Rayrock Mine
Encyclopedia
The Rayrock Mine was a uranium
producing venture in the Northwest Territories
, Canada
. It is located on the south side of Maryleer Lake and the north shore of Fault Lake, 169 kilometers northwest of Yellowknife and 74 kilometres northwest of Rae
. Radioactive deposits were originally staked in 1948 and then restaked in 1950. American Yellowknife Mines Limited explored the site with detailed Geiger surveys and extensive trenching in the early 1950s. In 1954 exploration work included over 10000 feet (3,048 m) of surface diamond drilling, and the company was reorganized as Rayrock Mines Limited.
Underground development began in 1955 with the driving of a long adit tunnel to intersect the radioactive zones 300 feet (91.4 m) below surface. The mine opened in June 1957 with a 150 tons per day leaching mill. Development was expanded and the mine reached depths of 1000 feet (304.8 m) by the end of 1957. The failure to locate ore in significant quantity below the 1000 feet (304.8 m) level resulted in the cessation of mining on July 31, 1959.
During the operations at Rayrock Mine, an on-site mill facility processed 78,781 short tons of uranium ore yielding 458,020 pounds of uranium concentrate. Rayrock Mine was a fully underground uranium mine with a small townsite built by the company being in operation during this period. The mine employed 135 men in 1958 and the townsite had 20 families as residents. The mining facility and town existed in an abandoned state for over twenty years after the mine closed.
In 1987, the buildings of the mine and town were demolished. Environmental clean up began in 1996, with the objective being to contain contaminants at the site and limit exposure to persons who visit the area. Remediation activities included sealing mine openings, removing radioactive material from the dump, disposing of this contaminated material on the tailings, and capping the tailings piles with a layer of silty clay, followed by revegetation.
The territorial government has agreed to long-term monitoring of the site in order to ensure radiation levels and contamination does not threaten the area. This is to be conducted annually until 2009. After this time followed by once every 10 years for a further 100 years. This may change if results warrant adjustment, such as some minor care and maintenance work completed in summer 2004. Monitoring assesses the integrity of sealed mine openings, water quality and potential risks to humans.
Uranium
Uranium is a silvery-white metallic chemical element in the actinide series of the periodic table, with atomic number 92. It is assigned the chemical symbol U. A uranium atom has 92 protons and 92 electrons, of which 6 are valence electrons...
producing venture in the Northwest Territories
Northwest Territories
The Northwest Territories is a federal territory of Canada.Located in northern Canada, the territory borders Canada's two other territories, Yukon to the west and Nunavut to the east, and three provinces: British Columbia to the southwest, and Alberta and Saskatchewan to the south...
, Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
. It is located on the south side of Maryleer Lake and the north shore of Fault Lake, 169 kilometers northwest of Yellowknife and 74 kilometres northwest of Rae
Behchoko, Northwest Territories
Behchokǫ̀ , officially the Tłı̨chǫ Community Government of Behchokǫ̀ is a community in the North Slave Region of the Northwest Territories, Canada. Behchokǫ̀ is located on the Yellowknife Highway , on the northwest tip of Great Slave Lake, approximately northwest of Yellowknife...
. Radioactive deposits were originally staked in 1948 and then restaked in 1950. American Yellowknife Mines Limited explored the site with detailed Geiger surveys and extensive trenching in the early 1950s. In 1954 exploration work included over 10000 feet (3,048 m) of surface diamond drilling, and the company was reorganized as Rayrock Mines Limited.
Underground development began in 1955 with the driving of a long adit tunnel to intersect the radioactive zones 300 feet (91.4 m) below surface. The mine opened in June 1957 with a 150 tons per day leaching mill. Development was expanded and the mine reached depths of 1000 feet (304.8 m) by the end of 1957. The failure to locate ore in significant quantity below the 1000 feet (304.8 m) level resulted in the cessation of mining on July 31, 1959.
During the operations at Rayrock Mine, an on-site mill facility processed 78,781 short tons of uranium ore yielding 458,020 pounds of uranium concentrate. Rayrock Mine was a fully underground uranium mine with a small townsite built by the company being in operation during this period. The mine employed 135 men in 1958 and the townsite had 20 families as residents. The mining facility and town existed in an abandoned state for over twenty years after the mine closed.
In 1987, the buildings of the mine and town were demolished. Environmental clean up began in 1996, with the objective being to contain contaminants at the site and limit exposure to persons who visit the area. Remediation activities included sealing mine openings, removing radioactive material from the dump, disposing of this contaminated material on the tailings, and capping the tailings piles with a layer of silty clay, followed by revegetation.
Contamination
The site became contaminated with radioactive tailings that were deposited on land. Some of these dangerous tailing flowed into three small lakes. When the mine closed tailings basins contained 70,903 tonnes of radioactive tailings that had the potential to leach metals. The mine shafts itself also create a source of potential radioactive contamination through radon gas emissions from the mine openings.The territorial government has agreed to long-term monitoring of the site in order to ensure radiation levels and contamination does not threaten the area. This is to be conducted annually until 2009. After this time followed by once every 10 years for a further 100 years. This may change if results warrant adjustment, such as some minor care and maintenance work completed in summer 2004. Monitoring assesses the integrity of sealed mine openings, water quality and potential risks to humans.