EP2140460A1

EP2140460A1 - Container for transporting and/or storing nuclear material, said container including a mobile heat-conducting structure

Info

Publication number: EP2140460A1
Application number: EP08736305A
Authority: EP
Inventors: Lilian Viallon; Roger Lahille; Laurent Stachetti
Original assignee: TN International SA
Current assignee: TN International SA
Priority date: 2007-04-18
Filing date: 2008-04-17
Publication date: 2010-01-06
Anticipated expiration: 2028-04-17
Also published as: ES2528208T3; JP5781304B2; US9200839B2; EP2140460B1; JP2010525309A; US20100119029A1; WO2008135359A1; CN101681688A; FR2915307B1; FR2915307A1; CN101681688B

Abstract

The invention relates to a storage device (2) for transporting and/or storing nuclear material, including a main structure (5) defining at least one housing intended to house the nuclear material. According to the invention, the container also includes a mobile heat-conducting structure (8) forming at least part of an outer side surface (7) of the storage device, said mobile structure (8) including at least one mobile heat-conducting element (10) mounted on the main structure (5) such that it can be reversibly moved from a retracted position to a deployed positioned by separating same from the structure (5).

Description

CONTAINER FOR TRANSPORTING AND / OR STORING MATERIALS

NUCLEAR, THE CONTAINER COMPRISING A STRUCTURE

THERMAL CONDUCTION MOBILE

DESCRIPTION

TECHNICAL AREA

The present invention relates generally to the field of transport and / or storage of nuclear materials, such as assemblies of nuclear fuel, and in particular fresh fuel, for example of the Mox type.

Nevertheless, the invention could also apply to the field of transport and / or storage of irradiated fuel assemblies, without departing from the scope of the invention.

It could also find an application in the field of transport and / or storage of other types of nuclear material, namely more particularly nuclear material generating a significant thermal power, such as vitrified waste also called "glasses" and corresponding to fission products.

STATE OF THE PRIOR ART

Conventionally, for the transport and / or storage of nuclear fuel assemblies, storage devices are used, also called "basket" or "rack" storage. These storage devices, usually of cylindrical shape and of substantially circular section, have a plurality of adjacent housings each adapted to receive a nuclear fuel assembly. In addition, the storage device is intended to be housed in the cavity of a package to form together with it a container for the transport and / or storage of nuclear fuel assembly, wherein the nuclear material is perfectly confined.

It should be noted that the storage device is generally removable. In other words, it is designed to make it easy and easy to load into the cavity of the package. An operating clearance is thus provided between the cavity of the package and the storage device to allow these loading / unloading operations of the basket.

It is usually desired to obtain a satisfactory thermal conduction between the basket and the packaging, in order to evacuate to the outside of the container, the significant heat generated by the fuel assemblies.

This heat evacuation is partly sought in order to meet the maximum temperature criterion for fuel assemblies. Indeed, in case of exceeding this temperature, the integrity of the fuel rods that constitute the assemblies could be weakened because of the potential degradation of the mechanical characteristics of the sheaths of these rods.

In addition, it should be noted that the mechanical strength of the basket must be compatible with the regulatory safety requirements for the transport / storage of nuclear material, in particular with regard to so-called free fall tests. However, the mechanical characteristics of the materials used for the manufacture of the basket can degrade significantly depending on the temperature, particularly when these materials are aluminum or one of its alloys. Heat evacuation between the basket and the packaging is therefore also sought so as to ensure satisfactory mechanical strength of the basket.

For economic reasons, the inner side surface defining the cavity of the package is made with wide manufacturing tolerances. One of the disadvantages resulting from the use of wide manufacturing tolerances lies in the need to substantially increase the clearance usually provided to make it possible and easy to load a removable basket into the cavity of the package, as mentioned previously. . The observed play then fulfills a role of thermal insulation that goes against the desired overall goal of thermal conduction between the basket and the package, and thus makes it difficult to evacuate the heat released by the nuclear fuel assemblies.

STATEMENT OF THE INVENTION

The object of the invention is therefore to overcome the disadvantages mentioned above, relating to the embodiments of the prior art.

To do this, the invention firstly relates to a storage device for transport and / or storing nuclear material, such as nuclear fuel assemblies, preferably fresh, comprising a main structure defining at least one housing for containing said nuclear material, the device also comprising a movable thermal conduction structure forming at least one part of a lateral outer surface of said storage device, said mobile thermal conduction structure comprising at least one movable thermal conduction member mounted on said main structure so as to be reversibly movable from a retracted position to a deployed position by moving away from said main structure.

