FR2613485A1 - DEVICE FOR COLLECTING SAMPLES OF RADIOACTIVE AND / OR TOXIC SUBSTANCES FROM PROCESS COMPONENTS - Google Patents

Abstract

THE INVENTION RELATES TO A DEVICE FOR THE TAKING OF SAMPLES OF RADIOACTIVE OR TOXIC SUBSTANCES OF COMPONENTS IN PROTECTED AND INACCESSIBLE CELLS, WITH EXAMINATION STATIONS, SAMPLING, TUBULAR DUCTS BETWEEN THEM AND A MOBILE SUPPORT WHICH IN THE DUCTS CONTAINERS FILLED WITH SAMPLES TAKEN. ACCORDING TO THE INVENTION, THE SUPPORT 10 IS ELECTRICALLY DRIVEN BETWEEN THE SAMPLING 35 AND EXAMINATION STATIONS, THE DUCTS 41 OF SEVERAL SAMPLE TAKING POINTS LEAD TO A HEAD 40 OF THE STATION 35, THE SUPPORT 10 SHOWS A COUNTER- HEAD 25, AND BY A RECTILINE DISPLACEMENT OF THE SUPPORT 10 VIS-A-VIS THE HEAD 40, THE CONTAINERS 20 ARE CONNECTED TO THE CORRESPONDING DUCTS 41. THE INVENTION APPLIES IN PARTICULAR TO NUCLEAR TREATMENT FACILITIES.

Description

The present invention relates to a device for sampling

  samples of radioactive and / or toxic substances from process components, which are in protected and inaccessible cells, with a test station placed away from the process components, with a sample collection station placed near process components, with a system of tubular conduits between the test and sample stations and with a movable support in the tubular duct system, which contains sample containers that are filled with samples at the station sampling. Such a device is known from EP-A1-0093609. There, it is proposed, for a facility for nuclear reprocessing, to undertake sampling of the process liquid within the facility itself. For this purpose, a system of tubular conduits resembling a pneumatic tube is provided, which leads from the hot cell to an analysis station. A bottle carrier for sample bottles is transported by compressed air into this tubular conduit system. At the sample collection station, inside the hot cell, a remotely controllable manipulator is placed in a box, which removes the sample bottle from the support, transports it to a point of capture and presses it there. This handling technique is not suitable for nuclear fuel reprocessing plants because the two process cells receiving and protecting or isolating the process components are provided with a large number (about 80) of chassis for the components and there is, by chassis, a

  very large number of sampling points.

  At each of these numerous sampling points, it would be necessary to provide, according to the known device, each time a device of the manipulator type for the unloading of the sample bottles and the docking.

to a needle head.

  Another disadvantage of the known device can be seen in the fact that, as a means of transport for the bottle holders, air is used. The hot cell of an installation for reprocessing should be insulated as much as possible, which means that the shielding should not be, or as little as possible, interrupted by radioactive currents. Air as a means of transporting cells from the interior to the outside would be detrimental to this concept and would cause leakage problems and the cell's atmosphere could escape from the isolated cell into the premises.

stewards or in the open.

  In general, in nuclear installations, particularly in facilities for the reprocessing of irradiated fuel elements from the nuclear reactor, many samples of the process streams must be continuously examined in a central laboratory. Traditionally, pipelines depart from the shielded hot cells where chemical process components, sample points are located at a remote central laboratory, or at a sample collection gallery outside the hot cell. From this gallery, samples drawn, sample bottles, by needle heads, are guided by appropriate transport systems, to the radiochemical workstation in the central laboratory. In this case also the dividing wall between the hot cell and the sample taking rack is constantly

  "interrupted" by radioactive currents of the process.

  In US Pat. No. 4,493,792 a device is described in which the sample station is outside the hot cell but is, however, considerably shielded. In this case also the sampling station contains a device of the manipulator type. A sample bottle body is introduced laterally into the sampling station, the manipulator then passes, by means of a needle, a membrane of the bottle and introduces, through the needle, the desired sample into the sample station. bottle. In this case also arises the problem described above, that radioactive currents of the process

come out of the hot cell.

  The present invention therefore has the task of improving the device of the prior art above so that it is distinguished, with a higher capacity, by a minimum danger of leakage of

radioactive constituents.

