Classifications

• • G—PHYSICS
  • G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
  • G21F—PROTECTION AGAINST X-RADIATION, GAMMA RADIATION, CORPUSCULAR RADIATION OR PARTICLE BOMBARDMENT; TREATING RADIOACTIVELY CONTAMINATED MATERIAL; DECONTAMINATION ARRANGEMENTS THEREFOR
  • G21F5/00—Transportable or portable shielded containers
  • G21F5/06—Details of, or accessories to, the containers
  • G21F5/12—Closures for containers; Sealing arrangements
• • G—PHYSICS
  • G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
  • G21F—PROTECTION AGAINST X-RADIATION, GAMMA RADIATION, CORPUSCULAR RADIATION OR PARTICLE BOMBARDMENT; TREATING RADIOACTIVELY CONTAMINATED MATERIAL; DECONTAMINATION ARRANGEMENTS THEREFOR
  • G21F5/00—Transportable or portable shielded containers
  • G21F5/005—Containers for solid radioactive wastes, e.g. for ultimate disposal
  • G21F5/008—Containers for fuel elements
  • G21F5/012—Fuel element racks in the containers

Definitions

• the invention relates to a method for blocking a nuclear fuel assembly in a housing designed to receive this assembly.
• the invention also relates to a device designed to implement this blocking method.
• fuel assembly designates a nuclear fuel assembly.
• such an assembly comprises a rigid frame which supports a bundle of tubes, each tube containing a stack of nuclear fuel pellets and being closed at its ends.
• the invention applies in particular to the transport of fresh fuel assemblies, that is to say not irradiated. It can be used for all types of fuel assemblies, and in particular for those intended for pressurized water and boiling water nuclear reactors.
• Each transport package includes a cavity in which is housed a basket provided with one or more housings.
• the shapes and dimensions of the housings are such that each of them can receive a single nuclear fuel assembly.
• the number of housings provided in the same basket depends on the size of the fuel assemblies that one wishes to transport.
• Document FR-A-2 773 415 proposes to block a fuel assembly of square section inside its housing by placing, on two of the adjacent faces of the latter, adjustable clamping means which apply the assembly against the two other sides of the housing.
• the adjustable clamping means are operated from the open end of the housing. They can be fully mechanical or incorporate gas cylinders.
• the locking devices described in this document fulfill their function satisfactorily. However, they have the significant disadvantages of having a mass and a high manufacturing price, as well as a large size. In fact, the blocking devices are integrated into the walls of the cells, which significantly increases the thickness. The number of cells contained in the same package is therefore reduced by the presence of these devices. Consequently, the transport capacity of the packages is limited, which leads to increasing the number of transport operations to be carried out for recharging the core of a nuclear reactor. The overall price of delivery is increased.
• documents FR-A-2 674 667, FR-A-2 674 668 and FR-A-2 774 800 propose to clamp an assembly in its housing by making two adjacent sides of the housing on an articulated part of the packaging and placing clamping means on this articulated part.
• the invention particularly relates to a device designed to block a fuel assembly inside a housing by simple means, inexpensive and having a minimum size in the direction of 1, 'thickness of the walls of the housing, such so that more assemblies can be transported simultaneously.
• this result is obtained by means of a device for blocking a fuel assembly in a housing, the assembly comprising an upper end piece, and the housing comprising a first open end and a second end, the device being characterized in that it comprises means capable of producing a rigid connection between the upper end piece of the fuel assembly and the open end of the housing, in a predetermined relative position such that
• the assembly bears against at least one face of the housing over at least part of its length, said means capable of producing a rigid connection
• the blocking of the fuel assembly is effected by a device which connects the upper end of the assembly to the open end of the housing, this device can be placed in the housing, above the assembly . Consequently, the thickness of the walls which separate the adjacent housings can be given a minimum value. For a given size of the packaging, it is therefore possible to transport a larger number of assemblies than with the locking devices of the prior art. In addition, the mass and the manufacturing cost of the device according to the invention are reduced compared to the prior art.
• the fuel assembly and housing usually have polygonal sections, the more often square.
• the predetermined relative position between the upper end piece of the fuel assembly and the open end of the housing is then such that the upper end piece bears against two adjacent faces of the housing.
• the device further comprises a part of reduced section of the housing, located near the bottom thereof, said part of reduced section having substantially equal dimensions. to those of a lower nozzle of the fuel assembly.
