This excerpt taken from the PBR 6-K filed Jun 8, 2009.
12.5 Decrease to recoverable value of assets
When applying the reduction test to the recoverable value of assets, the carrying value of an asset or a cash generating unit is compared with its recoverable value. The recoverable value is the higher value between the net sales value of an asset and its value in use. Considering the particularities of the Company's assets, the recoverable value used for valuing the test of reduction to recoverable value is the value in use, except when specifically indicated.
This use value is estimated based on the present value of future cash flows, resulting from the Company's best estimates. The cash flows arising from continuous use of the related assets are adjusted by the specific risks and use the pre-tax discount rate. This rate is derived from the structured post-tax rate in the weighted average cost of capital (WACC). The main assumptions of the cash flows are: prices based on the last strategic plan published, production curves associated with existing products in the Company's portfolio, market operating costs and investments needed for carrying out the projects.
There were no losses through devaluation of assets in 2009.