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Frequently Asked Questions
Prime Minister John Howard tells us that any nuclear inquiry necessarily needs to contain experts from the nuclear industry. However, its the details they leave out that are of grave importance to many Australians. We try to fill in the details of the many aspects overlooked by pro-nuclear pundits.
You can download this information in pdf fact sheets [here]
What is uranium?
Where could uranium be mined in Queensland?
How is uranium mined?
What is underground mining?
What is In-situ leach mining?
What is open cut mining?
What does uranium milling entail?
What is a tailings dam?
What happens to the site after mining has ceased?
What are the risks to miners?
Does uranium benefit indigenous people?
Why is uranium mined? What is it used for?
What is uranium?
Uranium is the heaviest of all
minerals. It was first isolated in
1841, although its origin is in the
formation of the universe. The
earth’s crust contains an average
of about 3 ppm (= 3 grams per tonne) uranium, and
seawater approximately 3 ppb (= 3 mg/t) (WISE 2006).
The amount of uranium in ore is always quite small,
averaging 0.3% in Australia but as high as 15% in Canada.
So the ore must be milled to concentrate the uranium.
The resulting product, uranium oxide (U308) is called ‘yellowcake’ because it is sometimes that colour.
Naturally occurring uranium contains three main isotopes, all of which are radioactive: U238, U235, and U234, although 99% of the U found in yellowcake is U238. Because yellowcake contains the three commercially useful isotopes, it is radioactive. Uranium isotopes remain radioactive for a long time – indeed millions of years: U238 has a half-life (the time it takes for it to lose half its radioactivity) of 4.5 billion years, U235 704 million years, and U234 245 thousand years.
Uranium occurs naturally all over the world and
as a result contributes to what is called ‘background’ radiation. Radon is a radioactive gas released from the
decay of uranium. Uranium and thorium are the main sources of background radiation, which averages 2mSv
in Australia (ARPANSA 2003).
Where could uranium be mined in Queensland?
In Australia three kinds of mining process are used to extract uranium: underground (as used at Olympic Dam), surface (open pit, as used at Mary Kathleen), or solution/in-situ leach, (as used at Beverley). All pose risks to environment and human health, especially wit respect to water.
Tunnel mining, despite being less visible than other
types of mining, poses risk to both human health
and environment. Besides the obvious risk
regarding collapse and air quality in underground
operations, uranium mines present a dangerous
scenario for workers due to exposure to radon gas
and uranium dust. Subsidence, pot holes, fissure
an other surface openings occur and disruption and
contamination of groundwater and acid mine
drainage also occur.
The most environmentally visible of the types of
mining used for uranium, open cut is basically a
massive pit cut into the surface of the earth
extracting everything in it’s path. Open cut
mining also allows more dust and particles to escape
into the local atmosphere, although their outdoors
nature may reduce the exposure to radon gas of workers.
Open cut mines are notoriously difficult to rehabilitate
due to the sheer quantity of earth removed.
The most contentious type of uranium mining, in-situ leach (ISL) involves injecting huge quantities of water and sulphuric acid into the deposit or the aquifer in which the
deposit occurs, and sucking the resulting slurry out for separation. The potential for ground and surface water contamination is far greater than other types of mining, as blockages in pipes can cause leachate to flow out of control (as occurred during a trial at Honeymoon, SA). The pumping process may also release large quantities of radon gas into the atmosphere, risking workers. However, the risk to workers inhaling uranium dust may be less.
What happens after the mining ceases?
Uranium mines remain dangerous after closure. One of the
enduring problems everywhere is the clean up afterwards.
Mining companies rarely seems to save enough money for the
task. US state agency representatives estimated in 2004 that
an open pit copper mine in New Mexico would cost more than
US$800m to clean up. In July 2005 Energy Resources
Australia (ERA), operators of the NT’s Ranger mine, revealed
in their half-yearly report that they had put aside just $41m
to remediate the site which is surrounded by Kakadu National
Park. ERA say it will cost closer to $176m to clean up the site
when the mine closes in 2008, the rest may have to be met
by the state.
When Mary Kathleen mine in Queensland closed in 1982, it had produced about 3500 times more rock waste than it turned into yellowcake and left a massive conical hole 4km wide at the top and 250m deep. Shortages in the MK remediation fund meant that they took shortcuts when sealing in tailings. Instead of using clay, they used a combination of
clay and radioactive rock from the mine site itself. In 2004, State Member for Mt Isa, Tony
McGrady expressed concern that people were swimming in Mary Kathleen tailings
dam, risking radiation contamination. FoEB 2006
What does uranium milling entail?
