  We consider a problem of nuclear waste contamination. It takes into account
the thermal effects. The temperature and the contaminant's concentration
fulfill convection-diffusion-reaction equations. The velocity and the pressure
in the flow satisfy the Darcy equation, with a viscosity depending on both
concentration and temperature. The equations are nonlinear and strongly
coupled. Using both finite volume and nonconforming finite element methods, we
introduce a scheme adapted to this problem. We prove the stability and
convergence of this scheme and give some error estimates.