• the predetermined relative position defined by the means capable of producing a rigid connection is such that the fuel assembly is not in contact with a shim placed in the second end of the housing.
• the means capable of producing a rigid connection comprise a connecting member capable of being fixed on the upper end of the assembly by first clamping means and capable of being fixed in the open end of the housing by second clamping means.
• the connecting member advantageously incorporates transverse displacement means, capable of moving the upper end piece of the assembly towards and away from the two adjacent faces of the housing, as well as means of axial displacement , able to move the assembly away from the second end of the housing and towards said second end.
• transverse displacement means capable of moving the upper end piece of the assembly towards and away from the two adjacent faces of the housing
• means of axial displacement able to move the assembly away from the second end of the housing and towards said second end.
• the first clamping means, the second clamping means, the transverse displacement means and the axial displacement means are actuated by separate control members, able to be operated separately.
• the connecting member has a longitudinal axis capable of being oriented parallel to a longitudinal axis of the fuel assembly.
• the first clamping means then preferably comprise jaws capable of moving over a first part of the connecting member in directions that are substantially radial with respect to said axis.
• the second clamping means comprise a bayonet ring capable of turning on a second part of the connecting member around said axis.
• the axial displacement means comprise means for controlling one. relative displacement between the first and the second part along said axis and the transverse - •• displacement means comprise at least one slide capable of moving on the first part of the connecting member in a direction substantially radial with respect to said axis. The slide then also forms part of the second clamping means.
• the first clamping means, the second clamping means and the axial displacement means are actuated by a single control member, and the transverse displacement means are actuated by another member.
• control able to be operated separately from one single control member.
• the single control member is advantageously a screw, anchored in a rotary manner on the connecting member, said screw acting on thrust rods forming both the first clamping means and the axial displacement means, and acting on jaws forming the second clamping means, by means of control rods articulated on the connecting member, on a nut engaged on the screw, on the thrust rods and on the jaws, and the means transverse displacement include thrust pads anchored on the connecting member.
• the first clamping means, the transverse displacement means and the axial displacement means are. actuated by a single control member.
• the second clamping means then comprise a separate fixing member.
• the single control member is advantageously a screw, anchored in a rotary manner on the connecting member, said screw acting on claws forming at the same time the first clamping means, the axial displacement means and the transverse displacement means, by means of a nut engaged on the screw and on which said claws are articulated.
• the invention also relates to a method of blocking a fuel assembly in a housing, the assembly comprising an upper nozzle, and the housing comprising a first open end and a second end, the method being characterized in that it is to make a connection rigid between the upper end of the fuel assembly and the open end of the housing above the upper end of the assembly, in a predetermined relative position such that the fuel assembly is not in contact with the bottom of the housing and is in abutment against at least one face of the housing over at least part of its length.
• FIG. 1 is a schematic vertical sectional view showing a fuel assembly maintained: "inside a housing of a basket of a transport packaging using a blocking device according to the invention
• - Figure 2 is a schematic top view of the assembly of Figure 1, held in its housing by the locking device 1 according to the invention;
• FIG. 3 is a vertical sectional view showing, in locked mode, a system for fixing the upper nozzle of a fuel assembly of a pressurized water nuclear reactor, according to a first embodiment of the invention
• - Figure 4 is a sectional view comparable to Figure 3, showing the fastening system when the fuel assembly is removed;
• - Figure 5 is a sectional view comparable to Figures 3 and 4, showing the fixing system when it is introduced into the upper end;
• FIG. 6 is a top view of the fastening system of Figure 3;
• FIG. 7 is a sectional view along the line VII-VII of Figure 6;
• - Figure 8 is a sectional view along line VIII-VIII of Figure 6;
• - Figure 9 is a vertical sectional view showing, in blocked mode, a system for fixing the upper nozzle of a fuel assembly of a boiling water nuclear reactor, according to a second embodiment of the invention;
• - Figure 10 is a vertical sectional view showing, in non-laterally tightened mode, the transverse displacement means which equip .the fixing system of Figure 9;
• Figure 11 is a top view of the fastening system of Figure 9;
• FIG. 12 is a vertical sectional view of a system for fixing the upper nozzle of a fuel assembly of a pressurized water nuclear reactor, illustrating a third embodiment of the invention
• - Figure 13 is a view comparable to Figure 12, showing the fastening system when engaging the claws of said system with the upper end of the assembly; and - Figure 14 is a view comparable to Figures 12 and 13, which shows the fixing system when locking the assembly in the high position and laterally offset.
