#1Energizing a clean-air world Cameco Investor Presentation#2Carec CCO LISTED CCJ 25 LISTED YEARS TSX NYSE Rachelle Girard Vice-President, Investor Relations 306.956.6403 [email protected] Cory Kos Director, Investor Relations 306.716.6782 [email protected] Cameco www.cameco.com Q1,2024 Financial and outlook information as of April 29, 2024 Mineral Reserve and Resource Estimates as of December 31, 2023 2#3Cameco Energizing a clean-air world Company Overview Q1 2024 Vision and Strategy Cameco Energizing a clean-air world Centered on our values ⚫ Our vision is aligned with the world's growing need for clean, affordable and secure energy solutions. We believe our strategy of contracting discipline, operationally flexible supply discipline, and financial discipline will allow us to achieve our vision of Energizing a clean-air world. Clean Environment Integral to our strategy and Environment Safe, healthy, and rewarding workplace Cameco Energizing a clean-air world reflecting our values, is our commitment to sustainability. ESG Governance tale Social Supportive Communities Cameco First Quarter 2024 2 3#4Cameco Corporation Operating and invested across the nuclear fuel cycle Cigar Lake (54.5%) Saskatchewan, Canada World's Highest-Grade Uranium Mine Licensed Capacity (100%): 18 M lbs/yr Rabbit Lake (100%) Saskatchewan Tier One Uranium Operations McArthur River (69.8%) Key Lake (83.3%) Saskatchewan, Canada The World's Largest, High-Grade Uranium Mine/Mill Licensed Capacity (100%): 25 M lbs/yr Inkai (40%) Kazakhstan A Significant Low-Cost Source of Uranium Licensed Capacity (100%): 10.4 M lbs/yr Tier Two Uranium Assets, Advanced Projects and Exploration US ISR Operations (100%) Nebraska Wyoming Millennium (69.9%) Saskatchewan Yeelirrie (100%) Western Australia Kintyre (100%) Western Australia Athabasca Basin Exploration (100% & JVs) 650,000 Hectares Cameco Energizing a clean-air world Fuel Services Blind River Refinery (100%) Ontario Port Hope Conversion Facility (100%) Ontano Cameco Fuel Manufacturing (100%) Ontario World's Largest Commercial Uranium Refinery Canada's Only Uranium Conversion Facility Manufactures Fuel Bundles and Reactor Components for CANDU Heavy Water Reactors Westinghouse Electric Company (W) Westinghouse (49%) Provider of mission- critical and specialized technologies, products and services across the nuclear power sector Other Nuclear Fuel Cycle Investments Global Laser Enrichment (GLE) (49%) Developing and Testing Third-Generation Laser Enrichment Technology First Quarter 2024 3 Favourable Market Fundamentals Cameco strategically positioned Cameco Energizing a clean-air world Growing Demand Driven By Global focus on: • Energy security • . • . Electrification Decarbonization Country net-zero targets Company net-zero targets • Generative Al carbon footprint • Infrastructure investments • Uncertain Supply Geopolitical/trade policy risk Ongoing transportation issues ⚫ Planned supply curtailments Unplanned supply disruptions ⚫ Underinvestment in existing capacity Underinvestment in new capacity Decreasing secondary supply Cameco is Well-Positioned Strategy captures full-cycle value . • Long-term contract portfolio Operational flexibility Tier-one expansion capacity • Project pipeline - exploration Idled tier-two capacity • Invested across the fuel cycle and reactor life cycle ⚫ Risk managed financial discipline First Quarter 2024 4 4#5Net-zero Carbon Targets Global attention on a triple challenge Cameco Energizing a clean-air world Energy Poverty • Lift 1/3 of the global population out of energy poverty by improving access to clean and reliable baseload electricity Thermal Replacement • Replace up to 80% of the current global grid running on carbon-emitting thermal power with a clean, reliable alternative Electrifying Industry • Global power grids must grow by electrifying key industries (transportation, heating) that are powered with carbon-emitting sources of thermal energy. A total of 28 countries have signed on to the Declaration to Triple Nuclear Energy, recognizing the key role of nuclear energy in achieving global net-zero targets by 2050 Need for Zero-Carbon Energy Source to meet growing electricity demand Nuclear Energy is Expected to Play a Critical Role in Future Power Generation 4 Energy demand is expected to grow at -1% per year to 20401 Fossil fuel retirements due to decarbonization expected to contribute to energy gap that must be filled by other power generation sources Traditional renewables are projected to provide up to 75% of future energy needs, but cannot support 100% of demand due to their intermittent nature and limitations of batteries? Cameco Energizing a clean-air world First Quarter 2024 5 Nuclear Meets All Key Power Generation Objectives Baseload Capacity Factor íí 10 四川 Nuclear CCGT Coal Wind ✓ Solar x ✓ × x Hydro ✓ Low Emissions³ Ability to Add ✓ x ✓ ✓ ✓ ✓ x ✓ ✓ × Additional Capacity 4 Large-Scale Output ✓ ✓ ✓ x x Protected from Fuel ✓ x x x x Supply Interruption Nuclear energy is important to help fill the clean energy gap left by fossil fuels and renewables as well as energy storage limitations Average Levelized Cost of Electricity (US$/MWh) -$40 -$80-$100-$70-$95 -$90 Nuclear Energy Represents a Safe, Reliable and Affordable Source of Baseload Carbon-Free Power IEA World Energy Outlook 2023, International Renewable Energy Agency Global Energy Transformation: A Roadmap to 2050; Based on grams of CO, emitted per kilowatt-hour produced Coal capacity can be increased but expansion is tempered by policy issues Limited availability of additional sites for large-scale hydro development in most countries: Based on output capacity of typical power plants of each type (1,000 MW or higher defined as plants with large-scale output). Based on median levelized costs of electricty by plant category from Projected Costs of