GB1594839A

GB1594839A - Installation for packing radioactive waste material in drums

Info

Publication number: GB1594839A
Application number: GB5409077A
Authority: GB
Original assignee: Kernforschungszentrum Karlsruhe GmbH
Current assignee: Forschungszentrum Karlsruhe GmbH
Priority date: 1976-12-31
Filing date: 1977-12-29
Publication date: 1981-08-05
Also published as: CH627582A5; DE2659691C2; DE2659691A1

Abstract

The system consists of a compression press operating partly in an alpha-particle-tight compression box (3) and is intended for carrying out all the operations required for compression in a single compact system. The press contains at least two tie rods (23) to the upper ends of which there is attached a compression cylinder (25) having a plunger (55) acting downwards, and between the lower ends of which there is attached thereto a compression table (24) which receives the waste drum (22), it being possible for the plunger (55) to be moved into the drum (22). The drum (22) can be raised with the compression table (24) by means of lifting devices, and can be pressed against the loading openings (32) in the floor (21) of the compression box (3). Provided between the tie rods (23) is a hollow injection cylinder (17) which can be moved into the drum (22) into whose interior (36) the plunger (55) can be moved. When the injection cylinder (17) is moved high, concrete is pressed into the annular space produced. The advantage of the system is that the waste is intimately connected to the concrete jacket and that the concrete jacket is produced simultaneously with the compression operation. <IMAGE>

Description

(54) AN INSTALLATION FOR PACKING RADIOACTIVE WASTE IN DRUMS (71) We, KERNFORSCHUNGSZENTRUM KARLSRUHE GESSELSCHAFT MIT BESCHRA ENKTER HAFTUNG, formerly Gessellschaft far Kernforschung m.b.H., of 5 Weber sfrasse, D-7500 Karlsruhe 1, Federal Republic of Germany, a German body corporate, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- The present invention relates to an installation for packing radioactive waste material in drums, with or without concreting of the packed waste, comprising a packing or tamping press operating at least partly within a box capable of handling apha-emitters.

A large proportion of radioactive waste materials accruing in nuclear plants may be compacted. This substantially concerns contamination waste materials, filter material, small scrap particles, sheet metal particles, isolating material and the like. For smaller nuclear plants it is not worthwhile erecting an incinerating plant for combustible radioactive waste materials having a large input factor. For this reason, in small nuclear plants, e.g. in individual nuclear power stations, the radioactive waste is compacted.

In order to secure the radioactive wastes in the waste container it is generally advised, from a certain activity stage on, to enclose these waste materials within a concrete layer.

At the same time, however, a proportion of the radioactive waste materials, which for geometrical reasons cannot be directly charged into a waste container, has to be precrushed.

Packing plants are already known in which drums are provided with a preconcreted internal jacket, or in which the radioactive waste materials are first pressed in a press cylinder into tablets which are then ejected into a waste drum, whereby the remaining space can be filled up with liquid concrete. Such plants among other things have the disadvantage that besides the actual comminuting and charging box, a very complex and costly press has to be used. The drums to be packed either have first to be lined with concrete or, for pressing the waste materials, a separate container has to be used so as to prevent the radioactive material from swelling after pressing. The known plants, moreover, have the disadvantage that they cover several storeys and occupy considerable space.Moreover, said pre-concreted drums have subsequently to be fitted with a concrete seal above the contents thereof and therefore, after uncoupling from the plant the drums cannot finally be sealed by a cover until after fitting of the concrete seal.

The present invention has as an object a single compact plant for carrying out all operations necessary for compacting, from which a finally storable product is obtained as the end product.

According to the present invention there is provided an installation for packing radioactive waste material in drums, with or without concreting of the packed waste, comprising a packing press operating at least partly within a box capable of handling alpha emitters in which the press consists of at least two tie bars, on the upper ends of which a press cylinder with a downwardly acting pressing ram is secured and between the lower ends of which a waste drum is placed, the pressing ram being insertable into the drum.

