RO127982B1 - Sampling tool having a purge system - Google Patents

Abstract

A sampling tool for obtaining a sample from an interior wall of a tube comprises first and second cutter sub-assemblies operatively connected to a shaft. First and second actuators move the first and second cutter sub-assemblies between a retracted position and an extended position as the shaft moves. A valve selectively fluidly communicating an ejection port located in one of the first and second cutter sub-assemblies with a purge fluid supply. The valve discharges purge fluid through the ejection port onto the interior wall of the tube during cutting of a portion of the wall.

Description

The invention relates to a circular tool for taking samples from the pressure tubes of nuclear reactors, such as those of the CANDU type.

A tool for sampling, used in pressure tubes, known in Inovation in pressure tube rolled joint sampling, Guler B, King JM, Wray R, Seventh annual international conference on CANDU maintenace, 20 - 22.11.2005, Toronto, showing that two knives are required to obtain a sample of material from a pressure tube, one knife to remove the oxide layer, and the second knife to cut the material sample, water the heavy being removed either by the use of a covering gas or with mild water, to prevent deuterium from entering the cavity remaining after sampling; the multiple cutting tool uses four sets of cutting heads; In order to facilitate the sampling of several material samples in a single operation, the cutting knives are circumferential, so that the prototype contains four main modules, which consist of a locking tool and a connection module, a tool head module, a tool module. control and a connector module; the knives for the oxide layer and the material sample are provided in separate cartridges, in cartridge cases; cartridge cases pass over a ramp, lifting knives, to cut oxide and material sample; the oxide and the sample material are kept in small cavities provided in the tool; the light water that purges the heavy water is controlled by valves, one for each knife.

Also known is a tool for sampling, used in pressure tubes, presented in Advanced pressure tube sampling tube Canadian nuclear society bulletin, vol. November 23, 2000, Wittch KC, King JM, (D2), showing how the multiple head for material sampling is capable of taking four-spot samples in a single operation, the cartridge boxes containing four sets of knives , being provided with a flexible connection, to allow bending of the pressure tube; there is also exposed a new procedure for sampling material, in which the box moves forward and then backward, to self-position, also showing that the ramp mechanism must be locked in place, so that the movement the cassette can be made electrically or hydraulically, being able to provide a measurement of the necessary driving force, being used a light water current, which is directed to the cutting head, with the help of valves.

Also known is a tool for taking samples, used in pressure tubes, disclosed in US Pat. No. 4925621, which has a device for taking a sample of material from the inside of a pressure tube of nuclear reactors, which has a tool for removal of the oxide layer, and a tool for cutting the sample, the knives being moved to the cutting place by means of a ramp or cam mechanism, a groove or vessel for the ox and sample being provided, the mechanism carrying out the longitudinal sampling, not a circumferential sampling.

Also known is a tool for sampling, used in pressure tubes, disclosed in US patent 6599067 B2, which refers to a device for replacing pressure tubes, which has a drill tool, which can be moved longitudinally. , extended radially and moved radially along the longitudinal axis, not describing the mechanism of tool extension to a certain depth, nor does it reveal how the oxide start and sample are removed from the same space.

The circular tool for sampling, according to the invention, has a purge valve that selectively communicates the fluid from the outlet to the purge fluid reservoir, the purge valve being fixed to one of the first milling subassembly and the second milling subassembly, so that the purge valve moves with at least one of the first milling subassembly and the second milling subassembly having an outlet; purge valve

EN 127982 Β1 allows the fluid from the outlet to be communicated with the purging fluid reservoir, when 1 at least one of the first milling subassembly and the second milling subassembly having an outlet is in the extended position, following the discharge of the purging fluid. through the discharge port 3, on the inner wall of the tube, during the cutting through the corresponding mill, one of the first and second mills; the purging fluid is discharged into one of the areas which correspond to the first or second milling machine.

