EP1897094B1 - Device for controlling positioning of an assembly containing nuclear fuel in a housing of a storage basket - Google Patents

Abstract

The invention relates to a monitoring device (20) of the position of an assembly containing nuclear fuel (4) in a housing of a storage basket (2). According to the invention, it comprises at least one mobile stop device (24, 26, 28) and a position indicator (30) suitable for being held at a stop by the mobile stop device in a first position indicating that the assembly occupies a first position, said mobile stop device being arranged so as to be able to be placed, by means of contact with the assembly located in a second position in its housing, in a position enabling it to release the position indicator devised to move automatically from the first position to a second position indicating that the assembly occupies the second position.

Description

TECHNICAL AREA

The present invention relates generally to a device for controlling the positioning of an assembly containing nuclear fuel, in a housing of a storage basket.

It applies in particular to the control of the positioning of nuclear fuel assemblies or pencil boxes in their respective housings, these pencil boxes corresponding generally to metal cans in which are packaged nuclear fuel rods, intended for the manufacture of fuel assemblies.

The invention also relates to a locking system of an assembly containing nuclear fuel in a housing of a storage basket, the system ensuring an axial and lateral retention of the assembly in the housing, and being equipped with such a control device.

STATE OF THE PRIOR ART

During the transport of fresh nuclear fuel, for example of the "MOX" type, the packs used are arranged lying down, that is to say positioned horizontally, so that the nuclear fuel assemblies arranged inside the housing of the baskets rest by gravity on the side wall of their respective housings.

More precisely, in the case where the assemblies are nuclear fuel assemblies of rectangular parallelepipedal shape, two adjacent lateral surfaces of each assembly are respectively supported on two surfaces of the lateral wall of the housing concerned. This particular provision is essentially adopted in order to maintain the integrity of the fuel during transport.

In the prior art, it has been proposed to strengthen the maintenance of these assemblies by providing a locking system mounted at the upper end of each housing. Thus, this locking system not only allows to ensure a plating of the two side surfaces of the assembly against the side wall of the associated housing, but also ensures an axial clamping of this assembly in its housing.

Such a locking system is described in particular in the document FR-A-2,833,401 . As an indication, it is noted that this type of clamping system cooperates in such a way with the assembly that the latter is moved axially upwardly of the housing during the clamping operation, which implies that this assembly is more in contact with the bottom of the housing during transport, but in surface contact with the locking system. Free space between the bottom of the housing and the lower end of the assembly advantageously allows a non-risky differential expansion between these two elements.

If the addition of this blocking system thus makes it possible to reinforce the maintenance of the nuclear fuel assembly in its associated housing, and consequently to reduce the risks of deterioration of the fuel assemblies during transport, it is nonetheless noted that visual and manual access to the interior of the housing becomes extremely restricted once the locking system is put in place on the open end of the housing.

Thus, it remains very difficult for an operator to quickly know the actual positioning of the assembly within his housing, this disadvantage being all the more restrictive as the exposure time of an operator in a nuclearized medium must naturally be reduced to a minimum.

As a guide, we can mention various situations in which the operator should, even if this is currently impossible because of the presence of the blocking system station above the housing, can be able to easily and quickly control the positioning of the assembly.

This is obviously of course the case in which the loading operations of the assembly in its housing and tightening of the locking system have just been performed. The operator should be able to ensure that the assembly occupies a good position within its housing, that is to say a positioning allowing the transport of the packaging. As is apparent from the above, it should then be possible to control the correct positioning of each of the two adjacent side faces of the assembly intended to be in contact with the side wall of the housing, as well as the positioning of the upper end intended to be in surface contact with the blocking system.

Another situation in which the operator would benefit from being quickly and easily informed of the actual positioning of the assembly within his housing concerns the moment following the loosening of the locking system. Indeed, after transporting the packaging and before removing the locking system, the operator should be able to ensure that the fuel assembly occupies a position allowing its unloading of the housing, namely a positioning that can also be qualified of "unlocked", and translating on the one hand the fact that the locking system has been sufficiently loosened to be removed from the housing without risk of damage to the assembly, and secondly the fact that it is well income in support in the bottom of housing, or in a position very close to the same bottom.

As is apparent from the above, since the loosening of the locking system has the consequence, in some embodiments, of causing axial movement of the assembly towards the bottom of the housing to cause a deposit of this assembly. in the bottom of the housing, it would then be enough to be able to control the axial positioning of this same assembly.

STATEMENT OF THE INVENTION

The object of the invention is therefore to propose a device for controlling the positioning of an assembly containing nuclear fuel in a housing of a storage basket, as well as a system for blocking an assembly integrating such a control device. , so as to at least partially overcome the disadvantages mentioned above relating to the embodiments of the prior art.

To do this, the object of the invention is a device for controlling the positioning of an assembly containing nuclear fuel in a housing of a storage basket, comprising at least one mobile stop member and a positioning indicator suitable for to be held in abutment by the movable abutment member in a first position indicating that the assembly occupies a first positioning, this movable abutment member being arranged so as to be brought into contact with the assembly situated in a second position; positioning within its housing, in a position to release the positioning indicator adapted to move automatically from the first position to a second position indicating that the set occupies the second position.

Advantageously, these control devices of simple and clever design makes it possible to inform the operator quickly and unambiguously on the position of the assembly within his dwelling, without that it is necessary to have visual or manual access inside the same dwelling. Indeed, the positioning indicator can easily be reported outside the housing concerned, such as on the storage basket, or even more preferably on the locking system equipping the upper part of this housing. This indicator is then produced so as to generate clear information for the operator, such as all-or-nothing information.

It is also noted that the consequence resulting from the presence of such a device for each housing of a basket is that the exposure time of the operator in the nuclearized medium during the loading and unloading of the assemblies can advantageously be substantially reduced.

Preferably, the device is designed so that said first positioning of the assembly corresponds to a positioning prohibiting transport and so that the first position of the indicator corresponds to a position indicating position prohibiting the transport, and designed so that the second positioning of the assembly corresponds to a positioning allowing transport and so that the second position of the indicator corresponds to a position indicating position allowing transport.

