Packaging for the transport and / or storage of radioactive materials, featuring an improved lid fastening system

Abstract

The invention relates to packaging (1) for the transport and / or storage of radioactive materials, comprising a lid (6) mounted on a side packaging body (2) by means of fastening means comprising at least one fastening device (14), the latter having a support member (30) having a stress surface (32) applying, by contact with a receiving surface (42) of the fastening means provided on the lid, a clamping force of the lid (6) onto the side packaging body (2), the clamping force being oriented along a clamping direction (17). According to the invention, the stress surface (32) comprises a first active zone (ZA1), in contact with a second active zone (ZA2) of the receiving surface (42), as well as a first passive zone (ZP1) opposite and at a distance from a second passive zone (ZP2) of the receiving surface (42), along the clamping direction (17). Figure for the summary: Fig. 2

Description

Title of the invention: PACKAGING FOR THE TRANSPORT AND / OR STORAGE OF MATERIALS RADIOACTIVE, FEATURING AN IMPROVED LID LOCKING SYSTEM technical field

[0001] The present invention relates to the field of packaging for the transport and / or storage of radioactive materials, and to that of packages comprising such packaging, as well as radioactive materials housed in a containment enclosure defined by a packaging body.

[0002] The packaging in question is of the type comprising a removable lid, such as, for example, used for the transport of nuclear fuel assemblies. Within the containment enclosure delimited by the packaging, a storage device can be arranged to hold one or more radioactive items, these being able to be fresh or irradiated nuclear fuel assemblies, containers / casings of vitrified waste or technological waste, containers / casings of shells and end caps, or cases for the transport of powder (PuO2 powder, for example).

[0003] The invention relates more specifically to a system for fixing the lid to the side body of the packaging. PREVIOUS STATE OF THE ART

[0004] A storage and / or transport package for radioactive materials generally comprises, as a sealed outer casing, a package having a body consisting of a side panel, a base, and a removable lid. These parts of the package define a sealed cavity, called a containment chamber, for housing the radioactive materials. A storage device, usually called a storage basket, may also be used to help keep the radioactive materials inside the containment chamber. When such a basket is used, the assembly consisting of the basket and the radioactive materials is called the radioactive contents.

[0005] The safety demonstration of the packaging containing the radioactive material is based in particular on regulatory drop tests. Thus, during an axial drop of nine meters onto a shock-absorbing head cover over the packaging lid, the radioactive material can move axially within the containment structure towards the lid, due to a functional axial clearance between the radioactive material and the lid. of the packaging. As the shock-absorbing head cover collapses, the radioactive contents can then impact this same cover during this fall, known as "axial fall." Very significant forces are thus generated, with a delay, in the fastening means of the removable packaging cover, due to the delayed movement of the radioactive contents within the containment structure. In particular, the lid fastening means, such as screws, are subjected to considerable stress by the deformed cover.

[0006] Maintaining the integrity of the packaging's containment structure during an axial drop may require the implementation of means designed to limit the forces transmitted by the radioactive materials to the lid. This could, for example, involve an internal shock-absorbing system placed within the containment structure, between the lid and the radioactive contents. This system is also known as an internal shock-absorbing system. Numerous solutions for implementing this system have already been proposed in the prior art.

[0007] However, the available space between the lid and the radioactive contents may sometimes prove insufficient to accommodate an internal shock absorber. Even when such a shock absorber can be accommodated, the space allocated to it may prove insufficient for the shock absorber to adequately limit the effects of the radioactive contents impacting the lid, which is moving with a time delay within the containment structure, when the package falls towards the lid.

[0008] Consequently, even with the presence of an internal shock absorber, the delayed impact caused by the radioactive contents on the inner surface of the lid can lead to deformation, resulting in a sort of outward bending of the packaging in the axial direction. This deformation of the lid places significant stress on the fastening screws, which may in turn be at risk of deformation due to the bending moment induced by the lid, thereby causing a risk of leakage between the lid and the side of the packaging.

