EP1576621A2 - Container for the storage/transport of unirradiated radioactive materials such as nuclear fuel assemblies - Google Patents

Container for the storage/transport of unirradiated radioactive materials such as nuclear fuel assemblies

Info

Publication number
EP1576621A2
EP1576621A2 EP03786049A EP03786049A EP1576621A2 EP 1576621 A2 EP1576621 A2 EP 1576621A2 EP 03786049 A EP03786049 A EP 03786049A EP 03786049 A EP03786049 A EP 03786049A EP 1576621 A2 EP1576621 A2 EP 1576621A2
Authority
EP
European Patent Office
Prior art keywords
container
main structure
packaging
internal wall
spacing means
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
EP03786049A
Other languages
German (de)
French (fr)
Other versions
EP1576621B1 (en
EP1576621A3 (en
Inventor
Benoit Alaurent
Christian Reynaud
Jean-Pierre Bersegol
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
TN International SA
Original Assignee
Cogema Logistics SA
TN International SA
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Cogema Logistics SA, TN International SA filed Critical Cogema Logistics SA
Publication of EP1576621A2 publication Critical patent/EP1576621A2/en
Publication of EP1576621A3 publication Critical patent/EP1576621A3/en
Application granted granted Critical
Publication of EP1576621B1 publication Critical patent/EP1576621B1/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Classifications

    • GPHYSICS
    • G21NUCLEAR PHYSICS; NUCLEAR ENGINEERING
    • G21FPROTECTION AGAINST X-RADIATION, GAMMA RADIATION, CORPUSCULAR RADIATION OR PARTICLE BOMBARDMENT; TREATING RADIOACTIVELY CONTAMINATED MATERIAL; DECONTAMINATION ARRANGEMENTS THEREFOR
    • G21F5/00Transportable or portable shielded containers
    • G21F5/06Details of, or accessories to, the containers
    • G21F5/08Shock-absorbers, e.g. impact buffers for containers

Definitions

  • the present invention relates to a container for the storage / transport of non-irradiated radioactive materials such as fresh nuclear fuel assemblies, intended to constitute the energy source of nuclear power plants.
  • the containers for non-irradiated radioactive materials are of substantially cylindrical or parallelepiped shape.
  • These containers usually include an outer packaging, consisting of one or more side faces, a fixed bottom, a cover, and one or more removable protective covers.
  • Each of the elements constituting the packaging, and more particularly the side face (s) of the latter, is composed of a single layer or of a stack of layers made of various materials.
  • the side (s) of the packaging are • in the form of a stack of layers, this . last one has a layer from the inner end, generally taking the form of a metal plate.
  • the metal plate (s) form an internal lateral wall of the packaging, the latter defining a cavity inside which the radioactive materials are able to be housed.
  • the cavity defined by the lateral internal wall is substantially cylindrical with a circular section. It is also specified that the cavity is completely closed by means of the fixed bottom and the cover of the packaging, situated respectively at the ends of the lateral internal wall.
  • Non-irradiated radioactive materials such as fresh nuclear fuel assemblies composed for example of a mixture of uranium and plutonium oxides, extend longitudinally and have a square section.
  • the latter In order to precisely position these assemblies in the container cavity, the latter also has a main structure of usually substantially cylindrical shape of circular section, this structure defining a plurality of housings each capable of receiving at least one fuel assembly.
  • the main structure also called “basket” or “rack” for storage, is then designed so that it can be introduced into the cavity of the packaging, so as to be held there in relation to the packaging, once inserted .
  • the main structure generally has .a diameter substantially identical to inside diameter of the lateral internal wall of the package, to the clearance.
  • the main structure can then be in the form of discs spaced or stacked on each other, along a longitudinal main axis of the container.
  • the discs generally each comprise a plurality of orifices.
  • each orifice can be traversed by a tube designed to receive one or more assemblies of nuclear fuel.
  • the main structure is positioned in the cavity of the packaging so that the clearance between the main structure and the lateral internal wall is low or zero, in order to ensure satisfactory heat exchanges between these two components of the container.
  • the stacks of layers making up the container packaging have been the subject of numerous studies, in particular to meet the needs specific to the tests concerning the fall on a punch and the fall from 9 meters, these tests must be passed in an order such that it provides the maximum damage.
  • the punching test consists in raising the container one meter above a cylindrical punch fifteen centimeters in diameter, then dropping it by gravity on the punch. To pass this test as well as that of falling from nine meters, it is necessary to demonstrate that the main structure of the container, that is to say the basket in which the nuclear fuel assemblies rest, does not undergo any deformation.
  • multi-layer packaging there are first known stacks with anti-punch armor comprising three elements superimposed on each other. To achieve such stacks, the elements are positioned so that an external plate and an internal steel plate sandwich a fire-resistant layer, the latter being made of a material with low crushing stress making it possible to absorb the falling energy .
  • the object of the invention is therefore to propose a container for the storage / transport of non-irradiated radioactive materials such as nuclear fuel assemblies, the container comprising a main structure and a package comprising a lateral internal wall defining a cavity inside. which is able to accommodate the main structure, the container at least partially overcoming the drawbacks mentioned above relating to the embodiments of the prior art.
  • the object of the invention is to present a container whose design makes it possible to meet regulatory safety requirements relating to the transport / storage of nuclear materials, while having a total mass which is greatly weakened compared to the containers of the prior art, in order to comply with ever greater operating constraints.
  • the subject of the invention is a container for the storage / transport of non-irradiated radioactive materials such as nuclear fuel assemblies, the container comprising a main structure and a package comprising a lateral internal wall defining a cavity at the inside of which the main structure is capable of being housed, the latter defining a plurality of housings each capable of receiving at least one fuel assembly.
  • the container further comprises spacer means of the main structure with respect to 'packaging, spacing means being able to avoid any direct contact between the lateral internal wall and the main structure, so as to allow a punctual deformation of this lateral internal wall of the packaging during a punching test.
  • the specific design of the container according to the invention results from an approach completely different from the conventional approach previously practiced for designing such containers.
  • the main condition for satisfying the regulatory safety requirements relating to the transport / storage of nuclear materials being to demonstrate that the main structure containing the fuel assemblies is not damaged following the various drop tests of the container, this technical constraint has always been interpreted as a need to preserve the lateral internal wall of the packaging intact, following the implementation of these various tests.
  • the invention has been made by departing from this conventional practice, by providing a package whose lateral internal wall is capable of deforming in a punctual manner following mechanical stresses exerted on the packaging externally, such as those exerted by a punch during the punching test. So that a deformation of the lateral internal wall does not damage the main structure of the container, unlike all the containers of the prior art, no direct contact has been provided between this lateral internal wall and the main structure, so that the deformation cannot be transmitted.
  • the main structure of the container containing the fuel assemblies is able to remain intact following the completion of the various drop tests, despite the deformation of the lateral internal wall of the packaging caused. Consequently, the design of this package can then be considerably simplified. Indeed, the specific design retained for the container according to the invention allowing the lateral internal wall of the packaging to be deformed during the drop test on punch, this packaging no longer needs to be produced using 'complex stacks of oversized layers, and can therefore undergo large simplifications as well as a significant reduction in mass and thickness compared to previously offered packaging.
  • the means for spacing the main structure relative to the packaging are provided between the main structure and the lateral internal wall of the packaging, the spacing means having '' a fuse function mechanical in order to deform during a punctual deformation of the lateral internal wall of the packaging, occurring following the punching test.
  • the spacing means are also designed to resist, and therefore not to deform, following the mechanical stresses encountered during falls from 9 meters.
  • the space provided between the lateral internal wall of the packaging and the main structure is at least partially filled by the spacing means, so as to provide an additional function of heat transfer between these elements. Note that this function is made possible due to the small or zero clearance existing between on the one hand the spacing means and the main structure, and on the other hand the lateral internal wall of the packaging and these same means of spacing.
  • the spacing means are advantageously designed to fulfill the role of a mechanical fuse during a fall on a punch, the latter generally causing a punctual deformation of the lateral internal wall of the packaging.
  • the spacing means are directly damaged under the effect of the deformation of the lateral internal wall, without transmitting this deformation to the main structure of the container, which remains completely intact.
  • the spacing means are also designed not to deform during the 9 meter drop tests, more particularly during horizontal falls, under the inertia of the main structure responsible for fuel assemblies.
  • the spacing means are designed so as to be able to fully fulfill the functions of a mechanical fuse, even when the falls on a punch are made after the falls from 9 meters.
  • the spacing means are composed of a plurality of deformable sectors distributed around the main structure of the container, these sectors extending over the entire length or only over part of the length of the main structure of the packaging. , or being stacked on top of each other in a direction parallel to a longitudinal main axis of the container.
  • the deformable sectors are arranged next to each other so as to form strips encircling the main structure.
  • the deformable sectors are made of a material with low crushing stress such as wood, plastic foam or honeycomb confined between two metal sheets, or still metallic elements taking the form of two concentric sheets separated by reinforcements.
  • the metal elements are preferably made of aluminum or one of its alloys.
  • the deformable sectors are fixed to the main structure of the packaging, and completely or only partially cover the main structure of the container.
  • the means for spacing the main structure relative to the packaging are provided on a cover and / or a fixed bottom of the packaging, the lateral internal wall of the packaging and the main structure being separated by an empty space.
  • This solution remains very advantageous insofar as it makes it possible to obtain a relatively light container, due to the absence of material between the lateral internal wall of the packaging and the main structure.
  • the main structure of the container has a substantially cylindrical shape of circular section, and the inner side wall of the package and the main structure are separated by a form space. substantially annular.
  • Figure 1 shows a perspective view of a container ' for the storage / transport of non-irradiated nuclear material, according to a first mode. preferred embodiment of the present invention