Generating Electraty 2020, IEA First Quarter 2024 6 5#6Nuclear's Low-Carbon Advantage Expanding role for nuclear Cameco Energizing a clean-air world 1333[]句 Nuclear for process heat Net Zero Countries and companies: Net-zero carbon targets Baseload H₂ electricity generation 區 Shifting to low- carbon economy- hydrogen 風 IA Small modular reactor-scalable, solutions Transportation: Electrification and decarbonization Growing Support for Nuclear Full-cycle demand continues to improve with ongoing policy support Cameco Energizing a clean-air world Canada-US Nuclear Co-operation Greenbond Framework 5 G7 Nations Nuclear Alliance Canada Diablo Canyon Extension Reactor life extensions Belgium 8 NEW reactors United Kingdom Inflation Reduction 14 NEW reactors Act USA +life extensions France Progressing 6-9 GWe Nuclear Project Poland Carbon-neutral target China EU taxonomy European Union Targeting 22.5 GWe by 2031 India 4 new reactors totalling 5.6 GWe UAE Reversed phase-out South Korea First Quarter 2024 7 Restart 7 more reactors in 2023 or later Exploring next-gen new builds Japan First Quarter 2024 8 6#7Strong Nuclear Power Outlook Increased term contracting, improving market prices Cameco Energizing a clean-air world Growth from New Reactors Demand Increasing Price Increases Across the Fuel Cycle* China 24 Near-Term Asia 10 $120 $100 Uranium Spor Uranium (US$/lb. U,O,) -Uranium Term Reversal of early retirement/closures 196%* $80 $40- • Geopolitical impacts $40 125%* 820 India 7 Jan-21 Jul-21 Jan-22 Jul-22 Jan-23 Jul-43 Jan-24 Clean, secure Africa & Middle East 5 Russia 4 58 Medium- Term energy focus, reactor life-extensions $200 Conv. Spot Conv. Term SWU Spot SWU Term 160%* Eastem Europe 3 reactors under construction $150 215%* Americas 2 Long- Term UK 2 • Reactor new builds and development of small modular and micro reactors $100- Enrichment (USS/SWU) 167%* Conversion (US$/kgU UFJ) 87%* 30 Jan 21 Jul 21 Jan 22 Jul-22 Jan 23 Jul 23 Jan 24 EU Source: IAEA Market Fundamentals Risk shifting to customers *Increase since January 2021 First Quarter 2024 9 Cameco Energizing a clean-air world Durable demand: Producers • Decarbonization & electrification ⚫ ESG focus creating electron accountability •Traditional demand improving (near, mid, long-term) •Energy security focus • Non-traditional demand (SMRS and advanced nuclear reactors) Demand from financial investors driven by intrinsic value of clean energy uranium Risk is shifting to Uranium Customers Uncertain supply: • Low prices resulted in: • Supply curtailments • End of reserve life • Lack of investment in supply development, exploration • Global supply chain challenges Origin risk: geopolitical & trade policy issues Development risk: unproven assets, cost inflation & schedule delays, increasing regulatory and ESG scrutiny First Quarter 2024 10 7#8Origin Concerns Geopolitical developments Cameco Energizing a clean-air world Niger Capacity: 3%-Uranium (down from 4% in recent years) Russian Capacity: 13% -Uranium 25% - Conversion 37% - Enrichment Source-UC 202304 UMO CMO and EMO Data-Base Supply from Russia Origin Disconnect Many nations that need uranium fuel lack domestic supply Cameco Energizing a clean-alr world Americas USA Canada 29mb 19 re reactors minimal production 94 reactors minimal production 7 reactors *Based on 2023 production estimate and current operable reactors *Operable reactors in Asia include 33 in Japan, of which 12 have restarted. Africa & Middle East Europe Kazakhstan Russia minimal production 131 reactors 24mlb 7 reactors State-owned enterprise production April 2024 108mb (total) 0 7mlb 37 reactors 55mb reactors Australia Asia China 4m lb 56 reactors + 22 under construction 11mlb 91 reactors 13mlb reactors First Quarter 2024 12 8 First Quarter 2024 11#9Uranium Market Fundamentals Driving contracting interest, moving toward replacement rate Cameco Energizing a clean-air world Utility Uncovered Uranium Requirements ~2.1 billion lb. through 2040 (~60% uncovered) Million lb. UsO8 400 350- 300 250 200 150 100 50 SPOT TERM 0 2024 2026 2028 2030 2032 2034 Supply Outlook is Uncertain Structural Primary & Secondary Supply Gap Million lb. U₂O 400 350 Demand- Net Zero Nuclear (triple global nuclear capacity by 2050) 300 Requirements 250 200 150 Demand- High Case Demand- Base Case Non-U.S. 100 Primary Supply 50 United States Secondary Supply 0 2036 2038 2040 2008 2012 2016 2020 2024 2028 2032 2036 2040 Source: UxCQ1 2024 Uranium Market Outlook First Quarter 2024 13 Source UxCQ1 2024 Uranium Market Outlook Balanced and Disciplined Strategy Cameco Contract portfolio informs supply decisions Energizing a clean-air world Strategically-aligned contracting discipline ⚫ Strategically patient • long-term contracting Balanced portfolio Optimize market- related portion of portfolio, focus on Marketing protection from commodity volatility . Exposure to improving prices Operationally-flexible supply discipline ⚫ Align production with contract portfolio and customer signals Operations • Strategy Execution Brownfield growth opportunities Financial Leading Sustainability Performance Clean Environment Environment ESG Governance Social Supportive Communities Safe, healthy, and rewarding workplace Risk-managed financial discipline Self-manage risk Supports opportunistic investment in nuclear fuel value chain 100% of our product is used to produce clean, carbon-free, base-load electricity First Quarter 2024 14 9#10Operationally Flexible Supply Align production with market opportunities and contracts Cameco Energizing a clean-air world Spot is NOT the market Spot is thinly-traded, one-time and discretionary • Productive capacity missing the long-term contracting cycle leads to value-destructive spot sales We do not plan our production for spot exposure We are typically over-contracted and are net spot buyers, not spot sellers