[0009] Such a risk also exists if the packaging is dropped, causing significant axial forces on the outer face of the lid, for example, forces applied by the external shock-absorbing cover over the lid. Such a situation leads the lid to deform by undergoing a kind of bending, towards the inside of the containment enclosure. Description of the invention

[0010] To address at least partially the drawbacks mentioned above, the invention first relates to packaging for the transport and / or storage of radioactive materials, comprising a packaging body formed by a side packaging body, a packaging base, and a removable lid mounted on an axial end of the side packaging body, using fastening means. comprising at least one fastening device, the latter comprising a support member having a stress surface applying, by contact on a receiving surface of the fastening means provided on the lid, a clamping force of the lid on the lateral body of the packaging, the clamping force being oriented along a clamping direction parallel to a longitudinal central axis of the packaging passing through the lid and the bottom of the packaging body, the receiving surface being traversed by a passage hole through which the fastening device passes, the passage hole being arranged on a peripheral area of ​​the lid.

[0011] According to the invention, the stressing surface comprises a first active zone, in contact with a second active zone of the receiving surface, and a first passive zone opposite and at a distance from a second passive zone of the receiving surface, along the direction of contact. Furthermore, in a view along the direction of contact, the second passive zone extends at least to an outer periphery of the stressing surface of the bearing member, and preferably beyond this outer periphery.

[0012] The invention advantageously allows, locally at the level of the second passive zone of the receiving surface provided on the lid, for local deformation of the lid in the event of a fall, while limiting the mechanical stresses on the fastening means. The risks of permanent deformation of the lid fastening devices, as well as the related risks of leakage between the lid and the side of the packaging, are thus advantageously reduced. The airtightness of the containment enclosure can therefore be maintained without the need to increase the number and / or size of the lid fastening devices.

[0013] The invention preferably provides for the implementation of one or more of the following optional features, taken individually or in combination.

[0014] Preferably, the second active and passive zones are separated from each other by a level break provided on the receiving surface of the cover. Alternatively, the receiving surface of the cover may remain flat. The spacing between the first and second passive zones can then be obtained by making the support member with an assembly consisting of a screw head and a truncated washer bearing against the receiving surface formed on the cover.

[0015] Preferably, the first passive zone and the second passive zone are separated by a gap along the plating direction, with a value greater than or equal to 0.2 mm. In this regard, it is observed that in all the envisaged embodiments, the aforementioned gap / spacing, located axially between the first and second passive zones, may remain empty or possibly be filled by an element comprising a filler material, having a lower crushing stress than that of the cover material(s) and the fastening device.

[0016] Preferably, in the view along the direction of the plating, the first passive zone of the stress surface of the support member has an area equal to at least 5% of the total area of ​​the stress surface of the support member with respect to the receiving surface, and more preferably to at least 10% or 15% of this total area, while preferably remaining less than or equal to 50% of this total area.

[0017] Preferably, the second passive zone of the receiving surface opens into the passage hole through which the fastening device passes.

[0018] Preferably, the second passive zone of the lid receiving surface, its associated fixing device, and the longitudinal central axis of this packaging follow one another in a radial direction of the packaging, preferably being aligned with each other along this same direction.

[0019] According to a preferred embodiment of the invention, the second passive zone of the lid's receiving surface is arranged, in a radial direction of the packaging, between its associated fastening device and the longitudinal central axis of the packaging. This addresses the problem of delayed impact caused by the radioactive content on the inner face of the lid, which could lead to deformation by undergoing a sort of outward bending of the packaging in the axial direction. Alternatively, the radioactive content could consist solely of radioactive materials, without departing from the scope of the invention.

[0020] According to another preferred embodiment of the invention, the second passive zone of the lid's receiving surface is arranged, in a radial direction of the packaging, radially outward relative to its associated fastening device. This addresses the problem of external impact on the lid's outer face, which could cause it to deform by undergoing a kind of inward bending of the packaging in the axial direction. Such stress on the lid could, for example, result from an external shock-absorbing cover when the packaging is dropped onto this cover. Preferably, the second passive zone of the lid's receiving surface extends to a periphery of the lid.

