Post on 17-Sep-2018
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The Politics of Disaster Preparedness: Japan’s Nuclear Plant
Vulnerability in Comparative Perspective
Phillip Lipscy* and Kenji E. Kushida**
Prepared for CISAC Conference: “Learning from Fukushima: Improving Nuclear Safety and
Security after Accidents”
10/15/2012
* Phillip Y. Lipscy is Assistant Professor of Political Science and the Thomas Rohlen Center
Fellow at the Shorenstein Asia-Pacific Research Center, Stanford University
** Kenji E. Kushida is the Takahashi Research Associate in Japanese Studies at the Walter H.
Shorenstein Asia-Pacific Research Center, Stanford University.
The authors wish to thank Trevor Incerti for his excellent research assistance.
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Introduction
Most existing analyses of the 3/11 Fukushima Daiichi nuclear disaster have focused on
country-level failures, such as Japan's nuclear regulatory structures,1 insufficient disaster
preparedness at both organizational and technical levels,2 and even culture.
3 While many
organizational and technical failings did become manifestly obvious as the crisis unfolded,4
there are considerable reasons to question Japan-specific explanations for the deeper causes of
the crisis.
First, there is within-country variation in Japan. Four nuclear power plants along Japan’s
Northeast coast were hit by the tsunami, but the level of preparation—and therefore damage—
differed markedly across plants. While the Fukushima Daiichi Plant was a level 7 on the INES
(International Nuclear Event Scale), Fukushima Daini was level 3, Onagawa was level 1, and
Tokai Daini was not assigned an INES number.5 The Onagawa plant in particular experienced a
stronger seismic impact than Fukushima Daiichi, along with a tsunami of roughly equivalent
1 Masahiko Aoki and Geoffrey Rothwell, "A Comparative Industrial Organization Analysis of the
Fukushima Nuclear Disaster: Lessons and Policy Implications," (Stanford University, 2012); "Fukushima
Genpatsu jiko dokuritsu kenshou iinkai chosa/kenshou houkokusho [Fukushima Nuclear Accident
Independent Investigation Commission Research and Evaluation Report]," (Tokyo, Japan: Independent
Investigation Commission on the Fukushima Daiichi Nuclear Accident, 2012); National Diet of Japan,
"The Official Report of The Fukushima Nuclear Accident Independent Investigation Commission,"
(2012), http://naiic.go.jp; Investigation Committee on the Accident at Fukushima Nuclear Power Stations
of Tokyo Electric Power Company, "Final Report: Investigation Committee on the Accident at
Fukushima Nuclear Power Stations of Tokyo Electric Power Company," (2012), http://icanps.go.jp. 2 Edward D. Blandford and Joonhong Ahn, "Examining the Nuclear Accident at Fukushima Daiichi,"
Elements 8, no. 3 (2012); Charles Miller et al., "Recommendations for Enhancing Reactor Safety in the
21st Century: The Near-Term Task Force Review of Insights from the Fukushima Dai-Ichi Accident,"
(United States Nuclear Regulatory Commission). 3 Kiyoshi Kurokawa, "Message from the Chairman," ed. National Diet of Japan, The Official Report of
The Fukushima Nuclear Accident Independent Investigation Commission (Tokyo2012). 4 For a detailed overview of Fukushima Daiichi, see Kenji E. Kushida, "Japan's Fukushima Nuclear
Disaster: Narrative, Analysis, and Recommendations," Shorenstein APARC Working Paper Series, no.
June (2012), http://iis-db.stanford.edu/pubs/23762/2012Jun26_FukushimaReport_draft.pdf. 5 The INES scale is a logarithmic, self-reported scale. Level 7, the maximum, indicates a major accident.
Level 3 is a serious incident, and level 1 is an anomaly. For details, see http://www-ns.iaea.org/tech-
areas/emergency/ines.asp
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height, but experienced much less serious damage. Second, without conducting international
comparisons, it cannot be established that Japan's nuclear plants were particularly ill-prepared for
a tsunami disaster.
The question, put bluntly, is whether Japan was uniquely unprepared, or whether it had
the bad luck of being the first country to have a nuclear power plant overwhelmed by an
earthquake and tsunami. The nature of the Fukushima disaster lends itself to a comparative,
quantitative approach that was not possible for prior disasters such as Chernobyl and Three Mile
Island, which were triggered by human and technical failures. The Tohoku Earthquake and
Tsunami affected several nuclear plants simultaneously, offering a natural experiment in disaster
preparedness. In addition, although disaster response in Japan had many failings, we will show
that three variables were crucial at the initial stage of the crisis: plant elevation, sea wall
elevation, and location and status of backup generators. If the Fukushima Daiichi plant had
maintained higher elevations for any of these three variables, or if the backup generators had
been watertight, the disaster would likely have been much less serious. This observation allows
us to perform a much broader comparative study of disaster preparedness based on the status of
these three variables – assessed against plausible tsunami risk – for not only all nuclear plants in
Japan, but all seaside nuclear power plants in the world.
