Packaging for transporting and / or storing radioactive material

Abstract

The invention relates to a package (1) for transporting and / or storing radioactive material (3), the package comprising a cavity (12) for accommodating the radioactive material, and a radiation protection device (14) comprising radioactive protection elements (16) arranged in an annular space (18). According to the invention, locking means (32) are provided in association with at least two successive radioactive protection elements (16) along a given direction of the annular space, the given direction being a longitudinal direction (8) and a circumferential direction (28), the locking means being designed to limit / prevent the distance of the two radioactive protection elements (16) relative to each other along the given direction.

Description

TECHNICAL FIELD

[0001] The present invention relates to the field of packages for the transport and / or storage of radioactive materials, such as nuclear fuel assemblies or radioactive waste.

[0002] More specifically, the present invention relates to a package comprising a radiation protection device formed by a plurality of individual elements, such as cast resin radiation protection elements. BACKGROUND

[0003] It is known from the prior art to provide a package equipped with a radiation protection device arranged around a cavity for containing radioactive materials. The function of this device is to prevent gamma radiation and / or neutron absorption in order to meet the regulatory radiation standards around the package when it is loaded with radioactive materials.

[0004] To this end, a solution consists in inserting radiation protection elements into an annular space centered on the longitudinal central axis of the package. These elements generally take the form of blocks which can be inserted into the annular space thanks to the presence of cold joints. This cold joint also enables the thermal expansion of the radiation protection material, thus limiting the thermal mechanical stresses of these blocks on the parts of the package which delimit the annular space.

[0005] During a transport operation using this type of package, the radiation protection elements can move and slide with respect to each other in the annular space. The cumulative movement between these elements can locally cause the appearance of a gap between two adjacent elements with unacceptable values in terms of radiation leakage.

[0006] There is therefore a need to optimize the design of existing packages to remedy the aforementioned drawbacks. SUMMARY

[0007] To meet this need, the present invention relates to a package for the transport and / or storage of radioactive materials, said package comprising a cavity for containing radioactive materials, and a radiation protection device arranged around the containment cavity in an annular space centered on the longitudinal central axis of the package, the radiation protection device comprising radiation protection elements arranged in the annular space.

[0008] According to the invention, a locking member associated with at least two consecutive radiation protection elements in a given direction of the annular space, said given direction being the longitudinal direction and the circumferential direction of said space, is provided in the space, said locking member being designed to limit / prevent the distance of the two radiation protection elements with respect to each other in the given direction, the locking member cooperating with or being integrated in a first of said two radiation protection elements and cooperating with a hollow formed on a second of these two radiation protection elements.

[0009] The application advantageously makes it possible to limit the distance between the radiation protection elements in the annular space of the package, thereby significantly reducing the risk of radiation leakage between these radiation protection elements.

[0010] Furthermore, the application has at least any one of the optional features listed below, used independently or in combination.

[0011] According to a preferred embodiment of the application, the locking member is integral with the first radiation protection element.

[0012] Preferably, the locking member is an elongated member, preferably having a cross-section in the shape of a truncated disc, a square or a trapezoid. Other shapes can obviously be chosen without departing from the scope of the application.

[0013] Preferably, the elongated locking member extends orthogonally or substantially orthogonally to said given direction.

[0014] According to another preferred embodiment of the application, the locking member is a separate component from the first and second radiation protection elements, and said locking member also cooperates with a hollow formed on the first radiation protection element.

[0015] Preferably, the locking member is a component whose dimensions are smaller than those of the first and second radiation protection elements, and said locking member is preferably made of a different material.

[0016] Preferably, the locking member is a pin, a wedge or a clamp.

[0017] Preferably, the locking member extends only over a portion of the radial thickness of the annular space.

[0018] According to a preferred embodiment of the application, the first and second radiation protection elements are directly adjacent in said given direction in a single annular row of radiation protection elements.

