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Nuclear Fuel Cycle
Please also see RCW's Model
Nuclear Inventory; and
RCW's fact sheet on Nuclear Energy, available in HTML
and PDF.
New resources on nuclear fuel cycle politics
and policy available from RCW's First
Committee Monitor,
written by Michael Spies, Lawyers'
Committee on Nuclear Policy:
Week
1: 8-12 October 2007
Week
2: 15-19 October 2007
Final
Edition: October 2007
The
Nuclear Fuel Cycle
The Basic
Ingredients
First, you need mildly-enriched uranium.
There are 92 naturally occurring elements but only
one, uranium, has become the key to the operation of the nuclear
fuel cycle. Natural uranium consists of three isotopes: uranium-238,
uranium-235, and uranium-234.
Uranium isotopes are radioactive.
When uranium is mined from the earth it contains only about 0.7%
uranium-235. Industrial processes enrich uranium by concentrating
the amount of U-235 to 3% or more for use as reactor fuel. Uranium
with more than 20% U-235 is called highly-enriched uranium (HEU).
An atom can be pictured as a small universe with a nucleus at its
centre and electrons orbiting around it. The nucleus contains protons
and neutrons. Each electron has a negative charge and each proton
a positive charge; since there are an equal number of protons and
electrons the atom the atom is neutral. Atoms of the same element
have the same number of protons (the atomic number). However, the
same element can have atoms with varying numbers of neutrons in
their nucleus giving atomic species of different atomic weights
known as nuclides. Thus for the key element uranium, the nucleus
of uranium-235 has 143 neutrons and 92 protons and uranium-238 has
146 neutrons and 92 protons.
The nuclei of radioactive elements are unstable, meaning they are
transformed into other elements, typically by emitting particles
(and sometimes by absorbing particles). This process, known as radioactive
decay, generally results in the emission of alpha
or beta particles from the nucleus. It is often also accompanied
by emission of gamma radiation,
which is electromagnetic radiation, like X-rays. As radioactive
atoms decay, alpha, beta and gamma rays are emitted. Alpha rays
are heavy positively charged particles travelling at high speed
(several kilometres a second). These rays emanate from heavy elements
such as uranium, plutonium and americium. Beta rays are negatively
charged electrons seven thousand times lighter than alpha particles.
Gamma rays are electromagnetic radiation which emanates from most
though not all radionuclides.
These three kinds of radiation have very different properties in
some respects but are all ionizing
radiation--each is energetic enough to break chemical bonds,
thereby possessing the ability to damage or destroy living cells.
Uranium-238, the most prevalent
isotope in uranium ore, has a half-life of about 4.5 billion years;
that is, half the atoms in any sample will decay in that amount
of time. Uranium-238 decays by alpha emission into thorium-234,
which itself decays by beta emission to protactinium-234, which
decays by beta emission to uranium-234, and so on. The various decay
products, (sometimes referred to as "progeny" or "daughters") form
a series starting at uranium-238. After several more alpha and beta
decays, the series ends with the stable isotope lead-206. (Source:
Institute for
Environment and Energy Studies)
Uranium Mining
Uranium is the principal fuel for nuclear reactors and the main
raw material for nuclear weapons. Both radioactive U-235 and stable
U-238 are found in naturally occuring uranium deposits. Traditionally,
uranium has been extracted from underground and open pit mines.
Over half of the world's production of uranium from mines is in
Canada and Australia. Uranium is also mined in China, the Czech
Republic, France, Gabon, India, Kazakhstan, Namibia, Niger, Russia,
South Africa, Spain, Ukraine, the United States, and Uzbekistan.
Natural uranium has to be mined from the earth like
any other natural element. Yet, unlike other natural elements, uranium
is radioactive. As a result, every aspect of uranium production,
from mining to transportation, has damaging environmental and health
effects.
Uranium mining has scarred the landscape and affected
areas in 16 countries with millions of tons of dangerous
dirt called tailings. Uranium mining on indigenous and tribal
peoples' lands has devastated local communities and environments
in North America, Australia, Africa, and Asia. For every ton
of uranium oxide produced, thousands of tons of wastes, or tailings,
are left behind. Often the tailings are simply dumped on the land
near the mine and left to the effects of the elements. Wind carries
radon gas and radioactive dust from these tailings for many miles.
Contaminated rainwater enters the soil, the watershed and, eventually,
the food chain, endangering health. Indigenous peoples' lands have
also been used to dump radioactive wastes and to test (explode)
nuclear bombs both above-ground and below-ground, resulting
in massive radioactive contamination.
