Thermal-conduction element for improving the manufacture of a package for transporting and/or storing radioactive materials

A method for manufacturing a package (2) holding radiological protection means (22) for transporting and/or storing radioactive materials, the package (2) comprising a lateral body 14) and a plurality of thermal conduction elements (20), each of the thermal conduction elements (20) comprising an internal part (30), an external part (34), and an intermediate part (32), the internal part (30) being in contact with the lateral body (14) of the package (2), the external part (34) forming a portion of an external envelope (24) of said package (2), the intermediate part (32) connecting the internal part (30) to the external part (34), the internal, external, and intermediate parts being integrally formed from copper and one of the alloys thereof, where steel connection areas (36) are positioned at two opposite ends of said external part (34), each of the steel connection areas (36) being welded to a steel connection area positioned on an external part of an adjacent one of the thermal conduction elements, the welded steel connection areas being configured to connect the external part (34) of the thermal conduction element (20) to external parts of adjacent ones of the thermal conduction elements, the method comprising pouring a radiological protection material into one of two of the thermal conduction elements (20a) defining a cavity (50) in which the radiological protection means (22) is to be housed, the pouring being carried out with the one thermal conduction element (20a) being assembled on the package (2).