Post by Catdaddy on Dec 20, 2007 17:48:04 GMT -5
Cigar Lake seal to be tested
Rabbit Lake mine could also restart production in February
Murray Lyons, The StarPhoenix
Published: Thursday, December 20, 2007
February could be a key month for Cameco Corp. as it tries to prove it can overcome mine flooding problems in northern Saskatchewan.
The uranium mining giant said Wednesday it should be ready to do an inflow test at its flooded Cigar Lake mine in about six weeks to determine whether efforts to seal a major water inflow area with concrete has succeeded.
"Essentially, we've sealed off the water flow," Cameco spokesperson Lyle Krahn said Wednesday following the release of the company's update on mine remediation work. The statement was issued after markets closed Wednesday. The inflow test is designed to prove the seal works, he said.
As well, in February Cameco should restart production underground at its Eagle Point mine at the Rabbit Lake facility, site of another water problem.
Cigar Lake, however, is the key asset that Cameco watchers and Cameco's partners in Cigar Lake, such as Areva Resources Canada, are observing. Cigar Lake, originally scheduled to open this year, was expected to become the second giant high-grade, underground uranium mine in the Athabasca basin, eventually matching the 18 million pounds of annual uranium output of Cameco's McArthur River mine. In June, delays at Cigar Lake helped to push the price of uranium for immediate delivery to a record $138 a pound.
In its most recent quarterly report issued in November, the company pushed back its expected production starting time at Cigar Lake to 2011. That start estimate didn't change with Wednesday's update, but Krahn said there is now more clarity, such as a prediction that the full mine dewatering might be completed in the second half of 2008.
For now, Cameco is cautiously optimistic it has been successful with work done from the surface during the past 14 months to pour concrete into the area where a rock fall occurred in October 2006, triggering the flood.
Earlier this fall, the company completed pouring a plug, using about 1,000 cubic metres of concrete. During the past two months, an additional 1,000 cubic metres of concrete was poured behind the plug and into the fractured area where the rock fall occurred.
The plan to test the plug's effectiveness involves drawing down some of the water in the production shaft and observing how quickly it fills back up. Krahn said the company already knows how much water comes in elsewhere in the mine so it can do calculations to be sure the grouting around the new concrete plug is letting only a manageable amount of water through.
"We'll be able to get a sense from what's coming in from around the area around the concrete plug," he said. "It's the rate of water flow back into the shaft and basically we're measuring that against the capacity we have to deal with the water."
Between now and February, grouting work around the plug will continue. The company also needs to backfill some of the holes that were drilled into the inflow area as part of the remediation work.
Cameco provided further explanation Wednesday on why a full dewatering of the mine will not occur until later next year, despite the February dewatering test. Cameco will be doing extensive geotechnical work on two other areas of the mine where the possibilities of water inflow problems are considered the most likely.
The company has already drilled five of six holes into these areas to check on water pressure, rock quality and structure and should have a report in hand by the first quarter of next year that will guide whether other reinforcement measures must be taken.
At Rabbit Lake, the company has completed the construction of four concrete bulkheads at two different levels underground to seal off an area of inflow that occurred in late November.
It will take until early February before the bulkheads have cured enough that they can be fully used. Already, however, Cameco reports it has the amount of water leaving the mine in balance with what is flowing in.
The company reports that as it suspected, the water inflow was caused by a decades-old exploration drill hole at Eagle Point that engineers also plan to seal with concrete.
Cameco will have produced four million pounds of uranium from the Eagle Point-Rabbit Lake mill complex this year and will issue a revised estimate on 2008 production in the coming weeks.
mlyons@sp.canwest.com
© The StarPhoenix (Saskatoon) 2007
Rabbit Lake mine could also restart production in February
Murray Lyons, The StarPhoenix
Published: Thursday, December 20, 2007
February could be a key month for Cameco Corp. as it tries to prove it can overcome mine flooding problems in northern Saskatchewan.
The uranium mining giant said Wednesday it should be ready to do an inflow test at its flooded Cigar Lake mine in about six weeks to determine whether efforts to seal a major water inflow area with concrete has succeeded.
"Essentially, we've sealed off the water flow," Cameco spokesperson Lyle Krahn said Wednesday following the release of the company's update on mine remediation work. The statement was issued after markets closed Wednesday. The inflow test is designed to prove the seal works, he said.
As well, in February Cameco should restart production underground at its Eagle Point mine at the Rabbit Lake facility, site of another water problem.
Cigar Lake, however, is the key asset that Cameco watchers and Cameco's partners in Cigar Lake, such as Areva Resources Canada, are observing. Cigar Lake, originally scheduled to open this year, was expected to become the second giant high-grade, underground uranium mine in the Athabasca basin, eventually matching the 18 million pounds of annual uranium output of Cameco's McArthur River mine. In June, delays at Cigar Lake helped to push the price of uranium for immediate delivery to a record $138 a pound.
In its most recent quarterly report issued in November, the company pushed back its expected production starting time at Cigar Lake to 2011. That start estimate didn't change with Wednesday's update, but Krahn said there is now more clarity, such as a prediction that the full mine dewatering might be completed in the second half of 2008.
For now, Cameco is cautiously optimistic it has been successful with work done from the surface during the past 14 months to pour concrete into the area where a rock fall occurred in October 2006, triggering the flood.
Earlier this fall, the company completed pouring a plug, using about 1,000 cubic metres of concrete. During the past two months, an additional 1,000 cubic metres of concrete was poured behind the plug and into the fractured area where the rock fall occurred.
The plan to test the plug's effectiveness involves drawing down some of the water in the production shaft and observing how quickly it fills back up. Krahn said the company already knows how much water comes in elsewhere in the mine so it can do calculations to be sure the grouting around the new concrete plug is letting only a manageable amount of water through.
"We'll be able to get a sense from what's coming in from around the area around the concrete plug," he said. "It's the rate of water flow back into the shaft and basically we're measuring that against the capacity we have to deal with the water."
Between now and February, grouting work around the plug will continue. The company also needs to backfill some of the holes that were drilled into the inflow area as part of the remediation work.
Cameco provided further explanation Wednesday on why a full dewatering of the mine will not occur until later next year, despite the February dewatering test. Cameco will be doing extensive geotechnical work on two other areas of the mine where the possibilities of water inflow problems are considered the most likely.
The company has already drilled five of six holes into these areas to check on water pressure, rock quality and structure and should have a report in hand by the first quarter of next year that will guide whether other reinforcement measures must be taken.
At Rabbit Lake, the company has completed the construction of four concrete bulkheads at two different levels underground to seal off an area of inflow that occurred in late November.
It will take until early February before the bulkheads have cured enough that they can be fully used. Already, however, Cameco reports it has the amount of water leaving the mine in balance with what is flowing in.
The company reports that as it suspected, the water inflow was caused by a decades-old exploration drill hole at Eagle Point that engineers also plan to seal with concrete.
Cameco will have produced four million pounds of uranium from the Eagle Point-Rabbit Lake mill complex this year and will issue a revised estimate on 2008 production in the coming weeks.
mlyons@sp.canwest.com
© The StarPhoenix (Saskatoon) 2007
