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Energetic Costs of Nuclear Power

 

[Chapter 1 from Nuclear Power is Not the Answer by Helen Caldicott]

The Nuclear Energy Institute (NEI), the propaganda wing and trade
group for the American nuclear industry, spends millions of dollars
annually to engineer public opinion. Advertisements such as the one
on page 5 [not shown here] have been published extensively by the NEI in Scientific
American, the New Yorker, the Washington Post, and Capitol Hill publications
such as Roll Call, Congress Daily AM, and The Hill.1 The primary
goal of such ads is to establish the premise that nuclear energy
is “cleaner and greener” than traditional sources of electricity. Sentences
such as “our 103 nuclear power plants don’t burn anything, so
they don’t produce greenhouse gases” imply that nuclear energy is a
more environmentally conscious choice than, say, electricity produced
from coal or oil—the traditional sources of fuel across the
globe—one that will produce far less carbon dioxide and thus spare
us the global warming problems now associated with these other energy
sources.

But a clear-eyed look at the true costs of nuclear energy production
tells a very different story. The fact is, it takes energy to make
energy—even nuclear energy. And the true “energetic costs” of
making nuclear energy—the amounts of traditionally generated fuel
it takes to create “new” nuclear energy—have not been tallied up
until very recently. Certainly, they are absent from the NEI ads.

What exactly is nuclear power? It is a very expensive, sophisticated,
and dangerous way to boil water. Uranium fuel rods are
placed in water in a reactor core, they reach critical mass, and they
produce vast quantities of heat, which boils the water. Steam is
directed through pipes to turn a turbine, which generates electricity.
The scientists who were involved in the Manhattan Project
creating nuclear weapons developed a way to harness nuclear
energy to generate electricity. Because their guilt was so great,
they were determined to use their ghastly new invention to help
the human race. Nuclear fission harnessed “atoms for peace,”
and the nuclear PR industry proclaimed that nuclear power
would provide an endless supply of electricity—referred to as
“sunshine units”—that would be good for the environment and
“too cheap to meter.”

They were wrong. Although a nuclear power plant itself releases
no carbon dioxide, the production of nuclear electricity depends
upon a vast, complex, and hidden industrial infrastructure
that is never featured by the nuclear industry in its propaganda, but
that actually releases a large amount of carbon dioxide as well as
other global warming gases. One is led to believe that the nuclear
reactor stands alone, an autonomous creator of energy. In fact, the
vast infrastructure necessary to create nuclear energy, called the nuclear
fuel cycle, is a prodigious user of fossil fuel and coal.

The production of carbon dioxide (CO2) is one measurement
that indicates the amount of energy used in the production of the
nuclear fuel cycle. Most of the energy used to create nuclear
energy—to mine uranium ore for fuel, to crush and mill the ore, to
enrich the uranium, to create the concrete and steel for the reactor,
and to store the thermally and radioactively hot nuclear waste—
comes from the consumption of fossil fuels, that is, coal or oil.
When these materials are burned to produce energy, they form
CO2 (reflecting coal and oil’s origins in ancient trees and other
organic carboniferous material laid down under the earth’s crust
millions of years ago). For each ton of carbon burned, 3.7 tons of
CO2 gas are added to the atmosphere, and this is the source of today’s
global warming.

CO2 and other gases hover in the lower atmosphere or troposphere,
covering the earth like a blanket, and this gaseous layer behaves
like glass in a greenhouse. Visible white light from the sun
enters the atmosphere, heating up the surface of the earth, but the
infrared heat radiation created cannot pass back through the terrestrial
layer of trapped gases. Carbon dioxide accounts for 50% of
the global warming phenomenon,3 and other rare gases comprise
the rest.

The total energy input of the nuclear fuel cycle—the energetic
costs of nuclear power—must be openly and honestly assessed
if nuclear power is to be compared fairly with other energy
sources. Very few studies are yet available that analyze the total life
cycle of nuclear power and its final energy input versus output.
One of the best is a study by Jan Willem Storm van Leeuwen and
Philip Smith titled “Nuclear Power—the Energy Balance.” Much
of the material for the next section has been derived from this excellent
report.

To quote the final conclusion of their lengthy analysis, “The
use of nuclear power causes, at the end of the road and under the
most favourable conditions, approximately one-third as much carbon
dioxide (CO2) emission as gas-fired electricity production. The
rich uranium ores required to achieve this reduction are, however,
so limited that if the entire present world electricity demand were
to be provided by nuclear power, these ores would be exhausted
within nine years. Use of the remaining poorer ores in nuclear reactors
would produce more CO2 emission than burning fossil fuels
directly."  In this instance, nuclear reactors are best understood as
complicated, expensive, and inefficient gas burners.6
The nuclear fuel cycle is composed of many interesting and
complicated steps, each of which entails its own energetic costs.

