"The expected number of core damage accidents during the scenario (global growth between 2005-2055) with current technology would be 4."
- The Future of Nuclear Power, Massachusetts Institute of Technology, (2003)
When compared to other energy sources, the risks of a major release of radiation due to a catastrophic nuclear reactor accident or from a terrorist attack make it a uniquely dangerous energy option. A major release of radiation would have devastating consequences to public health, the environment, and our economy. If nuclear power does enjoy a renaissance in the coming years, the risks will only increase. This is disconcerting when you consider the industry still suffers from poor regulation and its current fleet is aging rapidly, which will only increase the risks.
Scientists point out that the nuclear industry, like all complex technological systems, will experience the "bathtub effect." That is, if plotted on a graph with the x-axis being time and the y-axis being risk, at the beginning of a technology's development the risk will be high, but once technological "kinks" are sorted out and experience is gained, the risks will drop significantly and possibly flatten out. Over time, the risks will once again rise as the equipment begins to age and fail and the workforce is ill-equipped to face these new challenges out of complacency, over-confidence, and/or lack of training. This graph, then, will look like the outline of a bathtub.
For more information on specific risks associated with nuclear power plants, click below:
Risks
What is the probability?
What are the risks?
Most of the world's 400-plus reactors in operation today are light-water reactors that need constant cooling to prevent a meltdown of reactor fuel. If a reactor loses its cooling ability due to an accident or deliberate act, the reactor fuel would be damaged by the extreme heat within seconds. The now molten fuel would melt the steel covering the reactor core, come in contact with the concrete floor of the building and release large amounts of gas that could cause the entire building to explode. The radioactive elements that would be released would include iodine-131, cesium-137, and strontium-90; all very biologically damaging and would lead to severe health impacts to surrounding communities.
The last major study to look at the impacts of a major release of radiation from a nuclear power plant was conducted by Sandia National Laboratory and concluded that, in a worst-case scenario, the accident would result in tens of thousands of deaths from short terms radiation exposure and long-term cancers, and cause hundreds of billions of dollars in damage.
The worst reactor accident in history occurred in 1986 at the Chernobyl nuclear power plant. Although Chernobyl was not a light-water reactor, the consequences are important to note. Over 200,000 people were forced to evacuate the area following the accident and many thousands of acres of agricultural land were abandoned. The area remains very radioactive to this day and played a major role in turning public opinion decidedly against nuclear power. Whether by human error, sabotage, attack, technical failure, or all of the above, nuclear power presents unique risks to human health and the environment.
What is the probability?
"We should remember that risk assessment data can be like the tortured spy: if you torture it long enough, it will tell you anything you want to know."- William Ruckelshaus, former EPA director.
It is clear then that the consequences are high but the question remains: what is the probability that major nuclear reactor accident could occur again? This is the most unclear aspect of the nuclear power program. A nuclear power plant is a highly complex operation that requires a perfect level of performance at all levels: regulatory, operations, and even maintenance. Furthermore, attempts to assess risks and probabilities of accidents are flawed because human error and technical failure are incredibly difficult, if not impossible, to predict.
And if we remember that nuclear power is subject to the "bathtub curve," we see additional concerns because most nuclear reactor accidents occurred within the first 3 years of their operation. While the safety record has stabilized over the last 20 years, most reactors are aging rapidly and were never designed to operate for more than 40 years. Coupled with the plans to build a whole new fleet of reactors worldwide including some with new and unproven designs, we face an increased risk of reactor accidents over the 50 years. Dr. Brice Smith concludes in his book, Insurmountable Risks, that with the high-end predictions of a nuclear power expansion "there would be a 50-50 chance that three or more (Three-Mile Island type) accidents will have occurred around the world by mid-century."
References:
Wiliam D. Ruckelshaus, "Risk in a Free Society", Risk Analysis, Vol. 4 No. 3, 157-162 (1984)
Brice Smith, Insurmountable Risks, IEER, p. 272 (2006).
