EP2419908B1 - Packaging device for transporting and storage and intermediate storage of radioactive materials - Google Patents

Description

The present invention relates generally to the field of transport and / or storage of a radioactive medium generating by radiolysis flammable and / or explosive gases, such as hydrogen.

• un milieu liquide radioactif ;
• une poudre d'oxyde de plutonium (PuO2) ou d'oxyde mixte uranium-plutonium (U02-PU02), encore appelée poudre MOX, par exemple à teneur en humidité supérieure 0,5 % ;
• des déchets technologiques comportant des composés organiques et éventuellement de l'eau, ces déchets pouvant être contaminés par de l'uranium ou du plutonium conférant à ces matières un caractère radioactif ;
• des crayons de combustible nucléaire pas étanches, irradiés ou frais, pouvant contenir de l'eau ;
• des tronçons de crayons de combustible nucléaire comportant de la résine permettant de figer la matière radioactive.

These may be radioactive media of different kinds, such as:

• a radioactive liquid medium;
• a plutonium oxide powder (PuO2) or mixed uranium-plutonium oxide (U02-PU02), also called MOX powder, for example with a moisture content greater than 0.5%;
• technological waste containing organic compounds and possibly water, which waste may be contaminated by uranium or plutonium conferring on these substances a radioactive character;
• nuclear fuel rods that are not waterproof, irradiated or fresh, that may contain water;
• sections of nuclear fuel rods comprising resin for freezing the radioactive material.

STATE OF THE PRIOR ART

In known manner, such a radioactive medium is usually placed in an interior storage space defined by a bottle. When several bottles are filled and closed by plugs, they are then arranged on a bottle holder and inserted into a cavity defined by a package. The set obtained, called transport package and / or storage of a radioactive medium, may for example include ten bottles distributed on the bottle carrier.

In the case of a radioactive liquid medium, which usually comprises plutonium, it is likely to generate by radiolysis flammable and / or explosive gases, such as hydrogen. This is explained by the fact that the radioactive medium, whether it is a liquid in which the radioactive material is in ionic form and / or in the form of solid particles dispersed in the liquid, constitutes an α-particle emitter which has in particular the particularity of dissociating the hydrogenated molecules, to release flammable gaseous compounds. In this respect, it is noted that the radiolysed molecules may be part of the medium, and / or the constituent material of the canister.

In any case, when their concentration exceeds a limit value known as the "flammability threshold", the flammable gases produced by radiolysis constitute, in the presence of other gases such as air, an explosive mixture. The flammability threshold varies according to the nature of the gas flammable and according to the conditions of temperature and pressure. In the particular case of hydrogen, the flammability threshold in the air is around 4%. This means that when the hydrogen concentration in the air exceeds this threshold, a source of heat or a spark can be enough to ignite the mixture or to produce a violent explosion in the internal storage space, the latter being indeed only partially filled by the radioactive medium, and supplemented by a gaseous sky.

However, various studies have shown that the concentration of flammable gases, such as hydrogen, produced by radiolysis in a can containing an aqueous plutoniferous medium, can sometimes reach values of about 4% after a few days. However, it is common for a bottle to remain closed for much longer periods before being opened. There is therefore a real risk of accident, because a spark caused by shocks or friction can occur during transport in the interior space of the canister containing the gas. In addition, this risk remains during the opening operations of the canopy.

To cope with this problem, the volume of the radioactive medium placed in the canopy can be reduced. This makes it possible to obtain a gaseous sky of greater volume, in which the flammability threshold of the flammable gases is reached later. Nevertheless, this solution is not satisfactory from an economic point of view, since it requires a multiplication of transport.

Another solution could be to keep the same volume of radioactive medium in the bottle, but by enlarging the internal storage space so as to increase the volume of the gas. Nevertheless, this leads to the manufacture of very large bottles, which makes their exploitation difficult, especially during the loading phases of the radioactive medium in the canister, which is generally carried out in a glove box.

This type of disadvantage also occurs with the other radioactive media mentioned below, since they are capable of generating, by radiolysis, flammable and / or explosive gases. In all cases, it is always the water contained in the bottle which is radiolysed, except for the case of the resin, where it is this same resin which is radiolysed.

STATEMENT OF THE INVENTION

The invention therefore aims to at least partially overcome the disadvantages mentioned above, relating to the achievements of the prior art.

To do this, the invention firstly relates to a packaging device for transporting and / or storing a radioactive medium generating by radiolysis of flammable and / or explosive gases, said device comprising at least one bottle for contain the radioactive medium, said bottle defining an internal storage space accessible through a filling opening of the medium, on which are mounted plug means.

According to the invention, said device also comprises an enclosure structure, as well as communication means for establishing a first fluid communication between said internal storage space and said enclosure.

Thus, the flammable and / or explosive gases produced by radiolysis during the storage and / or transport of the radioactive medium can spread not only in the unfilled part of the interior storage space of the canister, called gaseous sky, but also in the volume of the enclosure through the presence of said first fluid communication. Since the gases generated by radiolysis can be diluted in a larger volume than that of the simple gas sky of the canister, each can can therefore contain a larger amount of radioactive medium, without risking to reach the threshold of flammability of these gas. This increase in the filling rate of the canisters implies a significant economic gain, since for a given amount of medium, it reduces the number of transports to be performed.

