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Liberty Mining, LLC <br />DRMS 110 -d Permit Application <br />October 2013 <br />For the Liberty Mine, this is calculated based on ton/ft' Compared with other uranium mines, <br />it is anticipated that the Liberty Mine will produce a normal to low amount of waste rock ( <225 <br />tons per day). Thus, it can be assumed that the applied stress level will be normal to low. <br />8. Definition of failure conditions (drained or un- drained) and degree of saturation: Based on <br />historical data and recent exploration drilling, the Liberty Mine is a dry mine. The waste rock <br />will likely have little to no moisture. Additionally, waste rock stockpiled on the surface will have <br />minimal effects from the low annual precipitation at the mine. Based on the known <br />characteristics of the waste rock pile, most of these parameters indicate that the internal <br />angle of friction will be normal to high. Triaxial strength testing of large size (up to 200 mm) <br />rock fill particles, similar to those found in mine waste rock piles, have internal friction angles <br />in the range of 400 to 50 °, the lower end of the range corresponding to fine - grained material, <br />and the upper end of the range corresponding to coarse - grained material (Leps, 9970). <br />Angle of Repose <br />Recommended maximum angle of repose for waste dumps are: <br />(i) unweathered rock- I(V): 1.75(H) <br />(ii) weathered rock, overburden, up to 15m high- I(V): 2.5(H) <br />(iii) weathered rock, overburden, greater than 15m high- 1(V): 3(H) <br />Based on Bureau of Land Management reclamation regulations, the Liberty Mine will strive to <br />have maximum slope angles less than or equal to 1(V): 3(H). The waste rock pile will be <br />graded at 1(V): 3(H), or 18.43° (- ii above). This places the waste pile well within the <br />recommended range. <br />Foundation Stability <br />The foundation of the waste rock pile is a well compacted surface with substantial sandstone <br />formations beneath. The surface soils have high clay content. The hydrogeology of the area <br />suggests that there are no known aquifers under the pile or in the immediate vicinity. <br />Therefore, there is no water that could enter the pile from below and compromise the stability <br />of the underlying soils or the waste rock pile itself. <br />Factor of Safety (FS) <br />For infinite slopes consisting of cohesionless soils that are either above the water table or <br />that are fully submerged, the factor of safety for slope stability is determined as follows: FS = <br />tan- /tan- where: <br />• = the angle of internal friction for the soil <br />• =the slope angle relative to the horizontal <br />(WSDOT Geotechnical Design Manual 10) <br />There could be a small amount of cohesion which would add to the strength, but this will be <br />ignored in order to calculate the worst case scenario. <br />FS =tan (40 °) /tan (18.43 °) = 2.518 <br />Liberty Mining, LLC Moab, Utah SMA Ref. 5821897 Page 16 <br />