An analytical and separable representation for the two-particle S wave t matrix, for the central Yakawa interactions, has been suggested, which is separable and symmetric in momentum variables p and p'. The sturmian eigenfunctions for the S wave Hulthen potential, which form a complete set, have been used as the expansion bases. For the neutron-proton system, the triplet and the singlet states have been considered, including the soft-core repulsion in the singlet interaction. The resulting t matrix has been used as an input in the Faddeev equation for the neutron-deuteron collision problem, the triton binding energy has been computed and compared with the theoretical calculation of Malfliet and Tjon (1969) as well as the experimental findings.