On the other hand, the invention also makes it possible to increase the duration of transport / storage, without risking to reach the flammability threshold of the gases generated by radiolysis, always because these gases can be diluted in a larger volume.

In addition, each bottle can remain small in size, favoring easier operation, particularly with regard to the operation of filling of the medium in the internal storage space, which is usually done in a glove box. It is only after the filling and the installation of the cap means that the internal storage space and the enclosure are put into fluid communication. In this regard, it is noted that if each bottle is preferably designed to be arranged outside the chamber, preferably being removably mounted on the structure, it is possible to provide an embodiment in which each bottle is housed in the enclosure with which its internal storage space communicates. Also, in the case where the canisters are arranged outside the enclosure, they can alternatively be placed at a distance from the enclosure structure without being mounted mechanically thereon.

The invention applies to the conditioning of radioactive liquid media, but also to the packaging of all other radioactive media capable of generating, by radiolysis, flammable and / or explosive gases.

According to a first preferred embodiment of the present invention,
the bottle further comprises a first orifice opening into the internal storage space,
said enclosure structure comprises a second orifice opening into said enclosure,
and said first and second ports constitute the two opposite ends of said first fluid communication.

This first embodiment corresponds to a case where the bottle is intended to be arranged outside the enclosure, being preferably removably mounted on the structure. Said first fluid communication can integrate any element between the first and second orifices, in particular controllable means alternatively for releasing / closing these first and second orifices.

As such, said communication means preferably comprise a first movable member between an open position in which it establishes said first fluidic communication, and a closed position in which it closes said second orifice, said first movable member being mounted on said enclosure structure.

This first movable member can indifferently constitute an actuating member for establishing the first fluid communication, or constitute a follower member of this actuating member. In both cases, the actuator can be manually controlled by an operator, or be set in motion automatically, in response to an operator-activated signal.

According to a second preferred embodiment of the present invention,
the bottle further comprises a third orifice opening into the internal storage space,
said enclosure structure comprises a fourth orifice opening into said enclosure,
and said communicating means makes it possible to establish a second fluid communication between said internal storage space and said enclosure, said third and fourth orifices constituting the two opposite ends of said second fluid communication.

With this second embodiment, which is very similar to the first embodiment, the flammable and / or explosive gases produced by radiolysis during the storage and / or transport of the radioactive medium can spread in the volume of the enclosure by borrowing both said first fluid communication and said second fluid communication. Moreover, a number of fluidic communications greater than two could be provided between the chamber and the interior storage space of the canopy, without departing from the scope of the invention.

According to a third preferred embodiment of the present invention,
the bottle further comprises a third orifice opening into the internal storage space,
said enclosure structure comprises a fourth orifice opening into said enclosure,
said communicating means make it possible to establish a second fluid communication between said internal storage space and said enclosure, said third and fourth orifices constituting the two opposite ends of said second fluid communication,
and fifth and sixth orifices are formed in the enclosure structure, and communicate with each other through a connecting conduit integral with said communicating means.

• en position ouverte, d'une part il met en communication ledit premier orifice avec ledit cinquième orifice, et d'autre part il établit ladite seconde communication fluidique en mettant en communication ledit troisième orifice avec ledit quatrième orifice ;
• en position fermée, d'une part il assure une mise en communication du quatrième orifice avec ledit cinquième orifice, et d'autre part il interdit la communication de chacun des quatrième et cinquième orifices avec l'extérieur de ladite enceinte,
  et en ce que ledit second organe mobile étant conçu de sorte que :
• en position ouverte, d'une part il met en communication ledit sixième orifice avec l'extérieur de ladite enceinte, et d'autre part il met en communication ledit second orifice avec l'extérieur de ladite enceinte ;
• en position fermée, d'une part il assure une mise en communication du sixième orifice avec ledit second orifice, et d'autre part il interdit la communication de chacun des second et sixième orifices avec l'extérieur de ladite enceinte.

This third preferred embodiment is specially adapted to perform the inerting of the various components of the packaging device. Preferably, said communication means comprise a first movable member and a second movable member each mounted on said enclosure structure and movable between an open position and a closed position, said first movable member being designed so that:

• in the open position, on the one hand it puts said first orifice into communication with said fifth orifice, and on the other hand it establishes said second fluid communication by placing said third orifice in communication with said fourth orifice;
• in the closed position, on the one hand it ensures a communication of the fourth port with said fifth port, and on the other hand it prohibits the communication of each of the fourth and fifth ports with the outside of said enclosure,
  and in that said second movable member is so designed that:
• in the open position, on the one hand it puts in communication said sixth orifice with the outside of said enclosure, and on the other hand it puts in communicating said second orifice with the outside of said enclosure;
• in the closed position, on the one hand it ensures a communication of the sixth port with said second port, and on the other hand it prohibits the communication of each of the second and sixth orifices with the outside of said enclosure.

Thus, by adopting an appropriate combination of positions for the two movable members, it is alternatively possible to perform the inerting of the canister and the chamber, the inerting of the enclosure only, to establish the first / second fluid communication , and to place the enclosure in closed circuit.

Here too, the first movable member can indifferently constitute an actuating member for establishing the first fluid communication, or constitute a follower member of this actuating member. In both cases, this actuating member may be manually controlled by an operator, or may be set in motion automatically, in response to an operator activated signal.

