EDM DEVICE FOR CARRYING OUT AN EDM PROCESS FOR TAKE MATERIAL SAMPLES FROM METAL COMPONENTS OF NUCLEAR POWER PLANTS, USE OF AN EDM DEVICE, AND METHOD FOR TAKE MATERIAL SAMPLES

Description

[0001] The invention relates to an erosion device for performing an erosion process for taking material samples from metallic components of a wall, preferably the inner wall, of a reactor pressure vessel. Furthermore, the invention relates to the use of an erosion device and a method for taking material samples from metallic components of a wall, preferably the inner wall, of a reactor pressure vessel.

[0002] In nuclear power plants, it may be necessary to take material samples from metallic components of the nuclear power plant, such as the reactor pressure vessel or other core internals, for material testing. This may require relatively large material samples, for example, up to a depth of 100 mm, from the reactor pressure vessel, particularly from the inner wall of the reactor pressure vessel.

[0003] Until now, only boat-shaped (or spherical segment) material samples could be taken using grinding techniques. However, these samples can only be taken up to a depth of 10 mm. This means that these relatively small material samples have had to be sufficient for conducting tests.

[0004] JPH1076427A and JPH07159295A relate to a boat-shaped spark erosion electrode in a sampling device for a structure in a nuclear reactor. In particular, JPH07159295A discloses a fastening element and a collecting and / or trapping device.

[0005] JP2001079658A relates to a sampling device with an electrode. In particular, JP2001079658A discloses a first linear movement of the electrode and then a rotational movement of the electrode during the erosion process to sample a nozzle.

[0006] US5268550A relates to a method and device for removing a sample, in particular a parallelepiped sample, from the inner wall of a nuclear reactor vessel. FR2879949A1 relates to a method for remote machining of a zone of a metal wall of a part, in which an electrode is attached directly to the free end of a robot arm.

[0007] The object of the invention is to provide a new eroding device, in particular an eroding device with which it is possible to produce material samples from metallic

[0008] Components of nuclear power plants, in particular from the wall, preferably the inner wall, of a reactor pressure vessel, whose geometry and size can be freely selected. Furthermore, the object of the invention is to provide a new use of an erosion device and a new method for taking material samples from metallic components of nuclear power plants, in particular from the wall, preferably the inner wall, of a reactor pressure vessel.

[0009] This object is achieved with regard to the erosion device by the features of claim 1, with regard to the use of the erosion device by the features of claim 9 and with regard to the method by the features of claim 10. Advantageous embodiments and further developments are specified in the respective dependent claims.

[0010] The erosion device according to the invention comprises an erosion head, wherein the erosion head has at least one erosion electrode, wherein the erosion electrode has a convex or angular outer shape at least in sections, and wherein the erosion head has a movement control system for positioning and / or moving the erosion electrode, wherein the movement control system comprises at least four axes for carrying out movements of the erosion electrode to produce a predetermined material sample geometry, wherein the movements can also be carried out during the erosion process.

[0011] The movements can be a combination of various linear and rotational movements.

[0012] All movements of the erosion electrode possible with the erosion device according to the invention can be controlled simultaneously, in particular during the erosion process, resulting in a combined movement. A control device is provided which is designed to control the movement or movements individually or simultaneously, preferably remotely.

[0013] The erosion device according to the invention is designed to simultaneously carry out the erosion process and move the erosion electrode.

[0014] It is therefore provided that the erosion electrode is movable with the movement control system on the one hand for positioning the erosion electrode before the erosion process and on the other hand the erosion electrode is movable for generating a predetermined material sample geometry during the erosion process.

[0015] The reactor pressure vessel is the reactor pressure vessel in a nuclear power plant. Spark erosion is the preferred erosion process. Both undercut and step erosion are possible.

[0016] The advantages of the invention lie in the fact that the inventive EDM device can produce material samples of any desired contour and size. The ability to determine the contour and size of the material samples also allows for the removal of defects on or in the surface of metallic components of the nuclear power plant, such as the wall of the reactor pressure vessel. Furthermore, blind hole and through-hole samples are equally possible.

[0017] The mobile, modular design, minimal size, and low weight of the EDM device allow for flexible application possibilities, especially in confined spaces. The EDM device can also be used in water depths of up to 35 meters and more. Furthermore, the EDM device can also be used in high radiation levels.

[0018] A further advantage is that the inventive EDM device ensures high dimensional accuracy. Furthermore, it is easy to handle different material qualities (embrittling, hardening).

