Saskatoon, Saskatchewan, Canada, August 21, 2017

Cameco (TSX: CCO; NYSE: CCJ) released an update today to its Sustainable Development Report, providing 2016 data for all 32 Global Reporting Initiative (GRI) indicators and two indicators unique to the corporation.

The update shows how Cameco performed against key indicators that measure social, environmental and economic impacts. The data was gathered using GRI 4.0 sustainability guidelines.

Highlights include:

• A continued focus on local spending with 70% procured from local suppliers.
• Zero significant environmental incidents for the ninth consecutive year.
• Reduction to lost-time incidents (LTI). Two operations achieved more than 10 years without an LTI and five operations achieved at least one year without an LTI.
• In 2016, from a very small operational footprint with the surface area of about five square kilometers, our McArthur River and Cigar Lake operations in northern Saskatchewan produced enough uranium to generate electricity for every Canadian household for four years.
• Continued high levels of public support in locations where we operate.

The 2017 Sustainable Development GRI Index Update can be viewed at cameco.com/sustainable_development/2017/

Profile

Cameco is 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.

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Investor inquiries: Cory Kos (306) 956-8176

Media inquiries: Carey Hyndman (306) 956-6317