  • - Figure 2 shows a partial sectional view of the container shown in Figure 1, along a plane perpendicular to the main longitudinal axis of this container
  • 3 shows a perspective view of a deformable sector such as that used in the spacing means of the container shown in Figure 1
  • 4 shows a schematic perspective view of a main structure of the container shown in Figure 1, provided with a plurality of deformable sectors
  • 5 shows a schematic sectional view explaining the behavior of a container such as that shown in Figure 1, following the execution of a punching test
  • FIG. 1 shows a perspective view of a container ' for the storage / transport of non-irradiated nuclear material, according to a first mode. preferred embodiment of the present invention
  • - Figure 2 shows a partial sectional view of the container shown in Figure 1, along a plane perpendicular to the main longitudinal axi
  • FIG. 6 shows a partial perspective view of a container for the storage / transport of non-irradiated nuclear material, according to a second preferred embodiment of the present invention.
  • Figure 7 shows a partial sectional view of the container shown in Figure 6, along a plane perpendicular to the main longitudinal axis of this container.
  • FIG. 1 we see a container 1 for the storage / transport of non-irradiated radioactive material such as fresh nuclear fuel assemblies (not shown) ' , according to a first preferred embodiment of the present invention.
  • the container 1 comprises a packaging 2 as well as a main structure 4 of the basket type, capable of being housed inside the packaging 2 of the container 1.
  • the package 2 consists of a side face 6 of substantially annular shape, a fixed bottom 8, a cover 10, and two removable protective covers 12 and 14 arranged at the ends of the package 2.
  • the side face 6 of the package 2 is unique, but could of course be composed of several elements attached to each other, without departing from the scope of the invention.
  • This lateral face 6 is composed of an internal ferrule 16 and an external ferrule 18 centered on a main longitudinal axis 19 of the container 1, these ferrules 16 and 18 being spaced and held relative to one another by the 'through stiffeners 20, which also have the function of conducting heat through a neutron protection 22, also located between the two ferrules 16 and 18.
  • the internal ferrule 16 of the lateral face 6 of the package 2 has a lateral internal wall 24, defining a cavity inside which is able to be housed the main structure 4 of the container 1. As can be seen in Figures 1 and
  • the main structure 4 resting in the cylindrical cavity defined by the lateral internal wall 24 comprises a plurality of housings 26, each capable of receiving an assembly of fresh nuclear fuel.
  • the main structure 4 of the container 1 preferably has a substantially cylindrical shape of circular section, and can be produced according to known conventional techniques.
  • the structure 4 is obtained by a stack of discs 28 along the longitudinal main axis 19 of the container 1. A plurality of orifices made on each of the discs 28 allows thus defining the housings 26, into which the nuclear fuel assemblies may be introduced.
  • the container 1 also comprises means for spacing the main structure 4 relative to the packaging 2, the spacing means being able to avoid any direct contact between the lateral internal wall 24 and the main structure 4, so as to allow a specific deformation of this lateral internal wall 24 of the package 2 during a punching test.
  • the spacing means 30 are provided between the main structure 4 and the lateral internal wall 24 of the package 2, in order to ensure in particular a heat transfer function between the elements 2 and 4.
  • the main structure 4 indeed has an outside diameter smaller than the diameter of the lateral internal wall 24, this specific design of the container 1 resulting in the formation of a space of substantially annular shape. , inside which the spacing means 30 can be accommodated.
  • the particular arrangement of the spacing means 30 can then allow these means to fulfill a mechanical fuse function allowing punctual deformations of the internal lateral wall 24 of the packaging 2. This function will be more fully explained below.
  • the spacing means 30 consist of a plurality of deformable sectors 32, distributed around the main structure 4, on which they are preferably assembled by screwing.
  • the deformable sectors 32 can first of all extend over substantially the entire length of the main structure 4, as shown by the strip 34. Furthermore, the deformable sectors 32 can also be stacked on top of each other in a direction parallel to the main longitudinal axis 19 of the container 1, as shown by the strip 36.
  • deformable sectors 32 can also be arranged one beside the other so as to form annular bands (not shown) encircling the main structure 4 and distributed over the entire length of this structure 4 or only at the two ends thereof.
  • the diversity of arrangements of the deformable sectors 32 on the main structure 4 is very large, and can lead to total or partial covering of the main structure 4 of the container 1.
  • the location of the sectors 32 on the structure 4 can therefore be judiciously chosen, in order to best respond to the mass constraints and the mechanical constraints to be met by the container 1.
  • each deformable sector 32 consists of a metallic element preferably made of aluminum or one of its alloys, this element taking the form of two concentric sheets 40 and 42 of identical axis to the main longitudinal axis 19 of the container 1, the sheets 40 and 42 being separated by reinforcements 44 ( Figure 3).
  • the metal elements constituting the deformable sectors 32 are extruded, but could also be produced by mechanical welding or any other conventional technique, without departing from the scope of the invention.
  • the sheet-like parts 40 and 42 are respectively in contact with the main structure 4, and the lateral internal wall 24.
  • the elements 40, 42 and 44 each have a lower thickness. about half the thickness of the inner shell 16.
  • the reinforcements 44 each extend over the entire length of the sheet-shaped parts 40 and 42, and are inclined with respect to a radius of circle concentric with the sheet-shaped parts 40 and 42.
  • the reinforcements 44 are arranged so that two successive reinforcements 44 are inclined in an opposite direction, so as to be in phase opposition.
  • the angle of inclination of the reinforcements can be around ⁇ 20 °.
  • the deformable sectors 32 can take any other form and be formed using other materials, insofar as these are capable of spacing the main structure 4 from packaging 2,. and likely to fulfill the role of mechanical fuse described below. Still by way of nonlimiting example, the deformable sectors 32 can then be made of a material with low crushing stress such as plastic foam, honeycomb, or wood such as balsa, confined or not between two metal sheets.
  • the packaging 2 of the container 1 comes into contact with a punch 46 of approximately 150 mm in diameter, this punch 46 causes significant local mechanical stresses on the packaging 2, so that the lateral face 6 is deformed over its whole thickness in an area located opposite the punch 46.
  • the packaging 2 is preferably designed so that following such a punching test, the internal shell 16 of this packaging 2 is deformed but not perforated. In this way, the internal shroud 16 of the packaging 2 is deformed by penetrating into the annular space of axis 19 initially provided between the internal lateral wall 24 and the main structure 4 of the container 1, this annular space being occupied by the spacing means 30.
  • the deformable sector or sectors 32 of the spacing means 30 located opposite the deformation of the lateral internal wall 24 then play their role of mechanical fuse by degrading directly following the impact of the lateral internal wall 24, without transmitting the deformation to the main structure 4 of the container 1. It is also indicated that the deformation of the lateral internal wall 24 takes place as if no element existed between the structure 4 and this lateral internal wall 24.
  • the sectors 32 are designed so that their deformation energy is negligible compared to the energy involved when falling on the punch 46, largely absorbed by the point deformation of the side face 6 of the package 2.
  • the sheet metal part 42 is deformed under the effect of the deformation of the lateral internal wall 24.
  • the reinforcement 44 located near this deformation are also deteriorated, always so that the deformation of the lateral internal wall 24 is not transmitted to the main structure 4 of the container 1.
  • the deformable sectors 32 do not necessarily follow the entire surface of the internal wall lateral 24, it is therefore possible to encounter cases in which the deformation of this lateral internal wall 24 is located in an area devoid of spacing means 30, and therefore of deformable sectors 32.
  • the lateral internal wall 24 then deforms quite simply in the vacuum of the annular space formed between the elements 2 and 4, according to substantially the same amplitude as that which would have been obtained in the presence of deformable sectors 32, still due to the main function of mechanical fuse of these sectors.
  • the spacing means 30 of the container 1 allow a punctual deformation of the lateral internal wall 24, the amplitude of this deformation being limited by the initial thickness of the space present between the lateral internal wall 24 and the main structure. 4, so that this wall 24 does not directly strike the structure 4 of the container 1.
  • the thickness of the annular space may for example be fixed so that the maximum deformation of the lateral internal wall 24, caused by a punch 46 under stress conditions similar to those encountered during regulatory tests, is compatible with this thickness.
  • the spacing means 30 are also advantageously designed so as to generally resist mechanical stresses due to the significant inertia of the main structure 4 generated during falls of 9 meters, more particularly during horizontal falls, usually not causing deformation of the side face 6 of the package 2.
  • FIGS. 6 and 7 there is shown partially a container 100 for the storage / transport of non-irradiated radioactive material such as fresh nuclear fuel assemblies (not shown), according to a second preferred embodiment of the present invention.
  • the annular space provided between the main structure 4 and the lateral internal wall 24 is no longer partially or completely filled by the deformable sectors 32 of the first embodiment, but remains an empty space 150 avoiding any direct contact between the lateral internal wall 24 and the main structure 4, so as to allow a punctual deformation of this lateral internal wall 24 of the package 2 during a punching test.
  • the spacing means 130 are provided on the fixed bottom 8 or on the cover 10 of the package 2, or preferably on both. These spacing means 130 thus make it possible to center the main structure 4 on the main longitudinal axis 19 of the container 100, so as to obtain an empty annular space 150 of substantially constant thickness.
  • the spacing means 130 comprise for example a plurality of centering means 152, provided on the fixed bottom 8 and on the cover 10 and directed towards the interior of the container 100 (only the means centering 152 integral with the cover 10 being shown).
  • Each centering means 152 is arranged along an axis identical to that of a housing 26 of the main structure 4, so as to be able to penetrate this same housing 26.
  • the centering means 152 placed on the cover 10 and the bottom 8 of the packaging 2 are able to laterally support the main structure 4, in order to maintain it with respect to the lateral internal wall 24 of the container 100.
  • any other spacing means 130 can be envisaged between a share the main structure 4 and secondly the fixed bottom 8 and / or the cover 10 of the package 2, without departing from the scope of the invention.
  • the lateral internal wall 24 of the container 100 then simply deforms in the void of the annular space 150 formed between the elements 2 and 4, according to substantially the same amplitude as that which would have been obtained in the presence of spacing means acting as a mechanical fuse, interposed between the internal lateral wall 24 and the main structure 4.
  • spacing means acting as a mechanical fuse interposed between the internal lateral wall 24 and the main structure 4.

