FR2857498A1 - Radioactive waste sorting and grading comprises use of overhead rail conveyor to transfer material through aperture in storage building wall - Google Patents

Abstract

The process uses a series of implements on an overhead rail conveyor (3) to carry waste material (4) to be sorted through an aperture in one wall of a building in which it is stored into one or more compartments (21a, 21b) separated from the building by a shutter (7). The conveyor rails are articulated and can be dismantled, and the implements, which are designed for a variety of operations, are selected from an external carousel system and made for quick fitting to holders carried by the rail. The implements are operated by a mechanical traction system (11, 14) e.g. of cables, belts or chains powered by motors (29) or power cylinders and controlled by sensors located outside the storage building. The external compartments (21a, 21b) have inner interchangeable protective coverings and are optionally equipped with sealed traps.

Description

2857498 1

  METHOD AND DEVICES FOR TREATMENT

OF VARIOUS RADIOACTIVE MATERIALS

  INSIDE THE PREMISES, THAN STORAGE SILOS OR BASIC NUCLEAR FACILITIES.

DESCRIPTION

  Field of the Invention The present invention describes a method and its implementation device. The process is intended to treat the various waste contained in a room, for example a storage silo, to sort, calibrate and cut to be able to put them in containers by category waste.

  In one application, this waste comes from the operation of nuclear power plants of the graphite gas type.

  The invention is applicable to all types of silos used to store operating waste from MAGNOX type nuclear power plants or waste from heavy water plants.

  The invention is both the devices described and the method that is explained. Devices that can be used, possibly with other methods.

  The implemented method has the advantage of being compact, it can be set up in transportable and removable premises.

  State of the prior art and problem posed Some destocking tests have taken place on nuclear installations. They all used sorting technology in the room itself with a robotic arm.

  The use of this technique has led to very long clearance times and a rate of equipment breakdowns very important. The number of maintenance interventions generated stakeholder contamination during maintenance due to various breakdowns and a very large volume of waste. The use of electrically powered equipment in premises containing flammable and explosive waste has led to the use of complex explosion-proof equipment.

  Ref: Br8892-02a-MP98 01/06/03 Sorting, in the majority of the processes used, in the room itself, from hatches existing or practiced in the roof of the waste storage premises, forced the construction of airlock over these hatches which overloaded the structure of the buildings at the risk of weakening them and generated additional waste related to the processes used. During and after destocking, sorting, packing and stuffing or containerizing, a radiological check is performed. Once the sorting and packaging operations have been carried out, the waste is evacuated to a stuffing zone or containerization zone.

  SUMMARY OF THE INVENTION The method consists of not sorting the waste in the room where it is, but to take out in bulk the various objects or waste contained in the room to a sorting room.

  To do this, one installs at the edge of the silo or the room to be treated, the various modules containing the devices able to achieve destocking. In the sorting room, the waste is tipped to a sorting area through a sizing tank whose purpose is to transfer a volume of waste small enough that it can be spread on a sorting mat. This part of the process makes it possible to limit the dose rate inside this sorting room, to reduce in the same way the fire risk in this same room, to avoid an avalanche effect that could fill a part of the room and make sorting impossible.

  This calibration bucket also has the role of separating the two premises tightly to sectorize potential fire zones.

  In this room, the waste is placed in a vibratory bin, the first aim of which is to homogeneously distribute the waste in the bin, and then when the sorting between the different types of waste is carried out, the bin vibrates harder to bring this waste. towards the firing area.

  The vibratory bin could be replaced by a treadmill or other device providing the function of transferring waste out of the sorting area. The solution of the vibrating tray has the advantage, compared to a treadmill to be sealed and thus to confine the contamination in the tray. It protects against contamination mobile elements such as cylinders and thus facilitates their maintenance.

  Ref: Br8892-02a-MP98 01/06/03 2857498 3 When the waste has been tipped in the sorting area, a sorting trolley comes out of the protected area and rejoins the premises.

  This truck supports a waste sorting device that can be constituted by a robotized or telehandled tool alone, or by a cabin allowing manual intervention or for sorting and packaging, assisted sorting of a robotic or robotic arm, a tool arm for all functions required during cutting and packaging operations.