[0021] It is noted that the two preferred embodiments just described can be combined within the same packaging lid, for example by providing diametrically opposed recesses on the receiving surface on either side of the fastening devices, such as screws.

[0022] These two modes could also be combined by providing a package with two separate lids, following one another in the axial direction, the inner lid then being preferably equipped with the principle according to the first mode described above, and the outer lid being preferably equipped with the principle according to the second mode described above.

[0023] According to a preferred embodiment of the invention, the second passive zone of the receiving surface of the lid has the form of a recess of material on the receiving surface of the lid.

[0024] According to another preferred embodiment of the invention, the cover comprises a main cover body, as well as a support device for the fastening device mounted on the cover body, and the second passive area of ​​the receiving surface is provided on the cover body, and the second active area of ​​the receiving surface is provided on the support device, which is preferably a removable wear part.

[0025] Preferably, the fastening device is a screw, or an assembly consisting of a screw and a washer, and the bearing member is the screw head, or the washer, or an assembly consisting of the screw head and the washer. As an alternative to screws, tie rods or studs fitted with nuts, or equivalent means, may be used.

[0026] Preferably, the fastening means comprise a plurality of fastening devices spaced circumferentially from each other, at least some of them, or even all of them, each implementing the principle of the invention.

[0027] Preferably, the packaging includes an internal shock absorber, intended to protect the lid and arranged inside a containment enclosure for radioactive materials, the containment enclosure being defined by the packaging body.

[0028] Finally, the invention also relates to a package comprising such packaging, as well as radioactive materials arranged in the packaging.

[0029] Other advantages and features of the invention will appear in the detailed, non-limiting description below. Brief description of the drawings

[0030] This description will be made with reference to the attached drawings, among which;

[0031] [Fig.1] represents a schematic axial cross-sectional view of a package according to the invention;

[0032] [Fig.2] represents a partial axial cross-sectional view of the packaging belonging to the package shown in the previous figure, and showing one of the devices for fixing the packaging lid to the packaging body, the packaging being in the form of a preferred embodiment of the invention, this view also corresponding to a section taken along line II-II of [Fig.3];

[0033] [Fig.3] represents a view along the direction of plating of the cover onto the body lateral packaging, showing the cooperation between different areas of a stress surface provided on a support member of the fixing device shown in the previous figure, and a receiving surface provided on the lid;

[0034] [Fig.4] is a view similar to that of [Fig.3], showing another mode of preferred realization of the invention;

[0035] [Fig.5] is a view similar to that of [Fig.3], showing another preferred embodiment of the invention;

[0036] [Fig.6] is a view similar to that of [Fig.2], showing another preferred embodiment of the invention;

[0037] [Fig.7] is a view similar to that of [Fig.2], showing another preferred embodiment of the invention;

[0038] [Fig.8] is a view similar to that of [Fig.2], showing another preferred embodiment of the invention;

[0039] [Fig.9] represents a partial perspective view of the packaging belonging to the parcel shown in the previous figure, the packaging being in the form of another preferred embodiment of the invention;

[0040] [Fig. 10] represents a view similar to that of [Fig.9], showing another preferred embodiment of the invention;

[0041] [Fig. 11] is a view similar to that of [Fig.2], showing another preferred embodiment of the invention;

[0042] [Fig. 12] is a view similar to that of [Fig.2], showing yet another preferred embodiment of the invention.

