JP2713321B2 - Equipment for storing radioactive sources - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to one or more radioactive sources (or radioactive sources) which are normally located within a enclosure (or enclosure) when not in use and which are located outside the enclosure when not in use. Source / radioactiv
equipment (installatio) that can store
n). The equipment also allows the replacement of used radioactive sources and their transport.

[0002]

2. Description of the Prior Art In the current state of the art, a radioactive source is transported out of an enclosure in which it is usually arranged,
Storage is carried out using transport and storage casks or flasks. However, these casks are not designed to receive the radioactive source. Therefore, when transporting those radioactive sources between the enclosure and the cask, there are difficult problems that must be solved in order to protect the carriers from the radiation emitted by the radioactive sources. Furthermore, replacing long-lived radioactive sources requires particularly long maneuvers. This is because two different casks must be used in order to remove the spent radioactive source and insert a new one.

[0003] FR-A-2 544 542 describes a movable tubular closure which can be moved from one place to another in order to replace contaminated parts in the closure. Has been disclosed.
This movable enclosure solves the problems encountered with conventional transport casks. However, this movable cask is very complex and expensive. Therefore, the special part (special
Its use must be withheld to replace parts, and this movable cask is not suitable for replacing radioactive sources.

[0004]

OBJECTS OF THE INVENTION The object of the present invention is to provide a facility for storing radioactive sources, in particular due to its original construction, the storage, replacement and transport of radioactive sources usually housed in enclosures. It is an object of the present invention to provide a facility that enables a worker to perform work in a very simple and low-risk manner.

[0005]

Means for Solving the Problems In the broadest definition,
The radioactive source storage facility described above is characterized by comprising the following. That is, one is a biological protection or storage cask including a rotating drum, which contains at least two inwardly curved storage tubes that appear at one end of the drum. One more thing,
At least one first cable section carrying a radioactive source at a first end of the cable section, said first cable section being capable of accommodating said radioactive source in one of the storage tubes; the second end portion, when the radioactive source is in the bottom of the storage tube, from said one end of the rotary drum
It is configured to protrude . Still another is means for locking the cable section in the rotating drum in relation to each of the storage tubes.

The nature of the inwardly bent storage tubes housed in the rotating drum of the cask protects workers from radiation from radioactive sources located at the bottom of each of the tubes. Thus, the worker can safely perform many tasks before and after transferring the radioactive source between the cask and the enclosure. The above is not an example using a cask having a conventional configuration. In the conventional cask, the radioactive source is housed in a linear cavity.

In addition, the rotating drum of the cask has several storage tubes, one or more of which (in the case of the embodiment,
(3 ) radioactive sources can be replaced using a single cask, which has been a task not possible in the past.

Advantageously, the installation according to the invention also comprises an engaging member mounted on one wall of the enclosure capable of containing the radioactive source and engaging with said one end of the rotating drum. The rotation of the drum causes each of the storage tubes to be aligned with the guide tube and the engagement member across the wall. The facility also comprises a second cable section housed in the guide tube, the first end of which is connected to the second end of the first cable section.

In a preferred embodiment of the present invention, one end of the rotating drum has a cylindrical portion protruding from the end surface of the storage cask, and the cylindrical portion contacts the engaging member contact surface and is formed on the engaging member. Penetrates a complementary cylindrical cavity.

[0010] Preferably, the stop means comprises an element cooperating with the engaging member to release the first cable portion when the rotating drum is engaged with the engaging member. The element is formed at one end of the rotary drum in addition to elastic means acting on the stop pin to move the stop pin toward the stop position of the first cable portion where the end of the stop pin projects from the end face of the drum. It is particularly constituted by a locking pin slidably received in the bore provided and intersecting one of the storage tubes.
The passage formed in the stop pin is aligned with the storage tube when one end of the stop pin contacts the outer surface of one end of the rotating drum at the same level.

Advantageously, the installation according to the invention also comprises a trolley or a carriage, which carries the storage cask so that the axis of the engagement member is aligned with the axis of rotation of the rotating drum.

[0012] The storage cask also comprises rotating drum rotary indexing means for determining the position at which each of the storage tubes is aligned with the guide tube.

[0013]

BRIEF DESCRIPTION OF THE DRAWINGS A detailed description of a preferred embodiment of the present invention is provided below with reference to the accompanying drawings.

In FIG. 1, reference numeral 10 denotes a sealing body 12.
Shows one of the walls. The radioactive source is
Used in The facility of the present invention allows one or more radioactive sources to be temporarily stored outside of enclosure 12 to replace the radioactive sources.

