Uranium market update The market in the first quarter of 2015 changed little from the last quarter of 2014. The modest level of contracting activity was comparable to the previous quarter, with no significant strength or weakness emerging.

On the positive side, China started approving new reactor projects after a hiatus following the 2011 events in Japan, and four reactors under construction in China joined the grid. As a result, China now has 26 reactors operating and 23 under construction. On the supply side, production issues at several large uranium mines threaten to tighten supply in the coming year, although the market impact has not yet been significant.

Japan continued to experience difficulties with reactor restarts in 2015, although the country reported a mix of both negative and positive developments. The industry experienced another potential setback with the recent court injunction preventing the restart of Kansai Electric’s two Takahama units, which had applied for restart and had already met the Nuclear Regulatory Authority’s new safety standards. This development adds to ongoing uncertainty about the pace of restarts in Japan. Additionally, it was announced that five older reactors would not submit restart applications, but would be permanently retired. However, positive news also emerged when a provisional injunction to block the restart of the Sendai reactors was rejected by the Kagoshima District Court, allowing Kyushu Electric to remain focused on the safe restart of the facility. The frontrunners for restart continue to be the two Sendai reactors, which appear poised for restart this summer, following final regulatory approvals and pre-operational safety checks.

In the absence of a significant uptick in demand from fuel buyers, whose requirements continue to be well covered in 2015, there was modest movement in the uranium spot price from the later part of 2014. The spot price has shown some support just below $40 (US).

Looking forward, Canada’s Nuclear Cooperation Agreement with India, and Cameco Inc.’s subsequent supply agreement with India’s Department of Atomic Energy (DAE), represent significant opportunities in the world’s second fastest growing market for nuclear fuel. The sale, into a market that was previously closed to us, provides 7.1 million pounds of uranium concentrate under a long-term contract through 2020 and, we anticipate, marks the beginning of a long and positive relationship with a new customer.

Longer term, strong fundamentals underpin a positive outlook for the industry as 63 reactors are currently under construction, and a net increase of 81 reactors is expected over the next 10 years. This demand fundamental combined with the timing, development and execution of new supply projects and the continued performance of existing supply will determine the pace of market recovery.

Outlook for 2015

Our strategy is to profitably produce at a pace aligned with market signals, while maintaining the ability to respond to conditions as they evolve.

Our outlook for 2015 reflects the expenditures necessary to help us achieve our strategy. Our outlook for uranium revenue, fuel services revenue, consolidated revenue, tax rate and capital expenditures has changed, as explained below. We do not provide an outlook for the items in the table that are marked with a dash.

See 2015 Financial results by segment on page 4 for details.

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Commercial production is achieved when management determines that the mine is able to produce at a consistent or sustainably increasing level. Once we have declared commercial production at Cigar Lake, we will begin depreciating the assets, contributing to an increase in our overall production costs (non-cash), as indicated in our 2015 outlook.

We expect Cigar Lake to produce between 6 million and 8 million packaged pounds in 2015; our share is 3 million to 4 million pounds. As we ramp up production to 18 million pounds (100% basis) by 2018, volumes may not be linear year-to-year, but will vary based on our operational experience. To ensure the most efficient operation of the mine and mill throughout the year, we expect to continually manage ore supply and, therefore, may halt and resume mining several times during a quarter without impacting planned annual production.

AREVA has indicated good progress in the ramp up of the McClean mill, with feed grades exceeding 25% U3O8, and an output well above historical mill production levels. To allow the McClean Lake mill to reach full production of 18 million pounds annually, AREVA now estimates that our share of expenditures related to the mill modifications will be about $80 million in 2015 (previously $60 to $70 million (our share) in 2015), and advises additional expenditures will also be required after 2015. The increase in 2015 expenditures is due to larger quantities of piping, electrical, instrumentation, and related labour, identified upon completion of detailed engineering. AREVA is currently preparing an updated estimate of the cost to complete the mill modifications.

INKAI

Production in the first quarter was 14% lower compared to the same period of 2014, but remains aligned with the current 2015 mine plan. Inkai is on target to produce 5.2 million pounds (100% basis) this year.