  This task is solved by a device in which the support of the sample containers is guided, by means of an electrical drive, between the sampling or sampling station and the examination station. Pipes go from several sample points to each process component, to a common head of the sample station, and the carrier has a counter head, the head and the counterhead being configured so that by a simple rectilinear displacement of the support vis-à-vis the head, the sample containers are connected to the corresponding conduits so that the samples

  may be introduced into the containers.

  Thus, in the case of the present invention, the taking of samples takes place inside the hot cell. Only samples arrive outside, but no process flow. Since, in the present invention, the bottle support can be driven by electrical control, there is no appreciable exchange of air between the hot cell and the environment. As the hot cell is normally maintained at a slight depression, however, a little air flows inwards. Sampling occurs in an extremely simple manner, since the docking of the support or respectively of the sample container occurs exclusively by a linear movement of the support. No manipulator or remote-controlled device

additional is necessary.

  It is also important that at a sample station, several samples of various liquids can be taken at the same time. This allows a very significant decrease in the price of

sampling stations.

  Another important advantage of the invention lies in the fact that the individual components of the sampling system can be easily changed, even under the necessary conditions of remote control, thanks to the remote control systems present.

  anyway in the hot cell.

  Decontamination of the support, sample containers and the entire sampling system is possible in a very simple way, which makes it possible to further reduce the danger of

  training of radioactive materials.

  Finally, it is relatively easy to remedy disturbances such as, for example, a support that has remained

  stuck in the system of tubular conduits.

  The invention will be better understood and other purposes, features, details and advantages thereof

  will become clearer during the description

  explanatory text which will follow with reference to the accompanying schematic drawings given solely by way of example illustrating an embodiment of the invention and in

which: -

  - Figure 1 shows an exploded view of the device according to the invention; - Figure 2A shows the drive part of the support; FIG. 2B shows the part of the support supporting the sample containers; FIG. 2C shows the needle head portion of the support; - Figure 2D shows the sampling station; FIG. 3 shows a diagram of the configuration of the bores (plan view) of a sampling station of FIG. 2D; Fig. 4 is a sectional view of a valve in the sampling station, and Fig. 5 is a perspective view of a portion of a hot cell with process components and the conduits for the sample collection system

according to the invention.

  Referring first to Figure 5. In a hot cell of a facility for nuclear reprocessing, there are several chassis 2 o are disposed components 3 of the process. In the components 3 are performed the process steps for reprocessing. The components 3 are connected to each other according to the path of the process streams, by means of

tubular conduits.

  Samples of the process fluids must be collected at various locations in the reprocessing process. In the exemplary embodiment of the figure, the two chassis 2 shown each have a sampling station 4. Tubular conduits, not shown, depart from the individual components 3 of each frame, to an affected sampling station 4, each process fluid thus constantly circulating during normal operation in these tubular conduits (i.e. in times when he

  there is no sampling).

  Pipes 5, which pass through the wall 6 of the hot cell 1, go to each sampling station 4. These ducts 5 are combined in a collecting duct 9 by means of remotely controllable connections 8, in a passage 7 situated outside the hot cell 1, leading to an examination station (not shown) placed outside the hot cell. 1. This test station corresponds to

  central laboratory cited above.

  In lines 9 and 5, a sample carrier 10 is movable between the examination station and the sampling stations 4. By changing the connections 8, a support 10 can be directed to a selected sampling station 4. Several supports 10 can also be in simultaneous use, as long as minimum distances determined

  are held between two moving supports.

  Reference is now made to FIG.

  It shows an exploded view of a portion of the pipe 5 shortly before the sampling station, and it is understood that the pipe sections shown individually form a tight and attached pipe. In this conduit, a carrier 10 is movable, which support 10 has also been cut into

  three components 10a, lob and 10c for its representation.

  The three components 10a to 10c actually form a single body. The cut-away portion 10a represents the driving portion, the portion 10b the portion of the support of the sample containers and the portion 10c the portion of

needle head of support 10.