[0015] The facility of the present invention mainly comprises storage casks or flasks in general terms.
k) consists of 14. The generally cylindrical transport and storage cask 14 comprises a thick wall 16 formed of a material that absorbs radiation emitted from a radioactive source, for example, lead or a compound thereof. Along the axis XX ′ of the storage cask 14,
6 is one end closed and the other end is the front surface 2 of the thick wall 16.
Cylindrical recess appearing at zero
18 are defined and limited.

The cylindrical rotating drum 22 is mounted in the cavity 18 so as to be rotatable. This cylindrical rotating dora
The part 22 is partially supported by the first bearing 24 and placed on the part 26, and a cylinder is provided inside the part 26.
The extension 28 of the rotating drum 22 is supported,
The cylindrical rotary drum 22 is detachably fixed to the bottom of the cavity 18 (that is, the bottom on one end side where the cavity is closed). Support function is also fulfilled by a second bearing 30, the front face 20 of the thick wall 16 by the bearing, for example a screw 34
The cylindrical portion 33 of the cylindrical rotary drum 22, which is mounted on a flange 32 fixed to the front surface 20 and protrudes from the front surface 20, is supported by the bearing 30.

The cylindrical rotary drum 22 comprises a metal wall 36 forming an outer layer of the body, and the cylindrical portion 33 is also made of the same metal. The inside of the metal wall 36 is filled with a filler 38 made of lead or a lead compound capable of absorbing radiation emitted by the radioactive source.

At least two inwardly curved storage tubes 40 are mounted on the cylindrical rotating drum 22. The bottoms of these storage tubes 40 (ends on the extension 28 side) are disposed inside the packing 38 near the end of the cylindrical rotary drum 22 supported by the bearing 24. The opposite end of each storage tube, on the other hand, appears at the front face 42 of the cylindrical portion 33. The bending of each storage tube 40 depends on these storage tubes.
The bottom of 40 is set so as to be very close to axis XX ', while the end of storage tube 40 , which emerges from front surface 42, is set to be relatively far from axis XX'.

When the radioactive source 44 is located at the bottom of one of the storage tubes 40 , the storage tubes 40 are curved as described above.
ure) directly the radiation emitted by a radioactive source for which is not diverge along the storage tube 40, not Ika exits through an opening in the end of the storage tube 40.

Each of the radioactive sources 44 and the cable section 4
6, when the radioactive source 44 is located at the bottom of the storage tube 40, the cable section is long enough for the end of the cable section to protrude from the front face 42.

On the front side 42 of the projecting portion 33 of the cylindrical rotary drum 22, each storage tube 40 holds an end face mounting bracket 48, which is protected by a protective safety sleeve.
An on andsafety sleeve is screwed in and houses the end of the protruding portion of the cable portion 46.

As shown in detail in FIG.
The cable section 46 carrying the 4 is normally fixed in the storage tube 40 by a stop means 52.

For each storage tube 40, the stop means 52 is circular.
A locking pin slidably supported by a bore 56 running radially through the projecting portion 33 of the column rotating drum 22.
The axis of this pin 54 intersects the axis of the corresponding storage tube 40. Locking pin 5
4 is a passage having the same diameter as the storage tube 40
58 we are crossing through. And this passage 58 is a hole
Relative to the position dominated by the locking pin in 56
And can be aligned with the storage tube 40, and
The position for the storage tube 40 can be interchanged.

An oblong cavity (ob) formed in the retaining pin 54
A pin 60 is provided at the protruding portion of the cylindrical rotary drum 22 so as to intersect with the axis of the hole 56 passing through the long recess 62. By cooperating the pins 60 and the elongated cavities 62, the displacement of the locking pins 54 is limited in either direction within the hole 56.

The first of the stop pins 54 near the axis XX '
Is in contact with a helical compression spring 64 further located in bore 56. The opposite end of the compression spring 64 is tapped end portio of the hole 56.
It is in contact with one end of the screw 66 supported in n).

Accordingly, the spring 64 typically places the stop pin 54 in a stop position, where the end of the elongated cavity 62 closest to the spring 64 is in contact with the pin 60. In this position of the stop pin 54, the axis of the passage 58 and the storage tube 40 has been shifted by a value approximately equal to the diameter of the passage 58 and the storage tube 40. Thus, when the radioactive source 44 is at the bottom of the tube 40, the cable portion 46 associated with the radioactive source is stopped by the locking pin 54 in the storage tube 40 following the operation of the spring 64 as shown in FIG.

