The Range of Environmental Concerns - Mining and the Environment: From Ore to Metal - page 560

evaporated and the contained metals are retained in secure storage. During the operational
phase, such water may be used to cover the tailings while they are accumulating.

Dust Management
Particular efforts are directed to dust control, since at the concentrations associated with
uranium (and some mineral sands) mining, dust is a potential health hazard. Dust rep-
resents the main potential exposure to alpha radiation as well as a gamma radiation haz-
ard. At any mine, employees likely to be exposed to radiation or radioactive materials are
regularly monitored for alpha radiation contamination and personal dosimeters are worn
to measure exposure to gamma radiation. Routine monitoring of air, dust and surface con-
tamination is undertaken.

Mine Closure
When closing down uranium mines, large amounts of radioactively contaminated equip-
ment and scrap are produced, which have to be disposed of in a safe manner. In most mine
operation the intention is to bury radioactively contaminated scrap on-site in mined-out
pits. However, no mine or mill site has yet been cleaned up in a permanently satisfactory
way anywhere in the world. Since it is impossible to avoid radioactive materials once they
are released from the deep rock and brought to the surface, the only remedy is 'long-term'
prevention of radioactive materials escaping into human environments.
The actual length of 'long-term' for prediction of environmental and radiological
impacts of abandoned uranium mines and tailings impoundments is not clearly dei ned.
The International Atomic Energy Agency considers long-term to be the period, beyond the
design life, for which climatological and geomorphological processes are more or less pre-
dictable and would not substantially affect the integrity of tailings impoundment systems.
This would be in the order of 1,000 to 10,000 years, practically forever in human terms.
Once uranium mines have been abandoned, it is doubtful whether any regulations can be
effective in preventing radioactive materials escaping into the environment over such long
periods of time. The levels of radioactivity in the tailings, and the amount of radon gas
produced by the tailings, will not noticeably diminish for more than 10,000 years. How can
the natural forces of erosion, migration, dispersion and dissolution be held in abeyance?
Who will monitor the wastes and take corrective action in, say two hundreds years from
now? And who will pay for the future effort needed to do all this ( Case 13.13 )?

The actual length of 'long-term'
for prediction of environmental
and radiological impacts of
abandoned uranium mines and
tailings impoundments is not
clearly defi ned.

CASE 13.13
The Wismut Legacy

Immediately after the end of World War II, the Soviets
started exploration and mining of uranium in the his-
toric mining provinces in the Ore Mountains, Germany.
Subsequently, the Wismut company developed the third-
largest uranium mining province of the world (after the
USA and Canada). With the political changes in 1989, it
came to light that uranium mining in Eastern Germany
had devastated large areas. Uranium production was ter-
minated but huge shut-down uranium mines, hundreds of
millions of tons of radiating waste rock and uranium mill

tailings remained. The environmental legacy does not only
present an immediate hazard, but also endangers future
generations for tens of thousands of years. The German
government estimates the clean-up to amount to more
than US$ 9 billion. If this estimate is attributed to the
amount of uranium produced, specifi c reclamation costs of
US$ 43 per kg of uranium produced are obtained which
compare to the current world market price for uranium of
about US$ 26/kg (as of December 2006).