america: the next uranium giant, page-47

i do have some other interesting figures that you might be interested in though. ( still looking)

STOCKINTERVIEW: What will be the key to a successful U.S. ISR operation?
DAVID MILLER: The key to ISR will be permeability, grade, thickness, and depth – pretty much in that order. With low or no permeability the deposit will need to be conventionally mined. A high permeability, low or medium grade deposit at less than 1000 feet will be a very attractive operation. After you have a certain volume of uranium to justify the capital costs of an operation, I would rather have good permeability and low grade than low permeability and high grade, if I am going to use ISR as my recovery technique. Of course with conventional mining I will take the highest grades we can get.

STOCKINTERVIEW: How large would a uranium deposit have to be to justify the conventional mining method? DAVID MILLER: Near-surface, open-pittable deposits could be as small as a few hundred thousand pounds to be economic if a mill is nearby. To justify a new mill, for example in New Mexico, a critical mass of about 50 million pounds of uranium is needed. Grades can vary greatly. If the deposit is shallow and mined by open pit, with a mill nearby, then grades could be as low as 0.05 percent U3O8. With a 1500 to 2000-foot underground mine, grades above 0.20 percent may be required. STOCKINTERVIEW: How many U.S. uranium deposits do you suspect can be economically mined using conventional methods for less than $65/pound?
DAVID MILLER: There are probably more than one dozen deposits in the U.S. with uranium resources recoverable at less than $65/pound. The resources would likely exceed more than 200 million pounds.