In such a case, it must therefore be understood that the control device generally makes it possible to indicate to the operator, following the loading of the assembly into its housing and after the tightening of the blocking system, whether or not this assembly occupies a good position within its housing, that is to say a satisfactory position for safe subsequent transport of the packaging. As will be detailed below, it is noted that the positioning allowing transport is obtained when the assembly has established all the required contacts with the housing and the locking system, when such a system has been provided.

It can also be provided that the positioning indicator is furthermore capable of being held in abutment by at least one movable abutment member in the position indicating position allowing transport, this movable abutment member being arranged in such a way as to be able to being brought into contact with the assembly located in a position allowing it to be unloaded from the housing, in a position enabling it to release the indicator designed to move automatically from the position indicating position allowing the transport to a position d positioning indication allowing the unloading of the assembly.

Thus, in this configuration allowing the control device to indicate a third position, the operator can then be informed, before unloading the assembly and after loosening of the locking system, whether or not this assembly occupies a position allowing a non-risky extraction of the locking system, this extraction must necessarily be performed prior to unloading the assembly. As will be detailed below, it can be provided that the positioning allowing the unloading of the assembly is obtained when the assembly has been redeposited in the bottom of the housing or brought close to it, following the loosening of the locking system.

In addition, it is preferably provided that the indicator is held abutting in the position indicating position allowing transport by a single movable stop member, preferably one of those already used to maintain this indicator in the position indicating position prohibiting transport.

Alternatively, the control device may be designed so that the first positioning of the assembly corresponds to a positioning prohibiting the unloading of the assembly and so that the first position of the indicator corresponds to a position indicating position. prohibiting the unloading of the assembly, and designed so that the second positioning of the assembly corresponds to a positioning allowing its unloading of the housing and so that the second position of the indicator corresponds to a position indicating position allowing the unloading of the whole.

In this case where the device is not intended to provide information on the positioning of the assembly before the transport of the package, but generally only designed to control the redeposition of the assembly at the bottom of the housing after loosening the system blocking, we can therefore provide control only the axial positioning of the assembly with this device, for example using a single movable abutment member, such as an axial pusher. As an indication, it is noted that the passage of all the positioning prohibiting the unloading to the positioning allowing the unloading is identical or similar to the passage mentioned above of the positioning authorizing the transport to the positioning allowing the unloading, since in both cases , the set goes from a state in which it is removed from the bottom of the housing to a state in which it is in contact with the same bottom or very close to the latter.

Preferably, the device comprises a plurality of movable abutment members, each adapted to abut the positioning indicator in the first position. In addition, as mentioned above, it can also be provided that at least one of these organs is able to hold the indicator in at least one other position among those indicated above.

The device then comprises a first movable abutment member arranged to move in translation in a first direction, this first member then preferably taking the form of a pusher provided with a groove cooperating with a groove formed in the positioning indicator .

According to a first preferred embodiment of the present invention, the device further comprises a second mobile stop member and a third mobile stop member. respectively arranged to pivot about a second direction and a third direction, the first, second and third directions being orthogonal to each other.

Thus, the three proposed members make it possible to control the positioning of three orthogonal surfaces of the assembly, by contact with them, this solution being of course sought in order to control the positioning of rectangular parallelepiped-shaped assemblies, such as that observed on nuclear fuel assemblies and pencil boxes. Naturally, the invention also applies to the control of the overall positioning having a different shape, the number and the design of the movable abutment members then being chosen as a function of the number and the arrangement of the surfaces of the assembly to be controlled. .

Preferably, the first, second and third movable abutment members are equipped with elastic return means, which preferably all tend to return their associated movable member to a position where the latter constitutes a stop for the indicator.

According to a second preferred embodiment of the present invention, the control device no longer integrates the second and third aforementioned members, but includes a fourth movable stop member arranged to move in translation in the first direction, this fourth movable member. stop having a frustoconical contact end with an axis parallel to the first direction.

Thus, this frustoconical contact end makes it possible to control the positioning of two surfaces of the orthogonal assembly with each other and parallel to the first direction, whereas the first member makes it possible to control the positioning of a third surface of this set, orthogonal to the other two. The second preferred embodiment, in which the fourth movable abutment member is equipped with elastic return means, is therefore also especially well suited for controlling the positioning of rectangular parallelepiped-shaped assemblies, but could naturally find an application for assemblies. having other forms.

On the other hand, the positioning indicator takes the form of a flap equipped with elastic return means allowing its automatic movement from the first position to the second position.

Finally, the invention also relates to a locking system of an assembly containing nuclear fuel in a housing of a storage basket, this system providing axial and lateral retention of the assembly in its housing, and being equipped a control device such as that described above and also object of the present invention. As indicated above, the lateral support is preferably performed by plating at least two surfaces of the assembly against the associated housing, and preferably two orthogonal surfaces between them.