  Inside the pipe 5 is a continuous rail 11 in the form of a flat plate with a guide groove 12. In the guide groove 12 are placed electrical lines 13 on which a carriage 14 is rubbed. in the training part 10a. Through these electrical conduits, the support 10 receives control signals for its movement as well as, where appropriate, electrical energy for its drive. In addition, the support can also obtain its power supply by means of batteries that it carries. In the training part 10a is further provided a drive unit 15 which has an electric motor, if necessary a transmission and a pair of wheels 16 and a back-pressure roller 17. The pair of wheels 16 moves on the rail 11 while the counterpressure roller 17 rests on the side of the inner wall of the pipe 5 which is opposed to the rail 11. The mentioned batteries can be arranged in a box 18 placed at the rear end of the support 10, as well as the control electronics for controlling the unit

  drive 15 (see FIG. 2A).

  The portion 10b of the sample holder of Figure 2B is firmly connected to the portion 10a. This

  Part 10b may also have pairs of wheels.

  The essential part, however, is a magazine 19 which can receive several sample containers 20 or sample bottles in parallel chambers, which containers are directed parallel to one another and with their longitudinal axis parallel to the other. main axis 21 of the support 10. The magazine 19 is retained in the casing 22 'of the support 10 against any rotation, so that the orientation or the position of each sample support 20 is unambiguously established (in cooperation with the unambiguous position of the support 10 due to the guide groove 12). The magazine 19 furthermore has a central opening 22 which has lateral enlargements or bayonet slots 23. In addition, small stop recesses 24 are provided on the inner lower side of the central opening 22, which is

  known in general, as bayonet locks.

  The central opening 22 with the lateral enlargements 23 and the stop recesses 24 serves to connect a needle head plate 25 (FIG. 2C) which is part of the head piece 10C, to the magazine 19. The head piece 10C needles contains said needle-head plate, where is reported a central tube 26 with pins 27. This tube 26 with the pins 27 is introduced into the central opening 22, and the needle-head plate 25 is then rotated to that the lugs 27 engage in the retaining noses 24, thus ensuring an unambiguous relative position in rotation between the plate 25 and the magazine 19. A compression spring 28 further surrounds the central tube 26, which 'press against the back of the

  plate 25 and the front side of the magazine 19.

  The needle head plate 25 has several pairs of needles 29, one pair of needles per container 20 of the sample. The containers of the sample have, at their side facing the pair of needles 29, a membrane 30 which can be traversed by needles 29. In the normal state of transport, the tips of the needles 29 are at a certain distance As soon as the plate 25 of the needle head is pressed, against the force of the spring 28, in the direction of the magazine 19, the needles 29 pass through the membrane 30. It is clear that thus the plate 25 is movable forwardly and rearward axially vis-à-vis

boot 22 'of the support 10.

  The other ends of the needles 29 pass through the plate 25, which has openings on its outer side or respectively, which communicate with the needles. Each time, two of these openings 31 open into a recess 32 in

  the outer side or respectively front of the plate 25.

  On the outer side or respectively before the plate 25 of the needle head is further provided a central opening 33 which is in connection with the central tube 26. The central tube 26 has a plurality of radial openings 34 which, looking in the axial direction , are approximately in the area of the points of the needles 29. These are openings of out

a decontamination liquid.

  Referring to FIG. 2D, the sample station 35 will now be described. At the end of the pipe 5 is welded an annular flange 36 to which is attached a corresponding flange 37 of the bo! Tier 38 of the sampling station by means of a connection 39 by crampons.

Tightening.

  The sample station has a valve block 40 to which are attached a number of pairs of lines 41a-41f. In these pairs of pipes circulate the liquids of the process. Pairs of pipes are also connected to each component 3 (FIG. 5). Each pipe of a pair 41 opens through holes 42 in the valve block 40, in a corresponding valve chamber 43 and so that the holes 42 open at separate points in the valve chamber 43. Each valve chamber 43 has an extension 44 o are guided, so as not to rotate, the valve bodies 45. The valve bodies 45 are movable in the axial direction of their central axis 46 and can take two extreme positions. In a first extreme position, where the valve bodies partially protrude from the valve block 40 in the direction of the support 10, an annular groove 47 of the valve body 45 is directly opposite the point of mouth of the bore 42, so the fluid of method can flow from a bore 42 to another bore 42 of a pair of pipes 41. This position

  will be hereinafter referred to as "closed position".