• One or more housings L can be arranged in the same basket, without going beyond the ambit of the invention.
• Each housing L is dimensioned to receive a single assembly A.
• the interior dimensions of the housing L are slightly greater than those of assembly A.
• the assemblies A and the housings L generally have polygonal sections, most often square as illustrated schematically in FIG. 2.
• fuel assemblies A always include a rigid frame which supports a bundle of rods.
• Each pencil comprises a tube closed at its ends and in which is placed a stack of nuclear fuel pellets.
• the rigid frame comprises in particular an upper end piece ES, a lower end piece El and rods rigidly connecting these end pieces.
• the upper end piece ES can take different forms, depending on the type of reactor for which the assembly is intended.
• each housing L is delimited laterally by a tubular wall T whose section has a shape identical to that of the assembly A. This shape is square in FIG. 2. When the housing L is oriented vertically like the illustrates Figure 2, it is open at its upper end and fitted with a wedge C at its lower end.
• the bottom F of the cavity of the packaging in which the basket is placed blocks the lower end of the housing L.
• the wedge C is designed to axially support the assembly A at its lower end piece El.
• the open end of the housing L is materialized by a support plate, called "head plate" PT, fixed on the upper end of the tubular wall T.
• the packaging is generally oriented in such a way that 1 longitudinal axis of each housing L is substantially vertical.
• the transport takes place while the housings L are in the lying position, substantially horizontal.
• the assemblies A are then supported on two adjacent lateral faces of the housing L, turned downwards so as to form a V between them, as illustrated in FIG. 2.
• the device for locking the assembly A in its housing L mainly comprises a fixing system 10, designed to make a rigid connection between the upper end piece ES of the assembly A and the open end of the housing L, materialized by the PT head plate.
• this rigid connection defines a predetermined relative position between the assembly A and its housing L.
• the relative position thus defined is such that the fuel assembly A is not in contact with the shim C provided in the lower end of the housing L.
• This clearance allows the assembly to expand along its axis inside its housing without interfering with that -this.
• the value of this play can be around 6 mm.
• the fastening system 10 advantageously comprises axial displacement means able to move the assembly away from the bottom F of the housing L and towards said bottom.
• the fastening system 10 also comprises transverse displacement means, arranged so as to move the upper end piece ES of the assembly A towards the two adjacent lateral faces of the housing L intended to be turned downwards during transport of the packaging, and away from these two faces side.
• This movement is made possible by the fact that there is a predetermined play, in the transverse direction, between the assembly A and the housing L, over the major part of the height thereof. This play is necessary for the correct introduction of the assembly into its housing during loading.
• the value of this transverse play is approximately 6 mm.
• the blocking device further comprises a portion 12 of reduced section of the housing L, located near the bottom thereof. More specifically, this part 12 of reduced section is located at the level of the lower end piece El of assembly A and its dimensions are substantially equal to those of this end piece. Thus, the transverse displacement of the lower end piece El of the assembly A is greatly limited in the lower part of the housing - L.
• Part 12 of reduced section of the housing L is materialized by overhanging parts formed on the adjacent side faces of the housing L opposite the two adjacent side faces intended to be turned downwards during transport of the packaging.
• the two faces of the housing L intended to be turned downwards when the assembly is in a horizontal position have notches in their upper and lower parts, in line with the end caps ES and El. Consequently, taking into account the slight difference in cross-section between the end pieces and the current part of the assembly, the grids of the latter then come into contact with the two aforementioned faces of the housing, as shown in FIG. 1.
• This first embodiment of the invention relates to a fixing system 10 intended to be interposed between the upper nozzle ESI of a fuel assembly Al intended for a pressurized water nuclear reactor and a head plate PT1 materializing the end open housing Ll.
• the upper end piece ESI in this case comprises a solid lower plate PI, the square section of which defines the section of the assembly.
• the upper end piece ESI also includes an upper plate PS situated above and at a distance from the plate PI, when the assembly is oriented vertically.
• the upper plate - PS is hollowed out in its central part and rigidly connected to the PI plate by junction pieces not visible in the figures and located at the four corners of the ESI endpiece.