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 schématique et partielle en coupe d'un logement d'un panier de rangement dans lequel se situe un assemblage de combustible nucléaire, le logement étant équipé d'un système de blocage selon la présente invention, montré dans une configuration de serrage dans laquelle il bloque l'assemblage au sein de son logement ;
• la figure 2 représente une vue en coupe prise le long de la ligne II-II de la figure 1 ;
• la figure 3 représente une vue partielle en perspective du système de blocage, celui-ci comprenant un dispositif de contrôle du positionnement de l'assemblage de combustible dans son logement selon un premier mode de réalisation préféré de la présente invention, ce dispositif de contrôle se trouvant dans une configuration dans laquelle le positionnement de l'assemblage au sein de son logement est tel que le transport est interdit ;
• la figure 4a montre une vue partielle en coupe montrant plus spécifiquement le premier organe mobile de butée du dispositif montré sur la figure 3 ;
• la figure 4b montre une vue similaire à celle de la figure 4a, dans une configuration dans laquelle le positionnement axial de l'assemblage au sein de son logement est satisfaisant ;
• la figure 5a montre une vue partielle en coupe montrant plus spécifiquement le second organe mobile de butée du dispositif montré sur la figure 3 ;
• la figure 5b montre une vue similaire à celle de la figure 5a, dans une configuration dans laquelle le positionnement latéral de l'assemblage au sein de son logement est satisfaisant ;
• la figure 6 représente une vue similaire à celle montrée sur la figure 3, le dispositif de contrôle se trouvant dans une configuration rencontrée lors du déplacement automatique de son indicateur de positionnement entre la position d'indication de positionnement interdisant le transport, et la position d'indication de positionnement autorisant le transport
• la figure 7 représente une vue similaire à celle montrée sur la figure 3, le dispositif de contrôle se trouvant dans une configuration dans laquelle le positionnement de l'assemblage au sein de son logement est tel que le transport est autorisé ;
• la figure 8 représente une vue de dessus de la figure 7 ;
• la figure 9 représente une vue similaire à celle montrée sur la figure 3, le dispositif de contrôle se trouvant dans une configuration dans laquelle le positionnement de l'assemblage au sein de son logement est tel que son déchargement est autorisé ;
• la figure 10 représente une vue partielle en perspective du système de blocage, celui-ci comprenant un dispositif de contrôle du positionnement de l'assemblage de combustible dans son logement selon un second mode de réalisation préféré de la présente invention, ce dispositif de contrôle se trouvant dans une configuration dans laquelle le positionnement de l'assemblage au sein de son logement est tel que le transport est interdit ;
• la figure 11a montre une vue partielle en coupe du dispositif de contrôle montré sur la figure 10 ;
• la figure 11b montre une vue similaire à celle de la figure 11a, dans une configuration dans laquelle le positionnement axial de l'assemblage au sein de son logement est satisfaisant ;
• la figure 11c montre une vue similaire à celle de la figure 11b, dans une configuration dans laquelle le positionnement latéral de l'assemblage au sein de son logement est satisfaisant ; et
• la figure 12 représente une vue similaire à celle montrée sur la figure 10, le dispositif de contrôle se trouvant dans une configuration dans laquelle le positionnement de l'assemblage au sein de son logement est tel que le transport est autorisé.

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

• the figure 1 is a schematic and partial sectional view of a housing of a storage basket in which is located a nuclear fuel assembly, the housing being equipped with a locking system according to the present invention, shown in a clamping configuration in which blocks the assembly within its housing;
• the figure 2 represents a sectional view taken along line II-II of the figure 1 ;
• the figure 3 is a partial perspective view of the locking system, which comprises a device for controlling the positioning of the fuel assembly in its housing according to a first preferred embodiment of the present invention, this control device being in a configuration in which the positioning of the assembly within its housing is such that transport is prohibited;
• the figure 4a shows a partial sectional view showing more specifically the first movable abutment member of the device shown in FIG. figure 3 ;
• the figure 4b shows a view similar to that of the figure 4a , in a configuration in which the axial positioning of the assembly within its housing is satisfactory;
• the figure 5a shows a partial sectional view showing more specifically the second mobile abutment member of the device shown in FIG. figure 3 ;
• the figure 5b shows a view similar to that of the figure 5a in a configuration in which the lateral positioning of the assembly within its housing is satisfactory;
• the figure 6 represents a view similar to that shown on the figure 3 , the control device being in a configuration encountered during the automatic movement of its positioning indicator between the position indicating position prohibiting the transport, and the position indicating position allowing the transport
• the figure 7 represents a view similar to that shown on the figure 3 the control device being in a configuration in which the positioning of the assembly within its housing is such that transport is permitted;
• the figure 8 represents a top view of the figure 7 ;
• the figure 9 represents a view similar to that shown on the figure 3 , the control device being in a configuration in which the positioning of the assembly within its housing is such that its unloading is authorized;
• the figure 10 is a partial perspective view of the locking system, the latter comprising a device for controlling the positioning of the fuel assembly in its housing according to a second preferred embodiment of the present invention, this control device being in a configuration in which the positioning of the assembly within its housing is such that transport is prohibited;
• the figure 11a shows a partial sectional view of the control device shown on the figure 10 ;
• the figure 11b shows a view similar to that of the figure 11a in a configuration in which the axial positioning of the assembly within its housing is satisfactory;
• the figure 11c shows a view similar to that of the figure 11b in a configuration in which the lateral positioning of the assembly within its housing is satisfactory; and
• the figure 12 represents a view similar to that shown on the figure 10 , the control device being in a configuration in which the positioning of the assembly within its housing is such that the transport is authorized.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

With reference to the figure 1 it is possible to see a housing 1 of a storage basket 2, in which a nuclear fuel assembly 4 is located. As an indication, it is noted that one or more dwellings 1 can be arranged in the basket 2 intended to be arranged in a package (not shown), without departing from the scope of the invention.

Each housing 1 is sized to receive a single assembly 4. For this purpose, the internal dimensions of the housing 1 are slightly greater than those of the assembly 4, as is clearly visible on the figure 1 . In addition, the fuel assemblies 4 and the housings 1 generally have polygonal complementary sections, most often square, as schematically illustrated by FIG. figure 2 .

The housing 1 is equipped at its upper open part with a locking system 6 according to the present invention, shown only schematically and in a clamping configuration in which it blocks the assembly 4 within its housing 1, which has previously introduced in the latter.

The tightening effected by means of the system 6 makes it possible to secure the assembly 4 in the axial direction 8 of the housing 1, by surface contact, preferably plane, between an upper end piece 11 of the assembly and this same locking system, and more preferably between a horizontal upper surface 9 of the upper nozzle 11 and the locking system. In a manner known to those skilled in the art, the clamping operation has the effect of taking off the lower nozzle 10 of the bottom assembly 12 of the housing 1, as can be seen on the figure 1 which allows the differential expansion between the two elements.

