The first-principle understanding of the processes in the Scrape-Off-Layer (SOL) of a tokamak is crucial for the developement of a thermonuclear re- actor. Since the plasma temperature in the SOL is rather low, the plasma is typically not fully ionized, and the neutral atoms play an important role in determining the SOL regimes. The description of a simple kinetic model for neutral atoms in the SOL is presented and first results of self-consistent non-linear turbulence simulations with the GBS code [1] are shown. [1] P. Ricci, et al., Plasma Phys. Control. Fusion 54 (2012) 124047