• the housing L1 is formed in this case inside a tube T of square section, the open upper end of which is fixed, for example by welding, in a hole TR of the same section, machined in the head plate PT1.
• the fastening system 10 comprises a connecting member 14 capable of being placed on the head plate PT1 so as to be centered on the hole TR made in it as well as on the recess of the plate upper PS of the upper end ESI of the assembly.
• the connecting member 14 comprises a flat bearing face 16 intended to be turned downwards when the assembly is oriented vertically.
• the connecting member 14 is fixed on the head plate PT1 and on the upper end piece ESI of the assembly Al, as illustrated in FIG. 3, the bearing face 16 is supported both on the upper face of the head plate and on the upper face of the nozzle.
• Two centering fingers 18 protrude downward from the bearing face 16.
• the centering fingers 18 penetrate into holes formed in the upper plate PS of the upper end piece ESI, so as to ensure centering of the 'connecting member 14 on this tip (see Figure 7).
• the connecting member 14 In its part located above the bearing face 16 the connecting member 14 supports, on its outer periphery, a ring 20 capable of freely rotating around a longitudinal axis 22 of said member 14, oriented parallel to the 'axis of the housing Ll when the connecting member 14 is fixed thereon.
• the crown 20 is provided externally with two lugs 24. These two lugs 24 are located in diametrically opposite locations.
• two flanges 26 are fixed, for example by means of screws, on the upper face of the head plate PT1, in diametrically opposite locations on either side of the hole TR, on one of the diagonals of the square formed in section by this hole.
• the pins 24 can either be engaged with the flanges 26, that is to say trapped between them and the upper face of the head plate PT1, or angularly offset with respect to said flanges 26.
• the connecting member is secured to the plate PT1 head. Otherwise, the connecting member is detached from the head plate.
• the arrangement thus produced forms a rigid connection of the "bayonet" type.
• the connecting member 14 also supports a first control member 27, mounted rotating about an axis parallel to the longitudinal axis 22.
• the first control member 27 is provided with an operating head 28. This makes it possible to control a rotation of the first control member 27 using a suitable tool.
• the first control member 27 is integral with a pinion 30. This pinion 30 is engaged on a toothed sector 32 provided for this purpose inside the crown 20.
• the arrangement which has just been described makes it possible to secure the connecting member 14 of the head plate PT or on the contrary to separate these two parts by controlling the rotation of the first control member 27 in one or the other sense using a suitable tool.
• the first control member 27, the crown 20 provided with its lugs 24 and the flanges 26 thus form means for making a rigid connection between the connecting member 14 and the open end of the housing L.
• the connecting member 14 supports a second control member 34, arranged along its longitudinal axis 22 and able to rotate around said axis.
• the second control member 34 is provided with an operating head 36. This makes it possible to control a rotation of the second control member 34 using a suitable tool.
• the second control member 34 has a thread 38.
• a cylindrical piece 40 is engaged on this thread 38 by a thread 42.
• the cylindrical piece 40 is secured to a disc 44 centered on the longitudinal axis 22.
• the disc 44 has teeth 46 • at its periphery. This toothing 46 is engaged on a pinion 48, integral with a third control member 50 carried by the connecting member 14.
• the third control member 50 is mounted on an axis parallel to the longitudinal axis 22 and able to rotate around said axis. At its accessible end on the upper face of the connecting member 14, the third control member 50 is provided with an operating head 52. This makes it possible to control a rotation of the third control member 50 using a suitable tool.
• the cylindrical piece 40 is integral with a pin 54 whose axis is offset by relative to the longitudinal axis 22.
• This pin 54 enters a cam groove 56 machined in a slider 58.
• the slider 58 is itself mounted so that it can slide in a tubular part 59.
• Said tubular part is supported by a tubular part 64 mounted on the cylindrical part 40, so that the tubular part 59 can slide along the longitudinal axis 22, while being immobilized in rotation around this axis.
• the tubular part 59 projects downwards inside the recess formed in the upper plate PS of the upper end piece ESI.
• the slide 58 is able to move relative to the tubular part 59 in a direction orthogonal to the longitudinal axis 22 and oriented diagonally relative to the square formed in section by the housing L1.
• bearing surfaces 60 formed on pads 62 integral with the slider 58 can come to bear against the adjacent faces of the housing L1 opposite to those which must be oriented downwards when the packaging is transported in a horizontal position.