[0019] According to a particularly preferred development of the invention, it is provided that the movement control system has at least one first element for carrying out at least three axial movements of the erosion electrode, wherein the three axes are preferably perpendicular to one another.

[0020] At least three of the at least four axes provided for carrying out movements of the erosion electrode are thus provided for carrying out axial movements or linear movements of the erosion electrode.

[0021] According to a preferred embodiment of the invention, it is provided that the first element for carrying out the axial movements comprises at least three carriages, wherein each carriage is movably mounted along one of the axes, so that each carriage enables a movement, in particular an axial movement or linear movement, of the erosion electrode along one of the axes.

[0022] Furthermore, it can be provided that the first element has connecting elements for connecting the carriages to one another, wherein each carriage is connected to an adjacent carriage.

[0023] According to an expedient and advantageous development, the movement control system has at least one second element for carrying out a rotational movement about a rotation axis of the erosion electrode.

[0024] At least one of the at least four axes provided for executing movements of the erosion electrode is thus designed to execute a rotational movement. It can also be provided that the rotational axis is one of the three axes provided for executing axial or linear movements, or coincides with it.

[0025] Particularly preferably, four axes are provided for carrying out movements of the erosion electrode, wherein three of the four axes are perpendicular to one another and are provided for carrying out axial movements or linear movements of the erosion electrode and a fourth axis is provided for carrying out a rotational movement of the erosion electrode, wherein the fourth axis provided as the rotational axis is one of the three axes for carrying out the axial movements or coincides with this.

[0026] This design of the erosion device enables a combination movement or combination movements of the erosion electrode, so that it can be moved in space, preferably as desired, and, in particular, during the erosion process.

[0027] Preferably, the second element comprises a shaft for transmitting the rotational movement to the erosion electrode, wherein the erosion electrode of the erosion head is attached to the shaft.

[0028] For example, the erosion device comprises one or more motors for driving the first element and / or the second element.

[0029] According to a further development of the invention, it can be provided that the erosion electrode is at least partially round, in particular semicircular, or annular, in particular semi-annular, or elliptical, in particular semi-elliptical, or disc-shaped, in particular semi-disc-shaped, at least in sections, preferably in its working area.

[0030] The erosion device has a control device for controlling and / or remotely controlling the erosion head and / or the movement control system and / or the erosion electrode.

[0031] The erosion device comprises a fastening element for attaching the erosion head to metallic components of the wall, preferably the inner wall, of the reactor pressure vessel. Furthermore, the fastening element can comprise one or more suction elements, preferably suction cups.

[0032] The erosion device has a collecting and / or collecting device for collecting and / or collecting the material samples after the erosion process. According to the invention, the use of an erosion device on metallic

[0033] Components of a wall, preferably the inner wall, of a reactor pressure vessel of a nuclear power plant, are provided for carrying out an erosion process for taking material samples from the metallic components of the wall, preferably the inner wall, of the reactor pressure vessel, in particular from the inner wall of the reactor pressure vessel, wherein the erosion device is an erosion device according to the invention. The inventive method for taking material samples from metallic components of the wall of a reactor pressure vessel of a nuclear power plant by means of erosion with an erosion device according to the invention comprises the steps: Guide at least the erosion head to the metallic component, Positioning the erosion head of the erosion device on the metallic component such that the erosion process can be initiated at a predetermined position, Eroding material samples from the metallic component by moving the erosion electrode by means of the movement control system during the erosion process to produce a predetermined material sample geometry, wherein the movement of the erosion electrode by means of the movement control system during the erosion process includes various linear and rotational movements, Collecting and / or catching the material sample, Guide the material sample and / or the erosion head of the erosion device away from the metallic component.

[0034] A further development of the method provides that the erosion device has a movement control system, wherein the movement control system has at least a first element, wherein by means of the first element at least three axial movements of the erosion electrode can be carried out, wherein the three axes are preferably perpendicular to one another.

[0035] A further embodiment of the method provides that the erosion device has a movement control system, wherein the movement control system has at least one second element, wherein a rotational movement about a rotation axis of the erosion electrode can be carried out by means of the second element.

[0036] The movement of the EDM electrode by means of the motion control system during the EDM process can be a combination of various linear and rotational movements.

[0037] All movements of the erosion electrode possible with the erosion device according to the invention can be controlled simultaneously, in particular during the erosion process, resulting in a combined movement. A control device is provided, by means of which the movement or movements can be controlled individually or simultaneously, preferably remotely.

[0038] The erosion process and the movement of the erosion electrode can be carried out simultaneously.