The next sections enumerate the parts of the nuclear fuel cycle
and examine the energy input necessary for each step. (These energetic
analyses are rough estimates, but they are the best available
at this time.)

URANIUM MINING AND MILLING

The largest unavoidable energy cost associated with nuclear power
relates to the processes of mining and milling uranium fuel. Variable
grades of uranium ore exist at different mines around the world. A
greater amount of energy is required to extract uranium from a
mine containing a low-grade uranium concentration of 0.1% than
from another mine containing a uranium concentration of 1%—
ten times more. Therefore the specific energy expenditure required
for uranium extraction from the original ore body is largely dependent
upon the ore grade. The energy used to mine the uranium
is fossil fuel—the kind of energy nuclear power is touted as
replacing—with the concurrent production of carbon dioxide.

There is a point at which the concentration of uranium becomes
so low that the energy required to extract and to refine a dilute
uranium ore concentration from the ground is greater than the
amount of electricity generated by the nuclear reactor. For example,
162 tons of natural uranium must be extracted from the earth’s
crust each year to fuel one nuclear power plant. If the uranium is in
granite ore, with a low-grade uranium concentration of 4 grams per
ton of rock (0.0004%), then 40 million tons of granite will need to
be mined. This rock will need to be ground into fine powder and
chemically treated with sulphuric acid and other chemicals to extract
the uranium from the rock (milling). Assuming an extraction
capacity of 50% (an unrealistically high estimate), 80 million tons of
granite will therefore need to be treated. The dimensions of this
mass of rock are one hundred meters high and three kilometers
long. The extraction of uranium from this granite rock would
consume over thirty times the energy generated in the reactor from
the extracted uranium.

The high-grade uranium ores are finite—global high-grade
reserves amount to 3.5 million tons. Given that the current use of
uranium is about 67,000 tons per year, these reserves would supply
fifty more years of nuclear power at current production levels (but
only three years, as noted above, if all the world’s energy needs were
met by nuclear energy). The total of all the uranium reserves, including
high and low grade, is estimated to be approximately 14.4
million tons, but most of these ores would be extremely expensive
to mine, and the ore grades would be too low for electricity production.
Many uranium mines are therefore out of use already.

The mining and milling of uranium is a complex process. The
rock itself must be excavated by bulldozers and shovels and then
transported by truck to the milling plants. All these machines use
diesel oil. Furthermore, the maintenance shops that service this
equipment consume electricity and hence fuel oils. The uraniumbearing
rock is then ground to a powder in electrically powered
mills; the powder is treated with chemicals, usually sulphuric acid;
then several other chemicals (many of which are highly corrosive
and poisonous) are used to convert the uranium to a compound
called yellow cake. Fuel is also needed during this process to create
steam and heated gases, and all the chemicals used in the mills must
be manufactured at other chemical plants.

The specific energy expenditure of the milling process depends
upon which of the two types of available ore are processed. Soft
ores, in which uranium is contained in sandstones, shales, and calcretes,
with uranium concentrations ranging from 10% down to
0.01%, require 2.33 gigajoules per ton of ore extracted (1 gigajoule
= 1 billion joules).  Hard ores, including quartz pebble conglomerates
and granites, with grades that vary from 0.1% to
0.001% or less, require 5.5 gigajoules per ton of ore extracted. In either
case, when the ore grade reaches 0.01% the nuclear fuel cycle
becomes energetically non-productive, because so much energy is
expended to mine and mill the low-grade ores.

MILL TAILINGS

If the mill tailings that remain after the extraction of the uranium
were to be subject to remediation, as they should be, massive quantities
of fossil fuel would be required for this process as well. Millions
of tons of radioactive material that is currently dumped on
the ground, often on native Indian tribal land, emitting radioactive
elements to the air and water, need instead to be buried deeply in
the ground where the uranium originally emanated. This single remediation
process, which should be scrupulously observed, by itself
makes the energetic price of nuclear electricity unreasonable.

These tailings would need to be:

• neutralized with limestone;
• immobilized by mixing them with bentonite to isolate
them from ground water;
• transported and placed back into the mine;
• covered with overburden or soil and then with indigenous
vegetation.