• the arrangement which has just been described makes it possible, by acting on the third control member 50, to move the upper end piece ESI of the assembly transversely towards said faces intended to be oriented downward, by bearing on the faces opposed by the pads 62.
• the control member 50 thus constitutes, with the cylindrical part 40 and the slide 58, means for transversely moving the upper end piece ESI of the assembly.
• This assembly is also part of the second clamping means, by the fact that it makes it possible to clamp laterally the connecting member 14 in the open end of the housing L1.
• the cylindrical part 40 coaxially supports the tubular part 64. More specifically, the tubular part 64 is mounted on the cylindrical part 40, along the longitudinal axis 22, so as to be able to rotate freely around said cylindrical part 40 , while being linked to it in the direction of the longitudinal axis 22.
• the tubular part 64 is integral with a disc 66, also centered on the longitudinal axis 22.
• the disc 66 is provided with a toothing 68. This toothing 68 is engaged on a pinion 70, integral with a fourth control member 72 carried by the connecting member 14.
• the fourth control member 72 is mounted on an axis parallel to the longitudinal axis 22 and able to rotate around said axis. At its accessible end on the upper face of the connecting member 14, the fourth control member 72 is provided with an operating head 74. This makes it possible to control a rotation of the fourth control member 72 using a suitable tool.
• the tubular part 64 is integral with a plate carrying a spiral toothing 76 on its face turned downwards. Said face is situated in a plane perpendicular to the longitudinal axis 22.
• each of the jaws 78 are mounted in the tubular part 59, so that they can slide parallel to the faces of the housing L1, towards and away from said faces, in said tubular part.
• each of the jaws 78 On its upper face, each of the jaws 78 has a spiral toothing which engages on the spiral toothing 76 carried by the tubular piece 64.
• each of the jaws 78 supports swiveling manner a V (not illustrated) capable of coming to bear against the lower internal corner of one recess formed in the upper plate PS of the upper end piece ESI of the assembly.
• the second control member 34 thus constitutes, with the thread 38 and the internal thread 42, means for axial displacement of the assembly.
• the heights of the teeth 46 and 68 of the discs 44 and 66, which are axially movable with the parts 40 and 64, and that of the teeth of the pinions 48 and 70, which are axially fixed relative to the connecting member 14, are determined so that these teeth remain continuously engaged.
• the fastening system 10 is mounted on the upper nozzle ESI of the fuel assembly before the latter is introduced into its housing L1. To this end, the slide 58 and the jaws 78 are first retracted into the connecting member 14 and the parts 40 and 64 are placed in the high position relative to this connecting member. In addition, the crown 20 is placed in the "unlocked" position.
• the tubular part 59 and the connecting member 14 are introduced into the recess of the plate upper PS of the upper end piece ESI until the bearing face 16 comes into contact with the upper face of this end piece.
• the fourth control member 72 is then actuated, so as to bring the jaws 78 against the lower internal corners of the recess formed in the upper plate PS.
• the fastening system 10 is then rigidly secured to the upper end piece ESI of the assembly.
• the assembly is then suspended from the fixing system 10, which thus allows the assembly to be handled in a safe manner.
• the fastening system 10 to which the assembly is suspended is then brought above the housing L1 and gradually lowered.
• the lower end piece El is positioned in the transverse direction by the section part 12. reduced housing ( Figure 1).
• the bearing face 16 of the connecting member 14 comes to bear on the upper face of the head plate PT1
• the lower end piece El remains separated from - the wedge C and from the bottom F of the cavity .
• the operator then actuates the third control member 50, so as to bring the pads 62 to bear against the two faces of the housing L1 intended to be turned upwards during the subsequent transport of the packaging (FIG. 2).
• the upper end piece ESI is thus applied against the two other faces of the housing L1, intended to be turned downwards during transport. There is therefore made a transverse clamping of the upper end piece ESI in the housing L.
• the operator then actuates the first control member 27 (FIG. 6), so as to secure the fixing system 10 of the head plate PT1.
• the operator preferably applies a pre-established tightening torque, so as to perform a function of embedding the upper end piece ESI in the housing L. This therefore takes into account the accelerations likely to be encountered under normal conditions of transport.
• the operator When the transport is complete, the operator first activates the first control member 27, in order to separate the fixing system 10 from the head plate PT1.
• the operator actuates the fourth control member 72, in order to separate the fixing system 10 from the upper ESI nozzle.