Contracted sales commitments determine production Long-term value focus • Multi-year requirements layered in during periods of above replacement-rate contracting Exposure to greater returns as prices increase, protected from lows . Diversified, proven and reliable commercial supplier Productive capacity underpinned by contract portfolio into 2030s Investing in operational flexibility Financially disciplined Marketing Cameco is a demonstrated tier-one producer with proven tier- one assets Commercial Marketing Framework Full-Cycle Value = Portfolio & Pipeline Exposure Cameco's long-term, balanced sales portfolio achieves upside exposure, downside protection Terms Market-Related: volume based priced at time of delivery, escalated floors and ceilings ⚫ Base-Escalated: volume based at current prices escalated Cameco Energizing a clean-air world Disciplined production aligned with market opportunities First Quarter 2024 15 Marketing ⚫ Production ⚫ Inventory Sourcing Proven Producer Advantage ⚫ Purchases (spot, long-term) Loans ⚫ Future productive capacity supported by cash flow from long-term contract portfolio, not from dilutive equity raises or significant debt leverage Million lbs U₂O Portfolio Committed sales -20% of reserves & resources Pricing captured in 5-year sensitivity table Pipeline Uncontracted, in-ground inventory -80% of reserves & resources Exposed to rising market prices * Illustrative of framework for long-term contracting, does not reflect actual contracted volumes, all resources may not be converted to reserves. Year First Quarter 2024 16 10#11Future Uranium Supply Production response challenges - proven producer advantages Cameco Energizing a clean-air world Declared Assets Demonstrated Promised Medium Risk Brownfield Producers Volume Risks ⚫ regulatory licensing stakeholder ESG ⚫ Proven Lowest Risk ⚫ inflation & supply-chain ⚫ project execution ⚫ operational Timing Risks ⚫ demand cycle ⚫ geopolitical/realignment Greenfield macroeconomic Highest Risk Restarts Ramp Ups Expansions Cameco: A proven producer with experience and demonstrated assets Cigar Lake Extension McArthur River/Key Lake Growth JV Inkai Growth Rabbit Lake US In-Situ Recovery Yeelirrie/Kintyre Millennium Athabasca Exploration Projects Greenfield Medium Risk US Exploration Projects > > > く KKKK ☐ Permitted Mine KKKKK Proven Mine Infrastructure KKKKKExisting Industrial Infrastructure KKKKKKKKK Existing Mining Workforce Active Long-Term Contracting But remaining selective to maintain exposure to incentive pricing Cameco Energizing a clean-air world Average sales of 28 million lb./year for 2024-2028 Commitments span more than a decade Long-term contracts for -205 million lb. U* >75,000 tonnes UF6* At December 31, 2023 million lb. UOB Total Market Annual Long-term Contracting Volume Cameco Total Future Commitment Level -Cameco 5-year Average Commitment Level @ Dec 31 First Quarter 2024 17 Marketing 350 32 31 30 29 27 300 26 23 24 22 20 20 250 200 150 100 50 50 0 35 29 30 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 25 25 20 115 10 10 5 0 million lb. U₂OB First Quarter 2024 18 11#12Contracting Success Cameco Tier-one supply to match commitments, new phase of supply discipline Energizing a clean-air world M lbs (our share) 2024 Licensed capacity Operations McArthur River/Key Lake 12.6 18 @ 100% 17.5 25 @ 100% 32 M lbs Cigar Lake 9.8 18 @ 100% 9.8 18 @ 100% Inkai (JV Inkal purchase) (In discussion with JV partner) 5.0 12.6 @ 100% (+20% subsoil) (our share of tier-one licensed capacity) <~56 M lbs @ 100% Fuel Services - conversion 12,000 tu 12,500 tu First Quarter 2024 19 Financial Financial Strength Transitioning to tier-one run rate Shifting into a new phase of supply discipline • Categorically positive for Cameco Continued strong margin and cash flow • • • Cameco Energizing a clean-air world Higher level of tier-one production, sourcing from: inventory, loans from storage agreements, pull forward of long-term purchases, opportunistic spot purchases No longer expensing care and maintenance costs or operational readiness costs for McArthur River/Key Lake Market-related portion of contract portfolio exposed to rising uranium prices Uncommitted in-ground inventory exposed to rising uranium prices Enviable balance sheet and positioned to self-manage risk Opportunistic investment in nuclear fuel value chain First Quarter 2024 20 20 12 12#13Financial Strength Risk managed financial discipline Liquidity $323 Million Cash $1 Billion Undrawn credit facility Total debt* $1.5 Billion Credit ratings S&P: BBB- DBRS: BBB "As at March 31, 2024 Cameco Energizing a clean-air world Maintain strong balance sheet • Navigate by investment grade rating • Take advantage of value-adding opportunities as they arise 2024 Capital allocation priorities • Execute production plan and return to tier-one cost structure ⚫ Begin work on Cigar Lake extension • Evaluate expansion at McArthur River/Key Lake • Improve operational effectiveness • Look for an opportunity to refinance June 2024 debenture •In Q1, $200 million (US) partial repayment on floating-rate term loan that was put in place to help fund the acquisition of Westinghouse First Quarter 2024 21 Experienced, Reliable Supplier New contracting cycle is highlighting focus on security of supply Cameco Energizing a clean-air world Security A world leader in low-cost uranium production with a diversified portfolio and extensive reserves and resources Flexibility Best global exploration and advanced project pipeline prepared for growing demand Diversification Operations and investments spanning the nuclear fuel cycle, from exploration to CANDU fuel manufacturing Experience Global leaders in exploration and mining, environmental protection, worker health and safety, with decades of experience across the Fuel Cycle Sustainability Committed to long-term