In addition, in the usual case where the assembly 4 has a square section, the tightening taking place at the upper end 11 of the assembly 4 also results in the plating of two side faces. 14a, 14b of this assembly 4 against respectively two adjacent side surfaces 16a, 16b of the side wall of the housing 1, as can be seen schematically on the figure 2 . In addition, it is noted that this blocking, referred to as lateral blocking, is jointly ensured during the transportation of the assemblies 4 by the specific position of the packaging, said lying or horizontal. In this position represented on the figure 2 the axial direction 8 of the housing 1 is then parallel to the ground, and the edge 18 joining the two orthogonal lateral surfaces 16a, 16b corresponds to the lowest part of the housing 1, so that these two surfaces 16a, 16b form jointly an open V upwards. Therefore, the two surfaces 14a, 14b of the assembly 4 tend, under the effect of gravity, respectively to bear against the surfaces 16a, 16b during transport. As previously indicated, the biplane side contact is sought to preserve the integrity of the fuel during transport. It is nevertheless recalled that during the loading and unloading of the assemblies 4, the packaging is generally oriented so that the longitudinal axis 19 of each housing 1, parallel to the direction 8, is substantially vertical.

The design of the locking system 6, and more specifically that of its means allowing to ensure the three blockages indicated above, corresponds to a design known to those skilled in the art, and therefore will not be further described. As indicative examples, this blocking system 6 intended to minimize the movements of the assembly 4 during transport can take any of the forms described in the document FR-A-2,833,401 . In these various forms, the system mainly comprises a fixing device designed to achieve a rigid connection between the upper end of the assembly, and the open end of the housing.

As will now be described, the specificity of this system 6 lies in the fact that it incorporates a device for controlling the positioning of the assembly in the housing concerned.

Firstly with reference to the figure 3 representing a control device 20 according to a first preferred embodiment of the present invention and equipping the locking system 6, it can be seen that this device 20 is preferably located at an angle of the system 6 of substantially square section (1 end of the angle at which the device 20 has been deliberately omitted for the sake of clarity). It should be understood here that the main plate 22 of the system 6, which substantially closes the open end of the housing 1 and which is also called the closure flange, serves as mounting support for the control device 20.

On this figure 3 , the device 20 is shown in a configuration in which the positioning of the assembly 4 within its housing 1 is such that the transport is prohibited, this state being met in particular when the assembly 4 has just been loaded into the housing 1 but that the tightening of the locking system 6 was not operated, or when the tightening was performed but the assembly 4 occupies, due to any anomaly, a different end position than required. Moreover, this state can also be met before the loading of the assembly 4 in the housing 1.

As an indication, the figure 3 partially shows the assembly 4 in a position corresponding to that occupied directly after the loading thereof and before tightening the system 6, in which position it rests at the bottom of the housing 1.

As will be explained below, the control device 20 is preferably designed to control the axial positioning of the assembly, as well as its lateral positioning in two distinct directions, which are here orthogonal because of the orthogonality between the two side surfaces 14a, 14b whose contact with the wall of the housing 1 is to be controlled.

To do this, it comprises three movable abutment members 24, 26, 28, which, when the assembly 4 occupies a position prohibiting transport within its housing, each retaining by a stop positioning indicator 30 in a position indicating position prohibiting transport.

This positioning indicator 30 may be made in any way known to those skilled in the art, by combining it with a marking made on a support of the indicator which is here the plate 22, this marking may for example take the form of a graduation, a color code, and more generally any form allowing the operator to visually determine the position of the indicator, and therefore that of the assembly within the housing. By way of indicative example, in the first preferred embodiment shown in the figures, the indicator takes the form of a flap 30 attached externally hingedly to the main plate 22 serving as a support, along a pivot 31 parallel to the axial direction 8. In this positioning position prohibiting the transport, its angular position relative to the plate 22 is such that it discovers a first zone 34 of a marking, this zone 34 being formed on the upper surface of this plate 22 and made to indicate clearly and accurately to the operator that the assembly 4 is poorly positioned in the housing 1 to which it no longer has visual access. This first zone 34 may for example take on a particular color, belonging to a color code known to the operator.

More particularly with reference to the figure 4a showing the first movable thrust member 24, we can see that it takes the form of a pusher oriented in the direction 8 and a lower end 38 is close to the tip of square section 11 of the assembly resting in the bottom of the housing 1.

At this stage, the locking system 6 has only been put in place on the upper part of the housing 1 with which it is in contact, but it has not yet been tightened. This is the reason why the assembly 4 occupies an axial positioning prohibiting the transport, which results in the absence of contact between the upper surface 9 of the nozzle 11 and a lower horizontal surface 36 of the plate 22, these two surfaces 9, 36 then being oriented perpendicular to the direction 8.

The axial pusher 24 is therefore in its lowest position provided by elastic return means preferably taking the form of a compression spring 40 interposed between the plate 22 and the lower end 38, and by a shoulder 42. limiting the stroke of this pusher 24 downwards by its support against a seat 44 formed in an upper portion of the plate 22. In this position, the lower end 38 and the upper surface 9 are preferably spaced apart from one set 46. On the other hand, an upper end 50 of this pusher 24 is housed in a through orifice 52 of the flap 30, the orifice 52 and the end 50 having a substantially identical diameter.

It is therefore the abutment between these two elements 50 and 52 which makes it possible to maintain the shutter 30 in the position indicating position prohibiting the transport shown on the figure 3 . Indeed, without this stop, the flap 30 would be rotated about the axis 60 of the pivot 31 by means of elastic return means preferably taking the form of a torsion spring 54 arranged around the pivot 31, itself through the flap 30 and being arranged in the direction 8. Here, the spring 54 has a lower end secured to the plate 22 and an upper end secured to the flap 30.

Referring now to the figure 4b partially showing the device 20 in a configuration in which the axial positioning of the assembly 4 within its housing 1 is satisfactory, it can indeed be seen that this assembly has been sufficiently tightened by the locking system 6 to generate a plating of the surface 9 of the upper nozzle 11 against the lower surface 36 of the plate 22.

During this tightening, the upward movement of the assembly 4 in the housing 1 has the effect of bringing into contact the surface 9 and the lower end 38 of the pusher 24. Consequently, the tip 11 exerts an action on the pusher 24 which then moves upwardly compressing the spring 40, until the surfaces 9 and 36 abut, as shown in FIG. figure 4b . In this position, it can be seen that the pusher 24 has been moved sufficiently upwards so that its end 50 is entirely extracted from the orifice 52, which is now facing a groove 56 of this same pusher, and located below the end 50.