• the fastening system 10 can then be removed, as illustrated in FIG. 4, and the assembly unloaded from the transport packaging using the tools usually used in nuclear power plants.
• This second embodiment of the invention relates to a fastening system 10 'intended to be interposed between the upper nozzle ES2 of a fuel assembly A2 intended for a nuclear water reactor boiling water and a PT2 head plate materializing the open end of an L2 housing.
• the upper end piece ES2 of the assembly A2 comprises in this case a solid plate P2, forming a square in top view, to which is fixed a handle AN forming an inverted U in view next to.
• the AN handle is located in a plane passing through a diagonal of the square and the longitudinal axis of the assembly.
• the housing L2 is delimited inside a tube T, the open upper end of which is welded into a hole TR machined in the head plate PT2.
• the fixing system 10 ′ comprises a connecting member 14 ′ capable of coming to be placed on the head plate PT2 so as to be centered on the hole TR made in it Ci as well as on the handle AN of the upper end piece ES2 of the assembly.
• the connecting member 14 ' is in the form of a square plate whose dimensions are substantially the same as those of the hole TR in which it is placed.
• a single control member, materialized by a screw 80, is anchored in the center of the connecting member 14 ', so as to project upwards when the fixing system 10' is placed on the housing L2 and when the latter this is oriented vertically. More specifically, the screw 80 is articulated on the connecting member 14 'by a ball joint 82. At its upper end, the screw 80 is provided with an operating head 81 allowing its actuation using a suitable tool.
• a nut 84 is engaged on the screw 80.
• the first ends of two rods 86 are articulated on the nut 84 by a common axis, orthogonal to that of the screw 80.
• the opposite ends of each of the rods 86 are articulated on the first ends of two control rods 88 by axes 90 parallel to the articulation axis of the rods 86 on the nut 84.
• Each of the control rods 88 is itself articulated on the connecting member 14 'by an axis 92 parallel to the axes 90. More specifically, the axes 92 are arranged symmetrically on either side of the ball joint 82.
• the second end of each of the control rods 88, located below the connecting member 14 ', is articulated at the end of a thrust rod 94 by an axis 96, parallel to the axes 90 and 92.
• the thrust rods 94 are supported by gravity on stop rods 98 integral with the connecting member 14 '. Their opposite ends can thus come to bear under the upper branch of the handle AN of the upper end piece ES2, as illustrated in particular in FIG. 7.
• the rods 86, the control rods 88 and the thrust rods 94 are arranged in a plane passing through the longitudinal axis 22 'of the connecting member 14' and by a diagonal of the square formed in top view by said member.
• the thrust rods 94 thus form, at the same time, means of axial clamping of the connecting member 14 'on the upper end piece ES2 of the assembly A2 and means of axial displacement of the latter parallel to the longitudinal axis 22 'of the connecting member 14'.
• the connecting member 14 supports two jaws 100 capable of sliding along the diagonal of the square that it forms in top view. More specifically, the jaws 100 are located at the two opposite points of the aforementioned square. Each of them comprises a projecting part 102, capable of being placed in a housing 104 provided for this purpose at the entrance to the hole TR formed in the head plate PT2.
• Two articulated rods 106 connect the jaws 100 to each of the control rods 88, at a location of these located between the axes 90 and 92.
• the jaws 100 thus constitute means for axial clamping of the connecting member 14 'on the head plate PT embodying the open end of the housing L2.
• a damping element (not shown) is advantageously interposed between each link 106 and the jaw 100 which corresponds to it.
• This damping element allows the jaws 100 to fulfill their clamping function whatever the precise position in which the thrust rods 94 bring the upper branch of the handle AN to bear against the underside of the connecting member 14 '.
• two rigid protective sheets 108 protrude downward, from two adjacent edges of the square plate forming the connecting member 14 '. More specifically, the protective sheets 108 are arranged along the sides intended to be turned upwards during the subsequent horizontal transport of the packaging. They extend down to between the plate massive P2 of the upper end piece ES2 and the housing L2, when the fixing system 10 'is fixed in the upper part of a housing L2 containing an assembly A2.
• Each of the protective sheets 108 carries, on its face intended to be turned towards the interior of the housing L2, a leaf spring 110 provided with a support element 112 at its lower end. A part of this support element 112 is received between the protective sheet 108 and the adjacent edge of the solid plate P2, when the fixing system 10 'is introduced into the upper part of a housing L2 containing an assembly A2. Thanks to the leaf spring 110, the support element 112 ensures the lateral displacement of the upper end of the assembly.