In this respect, whatever the embodiment envisaged, said bottle preferably comprises a first additional movable member, movable between an open position in which it establishes said first fluidic communication, and a closed position in which it closes said first orifice, one of the first movable member and the first additional movable member being an actuating member and the other a follower member of the member actuating means, so that the movement of the actuating member from its closed position to its open position causes said follower member to also move from its closed position to its open position, and vice versa.

In other words, the first movable member is dedicated to closing / releasing the second orifice opening into the chamber, while the first additional movable member is dedicated to closing / releasing the first orifice opening into the chamber. internal storage space of the canopy, with one or the other of these bodies can be an actuating member, preferably manually operable by an operator, and driving the other of these two bodies.

Preferably, said actuator also constitutes a mechanical connection member of said bottle on the enclosure structure, this mechanical connection function thus adding to that of establishing / breaking the first fluid communication.

Preferably, the actuating member is designed such that its displacement from its closed position to its open position, with said canister resting on this first movable member, ensures a mechanical connection of the canopy, and so that the moving from its open position to its closed position ensures a mechanical disconnection of this bottle. Therefore, a single action on this actuator can generate simultaneously effects on the mechanical connection, as well as effects on fluid communication.

Preferably, said actuating member forms a male or female portion of a bayonet mechanical connection.

Preferably, the device comprises a plurality of bottles each associated with communication means for a first fluid communication between its interior space and said enclosure. As a result, several bottles share the same enclosure, implying an optimization of the device in terms of weight and bulk.

• en position ouverte, d'une part il met en communication chacun des sixièmes orifices avec l'extérieur de ladite enceinte, et d'autre part il met en communication ledit second orifice unique avec l'extérieur de ladite enceinte ; et
  • en position fermée, d'une part il assure une mise en communication de chacun des sixièmes orifices avec ledit second orifice unique, et d'autre part il interdit la communication de chacun du second orifice unique et des sixièmes orifices avec l'extérieur de ladite enceinte.

Preferably, in the case of the third preferred embodiment, the communication means of all the bottles share the same second orifice,
and said second movable member is designed so that:

• in the open position, on the one hand it puts in communication each of the sixth orifices with the outside of said enclosure, and on the other hand it puts in communication said second single orifice with the outside of said enclosure; and
  • in the closed position, on the one hand it ensures a communication of each of the sixth orifices with said second single orifice, and on the other hand it prohibits the communication of each of the second single orifice and the sixth orifices with the outside of said pregnant.

Consequently, the only actuation of the second movable member makes it possible to have an effect on all the bottles simultaneously, so that it follows a simplification of orders.

The invention also relates to an assembly comprising said conditioning device being in any of the forms described above. In this set, each can houses in its internal storage space a given volume of radioactive medium, defining a level forming a horizontal demarcation with a gas sky completing this internal storage space, said communication means associated with said bottle presenting a first orifice opening into said internal storage space, and arranged so that it is always in communication with the gas, regardless of the orientation in the space of said bottle incorporating said given volume of medium. Here, the invention applies more particularly to radioactive liquid media, and, more generally, to any medium whose consistency makes it possible to define a level forming the horizontal demarcation with the gaseous sky.

In other words, whatever the position of the canopy in the space, at least a portion of the open end of the first orifice does not bathe in the middle, and this in order to always allow the exhaust gas produced by radiolysis towards the enclosure.

Thus, in the event of accident conditions where the device would no longer be in the normal storage / storage position, namely vertically, the fluid communication between the gaseous bottle and the enclosure remains preserved. This avoids the risk of sudden overshoot of the flammability threshold of gas in the gaseous sky of the canister.

Preferably, this first orifice is made at least partly in a duct projecting inside said internal storage space. In addition, it opens preferentially near a barycentre of said inner storage space.

The invention also relates to a transport package and / or storage of a radioactive medium, comprising a package forming a cavity in which is housed an assembly as described above.

The invention also relates to a transport container and / or storage of a radioactive medium, comprising a package forming a cavity in which is housed a packaging device as described above. This container differs from the package mentioned above in that the packaging device is empty, that is to say that it does not contain the radioactive medium.

• on introduit le milieu radioactif dans l'espace intérieur de stockage du bouteillon ;
• on ferme le bouteillon à l'aide des moyens formant bouchon ; et
• on établit ladite première communication fluidique entre ledit espace intérieur de stockage et ladite enceinte.

Finally, the invention also relates to a method for conditioning a radioactive medium in a packaging device for the transport and / or storage of a radioactive medium, in which:

• the radioactive medium is introduced into the internal storage space of the canister;
• the bottle is closed using the cap means; and
• said first fluid communication is established between said internal storage space and said enclosure.

Other advantages and features of the invention will become apparent in the detailed non-limiting description below.

