Abstract: Stackable long-term storage container especially for radioactive waste comprises especially convoluted lid and bottom pieces to facilitate stacking. The lid is convoluted providing an annular projection which serves to allow grabbing of the lid and, together therewith, the drum. The floor has a rim which extends axially away from the floor and then is bent over upward toward the drum with drainage openings provided at the bottom edge. A resilient jacket is disposed around the bottom edge and surrounds the rim to prevent direct contact between the drums and scratching during stacking. A fiberglass reinforced plastic insert inside the drum protects the inner wall from damage. The special shape of the drum prevents causes for corrosion under all operating conditions of the drum, especially during very rough handling of the drum during filling, transport and storage.