In Northern Saskatchewan, Canada,
where the world's largest and most concentrated known uranium reserves
are located, routine releases and accidental spills of contaminated
water from mining and milling operations have poisoned major fisheries
and threatened the health and livelihood of indigenous communities.
In Niger and Namibia, uranium
tailings are simply dumped on the desert sand, contaminating the
air, food, and drinking water of nomadic tribes.
In the Southwestern U.S., mining
wastes abandoned on indigenous peoples' land have damaged the health
of their communities. It is little known that the second worst nuclear
disaster in US history was the spilling of uranium mine tailings
in the Rio Puerco River in New Mexico in the 1980s.
Dineh (Navajo) and other uranium
miners in the U.S. have contracted cancers at a much higher rate
than the general population (including a lung cancer incidence forty
times greater than normally expected). They were not told about
the dangers of radioactivity.
Tibetan people
have been, without their knowledge, radiation-tolerance test victims
at sites of Chinese-operated uranium mines and waste dumps.
(Source: Plutonium
Free Future; RCW's Fact
Sheet on Uranium Mining)
Uranium
Enrichment
In order to be used in a reactor, the uranium must be enriched,
increasing the percentage of radioactive U-235 in the sample. For
typical civilian power plants the uranium must be enriched so that
it contains 3% - 5% of uranium-235.
After mining the uranium mineral is refined to uranium
oxide, called yellowcake. This natural uranium is processed and
then enriched. Numerous technologies have been developed to enrich
uranium, such as gaseous-diffusion, centrifuges, and electromagnetic
separation. All of these technologies require a large initial investment
and large amounts of energy to operate.
Yellowcake has two forms of uranium: uranium-235
and uranium-238. Uranium-235 fissions (splits) readily.
Its concentration in yellowcake is only 0.7%. For the common nuclear
reactor (light-water) yellowcake is enriched to 3%
uranium-235. To make bomb-grade fuel yellowcake is enriched
to 90%. Before enrichment, yellowcake is converted to a volatile
material called "hex" (uranium hexafluoride).
In the diffusion process hex vapour
passes through thousands of membranes along a two kilometre tunnel.
In the other process the vapour passes through hundreds of small
ultra-high-speed centrifuges. Centrifuge plants are compact and
so readily concealed. They allow a country possessing a plant to
switch quickly from the production of reactor-grade to bomb-grade
fuel.
(Source: The
Sustainable Energy and Anti-Uranium Service, Inc.)
Reprocessing
Reprocessing is probably the dirtiest operation in the nuclear fuel
cycle. Reprocessing is also the option that generates the largest
amount of radioactive waste. The most dangerous of this waste is
called high-level waste -- a liquid waste stream carrying chemicals
used in reprocessing along with many radioactive isotopes from the
spent fuel or other material. This high-level waste would be added
to over 30 million gallons of liquid waste from past reprocessing
already stored in underground tanks at SRS. Some of these tanks
have leaked, and storage of the waste in this form poses risks of
fire or explosion resulting from chemical reactions inside the tanks.
Moreover, in January 1998, SRS officials acknowledged -- after over
a decade of warnings and a half billion dollars in expenses -- that
one of the techniques intended to help remove waste from the tanks
is unsafe. A replacement technology may not be ready until 2005.
Reprocessing is a chemical reaction, which separates plutonium and
uranium from fuel which has been irradiated in reactors. The plutonium
is important for weapons production, while the uranium is basically
a byproduct that can be recycled as fuel. Because reprocessing is
also part of the civilian nuclear fuel cycle, reprocessing is a
key link between civilian nuclear power and nuclear weapons production.
Thus, the existence of a reprocessing plant is what gives a country
the ability to produce plutonium for nuclear weapons. Therefore,
any country that has operating reprocessing plants can be classified
as a potential nuclear-weapons power (Makkhijani, Hu, and Yih, 1995,
p 47-48).
Reprocessing is also extremely costly. The overall costs of spent
fuel management and disposal ranges from approximately $130 billion
to $240 billion for commercial reprocessing (Makhijani and Saleska,
The Nuclear Power
Deception: US nuclear mythology from electricity "too cheap to meter"
to "inherently safe" reactors, 1999, p. 9). The countries
that have commercial reprocessing plants include UK, France, USA,
Russian Federation, Japan, and India. All five of the reprocessing
programs are governmentally owned or subsidized. ( Makhijani and
Saleska, p. 122). The countries with military plutonium separation
sites include USA, Russian Federation, UK, France, China, India,
Israel, and Pakistan.
