73
ment in which it is being undertaken. The purpose of the chapter is not to blame
anyone, but certainly it accounts the leading practices to inform the public debate on
uranium mining and to provide the framework approaches to the policymakers to
ensure the mining practices in a safe and environmentally responsible manner.
2 Uranium Characteristics, Reserves and Mining Process
Uranium is a naturally occurring silvery-grey element formed naturally in supernova
explosions, whereas +VI and +IV oxidation states are most stable in an aqueous
medium. The prime contributing natural terrestrial radioactive elements are uranium,
thorium and potassium. Moreover, there are different types of minerals, viz. uranite,
pitchblende, coffinite, brannerite, davidite, thucholite and thucholite, available in the
natural environment (Selvakumar et al. 2018) where
238
U (99.27%) and
235
U (0.72%)
are two natural available isotopes of uranium. Isotopes of uranium are radioactive
and fissionable, but only
235
U is fissile that support a neutron- mediated chain reaction. Generally, 2–4 μg g
−1
of uranium found in the earth’s crust and more concentrated amount of uranium is present in rock formation which can be mined (Wang
et al. 2016). The geological structure of worldwide uranium mine sites is given in
Table 3. Usually, there are three ways of uranium ore processing (as shown in Fig. 2),
but each one is creating health risks for local resident including the mine workers and
causing permanent damage to the environment as mentioned in the following.
2.1 Open-Pit (OP) Mining
The OP mining is used to remove near-surface deposits where the removal of rock
and soil is often required to access the uranium ore. This type of mining operation
generates ~40 tons of waste for each ton of the processed ore. Also, the seepage
from waste rock usually contains uranium in trace amount along with the heavy
metals and acids. The rainwater runoffs from OP mines necessitate the development
of large evaporation ponds (for storage) and expensive treatment facilities (for processing). The mining activities release dust and emit radon gas, which can end up in
waterways causing lung cancer if ingested.
2.2 Underground (UG) Mining
The UG mines are created using several shafts and tunnels in series. Miners must
need to go underground for building the machinery and access to the uranium ore.
During this activity, the workers get exposed to the high levels of radon. A large
quantity of water may proceed to exacerbate release of radon, while the soil subsidence and erosion can affect the neighbouring properties of the geological system.
Environmental and Health Impact Due to Uranium Mining
ment in which it is being undertaken. The purpose of the chapter is not to blame
anyone, but certainly it accounts the leading practices to inform the public debate on
uranium mining and to provide the framework approaches to the policymakers to
ensure the mining practices in a safe and environmentally responsible manner.
2 Uranium Characteristics, Reserves and Mining Process
Uranium is a naturally occurring silvery-grey element formed naturally in supernova
explosions, whereas +VI and +IV oxidation states are most stable in an aqueous
medium. The prime contributing natural terrestrial radioactive elements are uranium,
thorium and potassium. Moreover, there are different types of minerals, viz. uranite,
pitchblende, coffinite, brannerite, davidite, thucholite and thucholite, available in the
natural environment (Selvakumar et al. 2018) where
238
U (99.27%) and
235
U (0.72%)
are two natural available isotopes of uranium. Isotopes of uranium are radioactive
and fissionable, but only
235
U is fissile that support a neutron- mediated chain reaction. Generally, 2–4 μg g
−1
of uranium found in the earth’s crust and more concentrated amount of uranium is present in rock formation which can be mined (Wang
et al. 2016). The geological structure of worldwide uranium mine sites is given in
Table 3. Usually, there are three ways of uranium ore processing (as shown in Fig. 2),
but each one is creating health risks for local resident including the mine workers and
causing permanent damage to the environment as mentioned in the following.
2.1 Open-Pit (OP) Mining
The OP mining is used to remove near-surface deposits where the removal of rock
and soil is often required to access the uranium ore. This type of mining operation
generates ~40 tons of waste for each ton of the processed ore. Also, the seepage
from waste rock usually contains uranium in trace amount along with the heavy
metals and acids. The rainwater runoffs from OP mines necessitate the development
of large evaporation ponds (for storage) and expensive treatment facilities (for processing). The mining activities release dust and emit radon gas, which can end up in
waterways causing lung cancer if ingested.
2.2 Underground (UG) Mining
The UG mines are created using several shafts and tunnels in series. Miners must
need to go underground for building the machinery and access to the uranium ore.
During this activity, the workers get exposed to the high levels of radon. A large
quantity of water may proceed to exacerbate release of radon, while the soil subsidence and erosion can affect the neighbouring properties of the geological system.
Environmental and Health Impact Due to Uranium Mining