[0043] DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS

[0044] With reference first to [Fig.1], a package 100 for the storage and / or transport of radioactive materials 12 is shown. It comprises first of all a package 1, having a packaging body formed by a side body 2, a bottom 4 and a removable lid 6 closing an opening of the package opposite the bottom 4. The package has a central longitudinal axis 8 around which the side body 2 extends, this axis 8 passing through the lid 6 and the bottom 4 respectively arranged at the axial ends of the side body 2 of the package. As schematically illustrated in [Fig.1], the base 4 can be made in one piece with the side body of the packaging 2. The lid 6 is attached to the opposite axial end of the side body 2, corresponding to the upper axial end in the vertical storage position of the packaging, shown in [Fig.1].The attachment of this cover 6 is achieved using fastening means, comprising a plurality of fastening devices 14 spaced circumferentially from one another around the periphery of the cover, so as to form an annular row of devices 14. In the cross-sectional view of [Fig. 1], only two fastening devices 14 are shown, schematically only. Their design and arrangement are specific to the invention, and various preferred embodiments will be described with reference to the following figures. Preferably, several of these fastening devices 14 have the design specific to the invention, and even more preferably, all of them.

[0045] As will be detailed below, each fastening device 14 is preferably a screw, or an assembly consisting of a screw and a washer, this fastening device being arranged on a peripheral area of ​​the cover. Furthermore, such a fastening device 14 includes a bearing member on the cover 6, this bearing member being the washer, the screw head, or an assembly consisting of the screw head and the washer, when the latter is truncated.

[0046] The side body 2, the lid 6, and the base 4 define a containment enclosure 10, used to house the radioactive materials 12. The lid 6 and the base 4 thus form the two opposing axial sealing elements of the containment enclosure 10, which is sealed by means of one or more sealing gaskets 11, axially clamped between the lid 6 and the corresponding axial end of the side body of the packaging 2. Preferably, the sealing gasket 11 is located radially inwards relative to the annular ring of fastening devices 14. In this regard, in [Fig. 1], a radial direction 15 of the packaging, relative to its longitudinal central axis 8, and the axial / longitudinal direction 17 of this packaging, parallel to the axis 8, are shown.It is noted that the axial direction 17 of the packaging also corresponds to a direction of the lid 6 being pressed against the lateral body of the packaging 2, this pressing being carried out by the fastening devices 14. When such a basket is used, the assembly consisting of the basket and the radioactive materials is called radioactive content.

[0047] The radioactive materials 12, represented schematically only, are preferentially held laterally in the containment enclosure 10 by a storage basket.

[0048] Radioactive materials may consist of fresh or irradiated nuclear fuel assemblies. Instead of nuclear fuel assemblies, radioactive materials, as defined in the invention, could alternatively be vitrified waste containers / casings, shell and end cap containers / casings, or powder transport casings.

[0049] As shown in dotted lines on [Fig.1], at opposite ends of the package considered along axis 8, the package 1 can be equipped with external shock-absorbing covers 20, protecting respectively the removable cover 6 and the base 4 of the package.

[0050] The packaging 1 is also equipped with an internal shock absorber 22, shown schematically only in [Fig. 1], and which can be made in any form known in the prior art. This internal shock absorber 22 is housed in the containment enclosure 12, axially between an inner face 24 of the lid 6, and an axial end surface 26 of the radioactive content. Preferably, the internal shock absorber 22 is fixed to the inner face 24 of the lid 6, for example by means of screwed elements. or by welding. It could alternatively be fixed to the axial end surface 26 of the radioactive content, or freely arranged between this radioactive content and the cover.

[0051] Thus, the internal damping system 22 can be arranged in several ways between the radioactive content 12 and its associated axial sealing element, formed by the removable cover 6.

[0052] In a preferred embodiment shown in Figures 2 and 3, one of the fastening devices is shown comprising the screw 14 and a support washer 63, having a surface area greater than or equal to that of the screw head 30, and completely covering the latter, according to the facing direction 17. In a similar embodiment, but not shown, this support member could be directly the screw head 30.

[0053] The surface under the thrust washer, forming the aforementioned bearing member, is a load-bearing surface 32, here annular in shape and centered on an axis 34 of the screw. When the screw 14 is tightened into a tapped hole 36 in the side packaging body, the load-bearing surface 32 of the thrust washer applies, by contact with a receiving surface 42 for the fastening means provided on the cover 6, a clamping force of the cover 6 against the upper axial end of the side packaging body 2. Consequently, the receiving surface 42 provided on the cover is axially aligned with the load-bearing surface 32 provided on the thrust washer 63, while preferably extending locally beyond this surface 32 in the radial direction 15, as will be described below.

