600977012
A Summary of
Accidents
Related to
Non-Nuclear Energy
United States Environmental Protection Agency
Office of Research and Development
Office of Energy, Minerals and Industry
May 1977
LIBRARY —'
U, S. ENvL- .. . - PRQiECliON AGENCY
N. J.
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Foreword
This report is based on a study of Accidents and Unscheduled Events Associated
with Non-Nuclear Energy Resources and Technology. The study was sponsored by
the Environmental Protection Agency under the guidance of Dr. Stephen J. Gage,
Deputy Assistant Administrator of the Office of Energy, Minerals, and Industry.
The study was performed in support of the Committee on Nuclear and Alternative
Energy Systems of the National Academy of Sciences. The Committee is studying
the energy future of the United States from 1980 to 2010 for the Energy Research
and Development Administration.
The Purpose of the study is to assist the American people and the legislative and
executive branches of government in formulation of an energy policy, by pointing
out the nature of the choices the nation may wish to keep available in the future and
by listing the actions and research and development programs that may be required
to do so.
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Table of Contents
Page
INTRODUCTION I
COAL 2
CRUDE OIL 3
NATURAL GAS AND LNG 5
HYDROELECTRIC AND OTHER ELECTRIC POWER 7
DEVELOPING ENERGY SYSTEMS 9
ADVERSE NATURAL AND OTHER INCIDENTS 11
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UPI PI
Norwegian f ireboat pours water on oil platform to contain a 4,000 ton-a-day oil spill in the North Sea. April, 1977 (UPI)
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Introduction
At present, various means of reducing U.S. depend-
ence on foreign energy sources have been investigated in
the United States. Most of the discussion has concerned
availability of various energy resources, availability and
cost of technology, and environmental effects.
Among those systems which have received much
attention is nuclear energy. Nuclear energy could supply
a significant part of the nation's electrical energy needs.
Safety concerns, however, have proven to be a major
impediment to the development of nuclear energy.
In order to choose intelligently among the energy
alternatives available, the safety of using non-nuclear
energy resources must be considered. Although some
hazards such as oil spills and coal mine explosions have
received significant attention from the public and the
regulatory agencies, no comprehensive assessment similar
to that performed for nuclear energy exists concerning
the safety of developing non-nuclear resources.
The first step in the assessment of the hazards of
non-nuclear systems is a compilation of existing accident
data. A report entitled Accidents and Unscheduled
Events Associated with Non-Nuclear Energy Resources
and Technology,1 has been prepared in an effort to sum-
marize available information on this subject. This paper
summarizes the findings of that report. Numbers in par-
entheses refer to sections and pages in reference 1. Acci-
dents or unscheduled events, whether natural or human-
made, are considered. However, emphasis is placed on
major accidents or minor accidents which have a cumula-
tive major effect.
The availability of accident data for analysis is greater
for well developed technologies such as oil, natural gas,
and coal than for those systems in the developmental
stage. Nevertheless, similarities between developing tech-
nologies and existing technologies and risk analysis
studies provide a basis for comparison. Energy systems
considered are coal, crude oil, natural gas, liquified na-
tural gas (LNG), hydroelectric, oil shale, geothermal, and
solar. Accidents in each energy cycle element (explora-
tion, extraction, processing, transportation including
transmission and distribution, and end use technologies)
are considered. Excluded from consideration in this re-
port are environmental effects or threats to human
health, safety, or property resulting from normal opera-
tions. Impacts of normal operations such as instances of
black lung disease in the coal mining industry must, of
course,. be considered in choosing among available
energy development options.
There are two major factors which make comparison
of the accident potential of energy systems difficult. The
first factor is the difference in the bases among systems
from which accident predictions are made. Historical
data provide the basis for established systems but for
newly developing systems risk analyses and modelling
must be performed to arrive at accident predictions. The
second factor is the lack of a consistent system of re-
porting accidents. However, based on the best available
estimate, there are probably a significantly greater num-
ber of deaths and injuries associated with the coal re-
source system per megawatt delivered than with the
crude oil or natural gas system. The annual deaths and
injuries associated with coal, oil, and gas fired electricity
systems for a 1000 megawatt power plant are shown in
Table I. Fatalities and injuries associated with the coal
industry are an order of magnitude greater than those
associated with the oil and natural gas industries.