The storage device or storage basket according to the invention therefore presents in an original manner a deployable character allowing it to substantially increase the contact surfaces with the inner lateral surface of the package, delimiting the cavity in which is located the basket. The heat transfer between the basket and the packaging is thus satisfactorily provided, without requiring the use of narrow and expensive manufacturing tolerances for the realization of the inner lateral surface delimiting the cavity. Indeed, even if the use of wide manufacturing tolerances leads to consider greater play between the package and the basket that usually provided to allow the loading of the latter, once it housed inside of the cavity, the thermal conduction structure can then to be deployed in order to obtain the desired contact surface between the basket and the cavity of the package, which limits or even completely eliminates the adverse effects previously discussed relating to the presence of the initial high clearance forming thermal insulation.

The heat removal function provided by the thermal conduction structure in the deployed position makes it possible to meet the maximum temperature criterion allowed for the fuel assemblies, or for all the other types of nuclear material intended to be stored / transported. Consequently, with the configuration according to the invention, the risks of degradation of the protective sheaths of the assemblies and their risk of mechanical weakening are advantageously reduced to nothing.

Finally, it is stated that the reduction of the overall temperature within the storage basket, permitted by the thermal conduction structure, advantageously generates an increase in the service life of this basket, particularly when it is made of aluminum or in one of its alloys.

In the latter case, the temperature reduction also contributes to justify more easily the mechanical behavior of the basket, especially during the free fall tests.

If, as is apparent from the foregoing, the heat conduction structure is preferably deployed until contact is made with the cavity of the package, it is also possible to envisage a smaller deployment, not leading to contact. above, without departing from the scope of the invention. Indeed, a simple deployment of the thermal conduction structure has the advantageous consequence of reducing the clearance initially provided between the basket and the packaging, so that the heat transfer between these two elements is substantially improved.

Thanks to the reversible nature of the displacement of the movable member, the latter can be later returned to its retracted position, in particular to facilitate the extraction of the basket out of the package.

Preferably, in at least one longitudinal half-section of the storage device passing through a longitudinal axis thereof and passing through the mobile thermal conduction structure, the sum of the lengths of each movable element of the mobile structure traversed, according to the longitudinal axis of the storage device, represents at least 20% of a total length of said storage device along its longitudinal axis. Naturally, it is stated that the higher the value of the percentage indicated above, the more the heat transfer provided by the moving elements of thermal conduction is satisfactory.

Preferably, at least one movable element is articulated on said main structure, along an axis of articulation parallel to a longitudinal axis of said storage device. This design is perfectly suited to obtaining a longitudinal linear contact between the movable element and the packaging cavity. In this respect, it is preferable to ensure that each of the elements movable structure is mounted articulated on said main structure, along an axis of articulation parallel to the longitudinal axis of the storage device.

Preferably, the hinge axis passes through a peripheral portion of said main structure.

In addition, the lateral outer surface of at least one movable element, and preferably of each of these elements, takes the form of an angular portion of a cylindrical surface of longitudinal axis parallel to a longitudinal axis of said storage device said angular portion being less than or equal to 180 °. Thus, when they occupy their retracted position, the movable elements can participate in the formation of a lateral outer surface of the storage device of substantially cylindrical shape, and preferably of circular section.

Preferably, at least one movable element, and preferably each of these elements, is articulated on said main structure at a longitudinal edge of this element.

Still preferentially, around a given longitudinal portion of said main structure, said mobile structure has a plurality of movable thermal conduction elements, distributed peripherally. In such a case, it can be provided that in the retracted position of each of said plurality of mobile thermal conduction elements, these form a peripheral envelope around said given longitudinal portion. The aforementioned envelope may alternatively not be entirely formed by the plurality of movable elements, but also with the aid of fixed elements relative to the main structure, for example each placed between two consecutive movable elements in the peripheral direction.

Preferably, said peripheral envelope of the given longitudinal part is constituted by two, three or four mobile thermal conduction elements, even if the number of these elements could be greater, without departing from the scope of the invention.

Still preferentially, said mobile thermal conduction structure comprises a plurality of movable thermal conduction elements distributed along a longitudinal direction of the storage device. This preferred feature highlights the "cut" nature of the movable structure in the longitudinal direction of the storage device. Nevertheless, it would alternatively be possible to provide that each movable element extends over substantially the entire length of the thermal conduction structure in the direction of the longitudinal axis of the storage device, without departing from the scope of the invention.

