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Quantities
needed to fuel one 1000MW reactor for one year...
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Uranium mine
at Roxby Downs |
1.
Mining and Milling
Uranium is taken from the earth like any other metal, blasted
and dug from open pit or underground mines (Ranger is open cut;
Olympic Dam is part open cut and part underground. In some parts
of the world, it is leached out of the ground by injecting strong
acid or alkaline solutions into the groundwater, a process known
as In-Situ Leach (ISL) or solution mining.
Uranium
needs to go through a complex milling process to extract it
from the host rock before it can be sold in a form known as
yellowcake, chemical symbol U3O8.
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146,000
tonnes ore
(Average grade 0.11% uranium)
produces
~150
tonnes of
Yellowcake (U3O8)
if 93% of the uranium is recovered
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Ranger tailings dam |
2.
Tailings
Waste
Most
uranium ore grades are very low - generally much less than one
percent of the rock is actually uranum. Therefore for every tonne
of uranium produced, thousands of tonnes of finely powdered radioactive
rock are left over. This waste, which contains huge quantities
of carcinogenic alpha emitters is left at the minesites for future
generations to deal with.
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+
145,850
tonnes of tailings
(finely milled radioactive sand)
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Cogema enrichment plant |
3.
Refining and Enrichment
Yellowcake from mines in Australia arrives at overseas enrichment
plants in Japan, France, the UK, Russia or the USA for processing.
This usually involves converting the uranium oxide into uranium
hexaflouride (UF6), a dangerous radioactive gas. The gas is
then either centrifuged or diffused through fine screeens to
be enriched in the 'fissile' U235 which will sustain chain reactions.
Once enriched, the uranium gains military value. Depending on
the level of enrichment (anything from 3%-90%), the uranium
can then be used as fuel for power, research or military reactors
or nuclear weapons.
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The
Yellowcake is processed to produce
33
tonnes enriched UF6
(uranium hexaflouride)
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Depleted uranium bullet |
4.
Depleted Uranium
The leftover material from the enrichment process, composed mostly
of the 238 isotope, is known as depleted
uranium. DU is now a weapon of choice of the US military.
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+
117
tonnes depleted uranium
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Nuclear fuel rod |
5.
Fuel Fabrication
The enriched uranium is then converted into a solid uranium dioxide
(UO2) powder and pressed into small pellets. These are mounted
into fuel assemblies for use in nuclear power stations. |
The
UF6 is converted into
33
tonnes UO2 fuel
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Calvert Cliffs Nuclear Power Station |
6.
Nuclear Power Plant
Nuclear power plants today supply up to 7% of the world's primary
electricity. They can be two or three times more expensive to
run than coal-fired power plants, and have themselves become
a kind of radioactive waste by the time they are closed down.
Essentially
each reactor is harnessing the energy of an atomic bomb in slow
motion. The fuel rods shed huge amounts of energy as the atoms
within them fall apart, and the air or water cooling systems
designed to keep the reactors from exploding can be used to
drive turbines and generate electricity. Nuclear power stations
as we know them originated as a way of providing an acceptable
public use for technology designed to build atomic weapons -
the power generation aspect was literally an afterthought.
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33
tonnes of fuel will power a 1000MW nuclear reactor for one
year.
At
the end of the year you have
33
tonnes of spent fuel
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Interim storage |
7.
Interim Storage
After use, spent nuclear fuel is stored on-site in pools or halls
close to the reactor buildings while it is too hot (both in terms
of radiation and radiant heat) to do anything with. Most of the
world's high level nuclear waste is in interim storage. |
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Moving nuclear fuel |
8.
Transportation
One of the most hazardous operations of the nuclear fuel chain
is moving spent fuel from one location to another. Most commonly,
fuel is moving out of interim storage by road or rail to a reprocessing
plant. |
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Reprocessing at Savannah River |
9.
Fuel Reprocessing
Reprocessing is a military technology for dissolving spent nuclear
fuel in nitric acid to extract the plutonium that was created
as a result of the fuel being 'burned'. Originally only of use
in nuclear weapons, the nuclear powers are now experimenting
with mixed-oxide (MOX) reactors that burn blended uranium/plutonium
fuel. The reason? To get rid of the excess plutonium created
in weapons programmes. Most of the world's commercial reprocessing
(80% or so) is undertaken at Cogema's facilities at La Hague.
Most of the rest is done at BNFL's Sellafield plant.
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33
tonnes of spent nuclear fuel contains
31.5
tonnes depleted uranium
1.2
tonnes fission products & actinides
300
kilograms plutonium
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Sea-launched missile |
10.
Nuclear Weapons
There are still more than 36,000 nuclear weapons in the arsenals
of the declared nuclear powers. The massive security apparatus
needed to keep this atomic hairtrigger from going off has become
a self-perpetuating nightmare, for it demands exotic levels of
secrecy and drains billions of dollars from the productive economy.
In 1996, the World Court found the intention to use nuclear weapons
was actually illegal under international law (since they are tools
of genocide) and this has given the worldwide abolition campaign
added momentum. |
300kg
of plutonium is enough for
60
NUCLEAR
WEAPONS
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Nuclear waste castors |
11.
Nuclear Waste
An assortment of spent fuel rods, military waste, process chemicals
and heavy metals make up the side of the nuclear industry that
our government is quite happy to leave unmentioned when it approves
uranium mines. The nuclear industry was initiated without any
coherent waste management strategies: public awareness of this
mountain of waste is now the most significant impediment to
further nuclear expansion.
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