The objective technical problem solved by the invention consists in the in situ testing of the pressure tubes of the nuclear reactors, without the need for the previous isolation and drying of the pressure tube. 9

A method of evaluating the life of pressure tubes in nuclear reactors, such as a CANDU reactor, requires periodic removal of a tube. The samples are cut 11 from the distant tube and analyzed from the point of view of the deuterium content. The deuterium concentration is then used as a measure of the lifetime of the remaining 13 pressure tubes. This approach is very costly due to the long downtime required to remove and replace a pressure tube. 15 The attempt to perform the sampling in situ, without removing the pressure tube, presents many difficulties. Obtaining a useful sample is made difficult due to the 17 hard oxidized surface and the need to obtain the sample material under the surface layer.

In order to maintain the structural integrity of the tube, and to avoid harmful residual stress, the sampling depth must be controlled, and the sample region must be unchanged in geometry on all axes. Furthermore, the technique used to remove surface material 21 or the sample should not involve excessive heating, as this affects the results of subsequent analysis. Another difficulty is to recover sample 23 for analysis, and to protect against the remaining particles in the pressure tube.

It is an object of the present invention to provide a sampling tool, which allows in situ testing without the need for previous isolation and drying of the pressure tube.

The sampling tool has at least two mills that move along a portion of an inner wall of the tube. One mill eliminates part of the inner wall of the tube, and the second mill removes a sample from the inner wall of the tube, from a location in tube 29 highlighted by removing the portion from the inner wall of the tube. The sampling tool contains drainage holes for the purged fluid to discharge the purged fluid during cutting at least a portion of the inner wall of the sample. Discharging the purge fluid removes at least partially the heavy water at the cutting locations. In one aspect, the invention provides a sampling tool for obtaining a sample from an inner wall of a tube. The sampling tool contains a cylindrical body 35 with a central axis, an opening in the cylindrical body. A shaft is disposed in the cylindrical body along the central axis. The tree is mobile. A milling subassembly is functionally connected to 37 shafts.

The first milling subassembly has a first milling cutter. The first milling subassembly moves 39 between a retraction position, in which the first milling is disposed inside the cylindrical body, at a first distance from the central axis, and an extension position in which the first milling is extended at least in part, by opening , at a second distance from the central axis. The second distance is greater than the first distance. A first milling subassembly moves from the extension position, in 43 in which the shaft moves from the first position, which causes the cutter to cut a portion of the inner wall of the tube. The second milling subassembly is operatively connected to the shaft. The second 45 milling machine assembly has the second milling machine.

RO 127982 Β1

The second mill subassembly moves radially between a retraction position, where the second mill is disposed inside the cylindrical body, at a third distance from the central axis, and an extension position, where the second mill extends at least in part, through opening, at a fourth distance from the central axis. The fourth distance is greater than the third distance. A second milling subset moves between the retraction position, where the shaft moves to the second position, which causes the second mill to cut the sample from the inner wall of the tube from a location revealed by cutting the portion from the inner wall. of the tube with a first milling cutter.

A first actuator is operatively connected to a first milling subassembly, for moving the first milling subassembly between a retraction position and the extension position, for the shaft to move to the first position.

A second actuator is operatively connected to a second milling subassembly, for moving the first milling subassembly between a retraction position and the extension position, for the shaft to move to the second position. At least one of the first milling subassembly and the second milling subassembly has an outlet. A purge valve connects the purge port with a supply of purge fluid. The purge valve is fixed to one of the first milling subassembly and the second milling subassembly, so that the purging valve displaces at least the first milling subassembly or the second milling subassembly, which has an outlet. The bleed valve allows the fluid from the outlet to be communicated with the reserve for the bleed fluid, when at least one of the first milling subassembly and the second milling drill with the outlet is in the extended position, following the discharge of the bleeding fluid through the discharge hole on the wall inside of the tube, during the cutting by the corresponding mill, one of the first or second milling cutter. The purging fluid is discharged into one of the areas corresponding to the first or second milling machine.

In another aspect of the invention, the outlet is a first outlet, and the first milling subassembly has the first outlet. The second milling subassembly has a second outlet.

In a further aspect of the invention, the purge valve allows selective communication of the fluid from the first outlet and the second outlet with the reserve of purge fluid. The purge valve allows the fluid to be communicated between the first outlet orifice with the purge fluid reservoir, when the shaft moves from a first position, and the purge valve allows the fluid to be communicated between a second outlet orifice with the purge fluid reservoir, then when the shaft moves to a second position.

