Cigar Lake work on track, delayed or postponed? Cigar Lake to be abandoned? What is the truth in all these swirling rumours concerning Cameco’s flagship uranium mine? 

Whatever it is, we won’t hear it any time soon—and that observation presumes that there is a “truth.” I suspect that everybody involved in the now-flooded workings is scrambling too hard to fix things to debate a Platonic “truth,” which leaves the investor not simply guessing but, in practice, gambling. 

Let us have a look at the technicalities to see if we can probe deeper than news releases and stock speculations. (And look at a more recent article on this blog.)

The only reasonable technical paper I could locate anywhere on the web is by Barry W Schmitke. It is called Cigar Lake’s Jet Boring Mining Method and was presented in 2004 to the World Nuclear Association Annual Symposium. To access the figures go to this link. 

Here are some extracts: 

• The Cigar Lake orebody is situated 430 metres below surface at the nonconformity between metamorphic basement rocks and flat lying sandstone. Major technical factors influencing the mining method selection include ground stability, control of ground water (sic), radiation exposure and ore handling and storage. 
• Cigar Lake’s jet boring mining method involves several major steps: artificial ground freezing of the orebody and surrounding rock; TBM (tunnel boring) type development of access crosscuts below the orebody; installation of cased pilot holes upwards through the ore; and ore extraction using a rotating high pressure water jet within the pilot holes.
• The cap [i.e., the clay above the orebody] is succeeded upwards by a highly heterogeneous, highly permeable zone from 20 m to 50 m thick consisting of variable soft to moderately indurated sandy clay, unconsolidated sand, and variably altered sandstone. 
• The deposit and area are highly fractured. Post-mineralization fracturing is the dominant control of hydraulic conductivity and, where it transects the otherwise impervious claystone core of the deposit, fracturing acts as conduits for water, sand, and soft clay. 
• Two of the primary geotechnical challenges in constructing the test mine have been control of groundwater, and ground support in areas of weak rock. 
• The support of the weak rock associated with the oreboby and the minimization of the potential for a large inrush of water while mining the ore was addressed through ground freezing. 

The paper proceeds to describe a test mine program and concludes: “The overall test mine program and, in particular, the 2000 Industrial Jet Boring Test, were considered highly successful with all initial objective fulfilled and results meeting expectations.”

In October 2006, we read many reports that all amounted to the same thing: 

Cameco engineers and consultants are on site working on plans to restore underground access to the Cigar Lake project in response to a major flooding incident on Monday. International experts are assisting with reviewing options and developing a remediation plan. We anticipate that a phased plan will be in place within three months outlining a preferred option and several alternatives. Most of the alternatives under consideration involve drilling from the surface and isolating the source of the inflow from the underground workings by using grouting or freezing techniques and then pumping the water out of the mine.

The most recent news release, February 7, 2007 says:

Cameco Corp. reported a sharp drop in fourth-quarter profits due to problems at the project at its Cigar Lake project and said Wednesday preliminary cost estimates will take longer than initially expected… The company took a Can$15 million write down related to Cigar Lake, which was flooded last April and again in October, as well as another $5 million in costs related to remediation activities at the project in the fourth quarter.  Cameco said Wednesday two drill rigs on site working around the clock have drilled eight of the 14 drill holes planned for reinforcing and sealing off the flooded area. The company had hoped to provide preliminary cost estimates and timelines for the remediation in February, but said Wednesday a technical report on the project will not be finished until late March, when it hopes to have a better idea of when the mine will be able to be put into production.

I do not know which consultants or which companies are involved in the ongoing work at the mine. The following are simply extracts from documents you could find on the web as easily as I did:

1. Controlled ground freezing for mining and construction applications has been in use for over a century. Despite the great technological evolution which has occurred during this period, it still remains more of an art than a science. (Link) 
2. The present ground freezing technology used worldwide by most ground freezing companies is based on quick freezing using circulating brine or, in some cases, liquid nitrogen. These methods are fast but very expensive and utilize large equipment with high electrical requirements. (Link)
3. In any ground freezing scenario, the presence of flowing water can significantly delay or even prevent the development of ice due to heat addition by the moving water.  (Link)
4. The uncertainty of the pre-evaluation of potential ground water inflow rates in underground mines results in difficulty in planning and costing the water-related activities of the mines.  (Link)
5. Water in-rushes sometimes cause stoppages to shaft sinking operations because the sidewalls must be sealed or stabilized. Pre-grouting can to a large extent preclude in-rushes.  (Link)

I am sure we could find thousands more—see  this link for some of them. The simple fact is that at the Cigar Lake mine there are highly permeable soils and rocks above the ore body. There is no way anybody can absolutely characterize the water flow pattern. It is inherently uncharacteristic. This does not mean the ore cannot be mined. People have applied the art of engineering for a long time to deal with conditions like those at the mine. For over 100 years the mines of the South African Witwatersrand have collectively pumped the groundwater out and lowered the  regional water table. I grew up on stories of one mine flooding when the adjacent mine stopped pumping. 

The difference here is that we have but one isolated Canadian mine pumping all alone in the glare of the investment community’s spotlight.  The key issue that is utterly unquantifiable is how much it will cost to do what can obviously be done. If it costs lots, they will succeed. If it cost more, share prices will tumble, but the mine will go into production. And if it cost too much, they will shut it down and leave the uranium to nature, and the shareholders will cry. If you are one of them, stop frittering away hours trying to get leads on the internet. Face the fact that this is a gamble: you do not know what will happen and nobody can tell you what will happen. Go to Las Vegas and relax. I will be there in April so let us meet and compare notes. And let us wish the engineers, groundwater hydrologists, and miners the best success.

We all want them to succeed for our own very different reasons.   See a newer (2 March 2007) opinion for more news & views.