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  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • High Energy & Nuclear Physics (AREA)
  • Packages (AREA)
  • Monitoring And Testing Of Nuclear Reactors (AREA)
  • Filling Or Discharging Of Gas Storage Vessels (AREA)

Abstract

The invention relates to a container (1) which is intended for the storage/transport of unirradiated radioactive materials. The inventive container consists of a main structure (4) and a casing (2) comprising an inner lateral wall defining a cavity in which the main structure (4) can be housed. The aforementioned main structure defines a plurality of housings (26) which can receive at least one fuel assembly. According to the invention, the container also comprises separation means (3) between the main structure and the casing, which prevent any direct contact between the inner lateral wall (24) and the main structure (4), such as to enable localised deformation of the inner lateral wall of the casing during punch testing.

Description

CONTENEUR POUR LE STOCKAGE/TRANSPORT DE MATIERES CONTAINER FOR STORAGE / TRANSPORT OF MATERIALS
RADIOACTIVES NON IRRADIEES TELLES QUE DES ASSEMBLAGESNON-IRRADIATED RADIOACTIVES SUCH AS ASSEMBLIES
DE COMBUSTIBLE NUCLEAIRENUCLEAR FUEL
DESCRIPTIONDESCRIPTION
DOMAINE TECHNIQUE La présente invention se rapporte à un conteneur pour le stockage/transport de matières radioactives non irradiées telles que des assemblages de combustible nucléaire frais, destinés à constituer la source d'énergie des centrales nucléaires.TECHNICAL FIELD The present invention relates to a container for the storage / transport of non-irradiated radioactive materials such as fresh nuclear fuel assemblies, intended to constitute the energy source of nuclear power plants.
ETAT DE LA TECHNIQUE ANTERIEURESTATE OF THE PRIOR ART
De manière classique, les conteneurs pour matières radioactives non irradiées sont de forme sensiblement cylindrique ou parallélépipédique .Conventionally, the containers for non-irradiated radioactive materials are of substantially cylindrical or parallelepiped shape.
Ces conteneurs comprennent habituellement un emballage extérieur, composé d'une ou plusieurs faces latérales, d'un fond fixe, d'un couvercle, et d'un ou plusieurs capots de protection amovibles.These containers usually include an outer packaging, consisting of one or more side faces, a fixed bottom, a cover, and one or more removable protective covers.
Chacun des éléments constituant l'emballage, et plus particulièrement la/les faces latérales de ce dernier, est composé d'une couche unique ou d'un empilement de couches réalisées en matériaux divers .Each of the elements constituting the packaging, and more particularly the side face (s) of the latter, is composed of a single layer or of a stack of layers made of various materials.
A cet égard, lorsque la/les faces latérales de l'emballage se trouvent sous la forme d'un empilement de couches, , ce. dernier comporte une couche d^ extrémité intérieure, prenant généralement la forme d'une plaque métallique. Ainsi, la/les plaques métalliques forment une paroi interne latérale de l'emballage, celle-ci définissant une cavité à l'intérieur de laquelle sont aptes à être logées les matières radioactives. Typiquement, la cavité définie par la paroi interne latérale est sensiblement cylindrique de section circulaire. Il est par ailleurs précisé que la cavité est totalement fermée par l'intermédiaire du fond fixe et du couvercle de l'emballage, situés respectivement aux extrémités de la paroi interne latérale .In this regard, when the side (s) of the packaging are in the form of a stack of layers, this . last one has a layer from the inner end, generally taking the form of a metal plate. Thus, the metal plate (s) form an internal lateral wall of the packaging, the latter defining a cavity inside which the radioactive materials are able to be housed. Typically, the cavity defined by the lateral internal wall is substantially cylindrical with a circular section. It is also specified that the cavity is completely closed by means of the fixed bottom and the cover of the packaging, situated respectively at the ends of the lateral internal wall.
Les matières radioactives non irradiées, telles que les assemblages de combustible nucléaire frais composés par exemple d'un mélange d'oxydes d'uranium et de plutonium, s'étendent longitudinalement et disposent d'une section carrée.Non-irradiated radioactive materials, such as fresh nuclear fuel assemblies composed for example of a mixture of uranium and plutonium oxides, extend longitudinally and have a square section.
Afin de positionner précisément ces assemblages dans la cavité du conteneur, celui-ci dispose également d'une structure principale de forme habituellement sensiblement cylindrique de section circulaire, cette structure définissant une pluralité de logements chacun apte à recevoir au moins un assemblage de combustible. La structure principale, également appelée « panier » ou « râtelier » ' de rangement, est alors conçue de manière à pouvoir être introduite dans la cavité de l'emballage, de façon à y être maintenue par rapport à l'emballage, une fois insérée . La structure principale dispose généralement d'.un diamètre sensiblement identique au diamètre intérieur de la paroi interne latérale de l'emballage, au jeu près.In order to precisely position these assemblies in the container cavity, the latter also has a main structure of usually substantially cylindrical shape of circular section, this structure defining a plurality of housings each capable of receiving at least one fuel assembly. The main structure, also called “basket” or “rack” for storage, is then designed so that it can be introduced into the cavity of the packaging, so as to be held there in relation to the packaging, once inserted . The main structure generally has .a diameter substantially identical to inside diameter of the lateral internal wall of the package, to the clearance.
Dans les solutions les plus répandues, la structure principale peut alors se présenter sous la forme de disques espacés ou empilés les uns sur les autres, selon un axe principal longitudinal du conteneur. Les disques comprennent généralement chacun une pluralité d'orifices. A cet égard, lorsque les disques sont espacés, chaque orifice peut être traversé par un tube conçus pour recevoir un ou plusieurs assemblages de combustible nucléaire.In the most widespread solutions, the main structure can then be in the form of discs spaced or stacked on each other, along a longitudinal main axis of the container. The discs generally each comprise a plurality of orifices. In this regard, when the discs are spaced, each orifice can be traversed by a tube designed to receive one or more assemblies of nuclear fuel.
En outre, la structure principale est positionnée dans la cavité de l'emballage de sorte que le jeu entre la structure principale et la paroi interne latérale soit faible ou nul, afin d'assurer des échanges thermiques satisfaisants entre ces deux composants du conteneur.In addition, the main structure is positioned in the cavity of the packaging so that the clearance between the main structure and the lateral internal wall is low or zero, in order to ensure satisfactory heat exchanges between these two components of the container.
Lors de la conception de tels conteneurs, il est nécessaire de prendre en compte des impératifs techniques dictés par les exigences réglementaires de sûreté pour le stockage/transport de matières nucléaires .When designing such containers, it is necessary to take into account the technical requirements dictated by regulatory safety requirements for the storage / transport of nuclear materials.
Parmi les tests à subir pour satisfaire ces exigences réglementaires, on note différentes épreuves telles que celles dites « de chute libre », dont notamment la chute sur poinçon et la chute de 9 mètres, précédant celle dite « d'incendie ».Among the tests to undergo to meet these regulatory requirements, there are various tests such as those called "free fall", including in particular the fall on a punch and the fall from 9 meters, preceding that called "fire".
Pour satisfaire les exigences de sûreté/criticité, les empilements de couches constituant l'emballage du conteneur ont été l'objet de nombreuses études, notamment pour répondre aux besoins spécifiques des épreuves concernant la chute sur poinçon et la chute de 9 mètres, ces épreuves devant être passées dans un ordre tel qu'il procure le maximum de dommages . Notons à titre indicatif que l'épreuve de poinçonnement consiste à surélever le conteneur à un mètre au-dessus d'un poinçon cylindrique de quinze centimètres de diamètre, puis à le laisser tomber par gravité sur le poinçon. Pour réussir cette épreuve ainsi que celle de chute de neuf mètres, il s'agit de démontrer que la structure principale du conteneur, c'est-à-dire le panier dans lequel reposent les assemblages de combustible nucléaire, ne subit aucune déformation. Dans les conteneurs connus de l'art antérieur, ces différentes exigences ont jusqu'à présent toujours été traduites par la nécessité de concevoir un emballage dont la/les couches d'extrémité intérieure en contact avec la structure principale, à savoir la paroi interne et plus particulièrement la paroi interne latérale définissant la cavité, ne se déformait pas suite à la réalisation des diverses épreuves, et plus spécifiquement suite à l'épreuve de poinçonnement . Par ailleurs, il est à noter que lors de la conception de tels conteneurs, des contraintes économiques sont également prises en compte. En effet, ce type de contraintes vise à accroître la charge utile d'un conteneur dont la masse maximale, 'lorsqu'il est chargé de ses- assemblages de combustible, est' limitée par les contraintes d'exploitation. L'objectif consiste par conséquent à proposer des solutions techniques permettant d'alléger au maximum l'emballage, tout en satisfaisant les contraintes réglementaires de sûreté.To meet safety / criticality requirements, the stacks of layers making up the container packaging have been the subject of numerous studies, in particular to meet the needs specific to the tests concerning the fall on a punch and the fall from 9 meters, these tests must be passed in an order such that it provides the maximum damage. As an indication, the punching test consists in raising the container one meter above a cylindrical punch fifteen centimeters in diameter, then dropping it by gravity on the punch. To pass this test as well as that of falling from nine meters, it is necessary to demonstrate that the main structure of the container, that is to say the basket in which the nuclear fuel assemblies rest, does not undergo any deformation. In the containers known from the prior art, these various requirements have hitherto always been translated by the need to design a package whose inner end layer (s) in contact with the main structure, namely the inner wall and more particularly the lateral internal wall defining the cavity, did not deform following the completion of the various tests, and more specifically following the punching test. Furthermore, it should be noted that when designing such containers, economic constraints are also taken into account. In fact, this type of constraint aims to increase the payload of a container whose maximum mass, ' when it is loaded with its fuel assemblies, is ' limited by operational constraints. The goal is consequently to propose technical solutions making it possible to lighten the packaging as much as possible, while satisfying regulatory safety constraints.
A ce titre, il est précisé que lorsqu'il s'agit de transporter des assemblages de combustible irradiés, l'épreuve de poinçonnement ne traduit aucune difficulté de conception, en raison de l'épaisseur importante de la face latérale de l'emballage, nécessaire au respect des critères de radioprotection. Un conteneur conçu pour le transport d'assemblages de combustible irradiés est décrit dans le document US-A-4 800 283. Il présente en effet une face latérale en acier de 30 cm d'épaisseur, engendrant par conséquent une masse excessivement élevée, et rendant ainsi ce type de conteneur totalement incompatible avec les contraintes économiques citées précédemment, rencontrées lors de la conception de conteneurs destinés au stockage/transport de matières radioactives non irradiées. Plusieurs solutions ont alors été proposées pour tenter de remplir l'ensemble des exigences techniques et économiques requises .As such, it is specified that when it comes to transporting irradiated fuel assemblies, the punching test does not reflect any design difficulty, due to the significant thickness of the lateral face of the packaging, necessary to meet the radiation protection criteria. A container designed for the transport of irradiated fuel assemblies is described in document US-A-4,800,283. It indeed has a steel side face 30 cm thick, consequently generating an excessively high mass, and thus making this type of container totally incompatible with the economic constraints mentioned above, encountered during the design of containers intended for the storage / transport of non-irradiated radioactive materials. Several solutions were then proposed in an attempt to fulfill all of the technical and economic requirements required.
Il a tout d'abord été proposé de concevoir des emballages multi-couches, chacune de ces couches étant destinée à contribuer à l'obtention d'un emballage assurant la préservation de la structure principale.It was first proposed to design multi-layer packaging, each of these layers being intended to contribute to obtaining a packaging ensuring the preservation of the main structure.
