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Cigar Lake

North America map showing location of Cigar Lake development project

Cigar Lake is the world’s second largest high-grade uranium deposit, with grades that are 100 times the world average. We are a 50% owner and the mine operator.

Cigar Lake, which is being developed and scheduled to begin production this year, is one of our three material uranium properties.

Location Saskatchewan, Canada
Ownership 50.025%
End product Uranium concentrates
Mine type Underground
Estimated reserves (our share) 108.4 million pounds (proven and probable), average grade U3O8: 18.30%
Estimated resources (our share) 1.1 million pounds (measured and indicated), average grade U3O8: 2.27%
49.5 million pounds (inferred), average grade U3O8: 12.01%
Mining methods Jet boring
Target production date First mine production in the first quarter of 2014
Begin processing ore at the McClean Lake mill by the end of the second quarter of 2014
Target annual production (our share) 9.0 million pounds at full production (18.0 million pounds on 100% basis)
2014 forecast production (our share) 1.0 – 1.5 million pounds (2.0 to 3.0 million pounds on 100% basis)
Estimated decommissioning cost (100% basis) $49 million

Diagram of Cigar Lake underground mine



We began developing the Cigar Lake underground mine in 2005, but development was delayed due to water inflows (two in 2006 and one in 2008). The first inflow flooded shaft 2 while it was under construction. The second inflow flooded the underground development and we began remediation late in 2006. In 2008, another inflow interrupted the dewatering of the underground development. We sealed the inflows and completed dewatering of shafts 1 and 2. In 2011, we completed remediation of the underground.

Mining method

We will use a number of innovative methods and techniques to mine the Cigar Lake deposit:

Bulk freezing

The sandstone that overlays the deposit and basement rocks is water-bearing, with large volumes of water under significant pressure. We will freeze the ore zone and surrounding ground in the area to be mined to prevent water from entering the mine and to help stabilize weak rock formations.

Our plan is to use a hybrid freezing approach. We will use surface freezing to support the rampup period and underground freezing for the longer term development of the mine. Through 2013, we continued to drill freezeholes from surface, expand the surface freezing infrastructure and put the new freezeholes in operation. To manage our risks and meet our production schedule, the area being mined must meet specific ground freezing requirements before we begin jet boring.

Jet boring

After many years of test mining, we selected jet boring, a non-entry mining method, which we have developed and adapted specifically for this deposit. Overall, our initial test program was a success and met all initial objectives. This method involves:

  • drilling a pilot hole into the frozen orebody, inserting a high pressure water jet and cutting a cavity out of the frozen ore
  • collecting the ore and water mixture (slurry) from the cavity and pumping it to storage (sump storage), allowing it to settle
  • using a clamshell, transporting the ore from the sump storage to a grinding and processing circuit, eventually loading a tanker truck with ore slurry for transport to the mill
  • once mining is complete, filling each cavity in the orebody with concrete
  • starting the process again with the next cavity

Jet boring system process

Diagram illustrating jet boring system process

We have divided the orebody into production panels, and will have one jet boring mining unit operating in a panel. At least four production panels need to be frozen at one time to achieve the full production rate of 18 million pounds per year. At full production, two jet boring machines will be working at a time, while the other two are being moved, set up, in the backfill cycle or on maintenance.

In September 2013, we announced that we had identified additional underground work that would delay jet boring in ore. After the work was completed, we jetted the first ore cavity in December 2013, and expect to begin ore production from the mine during the first quarter of 2014.


All of Cigar Lake’s ore slurry will be processed at the McClean Lake mill, operated by AREVA. The McClean Lake mill requires modification and expansion to process and package all of Cigar Lake’s current mineral reserves. The Cigar Lake joint venture has agreed to pay for the capital costs for such modification and expansion.

In September 2013, AREVA advised us that it had determined that further mill modifications were required before they could begin processing Cigar Lake ore. The McClean Lake mill is expected to begin processing Cigar Lake ore by the end of the second quarter of 2014.

2013 update

During the year, we:

  • completed construction and began commissioning of all infrastructure required to begin ore production
  • successfully tested the jet boring system in waste and began commissioning in ore
  • continued freezing the ground from surface to ensure frozen ore is available for future production years


As of December 31, 2013, we had:

  • invested about $1.1 billion for our share of the construction costs to develop Cigar Lake
  • expensed about $86 million in remediation expenses
  • expensed about $100 million in standby costs
  • expensed about $102 million to begin commissioning

In August 2013, we announced that our share of the total capital cost for Cigar Lake was expected to increase between 15% and 25% as a result of scope changes, increased costs at the mine and mill, and the inclusion of some capital costs that will be incurred subsequent to the mining of the first ore that were not included in our previous estimate. Our total share of the capital cost for this project is now estimated to be about $1.3 billion (previously $1.1 billion) since we began development in 2005. In order to bring Cigar Lake into production in 2014, we estimate our share of capital expenditures will be about $130 million, including $100 million on modifications to the McClean Lake mill. Additional expenditures of about $35 million will be required at McClean Lake mill in 2015 in order to continue ramping up to full production. Our share of standby charges until production is achieved this year is estimated to be about $15 million.


The CNSC granted a uranium mining licence authorizing construction and operation of the Cigar Lake project. The licence term is from July 1, 2013 to June 30, 2021.

Planning for the future


In 2014, we expect:

  • to bring the mine into production in the first quarter of 2014
  • processing of the ore to begin at AREVA’s McClean Lake mill by the end of the second quarter of 2014

Rampup schedule

We expect Cigar Lake to produce between 2 million and 3 million packaged pounds from the mill (100% basis) in 2014. Based upon our commissioning and rampup experience, we will adjust our plans as necessary to allow us to reach our full production rate of 18 million pounds (100% basis) by 2018.