The diameter of this groove 56 is substantially identical to the width of a groove 58 (visible on the figure 3 ) taking the form of a circular arc centered on the axis 60 of the pivot 31, and opening into the hole 52 above. Thus, in this state, the pusher 24 no longer holds the shutter 30 in abutment, since a pivoting thereof along the axis 60 would have the effect of causing engagement of the circular groove 58 in the groove 56, then relative sliding between these two elements 56, 58.

Now with reference to figure 5a showing the second movable abutment member 26, it can be seen that it takes the form of an arm arranged articulated about a pivot 64 extending in a second direction 62 orthogonal to the direction 8, this direction 62 being also parallel to the surface 16a of the housing 1.

At this stage, the locking system 6 has only been put in place on the upper part of the housing 1 with which it is in contact, but it has not yet been tightened. This is the reason why the assembly 4 occupies a lateral positioning prohibiting the transport, which results in the absence of contact between the lateral surface 14a of the assembly and the lateral surface 16a of the housing.

The arm 26 is therefore in a position where its lower end projects more protruding inside the housing 1, through the surface 16a, this position being maintained by default by by means of elastic return means such as a torsion spring 68 shown only schematically and being arranged around the pivot 64, so in the second direction 62. Here, the spring 68 has an end secured to the arm 26, and at another end integral with the plate 22. Thus, as is also the case for the spring 40 associated with the pusher 24, the spring 68 has the effect of keeping the arm 26 in an abutment position for the flap 30.

In this state maintained by the abutment between the surface 36 of the plate 22 and the lower end 66 of the arm 26, the arm 26 thus rests in a substantially tilted position in which it deviates from the housing by going upwards.

On the other hand, an upper end 72 of this arm 26, also called abutment end, is housed in a straight groove 74 of the flap 30, this groove 74 opening radially outwardly of this flap 30 and being formed on a surface bottom of it. More specifically, the groove 74 is made in the same plane as the plane of movement of the arm 26, that is to say in a plane parallel to the direction 8 and orthogonal to the direction 62.

Here again, it is therefore the abutment between these two elements 72, 74 which makes it possible to maintain the shutter 30 in the position indicating position prohibiting the transport shown on FIG. figure 3 . Indeed, without this stop, the flap 30 would be rotated about the axis 60 of the pivot 31 by means of the torsion spring 54 already described.

Referring now to the figure 5b partially showing the device 20 in a configuration in which the lateral positioning of the assembly 4 within its housing 1 is satisfactory, it can indeed be seen that this assembly has been sufficiently tightened by the locking system 6 to generate a plating of the lateral surface 14a of the assembly 4 against the lateral surface 16a of the housing 1.

During this tightening, the lateral movement of the assembly 4 in the housing 1, in the direction of the surface 16a, has the effect of bringing the surface 14a and the lower end 66 of the arm 26 into contact. Therefore, the surface 14a exerts an action on the arm 26 which then pivots about the pivot 64 in the second direction 62 by compressing the spring 68, until the surfaces 14a, 16a abut, as shown in FIG. figure 5b . In this position where the upper end 72 of the arm 26 has been returned to the housing 1 and the lower end 66 pushed out of the same housing, it can be seen that the end 72 has been moved enough to be fully extracted from the groove 74. Indeed, the upper abutment end 72 is now in a free space 78 formed at the lower surface of the flap 30, this space 78 being arranged radially further inwards with respect to the groove 74.

Thus, in this state, the arm 26 no longer retains the shutter 30 in abutment, since a pivoting thereof along the axis 60 would have the consequence to generate a relative displacement between the free space 78 and the end 72 located therein.

With reference again to the figure 3 it can be seen that the design of the third movable abutment member 28 is identical to that of the second just described, and therefore it will not be more detailed. This third member 28 is, however, provided to control the contact between the surfaces 14b and 16b, and its pivoting arm is thus arranged to be able to be rotated in a third direction 79 orthogonal to the first and second directions 8 and 62. It is noted that when the contact is established between these two lateral surfaces 14b, 16b, the upper end of the arm 28 also integrates the free space 78 after having been extracted from its associated groove.

At the end of the clamping of the locking system 6, the three movable abutment members 24, 26, 28 are normally simultaneously positioned in the states shown respectively on the Figures 4b and 5b in which they no longer retain the shutter 30 in abutment, the order of obtaining these three satisfactory states can be any. From this moment only, the free flap 30 is only subjected to the action of the torsion spring 54 which causes a pivoting of the latter around the axis 60, during which the groove 56 therefore slides in the circular groove 58 as shows it figure 6 .

Together with reference to figures 7 and 8 showing the control device 20 being in a configuration in which the positioning the assembly within its housing is such that transport is allowed, it can be seen that the flap 30 has been moved automatically under the effect of the spring 54 is stopped in a precise angular position by a stop between the upper end 50 of the pusher 24, and a tongue 80 situated above the through groove 58, on the upper surface of the flap 30. More specifically, this tongue 80 is arranged above an outlet section 82 of the groove 58, this section 82 being opposite to the end of the groove opening into the orifice 52, and having a width greater than that of the remainder of this groove.

In this position indicating position allowing transport, the angular position of the flap 30 relative to the plate 22 is such that it covers the first zone 34 of the marking, which clearly and accurately indicates to the operator that the assembly 4 is correctly positioned in the housing 1 to which it no longer has visual access. In this preferred example of marking, it has in fact been provided that during occupation by the flap 30 of the position indicating position allowing transport, no area of this marking is apparent.

The device 20 is also designed, in this first preferred embodiment, so that the flap 30 can occupy a third position qualified positioning position position allowing the unloading of the assembly. In fact, in this third position, the operator can then be informed, before the unloading of the assembly 4 and after loosening of the locking system 6, whether or not this assembly occupies a position allowing non-risky extraction of the locking system 6. It can then preferably be provided that the positioning authorizing the unloading of the assembly is obtained when the assembly 4 has been redeposited in the bottom of the housing or brought close to it, following the loosening of the locking system 6.