TABLE 1
ANNUAL DEATHS AND INJURIES BY ENERGY SOURCE FOR
A 1000 MEGAWATT POWER PLANT WITH A LOAD FACTOR OF 0.75
(PER UNIT ENERGY)
Fatalities
Injuries
COAL
CRUDE OIL
DEEP
4.00
112.30
SURFACE
2.64
41.20
ONSHORE
0.35
32.30
OFFSHORE
0.35
32.30
NATURAL GAS
IMPORT
0.06
5.70
TOTAL
0.20
18.30
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Coal
Summary
Underground coal mining is more dangerous than
surface mining with an injury frequency rate four
times greater than surface coal mining.
Most people would identify fires and explosions
as the most severe mining disasters. This is largely
due to the sensational nature of such events and
extensive news media coverage. In fact, fires and
explosions account for only 10-12% of the annual
fatalities. The majority of fatalities (50%) are
caused by roof, rib, and face falls in underground
mines.
In the developing technologies such as coal gasi-
fication and liquefaction systems, safety aspects
must be considered in order to make intelligent
decisions as to which technologies could most
safely provide the needed energy. However, no
historical data are available for these new tech-
nologies and extrapolations of accident rates can
only be made from similar existing technologies.
TABLE II
COAL MINING ACCIDENT RATES
Disabling Injuries/
Million Employee-Hours
Underground Coal Mining
Surface Coal Mining
Overall Industry Average (All
member companies of National
Safety Council)
35.0
10.0
9.8
Historically, coal mining has been a dangerous occu-
pation. The threat to personal safety depends upon the
extraction technique, location of the mine, the activity
and location of the miner, experience of the mining
crew, and equipment used. However, statistics show that
underground coal mining is more hazardous than surface
mining (Sec. 3.2.2, p. 46). National Safety Council data
confirming this are presented in Table II. The per-
centage and kinds of accidents occurring in coal mining
are presented in Table III.
Although fires and explosions are often emphasized
by the news media, only 10-12% of the annual mining
fatalities are attributable to these causes. Also, due to
better safety regulations the number of miners killed
annually in mine explosions has been steadily decreasing
(Sec. 3.2.2 p. 58). Roof, rib and face falls account for
the majority of accidents (50%). Surface mining acci-
dents are approximately equally divided among fall of
highwall, haulage truck operations, front-end loader
operations, and electrical system malfunctions. Re-
cently, there has been increased concern about the dan-
ger presented, by detonation of charges, to the surround-
ing population. These people may experience reverbera-
tions and possible home damage.
Transportation accidents account for 10-15% of
mining fatalities. In underground mining operations,
hauling is the most dangerous function. Although such
accidents are not frequent, they are severe. Coal is trans-
ported to the consumer via rail, trucks and slurry pipe-
lines. These three rank from most to least dangerous in
terms of fatal injuries per 10!2 BTU* equivalent tons
shipped as follows: railroads are most dangerous at 0.06
followed by trucks at 0.032 and slurry pipeline at
0.00191 (Sec. 3.2.4 p. 64).
Remaining accidents involve processing/beneficiation
and reclamation operations including subsidence of
underground mines and collapse or combustion of refuse
piles used as dams (Sec. 3.2.5 p. 66).
*This amount of energy is equal to that required to run
a 1000 MW power plant for approximately 300 hrs, or to
that needed to heat approximately 5000 homes for one
season (October through April) in a temperate climate.
TABLE III
TYPES OF COAL MINING ACCIDENTS
Accident Percentage (%)
Underground (total) 80
Roof, rib, and face falls 50
Fires and explosions 10-12
Transportation (coal haulage) 10-15
Surface (total) 20
(Fall of highwall, equipment
misoperation, electrical system
malfunctions)
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Crude Oil
Summary
Oil spills are the most frequent accident. Seventy-
five percent of human-related spills come from
vessels. However, of the total amount released,
fifty percent comes from uncontrollable non-
point sources.
The release of oil itself does not constitute an
immediate hazard to human life. The greatest
damage is to ecological systems. This damage
may not be permanent, and many areas that have
suffered from an oil spill appear to have recovered
within three to four years. However, longer term
ecological disruptions also have been observed.
Transportation of oil via tankers accounts for a
greater number of fatalities and injuries annually
than transportation of oil via pipeline. Pipeline
accidents number approximately 135 per year,
and cause approximately one fatality and one
injury per year. Tanker accidents number approxi-
mately 640 per year and cause approximately 75
fatalities and 35 injuries per year.
Tanker spill rate does not appear to depend upon
size of tanker or age of tanker, but mainly upon
the number of voyages.