[0054] The receiving surface 42 is traversed by a through hole 44 through the cover 6. This hole 44 is traversed by a shaft of the screw 14, and is therefore also arranged on a peripheral area 46 of the cover 6, always with reference to the axis 8.

[0055] One of the features of the invention lies in the fact that the loading surface 32 comprises a first active zone ZA1, in contact with a second active zone ZA2 of the receiving surface 42. These two active zones of surfaces 32 and 42 enable the application of the clamping force on the cover. Furthermore, the loading surface 32 comprises a first passive zone ZP1 opposite and at a distance from a second passive zone ZP2 of the receiving surface 42, along the clamping direction 17.

[0056] In [Fig. 3], the first active zone ZA1 is denoted by dots “.”, while the first passive zone ZP1 is denoted by colons “:”. The boundary between these two adjacent zones ZA1 and ZP1 is also denoted by colons. Similarly, the second active zone ZA2 is denoted by dashes “-”, while the second passive zone ZP2 is denoted by colons “=”.

[0057] Furthermore, for greater clarity, the second passive zone ZP2 is represented hatched, with a different hatching pattern than that of the second active zone ZA2. These last two zones ZA2, ZP2 are also adjacent, with their boundary marked by double dashes.

[0058] In this preferred embodiment, the loading surface 32, which is thus formed by the first two zones ZA1, ZP1, has a ring shape centered on the screw axis 34. The boundary between these two zones ZA1, ZP1 can take the form of a straight line passing through the ring, without passing through its central hollow area. In this regard, it is noted that, still in the view of [Fig. 3], taken along the plating direction 17, the first passive zone ZP1 of the loading surface 32 has an area equal to at least 5% of the total area of ​​this loading surface. It is specified that this total area of ​​the loading surface 32, preferably planar, corresponds to the sum of the area of ​​the first passive zone ZP1 and the area of ​​the first active zone ZA1.More preferably, the area of ​​the first passive zone ZP1 corresponds to at least 10% or 15% of this total area, while preferably remaining less than or equal to 50% of this total area, and even more preferably less than or equal to 40%.

[0059] The receiving surface 42, which is therefore made up of the two second zones ZA2, ZP2, has a more complex shape than that of the stressing surface 32 of the support washer 63. Indeed, while the second active zone ZA2 has a shape identical to the first active zone ZA1, that is to say a truncated ring shape at its outer periphery, the second passive zone ZP2, hatched on [Fig.3], differs from the first passive zone ZP1. This passive zone ZP2 corresponds to the part removed from the truncated ring, i.e. the equivalent of the surface of the passive zone ZP1, to which is added a second part which preferably extends radially beyond the outer periphery of the stress surface 32 of the support washer 63, in the direction of the axis 8. Indeed, in this preferred embodiment, the second passive zone ZP2 is arranged, in the radial direction 15, between the shank of the screw 14 and the axis 8. As has been schematically shown in [Fig.[3], the shape of the second passive zone ZP2 can thus correspond to that of a disk truncated at its periphery, with the truncation line being identical to the line defining the boundary between the first active zone ZA1 and the first passive zone ZP1.

[0060] Still within the framework of this preferred embodiment of the invention, the second passive zone ZP2 is in the form of the bottom of a material recess 50, formed on the receiving surface 42 of the cover, forming an integral part of its external face. In other words, the support washer 63 is partially aligned axially with the recess 50 on the cover, so that only a part of the A support washer 63 is used to transmit the clamping force to the cover 6. At this recess 50, an axial clearance 52 is observed in the clamping direction 17 between the first passive zone ZP1 and the second passive zone ZP2. This clearance 52, with a value greater than or equal to 0.2 mm, corresponds to the depth of the recess 50. Furthermore, it is noted that the presence of this recess marks a level break 54 between the second active and passive zones ZA2, ZP2, which are thus separated from each other at one side of the recess forming this level break, on the receiving surface 42 of the cover 6.