BRIEF DESCRIPTION OF THE DRAWINGS

• la figure 1 représente une vue en perspective, partiellement éclatée, d'un colis de transport et/ou entreposage d'un milieu radioactif, selon un premier mode de réalisation préféré de l'invention ;
• la figure 1a représente une vue partielle en coupe montrant l'un des bouteillons monté sur la structure formant enceinte, avec le premier organe mobile en position ouverte établissant la communication fluidique entre cette enceinte et le bouteillon ;
• la figure 1b représente une vue similaire à celle de la figure 1a, avec le premier organe mobile en position fermée interdisant la communication fluidique entre l'enceinte et le bouteillon ;
• la figure 1b' représente une vue en coupe prise le long de la ligne Ib'-Ib' de la figure 1b ;
• la figure 1c représente une vue schématique en perspective montrant le mécanisme de connexion mécanique à baïonnette prévu pour monter le bouteillon sur la structure formant enceinte ;
• la figure 1d représente une vue similaire à celle de la figure 1b, avec le premier organe mobile, montré en position fermée, se présentant sous la forme d'une alternative de réalisation ;
• les figures 2a et 2b représentent des vues respectivement similaires aux vues montrées sur les figures 1a et 1b, avec le dispositif de conditionnement se présentant sous la forme d'un second mode de réalisation préféré de la présente invention ;
• les figures 3a à 3d représentent le dispositif de conditionnement selon un troisième mode de réalisation préféré de la présente invention, dans différentes configurations d'utilisation ;
• la figure 3c' représente une vue en coupe prise le long de la ligne IIIc'-IIIc' de la figure3c ;
• les figures 3e et 3f représentent des vues en coupe du second organe mobile, montré respectivement en positions ouverte et fermée, et se présentant sous la forme d'une alternative de réalisation ;
• la figure 4a montre une autre possibilité de réalisation du premier orifice débouchant dans l'espace intérieur de stockage du bouteillon, avec ce bouteillon orienté dans une position verticale telle qu'adoptée en conditions normales de transport et/ou entreposage ; et
• la figure 4b représente une vue similaire à celle de la figure 4a, avec le bouteillon orienté dans une position inclinée susceptible d'être adoptée en conditions accidentelles.

This description will be made with reference to the appended drawings among which;

• the figure 1 is a perspective view, partially exploded, of a transport package and / or storage of a radioactive medium, according to a first preferred embodiment of the invention;
• the figure 1a is a partial sectional view showing one of the bottles mounted on the enclosure structure, with the first movable member in the open position establishing the fluid communication between the chamber and the canister;
• the figure 1b represents a view similar to that of the figure 1a with the first movable member in closed position prohibiting fluid communication between the enclosure and the canister;
• the figure 1b ' represents a sectional view taken along the line Ib'-Ib 'of the figure 1b ;
• the figure 1c is a schematic perspective view showing the bayonet mechanical connection mechanism for mounting the canopy on the enclosure structure;
• the figure 1d represents a view similar to that of the figure 1b with the first movable member shown in the closed position, in the form of an alternative embodiment;
• the Figures 2a and 2b represent respectively similar views to the views shown on the figures 1a and 1b with the packaging device in the form of a second preferred embodiment of the present invention;
• the Figures 3a to 3d represent the packaging device according to a third preferred embodiment of the present invention, in different configurations of use;
• the figure 3c ' represents a sectional view taken along the line IIIc'-IIIc 'of the figure3c ;
• the Figures 3e and 3f represent sectional views of the second movable member, respectively shown in open and closed positions, and being in the form of an alternative embodiment;
• the figure 4a shows another possibility of making the first orifice opening into the interior storage space of the canister, with this canister oriented in a vertical position as adopted under normal conditions of transport and / or storage; and
• the figure 4b represents a view similar to that of the figure 4a , with the canister oriented in an inclined position likely to be adopted in accident conditions.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Firstly with reference to the figure 1 , we can see a transport package and / or storage of a radioactive medium, according to a first preferred embodiment of the invention. This radioactive medium is preferably a liquid in which the radioactive material is in ionic form and / or in the form of solid particles dispersed in the liquid.

The package 1 comprises a device 2 for conditioning the transport and / or storage of the radioactive medium, this device being also an object of the present invention.

As shown schematically on the figure 1 , the conditioning device 2, optionally covered with a vinyl sleeve (not shown), is housed in a barrel 4 closed by a cover 4a. The barrel 4 is then itself housed in the cavity 5 of a package 6, closed by a lid 6a, in order to form the package 1.

The conditioning device 2 has the particularity of comprising a plurality of bottles 8, as well as a structure 10 forming an enclosure 12. Each bottle 8 defines an internal storage space in which the radioactive medium is placed, this space being closed by means 14, by which the can is mechanically connected to the structure 10, removably.

In this respect, the structure 10 adopts a generally cylindrical shape of axis 16 and of circular section, which has recesses 18 distributed circumferentially to accommodate the bottles 8. As visible on the figure 1 each recess 18, similar to an impression, opens radially towards outside and axially downwards, having dimensions slightly greater than those of the canister 8 it receives. The bottles 8, arranged parallel to and about the axis 16, can be inserted into their respective recesses by axial displacement and / or radial.

Thus, it is for example five bottles that can be installed on the structure 10 externally to the chamber 12, in the recesses 18 provided in an identical number.

Referring now to the figure 1a , one can see one of the bottles 8 removably mounted on the structure 10 forming enclosure 12, with its means 14 forming a plug. These means 14 seal a filling opening 20 provided in the upper part of the internal storage space 22 of the canister 8, this opening 20 allowing the prior introduction of the radioactive medium (not shown) in the space 22, made in a box. gloves. Here, the opening 20 has a substantially identical diameter to the average diameter of the canister, which also takes a generally cylindrical shape of circular section. The bottle can nevertheless take any other form, such as that of a case or box, preferably metal.