Parmi ces emballages multi-couches, on connaît tout d'abord des empilements à blindage anti- poinçon comprenant trois éléments superposés les uns sur les autres. Pour réaliser de tels empilements, les éléments sont positionnés de manière à ce qu'une plaque externe et une plaque interne en acier prennent en sandwich une couche anti-feu, cette dernière étant constituée d'un matériau à faible contrainte d'écrasement permettant d'absorber l'énergie de chute.Among these multi-layer packaging, there are first known stacks with anti-punch armor comprising three elements superimposed on each other. To achieve such stacks, the elements are positioned so that an external plate and an internal steel plate sandwich a fire-resistant layer, the latter being made of a material with low crushing stress making it possible to absorb the falling energy .
Néanmoins, lors de la réalisation de l'épreuve de poinçonnement, il a été observé que les plaques externe et interne en acier étaient respectivement perforée et déformée par le poinçon, ce qui provoquait directement une déformation de la structure principale en contact avec la plaque interne. Par ailleurs, la perforation de la plaque externe ne permettant^ plus,.de. conserver la,..coμche..intermédiai.r.e^d.e^ manière confinée et la tenue au feu de l'empilement devenant alors trop critique, cette solution a été jugée peu satisfaisante au regard des exigences réglementaires en vigueur.However, when carrying out the punching test, it was observed that the external and internal steel plates were respectively perforated and deformed by the punch, which directly caused a deformation of the main structure in contact with the internal plate. . Furthermore, the perforation of the external plate does not allow ^ more, .de. preserve,. .coμche . .intermediate . re ^ ^ confined to fashion and the fire resistance of the stack then becoming too critical, this solution was deemed unsatisfactory with regard to regulatory requirements.
Pour faire face à ce problème, un autre type d'empilement à blindage anti-poinçon a été proposé, intégrant cinq éléments superposés les uns sur les autres. Ce type de paroi est en outre décrit- dans le document FR-A-2 790 589.;To deal with this problem, another type of stack with anti-punching shielding has been proposed, integrating five elements superimposed on each other. This type of wall is further described in document FR-A-2 790 589 .;
Parmi ces éléments, on note tout d'abord une plaque externe rigide en acier, directement en contact avec une couche d'amortissement apte à absorber les agressions provoquées par un poinçon. Une plaque intermédiaire, en acier ou en matériau composite, est placée sous la couche d'amortissement, et est en contact inférieur avec une. couche déformable en compression, . à faible contrainte d'écrasement et pouvant présenter des propriétés anti-feu. Enfin,- le cinquième et dernier élément" de l'empilement de protection est constitué par une plaque interne rigide en acier, à haute résistance mécanique.Among these elements, there is first of all a rigid external steel plate, directly in contact with a damping layer capable of absorbing the aggressions caused by a punch. An intermediate plate, of steel or composite material, is placed under the damping layer, and is in lower contact with one. deformable layer in compression,. with low crushing stress and which may have fire-fighting properties. Finally, - the fifth and last element "of the protective stack consists of a rigid internal steel plate with high mechanical resistance.
De la même manière que précédemment, il a 5 été remarqué que l'empilement de cinq couches proposé ne permettait pas au conteneur de satisfaire les critères réglementaires, notamment à cause de la déformation de la plaque interne rigide, susceptible d'engendrer une déformation de la structure principale 0 du conteneur, en contact direct avec la paroi interne latérale de cette plaque interne rigide.In the same manner as previously, it has been noted that the proposed stacking of five layers does not allow the container to meet the regulatory criteria, in particular because of the deformation of the rigid internal plate, likely to cause deformation of the main structure 0 of the container, in direct contact with the lateral internal wall of this rigid internal plate.
Pour remédier à ce problème, il a donc été proposé, pour les deux types d'empilement présentés, de surdimensionner les plaques intégrées. 5 Cependant, il s'est avéré que les dimensions nécessaires à appliquer aux plaques pour réussir l'épreuve de poinçonnement n'étaient pas toujours compatibles avec l'exigence d'une masse maximum à respecter pour le conteneur, cette limitation 0 de masse étant imposée par les contraintes d' exploitation.To remedy this problem, it has therefore been proposed, for the two types of stacking presented, to oversize the integrated plates. 5 However, it turned out that the dimensions necessary to apply to the plates to pass the punching test were not always compatible with the requirement of a maximum mass to be observed for the container, this limitation 0 of mass being imposed by operational constraints.
Ainsi, les concepteurs de tels conteneurs sont donc constamment confrontés à un compromis entre une masse totale restreinte des différentes plaquesThus, the designers of such containers are constantly confronted with a compromise between a limited total mass of the different plates
25 constituant les éléments de l'emballage, et une résistance mécanique suffisante de ces éléments pour que la paroi interne latérale de cet emballage ne se déforme pas, toujours dans le but de réussir l'ensemble des tests pratiqués lors des épreuves réglementaires de25 constituting the elements of the packaging, and a sufficient mechanical resistance of these elements so that the lateral internal wall of this packaging does not deform, always with the aim of passing all the tests carried out during the regulatory tests of
3.0 sûreté relatives au transport/stockage de matières nucléaires . EXPOSÉ DE L'INVENTION3 . 0 safety related to the transport / storage of nuclear materials. STATEMENT OF THE INVENTION
L'invention a donc pour but de proposer un conteneur pour le stockage/transport de matières radioactives non irradiées telles que des assemblages de combustible nucléaire, le conteneur comprenant une structure principale et un emballage comportant une paroi interne latérale définissant une cavité à l'intérieur de laquelle est apte à être logée la structure principale, le conteneur remédiant au moins partiellement aux inconvénients mentionnés ci-dessus relatifs aux réalisations de l'art antérieur.The object of the invention is therefore to propose a container for the storage / transport of non-irradiated radioactive materials such as nuclear fuel assemblies, the container comprising a main structure and a package comprising a lateral internal wall defining a cavity inside. which is able to accommodate the main structure, the container at least partially overcoming the drawbacks mentioned above relating to the embodiments of the prior art.
Plus précisément, le but de l'invention est de présenter un conteneur dont la conception permet de satisfaire les exigences réglementaires de sûreté relatives au transport/stockage de matières nucléaires, tout en disposant d'une masse totale largement affaiblie par rapport aux conteneurs de l'art antérieur, afin de respecter des contraintes d'exploitation toujours plus importantes. Pour ce faire, l'invention a pour objet un conteneur pour le stockage/transport de matières radioactives non irradiées telles que des assemblages de combustible nucléaire, le conteneur comprenant une structure principale et un emballage comportant une paroi interne latérale définissant une cavité à l'intérieur de laquelle est apte à être logée la structure principale, cette dernière définissant une pluralité de logements chacun apte à recevoir au moins un assemblage de combustible. Selon l'invention, le conteneur comporte en outre des moyens d'espacement de la structure principale par rapport à' l'emballage, les moyens d'espacement étant aptes à éviter tout contact direct entre la paroi interne latérale et la structure principale, de façon à autoriser une déformation ponctuelle de cette paroi interne latérale de l'emballage lors d'une épreuve de poinçonnement.More specifically, the object of the invention is to present a container whose design makes it possible to meet regulatory safety requirements relating to the transport / storage of nuclear materials, while having a total mass which is greatly weakened compared to the containers of the prior art, in order to comply with ever greater operating constraints. To do this, the subject of the invention is a container for the storage / transport of non-irradiated radioactive materials such as nuclear fuel assemblies, the container comprising a main structure and a package comprising a lateral internal wall defining a cavity at the inside of which the main structure is capable of being housed, the latter defining a plurality of housings each capable of receiving at least one fuel assembly. According to the invention, the container further comprises spacer means of the main structure with respect to 'packaging, spacing means being able to avoid any direct contact between the lateral internal wall and the main structure, so as to allow a punctual deformation of this lateral internal wall of the packaging during a punching test.
Avantageusement, la conception spécifique du conteneur selon l'invention résulte d'une approche totalement différente de l'approche classique antérieurement pratiquée pour concevoir de tels conteneurs. En effet, la condition principale pour satisfaire les exigences réglementaires de sûreté relatives au transport/stockage de matières nucléaires étant de démontrer que la structure principale contenant les assemblages de combustible n'est pas endommagée suite aux différentes épreuves de chute du conteneur, cette contrainte technique a toujours été interprétée comme une nécessité de préserver intacte la paroi interne latérale de l'emballage, suite à la mise en œuvre de ces tests divers . Cependant, l'invention a été réalisée en dérogeant à cette pratique classique, en prévoyant un emballage dont la paroi interne latérale est susceptible de se déformer de manière ponctuelle suite à des sollicitations mécaniques pratiquées extérieurement sur l'emballage, telles que celles exercées par un poinçon lors de l'épreuve de poinçonnement. Pour qu'une déformation de la paroi interne latérale n'endommage pas la structure principale du conteneur, contrairement à l'ensemble des conteneurs de l'art antérieur, aucun contact direct n'a été prévu entre cette paroi interne latérale et la structure principale, de sorte que la transmission de la déformation ne peut s'effectuer.Advantageously, the specific design of the container according to the invention results from an approach completely different from the conventional approach previously practiced for designing such containers. Indeed, the main condition for satisfying the regulatory safety requirements relating to the transport / storage of nuclear materials being to demonstrate that the main structure containing the fuel assemblies is not damaged following the various drop tests of the container, this technical constraint has always been interpreted as a need to preserve the lateral internal wall of the packaging intact, following the implementation of these various tests. However, the invention has been made by departing from this conventional practice, by providing a package whose lateral internal wall is capable of deforming in a punctual manner following mechanical stresses exerted on the packaging externally, such as those exerted by a punch during the punching test. So that a deformation of the lateral internal wall does not damage the main structure of the container, unlike all the containers of the prior art, no direct contact has been provided between this lateral internal wall and the main structure, so that the deformation cannot be transmitted.
Ainsi, la structure principale du conteneur contenant les assemblages de combustible est apte à rester intacte suite à la réalisation des différentes épreuves de chute, malgré la déformation de la paroi interne latérale de l'emballage occasionnée. Par conséquent, la conception de cet emballage peut alors être considérablement simplifiée. En effet, la conception spécifique retenue pour le conteneur selon l'invention autorisant que la paroi interne latérale de l'emballage soit déformée lors de l'épreuve de chute sur poinçon, cet emballage ne nécessite plus d'être réalisé à l'aide d'empilements complexes de couches surdimensionnées, et peut donc subir de larges simplifications ainsi qu'une réduction non négligeable de masse et d'épaisseur par rapport aux emballages antérieurement proposés.Thus, the main structure of the container containing the fuel assemblies is able to remain intact following the completion of the various drop tests, despite the deformation of the lateral internal wall of the packaging caused. Consequently, the design of this package can then be considerably simplified. Indeed, the specific design retained for the container according to the invention allowing the lateral internal wall of the packaging to be deformed during the drop test on punch, this packaging no longer needs to be produced using 'complex stacks of oversized layers, and can therefore undergo large simplifications as well as a significant reduction in mass and thickness compared to previously offered packaging.
Les avantages susmentionnés se traduisent alors directement par une réduction des coûts de production des conteneurs, ainsi que par la possibilité d'augmenter le nombre d'assemblages de combustible nucléaire pouvant être contenus dans chacun de ces conteneurs, tout en satisfaisant les contraintes d'exploitation existantes.The aforementioned advantages then translate directly into a reduction in the production costs of the containers, as well as the possibility of increasing the number of nuclear fuel assemblies that can be contained in each of these containers, while satisfying the operating constraints. existing.