[0061] In the event of a fall of the packaging, it is the two passive zones ZP1, ZP2 of the surfaces 32, 42 which allow the lid 6 to deform outwards following an impact of the radioactive content, drastically limiting the bending moment induced in the barrels of the fixing screws 14. Indeed, during such a deformation of the lid, the support washer 63 and, consequently, the end of the screw head 30 which are located radially inwards in the direction of the axis 8, are not or only slightly stressed by the deformed part of the lid, since the recess 50 avoids / limits the contact with this end of the head of the support washer. The associated risks of leakage at the seal 11, between the lid 6 and the side body of the packaging 2, in the event of the packaging being dropped and the lid being deformed outwards, are advantageously reduced.

[0062] Figures 4 and 5 represent other preferred embodiments, similar to the previous one.

[0063] In the embodiment of [Fig. 4], the loading surfaces 32 and receiving surfaces 42 have the same general shapes as in the previous embodiment. Only the boundary between the two zones ZA1, ZP1, and the boundary between the two zones ZA2, ZP2 change. Indeed, these two boundaries, which are always superimposed in the view along the plating direction 17, are closer to the screw axis 34 since the second passive zone ZP2 opens into the through hole 44.

[0064] In the preferred embodiment of [Fig.5], the second passive zone ZP2 also opens into the passage hole 44. But its shape differs in that it corresponds not to a truncated disk eccentric to the screw axis 34, but to an angular sector of a ring centered or substantially centered on this same screw axis 34.

[0065] In the preferred embodiment of [Fig. 6], the cover 6 comprises a main cover body 6a and a screw support device 6b mounted on the main cover body 6a. This mounting is achieved, for example, by storing the support device 6b between the screw head 30 and the main cover body 6a in a recess 60 on the outer face of the periphery of this body. The support device 6b may be a ring or a spacer, centered on the screw axis 34, and through which the screw shank passes. It is preferably a wear part, easily replaceable. The support device 6b is therefore partially embedded in the main cover body 6a, while projecting upwards from the outer face of the main body 6a. The axial projection distance of the support device 6b, which also corresponds to the clearance 52, is thus established between the second passive zone ZP2 provided on the main body 6a, and the second active zone ZA2 provided at the upper end of the support device 6b. Furthermore, the level break 54 between the second active and passive zones ZA2, ZP2 corresponds to the outer lateral surface of the support device 6b.

[0066] In the preferred embodiment of [Fig.7], the fastening device comprises the screw 14 and a truncated support washer 62, so that the support member is constituted by the assembly formed by the screw head 30 and the truncated washer 62. In this embodiment, the washer 62 does not cover the entire screw head 30 in the facing direction 17, but a part of this screw head 30 is thus found opposite and at a distance from the receiving surface 42, which can be provided to be flat on the cover 6. It is this part of the screw head 30 that forms the first passive zone ZP1 of the stress surface 32, while the rest of this surface 32, namely the first active zone ZA1, is formed by the surface of the truncated washer 62 bearing against the cover. As previously stated, the receiving surface 42, which includes the two zones ZA2, ZP2, can be flat, and fit within the plane of the external face of the cover 6.The game 52 is then dictated by the thickness of the truncated washer 62.

[0067] By way of example, it is noted that in a similar embodiment, but not shown, the truncated washer 62 can be replaced by a conventional washer, with an outside diameter strictly less than that of the screw head 30.

[0068] The preferred embodiment of [Fig. 8] is similar to that of Figures 2 and 3. The only change lies in filling the recess 50 with an element 64 comprising a filling material that has a lower crushing strength than the material(s) of the cover 6 and the screw 14. For example, this could be a sealing element comprising polyurethane foam, or any other material known to perform the filling function while limiting the transmission of forces towards the bearing member of the fastening device. In this respect, this filling principle is applicable to all embodiments of the invention, in particular to those using a bearing member formed by any washer 63 interposed between the screw head 30 and the cover 6, as shown in [Fig. 9].As an alternative to filling, a thin sheet of metal welded around its entire perimeter can be used to cover the recess 50, and facilitate its decontamination.