sustainability, clean environment and a safe, healthy and rewarding workplace First Quarter 2024 22 13#14Environment, Social, Governance ESG integrated into all aspects of our business Cameco Energizing a clean-air world To support achieving our 2030 GHG emissions reduction target, we implemented a 2003 compensable target to create tailored decarbonization pathways for each operationally controlled site. We completed cimate change scenario analyses to understand how projected long- term changing climate conditions could impact our employees, assets, and operations in northern Saskatchewan and Ontario, Canada Clean Environment Environment Safe, healthy, and rewarding workplace ESG Governance dale Social Supportive Communities To support our commitment to climate action we joined the Net Zero Nuclear initiative, which calls for collaboration among government, industry leaders and civil society to triple global nuclear capacity to achieve carbon neutrality by 2050. Cameco's board of directors has appointed Chief Tammy Cook Searson and Dominique Minière as board members who will serve on Cameco's Safety, Health, and Environment Committee of the board, which holds oversight for our ESG matters 100% of our product goes to producing clean, carbon-free, base-load electricity Learn more > www.cameco.com/esg First Quarter 2024 23 Our locations Global presence across the fuel cycle Caneco Corporate Headquarters "Seth Ranch Cigar Lake Mine McArthur River Minel Milenium Project Key Lake Mi Rabbit Lake Opin CANADA Highland Operation Crow Butte Operation Columbia Cameco Exploration Cameco Exploration Projects Cameco Fuel Services Cameco HQ Cameco Uranium Operations Global Laser Enrichment Westinghouse HQ Westinghouse Fabrication & Operations CLE Blind River Refinery Port Hope Conversion Facility Cameco Fas Manufacturing Westinghouse Corporate Headquarters Springfields Visteris Nika Operation CAZAD Cameco Energizing a clean-air world Kintyre Project 0 Yoelie Project First Quarter 2024 24 14#15Focus on Value Well positioned for future demand with world-class, tier-one Assets Cameco's Share 485 M lbs Proven & Probable Reserves 409 M lbs Measured & Indicated Resources 153 M lbs Inferred Resources All values shown, including reserves and resources, represent our share only, unless indicated. Please see Cameco's most recent annual management's discussion and analysis (MD&A) for more information about these reserves and resources Cameco Energizing a clean-alr world Extensive reserves and resources ✓ Diversified supply ✓ Decisions driven by contracting success McArthur River/Key Lake The world's largest, high-grade uranium mine Proven and Probable Reserves¹ 265.6 M lbs Cameco's Share 69.8% Average grade U3O8 6.72% Production 2023 production: Cameco Energizing a clean-air world 13.5 M lbs (100% basis) 2024 outlook: 18.0 M lbs (100% basis) 'At December 31, 2023, our share only. See Cameco's 2023 annual management's discussion and analysis (MD&A) for more information about reserves and resources. First Quarter 2024 25 CAUTION FirstQuarter 2024 26 15#16Cigar Lake World-class, high-grade uranium mine Proven and Probable Reserves¹ 113.8 M lbs Cameco's Share 54.5% Average grade U3O8 17.03% Production 2023 production: Cameco Energizing a clean-alr world 15.1 M lbs (100% basis) 2024 outlook: 18.0 M lbs (100% basis) At December 31, 2023. our share only. See Cameco's 2023 annual management's discussion and analysis (MD&A) for more information about reserves and resources. JV Inkai A significant source of low-cost uranium production Proven and Probable Reserves1 104.7 M lbs Cameco's Share +40% Average grade U308 0.04% Production 2023 production: Cameco Energizing a clean-air world 8.3 M lbs (100% basis) 2024 forecast: (In Discussion with JV partner)² At December 31, 2023, our share only. See Cameco's 2023 annual management's discussion and analysis (MD&A) for more information about reserves and resources. #On February 1, 2024, KAP announced that production in Kazakhstan is expected to remain 20% below subsoil use agreements levels, primarily due to a sulfuric acid shortage in the country. We remain in discussions with JV Inkal and KAP to determine how this may impact production in 2024 First Quarter 2024 27 First Quarter 2024 28 16#17Fuel Services Division Refining, conversion and fuel manufacturing Blind River Refinery Port Hope Conversion Facility Cameco Fuel Manufacturing Inc. Cameco Energizing a clean-alr world Cameco's Share 100% Production 2023 production: 13.3 M KgU 2024 outlook: 13.5-14.5 M KgU Westinghouse* Full suite portfolio of nuclear technology & services Develop & Deploy Leading Carbon-Free Technology Cameco Energizing a clean-air world First Quarter 2024 29 Active in All Phases of the Nuclear Operating Plant Lifecycle Installed Base (Operations and Maintenance) Design and Build AP1000 Reactor AP300™ SMR Energy Storage eVinci™ Microreactor Americas PWR EMEA/Asia PWR BWR VVER Outage & Engineering Instrumentation Maint. Svc. Services & Control Parts Provide carbon-free advanced reactor technologies that enable the flex-load, carbon-free grid of the future to commercial and government clients Maintain strong position in PWR and grow BWR, VVER and other advanced fuel capabilities Deployment of innovative digital products and services and increase penetration of OEM and non-OEM parts market Strategic Partnership between Cameco (49%) and Brookfield (51%) First Quarter 2024 30 17#18Westinghouse Acquisition Strategic rationale Cameco Energizing a clean-alr world Brookfield Renewable Westinghouse Platform for Strategic Growth Strategic Partnership: 49% Cameco 51% Brookfield • Creates a platform for strategic growth across the nuclear fuel value chain at time where growth is on the horizon for nuclear energy ⚫ Reinforces Cameco's position as a global champion of the clean energy