Selon un premier mode de réalisation préféré de la présente invention, les moyens d'espacement de la structure principale par rapport à l'emballage sont prévus entre la structure principale et la paroi interne latérale de l'emballage, les moyens d'espacement disposant d'une fonction de fusible mécanique afin de se déformer lors d'une déformation ponctuelle de la paroi interne latérale de l'emballage, survenant suite à l'épreuve de poinçonnement. En revanche, il est indiqué que les moyens d'espacement sont également conçus afin de résister, et donc afin de ne pas se déformer, suite aux sollicitations mécaniques rencontrées lors des chutes de 9 mètres .According to a first preferred embodiment of the present invention, the means for spacing the main structure relative to the packaging are provided between the main structure and the lateral internal wall of the packaging, the spacing means having '' a fuse function mechanical in order to deform during a punctual deformation of the lateral internal wall of the packaging, occurring following the punching test. On the other hand, it is indicated that the spacing means are also designed to resist, and therefore not to deform, following the mechanical stresses encountered during falls from 9 meters.
Dans ce mode de réalisation préféré, l'espace prévu entre la paroi interne latérale de l'emballage et la structure principale est au moins partiellement comblé par les moyens d'espacement, de manière à assurer une fonction supplémentaire de transfert thermique entre ces éléments. Notons que cette fonction est rendue possible en raison du jeu faible ou nul existant entre d'une part les moyens de d'espacement et la structure principale, et d'autre part la paroi interne latérale de l'emballage et ces mêmes moyens d'espacement.In this preferred embodiment, the space provided between the lateral internal wall of the packaging and the main structure is at least partially filled by the spacing means, so as to provide an additional function of heat transfer between these elements. Note that this function is made possible due to the small or zero clearance existing between on the one hand the spacing means and the main structure, and on the other hand the lateral internal wall of the packaging and these same means of spacing.
Les moyens d'espacement sont avantageusement conçus afin de remplir un rôle de fusible mécanique lors d'une chute sur poinçon, celle- ci provoquant généralement une déformation ponctuelle de la paroi interne latérale de l'emballage. Ainsi, les moyens d'espacement sont directement détériorés sous l'effet de la déformation de la paroi interne latérale, sans transmettre cette déformation à la structure principale du conteneur, qui reste totalement intacte.The spacing means are advantageously designed to fulfill the role of a mechanical fuse during a fall on a punch, the latter generally causing a punctual deformation of the lateral internal wall of the packaging. Thus, the spacing means are directly damaged under the effect of the deformation of the lateral internal wall, without transmitting this deformation to the main structure of the container, which remains completely intact.
Par ailleurs, les moyens d'espacement sont également conçus pour ne pas se déformer lors des épreuves de chute de 9 mètres, plus particulièrement lors des chutes horizontales, sous l'inertie de la structure principale chargée des assemblages de combustible. Ainsi, les moyens d'espacement sont conçus afin de pouvoir être en mesure de remplir pleinement les fonctions de fusible mécanique, même lorsque les chutes sur poinçon sont réalisées à l'issue des chutes de 9 mètres .In addition, the spacing means are also designed not to deform during the 9 meter drop tests, more particularly during horizontal falls, under the inertia of the main structure responsible for fuel assemblies. Thus, the spacing means are designed so as to be able to fully fulfill the functions of a mechanical fuse, even when the falls on a punch are made after the falls from 9 meters.
Préférentiellement , les moyens d'espacement sont composés d'une pluralité de secteurs déformables répartis autour de la structure principale du conteneur, ces secteurs s'étendant sur toute la longueur ou seulement sur une partie de la longueur de la structure principale de l'emballage, ou étant empilés les uns sur les autres selon une direction parallèle à un axe principal longitudinal du conteneur. Notons que dans une autre variante, les secteurs déformables sont disposés les uns à côté des autres de façon à former des bandes encerclant la structure principale.Preferably, the spacing means are composed of a plurality of deformable sectors distributed around the main structure of the container, these sectors extending over the entire length or only over part of the length of the main structure of the packaging. , or being stacked on top of each other in a direction parallel to a longitudinal main axis of the container. Note that in another variant, the deformable sectors are arranged next to each other so as to form strips encircling the main structure.
Dans ce premier mode de réalisation préféré, on peut indifféremment prévoir que les secteurs déformables soient réalisés dans un matériau à faible contrainte d'écrasement tel que du bois, de la mousse plastique ou du nid-d'abeilles confiné entre deux tôles métalliques, ou encore d'éléments métalliques prenant la forme de deux tôles concentriques séparées par des renforts.In this first preferred embodiment, it is equally possible to provide that the deformable sectors are made of a material with low crushing stress such as wood, plastic foam or honeycomb confined between two metal sheets, or still metallic elements taking the form of two concentric sheets separated by reinforcements.
Dans ce derniers cas, les éléments métalliques sont réalisés de préférence en aluminium ou dans l'un de ses alliages. De façon préférée, les secteurs déformables sont fixés sur la structure principale de l'emballage, et recouvrent- totalement ou uniquement partiellement la structure principale du conteneur.In the latter case, the metal elements are preferably made of aluminum or one of its alloys. Preferably, the deformable sectors are fixed to the main structure of the packaging, and completely or only partially cover the main structure of the container.
Selon un second mode de réalisation préféré de la présente invention, les moyens d'espacement de la structure principale par rapport à l'emballage sont prévus sur un couvercle et/ou un fond fixe de l'emballage, la paroi interne latérale de l'emballage et la structure principale étant séparées par un espace vide. Cette solution reste très avantageuse dans la mesure où elle permet d'obtenir un conteneur relativement léger, en raison de l'absence de matière entre la paroi interne latérale de l'emballage et la structure principale. Préférentiellement, pour les deux modes de réalisation préférés mentionnés ci-dessus, la structure principale du conteneur dispose d'une forme sensiblement cylindrique de section circulaire, et la paroi interne latérale de 1 ' emballage et la structure principale sont séparées par un espace de forme sensiblement annulaire.According to a second preferred embodiment of the present invention, the means for spacing the main structure relative to the packaging are provided on a cover and / or a fixed bottom of the packaging, the lateral internal wall of the packaging and the main structure being separated by an empty space. This solution remains very advantageous insofar as it makes it possible to obtain a relatively light container, due to the absence of material between the lateral internal wall of the packaging and the main structure. Preferably, for the two preferred embodiments mentioned above, the main structure of the container has a substantially cylindrical shape of circular section, and the inner side wall of the package and the main structure are separated by a form space. substantially annular.
D'autres avantages et caractéristiques de l'invention apparaîtront dans la description détaillée non limitative ci-dessous.Other advantages and characteristics of the invention will appear in the detailed non-limiting description below.
BRÈVE DESCRIPTION DES DESSINSBRIEF DESCRIPTION OF THE DRAWINGS
Cette description sera faite au regard des dessins annexés parmi lesquels ; la figure 1 représente une vue en perspective d'un conteneur ' pour le stockage/transport de matières nucléaires non irradiées, selon un premier mode de . éalisation préféré de la présente invention ; - la figure 2 représente une vue partielle en coupe du conteneur représenté sur la figure 1, selon un plan perpendiculaire à l'axe principal longitudinal de ce conteneur ; la figure 3 représente une vue en perspective d'un secteur dêformable tel que celui utilisé dans les moyens d'espacement du conteneur représenté sur la figure 1 ; la figure 4 représente une vue schématique en perspective d'une structure principale du conteneur représenté sur la figure 1, munie d'une pluralité de secteurs déformables ; la figure 5 représente une vue schématique en coupe expliquant le comportement d'un conteneur tel que celui représenté sur la figure 1, suite à l'exécution d'une épreuve de poinçonnement ;This description will be made with reference to the accompanying drawings, among which; Figure 1 shows a perspective view of a container ' for the storage / transport of non-irradiated nuclear material, according to a first mode. preferred embodiment of the present invention; - Figure 2 shows a partial sectional view of the container shown in Figure 1, along a plane perpendicular to the main longitudinal axis of this container; 3 shows a perspective view of a deformable sector such as that used in the spacing means of the container shown in Figure 1; 4 shows a schematic perspective view of a main structure of the container shown in Figure 1, provided with a plurality of deformable sectors; 5 shows a schematic sectional view explaining the behavior of a container such as that shown in Figure 1, following the execution of a punching test;
- la figure 6 représente une vue partielle en perspective d'un conteneur pour le stockage/transport de matières nucléaires non irradiées, selon un second mode de réalisation préféré de la présente invention ; et- Figure 6 shows a partial perspective view of a container for the storage / transport of non-irradiated nuclear material, according to a second preferred embodiment of the present invention; and
- la figure 7 représente une vue partielle en coupe du conteneur représenté sur la figure 6, selon un plan perpendiculaire à l'axe principal longitudinal de ce conteneur.- Figure 7 shows a partial sectional view of the container shown in Figure 6, along a plane perpendicular to the main longitudinal axis of this container.
EXPOSÉ DETAILLE DE MODES DE RÉALISATION PRÉFÉRÉSDETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
En référence aux figures 1 et 2 , on voit un conteneur 1 pour le stockage/transport de matières radioactives non irradiées telles que des assemblages de combustible nucléaire frais (non représentés)', selon un premier mode de réalisation préféré de la présente invention.Referring to Figures 1 and 2, we see a container 1 for the storage / transport of non-irradiated radioactive material such as fresh nuclear fuel assemblies (not shown) ' , according to a first preferred embodiment of the present invention.
Le conteneur 1 comprend un emballage 2 ainsi qu'une structure principale 4 du type panier, apte à être logé à l'intérieur de l'emballage 2 du conteneur 1.The container 1 comprises a packaging 2 as well as a main structure 4 of the basket type, capable of being housed inside the packaging 2 of the container 1.
L'emballage 2 est constitué d'une face latérale 6 de forme sensiblement annulaire, d'un fond fixe 8, d'un couvercle 10, et de deux capots de protection amovibles 12 et 14 agencés aux extrémités de l'emballage 2.The package 2 consists of a side face 6 of substantially annular shape, a fixed bottom 8, a cover 10, and two removable protective covers 12 and 14 arranged at the ends of the package 2.
Notons que dans ce premier mode de réalisation préféré de la présente invention, la face latérale 6 de l'emballage 2 est unique, mais pourrait bien entendu être composée de plusieurs éléments rapportés les uns aux autres, sans sortir du cadre de 1' invention.Note that in this first preferred embodiment of the present invention, the side face 6 of the package 2 is unique, but could of course be composed of several elements attached to each other, without departing from the scope of the invention.
Cette face latérale 6 est composée d'une virole interne 16 et d'une virole externe 18 centrées sur un axe principal longitudinal 19 du conteneur 1, ces viroles 16 et 18 étant espacées et maintenues l'une par rapport à l'autre par l'intermédiaire de raidisseurs 20, qui ont également pour fonction de conduire la chaleur au travers d'une protection neutronique 22, également située entre les deux viroles 16 et 18.This lateral face 6 is composed of an internal ferrule 16 and an external ferrule 18 centered on a main longitudinal axis 19 of the container 1, these ferrules 16 and 18 being spaced and held relative to one another by the 'through stiffeners 20, which also have the function of conducting heat through a neutron protection 22, also located between the two ferrules 16 and 18.
La virole interne 16 de la face latérale 6 de l'emballage 2 dispose d'une paroi interne latérale 24, définissant une cavité à l'intérieur de laquelle est apte à être logée la structure principale 4 du conteneur 1. Comme on peut le voir sur les figures 1 etThe internal ferrule 16 of the lateral face 6 of the package 2 has a lateral internal wall 24, defining a cavity inside which is able to be housed the main structure 4 of the container 1. As can be seen in Figures 1 and