Mixed Oxide Fuel (MOX)
MOX is part of the nuclear fuel cycle which is used in the civilian
branch of nuclear industry. Plutonium is converted into uranium-plutonium
oxide fuel (called Mixed Oxide Fuel) to use it in existing commercial
reactors or in new reactors. Used nuclear fuel can then either
be disposed of as waste or recycled. A nuclear reactor
uses enriched uranium fuel to produce heat, which in turn generates
electricity. MOX fuel is manufactured by blending uranium
and plutonium powders to include 3-10% plutonium.
The conversion of MOX into weapons-grade plutonium metal is feasible
(Kuppers and Sailer, 1994, p85). This use creates a new commercial
- military link creating dual-use reactors. Companies such as BNFL
are hiding this direct connection by claiming to partially destroy
(or "burn") rather than create military plutonium (Makhijani and
Saleska, p10, 1999).
The use of MOX has huge setbacks due to the high cost
of creating MOX fuel. In addition to a serious security liability
the majority of independent studies done in the US have indicated
that plutonium is not an economically viable energy resource. These
studies have found that it is cheaper to use uranium fuel instead
of MOX fuel. Uranium has turned out to be far more plentiful and
far cheaper than predicted at the dawn of the nuclear era (Makhijani
and Saleska, 1999, p 166).
Furthermore, there are inherent conflicts of interests. The corporations
involved in the disposition of plutonium by using it as MOX fuel
are the very same corporations that have a stake in the commercial
production of plutonium (Makhijani and Saleska, 1999, p175). This
is clearly indicated by BNFL
which both creates and cleans up nuclear materials. Westinghouse
(BNFL owned) runs the majority of nuclear power plants in
the US while Bechtel Corporation is
involved in massive nuclear clean up in the US.
Nuclear
Power Plants and their side effects
Inside a Nuclear Power Plant...
1. The yellowcake is broken into small pieces and put into
long metal rods. The rods are collected into bundles.
2. The energy released from these bundles during fission
is used to heat water, turning it into steam.
3. At this point, nuclear power plants function much the
same as traditional fossil fuel plants. The force of the steam moves
a turbine that, in turn, powers a generator that creates
electricity. All nuclear reactors rely on steam in this manner.
There are different major types of reactors that create this steam
in slightly different ways, such as: Boiling Water Reactors, Pressurized
Water Reactors, CANDU reactors (Canada Deuterium Uranium, a type
of pressurized heavy water reactor), and LMFBR’s (Liquid-Metal
Fast-Breeder Reactor). For more information about the different
types of reactors please visit http://hyperphysics.phy-astr.gsu.edu/hbase/nucene/reactor.html
or http://www.chemcases.com/2003version/nuclear/nc-10.htm
4. The rate of fission is determined by the
number of neutrons bombarding the uranium sample. In order to adjust
the rate at which the steam is produced, control rods (which
absorb neutrons) are placed within the bundles. More energy will
be created the further the control rods are raised out of the bundles,
since fewer "bombarding" neutrons will be absorbed. If the operator
wishes to slow or stop fission, the control rods will be fully submerged
in the bundles.
Side Effects of Nuclear Power Plants
Nuclear/radioactive waste consists
of the broken down uranium fuel used during fission, as well as
all the machinery used in the process and the nuclear plant itself.
Since so much high intensity energy is released during fission,
everything that has come into contact with that energy becomes embedded
with radioactive elements. The break down of uranium creates elements
such as cesium, strontium, and plutonium. Though not useful to the
production of more nuclear energy, these elements are highly radioactive.
The Plutonium Free
Future project assessed that by the year 2000, the nuclear industry
had "created 201,000 tons of highly radioactive irradiated (used)
fuel rods. The plutonium in the waste will remain radioactive for
up to 240,000 years (12,000 generations) or more."
This means that any living thing coming into contact with plutonium
waste during this long period of time will be exposed to potentially
harmful radiation, so, "for that entire time it must be isolated
from all living organisms and from the water, land and air upon
which they depend." However, there is no long-term solution for
its disposal or storage. Short-term solutions do not address the
grave health and environmental effects of nuclear waste that last
for hundreds of thousands of years."
Toxic and nonradiological hazards,
such as acids, solvents, nitrates, oils, heavy metals, fluorides,
explosives, mercury, beryllium, and asbestos, are also products
of the nuclear weapon legacy that have negatively affected public
health and the environment.