The ultimate goal of this research project is to determine what we can learn about politics
and regulation of disaster preparedness by looking across cases within Japan and across countries.
As a first step, we use data from all nuclear power plants within and outside of Japan that lie next
to the ocean, putting the Fukushima disaster in international context through a comparative
approach. We should emphasize that all results presented here are preliminary.
4
This paper unfolds in two parts. Part I is a within-country comparison of the four nuclear
power plants along the Northeastern Japanese seaboard hit by the same earthquake and tsunami.
Comparing the damage among them, it is clear that securing external electric power and on-site
backup electric power sources were critical. External power sources were compromised due to
the earthquake, while backup power sources were damaged by the tsunami. Since the reactors
losing both external and backup power incurred meltdowns, we derive from Part I a focus on
tsunami risk and preparedness of backup power sources within Japan and across countries.
Part II presents preliminary analysis of a dataset on tsunami risk and preparedness of
nuclear power plants around the world. The data includes information on 89 nuclear power
plants in 20 countries, collected from publicly available sources as well as directly from plant
operators. Using this data, we provide a cross-national comparison of tsunami disaster
preparedness at the time of the Tohoku Earthquake, focusing on plant elevation, sea wall height,
and generator status and elevation assessed against tsunami risk. Our results indicate that Japan
was relatively unprepared for a tsunami disaster in international comparison, but there was
considerable variation within Japan, and Japan was not the only country that was unprepared.
Our data also produces several novel findings about disaster preparedness in Japan. Within Japan,
plants constructed earlier, irrespective of subsequent improvements, exhibited inferior
preparedness. In addition, plants owned by the largest utility companies exhibited particularly
inadequate disaster preparations, while those owned by smaller utility companies were in line
with the international average. Although our results are preliminary at this stage, they point to
selective regulatory capture, in which the largest power companies in Japan were able to secure
relatively lax regulatory oversight compared to their domestic peers.
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Part I. Japanese Plants Hit by the Disaster: Identifying Key Variables
The tsunami that hit Northeastern Japan offers a natural experiment in disaster
preparedness. Four plants were simultaneously hit by the earthquake and tsunami. The four
plants were Fukushima Daiichi, Fukushima Daini, Onagawa, and Tokai Daini plants (see map in
Introduction). While it is well known that Fukushima Daiichi was declared an INES Level 7
event, Fukushima Daini was declared Level 3, and Onagawa a Level 1 event. As we will
illustrate, Fukushima Daiichi and Onagawa encountered almost identical seismic and tsunami
hazards with a wide disparity in outcomes, while the hazards for Fukushima Daini and Tokai
were somewhat less serious.
Comparing Damage Across the Japanese Plants
A comparison across the four reactors hit by the tsunami reveals the critical importance
of procuring electricity, either from external or backup sources. The plants required pumps to
cool the reactors, and these pumps required electricity. (In some cases, backup electricity
generators required cooling pumps as well.)
In the simplest comparison, the plants and reactors in which either external or backup
sources of power were operational survived without core meltdowns. Those that lost both—
Fukushima Daiichi reactors one through three, suffered meltdowns. External power sources
comprised of the power lines from the plant to the external electricity grid, along with the
transformer facilities. Backup power sources included emergency diesel generators, batteries,
generator trucks, and the transmission/transformer facilities. Table 1 shows the external and
backup power situation after the earthquake and tsunami hit, along with the INES disaster level.
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Table 1. Damage and INS Level of Four Japanese Nuclear Power Plants Hit by Earthquake and
Tsunami
External
Power?
Backup
power?
INES
Level
Disaster Outcome*
Fukushima
Daiichi
Reactors 1-4 X X
7
Core meltdown (1-3)
hydrogen explosion
Reactors 5, 6 X Cold shutdown
Fukushima Daini Reactors 1-4 3 Cold shutdown
Onagawa Reactors 1-3 O 1 Cold shutdown
Tōkai Daini Reactor X O 0 Cold shutdown
X= complete failure
= partial failure with at least one functional
O = majority intact
* note: focuses on nuclear reactors only: plants incurred extensive damage, including flooding,
cooling pump failures, fires, and loss of life of operator personnel to different degrees.