• the arrangement which has just been described allows an operator to move the upper end piece ES2 of the assembly A2 towards the two faces of the housing L2 intended to be oriented downwards during the subsequent transport of the assembly in its packaging. in horizontal position.
• a thrust shoe 114 in the form of a wedge, is interposed between each protective sheet 108 and the support element 112 which corresponds to it.
• Each thrust shoe 114 comprises a threaded hole in which is engaged a control screw 116. This is mounted on the connecting member 14 'so as to be able to rotate freely relative to the latter, while being linked said member parallel to its axis 22 '.
• Each of the two control screws 116 comprises an operating head
• the thrust pads 114 thus constitute means for transversely clamping the upper end piece ES2 of the assembly in its housing L2.
• the fastening system 10 is designed to be mounted at the top of the housing L2 while the assembly A2 has already been introduced therein. Consequently, the lower end of the assembly then rests on the wedge C and on the bottom F of the cavity of the packaging.
• the operator brings the fixing system 10 'above the assembly A2.
• the fastening system is then in its unlocked position, that is to say that the nut 84 is in the low position on the screw 80.
• the ends of the thrust rods 94 are distant from the underside of the plate forming the connecting member 14 'and spaced from each other by a distance greater than the width of the handle AN.
• the jaws 100 are retracted towards the center of the connecting member 14 '.
• the lower end of the protective sheets 108 enters the housing L2.
• the upper branch of the handle AN is automatically centered by a drain 99 located in the lower part of the connecting member 14 '.
• the support elements 112 mounted on the leaf springs 110 simultaneously provide prepositioning of the upper end piece ES2 against the corner of the housing intended to be turned downwards during the horizontal transport of the packaging.
• a precise centering of the fastening system 10 'on the housing is then ensured by the embedding of the connecting member 14' on a complementary machining formed at the entrance of the hole TR of the head plate PT2.
• the final positioning of the system is obtained when the connecting member 14 'comes to bear on the head plate PT2.
• This third embodiment of the invention relates to a 10 "fixing system intended to be interposed between the upper nozzle ES3 of a fuel assembly A3 intended for a nuclear pressurized water reactor and a head plate PT3 materializing the open end of a housing L3.
• the upper end piece ES3 of the assembly A3 comprises in this case a lower solid plate P3, forming a square in top view.
• the upper end piece ES3 also includes an upper plate PS situated above and at a distance from the solid plate P3, when the assembly is oriented vertically.
• the upper plate PS is hollowed out in its central part and rigidly connected to the plate P3 by connecting pieces PJ located at the four corners of the end piece.
• the housing L3 is formed as previously inside a tube T of square section, the open upper end of which is fixed, for example by welding, in a hole TR of the same section, machined in the head plate PT3.
• the fastening system 10 "comprises a connecting member 14" capable of being placed on the head plate PT3 so as to be centered on the hole TR made in the latter using guide pins not shown.
• Clamping means such as screws 119 are provided to ensure a rigid connection between the connecting member 14 "and the head plate PT3 when the screws are put in place.
• the connecting member 14 " is provided with balusters 121 which project downwards. For simplicity, only one of these balusters 121 is shown in FIG. 10. The lower faces of these balusters 121 form abutment surfaces. come to bear on the upper face of the upper plate PS of - the upper end piece ES3 of the assembly. -
• a single control member 120 is rotatably supported at the center of the connecting member 14 ", while being immobilized on said member parallel to its axis 22 ". At its upper end, the single control member 120 is provided with an operating head 122 enabling it to be actuated using a suitable tool.
• the single control member 120 In its lower part, located below the connecting member 14 ", the single control member 120 comprises a thread 124 on which is engaged a nut 126. Said nut 126 is immobilized in rotation relative to the member link 14 ", so that a rotation of the single control member 120 has the effect of controlling a displacement of the nut 126 upwards or downwards, parallel to the axis 22 ".
• each of the claws 128 is articulated on one nut 126 by their upper ends. This articulation is provided by pivot axes 130 oriented in directions orthogonal to the axis 22 "of the connecting member 14". More precisely, the pivot axes of the claws 128 are all arranged in the same plane perpendicular to the axis 22 ", at equal distance therefrom. In addition, the pivot axes 130 of the claws 128 arranged on either side other of the longitudinal axis 22 "are parallel to each other and orthogonal to the pivot axes 130 of the other two claws 128. At its lower end, each of the claws 128 comprises a bent portion 140, which projects substantially at right angles to the outside.