In another aspect of the invention, the purge valve is a first purge valve fixed to the first milling subassembly. The first purge valve allows selective communication of the fluid from the discharge port with the purge fluid reservoir. A second purge valve is attached to the second milling subassembly.

The second purge valve allows selective communication from the second discharge port with the purge fluid reservoir. The first purge valve allows communication from the first purge port with the purge reservoir when the shaft moves to the first position, and the second purge valve allows the fluid to communicate with the second purge port with the purged fluid, when the shaft moves to the second position.

In a further aspect of the invention, the purge valve is axially located between the first milling subassembly and the second milling subassembly.

In a further aspect of the invention, when the first purge valve allows 1 fluid communication from the first discharge port to the purge fluid reservoir, the second purge valve provides fluid communication between the second outlet and the reservoir. 3 to the purge fluid, and when the second purge valve communicates between the second outlet and the purge fluid reservoir, the first purge valve prevents fluid 5 from being communicated between the first purge port and the purge fluid reservoir.

In a further aspect, the shaft can rotate, and the first and second positions of the shaft 7 are angular positions.

In another embodiment, the purge valve is an electromagnetic valve. 9 In a further aspect, the first milling subassembly is located on the opposite side of the second milling subassembly. In a further aspect of the invention, the shaft is axially displaceable, and the first and second positions of the shaft are longitudinal positions of the shaft relative to the cylindrical body. 13 In another aspect, the purge valve is a vent valve.

In another aspect of the invention, the first milling subassembly is located towards the second subassembly 15, relative to a direction of cutting of the first mill and the second mill.

In a further aspect, the outlet is a first outlet and at least one of the first milling subassembly and the second milling subassembly has the first outlet and also the second outlet. 19 In another aspect, the first outlet hole is located toward one corresponding to the first mill and the second mill, relative to a direction of cutting of the first mill and the second mill. The second outlet hole exceeds by the corresponding one of the first mill and the second mill. In a further aspect of the invention, the outlet hole extends through the corresponding mill, the first mill and the second mill. In another aspect of the invention, the outlet hole is located toward the one corresponding to one of the first mill and the second mill, relative to a cutting direction thereof. In a further aspect of the invention, the retraction ramp has a first portion and a second ramp portion. The first portion of the ramp is larger than the second portion of 29 ramps. The second roller runs over the second ramp portion of the retraction ramp, and the fifth roller runs over the first ramp portion of the retraction ramp. In another aspect of the invention, the purging fluid is light water.

In another aspect of the invention, the purge fluid reservoir is a reservoir disposed in the outside of the cylindrical body, and the fluid then communicates with the outlet through a hose.

In the spirit of this application, the term heavy water is used to designate water in which hydrogen is replaced by its harder isotope, deuterium ² H. In contrast, the term light water is used to designate water containing the protium isotope, in the context in which this distinction is required.

The embodiments of the present invention each have at least one of the objects 39 and / or the aspects mentioned above, but they do not necessarily have them all.

It should be understood that some aspects of the present invention, which have resulted from the attempt to achieve the aforementioned objects, cannot satisfy these objects and / or satisfy other objects, which are not included here. 43

The additional and / or alternative features, aspects and advantages of the embodiments of the present invention will become apparent from the following description, accompanied by drawings 45 and the appended claims.

RO 127982 Β1

For a better understanding of the present invention, as well as other aspects and other characteristics thereof, reference is made to the following description, to be presented in connection with the explanatory figures, which represents:

FIG. 1, longitudinal cross section of a tool for axial sampling;

FIG. 2 is a close representation of a milling assembly of an axial test tool in FIG. 1;

FIG. 3, partial section, distant, of the top plane view of a portion of the axial sample sampling tool in fig. 1;

FIG. 4 is a perspective view of a ramp arranged in the tool for taking axial samples, fig. 1;

FIG. 5, side view, on a scale, of a tool for sampling a circular sample;