As mentioned above, it can be ensured that in the retracted position of each element of said mobile thermal conduction structure, it forms substantially the entirety of the lateral outer surface of said storage device. it reflects the fact that the entirety of the main structure is "covered" laterally by the mobile structure, although it could be otherwise, without departing from the scope of the invention. In this regard, it can be provided that only the upper and lower ends of the basket are not covered by the deployable structure of thermal conduction.

Preferably, at least one movable thermal conduction member, and preferably each of these elements, is biased towards its retracted position or towards its deployed position by elastic return means, for example of the spring type.

Preferably, the storage device comprises control means for generating the displacement of each movable thermal conduction element from its retracted position to its deployed position, and vice versa, said control means being operable from outside the storage device and more preferably operable externally from an upper end of the storage device. As such, it is preferably provided that said control means comprise a control rod passing through said main structure parallel to a longitudinal axis of said storage device. In addition, it can be arranged that said control means comprise a control member operable from a head plate of the storage device.

Finally, it is recalled that the storage device applies preferentially to transport and / or storage of fresh nuclear fuel assemblies, for example of the Mox type.

Another object of the present invention relates to a package comprising a housing cavity of a storage device for transporting and / or storing nuclear material, said package comprising a main structure and said housing cavity being delimited by a lateral inner surface. said package. According to the invention, the packaging also comprises a mobile thermal conduction structure forming at least a part of said inner lateral surface of the package, said mobile thermal conduction structure comprising at least one mobile thermal conduction element mounted on said structure primary so as to be releasably movable from a retracted position to an extended position as it approaches a longitudinal axis of said housing cavity.

Thus, the advantages described above relating to the storage device according to the present invention, characterize analogously the packaging according to the invention, since the common concept between these two entities lies in the provision of a conduction structure deployable thermal system to improve the heat transfer between the basket and the packaging, establishing a contact between these two entities, or, as mentioned above, by simply reducing the clearance initially provided between these two elements. In particular, even if the use of wide manufacturing tolerances leads to consider a large clearance between the package and the basket to allow loading of the latter, once it is housed inside the cavity, the structure Thermal conduction can then be deployed to increase the contact surfaces with the storage basket, which limits or even completely eliminates the adverse effects previously discussed relating to the presence of the large initial play forming thermal insulation.

Moreover, all of the preferential features described above and associated with the storage device can be applied in a similar manner to the packaging according to the invention. Nevertheless, only a few of them are recalled below.

Preferably, in at least one longitudinal half-section of the package passing through the longitudinal axis of said housing cavity and passing through the mobile thermal conduction structure, the sum of the lengths of each movable element of the mobile structure traversed, according to the longitudinal axis of said housing cavity, represents at least 20% of a total length of said housing cavity along its longitudinal axis.

Preferably, at least one movable element is articulated on said main structure of the package, along an axis of articulation parallel to the longitudinal axis of said housing cavity. Preferably, said hinge axis passes through an inner peripheral portion of said main structure of the package.

Preferably, the lateral inner surface of at least one movable element takes the form of an angular portion of a cylindrical surface having a longitudinal axis parallel to the longitudinal axis of said housing cavity, said angular portion being less than or equal to at 180 °.

Preferably, at least one movable element is articulated on said main structure of the package at a longitudinal edge of this element.

Still preferentially, at a given longitudinal portion of said main structure of the package, said movable structure has a plurality of movable thermal conduction elements, distributed peripherally, and thus serving to delimit the housing cavity. Preferably, in the retracted position of each of said plurality of movable thermal conduction elements, these form a portion of a peripheral ring disposed internally with respect to said given longitudinal portion.

Preferably, said peripheral ring portion is constituted by two, three or four mobile thermal conduction elements.

Preferably, said mobile thermal conduction structure comprises a plurality of movable thermal conduction elements distributed along a longitudinal direction of the housing cavity. Preferably, at least one movable thermal conduction element is held in its retracted position or in its deployed position by elastic return means.

Preferably, it further comprises control means for generating the displacement of each movable thermal conduction element from its retracted position to its deployed position, and vice versa, said control means being operable from outside the package and more preferably operable externally from an upper end of the package.

Preferably, the control means comprise a control rod passing through said main structure of the package, parallel to the longitudinal axis of said housing cavity.