Advantageously, the transport of the cable section 46
To ensure that the stop inside is more effective ,
The side close to the spring 64, to so that transect the passage 58 by the dividing line (secant), the pin 68 is Ru Ttei transected stop pin 54 perpendicular to its axis. Thereby, the cable part 4
6 is stopped between the pin 68 and the opposite side of the hole 56.
You. In this way, the contact surface is reduced and the stop pressure is increased.
Will be great.

In the stop position of the stop pin 54 shown in FIG. 2, the end of the stop pin 54 on the opposite side of the spring 64 is hemispherical, and has a cylindrical shape outside the projecting cylindrical portion 33 of the cylindrical rotating drum 22. It protrudes from the surface 70. As will be described below, this feature allows the locking pin 54 to be pushed back to an unblocked position. By acting on the hemispherical protruding end of the pin 54, the passage 58 is aligned with the corresponding storage tube 40 in the unlocked position and the pin is flush with the outer cylindrical surface 70. .

The scale of the spring 64, ie, the elastic force by which the cable portion 46 is stopped by the locking pin 54,
Can be adjusted by tightening or loosening the screw 66 more or less. Holes 56 containing stop pins associated with each storage tube 40 are shifted back and forth with respect to axis XX '.

The storage cask 14 is also provided with indexing means (in
dexing means), and while the cylindrical rotary drum 22 is rotating, the indexing means allows the cylindrical rotary drum 22 to rotate.
Can be accurately indicated. Each storage tube 40
Is located at a relative angular position determined with respect to the cask wall 16. Car 74
When the body of the cylindrical rotating drum 22 is mounted so that the axis XX ′ is oriented parallel to the transport trolley 72 (FIG. 1), the angular position of the cylindrical body is determined by the axis of the storage tube 40 in question. XX ′ and is located above the axis in the embodiment shown in the figure.

In practice, as shown in FIG. 2, the indexing means comprises, for example, a ball 76, which is held by a screw 78 traversing the flange 32 in the radial direction and is installed inside the flange 32. Cylindrical rotating drum 2
A force is applied by a compression spring 80 against the cylindrical outer surface of the second cylindrical portion 33. An axial groove 82 having an arcuate portion and formed on the outer surface is provided with a ball 76 when one of the storage tubes 40 is positioned at the angular position defined above.
To support and accommodate.

[0032] Thus, for example, a circle of thick wall 16 by cylindrical blind formed on the outer surface hole (blind hole) in engaged spanner cylindrical body portion 33 (abbreviated Figure)
If the operator controls the rotation of the column rotating drum 22, a ball 76 in the groove 82 corresponding to the storage tube 40 through which the radioactive source is to be introduced or from which the radioactive source is to be removed is penetrated. Upon hearing the evoked click, the operator stops turning the body.

Finally, the storage cask 14 has a protective cap 86, shown in phantom in FIG. 1, which covers all the protruding parts of the cylindrical rotating drum 22, the flange 32 and the sleeve 50. Wall 16
Is detachably fixed to the front surface 20.

The partition 10 is provided with an engaging member in the form of a flange 88 so that the radioactive source can be carried between the enclosure defined by the partition 10 and the storage cask 14. And the flange is
As shown in, for example, the partition wall 10 by screws 90
It is fixed to the outer surface. It is important to note that when the cask 14 is mounted on a trolley or carriage 72, the axis of the flange 88 is the axis XX 'of the cask 14
That is,

On the outer surface of the engagement member, the flange 88 has an annular portion. The annular portion is a cylindrical portion of the cylindrical rotating drum 22 protruding from the end surface 94 of the flange 32.
A cylindrical cavity 92 open to the outside of 33 and its appendage is defined internally.

A straight guide tube 96 traverses the wall 10 and the flange 88 so as to appear at the bottom of the cylindrical cavity 92 above the axis XX '. The axis of the guide tube 96 is disposed on a vertical plane passing through the axis XX ', and the end of the storage tube 40 is disposed at a length equal to the distance away from the axis XX'. Thus, the guide tube 96 is provided in the storage cask 1
4 is arranged so as to be in line with the storage tube 40, which is precisely located by the indexing means provided on 4.

When one of the storage tubes 40 is on the extension of the guide tube 96, a further blind hole 98 is provided so as to emerge into the cavity 92 in front of each of the other storage tubes 40 in the cask 14.
Are formed on the inside of the wall 10 and the flange 88. Front 94
When the cylindrical portion 33 of the cylindrical rotating drum 22 protruding from the cylindrical sleeve 92 is received and supported in the auxiliary cylindrical cavity 92, the blind hole 98 has a protective sleeve 5 sealing another storage tube 40.
0 can be accommodated.