FIG. 6 is a cross-sectional view of a tool for sampling the circular sample of FIG. 5, taken through line A-A of fig. 5;

FIG. 7, a close view of a portion of the sectional view of the tool for taking the circular sample from fig. 6;

FIG. 8 is a cross-sectional view of a tool for sampling the circular sample of FIG. 5, a majority of this is taken by the line D-D in fig. 5, and portions of which are taken through line E-E of fig. 5;

FIG. 9 is a cross-sectional view of a milling assembly of the tool for sampling the circular sample of FIG. 7, showing in gray the purging fluid in the cutting assembly;

FIG. 10 is a sectional view of a milling assembly of a circular tool of FIG. 7, showing, in gray, the blocked bleeding fluid to flow through the outlet holes in the cutting assembly;

FIG. 11, a sectional view of an alternative embodiment of the cutting assembly at a circular sampling tool;

FIG. 12 is a sectional view of the portion of the pressure tube from which a sample was obtained.

The sampling tool according to the invention will be described as being used to obtain samples from the pressure tubes of the nuclear reactors to be analyzed for deuterium content.

However, it should be understood that the sampling tool could be used to collect other types of samples, from other types of tubes or from arched surfaces.

In the following we will present an axial sampling tool.

The tool 100 for taking the axial samples according to the invention has a cylindrical body 122, which has a longitudinal central axis 124. An outer opening 128 is defined in the cylindrical body 122. A cutting assembly 130 is disposed in the cylindrical body 122, and is radially aligned with the outer opening 128.

The tool 100 for taking the axial samples is connected to a positioning system, not shown, which allows the exact axial positioning, for example longitudinally, of the tool 100 for taking the axial samples in the pressure tube.

The tool 100 for taking the axial samples contains a mobile trolley 132, which supports the assembly 130 cutting. The mobile trolley 132 is connected to a drive shaft 136, which is movable along the central axis 124.

The mobile trolley 132 is mounted on some rolling wheels 182 and 188, which are described in detail below. The displacement rollers 182 and 188 allow the axial movement of the mobile trolley 132. The mobile trolley 132 is moved by the use of a driving machine, for moving the shaft 136.

RO 127982 Β1

The cutting assembly 130 contains a subset 102 of oxide cutting, and a 1 subassembly 103 of sample cutting, arranged longitudinally next to each other.

The oxide cutting subassembly 102 and the sample cutting subassembly 103 are arranged opposite to each other, but it is expected that they may be arranged and adjacent to each other. 5

The oxide cutting subassembly 102 contains an oxide milling cutter 104 to cut a portion of the inner wall of the cylindrical tube 122, a support 164 oxide cartridge and an oxide container 7 160, for collecting an oxide portion that has been cut. from the inner wall of the cylindrical tube 122. 9

The sample cutter assembly 103 contains a sample cutter 105 to cut a sample from the inner wall of the tube, a sample cartridge holder 176 and a sample sample container 172, for collecting a sample that has been cut from the inner wall. of the cylindrical tube 122.

The oxide mill 104 and the sample mill 105 are curved and have a radius of the curve almost 13 similar to the pressure tube, so that the pressure tube avoids the sharp edges and stress concentrations in the pressure tube after cutting the sample. 15

A chip clip 108 is provided near the oxide mill 104, and defines an oxide container 150, and a chip clip 108 is provided near the sample mill 105 17, and defines a sample container 172. Oxide mill 104 it is connected, by means of a threaded fastener, to a cartridge 156 oxide mill. 19

The oxide mill cartridge 156 is connected by a bayonet device to the oxide cartridge holder 164. 21

Similarly, the sample mill 105 is connected, by means of a threaded fastener, to the drum 168 test mill, which is connected by a bayonet type device to the sample cartridge holder 176 23.

Two packs 178 Belleville disc / type springs are disposed under the oxide cartridge 164 and 25 under the sample cartridge holder 176, which inclines the mill oxide 104 and the sample mill 105 against the central axis 124. It is worth mentioning that other types of springs could be used instead of the 27 springs 178 disc / Belleville type.

