We work in a chiral invariant quark model, with a condensed vacuum,
characterized by only one parameter. Bound state equations for the nucleon and
Delta are solved in order to obtain an updated value of their radii and masses.
Nucleon-nucleon S-Wave scattering is studied in the RGM framework both for
isospin T=1 and T=0. The phase shifts are calculated and an equivalent local
potential, which is consistent with K-N scattering, is derived. The result is a
reasonable microscopic short range repulsion in the nucleon-nucleon
interaction.Comment: 23 pages in latex revtex, 4 Postscript figure