The Ministry of Energy of the Republic of Kazakhstan has issued a letter to JV Inkai approving the extension of the period for Block 3 deposit evaluation by three years to July 13, 2018, provided the design document is approved in accordance with the established legislation order before June 13, 2015.

FUEL SERVICES

Fuel services produced 2.6 million kgU in the first quarter, 35% lower than the same period last year, primarily due to the reduced volumes attributable to the early termination of the SFL contract in 2014. We decreased our production target in 2015 to between 9 million and 10 million kgU, so quarterly production is expected to be lower than comparable periods in 2014.

The current collective bargaining agreement for our unionized employees at CFM expires on June 1, 2015. We began preparing for the collective bargaining process during the first quarter.

Qualified persons

The technical and scientific information discussed in this document for our material properties (McArthur River/Key Lake, Inkai and Cigar Lake) was approved by the following individuals who are qualified persons for the purposes of NI 43-101:

MCARTHUR RIVER/KEY LAKE INKAI

• David Bronkhorst, vice-president, mining and  Darryl Clark, general director, JV Inkai technology, Cameco

CIGAR LAKE

• Les Yesnik, general manager, Cigar Lake, Cameco

Caution about forward-looking information

This document includes statements and information about our expectations for the future. When we discuss our strategy, plans, 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 United States securities laws. We refer to them in this document as forward-looking information.

Key things to understand about the forward-looking information in this document:

• It typically includes words and phrases about the future, such as: anticipate, believe, estimate, expect, plan, will, intend, goal, target, forecast, project, strategy and outlook (see examples below).
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• It represents our current views, and can change significantly.
• It is based on a number of material assumptions, including those we have listed on page 10, which may prove to be incorrect.
• Actual results and events may be significantly different from what we currently expect, due to the risks associated with our business. We list a number of these material risks on page 9. We recommend you also review our annual information form and annual and first quarter MD&A, which include 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 IN THIS DOCUMENT

• our expectations about 2015 and future global  our expectations for uranium deliveries in the second uranium supply and demand and number of reactors quarter and for the balance of 2015 including the discussion under the heading Uranium  our future plans and expectations for each of our market update uranium operating properties and fuel services
• our consolidated outlook for the year and the outlook operating sites for our uranium, fuel services and NUKEM segments for 2015

MATERIAL RISKS

• actual sales volumes or market prices for any of our plants, which adversely affect the construction of new plants, the relicensing of existing plants and the products or services are lower than we expect for any reason, including changes in market prices or demand for uranium loss of market share to a competitor  there are changes to government regulations or
• we are adversely affected by changes in foreign policies that adversely affect us, including tax and trade laws and policies currency exchange rates, interest rates or tax rates
• our production costs are higher than planned, or  our uranium suppliers fail to fulfil delivery commitments necessary supplies are not available, or not available on commercially reasonable terms  our McArthur River development, mining or
• our estimates of production, purchases, costs, production plans are delayed or do not succeed for decommissioning or reclamation expenses, or our any reason tax expense estimates, prove to be inaccurate  our Cigar Lake development, mining or production
• we are unable to enforce our legal rights under our plans are delayed or do not succeed, including as a result of any difficulties with the jet boring mining existing agreements, permits or licences
• we are subject to litigation or arbitration that has an method or freezing the deposit to meet production targets, the third jet boring machine does not go into adverse outcome, including lack of success in our disputes with tax authorities operation on schedule in 2015 or operate as expected, or any difficulties with the McClean Lake
• there are defects in, or challenges to, title to our mill modifications or expansion or milling of Cigar properties Lake ore
• our mineral reserve and resource estimates are not
  • we are unable to obtain an extension to the term of

reliable, or we face unexpected or challenging Inkai’s block 3 exploration licence, which expires in geological, hydrological or mining conditions July 2015

• we are affected by environmental, safety and
  • we are affected by natural phenomena, including

regulatory risks, including increased regulatory inclement weather, fire, flood and earthquakes burdens or delays

