Environment & Safety
Radiation tests are ongoing in the bulk neutralization area of the Key Lake mill.
Worker Safety
- Radiation doses for all workers at Key Lake are well below allowable limits.
- Workers' cumulative gamma doses are recorded on radiation badges.
Results are reported to the regulators and to Cameco employees.
- Cameco also conducts an annual sampling program related to worker
safety involving thousands of samples. The results of the sampling
show that the workplaces are safe.
Tailings Management
Tailings are placed in an engineered tailings management facility built into the mined-out Deilmann pit.
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The purpose of tailings management is to isolate and store the
waste residue from the milling process so that people and the environment
are protected. This involves containing the
solids and treating the water to quality standards acceptable for
release to the environment. The waste metals removed from the water
are disposed of as solids in the tailings management facility.
From 1983 to 1996, waste from the Key Lake mill was deposited in
a surface tailings management facility 600 metres by 600 metres
and 15 metres deep.
The mined-out Deilmann open pit is now used as a tailings facility.
The tailings facility was constructed five metres above the groundwater
table and used a modified bentonite liner as a seal to line the
bottom and isolate the tailings from the surrounding soil infrastructure.
The mined-out Deilmann open pit is now used as a tailings facility.
It was commissioned in January 1996 to store the remainder of
Key Lake tailings and McArthur River tailings.
This tailings facility is constructed in the basement rock of the
mined-out pit.
Tailings are placed in a highly permeable envelope
of crushed rock and sand in the mined-out pit. Residual water on
the surface and the tailings is removed during tailings placement
and collected for treatment. The consolidated tailings become a
low-permeability mass contained in a permeable envelope. After decommissioning,
groundwater will take the path of least resistance, around the tailings,
rather than through them. Environmental impacts will be minimal.
Decommissioning
Areas no longer in use at Key Lake are being landscaped and revegetated to return them as much as possible to their predevelopment state.
Cameco is committed to environmentally safe operations and is continually
monitoring to ensure the environment is
protected. Areas no longer in use are landscaped and revegetated
to return them as much as possible to their predevelopment state.
When the Deilmann tailings management facility is ready to be decommissioned,
it will be covered with clean material and groundwater
will be allowed to rise to natural levels.
Safety, Health, Environment and Quality Policy