The relative merits of developing offshore oil and
gas reserves versus the continued or increased im-
portation of foreign oil and gas depends in part
on safety considerations. Safety estimates as to
the importation of oil can be derived from tanker
accident statistics of the past. Without proper
regulation the use of super-tankers may cause an
increase in accident rates. Transportation of off-
shore oil by tanker will probably involve a greater
frequency of spills than transportation by pipe-
line. Safety records of offshore production facili-
ties indicate that offshore operations are safer
than onshore operations. However, the increased
exploration and use of deep-water areas and areas
which are prone to seismic activity and extreme
weather changes may cause an increase in the
accident rates. Table IV summarizes the accident
data available for the oil industry.2
TABLE IV
OIL INDUSTRY ACCIDENT DATA
Shipping
Blow-outs
Offshore rigs
Pipelines
Refineries
Accidents/
year
636
11
5
135
*
*
Fatalities/
year
76
*
6
1
3
1
Injuries/
year
37
*
*
1
5915
8155
*Unknown
Contributions of various sources of oil to the oceans
are shown in Table V.3 Uncontrolled non-point sources
such as runoff and natural seeps contribute as much as
accidents within the oil industry. Of industry-related
spills, transportation is responsible for more than half.
Seventy-five percent of oil spills involve vessels. From
1969 through 1973 there were 3,183 shipping accidents.
Three hundred eighty-one fatalities and 178 injuries re-
sulted from these accidents. Collisions and groundings
accounted for about half of the accidents and 44% of
the outflow. Structural failures accounted for 16% of
the accidents and one third of the outflow. The median
size of a spill was 25,000 bbl. Spills usually occurred
within 10 miles offshore and the median duration of a
spill was seventeen days2 (Sec. 4.2.1 p. 80).
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TABLE V
SOURCES OF OIL IN THE OCEANS
SOURCE
ESTIMATED
CONTRIBUTION
(TONS/YR)
Transportation
Tankers, Dry Docking,
Terminal Operations,
Bilges, Accidents
Coastal Refineries, Municipal
and Industrial Waste
Offshore Oil Productions
River and Urban Runoff
Atmospheric Fallout
Natural Seeps
TOTAL
2,350,000
875,000
87,500
2,100,000
660,000
660,000
6,732,500
34.9
13.0
1.3
31.2
9.8
9.8
100.0
Blow-outs and well-casing ruptures are other sources
of oil spills. The National Petroelum Council reported
106 blow-outs in drilling 273,000 wells in the
1960-1970 decade.2 Fires may ensue and uncontrolled
seepage of oil may continue for several months after-
wards (Sec. 4.2.1 p. 91).
Besides causing injury and loss of life to persons in
the vicinity, oil spills (both inland and offshore) also
cause ecological damage. The extent of such damage de-
pends upon the volume, composition and toxicity of oil
spilled, effects of weathering, marine transport, existing
ecosystems, physiography, and clean-up operations em-
ployed. Effects of a spill on estuarine or marine environ-
ments include immediate death to indigenous organisms
such as fish, clams, snails, and crabs, disruption of feed-
ing, reproduction, orientation, and migration patterns of
marine organisms, incorporation of carcinogenic com-
pounds into the food chain, and alteration of habitat so
as to force relocation of species. Also, large numbers of
sea birds may be killed by physical coating of feathers.
Potable water, irrigation, and industrial water supplies
may also be threatened. (Sec. 4.2.1.2 p. 92).
The length of time required for an area to recover
from the effects of an oil spill cannot be specified. Some
believe there are few long term effects; others believe
permanent ecosystem disruption can occur.4 However,
the time for recovery is dependent upon volume and
kind of oil spilled, meteorological conditions, and clean-
up measures. A study of several areas showed that re-
covery was underway 6 months after the oil spill and
nearly complete 3 years after the oil spill.
Since 1955 there have been 100 accidents involving
offshore rigs, each with losses exceeding $500,000.
There were 121 fatalities. Jack up platforms are the type
most susceptible to failure. Major causes of accidents are
moving of rigs and storms (Sec. 4.2.3 p. 102).
In 1975, 135 oil pipeline accidents caused approxi-
mately $3.2 million in property damage, the loss of one
life, one injury, and spillage of 105,871 barrels of oil.
Pipeline accidents are caused by equipment rupturing
lines, internal and external corrosion, structural defects,
human operating errors, vandalism, and adverse natural
events (Sec. 4.2.4 p. 105).
Refinery accidents involve fire and explosions.
Sources (API and National Petroleum Refiners Associa-
tion) differ as to the number of accidents in 1975. One
indicates there were 5,915 injuries and 3 fatalities. The
other says there were 8,155 injuries and 11 fatalities.
