Cigar Lake Operation Northern Saskatchewan, Canada National Instrument 43-101 Technical Report Effective Date: December 31, 2015 Date of Technical Report: March 29, 2016 PREPARED FOR CAMECO CORPORATION BY: C. SCOTT BISHOP, P. ENG. ALAIN G. MAINVILLE, P. GEO. LESLIE D. YESNIK, P. ENG. Table of Contents 1 SUMMARY ........................................................................................................................................... 1 1.1 Preamble .................................................................................................................................... 1 1.2 Introduction ................................................................................................................................. 2 1.3 Property tenure ........................................................................................................................... 2 1.4 Location and site description ...................................................................................................... 3 1.5 Geology and mineralization ........................................................................................................ 3 1.6 Exploration of Cigar Lake deposit ............................................................................................... 4 1.7 Mineral resources and mineral reserves ..................................................................................... 4 1.8 Mining ......................................................................................................................................... 7 1.9 Processing .................................................................................................................................. 9 1.10 Environmental assessment and licensing ................................................................................... 10 1.11 Cigar Lake water inflow incidents and remediation .................................................................... 11 1.12 Current status of development ................................................................................................... 12 1.13 Production plan .......................................................................................................................... 12 1.14 Economic analysis and costs ..................................................................................................... 14 1.15 Mining and milling risks .............................................................................................................. 14 1.16 Conclusions and recommendations ........................................................................................... 14 2 INTRODUCTION ................................................................................................................................ 18 2.1 Introduction and purpose ............................................................................................................ 18 2.2 Report basis ............................................................................................................................... 18 3 RELIANCE ON OTHER EXPERTS ............................................................................................. 20 4 PROPERTY DESCRIPTION AND LOCATION ....................................................................... 21 4.1 Location ...................................................................................................................................... 21 4.2 Mineral tenure ............................................................................................................................ 23 4.3 Surface tenure ............................................................................................................................ 25 4.4 Royalties ..................................................................................................................................... 27 4.5 Known environmental liabilities .................................................................................................. 27 4.6 Permitting ................................................................................................................................... 27 5 ACCESSIBILITY, CLIMATE, LOCAL RESOURCES, INFRASTRUCTURE AND PHYSIOGRAPHY .......................................................................... 28 5.1 Access ........................................................................................................................................ 28 5.2 Climate ....................................................................................................................................... 30 5.3 Physiography .............................................................................................................................. 30 5.4 Local resources .......................................................................................................................... 30 5.5 Mine and infrastructure ............................................................................................................... 31 i 6 HISTORY ............................................................................................................................................... 34 6.1 Ownership .................................................................................................................................. 34 6.2 Exploration and development history ......................................................................................... 35 6.3 Historical mineral resource and mineral reserve estimates ........................................................ 36 6.4 Historical production ................................................................................................................... 36 7 GEOLOGICAL SETTING AND MINERALIZATION .............................................................. 37 7.1 Regional geology ........................................................................................................................ 37 7.2 Local geology ............................................................................................................................. 37 7.3 Property geology ........................................................................................................................ 41 7.4 Mineralization ............................................................................................................................. 44 8 DEPOSIT TYPES .............................................................................................................................. 45 9 EXPLORATION ................................................................................................................................................... 46 9.1 AREVA 1980 – present .............................................................................................................. 46 9.2 Cameco 2007 – present ............................................................................................................. 51 10 DRILLING ............................................................................................................................................ 52 10.1 Surface drilling ............................................................................................................................ 52 10.2 Underground drilling ................................................................................................................... 57 10.3 Factors that could materially affect the accuracy of the results .................................................. 59 11 SAMPLE PREPARATION, ANALYSES AND SECURITY .................................................. 60 11.1 Sample density and sampling methods ...................................................................................... 60 11.2 Core recovery ............................................................................................................................. 60 11.3 Sample quality and representativeness ...................................................................................... 61 11.4 Sample preparation by Cameco employees ............................................................................... 61 11.5 Sample preparation .................................................................................................................... 61 11.6 Assaying ..................................................................................................................................... 62 11.7 Radiometric surveying ................................................................................................................ 63 11.8 Density sampling ........................................................................................................................ 63 11.9 Quality assurance / quality control .............................................................................................. 64 11.10 Adequacy of sample preparation, assaying, QA/QC and security .............................................. 68 12 DATA VERIFICATION ..................................................................................................................... 70 13 MINERAL PROCESSING AND METALLURGICAL TESTING ......................................... 71 13.1 Cigar Lake processing metallurgical test work ........................................................................... 71 13.2 McClean Lake processing metallurgical test work