Left: tailings dams at Olympic Dam, SA.
After extraction, uranium must be separated from the
other minerals in the deposit. This is done by crushing and
leaching the rock using water and (usually) sulfuric acid.
The leaching process also separates out other minerals
including molybdenum, vanadium, selenium, iron, lead and
arsenic, requiring a second separation to remove the
uranium.
This process uses enormous amounts of water which is
contaminated with acid and the unwanted minerals and
leftover uranium, and containing long lived decay products
such as thorium230 and radium226. It is left in tailings
dams, ostensibly because the waste is safer and less likely
to dust disperse when inundated. The sludge that tailing
water covers is 85% as radioactive as the uranium
extracted and it continues to release radon. Tailings dams
all over the world have had leakage problems and there are
many documented instances of increased exposure to
radiation in people living downstream from these tailings
dams through consuming contaminated water, fish and
crops. In 2004 Olympic Dam uranium mine reported a leak
from their tailings dams system that had gone unnoticed
for several years. In addition, local wildlife have been
killed by drinking the tailings water.
After milling, uranium is transported out of Australia for enrichment into a state suitable for weapons manufacture and energy use.
Risks to miners:
“Over the years the permitted
levels of radiation exposure for
workers and the public have
dropped dramatically as
research, particularly from
radiation biologists, indicates
harmful effects still exist at much
lower exposure levels. For workers,
the permitted dose was set at 500
millisieverts per year in 1934, 150
mSv in 1950, 50 mSv in 1956, and
20 mSv (averaged over five years)
in 1991. The limit for members of
the public is just 1 mSv....the
European Committee on Radiation
Risk, comprising 30 independent
scientists, released a report which
concluded that the total ermissible
dose to members of the public from
all human practices should be
reduced to no more than 0.1 mSv (a
ten-fold reduction), with a limit of 5 mSv for nuclear workers
(a four-fold reduction).” (2006: FoEA. The Push to Expand
Uranium Mining)
In March 2004 workers at ERA’s Ranger mine in the Northern
Territory were accidentally poisoned with radioactive water,
the extent of which they only discovered after reading the
newspapers, not from their employers. Workers drank and
bathed in the radioactive water. A Commonwealth-appointed
scientist Arthur Johnston commented to media that ERA had
become complacent about radiation dangers at the Ranger
mine and did not provide enough protection for
workers.
Indigenous rights and uranium mining
The indigenous people of
Australia are under pressure from
mining companies to permit
mining on their sacred lands,
sometimes in exchange for basic
services like school and hospital
that they should already have and
royalties are often an enticement
in areas where poverty and lack
of services prevail due
government neglect. These
conflicts can cause rifts in the
community.
The health and environmental
effects are felt in many mining
communities worldwide to
varying degrees, the Navajo
homelands region of the US being
a notable example where residents experience lung cancer rates and over half of
groundwater is contaminated by defunct uranium mines.
The effect on the community has been so dire than in
2005 the Navajo elders signed the first ever tribal law banning uranium mining (SRIC 2005).
Besides the resumption and contamination of indigenous
lands the greed of mining companies and governments
can lead to corruption and worse. In 2005 a Gansu
(China) uranium mine employee went missing after
attempting to report the severe radiation poisoning
affecting local residents. “residents near and
downstream of the plant have begun suffering a high
incidence of cancerous tumors, leukemia, birth defects,
miscarriages and other unusual afflictions. ...Local
medical workers report that nearly half of all deaths in
the area are from some form of cancer, but patients’
case histories are routinely altered because of “state
secrets” concerns” (HRIC 2005).
Why is uranium mined? What is it used for?
Uses include: colouring glass, counterweights in
elevators and airplanes, ballast for space missile reentry,
smoke detectors, food ‘sterilisation’, industrial filling
instruments, reflective paint on clock faces, xrays,
medical treatments, nuclear power and nuclear weapons.
All of these uses can be replaced with other technology.
Indeed a 2006 report showed that in one seemingly vital
use, in smoke alarms, light activated alarms worked
faster than radioactive alarms.
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Nuclear Free Queensland Fact Sheets