  List of Figures The method, object of the invention, and the various devices used in the context of the preferred application according to the invention will be better understood on reading the description below, followed by several figures respectively representing: Figure 1A describes the sectional process; we can see the silo 2, the premises 21a and 21b.

  Figure 1B is the top view of these premises.

  Figure 1C positions the ID and IF sections.

  Figure 1D shows the positioning of the devices in silo 2.

  Figure 1E shows a tape of silo 2.

  The figure IF makes it possible to describe the routing of the sorting carriage. Figure 2A shows the calibration bin and its displacement.

  Figure 2B shows the sizing tray in plan view.

  Figure 2C shows the passage of rails 3 and cables 11 and 14 in the sizing tray.

  Figure 3 positions the calibration tank 7 relative to the sorting tank 5 and the EE section used in Figure 2A.

  Figure 4A shows the attachment of the tool 10 to the tool carriage 9. Figure 4B shows the attachment of the cables 11 and 14 to the tool carriage 9 and the guides 12a and 12b.

  FIG. 4C makes it possible to understand the principle of remote control of the pneumatic distributor 20 by the cable 14.

  FIG. 4C makes it possible to understand the remote control principle of a tool 57, 58 or 59 by the cable 14.

  FIGS. 5A, 5B, 5C make it possible to understand the principle of operation of the tool carousel 15.

  Ref: Br8892-02a-MP98 01/06/03 Figures 6A, 6B, 6C describe various tools among those possible to implement the method according to the invention.

  Figures 7A, 7B, to understand the operating principle of the clamp 18 or any other programmed complex tool.

  Detailed description of the use of the method according to the invention The invention consists of a method and devices for the treatment, sorting and repackaging of various radioactive materials 4 contained within premises 2 such as silos of storage or basic nuclear facilities.

  In one of the applications envisaged for the invention, the room to be treated is considered to be entirely filled with waste to be emptied. In this example, we will call the storage silo or silo 2 the room to be emptied of its waste. It is obvious that the method described for this case can be applied, possibly with certain adaptations, to multiple types of premises.

  The application case describes the is to understand the process and its benefits, but it is in no way limiting.

  The method consists in sorting the waste outside the room where they are, in a sorting room which is arranged against one of the faces of this room.

  The process is designed to be modular, portable and assembled on site. To do this, each function is assigned to a module. Only the elements to intervene in the silo are stored in the sorting room marked 2 in Figure N 1 A. The first step of the process is to install the different modules together. In the preferred application according to the invention, three marked modules 21a, 21b and 26 are distinguished.

  The module 21a comprises the control room, the airlock and the radiological control devices including control gantries, the ancillary room in which are stored, outside the radioactive area and out of the explosive zone, the various engines and pistons able to implement the different tools used to complete the process. This arrangement has the advantage of allowing easy maintenance of the installation and the use of standard equipment. This module also contains a part of the life base.

  Ref: Br8892-02a-MP98 01/06/03 The module 21b contains the sorting room and the airlock of the sorting trolley, the carousel of tools whose operation is explained by figures 5a, 5b, 5c, an airlock to the outside of this module provided to allow the possibility of entering or leaving the carousel tools, as well as the trolley maintenance room.

  This carousel contains various tools that can be used to empty the silo, to gather the different waste according to their categories or materials, to grind or break this waste.

  It can be seen in the foregoing description that only the module 21b is a modulus in a classified zone, that sectoring between the premises copies the separation of the functions.

  The different modules are assembled together and interconnected by an equipotential bond and to a ground well.

  The second step of the method consists of making a blind opening marked la in the silo, then to install a frame marked lb in Figure 2A. At this stage, the first concrete waste falls into the sorting bin marked 8 in Figure 3. This is already a first waste treatment.

  In the preferred application of the invention, the opening in the silo 2 is made in the upper part so as not to affect the mechanical strength of the room.

