raises its ugly head once again.

The 1410 deaths per year per plant is grotesque even for coal.  I guess it depends on how you attribute deaths.  The World Bank is reported (http://www.pri.org/business/global-development/thousands-of-deaths-because-of-china-s-coal-energy2500.html ) to have estimated there are 700,000 deaths per year due to air pollution and 1,600 per year in coal mining accidents.  According to wikipedia, China has 484 GW of coal fired power.  If you attribute most of the 700,000 air pollution deaths to coal you get about 1400 deaths per GWyr.  These are staggering numbers.  Now one cannot attribute all those deaths to coal but it is recognized that coal is a major contributor to air pollution in China. Are the numbers for coal believable?

If one focuses on just accident data, the numbers are significantly lower across the board. The January 2005 report from the Paul Scherrer Institut (http://gabe.web.psi.ch/pdfs/PSI_Report/SVGW_PSI-Bericht-05-01.pdf) [local archive (pdf 2.2Mb)] gives:

(a) First line: Coal non-OECD w/o China; second line: Coal China
(b) Banqiao and Shimantan dam failures together caused 26,000 fatalities
(c) Latent fatalities are treated separately.

They convert these numbers to a GWy basis and report:

From the above, whether just focusing on accidents or considering all the externalities (which are admittedly fraught with uncertainty), nuclear as a source of power has proven to be a very safe option.

Yes it does indeed have a huge potential for large radiation releases and very many deaths. One might ask what would be the consequences if in the worst-case scenario the reactor goes into full meltdown? That is perhaps not a meaningful question to ask. It is a bit like asking how many people could be killed by a big sharp knife. Presumably the entire world population but to orchestrate it would be inconceivable. There is enough water in Lake Ontario to kill the world, etc. Chernobyl 'released' its entire inventory which theoretically is enough to kill the world - if somehow we were all exposed to the core. Truth is, a few locals may die if containment is lost, more would get sick and recover, some would get cancer later on and may or may not live. Read more on the consequent side of radiation risk assessment. The actual consequences (deaths and injuries) are, by deliberate and careful design, far, far less than the worst case one can imagine. One cannot say that there will never be a major containment breach and a release of dangerous amounts of radiation. But as emotions run high, the wise would keep the facts - the reality - in mind. Nuclear is a low death-rate option, perhaps the lowest. And a death is a death, no matter the cause.

At current costs, solar and wind are far more expensive than nuclear, they are intermittent sources, and hydro capacity is limited. So the reality is that a rejection of nuclear translates to an expanded use of fossil fuels - and probably many additional deaths. With China and India moving out of poverty which requires much more power than they have now, the world demand for power is rising dramatically in spite our best efforts to conserve. It seems pretty unethical to me to reject nuclear knowing the alternatives will lead to far more deaths.

Further Reading

• Seeker Blog - Archive for the 'Nuclear Risk Assessment' has a good summary and links to other sources. [local archive (pdf 367kb)]
• Learning About Energy - Much of What You Know Simply Isn't So, hosted by Ted Rockwell. Tons of great information here. See The Nuclear Power Safety Record for instance.
• PBS Frontline - Fatality Comparison Statistics - Nuclear vs. other endeavours.
• "Any decision relating to risk involves two distinct and yet inseparable elements: the objective facts and the subjective view about the desirability of what is to be gained, or lost, by the decision. [O]nly the pathologically risk-averse make choices based on the consequences without regard to the probability involved. [O]nly the foolhardy make choices based on the probability of an outcome without regard to its consequences.
  Bernstein, Peter L. Against the Gods, the Remarkable Story of Risk