The oxide mill 104 and the sample mill 105 are each movable between a retraction position 29 close to the central axis 124, if they are arranged inside the cylindrical body 122, and an extension position, away from the central axis 124, in the case extending into 31 parts, through the outer opening 128, to cut a portion of the oxide and the sample from the inner wall of the tube. 33

The retraction or extension of the mill oxide 104 and the sample mill 105 are related to a position of the shaft 136. The different positions of the drive shaft 136 along the 35 central axis 124 lead to the actuation of actuators, for the extension and retraction of the oxide milling 104 and the sample milling 105. 37

The actuator for the oxide mill 104 is formed by two displacement rollers 182, connected to the oxide cutting sub-assembly 102. 39

The actuator for the test cutter 105 is formed by the displacement rollers 188, connected to the subassembly 103 of the test cutter. 41

It is contemplated that a single displacement roller 182 may be connected to the oxide cutting subassembly 102, or that two rollers 188 may be connected to the sample cutting subassembly 103 43. It is also contemplated that the oxide cutting subassembly 102 and the sample cutting subassembly 103 may be actuated by actuators other than the rollers.

RO 127982 Β1

An actuating ramp 190 shown in FIG. 4, is disposed inside the cylindrical body 122 opposite the outer opening 128. The drive ramp 190 is adapted to receive the rolling rollers 182 and 188. The drive ramp 190 has portions 190a and 190b of the ramp, a flat portion 190c and two portions 190d and 190e of the slope. Each of the ramp sections 190a and 190b, the slopes 190d and 190e are adapted to receive one of the rollers 182 and the roller 188.

When the drive shaft 136 is pushed through the drive machine, to the drive ramp 190 in a cutting direction 192, shown in FIG. 2, the drive shaft 136 reaches a first position. The displacement rollers 182 roll over the portion 190a of the ramp, therefore, the oxide mill 104 extends through the outer opening 128. The oxide mill 104 reaches the inside of the pressure tube wall and therefore cuts the oxide portion from the inner wall of the pressure tube. The oxide mill 104 remains extended and cuts the oxide portion, while the displacement rollers 182 roll over the flat portion 190c. The rollers 182 are then rolled on the slope portion 190d, and the oxide mill 104 moves back to the retracted position.

The drive shaft 136 continues to move in the direction of cutting 192, to the second position, the displacement roller 188 rolls over the portion 190b of the ramp, thereby extending the test mill 105 by opening the outer 128, cutting the sample from the location where the oxide was removed.

The sample nozzle 105 remains extended and cuts the sample, while the displacement roller 188 rolls over the flat portion 190c. When the displacement roller 188 runs on the slope portion 190c, the sample roller 105 moves back to its retracted position.

the overall height of the sample cutting subassembly 103 being greater than the total height of the oxide cutting subassembly 102, the sample being cut deeper than the oxide portion of the inner wall of the pressure tube.

This is achieved by providing blades, not shown, between the test mill 105 and the cartridge 168 of the test mill.

whereas portions 190b and 190e are shorter than portions 190a and 190d, and the sample is also shorter than the oxide portion.

As can be seen from FIG. 12, a depth D _s of cut, made with the sample cutter 105, is consequently greater than a depth D 'of cut, made with the cutter 104 of oxide.

The sample cutter 105 is also narrower than the oxide cutter 104, and therefore a cutting width W _s made by the sample cutter 105 is smaller than a cutter width W made by the cutter. 104 of oxide. It is considered that the actuating ramp 190 may have an alternative form for creating a different cutting model.

A purge fluid passage network 140 evacuates the purge fluid to a cutting location, while cutting the oxide portion through the oxide mill 104 and the sample through the 105 milling sample.

The purge fluid passage network 140 extends through the cutting assembly 130, and is supplied with purge fluid from a 107 purge fluid reservoir, shown in FIG. 1. The purge fluid is preferably light water.

The purge fluid reservoir 107 is in the form of a reservoir which is located in the cylindrical body 122. It is contemplated that other types of purging fluid reserves 107 may be used. For example, the hydraulic pressure may be provided from an external reservoir, which supplies, through a hydraulic hose, the tool 100 for taking axial samples.