Of particular advantage in accordance with the proposed invention is that the drum is adapted to be lifted by means of lifting devices together with the press table and to be pressed against a charging aperture in the base of the press box, whereby preferably the lifting devices are comprised of pressure cylinders located at the lower ends of the tie bars and the connecting rods of which acting axially in extension of the tie rods being hingedly connected to the press table. Preferably, however, the press cylinder is anchored in the upper part of the press box and projects at least with its lower end into the box. In this manner a secure anchoring of the installation within the building is not necessary and the drum in which the waste materials are directly compressed may be caused, in the simplest manner, to assume a position beneath the press or to be connected to the press box.The invention moreover proposes to allow the lifting devices to act directly between the base of the press box and the press table, whereby mechanical lifting gears are provided. This permits the drum to be pressed directly against the base of the press box without any hydraulic pressure cylinders being located in the tie bars.

To attain the object described above the present invention moreover proposes that between the tie bars there is provided a hollow cylinder with an upper flange. insertable in the drum through the aperture and in the interior space of which the ram acts, where by the tipper flange of the hollow cylinder expediently slides along the tie bars and is adapted by means of lifting cylinders to be lifted out of the drum, and said lifting cylinders being fixed on the press cylinder.

Of particular advantage in accordance with the proposed invention is that the hollow cylinder is provided with at least one axially extending connecting passage between its two end faces, to which a concrete storage container is connected and that, at the lower end of the interior space in the hollow cylinder, a base plate is adapted to be clamped by means of springs. The present invention further proposes that between the upper edge of the drum and the base of the press box, an annular grease chamber is provided by means of which a coating of grease may be applied to the outer wall surface of the hollow cylinder.

The particular advantage of the charging installation in accordance with the invention consists in that the waste materials are intimately connected with the concrete jacket, and that the concrete jacket is produced substantially simultaneously with the packing operation. By inserting the base plate, a reinforcement of the drum is obtained. The hollow cylinder remains substantially free from caking by coating with the layer of grease. Connection and disconnection of drums with radioactive waste materials may hence be effected substantially without contamination. The radioactive waste materials may be accurately secured about the centre axis of the drum, so that the concrete jacket enclosing them constitutes a uniformly thick and effective protection.

Finally, during compacting of filters or bulky material, no manual operation is required in the box, since they are adapted to be inserted from outside the box into the drum.

The present invention will be further illustrated. by way of example, with reference to the accompanying drawings, in which: Fig. I is a cross-section through an instal lition in accordance with the invention Fig. 2 is a side view of the actual press device without the press box; and Fig. 3 is a detail of the ringed portion C of Fig. 1.

As shown in Fig. I, the installation is comprised of a three-part combination formed by the supply box 1 with drum connection. the filter charging and comminuting box 2, and the press box 3. By boxes there are understood so-called glove working boxes under vacuum, which in the usual manner are provided with sealed windows 5 and rubber glove sleeves 6 for manipulation.

Radioactive waste materials, which are generally supplied in 200 litre iron-hooped drums are changed into the supply box I by means of a tipping device, not shown, and a charging aperture 4 provided with a double cover. In this box I, waste materials which are unsuitable for packing can either be sorted out or pre-treated. Box I moreover is provided with a circular saw 8 located on a hingable table 7 and lowerable by means of pedal 9, in order to allow the pre-comminuting of wood or other bulky components.

Furthermore, the installation comprises a filter charging and comminuting box 2. The filters 10 are charged into the box 2 via a charging valve, not shown, which is provided with a diagonally located flap. During transportation and charging, the filters 10 are additionally provided with a sheet-like packing. A shredder 11 for comminuting bulky waste materials, is provided in the filter charge box 2. By means of the shredder 11, the drive 12 of which is located outside the box 2, the filters 10 or other bulky comminutable waste materials are shredded. To obtain a satisfactory engagement of the filters 10 or other bulky materials by the shredder 11, a compressed air cylinder 13 with a pressure plate 14 on its piston 15 is located above the shredder 11, which piston presses the filter 10 against the shredder 11 and thereby produces a forward feed in the direction of the shredder 11.A table base 16 is mounted below the shredder 11 which is level with the surface 18 of a cylinder 17 in the press box 3.

On this table base 16 there is a slider 19 which, by means of a pushrod 20, pushes the comminuted waste materials 52 into the press box 3.