External power loss was primarily caused by the earthquake, which knocked down power
lines and destroyed conversion facilities. In fact, while Fukushima Daiichi and Tokai lost all
external power sources, those of Fukushima Daini and Onagawa barely survived, losing three out
of four, and four out of five lines, respectively; only one line remained in Fukushima Daini and
Onagawa. In Fukushima Daini in particular, external power was critical for operating the limited
number of backup power sources available.6
The tsunami was primarily responsible for the failure of backup power sources. The
tsunami not only directly damaged some of the backup power sources such as diesel generators
and batteries through flooding and debris, but also knocked out many of the seawater pumps
required to cool the diesel generators, rendering them inoperable. Only a few diesel generators
were air-cooled, and in some cases, such as Fukushima Dai-Ichi Reactor 6, these were only types
that survived.
6 Ohmae 2012
7
Fukushima Daiichi lost 12 of the 13 backup diesel generators. As a result, reactors 1, 2, 3
(in operation at the time of the earthquake), and 4 (out of out of operation, but with a large used
fuel pool) were unable to be cooled, leading to the disaster.7 The one functional generator in the
plant was able to cool reactors 5 and 6, enabling them to avoid the fates of the other reactors.
In the Fukushima Daini plant, three out of the twelve generators survived the tsunami,
enabling reactors 3 and 4 to be cooled until external power was rerouted. (Reactors 1 and 2 were
saved by temporary cables connecting to external power).
In Onagawa, 6 out of 8 diesel generators were intact, enabling the emergency cooling
system to be started. Moreover, since the cooling pumps themselves were largely intact, the
reactors were successfully brought to a cool state in the late evening of March 12.
In Tokai Daini, two out of three diesel generators survived, allowing the reactor to be
cooled until external power was restored on March 13, two days after the earthquake and tsunami.
Table 2 shows the total number of functional external power lines after the earthquake
compared to the number available, and the total number of functional backup diesel generators
after the tsunami. While other sources of emergency backup power, such as batteries and
electricity trucks also survived to varying degrees, for simplicity here we focus on backup diesel
generators.
7 The backup electricity truck connecting to reactor 2 was also damaged with the explosion of reactor 1.
8
Table 2. Surviving External Power Lines and Backup Diesel Generators at 4 Japanese Plants Hit
by Earthquake and Tsunami
Ground
Acceleration
Distance
From
Epicenter
Surviving External
Power Lines
(Earthquake
damage)
Surviving
Backup Diesel
Generators
(Tsunami
damage)
INES
Level
Fukushima
Daiichi
550 Gal 180km 0/6 1/13 7
Fukushima
Daini
305 Gal 190km 1/4 3/12 3
Onagawa 607 Gal 70km 1/5 6/8 1
Tōkai 214 Gal 280km 0/3 2/3 0
Securing external power sources in the face of potential disasters is clearly a critical issue.
Yet, given the possibilities of tornados, terrorism, or major natural disasters such as the March 11
earthquake, to sever external power lines, the security of backup power sources are of paramount
importance. The Tokai Daini reactor is the clearest example of this, having incurred a complete
loss of external power, but safely bringing the reactor to a cold shutdown by utilizing its
surviving backup power sources. The Higashi Dori nuclear power plant in Aomori Prefecture
also lost all external power in the magnitude 7.1 aftershock on April 7, 2011. The backup diesel
generators were operational, however, and it did not develop into a serious incident.
A simple comparison of the plants hit by the tsunami show a notable divergence in the
degree of preparation against tsunami damage in terms of plant height or sea wall height. Table 3
compares the recorded tsunami height at each plant to the sea wall height, plant height.
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Table 3. Tsunami Height Compared with Nuclear Power Plant/Sea Wall Height
Power Station Tsunami
Height
Sea
Wall
Height
Plant Height
Above Sea
Level
Greater of Sea
Wall and Plant
Height
Fukushima
Daiichi
13m 10m 10m 10m
Fukushima
Daini
9m 9m 12m 12m
Onagawa 13m 14m 13.8m 14m
Tōkai Daini 4.6m 6.1m 8m 8m
It is clear that the Onagawa power plant was adequately prepared, with a sea wall height
of 14 meters in the face of a 13 meter tsunami. The 13 meter tsunami in Fukushima Dai-Ichi
overwhelmed the 10 meter high sea wall, and the 9 meter tsunami flooded part of the Fukushima
Daini plant. The experience of Tokai Daini revealed that quality was important as well, since
retrofitting construction led to the sea wall not being completely water tight, resulting in flooding
and the loss of one backup generator despite the 4.6 meter tsunami being lower than the 6.1
meter sea wall.