[0039] It is provided that the erosion device has a movement control system, wherein the erosion electrode is moved by means of the movement control system on the one hand to position the erosion electrode before the erosion process to a predetermined position and on the other hand the erosion electrode is moved to produce a predetermined material sample geometry during the erosion process.

[0040] A preferred embodiment of the method according to the invention is defined in claim 11.

[0041] A variant of the method according to the invention provides that the erosion is carried out step by step in several steps.

[0042] The invention will be explained in more detail below with regard to further features and advantages based on the description of an embodiment and with reference to the accompanying drawing. FIG 1 A schematic representation of an embodiment of an erosion device according to the invention. Corresponding parts and components are designated by the same reference numerals in the figures.

[0043] FIG 1shows an erosion device 10 for carrying out an erosion process for taking material samples from the inner wall of a reactor pressure vessel, comprising an erosion head 11. The erosion head 11 has an erosion electrode 12, wherein the erosion electrode 12 has a convex outer shape in sections. Furthermore, the erosion head 11 has a motion control system 13 for positioning and / or moving the erosion electrode 12, wherein the motion control system 13 comprises at least four axes X, Y, Z, R for executing movements of the erosion electrode 12 to produce a predetermined material sample geometry 21, wherein the movement or movements can also be carried out during the erosion process.

[0044] The movement control system 13 has a first element 14 for carrying out three axial movements of the erosion electrode 12, wherein the three axes X, Y, Z are perpendicular to each other.

[0045] The first element 14 comprises at least three carriages 15a, 15b, 15c for carrying out the axial movements, wherein each carriage 15a, 15b, 15c is movably mounted along one of the axes X, Y, Z, so that each carriage 15a; 15b; 15c enables a movement of the erosion electrode 12 along one of the axes X, Y, Z.

[0046] The first element 14 also has connecting elements 16 for connecting the carriages 15a; 15b; 15c to one another, wherein each carriage 15a, 15b, 15c is connected to an adjacent carriage 15a, 15b, 15c.

[0047] The motion control system 13 has a second element 17 for performing a rotational movement about a rotation axis R of the erosion electrode 12. The second element 17 further comprises a shaft 18 for transmitting a rotational movement to the erosion electrode 12, wherein the erosion electrode 12 of the erosion head 11 is attached to the shaft 18.

[0048] The erosion electrode 12 is partially round, in particular semi-circular, in its working area 19.

[0049] The erosion device 10 also has a control device (not shown in the figure) for controlling and / or remotely controlling the erosion head 11, the movement control system 13 and the erosion electrode 12.

[0050] The erosion device 10 further comprises a fastening element 20 for attaching the erosion head 11 to a wall of the reactor pressure vessel. The fastening element 20 comprises a plurality of suction elements designed as suction cups.

[0051] The erosion device 10 further comprises a collecting and / or collecting device (not shown in the figure) for collecting and / or collecting the material samples after the erosion process.

[0052] According to the invention, the erosion device 10 is used to carry out an erosion process for taking material samples from the inner wall of a reactor pressure vessel.

[0053] With the erosion device 10 according to the invention, a method for taking material samples from the inner wall of a reactor pressure vessel by means of erosion can be carried out, which comprises the steps: Inserting at least the erosion head 11 of the erosion device 10 into the reactor pressure vessel, positioning the erosion head 11 of the erosion device 10 in the reactor pressure vessel such that the erosion process can be initiated at a predetermined position, eroding material samples from the wall of the reactor pressure vessel by moving the erosion electrode 12 by means of the movement control system 13 during the erosion process to produce a predetermined material sample geometry 21, collecting and / or catching the material sample, removing the material sample and / or the erosion head 11 of the erosion device 10 from the reactor pressure vessel.

[0054] The erosion device 10 has a fastening element 20 for fastening the erosion head 11 to the inner wall of a reactor pressure vessel, and the erosion head 11 is fastened to the inner wall of the reactor pressure vessel by means of the fastening element 20 after it has been inserted into the reactor pressure vessel.