The energy expenditure for adequate remediation is estimated
to be 4.2 gigajoules per metric ton of tailings, four times the 1.06
gigajoules per metric ton expended on the original mining. The
remediation process also involves the extensive use of fossil fuels
and the production of more carbon dioxide.

CONVERSION OF URANIUM TO URANIUM HEXAFLUORIDE

Before uranium can be enriched, it must be converted to uranium
hexafluoride gas, because it is in this form that the fissionable
uranium 235 can be separated from the non-fissionable uranium
238. Uranium hexafluoride is the only uranium compound that is
gaseous at low temperatures and therefore is easy to work with.
The specific energetic requirements for this conversion are 1.478
gigajoules per kilogram of uranium.

URANIUM ENRICHMENT

Enrichment of uranium 235 from 0.7% to 3% is also a very energetic
process. Specific energetic expenditures for enrichment include
construction, operation, and maintenance of the enrichment
plant. Uranium can be enriched using one of two basic methods—
gaseous diffusion and ultracentrifuge—both of which require very
large amounts of energy. (Enrichment by ultracentrifuge has a
lower direct energy cost, but the financial costs of the operation
and maintenance of ultracentrifuge enrichment are much higher
than gaseous diffusion because of the short technical life of the
centrifuges.)

In the United States, enrichment facilities have historically
been located at Paducah, Kentucky, and Portsmouth, Ohio, with a
discarded facility at Oak Ridge, Tennessee. In 2001, however, the
privately owned and operated United States Enrichment Corp.
consolidated its operation in Paducah. The Paducah enrichment
facility uses the electrical output of two dirty, old 1,000 megawatt
coal-fired plants for its operation, contributing significant carbon
dioxide to the atmosphere. It has also recently been revealed by
the U.S. Department of Energy that CFC 114 gas—a compound
that is a potent global warmer and that destroys the stratospheric
ozone layer—leaks unabated from the hundreds of miles of cooling
pipes used in the uranium enrichment operation at Paducah,
Kentucky, and its sister facility in Ohio.

The specific energetic costs of enrichment are measured in
joules per separative work unit (SWU). Averaging the current
world use of the two different processes—30% gaseous diffusion
and 70% ultracentrifuge—the energetic costs are 0.000555 petajoules
per 1,000 SWU. (A petajoule is 1 million billion joules.)

FUEL ELEMENT FABRICATION

The enriched uranium hexafluoride gas is then made into solid
fuel pellets of uranium dioxide, the size of a cigarette filter. These
pellets are packed into a zirconium fuel rod measuring twelve feet
long and half-an-inch thick. A typical 1,000 megawatt reactor
contains 50,000 fuel rods—about one hundred tons of uranium.
Again fossil fuel is used in the fabrication process, and the specific
energy expenditure is 0.00379 petajoules per ton of uranium.

CONSTRUCTION OF THE REACTOR

All nuclear power plants in the United States were constructed between
the years 1980 to 1985 or before, and no new plants have
been ordered since 1978. The construction of a nuclear power
plant requires an immense aggregate of goods and services. Nuclear
technology is a very high-tech process, requiring an extensive
industrial and economic infrastructure. A huge amount of concrete
and steel is used to build a reactor. Furthermore, construction has
become ever more complex because of increased safety concerns
following the meltdowns at Three Mile Island and Chernobyl.
Estimates vary for the energetic costs of reactor construction
from 40 to 120 petajoules. The mean value of 80 petajoules has
been used in the study of Storm van Leeuwen and Smith.

DECOMMISSIONING AND DISMANTLING

When the reactor is finally closed at the end of its working life, the
intensely radioactive products—cobalt 60 and iron 55 formed inside
the reactor vessel from neutron bombardment—must be allowed to
decay considerably before the reactor can even be entered. (Additional
residual contaminating radioactive elements, which are also
very dangerous, include tritium, carbon 14, and calcium 41, among
others.) Thus, these huge, intensely radioactive mausoleums must
be guarded and protected from damage or unwarranted intrusion
for a period of ten to hundred years before the actual process of
dismantling can begin

The steps involved in decommissioning and dismantling include:

• operation and maintenance of the reactor during the safeguarded
period after the final shutdown;
• clean-up of the radioactive parts of the reactor before dismantling;
• demolition of the radioactive components;
• dismantling;
• packaging and permanent disposal of the dismantled
wastes.