From this comparison of within-Japan variation of power plants hit by the March 11,
2011 earthquake and tsunami, it is clear that three variables were critical in contributing to the
initial stages of the nuclear catastrophe at Fukushima: 1. Nuclear power plant elevation; 2.
Elevation of sea walls; 3. The status and location of backup power sources. In the next section,
we examine these three variables across a wider range of nuclear power plants to place the
Fukushima disaster in comparative perspective.
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Part II. Data and Analysis : Tsunami Risk and Preparedness
Variables and Methodology
To assess comparative levels of tsunami preparedness at global coastal nuclear power
stations (NPSs), we collected data for the following variables: base plant elevation, seawall
height, emergency power system elevation, waterproofing of backup power systems, commission
date, reactor type, maximum water height, and Soloviev-Imamura tsunami intensity. Since our
goal is to compare disaster preparedness at the time of the Tohoku Earthquake, all data refers to
NPS infrastructure as it existed prior to March 11, 2011. Any additional safety features
introduced following the Fukushima Daiichi disaster are not included in our analysis.
Base plant elevation is a measure of the height of critical components of the NPS above
mean sea level. As seen in the previous section, elevation above sea level is a primary
determinant of an NPS’s risk of tsunami inundation. We typically measured elevation at the base
of the reactor building. However, where components deemed critical for reactor operation or safe
shutdown are located at elevations lower than the reactor building, the lower elevation is
recorded. Primary sources for elevation data include national nuclear regulatory agencies, the
International Atomic Energy Agency (IAEA), European “stress tests” conducted in response to
the Fukushima disaster, and primary source information from nuclear plant operators.
Seawall height is similarly recorded as the maximum height of a seawall, flood barrier,
levy, or natural barrier (such as sand dunes or barrier islands) above mean sea level. Such
barriers possess the ability to halt or mitigate the effects of a tsunami prior to impact with an
NPS. In the event that a plant does not posses a seawall or other barrier, or the barrier in question
is not designed for protection against tsunami or storm surge, the height is recorded as zero.
Sources are identical to base plant elevation.
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Emergency power system elevation is a measure of the elevation of critical backup
power supply systems above mean sea level. These systems include emergency diesel generators,
gas turbine-driven generators, and battery systems. Data sources for emergency power system
location include national nuclear regulatory agencies, the IAEA, European “stress tests,” and
interviews with plant operators. However, in some cases, we found that this information is not
publically available on national security grounds.
Because emergency power system preparedness is determined by flood protection in
addition to elevation, waterproofing of emergency power supplies is also noted. Specifically,
this is an assessment of whether emergency power systems are located behind flood proof doors
or in watertight bunkers. The same assessment is made of diesel fuel storage tanks. This is
recorded as a dichotomous variable (1 for yes, 0 for no). Sources are identical to base plant
elevation and seawall height, with greater relative reliance on information collected directly from
power operators and regulators.
Construction and Commission dates refer to the dates construction was initiated and
the reactor became commercially operational. Where reactors have been decommissioned or are
currently undergoing decommissioning, the decommissioning date is also noted.
Reactor type refers to classification of the NPS’s reactor(s) by type of nuclear reaction,
moderator material, coolant, and use. Reported coastal reactors consist of boiling water reactors
(BWR), heavy-water-moderated boiling light water cooled reactors (HWLWR), fast-breeder
reactors (FBR), gas cooled reactors (GCR), light water graphite reactors (LWGR), pressurized
water reactors (PWR), and pressurized heavy water reactors (PHWR/CANDU). Construction,
decommissioning, and reactor type information was provided by the IAEA.
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Maximum water height is a measurement of the maximum historically reported water or
wave height recorded within a 150km radius of an NPS. Of course, local geography may
magnify the height of a wave such that a “nearby” estimate is not appropriate for the particular
location of the plant. Likewise, local geography at the plant site may mitigate the effects of a
tsunami. The primary sources of historical tsunami data are the National Geophysical Data
Center (NGDC) Global Historical Tsunami Database and the Russian Academy of Sciences
(RAS) Novosibirsk Tsunami Laboratory Historical Tsunami Database. Where possible,
independent regionally focused government and academic reports were also consulted for
confirmation (Dunbar 2008, Gill 2005, Grossi 2011, Haslett and Bryant 2006, 2008, Kim et al.
2011, Lau et al. 2010, Lim et al. 2007, Liu et al. 2007, Lockridge et al. 2002, Minoura et al. 2001,
Papadopoulos and Fokaefs 2005, Roger and Gunell 2012, Shahid 2004, Shibata 2012, Smith et al.