[0019] According to another preferred embodiment of the application, the first and second radiation protection elements belong respectively to two concentric annular rows of radiation protection elements, such that the first and second radiation protection elements are circumferentially offset relative to each other while partially overlapping in the radial direction of the annular space.

[0020] Preferably, the locking member is located at the level of the radial overlap area of the first and second radiation protection elements.

[0021] Preferably, the annular space is delimited by an inner collar and an outer shell. In this respect, it should be noted that the inner collar can form the entire lateral body of the package or a partial lateral body, or indeed can be provided in addition to the lateral package body which delimits the cavity for accommodating the radioactive material.

[0022] Preferably, the annular space has no thermal conductor connecting the inner collar to the outer shell.

[0023] Preferably, the radiation protection elements are neutron protection elements, preferably cast resin blocks.

[0024] Preferably, at least one radiation protection element, and preferably a plurality of these elements, or even each of these radiation protection elements, of the radiation protection device is associated with two locking members designed to limit / prevent the distance of the two radiation protection elements in a given direction with respect to each of the two radiation protection elements located on the two sides of the two locking members in the same given direction. This arrangement limits the risk of accumulation of gaps between different radiation protection elements, both for a configuration with a single annular row and for a configuration with two concentric annular rows of radiation protection elements.

[0025] Further advantages and features of the application will emerge from the non-limiting detailed description hereinafter. BRIEF DESCRIPTION OF DRAWINGS

[0026] The description will be made with reference to the drawings, in which:

[0027] Figure 1 a schematic longitudinal axial sectional view of a package for transporting and / or storing radioactive material according to a preferred embodiment of the application is shown;

[0028] Figure 2 a sectional view taken along the line II-II of Figure 1 ;

[0029] Figure 3 a perspective view of a radiation protection element used in the package shown in Figure 1 and Figure 2 ;

[0030] Figure 4 a longitudinal axial sectional view of a portion of a package according to another preferred embodiment of the application is shown;

[0031] Figure 5 a view of a package presented according to an alternative, similar to Figure 4 ;

[0032] Figure 6 is a view of a package presented according to an alternative, similar toFigure 4 a view of a package according to another preferred embodiment of the application;

[0033] Figure 7 is a schematic view showing another preferred embodiment of a radiation protection device equipped on a package;

[0034] Figure 8 is a view similar to Figure 2 a view of a package according to another preferred embodiment of the application, wherein the radiation protection device has two concentric annular rows of radiation protection elements;

[0035] Figure 9 is a schematic view showing different forms of a locking member equipped on a radiation protection device;

[0036] Figure 10 is a partially sectioned view showing another preferred embodiment of a radiation protection device having two concentric annular rows of radiation protection elements; and

[0037] Figure 11 shows a view of a package according to another preferred embodiment of the application, similar to Figure 8 a view of a package according to another preferred embodiment of the application, similar to DETAILED DESCRIPTION

[0038] Reference is first made to Figure 1 , Figure 1 a package 1 for the transport and / or storage of radioactive material, such as nuclear fuel assemblies 3 or radioactive waste (in Figure 1 only partially and schematically shown).

[0039] The package 1 is shown in a vertical storage position, in which the longitudinal central axis 2 of the package 1 is oriented vertically. The package is placed on a package base 4 opposite a removable lid 6 along a height direction 8 parallel to the longitudinal axis 2. The height direction 8 thus corresponds to the longitudinal direction of the package.

[0040] Between the base 4 and the lid 6, the package 1 comprises a lateral body 10 extending around the axis 2 and internally delimiting a cavity 12 for accommodating the radioactive material 3. The cavity 12 can form an accommodation enclosure intended to receive the radioactive material, for example arranged in a storage tray also located in the accommodation enclosure. Alternatively, the accommodation enclosure is entirely defined by a shell (also called "can") placed in the above-mentioned cavity 12. The enclosure is axially closed at the top by the lid 6 and at the bottom by the base 4, which can be integral with the lateral body 10 of the package. Indeed, these elements 4, 6 and 10 form the body of the package, in particular intended to ensure the mechanical strength of the package in the event of a fall, in order to maintain the sealing of the accommodation enclosure.