The cap means 14 comprise a first closure piece 24, for example screwed onto the upper end of the lateral body 26 of the canopy, through which is made a first through hole 30a which opens into the internal storage space 22 This is this piece 24 which covers the opening 20 defined by the lateral body 26. The means 14 further comprises a second closure piece 32, for example rotatably mounted on the first closure piece 24, and whose essential function lies in the closing / releasing the first through hole 30a. To do this, the piece 32 also has a through passage 34 may be aligned or eccentric of the first port 30a, depending on the relative angular position between the two closure pieces 24, 32.

The structure 10, in the form of a wall delimiting the chamber 12, integrates a second through hole 30b, which opens into the chamber 12. This second orifice 30b is formed in the part of the structure 10 which defines the end upper imprint 18, facing the means 14 forming the bottle stopper. A first movable member 36 is mounted externally on the structure 10, in line with the second orifice 30b, so as to be able to ensure the closure / release of this orifice 30b.

To do this, the movable member 36 also comprises a through passage 38 capable of being aligned or eccentric of the second orifice 30b, as a function of the relative angular position between the movable member 36 and the structure 10.

In the configuration shown on the figure 1a , the bottle 8 is not only mounted mechanically on the structure 10 in a manner to be described later, but a first fluid communication 40 is also established between the space 22 and the enclosure 12. This communication 40 is initiated by the first port 30a, is extended by the passages 34 and 38 being in the continuity of one another, then ends with the second port 30b. Thus, gas located in the space 22 can pass in a sealed manner towards the chamber 12 by the first channel-forming fluidic communication 40, and vice versa. This is of particular importance, since the flammable and / or explosive gases produced by radiolysis during the storage and / or transport of the radioactive medium can spread in the internal storage space 22, but also in the volume of the pregnant 12.

Here, the movable member 36 also performs the function of actuating member, being controllable by an operator, for example by means of a handle or a lever 42. By rotating this member 36, operator can actually move it from its open position shown on the figure 1a wherein it establishes the first fluid communication 40, at a closed position shown on the Figures 1b and 1b ' in which it closes the second orifice 30b, which leads to breaking the communication 40.

When the canopy 8 is mounted on the structure 10, by being pressed against the movable actuating member 36, the latter is coupled in rotation with the second closure piece 32, for example using pins 44 arranged at the interface, carried by one or other of the members 32, 36. Thus, during the displacement of the movable actuating member 36 of its open position to its closed position, this member 36 carries with it the closing piece 32 in rotation. This last piece 32 then moves simultaneously from its open position shown on the figure 1a wherein it establishes the first fluid communication 40, at its closed position shown on the figure 1b in which it closes the first orifice 30a, which also leads to breaking the communication 40. Due to the rotational drive of which it is the object, the closing piece 32, forming additional mobile member, is described as follower organ.

It is noted that sealing means (not shown), of the seal type, are preferably provided so that the closed position of the additional follower member 32 ensures a tight closure of the internal storage space 22 , and so that the closed position of the movable actuating member 36 ensures a tight closure of the enclosure 12.

To move from the closed position of the members 32, 36 to their open position, the actuating member 36 is controlled manually in the opposite direction to that of the closure. In this respect, the design of the conditioning device 2 is such that the actuating member 36 also constitutes a mechanical connection member of the canopy 8 on the structure 10.

Indeed, the actuating member 36 here forms a male part of a bayonet mechanical connection, for example having two pins 46 of inverted T-shaped section, projecting downwards. as shown on figures 1a , 1b 'and 1c . The female part of the bayonet mechanical connection is then constituted by the first closure piece 24 of the cap means 14, with grooves 48 open on the upper surface of this part, and each having an enlarged end 48a visible on the Figures 1b 'and 1c . Outside its widened end 48a, each groove 48 has a shape complementary to that of its associated pin 48, namely of inverted T-shaped section, open upwards.

Thus, to ensure the desired mechanical connection between the canopy 8 and the structure 10, the can is introduced into its recess 18 so that its first closure piece 24 is pressed against the movable actuating member 36, with the heads spilled T 46 housed in their respective widened ends 48a grooves 48. Then, during the movement by the operator of the member 36 from its closed position to its open position, corresponding for example to a quarter turn, heads reversed T 46s run in the grooves 48 which retain them through their narrowed openings relative to the respective ends 48a. In the open position of the movable member 36, shown on the figure 1a each inverted head 46 is then in its groove 48 at the opposite end of the enlarged end 48a, implying a mechanical connection of the canopy 8 to the structure 10.

Then, when the can 8 is to be mechanically disconnected from the structure 10, the body mobile is again moved by the operator to his closed position shown on the figure 1b ' , still performing a quarter turn, which has the effect of bringing the inverted heads of T 46 in their respective enlarged ends 48a. The bottle 8 mechanically disconnected from the structure 10 only has to be moved axially downwards to be extracted from the conditioning device 2.

Naturally, this principle of mechanical connection / disconnection and rupture / establishment of the first fluid communication is applied for each of the bottles fitted to the conditioning device. In this regard, the device can be used with only some of the recesses 18 filled respectively by canisters, the others remaining free, with the associated movable actuating member 36 placed in the closed position so as to seal the second orifice Corresponding 30b. Alternatively, each recess 18 can accommodate a bottle, possibly covered with a vinyl sleeve, but with one or more of these bottles not filled with radioactive medium. This makes it possible to further increase the volume of the packaging device in which the flammable and / or explosive gases can be diluted, since the bottles communicate with each other through the enclosure.