Hydrorefining units have the greatest potential for
accidents. Losses for 1965-1969 are summarized in
Table VI. Of these units, hydrocrackers have the worst
accident record. Since 1970 hydrocracker losses have
averaged more than $1,000,000 per year.
Secondary problems associated with refinery acci-
dents are oil spills and air pollution problems. Release of
carbon monoxide, sulfur dioxide, oxides of nitrogen,
hydrocarbons, and particulates may cause illnesses (Sec.
4.2.7 p. 117).
TABLE VI
ACCIDENT LOSS SUMMARY FOR VARIOUS PROCESSES, 1965-1969
Process
Catalytic Cracking
Catalytic Reforming
Hydrocracking
Crude/Vacuum Units
Loss Summary
No. of
Accidents
32
59
19
57
1 965- 1 969
Total Amount
of Losses
$3,308,000
3,134,000
6,402,000
1,366,000
Approximate
Average Loss
$103,000
53,000
337,000
24,000
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Natural Gas and LNG
Summary
Since natural gas and oil often occur together,
extraction and processing technologies are simi-
lar. Therefore, the accidents identified in the oil
section related to these technologies are the same
for natural gas.
More members of the public than employees are
injured or killed by natural gas pipeline accidents.
This is because pipelines transect residential,
industrial and commercial areas.
If natural gas reserves are exhausted in the United
States, alternative domestic resources must be
exploited or natural gas must be imported. Im-
portation of natural gas currently necessitates its
reduction to the liquid state. The transport of
liquified natural gas (LNG) is a subject of contro-
versy and safety aspects in the transportation and
storage of LNG are paramount. Hazards stem
from its cryogenic nature requiring maintenance
of extreme temperatures.
Limited data on LNG transport and storage make
evaluation of risk difficult. Risk analyses are
highly site specific and different models use dif-
ferent assumptions. Consequently, estimates of
risk at specific sites differ by several orders of
magnitude.
Since oil and natural gas are frequently found to-
gether, extraction and processing accidents involving one
also involve the other. Therefore, the types of accidents
identified in the oil section related to these technology
steps are the same for natural gas. Blowouts of well-
heads during the drilling of exploratory and production
wells, release of sulfur compounds during processing,
and failures of pipelines due to corrosion or outside
forces comprise the bulk of the accidents occurring from
this energy source. Table VII summarizes the accident
data available for the natural gas energy system:5
Pipeline distribution accounted for the greatest num-
ber of injuries per 1012 BTUs.5 Accident rates for
offshore extraction, gathering, and processing are an
order of magnitude lower. Onshore extraction accounted
for the greatest number of fatalities per 1012 BTUs.5
Drilling operations were responsible for the highest fre-
quency of disabling injuries at 48.93 accidents per mil-
lion man hours worked (Sec. 5.2 p. 127).
Processing accidents are those occurring during the
separation of oil and gas and the removal of impurities.
One of the greatest problems is removal of the highly
toxic gas hydrogen sulfide. In 1975, gas processing was
responsible for 921 injuries and 3 fatalities (Sec. 5.2.3 p.
137).
Almost all pipeline accidents can be attributed to cor-
rosion, damage by outside forces, construction defects,
or material failure. The Eighth Annual Report of Pipe-
line Safety summarized gas pipeline accidents during
1975 by distribution and transmission and gathering
categories. This is shown in Table VIII.6 With a total of
1,373 failures this amounts to 0.01 fatality per failure
and 0.11 injury per failure. Pipeline transportation poses
a significant hazard to the general public because pipe-
lines transect residential and commercial areas (Sec.
5.2.4 p. 137).
Technology
Pipeline distribution
Extraction
offshore
onshore
Transmission and gathering
Processing
natural gas liquid
hydrogen sulfide
TABLE VII
NATURAL GAS ACCIDENT DATA
Fatalities/1012 Btu
0.000040
0.000007
0.000080
0.000006
0.000040
0.000002
Injuries/10lz Btu
0.0138
0.0030
0.0040
0.0010
0.0040
0.0020
Fatalities/year
16
6
Injuries/year
220
17
921
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TABLE VIM
PIPELINE ACCIDENT DATA-1975
Mode
Distribution
Transmission and Gathering
Total
Non-Employee.
Injuries
191
9
200
Liquified natural gas, LNG, is composed primarily of
methane (95%) with small impurities of light hydro-
carbons. The technology for reducing gaseous methane
to the liquid phase has been known for several decades.
It has been used since the 1940's for storage purposes.
There are now 23 liquefaction plants, 49 operational
peak shaving plants, and 49 satellite storage facilities in
the United States.
