Publicatie Laka-bibliotheek:
Of Disasters and Dragon Kings: A Statistical Analysis of Nuclear Power Incidents & Accidents

AuteurS.Wheatley, B.Sovacool, D.Sornette
Datumapril 2015

Uit de publicatie:

Of Disasters and Dragon Kings:
A Statistical Analysis of Nuclear Power Incidents & Accidents

Spencer Wheatley1, Benjamin Sovacool2 and Didier Sornette1
1 ETH Zurich, Department of Management, Technology and Economics, Switzerland
2 Center for Energy Technologies and Department of Business and Technology, 
Aarhus University, Denmark
e-mails:, and
April 10, 2015

We provide, and perform a risk theoretic statistical analysis of, a dataset 
that is 75 percent larger than the previous best dataset on nuclear incidents 
and accidents, comparing the three measures of severity: INES (International 
Nuclear Event Scale), NAMS (Nuclear Accident Magnitude Scale) and dollar 
losses. The rate of nuclear accidents with damage above 20 MM 2013 USD 
(normalized by the number of reactors in operation) has decreased from the 
1970s until the present time. Along the way, the rate dropped significantly 
after Chernobyl (April, 1986) and is expected to be roughly stable around a 
current level (in 2015) of 0.002 to 0.003 events per plant per year. The 
distribution of damage sizes appears to have undergone a regime change shortly 
after the Three Mile Island major accident (March, 1979). The median damage 
size became approximately 3.5 times smaller, but the tail became much heavier, 
such that it is well described by a Pareto distribution with parameter α
  0.55. In fact, the damage of the largest event (Fukushima, 11 March, 2011) 
 is equal to near 60 percent of the total damage of all 174 accidents in our 
 database since 1946. We also document a statistically significant runaway 
 disaster regime in NAMS (radiation release) data as well as a related runaway 
 disaster regime in damage sizes, which we associate with the “dragonking” 
 phenomenon. With the current model and in terms of dollar losses, there is a 
 50% chance that (i) a Fukushima event (or larger) occurs in the next 50 years, 
 (ii) a Chernobyl event (or larger) occurs in the next 27 years and (iii) a TMI 
 event (or larger) occurs in the next 10 years. Further, smaller but still 
 expensive ( 20 MM 2013 USD) incidents will occur with a frequency of about 
 one per year. Finally, we find that the INES scale is inconsistent in terms of 
 both damage and NAMS (radiation release) values. For the damage values to be 
 consistent, the Fukushima disaster would need to be between an INES level of 
 10 and 11, rather than the maximum level of 7.