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I
must begin with an apology for the fact that this paper is
written from the standpoint of an American citizen.
All of my research has been based on U.S. as a "laboratory",
using U.S. statistics and U.S> experience and
practices. Hopefully, much of it is applicable to
other countries. The Material to be presented is
covered in my book "The Nuclear Energy Option" (Plenum
Publishing Co., New York; 1990), which also includes its
technical justification.
Avoiding the environmental problems of fossil
fuels
One important advantage of nuclear power is that is avoids
the wide variety of environmental problems arising
from burning fossil fuels - coal, oil, and gas.
These environmental problems probably exceed those of any
other human activity. The ones that have received the
most publicity have been "global warming", which is changing
the Earth's climate; acid rain, which is destroying forests
and killing fish; air pollution, which is killing tens of
thousands of Americans every year, while degrading our
quality of life in many ways; the destructive effects of
massive mining for coal; and oil spills which do great harm
to ecological systems.
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"Some
of the most important problems caused by acid rain
are political."
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Global
warming: Burning fossil fuels produces vast
quantities of carbon dioxide, for example 3.7 tons for each
ton of coal burned, and carbon dioxide in the atmosphere
traps heat, increasing the earth's temperature.
Estimates of the rate of the temperature rise and of the
consequences vary, but eventually the effects are bound to
be important. Agriculture is very sensitive to climate
and hence will be heavily affected, requiring shifts in
crops that cannot be grown in different areas.
Livestock will be affected through problems in breeding,
diseases, and pest control. Forests will come under
heavy stress as growing areas for each tree species shifts
and insect populations, disease patterns, competition from
other plants, and factors affecting fires change.
Eventually, the melting glaciers will cause sea levels to
rise - this floods valuable land, escalates the frequency
and severity of disasters from hurricanes, allows inland
penetration of salt water which heavily impacts aquatic life
(e.g. oyster harvests), and leads to loss of urban water
supplies and contamination of groundwater. Effects of
changing storm tracks, rainfall, and wind patterns are bound
to be important.
The global warming issue has been the subject of a series of
high level international conferences, culminating in a still
unratified agreement to reduce carbon dioxide emissions, the
implementation of which is estimated to cost the U.S.
economy hundreds of billions of dollars per year.
Acid rain: Burning fossil fuels
releases large quantities of sulphur dioxide and nitrogen
oxide gasses which combine with moisture in the air to
produce acids that fall with rain. The effects are
complicated and conclusions about them are controversial,
but there is strong evidence that, in some cases, acid rain
is making lakes unlivable for fish and is badly damaging
forests.
Some of the most important problems caused by acid rain are
political. The emissions from coal burning power plants in
Midwestern U.S. are the cause of acid rain in Eastern Canada
and this has been a top priority political issue in Canada,
making it an important sources of difficulty in U.S.
Canadian relations. The situation is similar in Europe
where coal burning emissions from Britain are damaging lakes
and forests in Scandinavia and Germany.
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"30,000
deaths per year in U.S. result from air pollution
due to emissions from fossil fuel burning power
plants."
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Air
Pollution: While global warming causes only
economic disruption, and acid rain kills only fish and
trees, air pollution kills people and causes human suffering
through illness. Vast amounts of research have gone
into understanding the processes involved and tying down the
responsible components, but successes have been limited.
There are well recognised health effects from many of
the components, sulphur dioxide, nitrogen oxides, carbon
monoxide, fine particulates, hydrocabons, ozone,
volatile
organic compounds, and toxic metals,
but probably the health effects result from combinations of
several of these. The problem is complicated by the
fact that effect build up slowly over many years or decades,
causing illness and weakening constitutions to the point
where death eventually results but is not obviously tied to
air pollution. The epidemiological evidence, however,
seems fairly clear in indicating that something like 30,000
deaths per year in U.S. result from air pollution due to
emissions from fossil fuel burning power plants.
Shifting from fossil fuel to nuclear power would avert these
deaths, and if electricity becomes much more widely used for
transportation (e.g. with electric cars), the life saving
would be much larger. Human discomfort ill health is
an important part of the price we pay for burning fossil
fuels. Economic losses from worker absence and/or
reduced efficiency due to illness are also
substantial.
Air pollution discolours and otherwise damages buildings,
soils clothing, and makes for a generally dirty environment,
which adversely impacts on our quality of life.
Coal mining: Sixty percent of U.S.
coal is obtained by strip mining, which involves removing up
to 200 feet of covering soil. There are laws and good
faith efforts to reclaim the land, but these have had only
limited success, and the land is often left badly
scarred. The remaining 40% of coal comes from
underground mines, and this percentage is increasing.