transition Reliable and Secure Fuel Supplies Complements Cameco's Participation in the Nuclear Fuel Value Chain • Complements Cameco's reliable and secure tier- one uranium assets and fuel services with Westinghouse's global nuclear fuel and plant services platform for light water reactors Accretive on Key Metrics Expected to be Accretive to Cameco . Westinghouse's strong, long-term customer relationships and reliable revenue streams are expected to generate stable cash flow Westinghouse expected to self-fund its approved annual business plans and make distributions to partners . . Participation Across Nuclear Fuel Cycle Expected to enhance Cameco's ability to compete Enhances ability to satisfy existing and new customer needs Investing in nuclear assets like Cameco's: strategic, proven, licensed and permitted, and in geopolitically attractive jurisdictions Enhanced Financial Strength Provides Platform for Further Growth • Expands exposure to areas of the fuel cycle that have historically performed well during varying macroeconomic environments . Cameco expected to maintain financial strength and flexibility to execute on our strategy First Quarter 2024 Global Laser Enrichment Developing 3rd generation laser enrichment technology Cameco Energizing a clean-air world GLE is the exclusive worldwide licensee of the proprietary Separation of Isotopes by Laser Excitation (SILEX) technology • • Cameco is the commercial lead for GLE with a 49% interest (option to attain a majority interest of 75% ownership) Subject to a number of factors1, GLE could offer: ⚫ re-enrichment of depleted US Department of Energy (DOE) tails to natural UF6 ⚫ low-enriched uranium (LEU) for existing and future light-water reactors, including LEU-based SMRS (if a market develops) high-assay low-enriched uranium (HALEU) for advanced reactor designs (if a market develops) ⚫ GLE targeting delivery of Technology Readiness Level 6 (TRL-6) in 2024 • Potential commercial scale deployment in Western Kentucky GLE's path to commercialization depends on several factors, including but not limited to the successful progression and completion of GLE's technology demonstration and maturation program, a clear commercial use case, sound market fundamentals, clarity regarding future Russian fuel imports, the ability to secure substantial government support and funding (specifically, accelerated commercial pathways related to LEU and potentially, HALEU are reliant on government funding) and long-term industry support 31 First Quarter 2024 32 18#19Exploration Focused on the most prospective trends in the Athabasca Basin Cameco Energizing a clean-alr world Alberta Cameco/Joint Venture Exploration Project 417 Saskatchewan * Cameco/Joint Venture Prospect/Deposit Cameco Operation ATHABASCA BASIN Manitoba Millennium Deposit Rabbit Lake Operation (C&M) Cigar Lake Mine Significant land position • 650,000 hectares of Cameco and JV-operated properties History of exploration success ⚫ Uranium prospects and undeveloped deposits on dozens of projects Infrastructure support McArthur River Mine/ Key Lake Mill • Existing mines and mills provide logistical and economic advantages Nuclear Fuel Cycle Much more than mining AA LIGHT WATER REACTORS >>> CONVERSION OF UO, to UF ENRICHMENT OF UF Clobal Laser Enrichment In develcement EXPLORATION MINING MILLING OF USO Cameco explores, mines and mills in Saskatchewan, the USA, Australia and Kasakutan REFINING USO Blind River Refining Facility World's largest commercial wanium refinery CONVERSION Port Hope Conversion Facility Canada's only uranium comersion facility CAMECO CAMECO INVESTMENTS HEAVY WATER REACTORS (CANDU) >>> DOO CONVERSION OF ENRICHED UF into UO Cameco Energizing a clean-air world First Quarter 2024 33 FUEL FABRICATION LIGHT WATER REACTORS SPENT FUEL STORAGE Westinghouse (f) ENERGY GRID Useable clean energy that powers homes, hospitals and businesses CONVERSION OF UO, to UO₂ FUEL FABRICATION Port Hope & Cobourg Fuel Manufacturing Facilities Manufactures reactor components and fuel bundles for CANDU reactors CANDU REACTORS SPENT FUEL STORAGE First Quarter 2024 34 19#20Additional Mine Information and Reference Figures Cameco 20#2121 McArthur Athabasca Uranium Deposit Model Millennium Eagle Point Faults Cigar Uranium mineralization Alteration halo Athabasca sandstone Qtzitic/arkosic gneiss Pelitic gneiss (graphitic) Pelitic gneiss Archean "granite" gneiss Cameco#22McArthur River - Raise Bore Mining System Freezing Pilot hole Reaming head Reaming head Backfill cement Staggered raises Cameco 22 22#23Surface freeze plant Heat exchanger A McArthur River - Ground Freezing Heat exchanger B To/from freezewall B Pump Cold brine to Freezewall A Warm brine from Freezewall A Warm brine from Freezewall B Cathedral freezewall Cameco McArthur River - Underground Ore Processing From raise bore To ore loadout on surface Grizzly screen Grinding mill Sorted ore Grizzly X * Ore slurry hoisting pump Ore slurry hoisting pump Thickener Grinding mill Thickener Cameco 23#24sandstone Cigar Lake - Jet Bore Mining System (JBS) Detail A uranium orebody unconformity basement rock Water jet Blade screen Slurry ⚫ Orebody frozen prior to mining • Ore removed using high-pressure water jet · • Cavity monitored using survey equipment ⚫ Cavity backfilled with concrete ⚫ Ore slurry contained to control radiation, eliminate dust mining cavity backfilled cavities Detail A high-pressure water jet rod cars drilling car slurry car drawing not to scale storage ROM to underground processing Cameco 24#25Cigar Lake - Underground Ore Processing From Jet Boring Machine Clamshell To ore loadout on surface ROMS North ROM South ROM Ore slurry hoisting pump Ore slurry hoisting pump Ball mill Crusher ☑ Ball mill Clarifier Clarifier Cameco Cigar Lake - New Austrian Tunneling Method (NATM) Top-Heading Internal Support Advantages •Adaptive ground support, varies with rock strength • Smaller amount of area open and unsupported ground at any given time . Yielding elements absorb stress in a controlled, measured manner Invert Internal Support Comparison Overall time to develop a cross cut similar to tunnel boring NATM advance rate is slower, but setup and finish steps are faster Costs are similar between the two methods Cameco 25#26Freeze hole detail Cigar Lake - Surface Freezing Detail Surface freeze cross section Freeze plant Overburden Jet boring holes Return tubing JBS production tunnels 26 Supply tubing- Surface Freeze plant Chilled brine- Surface freeze Warm brine Freeze hole specifications ⚫462 m long, overburden to ~40 m .