5. Use of estimates and judgments

The preparation of the consolidated financial statements in conformity with IFRS requires management to make judgments, estimates and assumptions that affect the application of accounting policies and the reported amounts of assets, liabilities, revenues and expenses. Actual results may differ from these estimates.

Estimates and underlying assumptions are reviewed on an ongoing basis. Revisions to accounting estimates are recognized in the period in which the estimates are revised and in any future period affected.

Information about critical judgments in applying the accounting policies that have the most significant effect on the amounts recognized in the consolidated financial statements is discussed below. Further details of the nature of these judgments, estimates and assumptions may be found in the relevant notes to the financial statements.

• A. Recoverability of long-lived and intangible assets

  Cameco assesses the carrying values of property, plant and equipment, and intangible assets annually or more frequently if warranted by a change in circumstances. If it is determined that carrying values of assets or goodwill cannot be recovered, the unrecoverable amounts are charged against current earnings. Recoverability is dependent upon assumptions and judgments regarding future prices, costs of production, sustaining capital requirements and mineral reserves. A material change in assumptions may significantly impact the potential impairment of these assets. In addition, assumptions used in the calculation of recoverable amounts are discount rates, future cash flows and profit margins.

• B. Cash generating units

  In performing impairment assessments of long-lived assets, assets that cannot be assessed individually are grouped together into the smallest group of assets that generates cash inflows that are largely independent of the cash inflows from other assets or groups of assets. Management is required to exercise judgment in identifying these cash generating units.

• C. Provisions for decommissioning and reclamation of assets

  Significant decommissioning and reclamation activities are often not undertaken until near the end of the useful lives of the productive assets. Regulatory requirements and alternatives with respect to these activities are subject to change over time. A significant change to either the estimated costs or mineral reserves may result in a material change in the amount charged to earnings.

• D. Deferred income taxes

  Cameco operates in a number of tax jurisdictions and is, therefore, required to estimate its income taxes in each of these tax jurisdictions in preparing its financial statements. In calculating income taxes, consideration is given to factors such as tax rates in the different jurisdictions, non-deductible expenses, valuation allowances, changes in tax law and management’s expectations of future operating results. Cameco estimates deferred income taxes based on temporary differences between the income and losses reported in its financial statements and its taxable income and losses as determined under the applicable tax laws. The tax effect of these temporary differences is recorded as deferred tax assets or liabilities in the financial statements. The calculation of income taxes requires the use of judgment and estimates. If these judgments and estimates prove to be inaccurate, future earnings may be materially impacted.

• E. Mineral reserves

  Depreciation on property, plant and equipment is primarily calculated using the unit-of-production method. This method allocates the cost of an asset to each period based on current period production as a portion of total lifetime production or a portion of estimated mineral reserves. Estimates of life-of-mine and amounts of mineral reserves are updated annually and are subject to judgment and significant change over time. If actual mineral reserves prove to be significantly different than the estimates, there could be a material impact on the amounts of depreciation charged to earnings.

• F. Pension, other post-retirement and other post-employment benefits

  The carrying value of pensions, other post-retirement and other post-employment benefit obligations is based on actuarial valuations that are sensitive to assumptions concerning discount rates, wage increase rates, and other actuarial assumptions used. Changes in these assumptions could result in a material impact to the financial statements.

• G. Purchase price allocations

  Purchase prices related to business combinations and asset acquisitions are allocated to the underlying acquired assets and liabilities based on their estimated fair value at the time of acquisition. The determination of fair value requires Cameco to make assumptions, estimates and judgments regarding future events. The allocation process is inherently subjective and impacts the amounts assigned to individually identifiable assets and liabilities. As a result, the purchase price allocation impacts Cameco’s reported assets and liabilities, future net earnings due to the impact on future depreciation and amortization expense and impairment tests.

• H. Derivative financial instruments

  Cameco is exposed to risks related to changes in commodity prices, foreign exchange rates and interest rates. Cameco utilizes specific derivative financial instruments to manage these risks. These derivatives are recorded at their fair value. In the determination of the fair value of these instruments, Cameco utilizes independent prices and, when independent prices are not available, internal financial models which are based primarily on observable market data. Management’s judgment is required in the development of these models.