Another object of the present invention relates to a container for the transport and / or storage of nuclear material, this container comprising a package and a storage device removably placed in said package, said package being a package such that described above, and / or said storage device being a storage device as described above.

In other words, the invention relates to a container for the transport and / or storage of nuclear material, this container comprising a package and a storage device removably placed in said package, and a movable structure of thermal conduction comprising at least one movable thermal conduction member arranged to be releasably movable from a retracted position to an extended position to reduce the clearance between the storage device and the package, or to both of these components mutually in contact, the mobile thermal conduction structure indifferently part of the storage device and / or packaging.

Finally, the invention also relates to a method of loading a storage device as described above in a package so as to form a container for the transport and / or storage of nuclear materials, the method comprising a step introducing said storage device into a cavity defined by the package with an inner side surface thereof, characterized in that it also comprises a subsequent step of deploying said mobile structure of thermal conduction. Preferably, this deployment is carried out so that each mobile thermal conduction member of said mobile structure comes into contact with said inner lateral surface delimiting said cavity of the package. Nevertheless, it is also possible to envisage a smaller deployment, not leading to the aforementioned contact, the purpose of which is to reduce the initially planned clearance between the basket and the package, so as to improve the heat transfer between these two elements. .

Other advantages and features of the invention will become apparent in the detailed non-limiting description below. BRIEF DESCRIPTION OF THE DRAWINGS

This description will be made with reference to the appended drawings among which; Figure 1 shows a schematic perspective view of a storage device for the transport and / or storage of nuclear fuel assemblies, according to a preferred embodiment of the present invention; Figure 2 shows a schematic longitudinal half-section of the storage device, taken along the line II-II of Figure 1;

- Figure 3 shows a cross-sectional view taken along the plane Pl of Figure 1;

- Figure 4 shows a partial perspective view of the storage device shown in the preceding figures, wherein the two movable thermal conduction elements surrounding a longitudinal portion of the main structure of the device have been only partially represented; Figure 5 shows a schematic perspective view of one of the two movable thermal conduction elements partially shown on the storage device of Figure 4;

- Figure 6 shows a longitudinal sectional view of the storage device, taken along the line VI-VI of Figure 3;

FIG. 7 represents a cross-sectional view of the storage device, taken along the line VII-VII of FIG. 6, one of the two mobile thermal conduction elements being represented in the retracted position, and the other in the deployed position;

- Figure 8 shows a schematic longitudinal sectional view of a container for the transport and / or storage of nuclear fuel assemblies, comprising the storage device shown in the preceding figures; Figure 9a shows a schematic cross-sectional view of the storage device, taken along the line IX-IX of Figure 8, the movable elements of thermal conduction being shown in the retracted position; Figure 9b is a schematic cross-sectional view of the storage device, taken along the line IX-IX of Figure 8, the movable thermal conduction elements being shown in the deployed position;

FIG. 10 is a detailed cross-sectional view of the storage device shown in the configuration of FIG. 9b;

- Figure 11 shows a longitudinal sectional view of the storage device, taken along the line XI-XI of Figure 10; and

Figures 12a and 12b show schematic views similar to those shown in Figures 9a and 9b, with the container in the form of another preferred embodiment of the present invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Firstly with reference to FIG. 1, one can see a storage device 2 for the transport and / or storage of nuclear fuel assemblies, according to a preferred embodiment of the present invention.

The storage device 2 is intended to be placed in a package (not shown in this figure) intended for the transport and / or storage of nuclear fuel assemblies (not shown), preferably fresh, for example of the Mox type.

As can be seen in Figure 1, the storage device 2 comprises a plurality of adjacent housings L arranged in parallel, the latter each extending along a longitudinal housing axis 3, parallel to a longitudinal axis 4 of the device / basket 2 The housings L are defined by a main structure 5 of the basket, also called central structure, and are each able to receive at least one fuel assembly of square or rectangular section, and preferably only one. They are each delimited by an inner surface, the cross section of which preferably takes the form of a square or a rectangle.

In the following description, the term "longitudinal" should be understood as parallel to the longitudinal axis 4 of the basket, and the term "transverse" must be understood as orthogonal to the same longitudinal axis 4.

The design of the main structure 5 of the storage device 2 may be of any form known to those skilled in the art, such as for example the type based on the stack of slabs traversed by housing delimiting folders, or of the type intended to obtain the housing L juxtaposed to each other through a plurality of structural assemblies with stacked and interlocking notches.