  At the other limit position of the valve bodies, in which these are pushed further into the valve block 40, this circulation is interrupted. In contrast, the process fluid flows from a bore 42 through a recess 48 and a bore 55 from said recess 48, parallel to the central axis 46, into the valve body 45 to an opening 50 (FIG. 4). The other bore 42 for the return line is also facing another recess 48 'with bore 55' and opening 50 'of the valve body. The two openings 50 and 50 'of the valve body 45 are directed so as to be directly opposite the two openings 31 of a pair of needles 29 in the support 10. This also gives a flow communication between the pairs 41, the pairs of needles 29 and the

containers 20 of the sample.

  The valve block also contains a central passage bore to which is attached on both sides a rinsing line 51. The "inner" part, that is to say directed towards the support 10, of the pipe of rinse 51 has a rinsing head 52 which has a plurality of radial bores 53 which are aligned with the bores 34. The rinsing head 52 is sized to fit into the opening

central support 10.

  The mode of operation of the device according to the invention will be described below. For sample taking, the carrier 10 is sent to the examination station with sample coded containers. The coding is any automatically readable code, for example a bar or color code, a magnetic code, etc. The sample containers are closed in a sealed manner, by their opening side, by the membrane 30. Then, the plate 25 of the needle head is put in place and fixed by the bayonet lock (26, 27; 22, 23, 24), the needles 29 not yet passing through the membrane 30. Then, the support is introduced in the collecting duct 9. Depending on the position of the connection 8 (FIG. 5) and being guided by the electrical conduits 13, the support 10 moves, by electrical drive, to a chosen sampling station 4. While As the support approaches the sampling station, its central opening 33 passes over the rinsing head 52 until the bottoms of the recesses 32 come into contact with the front sides of the valve bodies 45. By further movement forward of the support 10, the plate of the needle head 25 is moved against the force of the spring 28 in the direction of the magazine 19. The pairs of needles 29 then pass through each membrane of their affected sample container, so the tips of the needles are inside the sample container. During a further movement of the support, the valve bodies are moved from their closed position to their open position, the circulation link between the pairs of conduits 41 is interrupted and the flow through each container 20 from

  the sample occurs, so that it is filled.

  It should be recognized that the entire docking of the support on the sampling station occurs exclusively by the advance movement of the support. No other remote-controlled "manipulation" is necessary. The separation occurs in reverse. By the backward movement of the support (movement towards the rear), the valve bodies 45 return to their closed position and close the communication

  flow between the needles 29 and the pipes 41.

  Upon further backing of the support, the plate 25 is again moved away from the magazine 19 by the spring 28 and the needles leave the sample containers 20. The support can then be brought back to the examination station by being electrically controlled, and thus carry with it a number of samples

of various kinds.

  We can see, by the above description,

  that in the case of the invention, the sample containers for taking samples no longer have to be extracted from the support and that all the sampling is exclusively "controlled" by the movement of advance and backing of the support 10. No further action is necessary to withdraw the samples. During docking or separation, it is also possible to perform a decontamination of the support, to prevent any unnecessary entrainment of radioactive and / or toxic substances. For this purpose, the rinsing line 51 is used with the rinsing head 52 and the bores 53 and the central tube

26 with the holes 34.

  Preferably, the decontamination occurs during the separation and at the phase of the return movement of the support 10, where the valve bodies are already in their "closed position", but where the needles have not yet emerged from the sample reservoirs . This is where mutual contaminations can best be avoided. In this phase, a remotely controlled liquid for decontamination is introduced through the rinsing line 51 to the rinsing head 52 where it leaves, through the bores 53, in the central tube 26, and from there through the bores 34 to decontaminate the The outer side of the plate 25 can also be decontaminated, as well as the space in front of the valve block 40, depending on the duration of the supply of the decontamination liquid.

  i.e. the valve bodies 45.

  For the flow of decontaminating liquid

  An additional pipe, not shown, may be provided, which opens into the space of the pipe 5 in front of the valve block 40. If the sampling station 35 is arranged so that its axis is vertical, the The rinsing line 51 may also be in the form of a double-walled tube, the inner tube then serving for the supply of decontamination liquid while the outer tube serves as a "second treatment line" for the evacuation of the liquid.

decontamination liquid.