For more information about the types of nuclear waste,
please visit http://www.nirs.org/factsheets/llwfct.htm
or http://www.nirs.org/factsheets/hlwfcst.htm
Nuclear waste is particularly devastating since there
is no long-term solution for its disposal or storage. Short-term
solutions do not address the grave health and environmental effects
of nuclear waste that last for for hundreds of thousands of years.
Generally, nuclear waste is dumped in low-population areas of the
world ranging from Australia to Kentucky. To see a map of U.S. states
that have agreed to be nuclear waste disposal sites see: http://www.hsrd.ornl.gov/nrc/rulemaking.htm
Dangers of Nuclear Reactors. As if
the problems and dangers posed by nuclear waste weren’t enough,
the very existence of nuclear reactors creates a serious threat
to our environment and our health. As stated in A Race Against
Time, the 1978 Report on Nuclear Power by the Royal Commission
on Electric Power Planning, “when we talk about the safety
of a nuclear reactor, we are referring essentially to how effectively
the fantastic amount of radioactivity contained in the reactor core
can be prevented from escaping into the ground and atmosphere in
the event of major malfunctions” (http://www.ccnr.org).
Yet, as we have already seen in the past few decades, major and
minor malfunctions in nuclear reactors can have catastrophic consequences.
Here are two examples of recent nuclear reactor malfunctions.
Chernobyl. On April 25th and 26th 1986, the
world experienced the worst nuclear power accident in the history
of atomic technology. During a routine test of Reactor Four, the
reactor experienced two explosions within two minutes of each other
as a result of mechanical flaws and operational failures. As a result,
at least five percent of the radioactive reactor core was released
into the atmosphere, first blanketing Northern Europe, then the
rest of the world. The dire health and environmental consequences
are still being revealed to this day. For more information about
the Chernobyl accident please see: http://www.wagingpeace.org/menu/action/urgent-actions/chernobyl/
Three Mile Island. Due to mechanical and operational
failures, this nuclear power plant on Pennsylvania’s Susquehanna
River experienced a partial meltdown on March 28, 1979. The extent
of the damage and the amount of radioactivity released into the
environment during that period is still disputed in the scientific
community. Even so, the events at Three Mile Island illustrate how
quickly a functioning nuclear reactor can deteriorate into a near
meltdown. It also reveals the life threatening consequences of basic
human error on the part of even the best-trained nuclear technicians.
For more information about the chronology and aftermath of Three
Mile Island, please see http://www.washingtonpost.com/wp-srv/national/longterm/tmi/tmi.htm,
or http://www.pbs.org/wgbh/amex/three/sfeature/index.html
For more information on the dangers of nuclear reactors, please
visit http://www.ccnr.org/#accident
For more information on the ramifications of nuclear energy, please
visit: http://www.thebulletin.org/article.php?art_ofn=ja00abrahamson
Weaponization
There are correlations between nuclear energy technology
and nuclear weapons technology. Not all states developing nuclear
energy technology have the intention to use that technology for
weapons. Yet, once the technology and machinery for creating nuclear
energy are gained, it is possible to begin developing weapons technology.
Uranium for civilian use needs to be enriched to >5%. Military
use uranium needs to be enriched to >90%. (http://www.ieer.org)
While this discrepancy is great, a person or State with the technology
to enrich uranium for energy has the potential to move towards weapons
development.
Another relationship between nuclear energy and nuclear weapons
is the ability to “recycle” spent atomic fuel, in the
form of plutonium, into weapons technology. Uranium can produce
plutonium during fission.
During the operation of a reactor, some uranium-238 is converted
to plutonium-239. Periodically spent-fuel is removed from reactors
and after storing for a year or more it can be treated in a reprocessing
plant to recover the plutonium, the essential ingredient of the
nuclear bomb. Only 8 kilograms of plutonium (the size of a large
orange) is needed for an explosion.
While other dangerous elements also occur, plutonium is important
in that it can be used in nuclear weapons. “If the nuclear
power reactor continues operating for a total of 30 years, it will
have produced enough plutonium for at least 1200 bombs” (http://www.nirs.org/factsheets/PLUTBOMB.htm).
For more information on “recycling” atomic fuel, please
see http://www.nirs.org/factsheets.
See Reaching Critical Will's Model
Nuclear Inventory for a complete view of nuclear weapon and
nuclear technology holdings and developments.
Resources
For additional information, please see:
777 UN Plaza - 6th Floor - New York, NY - 10017 - Ph: 212.682.1265 - Fax: 212.286.8211 - info@reachingcriticalwill.org
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