[0055] For example, erosion can be carried out gradually in several steps. List of reference symbols

[0056] 10 EDM device 11 EDM head 12 EDM electrode 13 Positioning and / or motion control system 14 First element 15a Slide 15b Slide 15c Slide 16 Connecting element 17 Second element 18 Shaft 19 Working area 20 Fastening element 21 Material sample geometry Xaxis Yaxis Zaxis RRotation axis

Claims

1. Eroding device (10) for carrying out an eroding process for taking material samples from metallic components of a wall, preferably the inner wall, of a reactor pressure vessel of nuclear power plants, comprising an eroding head (11) and a fastening element (20) for fastening the eroding head (11) to metallic components of the wall, preferably the inner wall, of the reactor pressure vessel, the eroding head (11) having an eroding electrode (12), the eroding electrode (12) having, at least in sections, a convex or angular outer shape, and wherein the eroding head (11) has a motion control system (13) for moving the eroding electrode (12), wherein the eroding electrode (12) is movable with the motion control system (13), on the one hand, for positioning the eroding electrode (12) ) on the metallic component before the eroding process, in such a way that the eroding process can be initiated at a designated position, and the eroding electrode (12) can also be moved during the eroding process in order to produce a designated material sample geometry, the motion control system (13) comprises at least four axes (X; Y; Z; R) for executing a combination of different linear and rotational movements of the eroding electrode (12) during the eroding process to produce a desired material sample geometry (21), and wherein the eroding device (10) comprises a control device which is designed to control the motion control system (13) for executing the various linear and rotational movements of the eroding electrode (12) individually or simultaneously during the eroding process for producing a planned material sample geometry (21), wherein the eroding device (10) comprises a collecting and / or catching device for collecting and / or catching the material samples after the eroding process.

2. An eroding device according to claim 1, characterised in that the motion control system (13) has at least one first element (14) for carrying out at least three axial movements of the eroding electrode (12), the three axes (X; Y; Z) preferably being perpendicular to one another.

3. An eroding device according to claim 2, characterised in that the first element (14) comprises at least three carriages (15a; 15b; 15c) for carrying out the axial movements, each carriage (15a; 15b; 15c) being mounted movably along one of the axes (X; Y; Z), so that one carriage (15a; 15b; 15c) in each case enables a movement of the eroding electrode (12) along one of the axes (X; Y; Z).

4. An eroding device according to claim 3, characterised in that the first element (14) has connecting elements (16) for connecting the carriages (15a; 15b; 15c) to one another, each carriage (15a; 15b; 15c) being connected to an adjacent carriage (15a; 15b; 15c).

5. An eroding device according to one of the preceding claims, characterised in that the motion control system (13) has at least one second element (17) for carrying out a rotational movement about an axis of rotation (R) of the eroding electrode (12).

6. An eroding device according to claim 5, characterised in that the second element (17) has a shaft (18) for transmitting the rotational movement to the eroding electrode (12), the eroding electrode (12) of the eroding head (11) being attached to the shaft (18).

7. An eroding device according to one of the preceding claims, characterised in that the eroding electrode (12) is at least partially round or annular or elliptical or disc-shaped, at least in sections.

8. An eroding device according to one of the preceding claims, characterised in that the fastening element (20) comprises one or more suction elements.

9. Use of an eroding device (10) on metallic components of a wall, preferably the inner wall, of a reactor pressure vessel of a nuclear power plant, for carrying out an eroding process for the removal of material from metallic components of the wall, preferably the inner wall, of the reactor pressure vessel, the eroding device (10) being an eroding device (10) according to one of the preceding claims.

10. A method for removing material samples from metallic components of a wall of a reactor pressure vessel of nuclear power plants, by means of eroding with an eroding device (10) according to one of the preceding claims, comprising the steps: - Moving at least the eroding head (11) towards the metallic component, - Positioning the eroding head (11) of the eroding device (10) on the metallic component in such a way that the eroding process can be initiated at a designated position, - Eroding of material samples from the metallic component by moving the eroding electrode (12) by means of the motion control system (13) during the eroding process to produce a planned material sample geometry (21), wherein the movement of the eroding electrode (12) by means of the motion control system during the eroding process includes various linear and rotational movements, - Collecting and / or catching the material sample, - Moving the material sample and / or the eroding head (11) of the eroding device (10) away from the metallic component.

11. A method according to claim 10, characterised in that the wall is an inner wall, in that the guiding of at least the eroding head (11) to the metallic component comprises the introduction of at least the eroding head (11) of the eroding device (10) into the reactor pressure vessel, that the eroding head (11), after its insertion into the reactor pressure vessel, is attached to the inner wall of the reactor pressure vessel by means of the fastening element (20), wherein positioning the eroding head (11) of the eroding device (10) on the metallic component comprises positioning the eroding head (11) of the eroding device in the reactor pressure vessel, and wherein the removal of the material sample and / or the eroding head (11) of the eroding device (10) from the metallic component comprises the removal of the material sample and / or the eroding head (11) of the eroding device (10) from the reactor pressure vessel.

12. A method according to claim 10 or 11, characterised in that the eroding is carried out in stages in several steps.