• two adjacent claws 128 are equipped with support rollers 142. More specifically, these rollers 142 equip the claws 128 intended to come into contact against the internal faces of the parts of the recessed upper plate PS which will be applied against the faces of the L3 housing intended to be turned downwards during the subsequent transport of the packaging in a horizontal position.
• each of the claws 128 further comprises, on its side facing the longitudinal axis 22 ", a lug 132 placed above a stop rod 134 secured to the connecting member 14".
• a torsion spring 136 is wound around each of the pivot axes 130 and is supported both on a rod 138 integral with the nut 126 and on the corresponding claw 128, so as to apply a lateral force on the end piece.
• the lugs 132 of the claws 128 not equipped with rollers 142 are terminated by a stop 133 provided to come into abutment against a surface 127 of the nut 126, when the bent portions 140 of the claws 128 are placed under the plate upper PS of the upper end piece ES3.
• the lateral displacement of the upper end piece ES3 towards the two required faces of the housing L can thus be ensured by the two claws 128 provided with rollers 142, under the action of the lateral forces exerted on said end piece by the springs 136.
• the single control member 120 makes it possible to control the pivoting of the claws 128 which form both means for clamping the connecting member 14 "on the upper end piece ES3 of the assembly and means for axial displacement of the assembly along the longitudinal axis 22 ".
• the springs 136 form means for transversely moving the upper end piece ES3 towards the corner of the housing L3 intended to be turned downwards during the transport of the packaging to the horizontal.
• an actuation of the single control member 120 has the effect of spreading the claws 128, of moving them up along the axis 22 "and of position the bent parts 140 under the upper plate PS.
• the two rollers 142 first come into contact with the corresponding inner faces of the obviously of the upper plate PS of the upper end piece ES3.
• a transverse displacement of this end piece towards the aforementioned lower corner of the housing L3 is then obtained by means of the springs 136.
• the bent portions 140 of the claws 128 then come to bear under the upper plate PS, which has the effect of lifting the assembly in his accommodation.
• the upper plate PS is brought to bear against the lower faces of the columns 121 carried by the connecting member 14 ", which has the effect of securing this member of the upper end piece ES3 of the assembly.
• the fixing system 10 is intended to be mounted in the top of the housing - L3 while the assembly A3 has already been introduced therein. lower end of the assembly then rests on the wedge C and on the bottom F of the packaging.
• the operator brings the fixing system 10 "above the assembly A3.
• the fixing system is then in its retracted or unlocked position, that is to say that the nut 126 is in the low position by relative to the single control member 120.
• the bent parts 140 are retracted towards the axis 22 "and away from the underside of the recess formed in the upper plate PS.
• the fixing system 10 is introduced into the upper part of the housing L3 as illustrated in FIG. 12 and centered on the head plate PT3 using pins (not shown).
• the connecting member 14" is then secured to the PT3 head plate, for example by means of screws 119.
• the rollers 142 come into contact with the two corresponding faces of the recess formed in the upper plate PS, which has the effect of applying the upper end piece ES3 against the aforementioned lower angle of the housing L3 ( Figure 13).
• this housing may in particular belong to a device for transporting assemblies, to a storage basket in a swimming pool or to a storage area for combustible assemblies, provided in any installation.

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• Physics & Mathematics (AREA)
• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• High Energy & Nuclear Physics (AREA)
• Packaging Of Machine Parts And Wound Products (AREA)
• Automatic Assembly (AREA)

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• 2002
  • 2002-12-19 AU AU2002365009A patent/AU2002365009A1/en not_active Abandoned
  • 2002-12-19 WO PCT/FR2002/004459 patent/WO2004066313A1/fr active Application Filing
  • 2002-12-19 EP EP02808356A patent/EP1573750B1/de not_active Expired - Lifetime
  • 2002-12-19 US US10/539,282 patent/US20080049886A1/en not_active Abandoned
  • 2002-12-19 JP JP2004566964A patent/JP4291277B2/ja not_active Expired - Lifetime
  • 2002-12-19 DE DE60231922T patent/DE60231922D1/de not_active Expired - Lifetime

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