See also this important analysis: M. V. Ramana, Beyond our imagination: Fukushima and the problem of assessing risk, Bulletin of the Atomic Scientists, 19 April 2011.
This paper was written by Jim Green. The January 2011 original has been corrected and updated in May/June 2013.
Comparisons of the risks associated with different energy sources need to consider several factors:
- Power plant accidents.
- Accidents at other stages of the energy chain (e.g. uranium mining, spent nuclear fuel stores).
- Impacts of routine operations and emissions.
- Attacks on power plants and other stages of the energy chain (by nation-states or sub-national groups).
- Weapons/WMD proliferation risks.
Claims that nuclear power is safe, or that it is one of the safest energy sources, often rest on flawed assessments of the risks and impacts of power plant accidents, and completely ignoring the other four aspects of risk assessment. A typical example is the Switkowski Report (2006, p.77) which includes a table on fatal accidents in the worldwide energy sector from 1969–2000. The figures are given in terms of deaths per gigawatt-year (the amount of electrical energy generated by a 1 GW power plant over the course of one year of continuous operation):
|Hydro||0.561−4.265 (higher figure includes a major dam accident in China in 1975)|
The Switkowski Report (2006) states: “The record of such accidents shows that the nuclear power industry is significantly safer than other large scale energy-related industries.”
However when accidents are properly accounted for, and when routine emissions across the energy chain are considered, renewable energy sources are shown to be i) less hazardous than fossil fuels and ii) with the exception of biofuel/biomass, renewables are safer than nuclear power (and of course renewables do not contribute to WMD proliferation whereas there are extensive, repeatedly-demonstrated links between civil nuclear programs and WMD proliferation).
There is no doubt that average safety standards have improved since the Chernobyl disaster. Improvements can be seen both at the technical level and also the social level (improvements in the management and operation of reactors). Nevertheless, the potential for catastrophic accidents remains. Serious challenges confront the industry, including the following:
- The ageing of the global nuclear workforce and the consequent loss of skills both for the operation of nuclear facilities and for regulatory bodies.
- Pressures arising from the expansion of nuclear power, such as increased skills shortages.
- Safety challenges will be greater in countries developing nuclear power for the first time, especially countries with limited technical and industrial bases, inadequate regulation, or widespread corruption.
- The ‘bathtub effect’ − a likely scenario in the coming 20 years is that an increasing majority of the global fleet of power reactors will be very young or very old, the two phases of a reactor’s lifespan when they are most accident-prone.
- Inadequate regulation in a number of countries, including advanced nuclear countries such as the US and Japan.
- The ongoing potential for commercial imperatives to reduce safety margins in a number of ways.
- The push to limit or abolish public participation in decision-making and licensing processes, a push which is driven by commercial imperatives and could adversely effect nuclear safety.
- The ongoing potential for attacks on nuclear plants whether by nation-states or sub-national groups (terrorists).
Moreover, improvements post-Chernobyl have been uneven. In Japan, for example, safety and regulatory standards have been appalling, resulting in numerous accidents including the March 2011 Fukushima disaster. The Nuclear Accident Independent Investigation Commission (NAIIC) − established by an Act of Parliament − states in its 2012 report that the Fukushima disaster was “a profoundly man-made disaster that could and should have been foreseen and prevented” if not for “a multitude of errors and wilful negligence that left the Fukushima plant unprepared for the events of March 11″. The NAIIC report goes on to note that the 160,000 evacuees “continue to face grave concerns, including the health effects of radiation exposure, displacement, the dissolution of families, disruption of their lives and lifestyles and the contamination of vast areas of the environment.”