Indeed, during this loosening, the assembly 4 is brought down the housing 4, and the pusher 24 constituting the only stop member to retain the flap 30 therefore follows the movement of this assembly, under the effect of compression spring 40 decompressing. This pusher 24 therefore gradually descends towards the position shown on the figure 4a , implying that its upper end 50 is lowered below the tongue 80 by penetrating into the outlet section 82 (shown in FIG. figure 9 ) of the groove 58 whose width is greater than or equal to the diameter of this end 50. Thus, in this state where the upper end 50 is entirely located below the tongue 80 and where the pusher 24 is again abutted against the seat 44, this pusher no longer retains the flap 30 in abutment, since a pivoting thereof along the axis 60 would have the effect of causing a relative sliding between the outlet section 82 of the groove 58, and the end 50 located within it.

Therefore, the flap 30 can then automatically join the indication position of positioning allowing unloading of the assembly as shown on the figure 9 under the simple action of the spring 54. In this position indicating position allowing unloading, the angular position of the flap 30 relative to the plate 22 is such that it discovers a second zone 84 of the marking and that it continues to cover the first zone 34, this second zone 84 being also made on the upper surface of this plate 22 and made to indicate clearly and accurately to the operator that the assembly 4 is well positioned in the bottom of the housing 1 or near the latter. This second zone 84 preferably takes on a color different from that of the first zone 34. Moreover, this third position is then retained by abutment between the flap 30 and a pin 86 provided on the upper surface of the flap 30.

As a guide, it is noted that to avoid problems of hyperstatism, the automatic transition between the second and the third position of the flap 30 preferably takes place not at the end of the loosening, but just before the end of this loosening. 6. Consequently, after the aforementioned passage of the flap 30 of the second to the third position, the operator must complete the loosening to finish depositing the assembly in the bottom of the housing 1, the lowering generated n being, however, only very weak and substantially corresponding to the game 46 shown on the figure 4a .

Once these operations have been completed, the operator can then remove the locking system 6 and extract the assembly 4 from its housing 1. In addition, the control device 20 can then be rearmed manually for future transport of assembly in the housing concerned.

Referring now to the figure 10 , a control device 20 may be seen according to a second preferred embodiment of the invention, this device equipping the locking system 6 also object of the present invention. It is noted that this embodiment has similarities with the previous one, and that the elements bearing the same numerical references in the figures correspond to identical or similar elements.

Moreover, this device will be described as being able only to detect two distinct positioning of the assembly within its housing, namely that prohibiting the transport and that authorizing the transport of this assembly. Nevertheless, it is obvious that it could be adapted by those skilled in the art, in view of the first preferred embodiment described above, to also detect a third positioning corresponding to the positioning allowing unloading of the assembly.

Overall, this second embodiment differs from the first in that the two lateral arms 26 and 28 are replaced by a fourth movable stop member in the form of a pusher adapted for check the lateral positioning of the assembly in the housing.

More precisely, as can be seen on the figure 10 showing the device 20 in a configuration in which the positioning of the assembly (not shown) within its housing is such that transport is prohibited, this device 20 is also located at the periphery of the system 6 of substantially circular section and integrating a main plate 22 for closing the open end of the housing.

As will be explained hereinafter, the control device 20 is preferably designed to control the axial positioning of the assembly, as well as its lateral positioning in a plane orthogonal to the axial direction 8. Thus, the lateral positioning control performed, comparable to a lateral control in two directions, for example orthogonal to each other as was the case in the first preferred embodiment, is obviously associated with the two side surfaces 14a, 14b of the assembly 4 whose contact with the housing wall is to be controlled. Therefore, this device 20 is very well adapted to control the contact of three orthogonal surfaces of the assembly 4, respectively with the clamping system 6 and the side wall of the housing.

To do this, it comprises a first movable abutment member 124 and a fourth movable abutment member 90, which, when the assembly 4 occupies a position prohibiting transport within its housing, retain by stop the flap 30 in the positioning position prohibiting the transport position, this flap 30 being here also articulated about the axis pivot pin 60 parallel to the direction 8. In this positioning position position prohibiting the transport, the angular position of the flap 30 relative to the plate 22 is such that it discovers the first zone 34 of the marking made to indicate clearly and accurately to the operator that the assembly 4 is incorrectly positioned in the accommodation.

With reference to the figure 11a further showing the first movable abutment member 124, it can be seen that it takes the form of a pusher oriented in the direction 8 and a lower end 138 is close to the tip 11 of the assembly resting in the bottom of the housing 1. At this stage, the locking system 6 has only been put in place on the upper part of the housing 1 with which it is in contact, but it has not yet been tightened. This is the reason why the assembly 4 occupies an axial positioning prohibiting the transport, which results in the absence of contact between the upper surface 9 and the lower horizontal surface 36 of the plate 22.

The axial pusher 124 is thus in its lowest position provided by elastic return means preferably taking the form of a compression spring 140 interposed between a hollow body 92 of the device 20 and the lower end 138, the elements 124, 140 and 92 being concentric. On the other hand, the lowest position is maintained thanks to a stop between a shoulder 142 of the pusher 124, which can be formed by a ring, and an upper end 94 of the hollow body 92 secured to the plate 22, this stop limiting effectively the stroke of the pusher 124 down. In this position, the lower end 138 and the upper surface 9 are spaced apart by a clearance 46. On the other hand, an upper end 150 of this pusher 124 is housed in a through orifice 52 of the flap 30, the orifice 52 and the end 150 having a substantially identical diameter.

It is therefore the abutment between these two elements 150 and 52 which makes it possible to keep the shutter 30 in the position indicating position prohibiting the transport shown on FIG. figure 10 . Indeed, without this stop, the flap 30 would be rotated about the axis 60 of the pivot 31 via the torsion spring 54 whose lower end is secured to the plate 22, and whose upper end in solidarity with shutter 30.

