FR2670946A1 - RADIOACTIVE SOURCE STORAGE FACILITY. - Google Patents

Abstract

To ensure the storage, replacement and transport of radioactive sources (44) used in a containment enclosure (12), an installation is proposed comprising a mobile storage tank (14), a docking member (88) mounted on a wall (10) of the enclosure, first sections of cables (46) carrying the radioactive sources, and second sections of cables (104) capable of being connected to the first sections. The storage castle (14) comprises a rotating body (22) provided with at least two curved storage tubes (40) each capable of receiving a source (44) and the first section of cable (46) carrying the latter. This section is normally blocked by a locking finger (54) which automatically releases the first section of cable when the castle (14) is docked on the docking member. The corresponding storage tube (40) is then aligned with a guide tube (96) and the transfer of the source between the enclosure (12) and the castle can be performed.

Description

RADIOACTIVE SOURCE STORAGE FACILITY.

DESCRIPTION

  The invention relates to an installation allowing

  both to store one or more radioactive sources usually placed in a containment enclosure, outside this enclosure, when these sources

  are not used This installation also allows

  to ensure the replacement of used sources as well

than their transportation.

  In the current state of the art, the stock-

  ge and transport of radioactive sources to the outside

  The containment enclosures in which these sources are usually placed are carried out by means of storage and transport castles which have not been designed to receive these sources.

  that the protection of personnel vis-à-vis the

  sources emitted during their transfer between

  the containment and the castle poses problems

  my difficult to solve In addition, the replacement

  from a used source requires special handling

  very long since two different castles must

  can be used to evacuate the used source and to

bring the new source.

  Document FR-A-2 544 542 also discloses a mobile barrel enclosure by means of which contaminated parts placed inside a confinement enclosure can be replaced and transported from one place to another. This mobile enclosure solves the problems posed by conventional transport castles However, it is particularly complex and expensive, so that its use must be reserved for replacement

  particular parts and is not suitable for replacement

cementing of radioactive sources.

  The object of the invention is precisely an ins-

  radioactive sources storage facility whose original design enables it to carry out

  particularly simple and safe for operations

  the storage, replacement and transport of radioactive sources usually contained in

containment enclosures.

  In its broadest definition, such a storage facility for radioactive sources is characterized by the fact that it comprises:

  a storage or biological protection castle

  nant a rotary barrel in which are housed at least two curved storage tubes opening at one end of the rotary barrel;

  at least a first section of cable carrying a source

  this radioactive at a first end, this section of cable being able to be received with said source in one of the storage tubes, so that a second end of the section of cable is accessible at said end of the rotary barrel when the source is in the bottom of the storage tube; means for blocking the section of cable in the

  rotating barrel, associated with each of the storage tubes

kage.

  Thanks to the curved nature of the storage tubes

  kage which are housed in the rotating barrel of the chateau, the operators are protected from radiation emitted by the source or sources which can be housed at the bottom of each of the tubes The operators can therefore safely carry out various preliminary operations

  or following the transfer of a source between the

  and a watertight enclosure, which is not the case with classically designed castles, in which

  the source is received in a rectilinear housing.

  Furthermore, the rotating barrel of the chateau comprising several storage tubes makes it possible to replace one or more radioactive sources (three in the case presented) using a single chateau,

  which was not possible before.

  Advantageously, the installation according to the invention

tion also includes:

  a docking member mounted on a wall of a

  girdle capable of containing the source, and on which can be docked said end of the rotary barrel, so that each of the storage tubes can be aligned with a guide tube passing through the wall

  and the docking member, by rotating said barrel-

  let; a second section of cable capable of being received in the guide tube and a first end of which can be coupled to the second end of the first section

of cable.

  In a preferred embodiment of the invention,

  vention, said end of the rotary barrel has a cylindrical portion which projects beyond an end surface of the storage castle, adapted to come

  resting against an abutment surface of the actuating member

  costage, this cylindrical part then penetrating into

  a complementary cylindrical recess formed in the or-

docking gane.

  Preferably, the locking means comprise

  an element capable of cooperating with the docking member

  ge to release the first cable segment when said end of the rotary barrel is approached on

the docking member.

  This element may in particular be constituted by a locking finger received in a sliding manner in

  a bore formed in said end of the rotating barrel

  tif and cutting one of the storage tubes, a passage formed in the locking finger being aligned with this storage tube when one end of the locking finger is flush with the exterior surface of said end of the rotary barrel, and elastic means acting on the locking finger to move it to a position for blocking the first section of cable, in which said end of the locking finger

  rusting protrudes beyond said outer surface

better.