1988, 2004). As the Tohoku Earthquake is considered a 1000-year event (an event occurring
with a frequency of approximately once every thousand years),8 we do not restrict the historical
date range for past events.
Several observations about this variable are in order. Historical data is more readily
available for certain geographical regions. Importantly, historical wave height data for the United
States is not available prior to post-European settlement – the measure therefore likely
understates tsunami hazard risk for North and South America compared to other regions of the
world. Additionally, maximum water height is not always associated with earthquakes.
Landslides are also a common source of large waves. In the eastern United States, waves
generated by hurricane-induced storm surges typically reach heights greater than those caused by
seismic events.
8 Nyquist, Christina, “The March 11 Tohoku Earthquake, One Year Later. What Have We Learned,” U.S. Geological Survey Science Features 2012-3-9.
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The Soloviev-Imamura (S-I) tsunami intensity scale is another measure used to assess
the relative strength of historical, nearby tsunamis. This is calculated according to the formula
I = ½ + log2 Hav,
Where Hav is the average wave height along the nearest coast. As the S-I intensity is calculated
from average wave height, rather than maximum, it is less likely to be influenced by extreme
outliers induced by local geographic conditions. We record the highest S-I intensity associated
with a 150km radius around the NPS. All S-I intensity data was collected from the NGDC and
RAS tsunami databases.
Part II. International Comparisons of Disaster Preparedness
In this section, we use our dataset to draw comparisons for disaster preparedness across
all nuclear plants currently in operation in the world. We begin by considering absolute
measures of tsunami preparedness, and move to measures that adjust for tsunami hazard risk.
Figure 1 plots the maximum of plant and sea wall height for nuclear plants across the
world, separated by country. This is perhaps the most simple indicator for how well a plant
would be able to withstand a major tsunami – higher elevation and sea wall protection make it
less likely that a plant will be inundated. As the figure shows, there is considerable cross-
national variation in this measure. Particularly low-lying plants are found in Nordic states, such
as Finland and Sweden, presumably because tsunami hazard risk is considered negligible.
However, there is also considerable variation within countries, such as France, Japan, the UK,
and USA. According to this measure, Japan does not look particularly vulnerable in comparison
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to its international peers. On average, Japanese plants are located about 10.1m above sea level
and are protected by sea wall averaging 4.6m in height. International averages are 8.8m for plant
height and 3.5m for sea wall height.
Figure 1: Maximum of Plant and Sea Wall Height (m), International Comparison
Although this measure does not account for tsunami risk, it should not be dismissed
outright for several reasons. It is not uncommon for tsunamis or major ocean surges to occur in
regions of the world with limited seismic activity, for reasons such as hurricanes, landslides, and
meteorite impacts. In addition, existing data on tsunami risk relies on written records to identify
historical episodes, and such records are oftentimes spotty or imprecise. For example, NOAA
data on historical tsunamis goes back to the year 123 for China and 684 for Japan, but only to
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1668 for the East Coast of the United States.9 The closest precedent to the Tohoku Earthquake is
considered to be the 869 Jogan Earthquake. For this reason, tsunami risk is likely to be
understated for regions of the world where written records are limited, most notably North and
South America. Based on these factors, the data raises questions about the adequacy of tsunami
preparedness in Finland, Sweden, and the United States, countries with relatively low-lying
nuclear plants and sea walls.
We now move to an analysis of preparedness accounting for tsunami risk. We consider
two principal measures of tsunami risk. The first is the highest recorded wave run up within a
150km radius. Figure 2 plots this measure against the maximum of plant and sea wall height.
Japanese plants are depicted with triangles, while other international plants are depicted with
circles. Plants lying below the diagonal line are those where a historical tsunami was measured
exceeding both sea wall and tsunami height. The figure shows that a large number of Japanese
plants lie below the line. This is primarily attributable to the fact that Japan has recorded
particularly high tsunamis in the past – of the seven plants in our data set that lie in regions
where tsunami height has exceeded 20m, six lie in Japan (the sole exception is the Maanshan
plant in Taiwan). It is worth noting, however, that many Japanese plants are above the line, and
many plants outside of Japan are below the line. The following countries were also found to
have nuclear plants with inadequate protections based on this measure: Pakistan, Taiwan, the UK,
and the United States.
This finding is particularly problematic for the United States, for which historical data is
likely to understate tsunami risk as discussed above. Tsunami data for South Asia, East Asia,
and Northern Europe is available for a much longer period, about two thousand years, compared
9 Data is available here: http://www.ngdc.noaa.gov/hazard/tsu_db.shtml
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to only about four hundred years for the United States. The highest recorded tsunami for several
plants in Japan are quite old – 1026 for the Shimane plant and 1341 for the Higashi Dori plant.