[0041] The package 1 is also equipped at its periphery with a radiation protection device, here a neutron protection device 14. This device is formed using a plurality of neutron protection elements 16, each of which extends along the entire or partial length of the lateral body 10 of the package along the direction 8. Alternatively, the device 14 can be formed using blocks 16 stacked along the direction 8. Each radiation protection element 16 takes the form of a preformed block, preferably made of cast resin. This resin can contain boron or any other neutron-absorbing element, i.e. a plurality of neutron-absorbing elements. The term “neutron-absorbing element” refers to an element having an effective cross section greater than 100 barns for thermal neutrons.

[0042] In the following, the neutron protection elements 16 will be referred to as “protection blocks 16” or “blocks 16”. The protection blocks are arranged in an annular space 18 which is centred on the axis 2 and is delimited by an inner collar 20 and an outer shell 22. In the illustrated preferred embodiment, the inner collar 20 is an added component around the lateral body 10 of the package, but alternatively the inner delimitation of the annular space 18 can be performed directly by the outer surface of the lateral body 10. The outer shell 22 itself forms the lateral perimeter of the package 1. Figure 1 In the illustrated preferred embodiment, the inner collar 20 is an added component around the lateral body 10 of the package, but alternatively the inner delimitation of the annular space 18 can be performed directly by the outer surface of the lateral body 10. The outer shell 22 itself forms the lateral perimeter of the package 1.

[0043] The elements 4, 6, 10 of the package body can be metallic, for example made of steel or cast iron. The inner collar 20 and the outer shell 22 can also be metallic, for example made of steel. In the annular space 18, also referred to as the inner collar space, no thermal conductor is preferably provided in addition to the protection blocks 16. This particular case corresponds to a package intended for the transport of radioactive materials emitting only low thermal power or no thermal power. The term “thermal conductor” denotes a conductor usually used in packages, usually arranged alternately with the neutron protection blocks, and connecting the inner collar 20 to the outer shell 22. However, it is conceivable for the thermal conductor to take the form of an annular disc. The blocks 16 would then alternate with the heat-conducting disc in the direction 8. Reference is now made to Figure 2 and Figure 3 , showing the shape of the successive blocks 16 along the circumferential direction 28 of the annular space 18 with respect to the axis 2. In this preferred embodiment, all the blocks 16 form a single annular row of blocks centred on the axis 2, the thickness of which is slightly less than the total thickness “E1” of the annular space 18 along the radial direction 30 of this space.

[0044] Here, preferably, each block 16 of the annular row is identical, i.e. each block has the same shape and the same dimensions. Typically, each block 16 is made in one piece from two substantially parallelepiped portions 16a, 16b that are offset relative to each other along the circumferential direction 28 as well as along the radial direction 30. Indeed, the first portion 16a forms a radially outer portion of the block 16, which is connected to the second portion 16b forming a radially inner portion of the same block and is circumferentially offset.

[0045] Since the blocks 16 are continuous along the circumferential direction 28, the first portion 16a of a first block at least partially covers in the radial direction the second portion 16b of a second block 16 directly adjacent in the circumferential direction 28, in the same way, the second portion 16b of the first block is at least partially covered in the radial direction by the first portion 16a of a third block 16 directly adjacent in the circumferential direction 28 but opposite the second block.

[0046] One of the features of the application is to use a device for limiting / preventing the circumferential distance between adjacent blocks 16, so as to avoid that the accumulation of such distances leads to an unacceptable degree of neutron leakage between two directly adjacent blocks 16. To this end, preferably, the blocks 16 of a single annular row, preferably all or almost all of these blocks, are respectively associated with two locking members 32 intended to limit / prevent the circumferential distance of the two blocks 16 respectively relative to each of the two blocks located on either side of these two locking members in the circumferential direction 28.