  Advantageously, the installation according to the invention

  tion also includes a rolling cart, carrying the

  storage castle, so that an axis of the organ-

  docking line is aligned with the axis of rotation of the

rotating barrel.

  The storage castle can then comprise means for indexing the rotary barrel in rotation, determining positions in which each of the

  storage tubes is aligned with the guide tube.

  We will now describe, by way of example not

  limiting, a preferred embodiment of the invention

  tion, with reference to the accompanying drawings, in which: Figure 1 is a side view, in partial longitudinal section, showing an installation

  storage of radioactive sources carried out in accordance

ment to the invention;

  Figure 2 is a cross-sectional view

  the according to line II-II of Figure I; and FIGS. 3 A and 3 B are schematic side views illustrating, in longitudinal section, two stages in the implementation of the installation of the

  Figure 1, when replacing a radioactive source.

  In FIG. 1, the reference 10 designates a wall of a confinement enclosure 12 in which

  can be used from radioactive sources.

  The installation according to the invention makes it possible to temporarily store one or more of these sources

  outside the confinement enclosure 12, in order, for example, to replace it.

  This installation mainly comprises a storage castle, generally designated by the reference 14 This transport castle 14, of generally cylindrical configuration, comprises a thick wall

  se 16, made of a material absorbing the radiations emitted by radioactive sources, such as lead, or / and compound This wall 16 defines, along the axis XX 'of the storage castle 14, a cylindrical recess

  drique 18 closed at one end and whose end

  opposite leads to a front face 20 of the wall 16.

  A cylindrical body or barrel 22 is rotatably mounted inside the recess 18 The rotary barrel 22 is supported in part by a first bearing 24, mounted in a part 26 removably fixed in the bottom of the '' recess 18, and

  in which an extension 28 of the body 22 is received.

  This support is also provided by a second bearing 30, mounted in a flange 32 fixed, for example by means of screws 34, on the front face 20 of the wall 16, so that a cylindrical part 33 of the body 22, making protruding beyond the front face 20, is

received in this bearing 30.

  The cylindrical body 22 comprises a metal wall 36 forming the outer envelope of this barrel as well as the cylindrical part 33 Inside this wall 36 is placed a filling material 38, such as lead and / or compound capable of absorbing radiation emitted by radioactive sources. At least two curved storage tubes 40 are mounted in the cylindrical body 22 The bottom of these storage tubes 40 is placed in the filling material 38, near the end of the cylindrical body 22 supported by the bearing 24, while the opposite end of each of the tubes 40 opens onto the front face 42 of the cylindrical part 33 The curvature of each of the tubes 40 is such that the bottom of these tubes is located at a very short distance from the axis XX ′, while the end of the tubes emerging

  on the front face 42 is located at a relative distance

important part of this axis.

  This curvature of the storage tubes 40 per-

  puts, when a radioactive source 44 is placed in

  the bottom of one of these tubes, to prevent

  direct emissions from this source, do not diffuse along the tube to exit through the open end of

this one.

  Each of the radioactive sources 44 is

  of a section of cable 46 whose length is such that the end of this section projects beyond the front face 42 when the radioactive source 44 is

p Laced in the bottom of the tube 40.

  On the front face 42 of the projecting part of the cylindrical body 22, each of the storage tubes carries an end piece 48 onto which a protection and safety sleeve 50 can be screwed in which L is located the projecting end of the section of cable 46. As illustrated more precisely in the figure

  2, the cable sections 46 carrying the radioactive sources

  tives 44 are normally immobilized inside the storage tubes 40 by designated locking means

  generally by Reference 52.

  These rental means 52 include, for

  each of the storage tubes 40, a locking finger

  ge 54 which is slidably received in a bore 56 passing radially The projecting part of the cylindrical body 22 and the axis of which intersects the axis of the corresponding tube 40 The locking finger 54 is crossed by a passage 58, of the same diameter that the tube 40, which can be placed in alignment with the latter or

  offset from this tube, depending on the position used

  swung by the locking finger inside

bore 56.

  A pin 60 is housed in the projecting part of the cylindrical body 22, so as to cut the axis of the bore 56 through an oblong recess 62 formed in the locking finger 54 The cooperation between the pin 60 and the oblong recess 62 limits the movement of the locking finger 54 in one

  and the other direction inside bore 56.