  Once the insert (or frame) located lb positioned and fixed in the blind opening marked la, one fixes the calibration tray marked 7 in Figures 2A and 2B. On the frame 1b, the wall of the silo 2 is completely drilled. This tank 7 constitutes a closure device between the sorting room 21b and the silo 2. This calibration tank constitutes both a fire and radiological sectorization. The insert lb strengthens the structure so as not to degrade the mechanical strength of the room. The practice of opening in the upper part of the room also ensures the tightness of this room and avoids infiltration.

  The third step of the process consists of making traps or using existing hatches in the roof of the silo 2 and then installing steps marked 27 in FIGS. 1A, 1B, 1C, 1D. These steps are sealed to confine the radioactive dust in the silo 2. One can see in FIG. 1E representing one of these steps, the marked rail rod 23 provided with its sealed blocking device 38, a sighting window marked 36, a Ref: Br8892-02a-MP98 01/06/03 2857498 6 viewpoint cleaner 64, a safety valve marked 37, an instrumentation pocket marked 35, a ventilation duct marked 8 which is connected to a collector The locating device 33 constitutes the remote control clamp rail clamp.

  These steps therefore make it possible to seal the silo 2, to set up an instrumentation to control the silo 2 without using explosion-proof or other classified materials entering the silo 2. The sighting window is used by optical fire detectors, an optical camera and a gamma-sensitive camera, external lighting.

  In the preferred application according to the invention, it can be seen in FIGS. 1B and 1C, the marked carriage 24 which carries the aiming window sensors in the aiming window. It circulates on a track marked 25 disposed on the roof of the silo 2 and on the roof of the various modules. With only one group of sensors embedded on the carriage 24, it is possible to follow the contamination of the various premises. By identifying and characterizing the various radioactive sources, the gamma-sensitive camera is a valuable aid in sorting waste.

  The fourth step of the process according to the invention consists in introducing the rails marked 3 into the silo 2 through the opening 1.

  The insert lb has rail-shaped passages and cables as shown in FIG. 3B. These passages are equipped with seals to ensure the confinement of the premises.

  The confinement of the materials to be sorted requires a powerful ventilation scheme. For this reason, in the method described, each classified zone is isolated or even sealed compared to the others. This makes it possible to ensure confinement of the radioactive materials in the silo 2 and the sorting room 21b.

  The rails, in the preferred application according to the invention, are I-shaped profiles. To introduce the rail into the rail-carrier, the upper part of this profile is introduced between the fixed rollers 63 and the jaws 65. blocking the rail in the rail holder, is moved, with a clamp 54, the rollers 54 down, and then blocks against the rail.

  The lower part of the profile is used as a raceway for the tool carriage 9.

  The rails are composed of sections which are interconnected by articulations marked 30. These joints allow to introduce the rails to Ref: Br8892-02a-MP98 01/06/03 from the sorting room, they also allow to modify the path of the tool carriage marked 9 on the rails 3.

  In this way, we will be able to empty the silo 2 by adapting the rails to the slope of slope according to the emptying of the silo 2.

  To make this change of slope, we add the necessary extensions to the rail rods 23. The design of the rail rods in several parts is required to reduce the risk of lightning of the installation. The love at first sight on such an installation could lead to the fire or even the explosion of the waste contained in the silo 2.

  The arrangement of the installation is shown in FIGS. 1A and 1D.

  On the installation as described, there is a cable marked 11 tractor of the tool carriage 9 and a remote control cable tools marked 14. The motor 29 identified in Figures 1A and 1 D, circulates the cable 11 between two positions which correspond to the travel distance of the carriage 9. The carriage 9 is hooked on the cable 11. A device 6 identifies the voltage of the cable 11. It circulates between the pulleys 22 and 32 driven by a motor 29. The cable tensioner 6 makes it possible, among other things, to maintain a constant tension and to dampen the blockages of the tools 10 in the waste 4.

  In FIG. 4C, the remote control cable marked 14 is fixed on the piece 13 of the tool holder 9, but flows freely between the pulleys 45 and 47. The tensioner 31 makes it possible to actuate the various actuators on the tools, for example the 20. This function is provided by the adjustment of the voltage on the remote control cable 14 which is fixed on a part 13. This actuates, in the proposed examples, a cam to produce a specific action directly, as proposed in FIGS. 6A, 6B, 6C, ie a pneumatic distributor marked 20 in the case of complex tools represented by FIGS. 7A and 7B.