[0047] It should be noted that in all the preferred embodiments, as can be seen from the entire description, the annular space 18 of the package is delimited radially outwards by an outer shell 22 centred on the axis 2, in which the radiation protection elements 16 and the locking members 32 are arranged.

[0048] Hereinafter, only the arrangement of the locking members 32 with the two blocks 16 of the latter will be described in detail, in which this arrangement limits / prevents the distance to be the same at the height of each of the locking members.

[0049] In this preferred embodiment, each locking member 32 located in the annular space 18 is integral with the first portion 16a of the first block 16 associated therewith. Alternatively, each locking member located in the annular space can be integrated in the second portion 16b without departing from the scope of the application.

[0050] In the case where the locking member 32 is integrated in the first portion 16a of the first block 16, this member 32 takes the form of a radially inwardly projecting protrusion extending in an elongated manner along the longitudinal direction 8, i.e. locally or substantially orthogonally to the circumferential direction 28. Thus, the elongated protrusion 32 extends continuously along the entire length of the associated first block 16, or only along a portion of the entire length of the associated first block 16. In the cross-section shown in Figure 2 the protrusion 32 has a truncated disc shape (e.g. a half-disc), or any other shape (such as a square, a rectangle, a trapezium, etc.).

[0051] The protrusion 32 is housed in a hollow 34 having a complementary shape, which is radially outwardly open and is provided on the second portion 16b of the second block 16 directly adjacent to the first block along the circumferential direction 28. Thanks to the cooperation between the protrusion 32 and the hollow 34, the first and second protective blocks 16 cannot be spaced apart from each other along the circumferential direction 28, or only by a limited amplitude by exploiting the circumferential clearance between these two components 32, 34.

[0052] Finally, it should be noted that the cooperation between the protrusion 32 and the hollow 34 of the different blocks 16 is obtained by the insertion of each block into the annular space 18, by the relative sliding of each protrusion 32 in its associated hollow 34 in the form of a slot.

[0053] Moreover, it is found that the above-described preferred embodiment can be transposed in the case of a series of protective blocks 16 in the annular space 18 along the longitudinal direction 8. This case is illustrated in Figure 4 where the locking members 32 are still in the form of radial protrusions, but here extend in an elongated manner along the circumferential direction 28, similar to the hollows 34 in which these protrusions 32 are inserted.

[0054] By way of illustration, during the manufacture of the package, the locking members 32 of the blocks 16 are inserted into the hollows 34 of the blocks directly adjacent in the longitudinal direction 8, before the respective portions of these two blocks 16 are inserted longitudinally into the annular space 18.

[0055] Figure 5 An alternative to the solution proposed in Figure 4 is illustrated. Here, the locking members 32 form the longitudinal end of the first portion 16a of the blocks 16, which still project radially inwardly. Moreover, the hollows 34 of the protective blocks 16 are formed between the junction between the two portions 16a, 16b of the protective block 16 on the one hand and another protrusion 16' on the other hand, which projects radially outwardly and forms the opposite longitudinal end of the block 16 provided on the second portion 16b.

[0056] Again, in the context of a single row of protection elements 16, it is possible to provide for the mutual retention of these blocks 16 to be performed by locking members that are not integrated in the blocks, but are separate from the blocks and cooperate therewith. In Figure 6 a preferred embodiment of this aspect is shown in which the blocks 16 still adopt the same overall shape with two portions 16a, 16b. The locking members 32 take the form of clamps or similar elements, each of which couples two directly adjacent blocks 16 in the longitudinal direction 8 to limit / prevent the relative distance of these two directly adjacent blocks in this same direction in the annular space 18.