Recently there has been increased interest in trans-
porting natural gas in this form across the seas. Liquefac-
tion is desirable because liquified methane occupies only
1/600 of its gaseous volume and large quantities can
therefore be transported. Currently, there is only one
functioning LNG terminal in the United States. It is lo-
cated in Everett, Massachusetts and operated by DIS-
TRIGAS. Several terminals are in the planning and early
approval stages. Alaska, California, the Gulf of Mexico
and Mid Atlantic states are the most likely sites (Sec. 6.1
p. 150).
There exist no accident data on transport of LNG via
tanker and only four accidents are known to have oc-
curred at LNG storage facilities. Consequently, there
exists an inadequate data base from which to predict
frequency and severity of accidents. Caution generally
has been exercised by those individuals responsible for
approving construction on LNG terminals. This is due in
part to questions concerning the need for LNG and the
potential for a catastrophic accident.
The most severe accident occurred in Cleveland, Ohio
in 1944. A large storage tank containing 38,000 barrels
of LNG collapsed because of brittle fracture. A spread-
ing pool fire resulted. The burning pool flowed into the
surrounding community. The fire and resulting explo-
sions killed 130 people, injured 300, and caused prop-
erty damage of $10,000,000. The likelihood of an acci-
dent caused by brittle fracture recurring it, very low be-
Non-Employee
Fatalities
Employee
Injuries
29
8
37
Employee
Fatalities
0
5
cause of the development of materials able to withstand
the extreme cold of cryogenic temperatures.
Three other accidents involved LNG storage facilities.
In February 1973 an empty LNG storage tank on Staten
Island exploded and burned. Forty workers died. The
explosion was attributed to ignition of trapped vapors
by a welder's torch. In Oregon, a tank exploded during
construction before LNG was introduced. Four workers
died. Investigators attributed the accident to careless
work practices. In 1972, gas leaked through an air line to
the control room of an LNG plant in Montreal, Canada.
A large fire resulted.
Besides failure of a storage tank, those accidents
which are considered to have the greatest potential for
harm are collisions of tarjkers at sea where the contents
of one or two LNG tanks are released. (The average tank
size is 37,500 cu. m.).? Minor accidents include release
of refrigerants, solids blocking the transfer pipeline, mal-
functions onboard tankers, leaks in the transfer system,
and maintenance accidents.
Since a sufficient body of historical data does not
exist, risk analyses have been performed to determine
the probabilities and consequences of accidents involving
LNG terminals. Three studies are presented which con-
sidered three sites—Los Angeles, Oxnard, and Point Con-
ception, California. The models were developed by the
Federal Power Commission (FPC), Science Applications,
Inc. (SAI), and the El Paso Alaska Company (EAC). The
differences in risk estimates are the results of different
assumptions and modelling procedures. These risk esti-
mates apply only to the sites for which calculations were
made. The risk of fatalities at other sites may be substan-
tially different (Sec. 6.3 p. 165). Results appear in Table
IX. Estimates range from one fatality in 10,000 years to
one fatality in 1,000,000,000 years.
TABLE IX
LNG RISK ANALYSIS-MILLION YEARS PER FATALITY
Los Angeles
Oxnard
Pt. Conception
Model
Federal Power Commission
Science Applications, Inc.
El Paso Alaska Company
Marine
10
Terminal
0.01
10.00
Marine
1
100
Terminal
10
Marine
0.1
1000.0
100.0
Terminal
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Hydroelectric and Other Electric Power
Summary
Hydroelectric power is the safest method of
power generation. However, this resource is
capable of supplying only 25% of the nation's
requirements. Although only one failure has
occurred of the more than one thousand operat-
ing hydroelectric dams in the United States, 11
lives were lost and more than $1 billion of prop-
erty damage occurred. Failures of other dams
could have similar consequences. Consequently,
there is a need to examine the potential for failure
of other hydroelectric dams.
Utilities rank tenth in frequency of injuries
among all industries. In terms of frequency
of accidents the following ranking occurs:
oil> coal> hydroelectrio nuclear.
In 1974 hydroelectric facilities generated about 16%
of the electricity used in the United States. The North
Pacific area accounted for more than one-third of the
United States capacity. If the source were developed to
its full potential, it could supply about 25% of the na-
tion's present electrical needs.
Although more than a thousand dams supply hydro-
electric power in the country, only one failure has oc-
curred. This was the Teton Dam in Idaho which failed in
June 1976. The breaching caused $1 billion in damage,
caused 11 deaths and killed 13,000 cattle. The Depart-
ment of Interior determined that the cause of the failure
was improper design. A study of thirteen problem dams
has been initiated (Sec. 7.2 p. 178).
