Abstract: A method of producing a concrete container for storage of radioactive waste includes the steps of providing a double-walled mold with an inner and an outer wall, the mold being open at the top and having an interior for receiving the radioactive waste. The space between the inner and the outer walls is filled with fibers. Subsequently, a concrete mixture is filled into the space between the inner and the outer walls to a level below the uppermost layer of fibers. The interior is closed off by a cover plate. After placing more fibers onto the cover plate a concrete mixture is poured onto the fibers until they are completely covered. Alternatively, it is possible to place a cover plate onto the inner wall for closing of the interior after insertion of the radioactive waste, fill the space between the inner and the outer walls with fibers, and place additional fibers onto the cover plate.