[0057] Thus, each clamp 32 has two tabs that are respectively housed in two hollows 34 of a first protection block 16 and a second protection block 16 connected by it. The central body of each clamp 32 extends along the circumferential direction 28 and the tabs of each clamp, arranged at the ends of this body, radially protrude to be housed in the respective hollows 34 of the blocks 16.

[0058] As Figure 6 shown in

[0059] This clamp system can also be used in a similar way to limit / prevent the relative distance between the blocks 16 in the circumferential direction 28 without departing from the scope of the invention.

[0060] Reference is now made to Figure 7 , showing another preferred embodiment for coupling the blocks 16 in the longitudinal direction 8 with locking members 32 separate from the blocks. This involves a wedge-type or similar design with two opposite longitudinal portions 32', each of which is shaped like a dovetail, respectively housed in a complementary-shaped hollow 34 formed on the longitudinal end facing the two blocks 16 in question. In this embodiment, each block 16 has a curvature in the circumferential direction 28 to follow the overall shape of the annular space 18 in which it is located.

[0061] In all embodiments that envisage the locking members 32 separate from the protection blocks 16 to which they are connected, these members 32 respectively form components of smaller size than the blocks 16. In addition, each locking member 32 extends only along a portion of the radial thickness E1 of the annular space 18, for example along 5% to 30% of this thickness.

[0062] Preferably, the locking members 32 are made of a material different from that of the blocks 16, for example a metal material.

[0063] All the principles associated with the preferred embodiments described above apply to the following design, in which the protection device 14 comprises two or more concentric annular rows of protection blocks 16 centered on the axis 2.

[0064] In Figure 8 The preferred embodiment of the application comprises two concentric rows 36a, 36b arranged in the annular space 18, each of these rows being formed by a series of protection blocks 16 along the circumferential direction 28. Each block 16 extends along the direction 8 along all or part of the length of the lateral body 10 of the package. Each block has a simple shape, for example a substantially parallelepiped, optionally with a curvature along the circumferential direction 28 to follow the overall shape of the annular space 18 in which it is located. Here, each block 16 of each of the two rows 36a, 36b is preferably made in one piece, comprising a first portion 16a and a second portion 16b located in the circumferential extension of the first portion 16a. An angular positioning bias is adopted between the blocks 16 of the first row 36a located radially outward and the blocks 16 of the second row 36b located radially inward, so that the interfaces between the blocks 16 of the first row 36a are not radially aligned with the interfaces between the blocks of the second row 36b. This arrangement makes it possible to limit the leakage of neutrons that occurs through these interfaces, compared to the arrangement of interleaved rows of blocks 16 forming the two rows 36a, 36b.

[0065] In this configuration, each block 16 of the first row 36a has a first portion 16a covered by the second portion 16b of one of the blocks of the second row 36b, in the same way, the second portion 16b of the block 16 of the first row 36a is covered by the first portion 16a of the directly adjacent block in the second row 36b. The same applies to each block 16 of the second row 36b, in which the first portion 16a is covered by the second portion 16b of one of the blocks of the first row 36a, and in which the second portion 16b is covered by the first portion 16a of the directly adjacent block in the first row 36a. Thus, a circumferential bias can be observed between two blocks 16 belonging respectively to the two rows 36a, 36b and partially overlapping each other.

[0066] In other words, the first portion 16a of a first block 16 of the second row 36b is covered in the radial direction 30 by the second portion 16b of a second block 16 of the first row 36a, and the second portion 16b of this first block is still covered in the radial direction 30 by the first portion 16a of a third block 16 of the first row 36a, the second and third blocks 16 being directly adjacent along the circumferential direction 28 in the first row 36a. Similarly, the first portion 16a of a first block 16 of the first row 36a is covered in the radial direction 30 by the second portion 16b of a second block 16 of the second row 36b, and the second portion 16b of this first block is still covered in the radial direction 30 by the first portion 16a of a third block 16 of the second row 36b, the second and third blocks 16 being directly adjacent along the circumferential direction 28 in the second row 36b. Moreover, it should be noted that when two blocks 16 partially cover each other along the radial direction 30, even if these same blocks 16 do not belong to the same annular row, these same blocks 16 are considered to be consecutive along the circumferential direction 28.