It is noted that the storage device 2 is shown in a vertical loading / unloading position of the fuel assemblies, different from the horizontal / recumbent position usually adopted during the transportation of the assemblies. Indeed, as is known to those skilled in the art, these assemblies are intended to be previously introduced into the housing L with the device 2 arranged vertically, namely resting on a bottom 6 located at one end of the device opposite to that bearing a head plate 11, through which the assemblies pass before entering their respective homes.

The storage basket 2 comprises a lateral outer surface 7, a large part of which is constituted by the lateral outer surface 12 of mobile elements 10 belonging to a mobile thermal conduction structure 8, which will be detailed below. Indeed, in the preferred embodiment described, this results in the fact that almost all of the main structure 5 is laterally covered by the movable structure 8, since only the upper 14 and lower 16 ends of the basket 2 are not covered by the moving elements of thermal conduction 10.

Still with reference to FIG. 1, it can be seen that the portion of the main structure 5 laterally covered by the movable structure 8, namely the portion between the ends 14 and 16 of the basket, is cut into three adjacent sections or longitudinal portions, referenced from top to bottom 18a to 18c. Naturally, the number of sections could be different, depending on the needs and constraints encountered.

At each of these sections 18a-18c, the structure 8 comprises two movable elements 10 distributed angularly / peripherally, and each extending over an angular sector of about 180 ° in order to jointly constitute a peripheral envelope around the longitudinal portion. concerned 18a-18c, and this when the movable elements 10 occupy a retracted position as will be described later.

The three peripheral envelopes thus formed are adjacent in the longitudinal direction of the basket 2, and can therefore be likened to one and the same substantially continuous envelope, extending all around the main structure 5, and substantially over almost the entire basket length 2.

In this regard, with reference to FIG. 2, it is preferably provided that in any longitudinal half-section of the device 2 passing through its axis 4 and passing through the mobile thermal conduction structure 8, the sum of the lengths 11 of each mobile element 10 crossed, along the axis 4, represents at least 20% of a total length 12 of the storage device 2 along the same axis 4. In other words, in the preferred embodiment described in which the total length 12 corresponds to the sum of the three lengths 11 to which the lengths of the two ends 14, 16 must be added, the following relation is verified:

3.11> 0.2.12

As such, it is indicated that the ratio 3.11 / 12 is preferably identical regardless of the longitudinal half-section considered, which reflects the fact that the deployable structure 8 has a constant length all around the main structure 5.

Referring now to Figure 3, it can be seen that for each of the longitudinal sections 18a-18c, each of the two movable elements 10 is hingedly mounted on the main structure 5, along an axis of articulation 20 parallel to the axis 4 .

Thus, for each of the two mobile elements 10, this hinge pin 20 is preferably placed so that it is located at an articulated longitudinal edge 22 of the element, and so that it passes through a peripheral portion 24 of the main structure 5, as is clearly visible in FIG.

Furthermore, still in this same figure, it can be seen that the lateral outer surface 12 of each of the two movable elements 10 takes the form of an angular portion of a cylindrical surface, of circular section and of a longitudinal axis parallel to the longitudinal axis 4, and preferably coincides with the latter when the movable member 10 occupies its retracted position shown.

As mentioned above, the angular portion is of the order of 180 °, which allows the two elements 10 to jointly form a closed envelope around the longitudinal section considered, whose lateral outer surface 12 constituting a part of the lateral outer surface 7 of the basket 2, takes the form of a cylindrical portion of circular section.

In the preferred embodiment described, the two hinged longitudinal edges 22 are substantially placed facing one another, and are therefore arranged diametrically opposite to the two longitudinal free edges 26 of the two movable elements. Obviously, in the retracted position of the latter as shown in Figure 3, the two longitudinal free edges 26 are also substantially placed opposite one another, and possibly in contact.

One of the peculiarities of the present invention lies in the fact that each of the two movable thermal conduction elements 10 is mounted on the main structure 5 so as to be able to be moved from the retracted position to a deployed position which will be described below. , away from the main structure 5, namely away from the axis 4 by pivoting along its hinge axis 20.

With reference now to FIG. 4, the intermediate longitudinal section 18b has been represented with only a part of its two associated moving elements, in order to better understand the design of the main structure 5, and to reveal a part of the control means allowing the moving elements of thermal conduction 10 to move.

