Patent Number: 
Section: claims

1. A packaging for transporting and/or storing radioactive materials, the packaging delimiting a housing cavity intended to receive a mass of radioactive materials, said housing cavity being at least partly defined by a lateral body, a bottom and a lid mounted removably on the lateral body, the bottom and the lid being spaced apart from each other along a longitudinal axis of the packaging, and the lateral body extending between a first axial end on the lid side and a second axial end on the bottom side,wherein the lateral body has a thickness-change zone defining a transition surface, the lateral body comprising a reduced-thickness part extending from the transition surface towards the first axial end of the lateral body, said reduced-thickness part comprising an internal surface laterally delimiting a hollowed-out zone of the lateral body, also delimited axially by the transition surface,wherein the packaging comprises an insert body extending around the longitudinal axis, arranged removably in said hollowed-out zone, and having an internal surface laterally delimiting a part of the housing cavity,and wherein the internal surfaces are spaced apart from each other so as to have a minimum radial separation greater than 30 mm. 2. The packaging according to claim 1, wherein the insert body:a) is independent of the lateral body and of the lid;b) forms an integral part of the lid, which also comprises a main part for axial closing off of the housing cavity defining an axial-end surface of said housing cavity, the insert body being arranged projecting axially in the direction of the bottom from the axial-end surface; orc) is formed by combining a primary portion,the primary portion forming an integral part of the lid, which also comprises a main part for axial closing off of the housing cavity defining an axial end surface of said housing cavity, the primary portion including firstly a lateral wall forming the internal surface and arranged projecting axially in the direction of the bottom from the axial end surface, and secondly a fixing flange arranged at an axial end of the lateral wall and configured to be in abutment against the transition surface,the secondary portion being independent of the lateral body and of the lid, and arranged radially between the internal surface of the reduced-thickness part of the lateral body, and the assembly formed by the lateral wall of the primary portion and the main part of said lid. 3. The packaging according to claim 2, further comprising means for fixing the lid on the lateral body, the fixing means passing through the insert body and the transition surface of the lateral body. 4. The packaging according to claim 3, wherein, in case c), said fixing means pass through the fixing flange of the primary portion of the insert body. 5. The packaging according to claim 1, wherein a sealing system is gripped axially between the transition surface of the lateral body and an axial end of the insert body. 6. The packaging according to claim 1, wherein the lid is entirely covered laterally by the reduced-thickness part of the lateral body. 7. The packaging according to claim 1, it further comprising an additional lid fixed to the lateral body. 8. The packaging according to claim 1, further comprising an impact-damping cap covering at least part of the lid, as well as the first axial end of the lateral body. 9. The packaging according to claim 1, wherein the internal surface of the insert body laterally delimits an axial section of the housing cavity, the axial section extending over an axial length greater than or equal to 50 mm. 10. The packaging according to claim 1, wherein the transition surface of the lateral body forms an internal shoulder. 11. A parcel comprising the packaging according to claim 1, loaded with a mass of radioactive materials housed in the housing cavity, the mass of radioactive materials being located partly laterally opposite the insert body. 12. A method for discharging a mass of radioactive materials housed in the housing cavity of the packaging according to claim 1, the method comprising the following steps:removing the lid and the insert body, so as to release an annular space of the hollowed-out zone between the internal surface of the reduced-thickness part and an external surface of a top portion of the mass;introducing a handling device into the annular space, in order to connect the handling device to the external surface of the mass; andextracting the mass out of the cavity, by means of the handling device. 13. The parcel according to claim 11, wherein the mass of radioactive materials is in the form of a barrel. 14. The packaging according to claim 1, wherein the insert body is a ring.