Our mineral reserves and resources are the foundation of our company and fundamental to our success.

Mineral Reserves

Mineral reserves are the economically mineable part of measured or indicated mineral resources demonstrated by at least a preliminary feasibility study. They fall into two categories:

• proven reserves: the economically mineable part of a measured resource for which a preliminary feasibility study demonstrates that economic extraction is justified.
• probable reserves: the economically mineable part of a measured and/or indicated resource for which a preliminary feasibility study demonstrates that economic extraction can be justified.

As at December 31, 2012 (100% basis — only the second last column shows our share)

Proven and probable (tonnes in thousands; pounds in millions)
		Proven			Probable
Property	Mining method	Tonnes	Grade %U3O8	Content (lbs U3O8)	Tonnes	Grade %U3O8	Content (lbs U3O8)
McArthur River	underground	365.8	24.18	195.0	684.8	12.18	183.9
Cigar Lake	underground	233.6	22.31	114.9	303.5	15.22	101.8
Rabbit Lake	underground	87.2	0.62	1.2	1,380.7	0.71	21.6
Key Lake	open pit	61.9	0.52	0.7
Inkai	ISR	2,774.3	0.08	5.1	61,031.1	0.07	88.7
Gas Hills–Peach	ISR				999.2	0.11	2.4
North Butte– Brown Ranch	ISR				1,839.3	0.08	3.3
Smith Ranch– Highland	ISR	1,373.2	0.10	3.0	1,781.5	0.08	3.2
Crow Butte	ISR	1,117.6	0.12	2.9	17.3	0.18	0.1
Total		6,013.6	–	322.8	68,037.4	–	405.0

Reserves continued (tonnes in thousands; pounds in millions)
	Total mineral reserves
Property	Tonnes	Grade %U3O8	Content (lbs U3O8)	Cameco's share of content (lbs U3O8)	Estimated metallurgical recovery (%)
McArthur River	1050.6	16.36	378.9	264.5	98.7
Cigar Lake	537.1	18.30	216.7	108.4	98.5
Rabbit Lake	1,467.9	0.70	22.8	22.8	96.7
Key Lake	61.9	0.52	0.7	0.6	98.7
Inkai	63,805.4	0.07	93.8	53.9	85.0
Gas Hills–Peach	999.2	0.11	2.4	2.4	72.0
North Butte/ Brown Ranch	1,839.3	0.08	3.3	3.3	80.0
Smith Ranch– Highland	3,154.7	0.09	6.2	6.2	80.0
Crow Butte	1,134.9	0.12	3.0	3.0	85.0
Total	74,051.0	–	727.8	465.1
Notes Estimates in the above table: use an average uranium price of $61 (US)/lb U3O8 are based on an average exchange rate of $1 US=$1.00 Cdn, except Cigar Lake, which is based on an average exchange rate of $1.00 US=$1.10 Cdn Totals may not add up due to rounding. Except for the possible Inkai permitting issue referred to below, we do not expect these mineral reserve estimates to be materially affected by metallurgical, environmental, permitting, legal, taxation, socio-economic, political, marketing or other relevant issues. Metallurgical recovery We report mineral reserves as the quantity of contained ore supporting our mining plans, and include 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 quantity of contained metal (content) by the planned metallurgical recovery percentage. Our share of uranium in the table above is before accounting for estimated metallurgical recovery. Estimates for Inkai Our 2013 and future annual production targets for Inkai assume, and we expect that Inkai will obtain the necessary government permits and approvals to produce at an annual rate of 5.2 million pounds (100% basis), including an amendment to the resource use contract. There is no certainty Inkai will receive these permits or approvals. If Inkai does not, or if the permits and approvals are delayed, Inkai may be unable to achieve its 2013 and future annual production targets and we may have to re-categorize some of Inkai's mineral reserves as resources.

Mineral Resources

Mineral resources do not have demonstrated economic viability, but have reasonable prospects for economic extraction. They fall into three categories: measured, indicated and inferred. Our reported mineral resources are exclusive of mineral reserves.

• Measured and indicated mineral resources can be estimated with a level of confidence sufficient to allow the appropriate application of technical and economic parameters to support evaluation of the economic viability of the deposit.
• measured resources: we can confirm geological and grade continuity to support production planning.
• indicated resources: we can reasonably assume geological and grade continuity to support mine planning.
• inferred mineral resources are estimated using limited information. We do not have enough confidence to evaluate their economic viability in a meaningful way. You should not assume that all or any part of an inferred mineral resource will be upgraded to an indicated or measured mineral resource as a result of continued exploration.

Our share of uranium in the mineral resource tables below is based on our respective ownership interests, except for Inkai which is based on our interest in potential production (57.5%), which differs from our ownership interest (60%). Mineral resources that are not mineral reserves have no demonstrated economic viability.