Referring now to the figure 11b showing the device 20 in a configuration in which the axial positioning of the assembly 4 within its housing 1 is satisfactory, it can indeed be seen that this assembly has been sufficiently tightened by the locking system 6 to generate a plating of the surface 9 of the upper nozzle 11 against the lower surface 36 of the plate 22.

During this tightening, the upward movement of the assembly 4 in the housing 1 has the effect of bringing into contact the surface 9 and the lower end 138 of the pusher 124. Therefore, the tip 11 exerts an action on the pusher 124 which then moves upwardly compressing the spring 140, until the surfaces 9 and 36 abut, as shown in FIG. figure 11b . In this position, it can be seen that the pusher 124 has been moved sufficiently upwards so that its end 150 is entirely extracted from the orifice 52, which is now facing a groove 156 of this same pusher, and located below the end 150.

The diameter of this groove 156 is substantially identical to the width of the groove 58 (visible on the figure 10 ) taking the form of a circular arc centered on the axis 60 of the pivot 31, and opening into the hole 52 above. Thus, in this state, the pusher 124 no longer retains the shutter 30 in abutment, since a pivoting thereof along the axis 60 would have the consequence of causing engagement of the circular groove 58 in the groove 156, then a relative sliding between these two elements 156, 58. Moreover, it can naturally be seen that there is no longer a stop between the elements 142 and 94, the entire pusher 124 arranged inside the body hollow 92 having been moved upwards in the axial direction 8.

Again with reference to figure 11a showing the fourth movable stop member 90, can see that it also takes the form of a pusher oriented in the direction 8 and a lower end 96 is close to the tip 11 of the assembly resting in the bottom of the housing 1. This end 96 of frustoconical shape axis 100 parallel to the direction 8 is also called contact end, since it is intended to be housed in a hole 98 of complementary shape, provided on the nozzle 11 of the assembly. On the other hand, as can clearly be seen on this figure 11a , the pusher 90 is arranged concentrically with respect to the elements 124 and 92, and passes through the pusher 124.

At this stage where the locking system 6 has not yet been tightened, the assembly 4 occupies a lateral positioning prohibiting the transport, which results in the absence of contact between the lateral surface 14a of the assembly and the surface 16a side of the housing, and between the side surface 14b of the assembly and the side surface 16b of the same housing (the surfaces 14b and 16b are not visible on this figure 11a ).

The pusher 90 is then in its lowest position provided by elastic return means preferably taking the form of a compression spring 102 interposed between the hollow body 92 and a spacer 104 bearing against an upper portion of a rod 106 orthogonally crossing the pusher 90. On the other hand, the lowest position is maintained thanks to a stop between the two ends of this rod 106 and the bottom of two lights 110 made in faces side of the hollow body 92, this stop thus limiting the stroke of the pusher 90 downwards. In this position, the lower end 96 and the upper surface 9 are for example in contact with each other, or very close together, which implies that the end 96 projects slightly from the end 138 towards the low. On the other hand, an upper end 112 of this pusher 90 projects upwardly from the upper end 150 of the pusher 124.

With reference to the figure 11b showing the device 20 in a configuration in which the axial positioning of the assembly within its housing is satisfactory but in which the lateral positioning of the assembly within its housing is such that transport is still prohibited, one can see that the reassembly of the assembly 4 in the housing 1 has not only caused an upward movement of the pusher 124, but also an upward displacement of the concentric pusher 90, because of the contact of the end 96 with the endpiece 11. In this position authorized by the compression of the spring 102 and the displacement of the rod 106 in the slots 110 oriented in the direction 8, the ends 96 and 138 are located at the same transverse and horizontal plane. By the way, always in this position shown on the figure 11b , the upper end 112 of this pusher 90 has penetrated into a through hole 113 of a plate 114 integrally mounted above the flap 30, the orifice 113 and the end 112 having a substantially identical diameter. This plate 114 has at its level lower surface a recess 116 for housing the end 150 fully extracted from the orifice 52.

It is therefore the abutment between these two elements 112, 113 which makes it possible to maintain the flap 30 in the position indicating position prohibiting the transport shown on FIG. figure 10 .

Referring now to the figure 11c showing the device 20 in a configuration in which the lateral and axial positioning of the assembly 4 in its housing 1 are both satisfactory, it can indeed be seen that this assembly has been sufficiently tightened by the locking system 6 so that is generated a plating of the side surface 14a of the assembly 4 against the side surface 16a of the housing 1, and a plating of the side surface 14b of the assembly 4 against the side surface 16b of the same housing 1 (the surfaces 14b and 16b not being visible on this figure 11c ).

During this tightening, the lateral movement of the assembly 4 in the housing 1, towards the surfaces 16a and 16b, has the effect of centering the orifice 98 of the nozzle 11 relative to the contact end 96 of shape truncated. Once this is done, the action of the compression spring 102 on the pusher 90 causes an automatic downward movement of the latter, authorized by penetration of the end 96 into the orifice 98, as is visible on the figure 11c . As such, it is noted that the orifice 98 could be replaced by any means likely to be penetrated by the end 96 of the pusher 90, such as a groove extending parallel to an edge of the tip 11. More generally, this means and the shape of the end 96 are selected in any way, the only condition being that they make it possible to control the lateral positioning of the assembly in a plane orthogonal to the axis 100 parallel to the direction 8, that is to say along two distinct directions orthogonal to this same direction 8.

In this position, it can be seen that the end 112 has been moved sufficiently downwards to be entirely extracted from the orifice 113. In fact, the upper end 112 is now housed in the end 150 of the pusher 124 , and thus arranged in the recess 116 of the plate 114. Thus, in this state, the pusher 90 no longer holds the flap 30 in abutment.

At the end of the clamping of the locking system 6, the two movable abutment members 124, 90 alone to control the contact of three orthogonal surfaces of the assembly 4 are normally positioned in the state shown on the figure 11c , in which they no longer hold the shutter 30 in abutment. From this moment, the free flap 30 is therefore only subjected to the action of the torsion spring 54 which causes the latter to pivot about the axis 60, during which the groove 156 therefore slides in the circular groove 58, as shown by the final position of the figure 12 .