Acid drainage from these mines gets into streams, killing
fish and leaving the water unfit for drinking, swimming, or
many industrial applications. About one-fourth of the
8 million acres of U.S> land about coal mines has
subsided causing buildings on the surface to crack or even
be destroyed, and often changing drainage patterns so as to
make land unfit for farming. There are hundreds of
long lasting fires in U.S. mines which release air polluting
smoke and vegetation-destroying heat, often for many
years. Waste banks from coal washing outside mines are
unsightly and frequently catch fire, leading to another
sources of air pollution.
Oil Spills: The highly publicised
40,000 ton oil spill off the coast of Alaska in 1989, even
after 10 years of clean-up costing several billion dollars,
has still left substantial long term damage to the ecology
of the region. But there have been much larger oil
spills, including one of 305,000 tons off the coast of
Tabago in 1979 and one of 237,000 tons, which ruined many
miles of French beaches in 1978. U.S. tankers spill
several hundred thousand tons of oil each year on average.
At any given time, 100 million tons of oils being
transported by ships, so accidental spills are
inevitable. Land based accidents can also be
important. A Mexican well that could not be capped
spilled 700,000 tons of oil into the Gulf of Mexico in 1979,
doing extensive damage to the aquatic life.
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"There
are much easier, faster, and cheaper ways for a
nation to develop nuclear weapons than through a
nuclear power programme."
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Fuel
resources
Another nuclear advantage is in the nature of the fuel
consumed. Oil and gas are the principal fuels used for
space heating and for transportation, and are
difficult to replace in those applications. The
world's supply of these is limited, probably enough
for less than 100 years of projected consumption, and costs
are bound to rise sharply long before supplies are
exhausted. Coal can be used to produce further
supplies of oil and gas, but its supply is also
limited. Coal, oil and gas are the principal
feedstocks for producing plastics and organic chemicals,
without which our technological society would be severely
crippled. There is thus every reason to preserve our
supplies of fossil fuels. Uranium for nuclear fuel,
on the other hand, has little value for other purposes, and
with breeder reactors, there is enough to satisfy World
energy needs for billions of years, without increasing the
cost of electricity by as much as one percent.
Waste disposal issues
We have been bombarded with propaganda about the potential
dangers of long lived radioactive waste from nuclear
reactors. But these wastes have the extremely
important advantage of being very small in volume and can be
easily contained so they can be buried deep
underground. The results of an analysis, shown in
Table 1, indicate that the wastes from coal burning,
including those that end up in the ground, are far more
dangerous. These include chemical carcinogens like
beryllium, cadmium, arsenic, nickel, and chromium which,
unlike the nuclear wastes, last forever. They also
include uranium, which occurs as an impurity in coal, ends
up in the top surfaces of the ground, and serves as a source
for random emissions; nuclear power, in contrast, consumes
uranium, thus averting future deaths from exposure to radon
gas as indicated by the negative sign in Table 1.
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Table
- 1: Eventual number of deaths caused by the wastes
from generating 1000 MWe-y of electricity
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Nuclear
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High
level waste
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0.018
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Radon
emissions
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-420*
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Routine
emissions (Kr, Xe, C-14, H-3)
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0.3
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Low
level waste
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0.0004
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Coal
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Air
pollution
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75
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Radon
emissions
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30
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Chemical
carcinogens
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70
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Solar
(photovoltaics)
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Coal
for materials
(steel, glass, aluminium)
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3
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Cadmium
sulphide (if used)
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80
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*The
negative number indicates deaths averted, rather
than caused.
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Nuclear
bombs
Much has been made of the connection between nuclear power
and nuclear bombs, although the relationship is really very
weak. There are much easier, faster, and cheaper ways
for a nations to develop nuclear weapons than through a
nuclear power programme. All nuclear weapons states
have developed their bombs independently from their
electricity generation facilities, and any nation with a
serious desire to obtain nuclear weapons could and would do
the same. The problem here is not so much to avoid the
development of nuclear bombs that is essentially a lost
cause as to avoid their use. One of the most likely
scenarios for their use is in fighting over oil as world
supplies dwindle to precarious levels during the
twenty-first century. Oil resources are limited and
located largely in the politically unstable Middle East, so
that competition for it can become intense. The 1991
Persian Gulf War could easily be a forerunner of much more
serious confrontations. However, electicity can
replace oil for space heating, and produce hydrogen as a
substitute for oil in transportation applications.
Nuclear Power thus has the advantage of mitigating the need
for oil, thereby avoiding one of the prime potential reasons
for using nuclear bombs.
Accident risks
The public has been bombarded with fears of reactor
accidents, nearly always focussing on the effects of the
worst accident evaluated in some study, and never treating
the probability of such an accident. In fact, it is
often said that probability doesn't matter; the only
important thing is the worst possible accident. To
face the accident risk squarely, one must recognise that it
is absolutely essential for probability to be considered
because there is no such thing as the worst possible
accident - any hypothetical accident can be made worse by
extenuating circumstances, albeit with reduced
probability.