RO 127982 Β1

The purge fluid reservoir 107 is connected to the purge fluid network 140 through a feed hose 109. A displacement piston 123 is actuated by an actuating shaft 127. Being moved by the actuating shaft 136, the shaft 127 moves the piston 123 3 toward the center of the reservoir 107 of purging fluid, which raises the pressure of the fluid from the reserve 107 of purging fluid. 5

Two electromagnetic valves 116a and 116b, which will be described in more detail below, control the flow between the supply hose 108 and the purge fluid passage network 140.

The purge fluid network 140 contains a passage in the oxide milling subassembly 102 9 and a passage in the test mill subassembly 103. The passage in the oxide milling subassembly 102 is connected to a vent valve 116a, and terminates at holes 110a and 110b of 11 oxide discharge. The passage from the subassembly 103 sample cut is connected to a vent valve 116b, and terminates in the holes 112a and 112b of the sample outlet. 13

The holes 110a and 110b for the removal of the oxide are located towards the front and, respectively, towards the back of the cutting edges of the milling oxide 104 with respect to the direction of cutting 192. The oxide outlet ports 110a and 15 110b are used to discharge the purge fluid at the cutting location of the oxide portion. The holes for the sample evacuation 112a and 112b are located towards the front 17 and, respectively, towards the back of the cutting edge of the test cutter 105, with respect to the cutting direction 192. 19

The sample outlet ports 112a and 112b are used to discharge the purge fluid to the sample cutting location. 21 In an alternative embodiment, the oxide cutting milling subset 102 contains only an oxide outlet 110a or 110b, and the sample cutting subassembly 103 contains only a single outlet 112a or 112b.

In another alternative embodiment, only the oxide cutting subassembly 102 or the sample cutting subassembly 103 has outlet holes.

Discharging the purge fluid at the cutting location allows an operator to obtain a reliable analysis of the deuterium concentration of the sample, without leaking into the pressure tube. The discharge of the purge fluid to the passage network 140 of the purge fluid is controlled 29 by two ventilation valves 116a and 116b, located between the cut assembly 130 and the reserve 107 of purge fluid. The ventilation valves 116a and 116b are connected to the supply 107 of 31 purging fluid through the supply hose 108. The venting valve 116a is attached to the oxide cutting subassembly 102 by a fixing pin 109. The venting valve 116b is attached to the sample cutting subassembly 103 through an unrepresented fastening pin. The pins ensure that the venting valve 116a moves in unison with the oxide cutting subassembly 102, and the 35 venting valve 116b moves in unison with the sample cutting subassembly 103. When the oxide cutting subassembly 102 moves up, the venting valve 116a moves upward, and when the sample cutting subassembly 103 moves upward, the venting valve 116b moves upward. 39 During operation, the tool 100 for taking axial samples is inserted into the pressure tube and moves to the desired longitudinal position in the pressure tube, by adjusting the position 41, using the positioning system. The drive shaft 136 is moved using the drive machine in the first position, therefore, determines the movement of the subassembly 102 of 43 oxide cutting to the driving ramp 190 in the cutting direction 192. The displacement rollers 182 move up to the ramp portion 190a which, in turn, moves the oxide mill 104 to contact it with the pressure tube.

RO 127982 Β1

Simultaneously, the venting valve 116a moves from the central axis 124, and the purge fluid is released into the passage network 140 of the purge fluid inside the oxide cutting subassembly 102 and is finally discharged through the holes 110a and 110b of oxide discharge. The oxide mill 104 removes the oxide portions when the displacement rollers 182 run along the ramp portion 190a and the flat portion 190c, until the rollers descend on the slope portion 190d, leaving a recess in the pressure tube. When the displacement rollers 182 descend on the slope portion 190d, the vent valve 116a moves to the central axis 124, thus preventing fluid communication between the reservoir 107 of the purge fluid and the oxide cutting subassembly 102. During the cutting, the chips of the oxide portion that enters the opening between the oxide milling 104 and the clip 108 for the chips are captured in the oxide container 160.