  A first end of the locking finger

  ge 54, located near the axis XX ', is supported on a helical compression spring 64 also

  housed in the bore 56 The opposite end of this res-

  sort 64 is supported on the end of a screw 66 received

  in a tapped end portion of the bore 56.

  The spring 64 thus normally maintains the locking finger 54 in a locking position, in which the end of the oblong recess 62 la

  closer to the spring 64 is in abutment against the pin

  60 In this position of the locking finger 54, the axes of the passage 58 and of the storage tube 40 are offset by a value substantially equal to the diameter of the passage and the tube Consequently, when a radioactive source 44 is present in the bottom of the tube 40, the cable segment 46 welded to this source is blocked in the tube 40 by the locking finger 54,

  under the action of spring 64, as illustrated in the fig-

re 2.

  Advantageously, so that the blocking of the section

  cable lesson 46 in translation is more efficient, a

  pin 68 passes through the locking finger 54 perpen-

  perpendicular to its axis, so as to cut the passage

  58 according to a sequence, on the side of the spring 64.

  In the locking position of the finger

  rusting 54 illustrated in FIG. 2, the end of this finger opposite the spring 64, of hemispherical shape,

  protrudes beyond the cylindrical outer surface

  than 70 of the projecting cylindrical part 33 of the barrel

  let 22 As we will see later, this characteristic

  ristic allows to push the locking finger 54 into an unlocked position, in which the passage 58 is aligned with the storage tube 40 which

  corresponds to it, by acting on the hemispherical end

  that protruding from that finger, so that it is flush with the

cylindrical outer surface 70.

  In addition, it is possible to adjust the

  calibration of spring 64, i.e. the force with which

  the cable section 46 is blocked by the locking finger 54, by screwing or unscrewing more or

minus screw 66.

  The bores 56 containing the worm fingers

  rusting 54 associated with each of the storage tubes are offset from one another according to

axis XX '.

  The storage castle 14 further comprises indexing means making it possible to identify, during the rotation of the cylindrical body 22, the angular positions of the latter for which each of the

  storage tubes 40 is in an angular position

  relative area determined relative to the wall 16 of the castle When the latter is mounted on a transport cart 72 (Figure 1) moving on wheels

  74 so that its axis XX 'is oriented horizontally-

  talement, this angular position is such that the axis of the storage tube 40 considered is placed in a vertical plane containing the axis XX 'and above this axis in the embodiment shown in the figures. In practice and as shown in more detail in FIG. 2, these indexing means comprise for example a ball 76 carried by a screw 78 radially passing through the flange 32 and applied by a spring

  80 against the cylindrical outer surface

  that of the part 33 of the cylindrical body 22 located inside the flange 32 Axial grooves 82, of circular arc section, formed on this outer surface receive the ball 76 when one of the storage tubes 40 is located in the angular position

defined above.

  Thus, when an operator controls the rota-

  tion of the cylindrical body 22 inside the wall 16, for example by means of a key (not shown) engaging in blind holes 84 formed on the cylindrical outer surface of the part 33 of the cylindrical body, it stops this rotation when it feels the click caused by the penetration of the ball 76 into the groove 82 corresponding to the storage tube 40 in which a radioactive source must

be introduced or extracted.

  The storage castle 14 finally comprises a protective cover 86, shown in dashed lines in FIG. 1, fixed removably on the front face of the wall 16, so as to completely cover the projecting part of the cylindrical body 22, the flange 32

and the sleeves 50.

  To allow a radioactive source 40 to be transferred between the storage castle 14 and the confinement enclosure 12 delimited by the partition, the latter is equipped with a docking member which is in the form of a flange 88, fixed to the outer surface of the wall 10 for example by means

  of screws 90, as illustrated in Figure 1 IT is important

  so much to note that the axis of this flange 88 is coincident with the axis XX 'of the castle 14 when the latter is

mounted on carriage 72.

  On its outer face, the flange 88 has

  a crown-shaped part which delimits the interior-

  a cylindrical recess 92 open towards the outside and complementary to the cylindrical part of the body

  22 of the castle which protrudes beyond the face of

end 94 of flange 32.

  A rectilinear guide tube 96 passes through the wall as well as the flange 88, so as to open into the bottom of the cylindrical recess 92, at a location situated above the axis XX ′, so that the axis

  of this guide tube is located in a vertical plane not

  sant by the axis XX 'and at a distance equal to the distance separating the ends of the storage tubes 40 from this axis XX' In this way, the guide tube 96 is

  automatically placed in alignment with the storage tube

  kage 40 identified by the indexing means equipping Le

storage castle 14.