[0069] The preferred embodiment of [Fig. 9] contrasts with the previous ones in that the second passive zone ZP2 of the receiving surface 42 is arranged, in the radial direction 15, outwards relative to the fixing screw 14. Here, the screw head 30 is received in a counterbore 66 in the outer face of the cover 6, and the bottom of the counterbore 66 forms the two second zones ZA2, ZP2, preferably coplanar. This embodiment has been shown with a bearing element formed by the combination of the screw head 30 and a truncated washer 62, but any other embodiment remains conceivable. The counterbore 66 is also preferably open radially outwards, so that the second passive zone ZP2 of the receiving surface 42 extends to a periphery of the cover 6.

[0070] The radially outward orientation of the second passive zone ZP2 addresses the problem of external impact on the outer face of the lid, which could cause it to deform by undergoing a kind of inward bending towards the packaging, in the axial direction. Such stress on the lid 6 could, for example, originate from the external shock-absorbing cover (not shown) when the packaging is dropped onto this cover.

[0071] The preferred embodiment of [Fig. 10] is based on the same principle, with a second passive zone ZP2 opening radially to the outside. Here, the receiving surface 42 is provided on a hollowed annular portion 70 at the periphery of the cover 6.

[0072] The preferred embodiment of [Fig. 1 1] is very similar to that of [Fig. 2], with the screw head 30 arranged in a counterbore 66 of the cover. Other arrangements among those described previously can, however, be considered with respect to the screw 14, the particularity of this embodiment lying here in the design of the cover 6. Indeed, the latter comprises, firstly, a sealing plug 6c, which delimits the containment chamber 10. The cover 6 also includes a fixing flange 6d, partially axially covering the plug 6c. It is with a peripheral part of this flange 6d that the screw 14 cooperates, in order to fix the flange 6d on the side body of packaging 2. The tightening of the flange with the screws 14 causes the cap 6c of the lid to be pressed against the side body of packaging 2, and the seal 11 disposed between the cap 6c and the side body of the packaging to be crushed.

[0073] Finally, the preferred embodiment of [Fig. 12] provides for packaging with two lids 6. The two lids are arranged in succession along the plating direction 17, so as to conventionally form an inner or primary lid on the side of the containment enclosure 10, and an outer or secondary lid on the opposite side. The two lids 6 are fixed by means of fastening devices 14 of any design described above. However, preferably, the primary lid is more subject to the risk of outward deformation due to the stresses caused by the radioactive contents in the event of In the fall, the arrangements retained are preferentially those described with reference to figures 2 to 8. In these modes, the second passive zone ZP2 of the receiving surface of the cover is effectively arranged between the screw 14 and the axis 8, which allows the aforementioned deformation of the cover, without risking the break in sealing at the level of the joint 11.

[0074] Conversely, since the secondary cover is more subject to the risk of inward deformation due to the forces caused by the external shock-absorbing cover in the event of a fall, the arrangements retained are preferably those described with reference to Figures 9 and 10. In these modes, the second passive zone ZP2 of the receiving surface of the cover is effectively arranged radially outwards with respect to the screw 14, which allows the aforementioned deformation of the cover, without risking a break in the seal at the joint 11.

[0075] Of course, various modifications can be made by a person skilled in the art to the invention just described, solely by way of non-limiting examples, the scope of which is defined by the appended claims. In particular, the characteristics of the different embodiments presented above are interchangeable and combinable.

