Cigar Lake uranium deposit (English labels)

The Cigar Lake Mine is a large high-grade underground

uranium Uranium is a chemical element with the symbol U and atomic number 92. It is a silvery-grey metal in the actinide series of the periodic table. A uranium atom has 92 protons and 92 electrons, of which 6 are valence electrons. Uranium is weak ...

mine, located in the uranium-rich

Athabasca Basin The Athabasca Basin is a region in the Canadian Shield of northern Saskatchewan and Alberta, Canada. It is best known as the world's leading source of high-grade uranium and currently supplies about 20% of the world's uranium. The basin i ...

of northern

Saskatchewan Saskatchewan ( ; ) is a province in western Canada, bordered on the west by Alberta, on the north by the Northwest Territories, on the east by Manitoba, to the northeast by Nunavut, and on the south by the U.S. states of Montana and North Dak ...

, Canada, at the south-west corner of Waterbury Lake. The deposit, discovered in 1981, is second in size of high-grade deposits only to the nearby McArthur River mine. Other deposits, such as Olympic Dam in Australia, contain more uranium but at lower grades.

History

Full-scale construction began in 2005 with production originally planned for 2007, but the mine experienced a catastrophic water inflow in October 2006, which flooded the mine. A second inflow occurred in 2008 during the first attempt at dewatering the mine after sealing the initial inflow. Remediation efforts continued, and re-entry was successfully accomplished in 2010. Production was delayed several times with the startup dates being announced for 2011, 2013, and 2014. On March 13, 2014, ore production began at the mine, with the mining system and underground processing circuits operational and

uranium ore Uranium ore deposits are economically recoverable concentrations of uranium within the Earth's crust. Uranium is one of the more common elements in the Earth's crust, being 40 times more common than silver and 500 times more common than gold. It ...

transported to the McClean Lake mill operated by AREVA Resources Canada Inc. located northeast of the minesite. The deposit is located at depth of , surrounded by and isolated within a layer of water-impermeable

illite Illite is a group of closely related non-expanding clay minerals. Illite is a secondary mineral precipitate, and an example of a phyllosilicate, or layered alumino-silicate. Its structure is a 2:1 sandwich of silica tetrahedron (T) – alumina ...

- chlorite clay, within the Athabasca Sandstone formation. Its age is estimated to be 1.3 billion years. Due to natural containment and lack of any traces of radioactive elements on the surface, the deposit is used as an example of an effective natural

deep geological repository A deep geological repository is a way of storing hazardous or radioactive waste within a stable geologic environment (typically 200–1000 m deep). It entails a combination of waste form, waste package, engineered seals and geology that is suite ...

. During 2020, production was temporarily suspended over two periods due to the risks posed by the

COVID-19 pandemic The COVID-19 pandemic, also known as the coronavirus pandemic, is an ongoing global pandemic of coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The novel virus was first identi ...

: from March until September; and then from 14 December 2020. Production at

Orano Orano SA is a multinational nuclear fuel cycle company headquartered in Châtillon, Hauts-de-Seine, France. The company is engaged in uranium mining, conversion-enrichment, spent fuel recycling, nuclear logistics, dismantling, and nuclear cy ...

's McClean Lake uranium mill, which processes the ore from the Cigar Lake mine, was also suspended. The

Canadian Nuclear Safety Commission The Canadian Nuclear Safety Commission (CNSC; french: Commission Canadienne de sûreté nucléaire) is the federal regulator of nuclear power and materials in Canada. Mandate and history Canadian Nuclear Safety Commission was established under t ...

took regulatory action again owners Cameco Corporation in October 2022 due to the volume of waste material placed on waste pile C.

Reserves and resources

As of 31 December 2020, Cigar Lake had proven and probable reserves of of

triuranium octoxide Triuranium octoxide (U3O8) is a compound of uranium. It is present as an olive green to black, odorless solid. It is one of the more popular forms of yellowcake and is shipped between mills and refineries in this form. U3O8 has potential long-ter ...

() at an average grade of 15.92%, for 75,070 tonnes of , and a measured and indicated resource of of at an average grade of 13.88%, for 47,514 tonnes of .

Ownership

The mine is owned by

Cameco Corporation Cameco Corporation (formerly Canadian Mining and Energy Corporation) is the world's largest publicly traded uranium company, based in Saskatoon, Saskatchewan, Canada. In 2015, it was the world's second largest uranium producer, accounting for 18 ...

(50.025%), AREVA Resources Canada Inc (37.1%), Idemitsu Canada Resources Ltd. (7.875%), and

TEPCO , also known as or TEPCO, is a Japanese electric utility holding company servicing Japan's Kantō region, Yamanashi Prefecture, and the eastern portion of Shizuoka Prefecture. This area includes Tokyo. Its headquarters are located in Uchi ...

Resources Inc. (5%). Cameco is the project operator.

Wolf attacks

In 2005, a worker was killed by wolves at

Points North Landing Points North Landing is a camp settlement in northeastern Saskatchewan, Canada. It is 355 kilometres north-east of La Ronge, on Highway 905 and has an airport and a water aerodrome, with almost daily flights provided by West Wind Aviation and ...

, near Cameco's

Rabbit Lake mine Rabbit Lake is the second largest uranium milling facility in the western world, and is the longest operating uranium production facility in Saskatchewan. The facility is located approximately 800 km north of Saskatoon, Saskatchewan, on the n ...

. On August 29, 2016, a 26-year-old shift worker walking between buildings at the Cigar Lake mine on his midnight break was attacked and mauled by a lone timber wolf. A nearby security guard frightened the wolf away, administered first aid, and called for an air ambulance which airlifted him to a hospital in

Saskatoon Saskatoon () is the largest city in the Canadian province of Saskatchewan. It straddles a bend in the South Saskatchewan River in the central region of the province. It is located along the Trans-Canada Yellowhead Highway, and has served as th ...

where he recovered. After the attack, authorities ordered that area wolves be shot, that food disposal systems and fencing be inspected, and that staff be educated.Wolf expert says human habituation likely reason for Cigar Lake attack
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References

External links