2, la structure principale 4 reposant dans la cavité cylindrique définie par la paroi interne latérale 24 comprend une pluralité de logements 26, chacun apte à recevoir un assemblage de combustible nucléaire frais.2, the main structure 4 resting in the cylindrical cavity defined by the lateral internal wall 24 comprises a plurality of housings 26, each capable of receiving an assembly of fresh nuclear fuel.
La structure principale 4 du conteneur 1 présente préférentiellement une forme sensiblement cylindrique de section circulaire, et peut être réalisée selon les techniques classiques connues. A cet égard, il est à noter que dans le mode de réalisation représenté, la structure 4 est obtenue par un empilement de disques 28 selon l'axe principal longitudinal 19 du conteneur 1. Une pluralité d'orifices pratiquée sur chacun des disques 28 permet ainsi de définir les logements 26, dans lesquels sont susceptibles d'être introduits les assemblages de combustible nucléaire.The main structure 4 of the container 1 preferably has a substantially cylindrical shape of circular section, and can be produced according to known conventional techniques. In this regard, it should be noted that in the embodiment shown, the structure 4 is obtained by a stack of discs 28 along the longitudinal main axis 19 of the container 1. A plurality of orifices made on each of the discs 28 allows thus defining the housings 26, into which the nuclear fuel assemblies may be introduced.
Par ailleurs, le conteneur 1 comporte également des moyens d'espacement de la structure principale 4 par rapport à l'emballage 2, les moyens d'espacement étant aptes à éviter tout contact direct entre la paroi interne latérale 24 et la structure principale 4, de façon à autoriser une déformation ponctuelle de cette paroi interne latérale 24 de l'emballage 2 lors d'une épreuve de poinçonnement.'Furthermore, the container 1 also comprises means for spacing the main structure 4 relative to the packaging 2, the spacing means being able to avoid any direct contact between the lateral internal wall 24 and the main structure 4, so as to allow a specific deformation of this lateral internal wall 24 of the package 2 during a punching test. '
Dans ce premier mode de réalisation préféré de la présente invention, les moyens d'espacement 30 sont prévus entre la structure principale 4 et la paroi interne latérale 24 de l'emballage 2, afin d'assurer notamment une fonction de transfert thermique entre les éléments 2 et 4. Comme on peut l'apercevoir sur la figure 2, la structure principale 4 dispose en effet d'un diamètre extérieur inférieur au diamètre de la paroi interne latérale 24, cette conception spécifique du conteneur 1 entraînant la formation d'un espace de forme sensiblement annulaire, à l'intérieur duquel peuvent être logés les moyens d'espacement 30. La disposition particulière des moyens d'espacement 30 peut alors permettre à ces moyens de remplir une fonction de fusible mécanique autorisant des déformations ponctuelles de la paroi interne latérale 24 de l'emballage 2. Cette fonction sera plus largement exposée ci-dessous.In this first preferred embodiment of the present invention, the spacing means 30 are provided between the main structure 4 and the lateral internal wall 24 of the package 2, in order to ensure in particular a heat transfer function between the elements 2 and 4. As can be seen in FIG. 2, the main structure 4 indeed has an outside diameter smaller than the diameter of the lateral internal wall 24, this specific design of the container 1 resulting in the formation of a space of substantially annular shape. , inside which the spacing means 30 can be accommodated. The particular arrangement of the spacing means 30 can then allow these means to fulfill a mechanical fuse function allowing punctual deformations of the internal lateral wall 24 of the packaging 2. This function will be more fully explained below.
En référence aux figures 2 à , on peut voir que les moyens d'espacement 30 sont constitués d'une pluralité de secteurs déformables 32, répartis autour de la structure principale 4, sur laquelle ils sont préférablement assemblés par vissage.Referring to Figures 2 to, it can be seen that the spacing means 30 consist of a plurality of deformable sectors 32, distributed around the main structure 4, on which they are preferably assembled by screwing.
Plus spécifiquement en référence à la figure 4 destinée à mieux comprendre les différentes possibilités d'agencement des secteurs 32, ces derniers peuvent tout d'abord s'étendre sur sensiblement toute la longueur de la structure principale 4, comme le montre la bande 34. Par ailleurs, les secteurs déformables 32 peuvent aussi être empilés les uns sur les autres selon une direction parallèle à l'axe principal longitudinal 19 du conteneur 1, comme le montre la bande 36.More specifically with reference to FIG. 4 intended to better understand the different possibilities of arrangement of the sectors 32, these can first of all extend over substantially the entire length of the main structure 4, as shown by the strip 34. Furthermore, the deformable sectors 32 can also be stacked on top of each other in a direction parallel to the main longitudinal axis 19 of the container 1, as shown by the strip 36.
D'autre part, outre la possibilité de prévoir des bandes 34,36 de secteurs déformables 32 sur sensiblement toute la longueur de la structure principale 4, il est également possible de réaliser des bandes 38 constituées d'un ou plusieurs secteurs 32, et ne recouvrant que partiellement la longueur de cette structure principale 4. Enfin, les secteurs déformables 32 peuvent aussi être agencés les uns à côté des autres de façon à former des bandes annulaires (non représentées) encerclant la structure principale 4 et réparties sur toute la longueur de cette structure 4 ou uniquement aux deux extrémités de celle-ci.On the other hand, in addition to the possibility of providing strips 34, 36 of deformable sectors 32 over substantially the entire length of the structure main 4, it is also possible to produce bands 38 consisting of one or more sectors 32, and only partially covering the length of this main structure 4. Finally, the deformable sectors 32 can also be arranged one beside the other so as to form annular bands (not shown) encircling the main structure 4 and distributed over the entire length of this structure 4 or only at the two ends thereof.
Ainsi, comme on peut le constater, la diversité de dispositions des secteurs déformables 32 sur la structure principale 4 est très importante, et peut conduire à un recouvrement total ou partiel de la structure principale 4 du conteneur 1.Thus, as can be seen, the diversity of arrangements of the deformable sectors 32 on the main structure 4 is very large, and can lead to total or partial covering of the main structure 4 of the container 1.
A ce titre, l'emplacement des secteurs 32 sur la structure 4 peut par conséquent être judicieusement choisi, afin de répondre au mieux aux contraintes de masse et aux contraintes mécaniques à respecter par le conteneur 1.As such, the location of the sectors 32 on the structure 4 can therefore be judiciously chosen, in order to best respond to the mass constraints and the mechanical constraints to be met by the container 1.
Selon un exemple non limitatif donné uniquement à titre illustratif, le diamètre extérieur de la face latérale 6 de l'emballage 2 est de l'ordre 1400 mm pour un diamètre intérieur de l'ordre 1000 mm. De plus, l'espace annulaire prévu entre la paroi interne latérale 24 et la structure principale 4, tout comme les secteurs déformables 32 en contact avec ces deux éléments 4 et 24, dispose d'une épaisseur d'environ 30 à 35 mm. Dans le premier mode de réalisation préféré de l'invention représenté sur les figures 1 à 4, chaque secteur déformable 32 est constitué d'un élément métallique réalisé préférentiellement en aluminium ou dans l'un de ses alliages, cet élément prenant la forme de deux tôles concentriques 40 et 42 d'axe identique à l'axe principal longitudinal 19 du conteneur 1, les tôles 40 et 42 étant séparées par des renforts 44 (figure 3) . Préférentiellement, les éléments métalliques constituant les secteurs déformables 32 sont extrudés, mais pourraient également être réalisés par mécano-soudage ou toute autre technique classique, sans sortir du cadre de l'invention.According to a nonlimiting example given only by way of illustration, the outside diameter of the lateral face 6 of the package 2 is around 1400 mm for an inside diameter around 1000 mm. In addition, the annular space provided between the lateral internal wall 24 and the main structure 4, like the deformable sectors 32 in contact with these two elements 4 and 24, has a thickness of approximately 30 to 35 mm. In the first preferred embodiment of the invention shown in Figures 1 to 4, each deformable sector 32 consists of a metallic element preferably made of aluminum or one of its alloys, this element taking the form of two concentric sheets 40 and 42 of identical axis to the main longitudinal axis 19 of the container 1, the sheets 40 and 42 being separated by reinforcements 44 (Figure 3). Preferably, the metal elements constituting the deformable sectors 32 are extruded, but could also be produced by mechanical welding or any other conventional technique, without departing from the scope of the invention.
Notons que les parties en forme de tôles 40 et 42 sont respectivement en contact avec la structure principale 4, et la paroi interne latérale 24. De plus, toujours de façon préférentielle, les éléments 40, 42 et 44 disposent chacun d'une épaisseur inférieure à environ la moitié de l'épaisseur de la virole interne 16.Note that the sheet-like parts 40 and 42 are respectively in contact with the main structure 4, and the lateral internal wall 24. In addition, still preferably, the elements 40, 42 and 44 each have a lower thickness. about half the thickness of the inner shell 16.
Les renforts 44 s'étendent chacun sur toute la longueur des parties en forme de tôles 40 et 42, et sont inclinés par rapport à un rayon de cercle concentrique aux parties en forme de tôles 40 et 42. De plus, les renforts 44 sont agencés de manière à ce que deux renforts 44 successifs soient inclinés selon un sens opposé, de manière à être en opposition de phase. A titre d'exemple non limitatif, l'angle d'inclinaison des renforts peut avoisiner ± 20°.The reinforcements 44 each extend over the entire length of the sheet-shaped parts 40 and 42, and are inclined with respect to a radius of circle concentric with the sheet-shaped parts 40 and 42. In addition, the reinforcements 44 are arranged so that two successive reinforcements 44 are inclined in an opposite direction, so as to be in phase opposition. By way of nonlimiting example, the angle of inclination of the reinforcements can be around ± 20 °.
Bien entendu, les secteurs déformables 32 peuvent prendre toute autre forme et être constitués à l'aide d'autres matériaux, dans la mesure où ceux-ci sont aptes à espacer la structure principale 4 de l'emballage 2, . et susceptibles de remplir un rôle de fusible mécanique décrit ci-dessous. Toujours à titre d'exemple non limitatif, les secteurs déformables 32 peuvent alors être réalisés dans un matériau à faible contrainte d'écrasement comme la mousse plastique, le nid-d'abeilles, ou le bois tel que du balsa, confiné ou non entre deux tôles métalliques.Of course, the deformable sectors 32 can take any other form and be formed using other materials, insofar as these are capable of spacing the main structure 4 from packaging 2,. and likely to fulfill the role of mechanical fuse described below. Still by way of nonlimiting example, the deformable sectors 32 can then be made of a material with low crushing stress such as plastic foam, honeycomb, or wood such as balsa, confined or not between two metal sheets.
En référence à la figure 5, il va à présent être décrit le comportement mécanique du conteneur 1 lors d'une épreuve de poinçonnement, tel que celle opérée lors des épreuves réglementaires de sûreté relatives au transport/stockage de matières nucléaires. Notons que cette description va être effectuée pour des secteurs déformables 32 du type élément métallique représenté sur la figure 3. Cependant, il est précisé que le comportement du conteneur 1 reste similaire quel que soit le type de moyens d'espacement 30 interposés entre la structure principale 4 et la paroi interne latérale 24 de l'emballage 2, à condition que ces moyens 30 soient susceptibles de remplir une fonction de fusible mécanique entre les deux éléments 2 et 4.With reference to FIG. 5, a description will now be given of the mechanical behavior of the container 1 during a punching test, such as that carried out during regulatory safety tests relating to the transport / storage of nuclear materials. Note that this description will be made for deformable sectors 32 of the metal element type shown in FIG. 3. However, it is specified that the behavior of the container 1 remains similar regardless of the type of spacing means 30 interposed between the structure main 4 and the lateral internal wall 24 of the package 2, provided that these means 30 are capable of fulfilling a mechanical fuse function between the two elements 2 and 4.
Lorsque l'emballage 2 du conteneur 1 entre en contact avec un poinçon 46 d'environ 150 mm de diamètre, ce poinçon 46 provoque des sollicitations mécaniques locales importantes sur l'emballage 2, de sorte que la face latérale 6 se déforme sur toute son épaisseur dans une zone située en regard du poinçon 46. Notons que l'emballage 2 est préférentiellement conçu de manière à ce que suite à une telle épreuve de poinçonnement, la virole interne 16 de cet emballage 2 est déformée mais pas perforée. De cette façon, la virole interne 16 de l'emballage 2 se déforme en pénétrant dans l'espace annulaire d'axe 19 initialement prévu entre la paroi interne latérale 24 et la structure principale 4 du conteneur 1, cet espace annulaire étant occupé par les moyens d'espacement 30.When the packaging 2 of the container 1 comes into contact with a punch 46 of approximately 150 mm in diameter, this punch 46 causes significant local mechanical stresses on the packaging 2, so that the lateral face 6 is deformed over its whole thickness in an area located opposite the punch 46. Note that the packaging 2 is preferably designed so that following such a punching test, the internal shell 16 of this packaging 2 is deformed but not perforated. In this way, the internal shroud 16 of the packaging 2 is deformed by penetrating into the annular space of axis 19 initially provided between the internal lateral wall 24 and the main structure 4 of the container 1, this annular space being occupied by the spacing means 30.