Claims

Demands

1. Packaging (1) for the transport and / or storage of radioactive materials (12), comprising a packaging body formed by a side packaging body (2), a packaging base (4), and a removable lid (6) mounted on an axial end of the side packaging body, by means of fastening means comprising at least one fastening device (14), the latter having a support member (30, 62) having a bearing surface (32) applying, by contact with a receiving surface (42) of the fastening means provided on the lid, a clamping force of the lid (6) onto the side packaging body (2), the clamping force being oriented along a clamping direction (17) parallel to a longitudinal central axis (8) of the packaging passing through the lid (6) and the base (4) of the packaging body, the receiving surface (42) being traversed by a through hole (44) through which passes the fastening device fixing (14),the passage hole being arranged on a peripheral area (46) of the cover, characterized in that the stress surface (32) comprises a first active area (ZA1), in contact with a second active area (ZA2) of the receiving surface (42), as well as a first passive area (ZP1) opposite and at a distance from a second passive area (ZP2) of the receiving surface (42), according to the facing direction (17), and in that in a view according to the facing direction (17), the second passive area (ZP2) extends at least to an external periphery of the stress surface (32) of the support member (30, 62), and preferably beyond this external periphery.

2. Packaging according to claim 1, characterized in that the second active and passive zones (ZA2, ZP2) are separated from each other by a level break (54) provided on the receiving surface (42) of the lid (6).

3. Packaging according to claim 1 or 2, characterized in that the first passive zone (ZP1) and the second passive zone (ZP2) are separated by a gap (52) along the plating direction (17), of a value greater than or equal to 0.2 mm.

4. Packaging according to any one of the preceding claims, characterized in that in the view along the plating direction (17), the first passive zone (ZP1) of the stress surface (32) of the support member (30, 62) has an area equal to at least 5% of the total area of ​​the stress surface (32) of the support member with respect to the receiving surface (42), and more preferably to at least 10% or 15% of this total area, while preferably remaining less than or equal to 50% of this total area.

5. Packaging according to any one of the preceding claims, characterized in that the second passive zone (ZP2) of the receiving surface (42) opens into the passage hole (44) through which the fastening device (14) passes.

6. Packaging according to any one of the preceding claims, characterized in that the second passive zone (ZP2) of the receiving surface (42) of the lid (6), its associated fixing device (14), and the longitudinal central axis (8) of this packaging follow one another in a radial direction (15) of the packaging.

7. Packaging according to claim 6, characterized in that the second passive zone (ZP2) of the receiving surface (42) of the lid (6) is arranged, in the radial direction (15) of the packaging, between its associated fastening device (14), and the longitudinal central axis (8) of this packaging.

8. Packaging according to claim 6, characterized in that the second passive zone (ZP2) of the receiving surface (42) of the lid (6) is arranged, in the radial direction (15) of the packaging, radially outwards relative to its associated fastening device (14).

9. Packaging according to claim 8, characterized in that the second passive zone (ZP2) of the receiving surface (42) of the lid (6) extends to a periphery of the lid.

10. Packaging according to any one of the preceding claims, characterized in that the second passive zone (ZP2) of the receiving surface (42) of the lid (6) has the form of a material recess (50) on the receiving surface (42) of the lid.

11. Packaging according to any one of claims 1 to 9, characterized in that the lid (6) comprises a main lid body (6a), as well as a support device (6b) for a fastening device mounted on the lid body (6a), and in that the second passive zone (ZP2) of the receiving surface (42) is provided on the cover body (6a), and the second active zone (ZA2) of the receiving surface (42) is provided on the support device (6b), which is preferably a removable wear part.

12. Packaging according to any one of the preceding claims, characterized in that the fastening device (14) is a screw, or an assembly formed by a screw (14) and a washer (62, 63), and in that the bearing member is the screw head (30), or the washer (63), or an assembly formed by the screw head (30) and the washer (62).

13. Packaging according to any one of the preceding claims, characterized in that the fastening means comprise a plurality of fastening devices (14) spaced circumferentially from each other.

14. Packaging according to any one of the preceding claims, characterized in that it comprises an internal shock absorber (22), intended to protect the lid (6) and arranged inside a containment enclosure (10) for radioactive materials (12), the containment enclosure (10) being defined by the packaging body.

15. Package (100) comprising a package (1) according to any one of the preceding claims, and radioactive material (12) arranged in the package.

Images