Important information for US investors

While the terms measured, indicated and inferred mineral resources are recognized and required by Canadian securities regulatory authorities, the US Securities and Exchange Commission (SEC) does not recognize them. Under US standards, mineralization may not be classified as a 'reserve' unless it has been determined at the time of reporting that the mineralization could be economically and legally produced or extracted. US investors should not assume that:

• any or all of a measured or indicated mineral resource will ever be converted into proven or probable mineral reserves.
• any or all of an inferred mineral resource exists or is economically or legally mineable, or will ever be upgraded to a higher category. Under Canadian securities regulations, estimates of inferred resources may not form the basis of feasibility or prefeasibility studies. Inferred resources have a great amount of uncertainty as to their existence and economic and legal feasibility.

The requirements of Canadian securities regulators for identification of 'reserves' are also not the same as those of the SEC, and mineral reserves reported by us in accordance with Canadian requirements may not qualify as reserves under SEC standards.

Other information concerning descriptions of 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 US domestic mining companies, including Industry Guide 7.

Mineral resources

As at December 31, 2012 (100% basis — only the second last column shows our share)

Measured and indicated (tonnes in thousands; pounds in millions)
		Measured			Indicated
Property	Mining method	Tonnes	Grade %U3O8	Content (lbs U3O8)	Tonnes	Grade %U3O8	Content (lbs U3O8)
McArthur River	underground	81.7	4.83	8.7	15.5	9.97	3.4
Cigar Lake	underground	18.9	1.68	0.7	25.5	2.71	1.5
Kintyre	open pit				4,315.4	0.58	55.2
Rabbit Lake	underground				485.6	0.6	6.4
Dawn Lake	open pit, underground				347.0	1.69	12.9
Millennium	underground				742.7	4.16	68.2
Phoenix	underground				152.4	15.60	52.3
Tamarack	underground				183.8	4.42	17.9
Inkai	ISR				28,992.7	0.08	48.6
Gas Hills–Peach	ISR	1,964.2	0.08	3.4	6,857.9	0.12	18.8
North Butte– Brown Ranch	ISR				7,248.9	0.08	12.3
Smith Ranch– Highland	ISR	2,324.5	0.10	5.2	14,618.1	0.06	17.8
Crow Butte	ISR				2,595.1	0.21	12.2
Ruby Ranch	ISR				2,215.3	0.08	4.1
Ruth	ISR				1,080.5	0.09	2.1
Shirley Basin	ISR	89.2	0.16	0.3	1,638.2	0.11	4.1
Total		4,478.5	–	18.3	71,514.6	–	337.8

Resources continued (tonnes in thousands; pounds in millions)
	Total measured and indicated
Property	Tonnes	Grade %U3O8	Content (lbs U3O8)	Cameco's share of content (lbs U3O8)
McArthur River	97.2	5.65	12.1	8.5
Cigar Lake	44.4	2.27	2.2	1.1
Kintyre	4,315.4	0.58	55.2	38.7
Rabbit Lake	485.6	0.60	6.4	6.4
Dawn Lake	347.0	1.69	12.9	7.4
Millennium	742.7	4.16	68.2	47.7
Phoenix	152.4	15.60	52.3	15.7
Tamarack	183.8	4.42	17.9	10.3
Inkai	28,992.7	0.08	48.6	28.0
Gas Hills–Peach	8,822.1	0.11	22.2	22.2
North Butte/ Brown Ranch	7,248.9	0.08	12.3	12.3
Smith Ranch– Highland	16,942.6	0.06	23.0	23.0
Crow Butte	2,595.1	0.21	12.2	12.2
Ruby Ranch	2,215.3	0.08	4.1	4.1
Ruth	1,080.5	0.09	2.1	2.1
Shirley Basin	1,727.4	0.12	4.4	4.4
Total	75,993.1	–	356.1	244.1

Inferred (tonnes in thousands; pounds in millions)
Property	Mining method	Tonnes	Grade %U3O8	Content (lbs U3O8)	Cameco's share of content (lbs U3O8)
McArthur River	underground	329.4	7.78	56.5	39.5
Cigar Lake	underground	373.4	12.01	98.9	49.5
Kintyre	open pit	950.2	0.46	9.6	6.7
Rabbit Lake	underground	375.0	1.24	10.3	10.3
Millennium	underground	191.5	5.29	22.3	15.6
Phoenix	underground	11.6	29.80	7.6	2.3
Tamarack	underground	45.6	1.02	1.0	0.6
Inkai	ISR	254,606.1	0.05	255.0	146.6
Gas Hills–Peach	ISR	861.5	0.07	1.3	1.3
North Butte– Brown Ranch	ISR	594.3	0.06	0.8	0.8
Smith Ranch– Highland	ISR	6,404.0	0.05	6.6	6.6
Crow Butte	ISR	2,114.6	0.12	5.4	5.4
Ruby Ranch	ISR	56.2	0.14	0.2	0.2
Ruth	ISR	210.9	0.08	0.4	0.4
Shirley Basin	ISR	508.0	0.10	1.1	1.1
Total		267,632.3	–	477.0	286.9
Notes ISR — in situ recovery Mineral resources do not include amounts that have been identified as mineral reserves. Mineral resources do not have demonstrated economic viability. Totals may not add up due to rounding.