The main portion of the installation is located in the press box 3, viz. the actual press and filling or charging device for the iron-hooped drum 22 connected to the base 21 of the box 3. The pressing device, which is separately shown in Fig. 2, consists substantially of two or more uprights or tie bars 23 which interconnect the press table 24 and the press cylinder 25. The tie bars 23 are thus passed sealed through the base 21 and the cover 26 of the press box 3, so that they are unable to exert any pressing forces thereon.

The press cylinder 25 is securely connected at the top end to the tie bars 23 and frictionally inserted in the box cover 26. On the lower end of the tie bars 23, the press table 24 is secured in a special manner so that it can be slightly raised relative to the base 27. For this purpose in the lower end of each tie bar 23 a pressure cylinder 28 is provided, the piston 29 of which acting upwards is connected hingedly to the press table 24 by means of a piston rod 30. On the press table 24, the upper surface of which is adapted to the base of the drum, the iron-hooped drum 22 is placed and pressed by means of the pressure cylinder 28 with its upper edge 31 against the aperture 32 in the base 21 of the box 3, so as to abut in a hermetically sealed manner. The matching press table ensures a satisfactory power transmission.It is also possible to dispense with the pressure cylinders 28 and to press the drum 22 directly from the base 27 against the edge of the aperture, whereby preferably mechanical lifting gears with spindle drive may be used. By said lifting gears, the pressure application force is produced which is necessary for the sealing off of the drums and which should be somewhat stronger than the compacting force of the ram 55. Between the drum 22 and the base 21, a slider 33 is mounted by means of which the aperture 32 may be closed when no drum is connected. A grease chamber 34, with a radially inwardly acting grease discharge, is inserted between the edge 31 of the drum and the slider 33, by means of which the outer surface of the cylinder 17 insertable into the drum 22 may be provided with a layer of grease.

The said cylinder 17 is a hollow body made of steel, the cylindrical part of which is insertable in the drum 22 and the upper flange 35 of which slides or is guided along the guide uprights or tie bars 23. The interior space 36 of the cylinder 17 opens at the top with an aperture 37 through which the drum 22 may be charged from the interior space of the box 3. At the lower end of the cylinder 17, a base plate 39 is clamped by means of springs 38 in the interior space 36, which plate after charging remains in the drum 22.

One or more passages 40 are formed in the wall of the cylinder 17 and extend axially to the cylinder, the middle-lines 41 of which are shown as chain-dotted lines in Fig. I and which in Fig. 3 are shown exactly. The passages are open towards the bottom in the cylinder 22 and connected towards the top with the socket 42 to the supply conduit 43 of a concrete plant 44. The concrete plant 44 consists of the storage container 45, which by means of a compressed air line 46 is maintained under pressure, the discharge valve 47 incorporated in the supply conduit 43, and the concrete forward pass 48 and concrete return pass 49. By means of this concreting device 44, via the conduit 43 and the passage 40, concrete can now be charged below the cylinder 17 into the drum 22. The cylinder 17 is displaceable independently of the table 24 as evident from Fig. 2, i.e. it may be lowered and raised.For this purpose it is suspended on the piston rods 50 which are actuated by the lifting cylinders 51, whereby these lifting cylinders 51 in turn are secured to the press cylinder 25. The cylinder 17 is relatively heavy and is drawn downwards by its dead weight. The press cylinder 25, which is securely anchored in the upper part 26 of the box 3, is fitted with a double-acting piston 53 of which piston rod 54 below the pressing ram 55 is located protruding from the cylinder 25. This pressing ram 55 acts downwards and is insertable into the interior space 36 of the cylinder 17 in order to compact or compress the waste materials 56 charged therein before the ram actuation.

The press piston 55 during the filling of the cylinder 17 is at its upper dead centre and, as already mentioned, may be extended for pressing the waste materials 56 or 52 to the base of the cylinder 17 or the waste drum 22.