Any tsunamis occurring during this earlier time period remain unknown and cannot be reflected
in the calculations for the United States.
Figure 2: Maximum of Plant or Seawall Height vs. Maximum Water Height
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Figure3: Emergency Power System Elevation vs. Maximum Water Height
Figure 3 similarly plots maximum historical tsunami height against the elevation of on-
site emergency power systems. This is one area where disaster preparedness in Japan appears to
clearly stand out as being relatively inadequate in international comparison. Aside from
Pakistan’s Karachi plant, all emergency power systems lying below the diagonal line are
associated with Japanese plants. This indicates that Japanese nuclear plants were not only
vulnerable to being inundated by a tsunami, but also to losing backup power in the event of
inundation. We should caution, however, that data availability is less comprehensive for this
measure, as several plant operators, particularly in the United States, refused to provide us with
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information on the elevation of backup generators, citing security concerns. It is therefore
possible that the figure overstates the adequacy of disaster preparation outside of Japan, where
we were able to obtain comprehensive data.
A second measure of tsunami risk we consider is the S-I index. Since the S-I index is not
directly comparable to plant and sea wall height, we calculate Hav – the average wave height
along the nearest coast – from the underlying formula, and compare this to plant and sea wall
height. More specifically, the measure we use is what we call the “Hav Ratio,” calculated as Hav /
maximum of plant and sea wall height. Any number above one for this ratio indicates that, for a
given plant, average wave height implied by the S-I index exceeds the maximum of plant and sea
wall height. Since the S-I index is based on average, rather than maximum wave height, ratios
close to one should also be considered indicative of potentially inadequate disaster preparedness.
Figure 4 plots this ratio for each plant in our dataset, separated by country. The ratio for
Fukushima Daiichi was 1.13. The figure indicates that the Fukushima Daiichi plant was
relatively inadequately prepared in international comparison, but not singularly so. There are
many plants that fall within a similar range, and seven plants that exceed one, all located in Japan
and the United States.
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Figure 4: Hav Ratio over Time, All Plants by Country
Note: High numbers imply inadequate disaster preparation (i.e. high tsunami risk and low
elevation of plant and sea wall. A number above one means the plant and sea wall both lie below
the average wave height of a historical incident.
Figure 5 reorganizes the data from the previous chart in time series format, with plants
sorted by the year of construction. It is interesting to note that all plants with a Hav ratio
exceeding or very close to one where constructed prior to the early 1980s. However, there does
not appear to be any clear trend in Hav ratios over time – both the earliest and most recent plants
tend to have low ratios.
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Figure 5: Hav Ratio over Time, All Plants by Date of Construction
The picture is somewhat different when we consider plants within Japan. Figure 6 plots
the Hav ratio over time for Japanese nuclear plants by year of construction. The figure shows a
clear downward trend, with early plants exhibiting higher ratios than more recent plants.
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Figure 6 : Hav Ratio over Time, Japanese Plants by Date of Construction
This primarily reflects the fact that nuclear plants constructed earlier on in Japan tended
to be inadequately protected. Figures 7 plots the S-I Index for Japanese plants over time.
Although there is a slight downward trajectory, indicating earlier plants on average were
constructed in more hazardous areas, most of this variation is due to two recent plants. On the
other hand, as Figure 8 shows, the maximum of plant and sea wall height exhibits a clearer
upward trajectory.
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Figure 7: S-I Intensity, Japanese Plants by Date of Construction
Figure 8: Maximum of Plant and Sea Wall Height, Japanese Plants by Date of
Construction
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Figure 9: Hav Ratio by Plant Operator, Japan
We finally consider Hav Ratios by plant operator in Japan. It is interesting to note that the
three largest utility companies of Japan, TEPCO, KEPCO, Chubu, tend to have relatively
elevated Hav Ratios, i.e. plants more vulnerable to plausible tsunami risk, compared to their more
regional counterparts. Along with JAPCO – a utility dedicated to nuclear power and 60%
controlled by TEPCO, KEPCO, and Chubu – these companies own all nuclear plants in Japan
with Hav Ratios above one, which is indicative of serious deficiencies in disaster preparedness.
These companies also tended to be the earliest builder of nuclear plants in Japan. A simple linear
regression, shown in Table 4, suggests that early date of construction and ownership by a large
utility company are both associated high risk as indicated by the Hav Ratio. The second column
of Table 4 calculates an alternative Hav Ratio based on the elevation of backup generators,
another important indicator of preparedness. As the table shows, large utilities are associated
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with low lying generators in comparison to tsunami risk. For generator elevation, there is no
meaningful relationship between plant construction date and the Hav Ratio.