It should be noted that when the cylindrical portion 33 of the cylindrical rotating drum 22 projecting from the front surface 94 is accommodated in the cavity 92, the inclined portion 100 formed at the entrance of the cavity 92 is fixed to the stopper pin 54. By cooperating with the hemispherical end, the stop pin 54 is automatically superimposed. End face 1 whose front face 94 forms the contact face of flange 88
02 is in contact with the radioactive source 44 in the storage tube 40
Is therefore automatically released.

Finally, the installation according to the invention comprises a second cable section 104, which is connected to the guide tube 9
6 and is equipped at its end with a coupling device 106 which is fixed to an auxiliary coupling device 108 mounted at the end of the cable section 46 carrying the radioactive source 44. Coupling device 1
06 and 108 are constituted by a high-speed screw or a bayonet joint or a mechanism equivalent thereto.

Next, with reference to FIGS. 3 and 4, an example of use of the storage facility according to the present invention for replacing a radioactive source normally arranged inside the sealed body 12 will be described.

As shown in FIG. 3, initially, the storage cask 14 is carried on the trolley 72 (see FIG. 1) near the engagement flange 88. After removing the protective cap 86, the operator manually rotates the cylindrical rotary drum 22 so as to position the empty storage tube 40 at the front of the guide tube 96 using the above-mentioned indexing means.
Next, the worker removes the protective sleeve 50 from the empty storage tube.
Is removed and the cask 14 is engaged with the engaging flange 88 by moving the trolley 72 on the rail 74 so that the cylindrical portion 33 of the cylindrical rotating drum 22 passes through the cavity 92 of the flange 88.

In the position shown in FIG. 4, the operator is operated by means of a remote control arranged in the enclosure, the assembly constituted by the radioactive source 44 to be replaced and the cable section 46 associated with the radioactive source. And the device 106
And 108 push the cable portion 46 and the associated cable portion 104 back. Following this push, the radioactive source 44 passes through the guide tube 96 and moves through the storage tube 40 which is an extension of the guide tube 96 until the radioactive source 44 contacts the bottom of the storage tube 40 (arrow F).

It should be noted that the replacement of the radioactive source and its associated cable section is not damaged by the stop means 52. Therefore, while the cylindrical portion 33 of the cylindrical rotating drum 22 is inside the cavity 92, the stopping means 52 loosens the locking pin 54, and the locking pin 54 is pushed back.

Next, in order to release the cylindrical protruding portion of the cylindrical rotary drum 22 from the cavity 33, the operator operates the cask 1
Move the trolley 72 carrying 4 slightly back. While the cask 14 is moving, the pushing force from inside the cell 12 against the cable portion 104 is maintained until the stop pin 54 exits the cavity 92. Accordingly, the locking state of the cable portion 46 is determined according to the function of the spring 64 acting on the locking pin 54 corresponding to the cable portion 46.
Automatically maintained.

Under these conditions, the coupling device 10
6, 108 are easy to use and can be removed by an operator. The protective sleeve 50 of the storage tube 40 to be used is immediately put in place. Next, the operator can introduce a new radioactive source into the enclosure 12. To do this, the worker must manually re-
The column rotating drum 22 is rotated to move another storage tube 40 containing the new radioactive source secured to the cable section 46 over the extension of the guide tube 96. After removing the protective sleeve 50 from the storage tube 40, the operator operates the coupling device 1 of the cable section previously introduced into the guide tube 96.
06, the coupling device 108 is coupled.

Next, the cask 14 is engaged with the flange 88. This engagement allows the cable portion 46 to move freely. The action from within the enclosure 12 allows the operator to carry new radioactive sources into the interior of the enclosure.

To complete the operation, the operator again moves the trolley carrying the storage cask 14 rearward, and in addition to the protective cap 86, returns the protective sleeve 50 of the corresponding storage tube 40 to an appropriate place. The spent radioactive source is transported by the cask 14 to another location.

It should be noted that during these operations,
The configuration in which the storage tube 40 on the cask side is bent inward protects the worker against radiation emitted by the radioactive source.