During the fixing of the drum 22, the cylinder 17 is located within the press box 3, i.e. in its upper dead centre position. After coupling the drum 22 to the aperture 32 by means of the cylinder 28 the cylinder 17 is inserted by means of the lifting device 50, 51 into the drum 22. During this the outer surface of the cylinder 17 slides over the grease chamber 34 located above the drum seal. The grease chamber 34 is subjected to a slight excess pressure, or during the insertion by means of a grease press, a certain quantity of grease is forced into the grease chamber 34, so that the outer surface of the cylinder 17 during insertion is provided with a thin layer of grease. After the cylinder 17 has reached the lower dead centre position, the interior space 36 of the cylinder 17 may be filled either from box 1 or box 2 with radioactive waste materials 56 or 52.After filling the cylinder 17 to the upper edge, the contents are compressed by means of the pressing ram 55. The pressing power of the cylinder 25 is lower than that of the cylinder 28, since otherwise the drum 22 would no longer be pressed against the base 21. The cylinder 17 may now be further filled up to a filling mark. The pressing ram 55 now stops against the materials pressed. Then the cylinder 17, by means of the lifting device 50, 51, is drawn upwards. At the same time from the concrete storage container 45, which is provided with a cushion of compressed air, liquid concrete is forced via the conduit 43 and the passage 40 into the annular space created during the upwards movement of the cylinder 17. This at the same time prevents the material 56, within the cylinder 17, from swelling.The base plate 39 inserted prior thereto, since the pressing ram 55 abuts against the material 56, remains on the drum 22 and hence causes a reinforcement of the bottom of the drum.

Aftcr the cylinder 17 has been raised to such an extent that its lower edge is on the same level as the pressing ram 55, both are lifted off together and at the same time the concrete charge continued. so that an upper layer of concrete is formed on the packed waste.

In order to obtain a constant charging state in the storage container 45. concrete is pumped in circulation. The return flow 49 is located as overflow so that in the container 45 a constant state of filling prevails. The prior applied grease lilm on the cylinder 17 prevents the cement mixture from reaching between the outer wall of the cylinder 17 and the inner wall of the waste drum 22 and there to become caked against the outer wall of the cylinder 17 On rc;lching the upper dead centre position both of the pressing ram 55 and the cylinder 17, the waste drum 22 is removed from the base 21 of the box 3 and immediately sealed by coating the waste materials in the drum 22 during removal from the base 21 with a layer of inactive concrete.After the removal from the base 21, a new base plate 39 is immediately inserted into the cylinder 17 instead of the one remaining in the drum so that this aperture is substantially hermetically sealed.

Concreting in the lining, in containers with more strongly radioactive waste however, has the advantage that the cement grout bonds intimately with the compressed waste, i.e.

seeps into any possible cracks and fissures which remain open during pressing and hence a substantially solid block is produced.

WHAT WE CLAIM IS: I. An installation for packing radioactive waste material in drums, with or without concreting of the packed waste, comprising a packing press operating at least partly within a box capable of handling alpha emitters in which the press consists of at least two tie bars, on the upper ends of which a press cylinder with a downwardly acting pressing ram is secured and between the lower ends of which, a press table is secured thereto on which a waste drum is placed, the pressing ram being insertable into the drum.

2. An installation as claimed in claim 1, in which the upper surface of the press table has an outline adapted to the base of the drum.

3. An installation as claimed in claim 2, in which the drum, by means of lifting devices, is raisable together with the press table to be pressed against a charging aperture in the base of the press box.

4. An installation as claimed in claim 3, in which the lifting devices comprise pressure cylinders located along the tie bars at the lower ends thereof, and the connecting rods of which are hingedly connected to the press table acting axially in extension of the tie bars.

5. An installation as claimed in claim 3, in which the lifting devices for the press table act directly between the base of the press box and the press table.

6. An installation as claimed in claim 5, in which the lifting devices comprise mechanical lifting tackles.

7. An installation as claimed in any preceding claim, in which the press cylinder is anchored in the upper part of the press box and, at least with its lower end, projects into the box.

8. An installation as claimed in any one of claims 3 to 6, or claim 7 when dependent on any one of claims 3 to 6. in which a hollow cylinder with an upper flange insertable in the drum through the aperture, is provided between the tie bars in the interior space of which the ram acts.

9. An installation as claimed in claim 8, in which said upper flange of the hollow cylinder slides along the tie bars and by means of lifting cylinders is liftable out of the drum and said lifting cylinders are fixed on the press cylinder.