According to an alternative embodiment of the first mode shown on the figure 1d it is the second shutter piece 32 belonging to the plug means 14 which performs the function of an organ operable by the operator with its lever 42, and the first movable member 36 mounted externally on the structure 10 which acts as a follower member of the actuating member 32. Nevertheless, the operation is similar to that presented above, in particular with the actuating member 32 also constituting a mechanical connection member of the canopy 8 on the structure 10. In fact, the actuating member 32 also forms here a male part of a connection bayonet mechanism, for example having two pins 46 of T-shaped section projecting upwards as shown in FIG. figure 1d . The female part of the bayonet mechanical connection is then constituted by the structure 10, with grooves 48 open downwards, and each having an enlarged end 48a, as described above.

The Figures 2a and 2b show a conditioning device 1 in the form of a second preferred embodiment of the present invention, similar to the first mode described above. In this regard, in the figures, the elements bearing the same reference numerals correspond to identical or similar elements.

Thus, it can be seen that this second mode includes all the features of the first preferred embodiment, to which others have been added in order to be able to establish / break a second fluid communication between the internal storage space. 22 of the canopy and the chamber 12 defined by the structure 10.

As visible on the figure 2a , the second fluid communication 49 is initiated by a third orifice 30c opening into the internal storage space 22, is extended by passages 50 and 52 respectively provided on the second closure piece 32 and the first movable member 36, then ends with a fourth orifice 30d opening into the chamber 12.

Generally speaking, the second fluid communication 49 makes it possible to double the already planned one, and is based on the same design. Moreover, the establishment of the first and second communications 40, 49 is obtained simultaneously by the simple operation of the first movable member 36, as the breaking of these first and second communications 40, 49 is obtained simultaneously, also by actuating the first movable member 36.

With reference to the figure 3a it is possible to see a conditioning device 1 in the form of a third preferred embodiment of the present invention.

In this third mode, the second fluid communication 49, provided in the second mode, has been retained.

On the other hand, the first fluid communication 40 is modified as follows. It is always initiated by the first orifice 30a of the first closure piece 24 of the cap means, then is extended by the through passages 34 and 38 which succeed one another. Then, it continues with a fifth orifice 30e opening into the chamber, corresponding precisely to the second orifice 30b of the previous embodiments. The first fluid communication 40 is extended by a connecting duct 56 running in the chamber 12, which is thus connected to the fifth orifice 30e at one of its ends, and connected at the other of its ends to a sixth orifice 30f practiced in the structure 10 forming wall of the enclosure. As visible on the figure 3a this sixth orifice 30f is preferably situated on an upper part of the structure 10. Next, a second movable member 60, adopting a closed position such as that represented in this figure, makes it possible to put the sixth orifice 30f into communication with a second orifice 30b adjacent practiced in the structure, and opening into the chamber 12. The first fluid communication 40 thus ends with the second port 30b.

Thus, to obtain the two fluidic communications 40, 49, the first movable actuating member 36 must occupy its open position described with reference to the previous embodiments, while the second movable member 60 must occupy its closed position in which it ensures communicating the second and sixth orifices 30b, 30f, and further prohibiting the communication of each of these orifices 30b, 30f with the outside of the enclosure. To do this, the second movable member 60 is mounted externally on the structure 10, to the right of the orifices 30b, 30f, and comprises an U-shaped internal passage 62 sealingly connecting these two orifices 30b, 30f when it occupies its position. closed position.

The configuration shown on the figure 3a is adopted during the transport / storage of the radioactive medium present in the canisters. Thus, the flammable and / or explosive gases generated by radiolysis in the inner storage space of the canisters can borrow the two fluidic communications 40, 49 to join the chamber 12 in which they can be diluted.

The second movable member 60, rotatably mounted on the structure, is also controllable by an operator, for example by means of a handle or a lever 66. By pivoting this member 60, the operator can effectively move from its closed position shown on the figure 3a wherein it establishes the first fluid communication 40, at an open position shown on the figure 3b in which it allows inerting the canopy 8 and the enclosure 12. In fact, in this open position, for example obtained by making a quarter turn from the closed position, the second movable member 60 aligns the two orifices 30b, 30f with respectively two through passages 68, 70 formed therein, independent of the inner passage 62 in U become inactive, and thus allowing to put in communication each of the second and sixth orifices with the outside of the enclosure.

Therefore, in this configuration of the figure 3b it is possible to inject an inerting gas through the through passage 70 of the second movable member 60, which gas is then conducted to the inside of the storage space 22 by borrowing the sixth orifice 30f, the connecting pipe 56, the fifth orifice 30e, the passages 38, 34, and the first orifice 30a. The inerting gas can then be extracted from the internal storage space by the second fluid communication, to enter the chamber 12, and to extract from the second orifice 30b and the passage 68, and finally to be recovered outside the enclosure.

In this third preferred embodiment, the open position of the first movable member 36 is identical to that encountered in the second preferred embodiment. On the other hand, when this movable member 36 is moved by the operator in his closed position as shown on the Figures 3c and 3c ' it does not close the two orifices 30d, 30e it covers, but it ensures a communication of these two holes through a U-shaped inner passage 72 that it defines. It also prohibits the communication of each of these orifices 30d, 30e with the outside of the enclosure, so that the two fluidic communications are broken at this first movable actuating member 36.

