  We employ the Keldysh formalism in the quasiclassical approximation to study
transport in a diffusive superconductor. The resulting 4x4 transport equations
describe the flow of charge and energy as well as the corresponding flow of
spin and spin energy. Spin-flip scattering due to magnetic impurities is
included. We find that the spin-flip length is renormalized in the
superconducting case and propose an experimental system to measure the
spin-accumulation in a superconductor.