Obviously, the invention is not limited to the embodiments described above, but includes all variants. Therefore, a cylinder within the size appropriate for the size of the storage cask
The number of storage tubes 40 of the rotating drum 22 may be two or many. Further, the stop means 52 can be variously configured, and the slide type stop pin is connected to the pivot element (pivo
ting elements). In addition, the pursuit of a simpler and less expensive arrangement has resulted in a storage cask configuration in which the rotation of the body of the cylindrical rotary drum 22 is easily controlled manually, but also by a motor. Finally,
If the cask can be arranged in a system in which the cask is easily aligned with the engagement device, the common axis of the cask and the engagement means provided on the enclosure wall is oriented horizontally. Is not necessary.

[0050]

As described above, in the equipment according to the present invention, the worker is placed at the bottom of each of the tubes because of the inward bending of the storage tubes housed in the rotating drum of the cask. Protected from radiation from radioactive sources. Thus, the worker can safely perform many tasks before and after transferring the radioactive source between the cask and the enclosure.

Furthermore, the rotating drum of the cask has several storage tubes, by means of which one or more (three in the present case) radioactive sources can be replaced using a single cask, These operations were not possible in the past.

[Brief description of the drawings]

FIG. 1 is a side view of a partial longitudinal section of a radioactive source storage facility according to the present invention.

FIG. 2 is a sectional view taken along the line II-II of FIG.

FIG. 3 is a side view in longitudinal section outlining one step taken during the replacement of the radioactive source by the installation of FIG. 1;

FIG. 4 is a side view in longitudinal section outlining one of the steps taken during the replacement of the radioactive source by the installation of FIG. 1;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 12 Sealing body 14 Cask 22 Cylindrical rotary drum 40 Storage pipe 46 1st cable part 88 Engagement member 96 Guide pipe 104 2nd cable part

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-60-163000 (JP, A) JP-A-49-64800 (JP, A)

Claims (10)

(57) [Claims] 1. A storage cask including a rotating drum disposed therein with at least two inwardly curved storage tubes emerging at one end of the rotating drum, and at least one first carrying a radioactive source at a first end thereof. a first cable portion, the cable portion housed together with the radioactive source in one of the storage tube, the end of the second end is a rotating drum of the cable portion when the radioactive source at the bottom of the storage tube a first cable portion configured to protrude from the facilities for storing and prevention means for stopping the cable portion of the rotary drum in association with each storage tube, a radioactive source, characterized in that it consists of. 2. The storage tube of claim 1, wherein each storage tube is mounted on a wall of an enclosure capable of containing a radioactive source such that the storage tube is aligned with the guide tube and engagement member across the wall and the rotation of the drum. The engaging member, one end of which can be engaged, and a second cable portion housed in the guide tube, the first end of which can be connected to the second end of the first cable portion. Equipment for storing radioactive sources. 3. The rotating drum has one end protruding from an end face of a storage cask and having a cylindrical portion in contact with a contact surface of the engaging member, wherein the cylindrical portion penetrates an auxiliary cylindrical cavity formed in the engaging member. The facility for storing a radioactive source according to claim 2, characterized in that: 4. When the one end of the rotating drum is engaged with the engagement member, the stop pin is associated with an element cooperable with the engagement member to release the fixed state of the first cable portion. The facility for storing a radioactive source according to claim 3, wherein the radioactive source is stored. 5. The rotating drum is slidably received in a hole formed in the one end of the rotating drum and is a stop finger that intersects one of the storage tubes, wherein one end of a stop pin terminates in the one end of the rotating drum. When flush with the outer surface of the cable, the passage formed in the stop pin is aligned with the storage tube and the resilient means is used to move the stop pin toward the stop position of the first cable section. 5. A facility for storing radioactive sources according to claim 4, characterized in that it acts on a stop pin, by means of which the end of the stop pin projects from the outer surface. 6. The radioactive source according to claim 2, wherein the storage cask is carried so that the axis of the engaging member is aligned with the axis of rotation of the rotary drum, and the trolley runs on rails. Equipment to do. 7. A facility for storing a radioactive source according to claim 6, wherein one of the storage tubes comprises means for determining the rotation of the rotary drum which determines the position in line with the guide tube. . 8. At least two detachable detachable ones which can be fixed to said one end of the rotating drum over the extension of each storage tube so that the second end of the first cable section housed in said storage tube can be sealed. The facility for storing a radioactive source according to claim 7, comprising a sealing sleeve. 9. An engagement member at least one of which is capable of supporting the protective sleeve when one end of the rotating drum is engaged with the storage tube from which the sleeve has been removed and the storage tube is aligned with the guide tube on the engagement member. 9. The facility for storing a radioactive source according to claim 8, comprising one blind hole. 10. The facility for storing a radioactive source according to claim 1, further comprising a removable protective cap that can be secured to a transport cask around one end of the rotating drum.