[en] Within the frame of Coordinated research program on Safe Core Management with Burnable Absorbers in WWERs organized by IAEA, on of the main tasks was the verification and validation of the available codes for in-core fuel management calculations of lattices with gadolinium burnable absorbers. Besides the comparison with the experimental results a square lattice benchmark with burnable absorber defined by J.J. Arkuszewsky was adopted for comparison of results. In ths paper results obtained by applying different options of the WIMS code and different cross section libraries are presented, compared to those obtained by other methods. It is shown that an appropriate choice of method and adequate library would give satisfactory results. (author)