This report presents one of the analyses that support the Environmental Radiation Model for Yucca Mountain Nevada (ERMYN), referred to in this report as the biosphere model. Biosphere Model Report (BSC 2004 [DIRS 169460]) describes the details of the conceptual and mathematical biosphere models and the required input parameters. The biosphere model is one of a series of process models supporting the postclosure total system performance assessment (TSPA) for the Yucca Mountain repository.