Other possible causes of dam failure are undermining
caused by erosion, forces exceeding design for water
pressure, ice pressure, earth pressure, and earthquake
forces. A severe loss of water without dam failure can
occur through seepage.
The estimated effects of damage in terms of fatalities
and monetary losses upon the failure of selected dams
appears in Table X.8 Fatalities could reach hundreds of
thousands and monetary losses approach hundreds of
millions of dollars.
Within the hydroelectric plant several types of acci-
dents can occur. The most serious would be plant inun-
dation caused by conduit failure, extreme river flow or
conventional openings within equipment, resulting in
failure of turbine and damage to the electrical circuits
and generator.
Personnel accidents involving construction, mainten-
ance, and normal operations are the most frequent A
survey of four types of power plants (coal, oil, hydro-
electric, and nuclear) indicates that for hydroelectric
plants, the occupational injuries occur at approximately
one-half the frequency and one-tenth the severity asso-
ciated with all electric generating plants. The survey,
covering 1969-1972 reported 4.1 disabling work injuries
per 1 million employee-hours exposure.
Approximately 25% of the total energy consumed to-
day is used for electric power generation. By the year
2000 it is expected that this figure may increase to 40%.9
Electricity production from all energy sources in 1974
totaled 1.86 x 1012 KWhe and the projection for 1990
is 4.7 x 1012 KWhe. In 1974, coal provided 44.5%, oil
provided 16.0%, gas provided 17.2%, hydroelectric
power provided 16.1%, and nuclear power provided
6.0% of the electric power generated in the United
States.
Data on accidents associated with electrical power
generation are sparse. Federal Power Commission (FPC)
regulations require accidents be reported only in the case
of a power outage. Thus, accidents in which power is
maintained but which cause death or injury would not
be reported.
A serious accident which can occur at a boiler-fired
plant is explosion of the boiler. Operation at elevated
temperatures and pressures increase the chances of this
happening. Fires and explosions can also occur in the
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TABLE X
ESTIMATED EFFECTS OF TOTAL FAILURE OF DAM FILLED TO CAPACITY
NAME
Van Norman Dam
San Andreas Dam
Stone Canyon Dam
Encino Dam
San Pablo Dam
Folsom Dam
Chatsworth Dam
Mulholland Dam
Lake Chabot Dam
Shasta Dam
*No allowance for evacuation.
FATALITIES*
DAY
72,000
21,000
125,000
11,000
24,000
260,000
14,000
180,000
36,000
34,000
NIGHT
123,000
33,000
207,000
18,000
36,000
260,000
22,000
180,000
55,000
34,000
DAMAGE IN U.S. DOLLARS
300,000,000
110,000,000
530,000,000
50,000,000
77,000,000
670,000,000
60,000,000
720,000,000
150,000,000
140,000,000
handling of fuel. Other additional but infrequent acci-
dents that can occur in a boiler fired plant are implosion
of the condenser and tube and steam line rupture.
The most severe accidents which may occur at a gas
turbine plant are explosion, asphyxiation, and ruptured
lines. Explosions can occur in the turbine, compressor,
combustor, and recuperator. Asphyxiation may be
caused by accidental release of toxic substances such as
hydrogen sulfide, carbon monoxide, and coal tar vola-
tiles.
Other accidents which may occur in the generation of
electricity include power failure, flooding, electrical
fires, and occupational injuries. Power failures cause
widespread but minor damage. Customers experience
loss of electricity over a wide area. Power failures may
be caused by factors internal or external to the power
plant. Causes include generator malfunction or line fail-
ure caused by lightning strikes, falling trees, ice accumu-
lation, and vehicles striking power poles. Occupational
injuries include back strain, electrical burns, steam
burns, and shock.
National Safety Council data for 1972 show that, for
sampled electric utilities, the frequency rate for fatal and
permanent total disability was 0.12 injuries per million
person hours exposure. The utilities ranked tenth in the
frequency of injuries among all industries. In terms of
frequency of injuries (number of disabling work injuries
per million employee-hours exposure) the following
ranking occurs (1972 data); oil (13.69)>coal
(10.8)>hydroelectric (4.1)>nuclear (3.0). In terms of
severity of accidents (total days charged for work in-
juries per million employee hours exposure) the follow-
ing ranking occurs (1972 data): coal (1950)>oil
(461)>hydroelectric (149)>nuclear (43).