Le ou les secteurs déformables 32 des moyens d'espacement 30 situés en regard de la déformation de la paroi interne latérale 24 jouent alors leur rôle de fusible mécanique en se dégradant directement suite à l'impact de la paroi interne latérale 24, sans transmettre la déformation à la structure principale 4 du conteneur 1. Il est par ailleurs indiqué que la déformation de la paroi interne latérale 24 s'opère sensiblement comme si aucun élément n'existait entre la structure 4 et cette paroi interne latérale 24. En effet, les secteurs 32 sont conçus afin que leur énergie de déformation soit négligeable devant l'énergie mise en jeu lors de la chute sur le poinçon 46, en grande partie absorbée par la déformation ponctuelle de la face latérale 6 de l'emballage 2.The deformable sector or sectors 32 of the spacing means 30 located opposite the deformation of the lateral internal wall 24 then play their role of mechanical fuse by degrading directly following the impact of the lateral internal wall 24, without transmitting the deformation to the main structure 4 of the container 1. It is also indicated that the deformation of the lateral internal wall 24 takes place as if no element existed between the structure 4 and this lateral internal wall 24. In fact, the sectors 32 are designed so that their deformation energy is negligible compared to the energy involved when falling on the punch 46, largely absorbed by the point deformation of the side face 6 of the package 2.
Dans le cas représenté sur la figure 5, la partie 42 du type tôle est déformée sous l'effet de la déformation de la paroi interne latérale 24. De plus, le/les renforts 44 situés à proximité de cette déformation sont également détériorés, toujours de manière à ce que la déformation de la paroi interne latérale 24 ne soit pas transmise à la structure principale 4 du conteneur 1. Les secteurs déformables 32 n'épousant pas nécessairement toute la surface de la paroi interne latérale 24, il est par conséquent possible de rencontrer des cas dans lesquels la déformation de cette paroi interne latérale 24 se situe dans une zone dépourvue de moyens d'espacement 30, et donc de secteurs déformables 32. La paroi interne latérale 24 se déforme alors tout simplement dans le vide de l'espace annulaire pratiqué entre les éléments 2 et 4, selon sensiblement la même amplitude que celle qui aurait été obtenue en présence de secteurs déformables 32, toujours en raison de la fonction principale de fusible mécanique de ces secteurs.In the case shown in FIG. 5, the sheet metal part 42 is deformed under the effect of the deformation of the lateral internal wall 24. In addition, the reinforcement 44 located near this deformation are also deteriorated, always so that the deformation of the lateral internal wall 24 is not transmitted to the main structure 4 of the container 1. The deformable sectors 32 do not necessarily follow the entire surface of the internal wall lateral 24, it is therefore possible to encounter cases in which the deformation of this lateral internal wall 24 is located in an area devoid of spacing means 30, and therefore of deformable sectors 32. The lateral internal wall 24 then deforms quite simply in the vacuum of the annular space formed between the elements 2 and 4, according to substantially the same amplitude as that which would have been obtained in the presence of deformable sectors 32, still due to the main function of mechanical fuse of these sectors.
Ainsi, les moyens d'espacement 30 du conteneur 1 autorisent une déformation ponctuelle de la paroi interne latérale 24, l'amplitude de cette déformation étant limitée par l'épaisseur initiale de l'espace présent entre la paroi interne latérale 24 et la structure principale 4, de sorte que cette paroi 24 ne viennent pas directement percuter la structure 4 du conteneur 1. Lors de la conception d'un tel conteneur 1, pour une structure donnée de l'emballage 2, l'épaisseur de l'espace annulaire pourra par exemple être fixée de façon à ce que la déformation maximale de la paroi interne latérale 24, provoquée par un poinçon 46 dans des conditions de sollicitations analogues à celles rencontrées lors des épreuves réglementaires, soit compatible avec cette épaisseur.Thus, the spacing means 30 of the container 1 allow a punctual deformation of the lateral internal wall 24, the amplitude of this deformation being limited by the initial thickness of the space present between the lateral internal wall 24 and the main structure. 4, so that this wall 24 does not directly strike the structure 4 of the container 1. When designing such a container 1, for a given structure of the packaging 2, the thickness of the annular space may for example be fixed so that the maximum deformation of the lateral internal wall 24, caused by a punch 46 under stress conditions similar to those encountered during regulatory tests, is compatible with this thickness.
Enfin, préférentiellement, les moyens d'espacement 30 sont également avantageusement conçus de façon à résister d'une manière globale aux sollicitations mécaniques dues à l'inertie importante de la structure principale 4 générée lors des chutes de 9 mètres, plus particulièrement lors des chutes horizontales, n'entraînant habituellement pas de déformation de la face latérale 6 de l'emballage 2.Finally, preferably, the spacing means 30 are also advantageously designed so as to generally resist mechanical stresses due to the significant inertia of the main structure 4 generated during falls of 9 meters, more particularly during horizontal falls, usually not causing deformation of the side face 6 of the package 2.
En référence aux figures 6 et 7, il est représenté partiellement un conteneur 100 pour le stockage/transport de matières radioactives non irradiées telles que des assemblages de combustible nucléaire frais (non représentés) , selon un second mode de réalisation préféré de la présente invention. Sur ces figures, les éléments portant les mêmes références numériques que celles attachées aux éléments représentés sur les figures 1 à 5, correspondent à des éléments identiques ou similaires.Referring to Figures 6 and 7, there is shown partially a container 100 for the storage / transport of non-irradiated radioactive material such as fresh nuclear fuel assemblies (not shown), according to a second preferred embodiment of the present invention. In these figures, the elements bearing the same numerical references as those attached to the elements represented in FIGS. 1 to 5, correspond to identical or similar elements.
Dans ce second mode de réalisation préféré de la présente invention, seuls les moyens d'espacement 130 de la structure principale 4 par rapport à l'emballage 2 diffèrent par rapport au premier mode de réalisation préféré. Les autres éléments du conteneur 100 sont ainsi identiques ou similaires à ceux du conteneur 1 selon le premier mode de réalisation préféré décrit ci-dessus.In this second preferred embodiment of the present invention, only the spacing means 130 of the main structure 4 relative to the package 2 differ from the first preferred embodiment. The other elements of the container 100 are thus identical or similar to those of the container 1 according to the first preferred embodiment described above.
En effet, l'espace annulaire prévu entre la structure principale 4 et la paroi interne latérale 24 n'est plus partiellement ou totalement comblé par les secteurs déformables 32 du premier mode de réalisation, mais reste un espace vide 150 évitant tout contact direct entre la paroi interne latérale 24 et la structure principale 4, de façon à autoriser une déformation ponctuelle de cette paroi interne latérale 24 de l'emballage 2 lors d'une épreuve de poinçonnement . Dans ce second mode de réalisation préféré, les moyens d'espacement 130 sont prévus sur le fond fixe 8 ou sur le couvercle 10 de l'emballage 2, ou de préférence sur les deux. Ces moyens d'espacement 130 permettent ainsi de centrer la structure principale 4 sur l'axe principal longitudinal 19 du conteneur 100, de manière à obtenir un espace annulaire vide 150 d'épaisseur sensiblement constante.Indeed, the annular space provided between the main structure 4 and the lateral internal wall 24 is no longer partially or completely filled by the deformable sectors 32 of the first embodiment, but remains an empty space 150 avoiding any direct contact between the lateral internal wall 24 and the main structure 4, so as to allow a punctual deformation of this lateral internal wall 24 of the package 2 during a punching test. In this second preferred embodiment, the spacing means 130 are provided on the fixed bottom 8 or on the cover 10 of the package 2, or preferably on both. These spacing means 130 thus make it possible to center the main structure 4 on the main longitudinal axis 19 of the container 100, so as to obtain an empty annular space 150 of substantially constant thickness.
Comme cela est visible sur la figure 6, les moyens d'espacement 130 comportent par exemple une pluralité de moyens de centrage 152, prévus sur le fond fixe 8 et sur le couvercle 10 et dirigés vers l'intérieur du conteneur 100 (seuls les moyens de centrage 152 solidaires du couvercle 10 étant représentés) . Chaque moyen de centrage 152 est disposé selon un axe identique à celui d'un logement 26 de la structure principale 4 , de manière à pouvoir pénétrer dans ce même logement 26. De cette façon, les moyens de centrage 152 placés sur le couvercle 10 et le fond 8 de l'emballage 2 sont aptes à supporter latéralement la structure principale 4, afin de la maintenir par rapport à la paroi interne latérale 24 du conteneur 100. En prévoyant ainsi plusieurs moyens de centrage 152 coopérant chacun avec un logement 26, la structure principale 4 du conteneur 100 est susceptible d'être maintenue de façon centrée sur l'emballage 2, lorsque le couvercle 10 est assemblé sur la face latérale 6 de cet emballage 2.As can be seen in FIG. 6, the spacing means 130 comprise for example a plurality of centering means 152, provided on the fixed bottom 8 and on the cover 10 and directed towards the interior of the container 100 (only the means centering 152 integral with the cover 10 being shown). Each centering means 152 is arranged along an axis identical to that of a housing 26 of the main structure 4, so as to be able to penetrate this same housing 26. In this way, the centering means 152 placed on the cover 10 and the bottom 8 of the packaging 2 are able to laterally support the main structure 4, in order to maintain it with respect to the lateral internal wall 24 of the container 100. By thus providing several centering means 152 each cooperating with a housing 26, the main structure 4 of the container 100 can be maintained centered on the packaging 2, when the cover 10 is assembled on the side face 6 of this packaging 2.
Bien entendu, dans ce second mode de réalisation préféré de l'invention, tous autres moyens d'espacement 130 peuvent être envisagés entre d'une part la structure principale 4 et d'autre part le fond fixe 8 et/ou le couvercle 10 de l'emballage 2, sans sortir du cadre de l'invention.Of course, in this second preferred embodiment of the invention, any other spacing means 130 can be envisaged between a share the main structure 4 and secondly the fixed bottom 8 and / or the cover 10 of the package 2, without departing from the scope of the invention.
En outre, il est précisé que lors d'une épreuve de poinçonnement, le comportement du conteneurIn addition, it is specified that during a punching test, the behavior of the container
100 est analogue à celui présenté ci-dessus pour le conteneur 1 selon le premier mode de réalisation préféré de l'invention.100 is analogous to that presented above for the container 1 according to the first preferred embodiment of the invention.
En effet, comme dans le cas rencontré dans le premier mode de réalisation préféré où la déformation de la paroi interne latérale 24 se situe dans une zone dépourvue de moyens d'espacement 30, la paroi interne latérale 24 du conteneur 100 se déforme alors tout simplement dans le vide de l'espace annulaire 150 pratiqué entre les éléments 2 et 4 , selon sensiblement la même amplitude que celle qui aurait été obtenue en présence de moyens d'espacement à fonction de fusible mécanique, interposés entre la paroi interne latérale 24 et la structure principale 4. Bien entendu, diverses modifications peuvent être apportées par l'homme du métier aux conteneurs 1,100 pour le stockage/transport de matières radioactives non irradiées qui viennent d'être décrits, uniquement à titre d'exemples non limitatifs. Indeed, as in the case encountered in the first preferred embodiment where the deformation of the lateral internal wall 24 is located in an area devoid of spacing means 30, the lateral internal wall 24 of the container 100 then simply deforms in the void of the annular space 150 formed between the elements 2 and 4, according to substantially the same amplitude as that which would have been obtained in the presence of spacing means acting as a mechanical fuse, interposed between the internal lateral wall 24 and the main structure 4. Of course, various modifications can be made by those skilled in the art to 1,100 containers for the storage / transport of non-irradiated radioactive materials which have just been described, only by way of non-limiting examples.