Thus, it can be seen that the main structure 5 comprises transverse slats 30 spaced longitudinally from each other, their periphery jointly forming a single circumferential bearing surface of cylinder shape and circular section, intended to be married by a lateral inner surface of the associated mobile element 10, in the retracted position. The annular spaces 35 situated between two directly consecutive transverse slabs 30 are filled by semi-annular elements 36, each preferably taking the form of a half-ring of substantially square or rectangular cross-section, these elements 36 forming an integral part of the elements. mobile 10, as will be discussed below.

Thus, in each section 18a-18c, six annular spaces 35 are left free to be penetrated respectively by the six semi-annular elements 36 of the mobile elements 10. It is noted that these elements 36 participate strongly in the heat transfer between the movable element 10 and the main structure 5, at its wafers 30, this thermal transfer to improve the heat transfer between the basket and the cavity. For this, the required operating clearance between wafers 30 and the semi-annular elements 36 is set to be as small as possible.

As can be seen in FIG. 5 showing a movable thermal conduction element 10 intended to be placed around the section 18b of the basket of FIG. 4, this element can be roughly made using a hollow cylinder portion 38 defining the outer lateral surface 12 and extending over about 180 °, on which are reported six elements 36 each forming an inner portion of the associated movable member 10. The inner portions 36 are then preferably of the same longitudinal axis, also corresponding to the longitudinal axis of the hollow cylinder portion 38.

Moreover, in each section 18a-18c, two of the six annular spaces 35, left free to be penetrated by the internal portions 36, house a part of the control means for the setting in motion of these elements, as will now be be detailed with reference to Figures 4 to 7.

The control means firstly comprise a control rod 40 passing through the main structure 5 parallel to the longitudinal axis 4, this control rod 40 being situated generally between the free longitudinal edges 26 of the mobile elements 10, as this is the case. 3. The rod 40 extends substantially the entire length of the basket 4, crossing a periphery of the wafers 30, as can be seen in FIG. 6. In this same figure, it can be seen that the rod 40 carries an actuable actuator 42 arranged externally relative to the basket, and more precisely mounted on the head plate 11 from which it is accessible.

The control means further comprise, at two annular spaces 35 for respectively receiving two internal portions 36 of movable element 10, a sliding retaining module 44 cooperating with the free longitudinal edge 26 of each of the movable elements 10. As a indicative, the two elements concerned correspond to the second and the fifth elements 36 in the direction of the axis 4, although it could of course be otherwise, depending on the needs and constraints encountered.

More precisely and with reference to FIG. 6, it can be seen that each sliding retaining module 44 has two guide ramps 46 disposed on either side of the control rod 40, these ramps 46 cooperating respectively with two guided pins 48 respectively integral with two free edges 26 opposite, and more specifically two internal portions 36 opposite.

In addition, each module 44 is mounted via a threaded connection on the control rod 40, which performs the function of worm. Therefore, in case of rotation of the rod 40 according to its own axis, through the control member 42, each of the holding modules 40 moves relatively relative to the main structure 5, in the direction of axis 4.

The permanent contact between the guide ramp 46 and its associated pin 48 is obtained by the resilient biasing means, spring-type, preferably compression spring. This is shown by way of illustrative example in FIG. 7, showing the presence of springs 50 between the moving elements and the main structure 5, and more precisely between the hollow cylinder portion 38 and one or more of the slabs 30. Naturally, the number and arrangement of the springs 50 are determined according to the needs and constraints encountered, their action tending to push the movable elements of thermal conduction 10 to their deployed position.

It is noted that in Figure 7, the upper movable member 10 is shown in its retracted position, while the lower movable member 10 is shown in its extended position in which it is spaced from the main structure 5, as shown the free space 52 between the hollow cylinder portion 38 and the periphery of the slabs 30.

With such a configuration, when the modules 44 are moved automatically in response to the rotation of the rod 40, each guided pin 48 moves along its associated inclined ramp 46 with which it maintains the contact, thanks to the action exerted by Permanently by the springs 50. This is observed both when it is desired to move the elements 10 to their retracted position, that is to say when the rotation of the rod 40 exerted leads to bring the pins 48 of the rod 40 , when it is desired to move the elements 10 towards their deployed position, that is to say when the rotation of the rod 40 exerted leads to the removal of the pins 48 of this rod 40. This last phase in particular reflects the fact that the free edges 26 deviate from the main structure 5, following a pivoting of the elements 10 according to their respective axes of articulation 20.