Table 4: Hav Ratio for Japanese Power Plants and Large Utilities
Indep Vars/
Model
Specification
Hav Ratio
OLS
Hav Ratio
(Generator Elevation)
OLS
Construction
Year
-0.13*
(0.06)
-0.01
(0.01)
Large Utility
Dummy
0.52*
(0.15)
0.70*
(0.24)
n
19
19
Note: Large Utility dummy takes on value of 1 for TEPCO, KEPCO, Chubu, and JAPCO, and 0
otherwise.
These results suggest that inadequacies in Japan’s disaster preparedness were primarily
concentrated among the largest utilities. An international comparison underscores this point.
For nuclear plants operated by small utilities in Japan, the average Hav Ratio is 0.43, which is
indistinguishable from the international average, which is 0.41. In comparison, the Hav Ratio for
plants operated by TEPCO, KEPCO, Chubu, and JAPCO average 1.05, more than twice the
international average.
These results are strongly suggestive of an explanation based on regulatory capture. The
largest utility companies in Japan were also generally the most politically influential, offering
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lucrative retirement positions for retired bureaucrats, political contributions, and organized votes.
It is therefore plausible that these largest utility operators were able to push back against
government regulators to a degree not possible by smaller operators such as Kyushu or Shikoku
Electric. Although a large body of existing, qualitative research has found fault with TEPCO
(e.g. Carnegie Endowment for International Peace 2012), our methodology suggests that other
large utilities in Japan deserve equal scrutiny.
We also consider whether such regulatory capture may also be a factor at the
international level. Table 5 presents results from a similar regression that includes all seaside
nuclear power plants in the world. As a proxy for the size, and hence potential political
influence of utility companies, we use the log of revenues, measured in 2010 in US dollars. This
measure is more likely to be meaningful when comparing the political influence of utility
operators within countries rather than across countries – a dollar of revenue is unlikely to have
the same meaning in Pakistan as it does in Japan. Hence, we estimate the statistical models with
country fixed effects to account for heterogeneity across countries. The results show that, within
countries, larger utility companies tend to have weaker disaster preparedness compared to
smaller utility companies. This result holds up even when Japan is excluded from the analysis,
as the second column of Table 5 shows. On the other hand, construction year is not
meaningfully associated with preparedness. This suggests that the tendency for large operators
to be inadequately prepared is not limited to Japan. This point is worthy of further investigation
in future research.
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Table 5: Hav Ratio and Utility Revenues: All Seaside Plants in the World
Indep Vars/
Model
Specification
Hav Ratio
OLS
Hav Ratio
OLS
(Excluding Japan)
Construction
Year
-0.01
(0.01)
-0.00
(0.01)
Revenues
(log)
0.01*
(0.00)
0.02*
(0.01)
n
57
42
Note: All models include country fixed effects.
Civil Society
We also considered the potential role of civil society within Japan. Previous scholarship
has argued that civil society groups have played an important role in resisting the siting of “Not
in my backyard (NIMBY)” facilities such as nuclear power plants in nearby locations (Aldrich
2008). If so, it may also be the case that localities with strong civic organizations are able to
advocate for strong preparedness measures against natural disasters such as tsunami. We
therefore examine if the key civil society measures from Aldrich (2008) are associated with
adequacy of tsunami preparedness. We follow Aldrich’s proxies for the quality and quantity of
civil society. Civil society quality is measured as the population increase from 1950 through the
original siting attempt, on the logic that civil society associations tend to weaken when there is a
large influx of residents who are not familiar to the community. Civil society capacity is
27
measured as the change in percentage of population employed in the primary sector from 1980-
1995, on the logic that civic organizations likely to express the greatest concern over nuclear
facilities will be associated with agriculture and fisheries groups. These are crude proxies at best,
but they have been found to be correlated with successful attempts at resisting nuclear plans
sitings. Table 6 presents these results. As the table shows, there is essentially no relationship
between Aldrich’s civil society variables and tsunami disaster preparedness as measure by the
Hav ratio. Various other model specifications produced similar results. It may be that because
nuclear plants tend to be sited in areas where civil society is already weak, any residual variation
in civil society strength is not large enough to create pressure for greater preparedness. It may
also be that a relatively technical issue such as disaster preparedness is not as susceptible to
influence by civil society groups compared to an inherently political issue such as siting.
