The preliminary results are presented of the experimental determination of threshold reaction rates in experimental samples made of A1, Co, Bi, In, Au et al. Placed both inside and on the surface of extended thick W-Na target irradiated with 0.8 GeV protons. The target consists of 25 alternating discs each 150 mm in diameter: 5 tungsten discs are 20 mm thick, 7 tungsten discs are 40 mm thick, and 13 sodium discs are 40 mm thick. The relative position of discs is matched with the aim of flattening the neutron field along the target surface. The comparison is made of the measured rates with results of their simulation using LAHET and KASKAD-S codes, and MENDL2, MENDL2P, SADKO-2, and ABBN-93 databases. The results are of interest both in terms of integral data collection and demonstration the up-to-the-date predictive power of codes applied in designing hybrid (ADS) systems that use tungsten targets cooled with sodium.