After sufficient time is given for the radioactive decay period,
the reactor must be cut apart into small pieces either by humans or
by remote control, and the still-radioactive pieces must be packed
into containers for transportation and final disposal at some distant
location. There is very limited experience available on which to
base energetic cost estimates for decommissioning and dismantling,
because a large nuclear power plant has never actually been
dismantled completely after a long operational lifetime. However,
based on the scarce available data, the energetic debt for this exercise
is estimated to be in the range of 80–160 petajoules, the high
end of the range being the most probable. Traditional coal- or
gas-fired plants can be dismantled in the conventional way as any
building, because they are not radioactive and therefore do not
pose a risk to the public health and safety. The discarded materials,
rubble, and scrap from conventional buildings can be reused. For
comparison: Construction and dismantling of a gas-fired plant require
about 24 petajoules together. The energy requirements of
construction and dismantling of a nuclear power plant may sum up
to about 240 petajoules.

CLEANUP

At the end of its lifetime, the reactor will need to be cleaned of
extensive quantities of accumulated radioactive material called
CRUD (Chalk River Unidentified Deposits, so named because
these materials were first found in the Chalk River reactor).
CRUD is a collection of radioactive elements that come from the
reactor itself—from the cooling system and the highly radioactive
fission and “actinide” elements that have escaped from leaking and
damaged fuel rods. This process, which is separate from decommissioning,
may be energetically very expensive and will need as much
energy debt as 50% of the original energetic construction costs,
which is 20 to 60 petajoules.

COOLING WATER: TRITIUM AND CARBON 14

The water that cools the reactor core becomes heavily contaminated
with tritium, or radioactive hydrogen, and with carbon 14, the longterm
medical and ecological effects of which are not well understood
and are rarely discussed or addressed by the nuclear industry or anyone
else. The radioactive life of tritium is more than 200 years, and
the radioactive life of carbon 14 is 114,600 years. A sustainable energy
system would necessitate a closed loop for tritium and carbon
14, such that they never enter the ecosphere. Theoretically this water
should be stored, immobilized into drying agents or into cement,
and placed in appropriate long-lived containers. Instead, it is
routinely and blithely discharged into seas, rivers, or lakes, from
which people obtain their drinking water. Implementing proper
disposal techniques would require a huge number of waste containers
and massive energy expenditure.

The fact that there is thus far no adequate knowledge of the
long-term biological dangers and because of the absolutely immense
expense associated with sequestering the tritium and carbon
14 from nuclear power plants, there is no adequate estimate of the
energetic costs required to prevent the release of these isotopes.
Hence, the true energetic and economic costs of nuclear power are
presently grossly underestimated.

DISPOSAL OF RADIOACTIVE WASTE

Radioactive waste is classified in vaguely defined categories as low
level, intermediate level, and high level, according to the concentration
and types of radioactive elements. There are five types of
specific containers available to transport these wastes depending
upon the category, which are labelled V1 to V5. The production,
filling, handling, and transport of the radioactive waste in containers
V2 to V4 is estimated to use per ton almost as much energy as
the specific construction energy of the atomic power reactor itself.
The total may sum up to a very large amount as noted previously—
about 20 petajoules.

In addition to handling the reactor wastes, the energetic costs
of nuclear electricity include those associated with interim storage
of irradiated fuel elements. The magnitude of the radiation generated
in a nuclear power plant is almost beyond belief. The original
uranium fuel that is subject to the fission process becomes 1 billion
times more radioactive in the reactor core. A thousand megawatt
nuclear power plant contains as much long-lived radiation as that
produced by the explosion of one thousand Hiroshima-sized bombs.
Every year, one-third of the now-intensely radioactive fuel rods
must be removed from the reactor, because they are so contaminated
with fission products that they hinder the efficiency of the
electricity production.

These rods emit so much radiation that a lethal dose can be acquired
by a person standing in close proximity to a single spent fuel
rod within seconds. But they are also extremely thermally hot and
must therefore be stored for thirty to sixty years in a heavily shielded
building and continually cooled by air or water. If they are not continually
cooled, the zirconium cladding of the rod could become so
hot that it would spontaneously burn, releasing its radioactive inventory.
Finally, after an adequate cooling period, the rods must
eventually be packed into a container by remote control.

Construction of these highly specialized containers uses as
much energy as construction of the original reactor itself,which is
80 gigajoules per metric ton. To make matters worse, spent fuel
packaging is a completely new and relatively untested technology
for which there is no operational data.