In addition to electric power generation, other end
uses are transportation and industrial, residential, and
commercial use. Transportation accounts for 25% of the
energy consumption of the United States. The industrial
sector consumes 28% and the residential/commercial use
is 23%. Transportation accidents occur frequently and can
be considered major. The most common is vehicle colli-
sion. Other accidents involve aircraft, motorized farm
equipment, and ships. In the industrial sector, fires, ex-
plosions, and floods comprise a major proportion of the
accidents. Commercial/residential sector accidents are
frequent but minor. Most home accidents do not involve
the use of energy. However, accidents involving appli-
ances and heating and other equipment can cause injury,
damage to equipment, or fire.
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Developing Energy Systems
Summary
It is difficult to evaluate developing energy tech-
nologies in terms of safety. No operating data
exists and extrapolations must be made from
demonstration plants or from similar technolo-
gies.
The United States has vast deposits of oil shale,
but current oil prices have not necessitated their
development. The frequency and severity of ac-
cidents associated with oil shale development
probably will be dependent upon the ratio of
open pit to underground mining.
There has been little experience with solar energy
systems in the United States. Although most ac-
cidents associated with solar energy use are ex-
pected to be minor, occasionally major accidents
may occur.
Geothermal
The geothermal resources are based on the tempera-
ture distribution within the earth, ranging from very
high temperatures at the core to mild temperatures at
the surface. There is limited operating experience with
this energy source, the longest United States experience
being 15 years. A major accident which may occur in
association with the development of geothermal energy
is a blowout causing the release of hot fluids, steam, and
other gases found in geothermal fluids. Blowouts may
occur during drilling operations or during steady state
operations. In the latter situation, the blowout would be
caused by structural failure of the cements and casing
materials in the well. A blowout can cause the loss of an
entire rig with the drill string operator suffering possible
injury or death. In the extreme, the ground may sud-
denly open and the entire rig collapse into the chasm.
One type of blowout which occurred at the Geysers was
caused by the instability of the formation (an old land-
slide) through which the well passes. The unconsolidated
nature of the landslide allowed the steam to escape into
the ground with the potential of eruption when attempts
were made to cap the well.
Earthquakes could have a severe impact on a geo-
thermal facility. They may cause pipeline ruptures and
well splitting. The latter could cause contamination of
potable water supplies. Pressure buildup due to silica
precipitation may also cause pipeline leaks or ruptures
(Sec. 8.2 p. 194).
Subsidence, a very slow process, is also a possibility.
This has occurred at Wairakei, New Zealand where sub-
sidence has totalled 4 meters since 1956. Subsidence can
cause damage to buildings and equipment and flooding
may occur in low lying coastal areas. Seismicity, a more
sudden occurrence, may be induced by injection of
spent geofluids. The likelihood and severity of such an
event has not been evaluated.
Oil Shale
Oil shales are shales which have a high organic con-
tent. The organics are recoverable by pyrolysis at tem-
peratures around 350°C. The United States has vast de-
posits of oil shale. The government has leased four tracts
for development, but at current petroleum prices it is
not yet clear that these leases will lead to production
before 1985. An assessment of the potential for accident
in the oil shale industry must be based on engineering
judgment because there is no commercial scale develop-
ment of oil shale (Sec. 9.0 p. 196).
Roof collapse, blasting accidents, dust explosions,
and subsidence during extraction, explosions during
processing especially during hydrogenation, pipeline rup-
tures during transportation, and loss of ground water
control due to failure of retaining dams are possible
major accidents (Sec. 9.2 p. 202). The accident record of
this industry may be dependent upon whether surface or
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underground mining techniques are used. Both are possi-
ble but one cannot predict which will predominate. If
open-pit mining should prevail, one study suggests that
oil shale accident rates will be more similar to copper
mining than to coal mining. Metal mining fatalities in the
western states in 1972 totalled 14 and injuries totalled
1331. This amounted to 0.25 deaths/million employee-
hours and 24 injuries/million employee-hours. The
latter figure is intermediate between the injury rates
given for surface mining of coal (10 injuries/million em-
ployee-hours) and for underground mining of coal (35
injuries/million employee-hours).
Solar Energy
Solar energy has not yet been used to an appreciable
extent because the technologies have not been suffi-
ciently developed and potential users have little experi-
ence in utilizing solar-type systems. Four types of solar
energy have been considered. They are direct conversion,
wind, tidal and wave, and biomass conversion.