The enclosure 12 is thus sealingly closed at the openings 30d, 30e by the first movable actuating member 36, which makes it possible to perform an inerting of this single enclosure. Indeed, it is possible to inject an inerting gas through the through passage 70 of the second movable member 60, the gas then borrowing the sixth orifice 30f, the connecting duct 56, the fifth orifice 30e, the inner passage in the form of U 72 of the member 36, and the fourth port 30d from which it can enter the enclosure. The inerting gas can then be extracted through the second orifice 30b and the passage 68, and finally be recovered outside the enclosure. Naturally, in this configuration of Figures 3c and 3c ' where the first movable member 36 is in the closed position, the canister 8 is mechanically disconnected from the structure 10, and can therefore be removed from the packaging device, as has been shown on the figure 3d .

In this figure, the second movable member 60 has been returned to the closed position, so that the enclosure 12 becomes sealed at the openings 30b, 30f, 30d, 30e of the structure 10.

It is possible to provide a second movable member 60 is assigned to each bottle 8 of the packaging device. However, for ease of handling and less space, it is alternatively possible to ensure that all the bottles 8 are associated with the same second movable member 60, as has been illustrated on the Figures 3e and 3f .

Here, each bottle is connected by its associated connecting pipe 56 to a sixth orifice 30f which is specific to it. On the other hand, there is only one and only one second orifice 30b associated with all the canisters, the sixth orifices 30f being for example arranged around this second orifice 30b. In addition, the structure 10 integrates a fixed wall extension 80, putting in permanent communication the whole sixth ports 30f through an annular groove 82 in which they open.

In the open position of the second movable member 60, shown on the figure 3e , the sixth orifices 30f are in communication with the outside of the enclosure by virtue of the alignment of the passage 70 of the member 60 with an outlet orifice 84 made in the extension 80 and opening into the annular groove 82 forming a collector . In addition, the passage 68 of the member 60 communicates the second single orifice 30b with the outside of the enclosure, by the alignment between the passage 68 and the extension 86 of the orifice 30b formed in the wall extension 80.

This configuration is that allowing the inerting of the bottles and the enclosure.

On the other hand, in the closed position of the second movable member 60, shown on the figure 3f , the U-shaped internal passage 62 ensures communication of each of the sixth orifices 30f with the second single orifice 30b, sealingly connecting the extension 86 of the orifice 30b, and the outlet orifice 84 opening into the annular groove 82 associated with the sixth holes 30f.

In addition, the movable member 60 prohibits the communication of each of the second single orifice 30b and the sixth holes 30f with the outside of the enclosure.

Whatever the preferred embodiment envisaged, the first orifice 30a can be realized differently, in a way shown on the Figures 4a and 4b .

On the figure 4a , it is shown part of an assembly 2a comprising the conditioning device 2 described above, with each bottle 8 housing in its internal storage space 22 a given volume of radioactive medium 90. The assembly 2a is shown in position vertical normal, where the axes of the bottles and the conditioning device 2 are substantially orthogonal to the support surface of the latter 92.

The given volume of radioactive medium 90 defines a level forming a horizontal demarcation 94 with a gaseous sky 96 completing the internal storage space 22.

Here, the first orifice 30a is initiated in the first closure piece 24, then extended in a conduit 98 projecting from the same piece 24 inside the internal storage space 22, close to a center of gravity. this last.

More precisely, the first orifice 30a is arranged in such a way that it is always in communication with the gaseous sky 96, whatever the orientation in the space of the canopy 8 integrating the given volume of medium 90. Thus, whatever or the position of the canopy 8, at least a portion of the open end of the first port 30a does not bathe in the medium 90, so that you can always allow the exhaust gases produced by radiolysis towards the enclosure.

Consequently, in the event of accidental conditions where the device would no longer be in the normal storage / storage position, such as that shown by way of example on the figure 4b , fluid communication between the gaseous surface 96 of the canister 8 and the enclosure remains preserved, thus avoiding the risk of sudden overshoot of the flammability threshold of the gases contained in the gaseous sky 96 of the canister.

As an indication, the maximum ratio between the given volume of medium and the total volume of the storage space in which it rests, may be of the order of 0.5.

Moreover, the ratio between the sum of the volumes of the storage spaces of all the bottles of the conditioning device, and the volume of the chamber, can be between 0.4 and 0.6.

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

Claims (18)

1. A packaging device (2) for the transport and/or storage of a radioactive medium generating flammable gases and/or explosives via radiolysis,
   the said device comprising at least one canister (8) intended to contain the radioactive medium (90), the said canister defining an inner storage space (22) accessible via an opening (20) for filling of the medium, on which plug-forming means (14) are mounted,
   characterized in that:

   the said device also comprises a structure (10) forming a chamber (12),

   and means for placing in communication allowing a first fluid communication (40) to be set up between the said inner storage space (22) and the said chamber (12).
2. The packaging device according to claim 1, characterized in that:

   the canister (8) further comprises a first orifice (30a) opening into the inner storage space (22),

   in that the said chamber-forming structure comprises a second orifice (30b) opening into the said chamber (12),

   and in that the said first and second orifices (30a, 30b) form the two opposite ends of the said first fluid communication (40).
3. The packaging device according to claim 2, characterized in that the said means for placing in communication comprise a first member (36) mobile between an open position in which it sets up the said first fluid communication (40), and a second closed position in which it shuts the said second orifice (30b), the said first mobile member (36) being mounted on the said chamber-forming structure (10).
4. The packaging device according to claim 2, characterized in that:

   the canister (8) further comprises a third (30c) opening into the inner storage space (22),