On this figure 12 showing the control device 20 being in a configuration in wherein the positioning of the assembly within its housing is such that transport is allowed, it can be seen that the flap 30 has been moved automatically under the effect of the spring 54 is stopped in a precise angular position by a stop between the throat 156 (not visible on this figure 12 ) and one end of the through groove 58 opposite that opening into the orifice 52.

In this position indicating position allowing transport, the angular position of the flap 30 relative to the plate 22 is such that it covers the first zone 34 of the marking while opening another zone 119, the latter being also practiced on the upper surface of this plate 22 and made so as to indicate clearly and accurately to the operator that the assembly 4 is correctly positioned in the housing 1. This zone 119 is preferably of course a color different from that of the first zone 34.

Of course, various modifications can be made by those skilled in the art to the clamping system and the control devices which have just been described, by way of non-limiting examples only.

In particular, if the two preferred embodiments have been described with reference to a nuclear fuel assembly, it is to be understood that the invention is equally applicable to any assembly containing nuclear fuel intended to be placed in a housing. a storage basket, such as for example a box of pencils, and preferably having a polygonal section, such as a square.

In addition, it is noted that the control device can not only be integrated with a locking system intended to equip a given housing of the storage basket, but could alternatively be mounted directly on the latter.

Finally, it is noted that if the two preferred embodiments presented above are designed in such a way that they make it possible to indicate to an operator that the assembly is either in a positioning prohibiting the transport (after the loading the assembly, and translating unsatisfactory contact (s)), either in a position allowing transport (after tightening the locking device, and translating satisfactory contacts), or possibly in a position allowing its unloading (after the transport and loosening of the locking system, and reflecting the deposit of the assembly in the bottom of the housing), the invention also applies to devices designed to only indicate a positioning prohibiting unloading and a positioning allowing the unloading the assembly. In the latter case, the design device similar to one of those presented above is made so that the passage of the entire positioning prohibiting the unloading to the positioning allowing the unloading is identical to the passage previously described of the positioning authorizing transportation the positioning authorizing unloading, since in both cases, the assembly passes from a state in which it is distant from the bottom of the housing to a state in which it is in contact with the same bottom or very close to it .

Claims (15)

1. Monitoring device (20) of the position of an assembly containing nuclear fuel (4) in a housing (1) of a storage basket (2), characterised in that it comprises at least one mobile stop device (24, 26, 28, 124, 90) and a position indicator (30) suitable for being held at a stop by the mobile stop device in a first position indicating that the assembly occupies a first position in its housing, said mobile stop device (24, 26, 28, 124, 90) being arranged so as to be able to be placed, by means of contact with the assembly located in a second position in its housing, in a position enabling it to release the position indicator (30) devised to move automatically from the first position to a second position indicating that the assembly occupies said second position.
2. Monitoring device (20) according to claim 1, characterised in that it is devised such that said first position of the assembly corresponds to a position prohibiting transport and such that said first position of the indicator corresponds to a position indication position prohibiting transport, and in that it is also devised such that said second position of the assembly corresponds to a position enabling transport and such that said second position of the indicator corresponds to a position indication position enabling transport.
3. Monitoring device (20) according to claim 2, characterised in that the position indicator is also suitable for being held at a stop by at least one mobile stop device (24) in said position indication position enabling transport, said mobile stop device (24) being arranged so as to be able to be placed, by means of contact with the assembly located in a position enabling the unloading thereof from the housing, in a position enabling it to release the indicator (30) devised to move automatically from said position indication position enabling transport, to a position indication position enabling unloading of the assembly.
4. Monitoring device (20) according to claim 1, characterised in that it is devised such that said first position of the assembly corresponds to a position prohibiting the unloading of the assembly and such that said first position of the indicator (30) corresponds to a position indication position prohibiting the unloading of the assembly, and in that it is also devised such that said second position of the assembly corresponds to a position enabling the unloading thereof from the housing and such that said second position of the indicator corresponds to a position indication position enabling the unloading or the assembly.
5. Monitoring device (20) according to any of the above clams, characterised in that it comprises a plurality of mobile stop devices (24, 26, 28, 124, 90), each suitable for holding the position indicator (30) at a stop in said first position.
6. Monitoring device (20) according to any of the above claims, characterised in that it comprises a first mobile stop device (24, 124) arranged to move in translation in a first direction (8).
7. Monitoring device (20) according to claim 6, characterised in that said first mobile stop device (24, 124) takes the form of a thruster equipped with a throat (56, 156) cooperating with a groove (58) created in said position indicator (30).
8. Monitoring device (20) according to claim 6 or claim 7, characterised in that it also comprises a second mobile stop device (26) and a third mobile stop device (28) respectively arranged to pivot around a second direction (62) and a third direction (79), the first, second and third direction being orthogonal with each other.
9. Monitoring device (20) according to claim 8, characterised in that said first, second and third mobile stop devices (24, 26, 28) are equipped with elastic return means (40, 68).
10. Monitoring device (20) according to claim 6, characterised in that it comprises a fourth mobile stop device (90) arranged to move in translation in said first direction (8), said fourth mobile stop device (90) having a contact end (96) of tapered shape, of a parallel axis (100) with said first direction (8).
11. Monitoring device (20) according to claim 10, characterised in that said fourth mobile stop device (90) is equipped with elastic return means (102).
12. Monitoring device (20) according to any of the above claims, characterised in that said position indicator (30) takes the form of a flap equipped with elastic return means (54) enabling its automatic movement from said first position to said second position.
13. Monitoring device (20) according to any of the above claims, characterised in that said position indicator (30) cooperates with marking (34, 84, 119) created on a support (22) of said indicator (30).
14. Use of a monitoring device (20) according to any of the above claims, for monitoring the position of nuclear fuel or fuel rod box assemblies in their respective housings of a storage basket.
15. Locking system (6) of an assembly containing nuclear fuel (4) in a housing (1) of a storage basket (2), said system providing axial and lateral support of the assembly (4) in its housing (1), and being equipped with a monitoring device (20) according to any of the above claims.

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