Table 6: Hav Ratio for Japanese Power Plants
Indep Vars/
Model
Specification
Hav Ratio
OLS
Hav Ratio
(Generator Elevation)
OLS
Civil Society
Quality
0.27
(0.24)
0.55
(0.45)
Civil Society
Capacity
-0.07
(0.40)
-0.20
(0.47)
n
19
19
Note: Civil Society Quality is measured as population increase from 1950 through the siting
attempt, and Civil Society Capacity is measured as change in percentage of population employed
in the primary sector from 1980-1995.
28
Political Factors and Cross-National Variation in Disaster Preparedness
We also examined several political factors that may correlate with the state of disaster
preparedness in a cross-national context. A large body of literature in political science suggests
that certain types of government institutions are more conducive to the provision of public goods.
In turn, adequate preparation against natural disasters can be thought of as a public good akin to
national defense or education –individual citizens do not have strong incentives to implement or
lobby for measures that increase disaster preparedness, but such measures produce diffuse
benefits for the population as a whole. Hence, we consider three measures that purportedly
correlate with the provision of public goods according to existing research – democracy, the size
of winning coalitions, and the effective number of political parties. In theory, democratic
governments are more responsive to the concerns of the general public and may be more
proactive about securing public safety compared to more authoritarian regimes. Indeed, cross-
national comparisons generally find that democracies tend to suffer less damage from natural
disasters than autocratic regimes (Kahn 2005). Bueno de Mesquite et al (2003) similarly argue
that the size of the winning coalition necessary to secure political power correlates with the
provision of public goods. Finally, some have argued that electoral systems characterized by
fewer political parties in each electoral district, such as majoritarian systems, are more likely to
generate public goods due to the fact that politicians cannot secure office by narrowly targeting a
small subset of constituents and must instead cater to broad public concerns (Bawn and Thies
2003).
We examined whether proxies for these variables show any association with better
disaster preparedness for coastal nuclear plants. The results are shown in Table 7. As
democracy and winning coalition size are highly correlated, we use separate models for those
29
two variables. As the results show, more democratic governments and larger winning coalitions
are associated with higher Hav Ratios, or less adequate preparation for tsunami disasters. This is
contrary to expectations about these types of governments being more mindful of public goods.
There is no meaningful relationship between our proxy for electoral incentives and disaster
preparedness.
Table 7: Hav Ratio and Political Institutions
Indep Vars/
Model Specification
Hav Ratio
OLS
Hav Ratio
OLS
Hav Ratio
(Generator
Elevation)
OLS
Hav Ratio
(Generator
Elevation)
OLS
Democracy
(Polity Score)
0.02*
(0.01)
0.04*
(0.02)
W (Size of
Winning Coalition)
0.52*
(0.14)
0.70*
(0.26)
Effective Number of
Political Parties
n
-0.02
(0.02)
81
-0.01
(0.02)
81
0.01
(0.02)
59
0.02
(0.03)
59
30
Discussion
These results present a mixed picture for Japan’s record on disaster preparedness.
According to our cross-national comparisons, it appears clear that Japan was inadequately
prepared relative to the tsunami risk it confronts. This can be attributed primarily to the fact that
Japan faces higher risks of tsunami compared to other countries due to frequent seismic activity.
Japan’s lack of preparedness particularly stands out with respect to the status of backup
generators, which were a crucial element in the meltdown of the Fukushima Daiichi plant.
However, several caveats are in order. First, not all Japanese plants were inadequately
prepared for a tsunami. The most vulnerable plants tended to be operated by the largest utility
companies and were constructed early on. Second, Japan’s lack of preparedness was not unique
– we identified several power plants outside of the country that were also characterized by
inadequate preparation relative to tsunami risk. Finally, in an absolute sense, plants outside of
Japan are on average less prepared for tsunami than those inside Japan. It is worth emphasizing
again that tsunami risk is likely understated in areas of the world where historical records are
limited, particularly North and South America. In this respect, the adequacy of preparation in the
United States is questionable at best – US plants are characterized generally by low levels of
protection against tsunami, and available data likely understates tsunami risk.
This study opens several avenues for future inquiry. First, given that Japan’s most high
risk plants were older plants, even after improvements such as heightening sea walls in the early
2000s, and that the largest operators were responsible for the highest risk plants regardless of the
timing of construction, this leads to questions of regulatory capture. Existing reports generally
contend that regulatory capture was a Japan-wide phenomenon. However, our results indicate
31
that smaller operators have built plants with consistently lower tsunami risk. This observation
has potential implications for policy debates within Japan over restructuring the industry, where
the possibility of breaking apart the regional electric power companies has been raised. Second,
this data suggests that the US, often considered a paragon for disaster preparedness, may harbor
significant risk factors that should be examined more closely, particularly given the short time
span of available historical data.
32
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