A device for confining nuclear reactor core melt comprising a melt trap and provided with a multilayer vessel containment, a filler, an upper support, and a bottom support comprising a horizontal embedded plate mounted in the concrete of a reactor pit. The plate comprises radial supports, the melt trap comprising radial supports, based on the radial support of the plate. The plate radial supports and the melt trap radial supports are connected with fasteners having holes in the form of hyperbolic surfaces. The radial supports and the clamps have oval holes. The upper support comprises turnbuckles, mounted in pairs on the upper part of the melt trap body so that the longitudinal axis of each radial support of the melt trap bottom support passes in projection at an equispaced distance from the fitting location of the paired turnbuckles and connecting the melt trap body with the reactor pit vertical wall.