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PFN Technology: “ Prompt Fission Neutron”

SXR. Southern Cross Resources Inc. PFN Technology: “ Prompt Fission Neutron”. Deposit Evaluation. 214 Pb. 214 Bi. 238 U. PFN: Disequilibrium Problem. Gamma is the traditional tool used to measure eU 3 O 8 grade and evaluate resources…. g. Gamma Ray Intensity.

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PFN Technology: “ Prompt Fission Neutron”

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  1. SXR Southern Cross Resources Inc PFN Technology:“Prompt Fission Neutron” Deposit Evaluation

  2. 214Pb 214Bi 238U PFN: Disequilibrium Problem Gamma is the traditional tool used to measure eU3O8 grade and evaluate resources… g Gamma Ray Intensity …but in some Roll-front deposits uranium is not in equilibrium with its daughters as they are too young.

  3. PFN: Schematic Gamma Response Hole 1 Hole 2 Hole 3 Hole 4 Overlying Clay Oxidised Aquifer Reduced Aquifer Nose Uranium Ore Tails Basement Clay Gamma Response

  4. PFN: Schematic PFN Response Hole 1 Hole 2 Hole 3 Hole 4 No PFN response in low grade tails as daughters only PFN response directly measures 235U concentrated in high grade nose

  5. PFN: What is PFN Technology? Down Hole Probe Pulsed Neutron Source Drill Hole

  6. PFN: Neutron Generator Tube • High voltage accelerates deuterium (2H) ions into a tritium (3H) target • 2H + 3H  n + 4He (En = 14.2MeV) • Pulses at 1000 cycles per second & emits ~108 neutrons per second

  7. PFN: What is PFN Technology Down Hole Probe 14 MeV Neutron Flux Epithermal Neutron To Thermal Neutron (by Collision with rock) Pulsed Neutron Source Thermal Neutrons Induce Slow Fission of Natural 235U in rocks 2MeV Prompt Neutrons emitted from 235U fission Epithermal & Thermal Neutron Detectors Ratio gives % 235U Drill Hole

  8. PFN Results Thermal Neutron Flux 3.52 U3O8 lbs/ft3 Epithermal Neutron Flux 1.48 U3O8 lbs/ft3 0.27 U3O8 lbs/ft3 • Ratio of Epithermal to Thermal Neutrons is Directly Proportional to 235U • Only 235U is Fissionable in the Natural Environment • Deposits considered in Isotopic Equilibrium 0.72% 235U • 99.27% 238U

  9. PFN: Calibration

  10. PFN Calibration Results

  11. Wireline Log Output Induction & Guard - Define lithology by measuring porosity using EM and Electrical methods. Similar to SP / Resistivity but better suited to highly saline conditions eU3O8 (Black) - Calculated from calibrated natural gamma using a number of factors) Natural Gamma - Total count natural gamma radiation measured by up to three scintillometers with varying NaI crystals sizes pU3O8 (Red) - Direct measure of U235 insitu using ration of epithermal to thermal neutrons – PFN

  12. PFN: Advantages • Crucial for most Tertiary Uranium deposits as they are young and suffer extreme disequilibrium • Uses a safe neutron generator rather than a radioactive source • Produces an accurate direct measurement of insitu uranium over narrow intervals • Results are instantaneous • Measures a large sample volume (500mm sphere) • Obviates the need to drill core • Can be used during ISL mining to quantify recovery • Exploration tool – disequilibrium vector towards mineralisation Colin Skidmore (October 2005) cskidmore@sxru.com

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