Uranium Mining in Northern Saskatchewan

The Athabasca Basin of northern Saskatchewan has been the site of all major Canadian uranium discoveries in the past 40 years. The first northern Saskatchewan uranium deposits were discovered in the early 1950s and Eldorado began mining at Beaverlodge Mine in 1953.

In 1968, the Rabbit Lake deposit was discovered in northern Saskatchewan by Gulf Minerals Ltd. and the German-owned Uranerz Exploration and Mining Limited, and by 1975 the mine and mill were in operation. Rabbit Lake was subsequently sold to Eldorado Nuclear (now Cameco Corporation) in 1981. The deposits at Rabbit Lake include the mined-out original Rabbit Lake open pit, the mined out Collins Bay open pits, as well as the currently operating Eagle Point underground mine.

Rabbit Lake
Rabbit Lake is the longest uranium mine in operation in Saskatchewan.

In 1975, the French-owned company Amok Ltd. (later to become Cogema Resouces Inc, and now the French company AREVA, the largest nuclear company in the world) discovered the Cluff Lake deposit, which operated from 1980 until 2002. 1975 also marked the discovery of the large Key Lake deposit by Uranerz Canada Ltd. A 50% interest in this deposit was sold to Saskatchewan Mining Development Corporation, a provincial Crown corporation. Production began in 1983, and Key Lake became the highest grade and largest uranium mine in the world at the time. Although mining ceased in 1997, there continues to be some production attributed to Key Lake as special waste rock from the mine is currently blended with ore from the McArthur River mine and processed in the mill.

Mining in the 1980s and 1990s was primarily by the open-pit method as the deposits were near the surface. Surface mining is more economical than underground mining and, combined with the very high ore grade found in the Athabasca Basin, made this uranium very competitive in world markets. The high ore grade also requires that great care be taken to ensure radiation protection for workers.

Rabbit Lake - scoop
Remote control scoop tram at the Rabbit Lake mine.

In 1988, the federal and Saskatchewan governments agreed to the amalgamation of their respective crown corporations, Eldorado Nuclear Limited and Saskatchewan Mining Development Corporation. The resulting company, Cameco Corporation, is currently the world’s largest uranium producer, having purchased most of Uranerz’s Canadian holdings. In 1987, Cogema Resources Inc., a French government-owned company, purchased all of Amok’s Canadian interests as well as some of the Uranerz holdings. In 2006 Cogema was renamed AREVA Resources Canada Inc. AREVA is the other major player in Saskatchewan uranium mining and also produces uranium in other countries, ranking third in total uranium production.

The Cigar Lake deposit was discovered in 1981 and construction started in the summer of 1997. The Cigar Lake ore body is the richest undeveloped uranium deposit in the world, with an average ore grade of 18% U3O8 (uranium oxide). It is also one of the largest, with geological reserves totaling 103,000 tonnes of U3O8. It will be mined from tunnels above and below the ore zone, using a water-jet boring technique on ore after is has been frozen. The ore will be crushed, ground, mixed with water, and then pumped as slurry to the surface for transportation to the mill. Special remote-control mining methods will be necessary due to the high radiation fields. However, the Cigar Lake mine flooded during construction in October 2006 due to a rock fall with pumping out the water starting in mid 2008. Production is now scheduled to start by 2011.

Cigar Lake
Underground tunnels at the Cigar Lake mine are reinforced with concrete to ensure a safe working environment.

In 1988, the massive, high-grade McArthur River ore body was discovered. With geological reserves totalling 158,000 tonnes of U3O8 at an average grade of close to 20% U3O8, this is the largest known high-grade uranium deposit in the world. The McArthur River mine commenced production in July 1999 and is operated by Cameco Corporation. At a depth of 550 metres, it is mined by underground methods similar to those to be used at Cigar Lake. The ore is processed at the Key Lake mill and the mill tailings, or wastes, are placed into the former Deilmann pit of the Key Lake mine, which has been converted into a tailings management facility. The facility uses the “pervious surround” method, which has been successfully used at the Rabbit Lake mill since 1985. Mining at McArthur River produced 8,500 tonnes of U3O8 in 2007.

McArthur River Mine

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As noted Canada’s uranium production in 2009 was 10,123 tonnes U3O8, which represented about 20% of world output. About 75% of this production came from the McArthur River mine alone. Canada’s identified uranium resources are about 8% of the world total with Australia’s identified uranium resources about three times as large.

McArthur River
Located in northern Saskatchewan, the McArthur River mine has an annual uranium production capacity of 18.7 million pounds of U3O8.

With their enormous reserves and exceptionally high uranium concentrations, about 100 times the world average grade, the Cigar Lake and McArthur River mines are the future of Saskatchewan uranium mining and eclipse any other deposits in the world.

Saskatchewan Uranium Mines
Deposit
Mining Method
Owner
Tonnes U3O8
Average Grade
Cigar Lake
Underground
Cameco
216,700
18.3%
Key Lake
Open-pit
Cameco
700
0.5%
McArthur
Underground
Cameco, AREVA
378,900
16.9%
McClean Lake
Open-pit, underground
AREVA
16,200
2.2%
Midwest
Open-pit
Cameco
5,800
1.7%
Rabbit Lake
Underground
Cameco
22,800
1.7%

The enormous bounty of uranium buried in the Athabasca Basin is almost beyond reckoning and can provide substantial wealth to the province of Saskatchewan and Canada for decades to come. It is estimated that the energy contained in these deposits is equivalent to 17 billion barrels of oil or at a typical 2008 oil price of $130 per barrel about $2.2 trillion.