  Blind holes 98 are also formed

  in the wall 10 and in the flange 88, so as to open out

  expensive in the recess 92, opposite each of the other storage tubes 40 of the castle 14, when one of these storage tubes is located in the extension of the guide tube 96 The dimensioning of these blind holes 98 makes it possible to house the protective sleeves 50 sealing

  the other storage tubes 40 when the cylindrical part

  body plate 22 which protrudes beyond the surface 94 is received in the cylindrical recess

complementary 92.

  It should be noted that, when this cylindrical part of the body 22 which projects beyond the surface 94 is received in the recess 92, the locking pins 1 1 54 are automatically erased by the cooperation of the hemispherical ends of these fingers with a bevelled part 100 formed at the entrance to

  the recess 92 The radioactive source (s) 44 pre-

  paths in the storage tubes 40 are therefore automatically released when the surface 94 comes to bear

  against the end face 102, forming a bu surface

tee, flange 88.

  The installation according to the invention finally comprises a second segment of cable 104, intended to be received in the guide tube 96 and one end of which is equipped with a coupling device 106 capable of being fixed on a complementary coupling device 108 mounted at the end of the cable section 46 carrying

  radioactive source 44 Coupling devices

  ment 106 and 108 may in particular be constituted by quick couplings with screws, bayonets, or by any

equivalent mechanism.

  An example of use of the storage installation according to the invention to replace a radioactive source normally located inside a confinement enclosure 12 will now be described with reference to Figures 3 in turn. A and 3 B. As illustrated in Figure 3 A, the castle of

  storage 14 is first brought to the tank

  riot 72 (figure 1), near the docking flange

  88 After removing the protective cover 86, an operation

  rator manually rotates the cylindrical body 22, so as to bring, with the aid of the indexing means described above, an empty storage tube 40 opposite the guide tube 96 It then lifts the protective sleeve 50 from this tube empty storage, then it lands the castle 14 on the docking flange 88 by moving the carriage 72 on the rails 74, so as to penetrate the cylindrical end 33 of the body 22

  in the recess 92 of the flange 88.

  In this position, illustrated in the figure

  3 B, an operator pushes back using handling means

  lation provided remotely inside the containment 12 a set consisting of the radioactive source 44 to be replaced, the cable section 46 welded to this source and the cable section 104 coupled to the section 46 using devices 106 and 108 under

  the effect of this surge, the radioactive source to be

  place the path in the guide tube 96, then in the storage tube 40 located in the extension of the guide tube, until the stop of the radioactive source 44

  in the bottom of the tube 40 (arrow F).

  It should be noted that the movement of the source and of the cable sections associated with the latter is not hampered by the locking means 52 In fact, the latter then occupy their unlocking position, since the locking fingers 54 were _ 0 pushed back when entering the cylindrical part 33

  of the body 22 inside the recess 92.

  The operator then moves the carriage 72 carrying the castle 14 slightly backwards, so as to release the projecting cylindrical part from the body 22 from

  _ 5 the recess 92 During this backward movement, the eff-

  strong thrust exerted on the cable section 104 from inside the cell 12 is maintained until

  that the locking fingers 54 come out of the recess

  ment 92 A blocking of the cable section 46 under the action of the spring 64 acting on the locking finger 54

  corresponding is then obtained automatically.

  Under these conditions, the connecting devices

  cord 106 and 108 become accessible and can

  be disconnected by the operator The protective sleeve

  tion 50 of the corresponding storage tube 40 is also-

early set up.

  The operator can then introduce a source

  new radioactive inside the containment

12.

  For this, i L again manually rotates the cylindrical body 22, so as to bring in the extension of the guide tube 96 another storage tube 40 containing a new radioactive source fixed to a section of cable 46 After removing the protective sleeve 50 of this storage tube, the operator couples the connection device 108 to the connection device 106 with a section of cable introduced

  prealy in the guide tube 96.

  Landing of the castle 14 on the flange 88 is then carried out, which has the effect of releasing the section of cable Le 46 By acting from inside the confinement enclosure 12, The operator can thus transfer the radioactive source new inside

of this enclosure.