~8-10 days/drill hole ⚫required accuracy of ~1.5 m 100-120 holes/production panel Timeline .~1.5-2 years to drill, outfit and activate a production panel ⚫freezing takes 2-5 years, depending on hole spacing and ground conditions -465 m Cameco Cameco Drill hole colour key Active freeze holes Drilled freeze holes Cigar Lake - Surface Freezing#2727 Soil Permeable sands, clays and gravels Upper confining layer Host sandstone Uranium roll-front Lower confining layer Lower aquifer Uranium bearing solution Negative pressure Injection well Production well Monitoring well In-Situ Recovery Process (water + oxygen + carbon dioxide in US, acid in Kazakhstan Production fluid Screens and submersible pumps Well cover Recycled from ion exchange To ion exchange Cameco#28Mineral reserves As of December 31, 2023 (100% - only the shaded column shows our share) PROVEN AND PROBABLE (tonnes in thousands; pounds in millions) PROVEN MINING GRADE PROPERTY METHOD TONNES % U308 CONTENT (LBS U3O8) TONNES PROBABLE GRADE % U308 TOTAL MINERAL RESERVES CONTENT GRADE CONTENT OUR SHARE RESERVES CONTENT METALLURGICAL Cigar Lake UG 338.1 18.11 135.0 217.5 15.36 (LBS U3O8) 73.7 TONNES % U308 (LBS U3O8) (LBS U3O8) RECOVERY (%) 555.6 17.03 208.6 113.8 98.7 Key Lake OP 61.1 0.52 0.7 61.1 0.52 0.7 0.6 95.0 McArthur River UG 2,047.3 7.02 316.8 Inkai ISR 239,588.4 0.04 208.8 520.7 66,046.9 5.55 63.8 0.04 52.9 2,568.0 305,635.3 0.04 6.72 380.5 265.6 99.0 261.7 104.7 85.0 Total 242,035.0 661.2 66,785.0 190.3 308,820.1 851.5 484.7 (UG underground, OP - open pit, ISR - in situ recovery) Note that the estimates in the above table: use a constant dollar average uranium price of approximately $54 (US) per pound U308 • are based on exchange rates of $1.00 US-$1.26 Cdn and $1.00 US-450 Kazakhstan Tenge Our estimate of mineral reserves and mineral resources may be positively or negatively affected by the occurrence of one or more of the material risks discussed under the heading Caution about forward-looking information beginning on page 29, as well as certain property-specific risks. Please see our mineral reserves and resources section of our most recent annual information form for the specific assumptions, parameters and methods used in the estimate of Cigar Lake, McArthur River, and Inkai mineral reserves. Metallurgical recovery We report mineral reserves as the quantity of contained ore supporting our mining plans and provide an estimate of the metallurgical recovery for each uranium property. The estimate of the amount of valuable product that can be physically recovered by the metallurgical extraction process is obtained by multiplying the quantity of contained metal (content) by the planned metallurgical recovery percentage. The content and our share of uranium in the table above are before accounting for estimated metallurgical recovery. 28#29Mineral resources As of December 31, 2023 (100% - only the shaded columns show our share) MEASURED, INDICATED AND INFERRED (tonnes in thousands; pounds in millions) MEASURED RESOURCES (M) INDICATED RESOURCES (1) PROPERTY Cigar Lake TONNES GRADE CONTENT % U3O8 (LBS U308) TONNES GRADE CONTENT % U3O8 (LBS U308) TOTAL M+I CONTENT (LBS U308) 86.3 5.32 10.1 143.6 5.33 16.9 27.0 OUR SHARE TOTAL M+1 CONTENT (LBS U308) 14.7 INFERRED RESOURCES OUR SHARE INFERRED GRADE CONTENT CONTENT TONNES % U3O8 (LBS U308) (LBS U308) 163.4 5.55 20.0 10.9 Fox Lake 386.7 7.99 68.1 53.3 Kintyre 3,897.7 0.62 53.5 53.5 53.5 517.1 0.53 6.0 6.0 McArthur River 78.7 2.27 3.9 60.6 2.30 3.1 7.0 4.9 37.2 2.90 2.4 1.7 Millennium 1,442.6 2.39 75.9 75.9 53.0 412.4 3.19 29.0 20.2 Rabbit Lake 1,836.5 0.95 38.6 38.6 38.6 2,460.9 0.62 33.7 33.7 Tamarack 183.8 4.42 17.9 17.9 10.3 45.6 1.02 1.0 0.6 Yeelirrie 27,172.9 0.16 95.9 12,178.3 0.12 32.2 128.1 128.1 Crow Butte 1,558.1 0.19 6.6 939.3 0.35 7.3 13.9 13.9 531.4 0.16 1.8 1.8 Gas Hills Peach 687.2 0.11 1.7 3,626.1 0.15 11.6 13.3 13.3 3,307.5 0.08 6.0 6.0 Inkai 87,192.7 0.03 56.1 65,236.0 0.02 32.9 89.1 35.6 36,165.2 0.03 23.9 9.6 North Butte - Brown 604.2 0.08 1.1 5,530.3 0.07 8.4 9.4 9.4 294.5 0.06 0.4 0.4 Ranch Ruby Ranch 2,215.3 0.08 4.1 4.1 4.1 56.2 0.13 0.2 0.2 Shirley Basin 89.2 0.15 0.3 1,638.2 0.11 4.1 4.4 4.4 508.0 0.10 1.1 1.1 Smith Ranch - Highland Total Note that mineral resources: 3,703.5 121,172.8 0.10 7.9 14,372.3 0.05 17.0 24.9 24.9 6,861.0 0.05 7.7 7.7 183.7 113,300.7 323.4 507.1 408.8 51,747.1 201.3 153.2 • do not include amounts that have been identified as mineral reserves • do not have demonstrated economic viability • totals may not add due to rounding 29#30Caution About Forward-Looking Information Statements contained in this presentation include statements and information about our expectations for the future. When we discuss our strategy, plans and future financial and operating performance, or other things that have not yet taken place, we are making statements considered to be forward-looking information or forward-looking statements under Canadian and U.S. securities laws. They represent our current views and can change significantly. These statements are based upon a number of material assumptions, which may prove to be