The three methods of direct conversion of solar en-
ergy are photo-voltaic, solar-thermal, and ocean thermal
energy conversion (OTEC). The accidents associated
with photovoltaic conversion probably will be minor and
infrequent. These accidents will involve solar cell break-
age, wire failure, DC/AC converter failure, and electrical
fires. Monetary losses associated with solar-thermal acci-
dents may be major if the reflector was damaged or the
boiler ruptured. OTEC accidents may be major if trans-
mission pipelines suffer corrosion or if fires or explo-
sions occur during the ocean based manufacture, storage
or transport of the oxygen and hydrogen produced. Other
possible injuries may result from glare or concentrated
radiation. Occupational injuries for solar power are esti-
mated at 0.5-1.6 man-days lost/MWe/year (Sec. 10.2
p. 218).
Accidents associated with wind energy systems in-
clude production of air turbulence, broken rotor blades,
ice shedding from blades, and possible collapse of the
unit as a result of design error, storm, or earthquake.
Accidents associated with tidal energy systems may in-
clude flooding, structural collapse, control gate failure,
and marine ship collisions. Biomass conversion systems
may experience accidents such as explosions and fire
linked to methane or hydrogen and oxygen production
(Sec. 10.2 p. 220).
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Adverse Natural and Other Incidents
Summary
Natural disasters cause many hundreds of deaths
and billions of dollars of damage annually. Much
of the nation's oil and gas resources are located
in areas prone to hurricanes and seismic activity.
Little can be done to stop these events and the
best protection lies in building of structures to
withstand these natural shocks, choice of opti-
mum location and formulation of emergency
procedures so as to minimize detrimental results.
Unintentional human-caused adverse events such
as airplane or missile crashes do not present a
significant threat to energy installations. How-
ever, improper siting could greatly increase the
risk. Acts of sabotage could disrupt or destroy
energy production or transportation in a given
geographical sector.
Natural incidents include hurricanes, tornadoes,
floods, tsunamis, snow and ice storms, earthquakes, land
subsidence, avalanches and landslides, volcanic erup-
tions, and meteorite impact. Anthropogenic incidents in-
clude airplane and missile crashes, sabotage, terrorism,
and war activities.
The effect of a natural disaster on an industrial in-
stallation can be as severe as a nuclear blast detonating a
few miles from the plant. Up to 26 natural disaster areas
are declared in the United States per year. They are
responsible for about 500 to 600 fatalities annually and
economic losses average $10-15 billion (Sec. 12.1 p.
240).
The types of damage produced by natural disasters
include flood damage to storage facilities, processing
facilities, and transmission lines, physical stress damage
tojjrocessing facilities, rupturing of pipelines and explo-
sions and fires resulting from escaped gases and highly
flammable liquids.
The destruction potential of man-caused adverse
events is great. No industrial installation is immune to
sabotage but damage is usually minor and the act is con-
sidered as an irritant. However, a well-planned act of
sabotage or a nuclear weapon could completely demolish
all structures within an area. Unintentional events, i.e.,
aircraft and missile crashes do not usually present a sig-
nificant threat to energy installations (Sec. 12.2 p. 252).
For Further Information
1. Bliss, C. et al., Accidents and Unscheduled Events
Associated with Non-Nuclear Energy Resources and
Technology, EPA-600/7-77-016, February, 1977, pp.
273.
2. National Petroleum Council. Environmental Con-
servation—The Oil and Gas Industries (2 Volumes).
Washington, D.C., 1971 and 1972.
3. National Academy of Sciences, Petroleum in the Mar-
ine Environment, Washington, D.C., 1975, pp.
104-107.
4. Blumer M. Oil Contamination and the Living Re-
sources of the Sea. In: FAO Technical Conference on
Marine Pollution and Its Effects on Living Resources
and Fishing. Rome, Italy, December 1970.
5. University of Oklahoma, 1975. Energy Alternatives, a
Comparative Analysis. Science and Public Policy Pro-
gram. Norman, Oklahoma. 1975. pp. 1.1-1.121.
6. Department of Transportation, Eighth Annual Report
on the Administration of the Natural Gas Pipeline
Safety Act of 1968, 1975, pp. 1-30.
7. Philipson, Lloyd L., "The Systems Approach to the
Safety of LNG Import Terminals." Prepared for the
State of California Energy Resources Conservation
and Development Commission, Draft Report, pp.
VI-1 to VII-3.
8. Ayyasenamy, P., B. Hauss, T. Hsiih, A. Mascati, T. E.
Hicks, and D. Okrent. Estimates of the Risks Asso-
ciated with Dam Failure. Prepared for the United
States Atomic Energy Commission. University of
California at Los Angeles, 1974, p. 375.
9. Penner, S. S. and L. Icerman. Energy: Non-Nuclear
Energy Technologies, Vol. 2. Addison-Wesley, Read-
ing, Massachusetts, 1975.
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