  Complete decontamination of the pipe system (9.5) is also possible and is required from time to time. For this purpose, a separate vehicle can be placed in the tubular conduits and moved by a decontamination battery which has a pressure bottle with decontamination liquid and sprays it in front of it. This vehicle passes through all the tube sections. After the return of the vehicle, a drying process is then necessary to ensure the sliding contact or the transmission of energy for the support. For this purpose, a drying gas may be sent from the test station through the tubular duct system, which flows, through the

  described reprocessing line, in the hot cell.

  The following will be explained with reference to FIG. 4, further details of the valves. In the schematic sectional view, one can see the valve block 40 with valve body 45 in place as well as the two holes 42 assigned to it, which open into the valve chamber 43. The valve body is pressed by a spring 54 at its limit position, wherein its annular groove 47 produces a flow connection

between the two holes 42.

  It should be mentioned here that the sum of the forces of the springs 54 for the valve bodies 48 is more

  important than the force of the spring 28 in the support 10.

  It is thus ensured that at docking, the valves will open only when the needles 29 have passed through the corresponding membrane 30 and that, inversely, at separation, the valves will close before the

  needles do not withdraw from sample containers.

  Figure 4 further shows, clearly, the recesses 48 and 48 'of the valve body 45, which open through axial bores 55 or respectively to the openings 50 or 50' on the outer side of the valve bodies. If the valve body is pushed against the force of the spring 28, inwardly, in the valve block 40, a bore (left in FIG. 4) is connected in flow communication with the opening 50 and the other hole 42 (right on

Figure 4) with the opening 50 '.

  Since the apertures 50 and 50 'must be exactly aligned with the apertures 31 of the needle plate 25, the valve body 45 must be guided in the valve block in an exact, rotatable manner. There are in this case various possibilities. On the one hand, the extension 44 and the cutout 56 which corresponds to it in the valve body can be unambiguously defined by a shape

  appropriate (eg rectangle, triangle, etc ...).

  On the other hand, it can also provide a link to

  clamping spring with dovetail guide.

  Other possibilities of construction, which allow an axial displacement of the valve body, but prevent its

rotation, can be used.

  Electrically driven brackets must move at a relatively high speed through the tubular conduit system. In such a way that the docking does not occur with too much "violence", however, explorable marks (mechanical, optical, electrical, magnetic, etc.) can be provided in front of each sampling station, which are recognized by sensors of the support, following which the speed of advance of the support is slowed down

  or respectively a braking process begins.

  In the case of disturbances of the sampling system, the following measures can be taken: the sampling station itself can be changed simply by the remote control systems placed inside the hot cell,

and that by the usual points.

  In addition, the portion of the pipe 5 placed inside the process cell, directly in front of the sampling station, may have the shape of an exchangeable flying tube, so that it can also be easily exchanged in remote control conditions. If a fault occurs during docking or separation, this flying tube can also be exchanged, remotely, with the support 10 located inside it. If a case of failure occurs in transporting the support within the pipe system, an electrically controlled recovery box may be conducted through the tubular conduit system to the defective carrier, which drives the same. on the way back to the examination station. Coupling can occur by automatic coupling, magnetic or other forces. If this is not successful, the recovery box may push the defective media forward, to a selected sample collection station 4, or the media may be remotely exchanged, together with

the flying tube.

  If this does not succeed either, for example because the support is completely stuck in the system of tubular conduits, we must then determine the exact position of it and then we can also, by remote control tools, exchange the corresponding tube section with the support it contains. For this purpose, the system of tubular conduits is formed of sections of tubular conduits which are

bridled to each other.

  As previously indicated, all of -

  tubular pipe system is under a slight overpressure while the hot cell is at a slight depression, so unintentional entrainment of radioactive or toxic substances in the open air can be avoided. In addition, the tubular pipe system must go from the outside to the hot cell with a slight slope so that during the decontamination process of the whole system described above, the decontamination liquid always returns to the

hot cell.

  Inside the system of tubular conduits can be arranged various sensors, with the help of which one can determine the exact position of a support. For this purpose, induction lines, or other known sensors which indicate the

  presence or absence of support.

  Finally, reference is still made to Figure 3 which

  shows a pattern of drilling holes in the valve block.

  Each pair of lines 41a to 41f is shown along with their flow connection through the holes with the corresponding valve chambers 43a to 43f. Finally,

  Central rinsing pipe 51 can also be seen.