   in that the said chamber-forming structure comprises a fourth orifice (30d) opening into the said chamber (12),

   and in that the said means for placing in communication allow a second fluid communication (49) to be set up between the said inner storage space (22) and the said chamber (12), the said third and fourth orifices (30c, 30d) forming the two opposite ends of the said second fluid communication (49).
5. The packaging device according to claim 2, characterized in that:

   the canister (8) further comprises a third orifice (30c) opening into the inner storage space (22),

   in that the said chamber-forming structure comprises a fourth orifice (30d) opening into the said chamber (12),

   in that the said means for placing in communication allow a second fluid communication (49) to be set up between the said inner storage space (22) and the said chamber (12), the said third and fourth orifices (30c, 30d) forming the two opposite ends of the said second fluid communication (49),

   and in that a fifth and a sixth orifice (30e, 30f) are provided in the chamber-forming structure, and communicate with each other via a connecting duct (56) forming an integral part of the said means for placing in communication.
6. The packaging device according to claim 5, characterized in that the said means for placing in communication comprise a first mobile member (36) and a second mobile member (60) each mounted on the said structure (10) forming a chamber (12) and able to be moved between an open position and a closed position, the said first mobile member (36) being designed so that:

   - in open position, firstly it places in communication the said first orifice (30a) with the said fifth orifice (30e), and secondly it sets up the said second fluid communication (49) by placing in communication the said third orifice (30c) with the said fourth orifice (30d);

   - in closed position, firstly it ensures the placing in communication of the fourth orifice (30d) with the said fifth orifice (30e), and secondly it prohibits the communication of each of the fourth and fifth orifices (30d, 30e) with the outside of the said chamber,
   and in that the said second mobile member (60) is designed so that:

   - in open position, firstly it places in communication the said sixth orifice (30f) with the outside of the said chamber, and secondly it places the said second orifice (30b) in communication with the outside of the said chamber;

   - in closed position, firstly it ensures the placing in communication of the sixth orifice (30f) with the said second orifice (30b), and secondly it prohibits the communication of each of the second and sixth orifices (30b, 30f) with the outside of the said chamber.
7. The packaging device according to any of claims 3 to 6, characterized in that the said canister comprises an additional first mobile member (32), mobile between an open position in which it sets up the said first fluid communication (40), and a closed position in which it shuts the said first orifice (30a), either one of the first mobile member (36) and additional first mobile member (32) being a leading member and the other a follower member of the actuating member, so that the movement of the actuating member from its closed position to its open position leads the said follower member also to move from its closed position to its open position, and conversely.
8. The packaging device according to claim 7, characterized in that the said actuating member also forms a mechanical connection member for the said canister (8) on the chamber-forming structure.
9. The packaging device according to claim 8, characterized in that the said actuating member is designed so that its movement from its closed position to its open position, with the said canister (8) bearing upon the first mobile member (36), ensures a mechanical connection of the canister, and so that the movement from its open position to its closed position ensures mechanical disconnection of this canister.
10. The packaging device according to claim 9, characterized in that the said actuating member forms a male or female part of a bayonet mechanical connection.
11. The packaging device according to any of the preceding claims, characterized in that it comprises a plurality of canisters (8) each associated with means for placing in communication allowing a first fluid communication (40) to be set up between its inner space (22) and the said chamber (12).
12. The packaging device according to claim 11, combined with any of claims 5 to 10, characterized in that the means for placing in communication of all the canisters (8) share the same second orifice (30b),
    and in that the said second mobile member (60) is designed so that:

    in open position, firstly it places in communication each of the sixth orifices (30f) with the outside of the said chamber, and secondly it places the said single second orifice (30b) in communication with the outside of the said chamber;

    - in closed position, firstly it ensures the placing in communication of each of the sixth orifices (30f) with the said single second orifice (30b), and secondly it prohibits the communication of the single second orifice and of each of the sixth orifices (30b, 30f) with the outside of the said chamber.
13. An assembly (2a) comprising the said packaging device (2) according to any of the preceding claims, each canister (8) housing in its inner storage space a given volume of radioactive medium (90), defining a level forming a horizontal boundary line (94) with a gaseous headspace (96) completing this inner storage space, the said means for placing in communication associated with the said canister having a first orifice (30a) opening into the said inner storage space (22), and arranged so that at all times it is in communication with the gaseous headspace (96), irrespective of the spatial orientation of the said canister (8) integrating the said given volume of medium (90).
14. The assembly according to claim 13, characterized in that the said first orifice (30a) is provided at least in part in a duct (98) projecting inside the said inner storage space.
15. The assembly according to claim 14, characterized in that the said first orifice (30a) opens in the vicinity of a baric centre of the said inner storage space (22).
16. A package (1) for the transport and/or storage of a radioactive medium, characterized in that it comprises an overpack (6) forming a cavity inside which an assembly (2a) according to any of claims 13 to 15 is housed.
17. Container for the transport and/or storage of a radioactive medium, characterized in that it comprises an overpack (6) forming a cavity inside which a packaging device (2) according to any of claims 1 to 12 is housed.
18. A method for packaging a radioactive medium in a device according to any of claims 1 to 12, wherein:

    - the radioactive medium is introduced into the inner storage space of the canister;

    - the canister is sealed using plug-forming means; and

    - the said first fluid communication is set up between the said inner storage space and the said chamber.

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