incorrect. Actual results and events may be significantly different from what we currently expect because of the risks associated with our business. We recommend that you review our most recent annual and any subsequent quarterly management's discussion and analysis for more information about these assumptions and risks. You should also review our current annual information form, which includes a discussion of other material risks that could cause actual results to differ significantly from our current expectations. Forward-looking information is designed to help you understand management's current views of our near and longer-term prospects, and it may not be appropriate for other purposes. We will not necessarily update this information unless we are required to by securities laws. Examples of forward-looking information that may appear in this presentation include: our expectations regarding future world electricity consumption and costs; our expectations regarding the demand for nuclear energy, and the benefits of nuclear power; statements regarding uranium supply, demand, consumption, production, long-term contracting, prices and market conditions, the reasons for those expectations and the risks associated with them; our ability to respond to changing market conditions; our plans and outlook; production forecasts and other expectations regarding our uranium properties and our fuel services division; our investments in nuclear technology and services; mineral reserve and mineral resource estimates; the outcome of litigation or other disputes; and our market position and prospects for increasing shareholder value. The material risks that could cause actual results to vary include: uranium prices decline due to reduced demand for nuclear energy or other causes; we are not successfully able to manage our costs, risks and operations; we are adversely affected by changes in currency exchange rates, interest rates, royalty rates, or tax rates; our production costs are higher than planned; necessary supplies are not available, or not available on commercially reasonable terms; our estimates of production, purchases, costs, cash flow, decommissioning, reclamation expenses, or our tax expense prove to be inaccurate; we are unable to enforce our legal rights under our existing agreements, permits or licences; we are subject to litigation or arbitration that has an adverse outcome; there are defects in, or challenges to, title to our properties; our mineral reserve and resource estimates are not reliable; there are unexpected or challenging geological, hydrological or mining conditions at uranium properties; we are affected by environmental, safety and regulatory risks, including increased regulatory burdens or delays; necessary permits or approvals from government authorities cannot be obtained or maintained; we are affected by political risks; we are affected by a widespread health crisis, terrorism, sabotage, blockades, civil unrest, social or political activism, accident or a deterioration in political support for, or demand for, nuclear energy; we are impacted by changes in the regulation or public perception of the safety of nuclear power plants; government regulations or policies that adversely affect us, including tax and trade laws and policies; our uranium or other suppliers or purchasers fail to fulfil commitments; development, mining or production plans are delayed or do not succeed for any reason; the nuclear technology or services we have invest in prove to be less profitable than we expect; the risk our estimates and forecasts prove to be inaccurate; the risk our strategies are unsuccessful or have unanticipated consequences; we are affected by natural phenomena, including inclement weather, fire, flood and earthquakes; operations are disrupted due to problems with facilities, the unavailability of reagents, equipment, operating parts and supplies critical to production, equipment failure, lack of tailings capacity, labour shortages, labour relations issues, strikes or lockouts, underground floods, cave-ins, ground movements, tailings dam failures, transportation disruptions or accidents, or other development and operating risks. We have made material assumptions regarding: our ability to manage our costs, risks and operations; sales and purchase volumes and prices for uranium and fuel services; trade restrictions; that counterparties to our sales and purchase agreements will honour their commitments; the demand for and supply of uranium; the absence of adverse changes in regulation or in the 30#31public perception of the safety of nuclear energy; our ability to continue to supply our products and services in the expected quantities and at the expected times; production levels; costs, including production and purchase costs; the success of our plans and strategies; market conditions and other factors upon which we have based our plans and outlook; spot prices and realized prices for uranium; tax rates and payments, royalty rates, currency exchange rates and interest rates; the successful outcome of any litigation or arbitration claims; our development, mining, and other expenses; the reliability of our mineral reserve and resource estimates; our understanding of the geological, hydrological and other conditions at uranium properties; the success of development, mining and production plans; our and our contractors' ability to comply with current and future environmental, safety and other regulatory requirements, and to obtain and maintain required regulatory approvals; the profitability of our nuclear technology and services investments; our operations not being significantly disrupted as a result of a widespread health crisis, political instability, nationalization, terrorism, sabotage, blockades, civil unrest, breakdown, natural disasters, governmental