? 613,485

Claims (13)

  1. Device for taking samples of radioactive and / or toxic substances from process components which are arranged in protected and inaccessible cells with a test station disposed away from the process components, with a sampling station located near the process components, with a system of tubular conduits between the test station and the sample collection station and with a support moveable in the tubular conduit system which contains sample containers which are filled with samples at the sample collection station, characterized in that the support (10) is movable by being controlled by an electric drive (15) between the sampling station (35) and the station in that pipes (41a-41f) go from several sampling points to the individual process components (3). ) at a common head of the sample collection station (35) and in that the carrier (10) has a counter head (25), the head 40 and the counter head (25) being configured so that by simply moving the support (10) linearly with respect to the head (40), the sample containers (20) are connected to the affected conduits (41) so that samples   can be introduced into the containers (20).   2. Device according to claim 1, characterized in that the counterpart (25) of the support (10) is configured as a plate (25) with movable needle heads relative to the stacker (22) of the support (10) and has needles (29) which, at the docking of the support lg (10) on the sampling station (35), passes through a membrane (30) of the corresponding container of sample (20).   3. Device according to any one of   preceding claims, characterized in that the   support (10) is guided so that it can not rotate   in the system of tubular conduits (5,9).   4. Device according to any one of   preceding claims, characterized in that the   sample containers (20) have a coding   allowing their automatic recognition.   5. Device according to any one of   preceding claims, characterized in that the head   (40) of the sampling station (35) has, in the idle state, closed valves (45) which, on arrival of the support (10), open so that the pipes ( 41) come into flow connection with   corresponding sample containers (20).   6. Device according to claim 5, characterized in that each valve (45) is assigned a pair of pipes (41a-41f) and the rest position of the valves (45), a circulation of the treatment fluid in the Couplings of a pair (41a-41f) are possible, while in the open position of the valves (45), the circulation through the corresponding sample container (20) occurs, thereby filling it. 7. Device according to any one of   claims 5 or 6, characterized in that the bodies of   valve (45) are movable axially in the head in the form of a valve block (40), have at their portion located furthest inside the block (40), an annular groove (47) and at with their outermost section in the valve block (40), two recesses (48, 48 ') separated from one another in flow, the recesses (48, 48') being connected by means of axial bores (55, ') which open, on the front side of the valve body (45), into openings (50, 50'), these openings being aligned with corresponding openings (31) of the needle plate (25) and so with the needles (29).   8. Device according to claim 7, characterized in that the valve bodies (45) are guided in the valve block (40) so as not to to be able to turn.   9. Device according to any one of   Claims 5 to 8, characterized in that the conduits   of a pair (41a-41f) open, through holes (42), in separate places and advantageously vis-à-vis, in a valve chamber (43), in which each   valve body (45) is movably arranged.   10. Device according to any one of   preceding claims, characterized in that the   needle plate (25) with needles (29) can be fixed by a bayonet lock (26, 27, 22, 23, 24) to a magazine (19) of sample containers (20) of the carrier (10) so that a relative position unambiguously defined in the direction of rotation about the main axis (21) of the carrier (10) between the needle-head plate (25) and the magazine (10) , can to be maintained.   11. Device according to any one of   preceding claims, characterized in that the   a needle-head plate (25) is preloaded to the magazine (19) by means of a spring (28), whereby at the rest position of the needle-head plate (25), the needles (25) are outside the sample containers (20) and that the force of the spring (28) is lower than the force required to   opening all the valves (45).   12. Device according to any one of   preceding claims, characterized in that the head   (40) of the sampling station (35) and the needle-head plate (25) of the support (10) each has an additional tube (51, 26) which at the docking of the support (10) at the sampling station (35) communicate with each other, the tube (26) in the holder (10) having outlet openings (34) for a decontamination liquid and these openings outlet (34) being arranged in such a way that the decontamination fluid leaving it reaches at least the point of the needles (29) and   the membranes (30) of the sample containers (20).   13. Device according to any one of -   preceding claims, characterized by a box   additional recovery unit with electric drive which can be moved through the tubular duct system (5, 9) and move a support (10) trapped in the tubular duct system (5, 9) towards the test station or advantageously in the direction of a sampling station (35), the section of the pipe (5) arranged directly before the sampling station (35) being   configured as a remotely exchangeable flying tube.