The first-principle understanding of the processes in the Scrape-Off-Layer (SOL) of a tokamak is crucial for the development of a thermonuclear reactor. 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. We have derived a kinetic model for neutral atoms in the SOL that contains the fundamental elements of neutral dynamics, while remaining relatively simple. The model has been coupled to the drift-reduced Braginskii equations and is implemented in GBS[1], a three-dimensional numerical code developed to simulate SOL turbulence. The code GBS is able to study the self-consistent formation of the plasma profiles as the interplay of the plasma out-flowing from the core, the parallel losses, and turbulent transport. Details of the neutrals model and the interactions with the plasma are given and we present first results indicating a transition into a regime that shows typical signatures of the conduction limited regime, e.g. significant parallel temperature gradients. [1] P. Ricci, et al., Plasma Phys. Control. Fusion 54, 124047 (2012)