or political actions, litigation or arbitration proceedings, or by the unavailability of reagents, equipment, operating parts and supplies critical to production, labour shortages, labour relations issues, strikes or lockouts, underground floods, cave-ins, ground movements, tailings dam failure, lack of tailings capacity, transportation disruptions or accidents, or other development or operating risks. General Disclaimer This Investor Handout does not constitute an offer to sell, or a solicitation of an offer to buy, any securities. It is not intended for distribution in any jurisdiction where its distribution would be prohibited by law. In providing this Investor Handout, we do not undertake any obligation to update it, and the information contained in it is subject to change. Any information from a third party source that is quoted in this Investor Handout should not be considered to be adopted or endorsed by Cameco, and has not been independently verified by us. This Investor Handout does not contain all information important for investors, and you are urged to review Cameco's annual, quarterly and other disclosure documents available on our website and at 1. Important information for US investors We present information about mineralization, mineral reserves and resources as required by National Instrument 43-101 - Standards of Disclosure for Mineral Projects of the Canadian Securities Administrators (NI 43-101), in accordance with applicable Canadian securities laws. As a foreign private issuer filing reports with the US Securities and Exchange Commission (SEC) under the Multijurisdictional Disclosure System, we are not required to comply with the SEC's disclosure requirements relating to mining properties. Investors in the United States should be aware that the disclosure requirements of NI 43-101 are different from those under applicable SEC rules, and the information that we present concerning mineralization, mineral reserves and resources may not be comparable to information made public by companies that comply with the SEC's reporting and disclosure requirements for mining companies. 31#32Qualified persons The technical and scientific information discussed in this presentation for our material properties (McArthur River/Key Lake, Cigar Lake and Inkai) was approved by the following individuals who are qualified persons for the purposes of NI 43-101: MCARTHUR RIVER/KEY LAKE • Greg Murdock, general manager, McArthur River, Cameco Daley McIntyre, general manager, Key Lake, Cameco • Alain D. Renaud, principal resource geologist, technical services, Cameco • Biman Bharadwaj, principal metallurgist, technical services, Cameco CIGAR LAKE • Lloyd Rowson, general manager, Cigar Lake, Cameco Scott Bishop, director, technical services, Cameco Alain D. Renaud, principal resource geologist, technical services, Cameco Biman Bharadwaj, principal metallurgist, technical services, Cameco ΙΝΚΑΙ Alain D. Renaud, principal resource geologist, technical services, Cameco Scott Bishop, director, technical services, Cameco . • Biman Bharadwaj, principal metallurgist, technical services, Cameco Sergey Ivanov, deputy director general, technical services, Cameco Kazakhstan LLP 32#33The nuclear fuel cycle. CANDU Cycle Light Water Cycle 5 Mining Once an orebody is discovered and defined by exploration, there are three common ways to mine uranium, depending on the depth of the orebody and the deposit's geological characteristics: • Open pit mining is used if the ore is near the surface. The ore is usually mined using drilling and blasting. • Underground mining is used if the ore is too deep to make open pit mining economical. Tunnels and shafts provide access to the ore. • In situ recovery (ISR) does not require large scale excavation. Instead, holes are drilled into the ore and a solution is used to dissolve the uranium. The solution is pumped to the surface where the uranium is recovered. Enrichment Uranium is made up of two main isotopes: U-238 and U-235. Only U-235 atoms, which make up 0.7% of natural uranium, are involved in the nuclear reaction (fission). Most of the world's commercial nuclear reactors require uranium that has an enriched level of U-235 atoms. The enrichment process increases the concentration of U-235 to between 3% and 5% by separating U-235 atoms from the U-238. Enriched UF6 gas is then converted to powdered UO2. Fuel manufacturing Natural or enriched UO2 is pressed into pellets, which are baked at a high temperature. These are packed into zircaloy or stainless steel tubes, sealed and then assembled into fuel bundles. 1 Milling Ore from open pit and underground mines is processed to extract the uranium and package it as a powder typically referred to as uranium concentrates (U30g) or yellowcake. The leftover processed rock and other solid waste (tailings) is placed in an engineered tailings facility. 2 Refining Refining removes the impurities from the uranium concentrate and changes its chemical form to uranium trioxide (UO3). Conversion For light water reactors, the UO3 is converted to uranium hexafluoride (UF6) gas to prepare it for enrichment. For heavy water reactors like the CANDU reactor, the UO3 is converted into powdered uranium dioxide (UO₂). 6 Generation Nuclear reactors are used to generate electricity. U-235 atoms in the reactor fuel fission, creating heat that generates steam to drive turbines. The fuel bundles in the reactor need to be replaced as the U-235 atoms are depleted, typically after one or two years depending upon the reactor type. The used - or spent - fuel is stored or reprocessed. Spent fuel management The majority of spent fuel is safely stored at the reactor site. A small amount of spent fuel is reprocessed. The reprocessed fuel is used in some European and Japanese reactors.#34Energizing a clean-air world Cameco 34