1

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.

2

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

3

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.

6

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.

13

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.

20

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.

22

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

23

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

24

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

25

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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