Ventilation Requirements for Uranium Mines Rabbit Lake Operation Presented by: Cristian Gherghel, P. Eng. Mine Engineer, Eagle Point Mine

Outline  Introduction  Ventilation Design Factors  Ventilation Planning at Rabbit Lake Operation The Rabbit Lake Ventilation System The Rabbit Lake Ventilation System Ventilation Management and Operating Practices Ventilation Management and Operating Practices Daily Operating Inspections Daily Operating Inspections Ventilation Surveys and Gas Monitoring Ventilation Surveys and Gas Monitoring Continuous Working Level Monitors Continuous Working Level Monitors Auxiliary ventilation Auxiliary ventilation Operating Practices for ore development and Production Operating Practices for ore development and Production

Rabbit Lake Operation Rabbit Lake Rabbit Lake Operation Location Map

Introduction - Mine Portal  Reserves: 19.1 million lbs U 3 O 8  2006 Production: 5.1 million lbs

Introduction - Eagle Point Mine GranitoidDome Mine Portal Main Decline MetaSediments 1000m E.A.R. E.A.R 03 Zone 040 Zone 163 ZONE 144 Zone 02 Next FW ZONE 02 Next ZONE

Introduction – Protecting Worker Exposure

Introduction - Protecting Worker Exposure - Radiation Protection  Dilute radon progeny to maximum exposure of 4 WLM  Maintain radon progeny below 0.1 WL in working areas  Reduce radon gas exposure limit – new monitoring system  Train underground personnel in the importance of proper ventilation Challenges for ventilation engineer:

Introduction – Ventilation planning  Single pass ventilation  Proper sequencing of the development and the stopes

Ventilation Design Factors  Diesel emission  Flexibility  Single pass ventilation  Retreat mining method  Fresh air mining workings in waste rock  Sealing old working areas to minimize leakage  Water grouting

Ventilation Design Factors  Flexibility to adapt to the mining conditions: O3 zone water inflow

Ventilation Design Factors Dividing mining areas in ventilation blocks

Eagle Point Mine – Ventilation System

Ventilation planning - Eagle Point U/G Mine

15 to 30 m Remote Mucking CRF Ventilation Planning - Longhole Stoping

Ventilation planning – typical stope design

Ventilation Planning - SBM drilling Ventilation Planning - SBM drilling

Ventilation planning - Longhole Drilling – workers on fresh air in the overcut drift

Ventilation planning - modeling

Ventilation Management  Ventilation Management Procedure  Ventilation surveys  Vent Directives  Auxiliary ventilation  Sumps, Remucks and TTA  Underduct flows  Access in the levels from the main ramp  Minimum flows required  Main fans failure

Vent surveys  Weekly Volumetric Vent surveys  Pressure surveys  Gas monitoring: CO, CO2, NO2, 02

Ventilation Management  Radon progeny  Radon gas Radiation Code of Practice

Radon Progeny Working level ranges for alphanuclear prism lights.  Prism Light Range  Green ≤0.10 WL  Green & Amber 0.11 to 0.25 WL  Amber 0.25 to 0.50 WL  Amber & Red 0.51 to 1.00 WL  Red or Red with white strobe >1.0 WL

Radon Gas Code of Practice for Radon Gas  Prism Light Range  Green ≤3,000 Bq/m^3  Green & Amber 3,000 to 15,000 Bq/m^3  Amber 15,000 to 50,000 Bq/m^3 (RWP and signs)  Amber & Red 50,000 to 60,000 Bq/m^3  Red >60,000 Bq/m^3

Monitoring: DDDDaily WL readings GGGGamma Surveys TTTTime cards TTTT.L.D. badges & DRD’s PPPPersonal Dust Pumps PPPPAD’s (for underground) AAAAlpha Nuclear Monitors (cam) BBBBio-assay sampling

Monitoring – TLD and DRD  T.L.D. Badges Thermo-luminescent Dosimeters Thermo-luminescent Dosimeters records actual exposure to Gamma records actual exposure to Gamma and Beta radiation and Beta radiation National Dose Registry National Dose Registry  DRD’s - Direct Reading Dosimeters - Shows gamma dose for period worn - Counts are recorded daily

Monitoring - PAD  PAD’s Personal Alpha Dosimeters Personal Alpha Dosimeters Worn by all underground personnel (daily) Worn by all underground personnel (daily) Measures Alpha exposure and LLRD for the month period Measures Alpha exposure and LLRD for the month period Loss or contamination requires immediate reporting Loss or contamination requires immediate reporting Must be recharged daily Must be recharged daily

Monitoring - Prisms  Alpha Nuclear Monitors Continuous air samplers Continuous air samplers Measures Alpha activity Measures Alpha activity Has a 10 minute cycle Has a 10 minute cycle Working levels are displayed as colored lights Working levels are displayed as colored lights Follows Code of Practice Levels Follows Code of Practice Levels Red – leave area immediately Red – leave area immediately

Operating practices  Single pass ventilation  Shotcreting – Gamma radiation below 10 microSV/h  Shotcreting – Applied remotely  Stope mucking – Remote control scooptram  Sill covered with crushed rock – min 30 cm  Push auxiliary ventilation system  Water grouting  Sump, TTA and remucks under negative pressure  Vent tubing – minimum 30 m from the face

Operating practices

Conclusions  Eagle Point Mine – effective management program  Key practices:  proper monitoring of the ventilation system in all stages  effective control of the radiation sources  a proactive attitude

Questions?