[0067] In this preferred embodiment of the application, each protective block 16 of the second row 36b comprises two locking members 32 spaced from each other along the circumferential direction, a first locking member 32 being located in the first portion 16a and a second locking member 32 being located in the second portion 16b. Moreover, each protective block 16 of the first row 36a comprises two hollows 34 spaced from each other along the circumferential direction, a first hollow being located in the first portion 16a and a second hollow being located in the second portion 16b. Thus, each protective block 16 of the second row 36b has a first locking member 32 inserted into the second hollow 34 of a block 16 of the first row 16a, while the second locking member 32 is inserted into the first hollow 34 of a directly adjacent block 16 of the first row 16a. Thus, in this embodiment, the locking members 32 are located at the level of the radial overlap zone of two blocks 16, which locking members contribute to fix the two blocks relative to each other, thereby contributing to limit / prevent the relative gap between these two same blocks along the circumferential direction 28.

[0068] Naturally, this design can be reversed by providing protruding members 32 on the blocks of the first row 36a and hollows 34 on the blocks of the second row 36b, without departing from the scope of the application.

[0069] In the preferred embodiment of the application, Figure 8 the radially protruding locking members 32 are identical or similar to the locking members described with reference to Figure 2 , i.e. in particular have a cross-section in the form of a half-disc. However, all other features described with reference to Figure 2 , such as the elongated nature of the members 32 along the longitudinal direction 8, are also applicable.

[0070] According to the preferred embodiment of the application, Figure 9In another possible embodiment, briefly illustrated in Fig. 3, the radially protruding locking members 32 can have a trapezoidal shape, just like the hollows 34 cooperating with these locking members.

[0071] According to the embodiment illustrated in Fig. 1, the radially protruding locking members 32 have a substantially rectangular shape, just like the hollows 34 cooperating with these locking members. Figure 10 According to another preferred embodiment illustrated in Fig. 2, the two concentric annular rows 36a, 36b are formed by blocks 16 each having a substantially U-shaped cross section. The second row 36b comprises U-shaped blocks 16 wherein the two opposite arms protrude radially outwards, while the first row 36a comprises U-shaped blocks 16 wherein the two opposite arms protrude radially inwards.

[0072] The two arms of each block 16 of the second row 36b form two locking members 32 of this block, respectively, while the space 40 defined between the two arms of each block 16 of the first row 36a forms two adjacent hollows 34 which are joined to each other in the circumferential direction and are intended to receive the two arms / members 32 belonging to two directly adjacent blocks 16 of the second row 36b, respectively. In this case, the two adjacent locking members 32 belonging to two separate blocks 16 have a shape which is complementary to the shape of the space 40 in which these two members are inserted.

[0073] This configuration with U-shaped protection blocks 16 is also applicable in the case where, in the annular space 18, these protection blocks 16 are continuous along the longitudinal direction 8, the arms of the U-shape of the second row 36b then limiting / preventing the longitudinal distance between the blocks 16 by cooperating with the spaces 40 defined between the arms of the U-shape of the first row 36a.

[0074] Obviously, thanks to the preferred shape features between the U-shaped blocks of the two rows 36a, 36b, it is alternatively possible to consider that the two arms of each block 16 of the first row 36a form two locking members 32 of this block, respectively, while the space defined between the two arms of each block 16 of the second row 36b would form two adjacent hollows 34 which are joined to each other in the circumferential direction and are intended to receive the two arms / members 32 belonging to two directly adjacent blocks 16 of the first row 36a, respectively.

