TL: URANIUM MINING - THE NUCLEAR NIGHTMARE BEGINS
SO: Karen Richardson, Greenpeace International, (GP)
DT: February 15, 1996
Keywords: environment nuclear power ukraine republics
accidents problems chernobyl /
 
Uranium is the principal fuel most used in nuclear power
plants.   Before uranium can be made suitable for use in a
nuclear reactor,  it must be mined from the earth and go
through milling, conversion and enrichment processes.
 
MINING
 
There are two main types of uranium mine.
1. Open-Pit: This is used to mine `near-surface' deposits
2. Underground: This is used to mine deposits too deep for
open pit mining
 
The uranium is extracted either by leaching: when the
uranium is dissolved in acid solution which is injected into
the rock, and is then pumped to the surface. However, not
all the acid can be collected and consequently leaks to the
environment.  Or by traditional rock blasting methods.
 
Uranium can occur in association with other minerals such as
gold and copper and is often mined as a by-product of these
other materials.
 
Uranium is a radioactive element.  It decays into a series
of other radioactive elements, known as "daughter products"
until it ends up as a stable form of lead.  As a
consequence of the various radioactive forms uranium goes
through, the uranium ore in deposits contains many
radioactive elements, some of which are particularly
hazardous.
 
One of the major dangers of uranium is that it produces
radium and radon gas  (a daughter product of radium).
When radon gas is inhaled it can cause lung cancer, while
the radium can find its way into people, via food and water
pathways, to cause other types of cancer. Uranium is also
dangerous as a toxic heavy metal.
 
The release of radon gas creates additional dangers,
particularly in underground mining operations. Good
ventilation will protect the workers in underground mines,
but increases environmental contamination and the danger to
surface workers.   However, if there is no ventilation the
health risks to the underground workers are greatly
increased. While open pit mining leads to direct releases of
radon to the surrounding environment.
 
Both underground and open pit mining involve the removal of
massive quantities of the raw material from the earth.   In
most uranium mines the percentage of uranium metal in the
rock that is mined is very low in comparison to other mining
industries - it is only between 1-0.1 %.
 
Many of the mining areas are on land that was previously
occupied by indigenous peoples, for example the Aborogines
in Australia.  By mining in "remote" regions on land
occupied by  indigenous communities the nuclear industry
attempts to avoid the true health and environmental costs of
uranium mining.
 
MILLING
 
Generally this process increases the concentration of
uranium from 1% to 75%.  The ore is ground down and then
dissolved in concentrated sulphuric acid.  The liquid is
then allowed to settle in large open air ponds or lakes
known as tailings dams.  The concentrated ore produced from
this liquid is known as 'yellow-cake'.
 
Approximately 80% of the original radioactivity from the ore
remains behind in the tailings dams where the once stable,
and much safer, hard rock is now in a looser form and open
to the wind and weather conditions, from which radon gas and
radioactive dust can escape almost unhindered. This means
that uranium mining  and milling are dangerous, not only for
the workers, but also for people living in the surrounding
area.
 
In addition to the radioactive hazards, "tailings" may
contain chemically hazardous substances, including cyanide,
arsenic. lead and mercury, which were previously held
harmlessly in the rock, are now able to get into the
environment by seepage, leaching and blown dust.
 
There have been massive accidental releases into the
environment from tailings dams.  One of the worst accidents
was in the US, where a dam broke, releasing 100 million
gallons of liquid mill waste and an estimated 1,100 tons of
solid waste into the Rio Puerco river.  In Australia, a
similar dam failure resulted in severe contamination of the
East Finniss river, virtually wiping out plant and fish life
in the river and on its banks.
 
Nearly half the radon gas in the original uranium ore is
liberated during mining and the other half during milling.
The concentrations of the gas and radioactive dust mean that
the mill workers get radiation doses second only to the
miners.
 
 
After mining and milling the uranium goes through a number
of other processes where further contamination takes place
and more waste is created.  Uranium has to be "enriched"
before it can be used as a fuel for reactors.  This process
can be use to increase the percentage of uranium-235 in the
ore from 0.7% to between 2%-80%, depending on what type of
reactor the uranium will be used in.  The enrichment process
leads to further wastes, leaving behind large amounts of
depleted uranium-235.
 
In terms of bulk, uranium mining leaves behind the largest
amount of waste of the whole nuclear fuel cycle.
 
MAIN PRODUCERS OF URANIUM - 1992 FIGURES
(IN URANIUM OXIDE)
 
Canada                      10,748 tonnes
CIS                               9,000 tonnes
Nigeria                          3,420 tonnes
France                          3,396 tonnes
Australia                       2,752 tonnes
USA                              2,560 tonnes
 
(OFFICIAL AUSTRIAN GOVERNMENT FIGURES)