Claims

REVENDICATIONS
1. Conteneur (1,100) pour le stockage/transport de matières radioactives non irradiées telles que des assemblages de combustible nucléaire, ledit conteneur (1,100) comprenant une structure principale (4) et un emballage (2) comportant une paroi interne latérale (24) définissant une cavité à l'intérieur de laquelle est apte à être logée ladite structure principale (4) , cette dernière définissant une pluralité de logements (26) chacun apte à recevoir au moins un assemblage de combustible, caractérisé en ce que le conteneur (1,100) comporte en outre des moyens d'espacement (30,130) de la structure principale (4) par rapport à l'emballage (2), les moyens d'espacement (30,130) étant aptes à éviter tout contact direct entre ladite paroi interne latérale (24) et la structure principale (4) , de façon à autoriser une déformation ponctuelle de cette paroi interne latérale (24) de l'emballage (2) lors d'une épreuve de poinçonnement.1. Container (1,100) for the storage / transport of non-irradiated radioactive materials such as nuclear fuel assemblies, said container (1,100) comprising a main structure (4) and a package (2) having a lateral internal wall (24) defining a cavity inside which is able to be accommodated said main structure (4), the latter defining a plurality of housings (26) each suitable for receiving at least one fuel assembly, characterized in that the container (1,100 ) further comprises spacing means (30,130) of the main structure (4) relative to the packaging (2), the spacing means (30,130) being able to avoid any direct contact between said lateral internal wall ( 24) and the main structure (4), so as to allow a point deformation of this lateral internal wall (24) of the packaging (2) during a punching test.
2. Conteneur (1) selon la revendication 1, dans lequel les moyens d'espacement (30) de la structure principale (4) par rapport à l'emballage (2) sont prévus entre ladite structure principale (4) et la paroi interne latérale (24) de l'emballage (2), lesdits moyens d'espacement (30) disposant d'une fonction de fusible mécanique afin de se déformer lors d'une déformation ponctuelle de la paroi interne latérale2. Container (1) according to claim 1, wherein the spacing means (30) of the main structure (4) relative to the packaging (2) are provided between said main structure (4) and the internal wall side (24) of the packaging (2), said spacing means (30) having a mechanical fuse function in order to deform during a punctual deformation of the lateral internal wall
(24) de l'emballage (2), survenant lors d'une épreuve de poinçonnement. (24) of the packaging (2), occurring during a punching test.
3. Conteneur (1) selon la revendication 2, dans lequel les moyens d'espacement (30) sont composés d'une pluralité de secteurs déformables (32) répartis autour de ,1a structure principale (4) du conteneur (1) . 3. Container (1) according to claim 2, wherein the spacing means (30) are composed of a plurality of deformable sectors (32) distributed around the main structure (4) of the container (1).
4. Conteneur (1) selon la revendication 3, dans lequel au moins un secteur déformable (32) s'étend sur sensiblement toute la longueur de la structure principale (4) du conteneur (1) .4. Container (1) according to claim 3, wherein at least one deformable sector (32) extends over substantially the entire length of the main structure (4) of the container (1).
5. Conteneur (1) selon la revendication 3 ou la revendication 4, dans lequel au moins deux secteurs déformables (32) sont empilés les uns sur les autres selon une direction parallèle à un axe principal longitudinal (19) du conteneur (1) .5. Container (1) according to claim 3 or claim 4, wherein at least two deformable sectors (32) are stacked on each other in a direction parallel to a main longitudinal axis (19) of the container (1).
6. Conteneur (1) selon l'une quelconque des revendications 3 à 5, dans lequel au moins un secteur déformable (32) est réalisé dans un matériau à faible contrainte d'écrasement.6. Container (1) according to any one of claims 3 to 5, wherein at least one deformable sector (32) is made of a material with low crushing stress.
7. Conteneur (1) selon la revendication 6, dans lequel ledit matériau est un élément pris parmi un groupe constitué du bois, de la mousse plastique et du nid-d' abeilles .7. Container (1) according to claim 6, wherein said material is an element taken from a group consisting of wood, plastic foam and honeycomb.
8. Conteneur (1) selon l'une quelconque des revendications 3 à 5, dans lequel au moins un secteur déformable (32) est un élément métallique prenant la forme de deux tôles concentriques (40,42) séparées par des renforts (44) .8. Container (1) according to any one of claims 3 to 5, in which at least one deformable sector (32) is a metallic element taking the form of two concentric sheets (40,42) separated by reinforcements (44) .
9. Conteneur (1) selon la revendication 8, dans lequel les renforts (44) sont inclinés par rapport à un rayon d'un cercle concentrique auxdites tôles (40,42), et agencés de . manière à ce que deux renforts (44) successifs soient inclinés selon un sens opposé. 9. Container (1) according to claim 8, wherein the reinforcements (44) are inclined relative to a radius of a circle concentric with said sheets (40,42), and arranged. so that two successive reinforcements (44) are inclined in an opposite direction.
10. Conteneur (1) selon la revendication 8 ou la revendication 9, dans lequel les éléments métalliques sont réalisés en aluminium ou dans l'un de ses alliages. 10. Container (1) according to claim 8 or claim 9, wherein the metal elements are made of aluminum or one of its alloys.
11. Conteneur (1) selon l'une quelconque des revendications 3 à 10, dans lequel les secteurs déformables (32) sont fixés sur ladite structure principale (4) du conteneur (1) .11. Container (1) according to any one of claims 3 to 10, in which the deformable sectors (32) are fixed on said main structure (4) of the container (1).
12. Conteneur (1) selon l'une quelconque des revendications 2 à 11, dans lequel les moyens d'espacement (30) recouvrent totalement la structure principale (4) du conteneur (1) .12. Container (1) according to any one of claims 2 to 11, in which the spacing means (30) completely cover the main structure (4) of the container (1).
13. Conteneur (1) selon l'une quelconque des revendications 2 à 11, dans lequel les moyens d'espacement (30) recouvrent uniquement partiellement la structure principale (4) du conteneur (1) .13. Container (1) according to any one of claims 2 to 11, wherein the spacing means (30) only partially cover the main structure (4) of the container (1).
14. Conteneur (100) selon la revendication 1, dans lequel les moyens d'espacement (130) de la structure principale (4) par rapport à l'emballage (2) sont prévus sur au moins un des éléments pris parmi un groupe constitué d'un couvercle (10) et d'un fond fixe14. Container (100) according to claim 1, wherein the spacing means (130) of the main structure (4) relative to the packaging (2) are provided on at least one of the elements taken from a group consisting a cover (10) and a fixed bottom
(12) de l'emballage (2), la paroi interne latérale (24) de l'emballage (2) et la structure principale (4) étant séparées par un espace vide (150) . (12) of the package (2), the lateral internal wall (24) of the package (2) and the main structure (4) being separated by an empty space (150).
15. Conteneur (1,100) selon l'une quelconque des revendications précédentes, dans lequel la structure principale (4) du conteneur (1,100) dispose d'une forme sensiblement cylindrique de section circulaire . 15. Container (1,100) according to any one of the preceding claims, in which the main structure (4) of the container (1,100) has a substantially cylindrical shape of circular section.
16. Conteneur (1,100) selon l'une quelconque des revendications précédentes, dans lequel la paroi interne latérale (24) de l'emballage (2) et la structure principale (4) sont séparées par un espace de forme sensiblement annulaire.16. Container (1,100) according to any one of the preceding claims, in which the lateral internal wall (24) of the package (2) and the main structure (4) are separated by a space of substantially annular shape.
17. Conteneur (1,100) selon l'une quelconque des revendications précédentes, dans lequel l'emballage (2) comprend une face latérale (6) de forme sensiblement annulaire, constituée par une virole interne (16) et une virole externe (18) , lesdites viroles (16,18) étant espacées et maintenues l'une par rapport à l'autre par l'intermédiaire de raidisseurs17. Container (1,100) according to any one of the preceding claims, in which the packaging (2) comprises a lateral face (6) of substantially annular shape, constituted by an internal ferrule (16) and an external ferrule (18) , said ferrules (16,18) being spaced and held relative to each other by means of stiffeners
(20) . (20).
EP03786049A 2002-11-06 2003-11-04 Container for the storage/transport of unirradiated radioactive materials such as nuclear fuel assemblies Expired - Lifetime EP1576621B1 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
FR0213861A FR2846778B1 (en) 2002-11-06 2002-11-06 CONTAINER FOR STORAGE / TRANSPORT OF NON-IRRADIATED RADIOACTIVE MATERIALS SUCH AS NUCLEAR FUEL ASSEMBLIES
FR0213861 2002-11-06
PCT/FR2003/050113 WO2004044925A2 (en) 2002-11-06 2003-11-04 Container for the storage/transport of unirradiated radioactive materials such as nuclear fuel assemblies

Publications (3)

Publication Number Publication Date
EP1576621A2 true EP1576621A2 (en) 2005-09-21
EP1576621A3 EP1576621A3 (en) 2005-11-23
EP1576621B1 EP1576621B1 (en) 2008-01-09

Family

ID=32104487

Family Applications (1)

Application Number Title Priority Date Filing Date
EP03786049A Expired - Lifetime EP1576621B1 (en) 2002-11-06 2003-11-04 Container for the storage/transport of unirradiated radioactive materials such as nuclear fuel assemblies

Country Status (6)

Country Link
EP (1) EP1576621B1 (en)
JP (1) JP4727229B2 (en)
AU (1) AU2003295054A1 (en)
DE (1) DE60318625T2 (en)
FR (1) FR2846778B1 (en)
WO (1) WO2004044925A2 (en)

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EP2579263A1 (en) * 2010-05-25 2013-04-10 Mitsubishi Heavy Industries, Ltd. Radioactive substance storage container

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FR3076058B1 (en) * 2017-12-22 2020-01-24 Tn International ASSEMBLY COMPRISING A PACKAGE FOR TRANSPORTING RADIOACTIVE MATERIALS AND MEANS FOR LIFTING THE PACKAGE IN RELATION TO A BASIC PLATFORM
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EP2579263A4 (en) * 2010-05-25 2013-10-23 Mitsubishi Heavy Ind Ltd Radioactive substance storage container

Also Published As

Publication number Publication date
AU2003295054A1 (en) 2004-06-03
EP1576621B1 (en) 2008-01-09
EP1576621A3 (en) 2005-11-23
DE60318625T2 (en) 2009-01-08
WO2004044925A2 (en) 2004-05-27
JP4727229B2 (en) 2011-07-20
FR2846778A1 (en) 2004-05-07
DE60318625D1 (en) 2008-02-21
JP2006505780A (en) 2006-02-16
FR2846778B1 (en) 2005-04-08
WO2004044925A3 (en) 2005-10-06

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