  For this particular application, an air reserve 19 is embarked on the complex tool 10. In this case, the tension on the remote control cable 14 sets the position of the pneumatic distributor marked 20. The different positions on the distributor describe a logic sequential operation and thus constitute a mechanical remote control of a programmed pneumatic tool.

  This device can be used for several types of tools, we will quote for example the principle of a clamp identified 18 in Figure 7A whose functions of lateral displacement, descent, rise, gripping Ref: Br8892-02a-MP98 01/06/03 2857498 8 an object and relaxation of this object are ensured by the implementation of this principle.

  The fifth step of the process consists of removing the waste from silo 2. 5 To do this, we will, first, enter a first tool for pushing the waste in the silo 2.

  This tool will equalize the level of waste, then bring the tool to the opposite end of the silo 2, we will then down the chosen tool the height of a pass.

  The measurement carriage 24 will then make a characterization of the surface waste in the silo 2, then the chosen tool, for example that identified 57, will push a quantity of waste towards the calibration tank 7. This calibration tank then switches to the local sorting and pours its contents into the sorting bin marked 5.

  If, during the phase of bringing the waste to the calibration zone, a particular type of waste is detected or visualized, the waste tool will be released by actuating the remote control cable 14, which will move the piece 60 represented in FIG. 4D. The displacement of this part 60 will raise the selected tool, for example the tool marked 58. This operation will take the tool used out of the silo 2 and store it in its location on the carousel tool holder marked 15. The FIGS. 5A, 5B, 5C make it possible to understand how the tool reaches its location and how the new tool takes place on the tool carriage 9.

  In more detail, at the arrival of the tool carriage 9 in the sorting room, the tool carousel 15 descends the corresponding rail at the level of the rail 3 on which the tool carriage 9 moves.

  The device, which connects the tool holder 9 to the tool 10, is provided with a locking and unlocking device 66. To unhook the tool 10 from the tool carriage 9, the carriage is approached until the tool is actuated. stop 67 of the locking device 66 as shown in FIGS. 4A and 4B. The tool is then deposited on the carousel tool holder 15.

  This carousel is then positioned in front of the location of the new tool. The tool carriage 9 picks up the new tool, the stop 67 is activated again and the device 66 locks the new tool. This can be reintroduced into silo 2 to perform the required function.

  Ref: Br8892-02a-MP98 01/06/03 2857498 9 We can thus bring at all times, during the phases of retrieval, the tools available in the carousel. More particularly complex tools such as the clamp described in Figure 7A. This clamp can handle objects such as drums that may be present in the waste.

  The sorting tank 5 is, in the application according to the invention, constituted by a sheet metal bar provided with vibrating devices such as cylinders or motors with eccentric cams. These vibrating devices can be arranged below and on the sides of the tray.

  The sorting bin is vibrated to spread the waste.

  The advantage of a sorting tank system over a treadmill system is that it allows spreading of the waste which facilitates sorting, and secondly that the jacks are, unlike the rolling of a carpet, protected from dust. In the sorting of radioactive materials, this is a definite advantage for the maintenance and the reduction of the associated dosimetry.

  The sorting room has, in the preferred application according to the invention, a storage area by category of existing waste in the silo 2. This allows to store the sorted waste without risk of mixing. Waste from an area will then be removed from the sorting area by category and packaged by type in the containers in the appropriate area. Once the waste evenly distributed in the sorting tank 5, a sorting carriage 39 disposed on the rails 44 leaves the maintenance area 43. The pivoting of a switch 42 puts it on rails 40 and joins the sorting room 21B.

  This truck supports a waste sorting device which can be constituted, for example, by a robotic tool or tele-manipulated alone, or by a cabin for manual intervention during sorting and packaging operations. This cabin can be equipped, inter alia, with a sorting device assisted by a tele-manipulator arm or a robotic arm, as well as a tool-carrying arm adapted to all the functions required during the cutting, cutting and cutting operations. and thermal or mechanical chemical conditioning without limitation. During this sorting phase, the waste is distributed in the sorting bin 5.