For example, one of the innumerable gasoline tank trucks
that roam our streets can have a collision spilling the
fuel, leading to a fire that could destroy a whole city,
killing millions of people. It might require a lot of
improbable circumstances combining together, like water
lines being frozen to prevent effective fire fighting, a
traffic jam aggravated by road construction or other
accidents limiting access to fire fighters, substandard gas
pipes which the heat of the fire cause to leak, a high wind
frequently shifting to spread the fire in all directions, a
strong atmospheric temperature inversion after the whole
city becomes engulfed in flame to keep the smoke close to
the ground, bridges and tunnels closed for various reasons
to eliminate escape routes, errors in advising the public,
and so forth. Each of these situations, is improbable,
so a combination of many of them occurring in sequence is
highly improbable, but not impossible. If any anyone
thinks that is the worst possible accident, consider the
possibility of the fire being spread by glowing embers to
other cities which were left without protection because
their fire fighters were off assisting the first city,
etc.
As an example for nuclear's chief competitor, coal burning,
consider the possibility of the abundant mutagenic chemicals
it produces leading to development of a virus that could
wipe out mankind; a virus as deadly as HIV that could be as
easily spread as the influenza virus could come close to
that! There is no such thing as the worst possible
accident, and probability must be considered.
This is another important advantage for nuclear power - the
probabilities have been determined and they are very small
indeed. The best way to display this advantage is to
compare the risks of nuclear power with other risks.
This is shown in Table 2 in terms of the loss of life
expectancy, LLE they cause.
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Table
- 2: Loss of life expectancy (LLE) due to various
risks in U.S.
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Activity
or risk
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LLE(days)
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Living
in poverty
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3500
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Smoking
cigarettes (1 pack/day)
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2300
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*Heart
disease
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2100
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Being
unmarried
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2000
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Working
as a coal miner
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1100
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*Cancer
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980
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Being
30 pounds overweight
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900
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*Motor
vehicle accidents
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150
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*Suicide
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95
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*Homicide
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90
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*Air
pollution
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80
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Small
car vs midsize car
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60
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*Speed
limit 65 vs 55 miles per hour
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40
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*Falls
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39
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*Poison
+ asphyxiation + suffocation
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37
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*Road
in homes
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35
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*Fire
and burns
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27
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*Dam
failures
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1
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Living
very near a nuclear power plant
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0.4
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*All
U.S. Electricity nuclear
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0.04
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*All
U.S. Electricity nuclear - accidents only
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0.012
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*Asterisks
indicate average over total U.S. Population; others
refer to those exposed.
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Note
that a substantial fraction of air pollution is due to
fossil fuel power plants and that dam failures are largely
tied to electricity generation. Oil and natural gas
contribute to fires, and the latter is an important
contributor to asphyxiation. A very important
contributor to dangers from energy usage is conserving
energy which causes us to use smaller cars, with the
attendant danger from Table - 2, and to tighten our homes
which increases indoor air pollution which is now regarded
to be more important that outdoor air pollution. One
example of this is increased radon in homes which gives us
hundreds of time as much radiation as nuclear power.
It is clear from Table - 2 that nuclear accidents are not an
important problem, and their very low probability is a great
advantage of nuclear power.
This advantage can perhaps be expressed more clearly by
saying the risk to an average American of a very large
nuclear power program in U.S. is equivalent to the risk of a
regular smoker smoking one extra cigarette every 15 year, or
to the risk of an overweight person increasing his weight by
0.012 ounces, or of raising the U.S. highway speed limit
from 55 to 55.006 miles per hour.
Summary
Nuclear power has advantages in many areas, including some
that have been traditionally viewed as problem areas it
averts the pollution and environmental degradation of fossil
fuels, it guarantees the world an everlasting supply of fuel
without affecting resources sorely needed for other
applications, it solves difficult waste management problems,
it contributes to avoidance of nuclear warfare, and it
diminishes risks from accidents.
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Dr.
Bernard L. Cohen is Professor-Emeritus of
Physics and Astronomy and of Environmental and
Occupational Health at University of Pittsburgh. He
has authored 6 books, over 300 papers in scientific
journals, and about 75 articles in non-technical
journals. He has presented invited lectures
in 47 U.S. States, 6 Canadian provinces, 7 Japanese
prefectures, 6 Australian states and territories,
and 24 other countries in Europe, Asia and South
America. His awards include the American
Physical Society Bonner Prize, the Health Physics
Society Distinguished Scientific Achievement
Award. He has been elected Chairman of the
Division of Nuclear Physics of the American
Physical Society, and Chairman of the Division of
Environmental Sciences of the American Nuclear
Society.
He enjoys outdoor sports,
plays golf, and is also devoted to his family and
eight grand children.
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