Given the scale of this project and the challenging nature of the geology and mining method, we have made significant progress. We will continue to develop this asset in a safe and deliberate manner to ensure we realize the economic benefits of this project.

Caution regarding forward-looking information

Our expectations and plans regarding Cigar Lake, including our expected share of 2014 production, achievement of the full production rate of 18 million pounds by 2018, and capital costs, are forward-looking information. They are based on the assumptions and subject to the material risks discussed here, and specifically on these assumptions and risks:


  • our Cigar Lake development, mining and production plans succeed
  • there is no material delay or disruption in our plans as a result of ground movements, cave-ins, additional water inflows, a failure of seals or plugs used for previous water inflows, natural phenomena, delay in acquiring critical equipment, equipment failure or other causes
  • there are no labour disputes or shortages
  • our bulk ground freezing program progresses fast enough to deliver sufficient frozen ore to meet production targets
  • our expectation that the jet boring mining method will be successful and that we will be able to solve technical challenges as they arise in a timely manner
  • our expectation that we will be able to obtain the additional jet boring system unit we require on schedule
  • we obtain contractors, equipment, operating parts, supplies, regulatory permits and approvals when we need them
  • mill modifications and commissioning of the McClean Lake mill are completed as planned and the mill is able to process Cigar Lake ore as expected, AREVA will be able to solve technical challenges as they arise in a timely manner, and sufficient tailings facility capacity is available
  • our mineral reserves estimate and the assumptions it is based on are reliable

Material risks

  • an unexpected geological, hydrological or underground condition or an additional water inflow, further delays our progress
  • ground movements or cave-ins
  • we cannot obtain or maintain the necessary regulatory permits or approvals
  • natural phenomena, labour disputes, equipment failure, delay in obtaining the required contractors, equipment, operating parts and supplies or other reasons cause a material delay or disruption in our plans
  • sufficient tailings facility capacity is not available
  • our mineral reserves estimate is not reliable
  • our development, mining or production plans for Cigar Lake are delayed or do not succeed for any reason, including technical difficulties with the jet boring mining method or freezing the deposit to meet production targets, technical difficulties with the McClean Lake mill modifications or commissioning or milling Cigar Lake ore, or our inability to acquire any of the required jet boring equipment

Managing our risks

Cigar Lake is a challenging deposit to develop and mine. These challenges include control of groundwater, weak rock formations, radiation protection, water inflow, mining method uncertainty, regulatory approvals, tailings capacity, surface and underground fires and other mining-related challenges. To reduce this risk, we are applying our operational experience and the lessons we have learned about water inflows at McArthur River and Cigar Lake.

Mill modifications

There is a risk to Cigar Lake’s rampup schedule if the McClean Lake mill does not begin processing ore from the Cigar Lake mine by the end of the second quarter, 2014. There is also a risk to our plan to achieve the full production rate of 18 million pounds per year by 2018 if AREVA is unable to complete and commission the required mill upgrades on schedule. We are working closely with AREVA to understand and help mitigate the risks to ensure that mine and mill production schedules are aligned.

Ground freezing

To manage our risks and meet our production schedule, the areas being mined must meet specific ground freezing requirements before we begin jet boring. We have identified greater variation of the freeze rates of different geological formations encountered in the mine, based on new information obtained through surface freeze drilling. As a mitigation measure, we have increased the site freeze capacity to facilitate the extraction of ore cavities as planned.

Jet boring mining method and units

Although we have successfully tested the jet boring mining method in waste rock and began commissioning the system in ore, this method has not been proven at full production. As we ramp up production, there may be some technical challenges that could affect our production plans, including, but not limited to, variable or unanticipated ground conditions, ground movement and cave-ins, water inflows and variable dilution, recovery values and mining productivity. There is a risk that the rampup to full production may take longer than planned and that the full production rate may not be achieved on a sustained and consistent basis. A comprehensive commissioning and startup plan is underway with the objective to assure successful startup and on-going operations. We are confident we will be able to solve challenges that may arise, but failure to do so would have a significant impact on our business.

Our mining plan requires four jet boring system units. We currently have two units on site and a third unit has been ordered and manufactured. We have an agreement with a supplier to supply one additional jet boring system unit. There is a risk that rampup to full production at Cigar Lake may take longer than planned if the manufacture or delivery of the fourth unit does not take place as scheduled. As part of our startup plan, we are working with our supplier to assure timely delivery of the fourth unit.

Water inflow risk

A significant risk to development and production is from water inflows. The 2006 and 2008 water inflows were significant setbacks.

The consequences of another water inflow at Cigar Lake would depend on its magnitude, location and timing, but could include a significant delay in Cigar Lake’s development or production, a material increase in costs or a loss of mineral reserves.

We take the following steps to reduce the risk of inflows, but there is no guarantee that these will be successful:

  • Bulk freezing: Two of the primary challenges in mining the deposit are control of groundwater and ground support. Bulk freezing reduces but does not eliminate the risk of water inflows.
  • Mine development: We plan for our mine development to take place away from known groundwater sources whenever possible. In addition, we assess all planned mine development for relative risk and apply extensive additional technical and operating controls for all higher risk development.
  • Pumping capacity and treatment limits: We have pumping capacity to meet our standard for this project of at least one and a half times the estimated maximum inflow.

We believe we have sufficient pumping, water treatment and surface storage capacity to handle the estimated maximum inflow.

We also manage the risks listed here.