[0075] Moreover, again in the case of a design with double annular rows of blocks 16, it is also possible to provide a configuration with locking members 32 separate from and not integral with these blocks 16. For example, in the case of a design with double annular rows of blocks 16, it is possible to provide a configuration with locking members 32 separate from and not integral with these blocks 16, as illustrated in Fig. 4. Figure 11In this case, the protruding members are replaced by pins 32 oriented radially, with the two opposite ends housed in two hollows 34 belonging respectively to two blocks 16, one block 16 belonging to the first row 36a and the other block 16 belonging to the second row 36b. For the two given blocks 16, a plurality of pins 32 can be provided, spaced apart from each other along the longitudinal direction 8. Alternatively, one or more pins 32 can be replaced by a wedge extending along the same longitudinal direction 8, with the two opposite edges of the wedge housed in the two hollows 34, each in the form of a longitudinal groove.

[0076] It is clear that a person skilled in the art can make various modifications to the application described above, only by way of non-limiting example, and in the light of the range defined by the claims below. In particular, the different preferred embodiments described above can be combined, and the features of these preferred embodiments remain interchangeable.

Claims

1. Package (1) for the transport and / or storage of radioactive material (3), the package comprising a cavity (12) for accommodating the radioactive material, and a radiation protection device (14) arranged in an annular space (18) centered on a longitudinal center axis (2) of the package, the radiation protection device (14) comprising radiation protection elements (16) arranged in the annular space (18), characterized in that a locking member (32) associated with at least two consecutive radiation protection elements (16) in a given direction of the annular space, the given direction being a longitudinal direction (8) and a circumferential direction (28) of the annular space (18), the locking member being designed to limit / prevent the distance of the two radiation protection elements (16) relative to each other in the given direction, the locking member (32) cooperating with or being integrated in a first of the two radiation protection elements, and cooperating with a hollow (34) formed on a second of the two radiation protection elements.

2. The package of claim 1, wherein, The locking member (32) is integral with the first radiation protection element.

3. The package of claim 2, wherein, The locking member (32) is an elongated member, the locking member having a cross-section in the shape of a truncated disc, a square or a trapezoid.

4. The package of claim 3, wherein, The elongated locking member (32) extends in a manner orthogonal or substantially orthogonal to the given direction.

5. The package of claim 1, wherein, The locking member (32) is a separate part from the first and second radiation protection elements, and wherein the locking member (32) also cooperates with a hollow (34) formed on the first radiation protection element.

6. The package of claim 5, wherein, The locking member (32) is a part whose dimensions are smaller than the dimensions of the first and second radiation protection elements, and the locking member is made of a different material.

7. The package of claim 5, wherein, The locking member (32) is a pin, a wedge or a clamp.

8. The package of claim 5, wherein, The locking member (32) extends only along a portion of the radial thickness (El) of the annular space (18).

9. The package of claim 1, wherein, The first and second radiation protection elements are directly adjacent in the given direction in a single annular row of radiation protection elements (16).

10. The package of claim 1, wherein, The first and second radiation protection elements belong to two concentric annular rows (36a, 36b) of radiation protection elements (16) respectively, such that the first and second radiation protection elements are circumferentially offset relative to each other while partially overlapping in the radial direction (30) of the annular space (18).

11. The package of claim 10, wherein, The locking member (32) is located at the level of the radial overlap area of the first and second radiation protection elements.

12. The package of claim 1, wherein, The annular space (18) is delimited by an inner collar (20) and an outer housing (22).

13. The package of claim 12, wherein, The annular space (18) has no thermal conductor connecting the inner collar (20) to the outer housing (22).

14. The package of claim 1, wherein The radiation protection elements (16) are neutron protection elements.

15. The package of claim 1, wherein, At least one radiation protection element (16) of the radiation protection device (14) is associated with two locking members (32) designed to limit / prevent the distance of two radiation protection elements (16) located on both sides of the two locking members in the given direction, respectively, with respect to each of the two radiation protection elements in the given direction.

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