Finally, it is indicated, as shown in FIG. 6 for the section 18c, that each mobile element 10 is equipped with two guided pins 48 spaced longitudinally, each of them cooperating with a separate holding module 44.

Referring to Figure 8, we see a container 100 also object of the present invention, comprising generally a package 102 within which there is a storage device 2 as described above. The device 2 is intended to be placed in a cavity 112 of the package 102, as shown schematically in FIG. 8 on which it is also possible to see the longitudinal axis 104 of the package 102 coinciding with the longitudinal axis 4 of the storage device, this package 102 having essentially a bottom 106 on which the device 2 is intended to rest in a vertical position, a cover 108, and a lateral body 110 extending around the axis longitudinal 104.

It is this lateral body 110 which defines the housing cavity 112, with the aid of a lateral internal surface 114 of substantially cylindrical shape and of circular section, and of axis coinciding with the axes 104 and 4 above.

The method of loading the device 2 in the package 102, also object of this invention, will be described with reference to Figures 8 to 9b.

First, before the introduction of the basket into the housing cavity 112, the movable elements 10 are moved in their retracted position using the control means described above, in order to facilitate this operation of introduction of the basket, usually done vertically.

Once this introduction has been completed, the basket 2 is found in the configuration shown schematically in FIG. 9a, in which its lateral external surface, namely the surfaces 12 of the mobile elements 10, are spaced from the lateral internal surface 114 delimiting the cavity of FIG. 112. The reference J placed between the surfaces 12 and 114 thus symbolizes the presence of a large initial clearance between the basket and the cavity of the package, before deployment of the mobile thermal conduction structure.

Therefore, a subsequent step of deploying this mobile thermal conduction structure is implemented, so that each movable thermal conduction member thereof comes into contact with the inner side surface 114 to provide the transfer function. thermal, as shown in Figure 9b.

This is achieved by the actuation of the control means by an operator, which causes, under the action of the springs provided for this purpose, the simultaneous pivoting of the movable elements 10 along their axes articulation 20, so that they deviate from the axis 4.

The contact obtained between each movable element 10 and the cavity 112 takes the form of a linear contact along a generatrix common to the surfaces 12 and 114, as shown schematically in the references 116 in Figure 9b.

The longitudinal free edges 26 initially facing each other in pairs are therefore separated from each other, in the sense that they follow the movement of the moving elements 10 away from the axis 4 and the main structure 5, as shown Figure 10.

The deployment of the movable elements 10 reveals the free space 52, which is situated between the lateral inner surface 122 of the hollow cylinder portion of the movable element concerned 10, and the circumferential bearing surface 124 defined by the periphery of the 30, as shown in Figure 11. However, to ensure the heat transfer between the main structure 5 and the movable elements of thermal conduction 10, it is expected that in the deployed position shown in this figure 11, the semi-internal portions rings 36 continue to be partially in contact with the two wafers 30 located on either side of each portion 36. The two surface contacts observed for each inner portion 36 of the movable elements 10 are respectively located in two distinct transverse planes, and referenced 126 in FIG. 11 also showing the new relative position of the guided pieces 48, by relative to their respective ramps 46 with which they are in contact.

Once the mobile structure 8 deployed, the cavity 112 is then closed by the lid 108 of the container.

Referring now to Figures 12a and 12b, the container 100 is in the form of another preferred embodiment, in that it is the package 102 that carries the movable thermal conduction structure 8, and not the storage device 2 as was the case in the previous mode.

All the technical characteristics relating to the basket 2 described above can be applied identically or similarly to the package 102 which will briefly be presented hereinafter, and which is also the subject of the present invention.

Thus, the inner lateral surface 114 delimiting the housing cavity 112 is at least partially defined by the lateral inner surfaces of the movable thermal conduction elements 10, which are now mounted articulated on the main structure 130 of the package, and more specifically on an inner peripheral portion thereof.

Each movable member 10 is then mounted on the main structure 130 so as to be movable from a retracted position shown in Fig. 12a to an extended position shown in Fig. 12b, approaching the longitudinal axis 104 of the housing cavity 112, thus away from the main structure 130 radially inwardly.

In these two figures, it can be seen that in contrast to the previous embodiment, in the retracted position of the elements 10, the free longitudinal edges 26 facing two by two are substantially spaced from each other, while in the deployed position elements 10 allowing the contact 116 with the lateral outer surface 7 of the basket 2, the longitudinal longitudinal edges 26 facing each other in pairs are substantially close to each other or in contact in pairs.