  To complete the operation, the operator backs up again the carriage 72 carrying the storage castle 14, then restores the protective sleeve 50 of the corresponding storage tube 40 as well as the protective cover 86 The used source can then be

  transported to another site, using the castle 14.

  It should be noted that during these various operations, the protection of personnel from

  radiation emitted by radioactive sources is

  Lisée, on the side of the castle 14, by the curved character

storage tubes 40.

  Of course, the invention is not limited to the embodiment which has just been described, but

  covers all the variants So we understand easily-

  ment that the number of storage tubes 40 provided in the cylindrical body 22 can be any number

  greater than or equal to two, within the limit of L'encombrée-

  ment that one wishes to give to the storage castle Furthermore, the locking means 52 could be constituted in a different way, the sliding locking fingers Lage being able in particular to be replaced by pivoting elements In addition, the search for 'a particularly simple and inexpensive solution has led to the design of a storage castle in which the rotation of the cylindrical body is controlled manually L Lement, but it is easily understood that this rotation can also be controlled by a motor Finally, L' horizontal orientation of the axis common to the castle

  and by means of docking provided on the wall of the enclosure-

  containment is not imperative, insofar as the castle can be placed on a system ensuring

  in a simple way its alignment with the device for

costage.

Claims (6)

  1 Radio source storage facility   active, characterized in that e L Le comprises: a storage castle (14) containing a rotary barrel (22) in which are housed at least two curved storage tubes (40) opening at one end of the rotary barrel; at least a first section of cable (46) carrying a radioactive source (44) at a first end, this section of cable being able to be received with said source in one of the storage tubes, so that a second end of the cable section is accessible at said end of the rotary barrel when the source is in the bottom of the storage tube; blocking means (52) of the cable section, in the rotary barrel, associated with each of the storage tubes.   2 Installation according to claim 1, ca-   characterized by the fact that it further comprises: a docking member (88) mounted on a wall (10) of an enclosure (12) capable of containing the source, and on which said end of the barrel can be docked   rotating, so that each of the storage tubes   kage (40) can be aligned with a guide tube (96) passing through the wall and the docking member, by rotation of said barrel; a second section of cable (104) capable of being received in the guide tube and a first end of which can be coupled to the second end of the first cable section.   3 Installation according to claim 2, ca-   characterized by the fact that said end of the rotary barrel (22) comprises a cylindrical part (33) which projects beyond an end surface (94) of the storage castle (14), capable of coming to bear against an abutment surface (102) of the docking member,   this cylindrical part then entering a hollow   complementary cylindrical ment (92) formed in the docking member. 4 Installation according to any of   Claims 2 and 3, characterized in that the   blocking means (52) comprise an element (54) able to cooperate with the docking member (88) to release   the first section of cable (46) when said end   tee of the rotary barrel is docked on the docking member.   Installation according to claims 3   and 4 combined, characterized in that said element   ment is a locking finger (54) received so   sliding in a bore (56) formed in said ex-   end of the rotary barrel (22) and cutting off one of the storage tubes (40), a passage (58) formed in the locking finger being aligned with this storage tube when one end of the locking finger is flush with the exterior surface from said end of the rotary barrel, and elastic means (64) acting on the locking finger (54) to move it to a position for blocking the first section of cable, in which said end of the locking finger   protrudes beyond said outer surface.   6 Installation according to any of   Claims 2 to 5, characterized in that it   includes a carriage (72) carrying the storage castle and rolling on rails t 74), so that an axis   of the docking member is aligned with the axis of rotation tion of the rotating barrel (22).   7 Installation according to claim 6, ca-   characterized by the fact that the storage castle (14) comprises indexing means (52) in rotation of the rotary barrel (22), determining positions in which one of the storage tubes (40) is aligned with the tube guide (96). 8 Installation according to any of   previous claims, characterized in that it comprises at least two sealing sleeves   removable (50) capable of being fixed on said end of the rotary barrel, in the extension of each of the storage tubes (40), so as to be able to enclose10 the second end of the first segment of cable (46) received in this storage tube .   9 Installation according to claim 8, combined with any one of claims 2 to   7, characterized in that the docking member (88) comprises at least one blind hole (98) capable of receiving a closure sleeve (50) when the end   of the rotary barrel is docked on the docking member with a storage tube, 40), without sleeve, placed in alignment with the guide tube (96) .20 10 Installation according to any one of the preceding claims, characterized by the fact   that it further comprises a removable protective cover (86) capable of being fixed on the transport castle (14), around the end of the rotary barrel (22). T