10. An installation as claimed in claim 8 or 9, in which the hollow cylinder has at least one axially extending communicating passage between its two end faces, to which a concrete storage container is connected.

I 1. An installation as claimed in claim 8, 9 or 10, in which at the lower end of the interior space in the hollow cylinder, a base plate, securable by springs, is adapted to be clamped.

12. An installation as claimed in claim 8, 9, 10 or I I, in which an annular grease chamber is provided between the upper edge of the drum and the base of the press box, by means of which a layer of grease may be applied radially inwardly to the outer wall surface of the hollow cylinder.

13. An installation for packing radioactive waste material in drums, with or without concreting of the packed waste, substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **.

an extent that its lower edge is on the same level as the pressing ram 55, both are lifted off together and at the same time the concrete charge continued. so that an upper layer of concrete is formed on the packed waste.

In order to obtain a constant charging state in the storage container 45. concrete is pumped in circulation. The return flow 49 is located as overflow so that in the container 45 a constant state of filling prevails. The prior applied grease lilm on the cylinder 17 prevents the cement mixture from reaching between the outer wall of the cylinder 17 and the inner wall of the waste drum 22 and there to become caked against the outer wall of the cylinder 17 On rc;lching the upper dead centre position both of the pressing ram 55 and the cylinder 17, the waste drum 22 is removed from the base 21 of the box 3 and immediately sealed by coating the waste materials in the drum 22 during removal from the base 21 with a layer of inactive concrete.After the removal from the base 21, a new base plate 39 is immediately inserted into the cylinder 17 instead of the one remaining in the drum so that this aperture is substantially hermetically sealed.

Concreting in the lining, in containers with more strongly radioactive waste however, has the advantage that the cement grout bonds intimately with the compressed waste, i.e.

seeps into any possible cracks and fissures which remain open during pressing and hence a substantially solid block is produced.

WHAT WE CLAIM IS: I. An installation for packing radioactive waste material in drums, with or without concreting of the packed waste, comprising a packing press operating at least partly within a box capable of handling alpha emitters in which the press consists of at least two tie bars, on the upper ends of which a press cylinder with a downwardly acting pressing ram is secured and between the lower ends of which, a press table is secured thereto on which a waste drum is placed, the pressing ram being insertable into the drum.
2. An installation as claimed in claim 1, in which the upper surface of the press table has an outline adapted to the base of the drum.
3. An installation as claimed in claim 2, in which the drum, by means of lifting devices, is raisable together with the press table to be pressed against a charging aperture in the base of the press box.
4. An installation as claimed in claim 3, in which the lifting devices comprise pressure cylinders located along the tie bars at the lower ends thereof, and the connecting rods of which are hingedly connected to the press table acting axially in extension of the tie bars.
5. An installation as claimed in claim 3, in which the lifting devices for the press table act directly between the base of the press box and the press table.
6. An installation as claimed in claim 5, in which the lifting devices comprise mechanical lifting tackles.
7. An installation as claimed in any preceding claim, in which the press cylinder is anchored in the upper part of the press box and, at least with its lower end, projects into the box.
8. An installation as claimed in any one of claims 3 to 6, or claim 7 when dependent on any one of claims 3 to 6. in which a hollow cylinder with an upper flange insertable in the drum through the aperture, is provided between the tie bars in the interior space of which the ram acts.
9. An installation as claimed in claim 8, in which said upper flange of the hollow cylinder slides along the tie bars and by means of lifting cylinders is liftable out of the drum and said lifting cylinders are fixed on the press cylinder.
10. An installation as claimed in claim 8 or 9, in which the hollow cylinder has at least one axially extending communicating passage between its two end faces, to which a concrete storage container is connected.
I 1. An installation as claimed in claim 8, 9 or 10, in which at the lower end of the interior space in the hollow cylinder, a base plate, securable by springs, is adapted to be clamped.
12. An installation as claimed in claim 8, 9, 10 or I I, in which an annular grease chamber is provided between the upper edge of the drum and the base of the press box, by means of which a layer of grease may be applied radially inwardly to the outer wall surface of the hollow cylinder.
13. An installation for packing radioactive waste material in drums, with or without concreting of the packed waste, substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.