Of course, various modifications may be made by those skilled in the art to the invention which has just been described, solely by way of non-limiting examples.

Claims

1. A storage device (2) for the transport and / or storage of nuclear material, comprising a main structure (5) defining at least one housing (L) for containing said nuclear material, characterized in that it also comprises a mobile thermal conduction structure (8) forming at least a part of a lateral external surface (7) of said storage device, said mobile thermal conduction structure (8) comprising at least one movable thermal conduction element (10) mounted on said main structure (5) so as to be releasably movable from a retracted position to an extended position away from said main structure (5).

2. Storage device (2) according to claim 1, characterized in that in at least one longitudinal half-section of the storage device passing through a longitudinal axis (4) thereof and passing through the mobile thermal conduction structure ( 8), the sum of the lengths (11) of each movable element (10) of the mobile structure traversed, along the longitudinal axis (4) of the storage device, represents at least 20% of a total length (12) of said storage device along its longitudinal axis (4).

Storage device (2) according to claim 1 or claim 2, characterized in that at least one movable element (10) is articulated on said main structure (5), along an axis of articulation (20) parallel to a longitudinal axis (4) of said storage device.

4. Storage device (2) according to claim 3, characterized in that said hinge axis (20) passes through a peripheral portion of said main structure (5).

5. Storage device (2) according to any one of the preceding claims, characterized in that the outer lateral surface (12) of at least one movable element (10) takes the form of an angular portion of a surface cylindrical longitudinal axis parallel to a longitudinal axis (4) of said storage device, said angular portion being less than or equal to 180 °.

6. Storage device (2) according to any one of the preceding claims, characterized in that at least one movable element (10) is articulated on said main structure (5) at a longitudinal edge (22) of this element.

7. Storage device (2) according to any one of the preceding claims, characterized in that around a given longitudinal portion (18a- 18c) of said main structure (5), said movable structure (8) has a plurality of movable thermal conduction elements (10) distributed peripherally.

8. Storage device (2) according to claim 7, characterized in that in the retracted position of each of said plurality of movable thermal conduction elements (10), they form a peripheral envelope around said given longitudinal portion (18a-18c).

9. Storage device (2) according to claim 8, characterized in that said peripheral envelope of the given longitudinal portion (18a- 18c) is constituted by two, three or four movable thermal conduction elements (10).

10. Storage device (2) according to any one of the preceding claims, characterized in that said mobile thermal conduction structure (8) comprises a plurality of movable thermal conduction elements (10) distributed along a direction longitudinal storage device.

11. Storage device (2) according to any one of the preceding claims, characterized in that it comprises elastic return means

(50) reminding at least one movable thermal conduction member (10) to its retracted position or to its deployed position.

12. Storage device (2) according to any one of the preceding claims, characterized in that it comprises control means for generating the displacement of each movable element of thermal conduction (10) from its retracted position to its deployed position, and vice versa, said control means being operable from outside the storage device.

13. Storage device (2) according to claim 12, characterized in that said control means comprise a control rod (40) passing through said main structure (5) parallel to a longitudinal axis (4) of said storage device.

14. Storage device (2) according to any one of the preceding claims, characterized in that it applies to the transport and / or storage of fresh nuclear fuel assemblies.

A package (102) comprising a housing cavity (112) of a storage device (2) for transporting and / or storing nuclear material, said package comprising a main structure (130) and said housing cavity (112). ) being delimited by a lateral interior surface (114) of said package, characterized in that it also comprises a movable thermal conduction structure (8) forming at least a part of said lateral inner surface (114) of the package, said mobile thermal conduction structure (8) comprising at least one movable thermal conduction member (10) mounted on said main structure (130) so as to be releasably movable from a retracted position toward an extended position as it approaches a longitudinal axis (104) of said housing cavity (112).

Container (100) for the transport and / or storage of nuclear material, which container comprises a package (102) and a storage device (2) removably placed in said package, said package being a package according to claim 15, and / or said storage device being a storage device according to any one of claims 1 to 14.

17. A method of loading a storage device (2) according to any one of claims 1 to 14 in a package (102) so as to form a container (100) for the transport and / or storage of nuclear material, the method comprising a step of introducing said storage device (2) into a housing cavity (112) defined by the package with an inner side surface (114) thereof , characterized in that it also comprises a subsequent step of deploying said mobile thermal conduction structure (8).