  During and after all the operations necessary for the treatment and conditioning of the waste, as well as during the whole chain of filling or containerization, a radiological control is carried out.

  Ref: Br8892-02a-MP98 01/06/03 Once the waste sorting and conditioning operations in the sorting tank 5 have been carried out, the waste is evacuated to a stuffing area or to a container 51. fall into a crusher 49 and fill the barrels or containers that are evacuated via the conveyor belt 50 to the loading area 26.

  In phase 6 of the method according to the invention, the tools, between two work sequences, reach the maintenance areas where they can be washed or cleaned by special processes such as solidified carbon dioxide ball projection, and then possibly repaired.

  These washing areas are in the room containing the carousel, the sorting room itself and the maintenance room of the sorting cart.

  The washing residues are collected, filtered by recycling devices in these areas. The ultimate waste resulting from these recycling operations is impregnated in the process as particular wastes.

  In phase seven of the method, complex tools such as tool 59 in FIG. 6C make it possible to scrape the skin of the room itself in order to reuse the room or, combined with other tools, including those described in the preferred application according to the invention, to destroy and process the premises itself.

  The walls of the various rooms may be covered with waterproof protective coverings. If these protective coatings can not be decontaminated by simple means, in the folding phase of the devices used in the process, these protective coatings will be removed and impregnated by the process.

  The same goes for the cables that can be dismantled and stuffed. 35

Ref: Br8892-02a-MP98 01/06/03

Claims (1)

11 CLAIMS   1. Process for sorting, identifying, measuring the activity, sizing and packaging of radioactive waste, possibly heterogeneous, stored in storage rooms or in nuclear installations in order to decontaminate these premises , emptying them of their contents and putting them back to near their initial state, characterized in that it is carried out from an opening in at least one of the sides of the storage room (2) of the elements or waste (4) to be treated, to evacuate in the state, to one or more premises (21a), (21b) and (26) in which will be performed the operations necessary for their treatment, possibly separated from the initial storage room ( 2) by a member (7) allowing the confinement, their evacuation being done by means of one or more tools, for example (18), (57), (58), (59), moving to the inside the initial storage room.   2. Method according to claim 1, characterized in that the tool or tools, for example (18), (57), (58), (59), necessary for the transfer of waste (4) to the sorting room ( 21b) move along rails (3), hinged and dismountable, passing from the initial storage room (2) to the sorting room (21b).   3. Method according to claims 1 and 2, characterized in that it uses several tools, for example (18), (57), (58), (59), which can be chosen in an external carousel (15). at the initial storage room (2) or introduced from the outside by this carousel, then introduced into the initial storage room to perform the operations necessary for the transfer of waste (4) to the sorting room (21b).   4. Method according to claims 1 to 3, characterized in that the tools, for example (18), (57), (58), (59), all have an identical piece (10) for quick attachment to tool holder (9) sliding along the rails (3).   5. Method according to claims 1 and 2, characterized in that the rails (3) are held by rail-mounted devices (23) adjustable in height and articulated, fixed on taps (27), sealed against from the outside.   6. Method according to claims 1 and 2, characterized in that the tool or tools are moved and actuated by means of mechanical traction means (11 and 14) such as cables, belts, chains, or any other mechanical device conceivable, passing through the initial storage room (2) and the sorting room (2lb), the actuators of these mechanical traction means such as motors (29) or cylinders and the measurement and control sensors being located outside areas classified as explosive or radioactive.   7. Method according to claims 1 and 2, characterized in that the waste passes from the initial storage room (2) to the sorting room (21 b) via a sizing tray (7) which serves as a means separating, confining and sealing between these two premises of the installation according to the method.   8. Method according to claim 1, characterized in that the different functions are performed in separate modules which are external to the initial storage room.   9. Method according to claims 1 and 8, characterized in that all modules are provided with interchangeable internal protective coatings, possibly equipped with watertight hatches, sealed walls in the premises and organs allowing the partitioning of the premises. between them.   10. Method according to claim 1, characterized in that measuring wells (35), (37), visual inspection (36) and safety devices in case of overpressure are arranged on one or more taps (27). ).