• our operations are disrupted due to problems with
• we cannot obtain or maintain necessary permits or our own or our customers’ facilities, the unavailability approvals from government authorities of reagents, equipment, operating parts and supplies
• we are affected by political risks critical to production, equipment failure, lack of
• we are affected by terrorism, sabotage, blockades, tailings capacity, labour shortages, labour relations civil unrest, social or political activism, accident or a issues, str kes or lockouts, underground floods, deterioration in political support for, or demand for, cave-ins, ground movements, tailings dam failures, nuclear energy transportation disruptions or accidents, or other
• we are impacted by changes in the regulation or development and operating risks public perception of the safety of nuclear power
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MATERIAL ASSUMPTIONS

• our expectations regarding sales and purchase works as anticipated, and the deposit freezes as volumes and prices for uranium and fuel services planned
  • modification and expansion of the McClean Lake mill
• our expectations regarding the demand for uranium, the construction of new nuclear power plants and the are completed as planned and the mill is able to relicensing of existing nuclear power plants not process Cigar Lake ore as expected being more adversely affected than expected by  the term of Inkai’s block 3 exploration licence does changes in regulation or in the public perception of not expire in July 2015 and is instead extended the safety of nuclear power plants  our ability to continue to supply our products and
• our expected production level and production costs services in the expected quantities and at the
• the assumptions regarding market conditions upon expected times which we have based our capital expenditures  our ability to comply with current and future expectations environmental, safety and other regulatory
• our expectations regarding spot prices and realized requirements, and to obtain and maintain required prices for uranium regulatory approvals our expectations regarding tax rates and payments,  our operations are not significantly disrupted as a

 foreign currency exchange rates and interest rates result of political instability, nationalization, terrorism, sabotage, blockades, civil unrest, breakdown,

• our decommissioning and reclamation expenses
• our mineral reserve and resource estimates, and the natural disasters, governmental or political actions, litigation or arbitration proceedings, the unavailability assumptions upon which they are based, are reliable of reagents, equipment, operating parts and supplies
• the geological, hydrological and other conditions at critical to production, labour shortages, labour our mines relations issues, strikes or lockouts, underground
• our McArthur River development, mining and floods, cave-ins, ground movements, tailings dam production plans succeed failure, lack of tailings capacity, transportation
• our Cigar Lake development, mining and production disruptions or accidents or other development or plans succeed, including the third jet boring machine operating risks goes into operation on schedule in 2015 and operates as expected, the jet boring mining method

Quarterly dividend notice

We announced today that our board of directors approved a quarterly dividend of $0.10 per share on the outstanding common shares of the corporation that is payable on July 15, 2015, to shareholders of record at the close of business on June 30, 2015.

Conference call

We invite you to join our first quarter conference call on Wednesday, April 29th, 2015 at 1:00 p.m. Eastern.

The call will be open to all investors and the media. To join the call, please dial (800) 769-8320 (Canada and US) or (416) 340-8530. An operator will put your call through. A live audio feed of the conference call will be available from a link at cameco.com. See the link on our home page on the day of the call.

A recorded version of the proceedings will be available:

• on our website, cameco.com, shortly after the call
• on post view until midnight, Eastern, May 30, 2015 by calling (800) 408-3053 (Canada and US) or (905) 694- 9451 (Passcode 5846753#)

Additional information

You can find a copy of our first quarter MD&A and interim financial statements on our website at cameco.com, on SEDAR at sedar.com and on EDGAR at sec.gov/edgar.shtml.

Additional information, including our 2014 annual management’s discussion and analysis, annual audited financial statements and annual information form, is available on SEDAR at sedar.com, on EDGAR at sec.gov/edgar.shtml and on our website at cameco.com.

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Profile

We are one of the world’s largest uranium producers, a significant supplier of conversion services and one of two CANDU fuel manufacturers in Canada. Our competitive position is based on our controlling ownership of the world’s largest high-grade reserves and low-cost operations. Our uranium products are used to generate clean electricity in nuclear power plants around the world. We also explore for uranium in the Americas, Australia and Asia. Our shares trade on the Toronto and New York stock exchanges. Our head office is in Saskatoon, Saskatchewan.

As used in this news release, the terms we, us, our, the Company and Cameco mean Cameco Corporation and its subsidiaries; including NUKEM GmbH, unless otherwise indicated.

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Investor inquiries: Rachelle Girard (306) 956-6403

Media inquiries: Gord Struthers (306) 956-6593

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