TRANSPORTATION OF HIGH-LEVEL AND INTERMEDIATE
WASTE AND LONG-TERM STORAGE FOR 240,000 YEARS

The calculations for this part of the nuclear fuel cycle have not yet
been done. But clearly, huge amounts of fossil fuel will be used to
transport the waste over long distances through many towns and
cities over long periods of time, to prepare an adequate geological
waste storage facility, and to supervise and guard the site for periods
of time almost beyond our comprehension—240,000 years.

Energetic cost assessments provided by the global energy industry
are notoriously and consistently fallacious. For instance, BP-Amoco
in its 2005 world energy supply assessment, simplistically assessed
only the gross electricity production of nuclear power plants, but
failed to incorporate the total energy consumption of the nuclear
fuel chain.

In fact, looking at the energetic costs of the nuclear fuel cycle
just from mining the ore through reactor construction to dismantling
of the reactor, without even assessing the energy costs of storage
and transportation of radioactive waste, the total energy debt
comes to approximately 240 petajoules (24 million billion joules).
The construction and implementation processes involved in a gasfired
plant require only one-tenth that amount—24 petajoules—to
produce the same amount of electricity.

Even utilizing the richest ores available, a nuclear power plant
must operate at ten full-load operating years before it has paid off
its energy debts. And, as noted above, there is only a finite supply
of uranium ore containing reasonable concentrations of uranium
235. When this concentration falls below 0.01%, the costs of energy
production from nuclear power can no longer cover the costs
of extraction of uranium from the earth, at which time, the nuclear
fuel cycle will deliver no net energy; below a certain uranium
content, nuclear power produces less energy than is needed
to build, fuel, and operate the reactor and to repair the environmental
damage.

Setting aside the energetic costs of the whole fuel cycle, and looking
just at the Nuclear Industry’s claim that what transpires in the
nuclear plants is “clean and green,” the following conditions would
have to be met for nuclear power actually to make the substantial
contribution to reducing greenhouse gas emissions that the industry
claims is possible (this analysis assumes 2% or more growth in
global electricity demand):

• All present-day nuclear power plants—441—would have to
be replaced by new ones.
• Half the electricity growth would have to be provided by
nuclear power.
• Half of all the world’s coal fired plants would have to be replaced
by nuclear power plants.

This would mean the construction over the next fifty years of
some 2,000 to 3,000 nuclear reactors of 1,000 megawatt size—one
per week for fifty years! Considering the eight to ten years it takes
to construct a new reactor and the finite supply of uranium fuel,
such an enterprise is simply not viable.

As van Leeuwen and Smith write, “the total known reserves of
uranium . . . [are] so small one must ask oneself why it is that
nuclear power was ever considered as holding promise of very
large amounts of energy.” They cite several possible reasons for this
anomalous situation:

• The nuclear industry originally postulated that fast-neutron
“breeder” reactors would be developed, which would create
fuel as well as use it, in a self-sustaining “closed cycle.”
These reactors have yet to be realized.
• The industry did no calculations and had no conception of
the huge energy costs associated with nuclear power.
• It was not understood for many years exactly how dangerous
radioactive waste was and that long term disposal would
be so intractable.
• It was not understood that uranium ores of less than 0.01%
concentration could never deliver any net energy.
• All environmental damage induced by nuclear power was
assumed to be left for future generations to rectify.

With the knowledge about these topics that is now available,
however, clearly the nuclear industry is running a public relations
scam of massive proportions.

Disagreements exist about availability of uranium for the intended
“nuclear renaissance.” What differentiates the analysis in this
chapter by Storm van Leeuwen and Smith is that no association or
study group including the World Nuclear Association, has previously
analyzed the uranium ore grade–energy relationship.

While highly-enriched military uranium is currently being
mixed with low-enriched uranium for nuclear reactors in the
United States, this amounts to only six years of the present annual
natural uranium demand. There are no indications of new large
rich deposits of uranium ore, and the currently known recoverable
resources would supply 2,500 “renaissance” reactors for only eight
years.

Some argue that reprocessing plutonium for reactor fuel will
take care of deficient uranium supplies. Reprocessing is dangerous,
extremely costly, and contributes to weapons proliferation.

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C 2006 by Helen Caldicott. This excerpt is taken from Dr. Helen Caldicott's
book  Nuclear Power Is Not the Answer (The New Press, September 20, 2006).
Published with the permission of The New Press and available at good book
stores everywhere.

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Comment from RDCLEM

"This article is extremely riddled with incorrect information. There are too many false facts in this article for me to even begin to comment on them. Ms. Caldicott needs to bone up a little bit more before writing about something that is obvioulsy not within her field of expertise."