In a recent study on reassessing the safety of nuclear power, the analysis has revealed six important conclusions about the risks of nuclear power as discussed by the authors of this article.
By Spencer Wheatley, Benjamin K. Sovacool, and Didier Sornette
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First,
concerning event frequency, our analysis shows that the rate of civil nuclear
accidents over time since 1952 decreased significantly from the 1970s, reaching
what appears to be a stable level of around 0.003 events per plant per year. In
this sense, nuclear power is getting safer, although this improvement could be
offset by the construction and operation of many new facilities. We find
concrete evidence of a history of learning from previous accidents within the
industry, especially the significant reduction in event frequency after the
Chernobyl accident in 1986, and a suppression of moderately large cost events
after TMI.
Second,
however, is that these past reforms, rather than minimizing risk, have
apparently spawned the prevalence of dragon kings and accidents with major
costs. Chernobyl and Fukushima are both such dragon kings, as they together
represent 84 percent of the total damage in our dataset. The morphology of
nuclear accident risk has altered from more frequent, less costly events to
less frequent, more costly events.
Third,
existing databases are woefully incomplete when it comes to the reporting of
nuclear incidents and accidents. For instance, only half of the events in our
database have INES scores, and thousands upon thousands of small events – but
with the potential to cascade into larger ones – remain unreported. As the
authors of concluded,
“many nuclear safety related events occur year after year, all over the world,
in all types of nuclear plants and in all reactor designs and that there are
very serious events that go either entirely unnoticed by the broader public or
remain significantly under-evaluated when it comes to their potential risk.” A
fully transparent, centralized source of reliable data on nuclear accidents is
needed; one that enables planners, investors, and even nuclear regulators to
better comprehend, and then weigh, nuclear risks. Such full disclosure will
need to be balanced with the legitimate security concerns of the nuclear
industry and the need to avoid promoting a culture of panic and hysteria.
Fourth, apart
from being incomplete, industry standard tools such as the INES scale of the
IAEA are inadequate and inconsistent at identifying and projecting nuclear
accident risk, especially related to dragon kings. For the costs to be
consistent with the INES scores, the Fukushima disaster would need to be
between an INES level of 10 and 11, rather than the maximum level of 7. To use
an analogy, the INES scale is like the antiquated Mercalli scale for earthquake
magnitudes, which was replaced by the continuous physically-based Richter
scale. Instead of INES, we recommend the use of continuous scales genuinely
based on relevant physical variables (radiation emission as in NAMS) and/or
economic metrics (dollar costs as proposed here) and that these scales be
publicly disclosed for as many events as possible, including all of those in
our database.
Fifth, we need
to better understand “near misses,” “false negatives,” “minor mishaps,” and
“residual risk”.Our study has focused only on “extreme risk,” that is, accidents that
precipitated at least $20 million in damages, but an entire class of narrow
escapes exist, unplanned or unanticipated events and warnings that never
resulted in damage and In the European Union, for example, legislation called the Seveso directive has
emphasized, since 1982, the importance of near-misses for hazardous accidents
on land, especially in the oil and gas industry. A similar directive ought to
be considered for the nuclear industry, and it requires a complete data set of
both small and large events to properly quantify the frequency with which small
events escalate into larger ones.
Sixth, future
frequency and severity of accidents are perhaps unacceptably high. While the
nuclear industry can be characterized by an impressive improvement in incident
prevention and safety procedures, our thorough analysis of this new data shows
that, when a nuclear event of at least $20 million in damage occurs, the
probability that it transforms into a catastrophe with damage larger than one
billion dollars is almost ten percent. Under the status quo, we project at
least one Fukushima-scale dragon king (or larger) accident with 50% probability
every 60–150 years. And, more common but still expensive events of about $20
million will occur with a frequency of about one per year—making accidents a
relatively routine part of nuclear power’s future.
In conclusion,
although the frequency of events per reactor has become less common, the
relative frequency with which events cascade into “dragon king” extremes is
large enough that, when multiplied by severity, the aggregate risk to society
is still very high. To effectively reduce this risk, the possibility of
Chernobyl and Fukushima sized events needs to be better anticipated and then
more effectively managed.
About the Authors:
Spencer Wheatley -
Benjamin K. Sovacool - Department of Business and Technology, Aarhus University, Birk Centerpark 15, DK-7400 Herning, Denmark and Science Policy Research Unit, University of Sussex, United Kingdom
Didier Sornette - ETH Zurich, Department of Management, Technology and Economics, Switzerland
Science Policy Research Unit, University of Sussex, United Kingdom
Publication Details:
This article is an excerpt from a technical paper, titled - "Reassessing the safety of nuclear
power" published at Energy
Research & Social Science, Volume 15, May
2016, Pages 96–100, doi:10.1016/j.erss.2015.12.026, Under a Creative Commons license