The drive shaft 136 is therefore moved to a second position, thus moving the sample cutter assembly 103 to the drive ramp 190.

The sample is cut by the sample mill 105, inside the tube wall in the tube location where the oxide layer was cut with mill oxide 104, for the displacement roller 188 to run on the ramp portion 190b and the flat portion 190c.

Simultaneously, the displacement piston 123 moves and pressurizes the purge reservoir 107, and the vent valve 116b moves back from the central axis 124, and the purge fluid is released to the purge fluid passage network 140 inside the subassembly 103. of sample cutting, and finally it is evacuated through the holes 112a and 112b of the evacuation.

The test cutter 105 removes the sample when the displacement roller 188 runs on the ramp portion 190b and the flat portion 190c. Simultaneously, the displacement piston 123 moves and pressurizes the supply 107 of purge fluid, and the vent valve 116b moves back from the central axis 124, and the purge fluid is released to the network 140 of the purge fluid passing into the subassembly 103. of sample cutting, and finally it is evacuated through the holes 112a and 112b to evacuate the sample. The test cutter 105 removes the sample when the displacement roller 188 runs along the ramp portion 190b and the flat portion 190c, until the roller roller 188 descends on the slope portion 190e, leaving a recess in the pressure tube.

When the displacement roller 188 descends on the slope portion 190c, the venting valve 116b moves to the central axis 124, thus preventing fluid communication between the reservoir 107 of purge fluid and the sample cutter assembly 103. During the cutting, the sample chips enter the opening between the oxide mill 105 and the clip 108 of the chips, and are captured in the sample container 172.

Another embodiment of the tool 200, for the sampling of circular samples, will be presented below.

A tool for sampling circular samples has a cylindrical body 222 having a central longitudinal axis 224. The cylindrical body 222 has a plurality of pads provided with sliding bearings 226, located externally, to support the tool 200 for sampling circular samples, when the tool 200, for sampling circular samples, is disposed within the pressure tube.

An outer opening 228 is defined in the cylindrical body 222. A cutting assembly 230 is disposed in the cylindrical body 222 and is radially aligned with the outer opening 228.

The tool 200 for the sampling of circular samples is connected to a positioning system that allows precise axial and angular positioning in the pressure tube. A protective sleeve, not shown, is disposed over the tool 200 for taking circular samples, for closing the outer opening 228, when the tool 200 for taking circular samples is not used.

RO 127982 Β1

The tool 200, for taking circular samples, the positioning system and the protective sleeve 1 are arranged in a support, not shown, which is preferably with wheels, to facilitate the positioning of the support trolley. 3

Referring to FIG. 6, the tool 200 for the sampling of circular samples contains a movable trolley 232, which supports the cutting assembly 230. The movable trolley 232 is connected 5 by a connecting coupling 234 to an output shaft 236. The connecting coupling 234 is connected to the output shaft 236 through the grooves. An electric motor 238 is used for turning 7 of the output shaft 236, which, in turn, rotates the moving trolley 232 and the cutting assembly 230. 9

The 238 electric motor is preferable to be a DC motor, but other types of motors can be used. 11

It is envisaged that the electric motor 238 can be coupled to a different cutting assembly 230. For example, the output shaft 236 of the electric motor 238 can be connected to the 13 drive shaft which, in turn, is connected to the moving trolley 232.

The cutting assembly 230 will be described in detail. 15

The cutting assembly 230 includes a sub-assembly 202 of the oxide mill, and a sub-assembly 203 of the test mill. The oxide milling subassembly 202 contains an oxide milling 204 that cuts a 17 portion of the inner wall of the pressure tube, a support 264 oxide cartridge and a container 260 of oxide, for collecting the oxide portion inside the tube wall. The oxide mill 204 is connected by a threaded fixing device 254 to an oxide cartridge 256. A clamp 258 for the oxide chips is connected to the cartridge 256 of the oxide mill. The clamp 258 for the oxide chips 21 retains the cut tube portion 204 of the oxide mill inside the oxide container 260, formed between the oxide mill 204, the cartridge 256 of the ox mill, and the clip 258 for the 23 ox chips. The cartridge 256 of the oxide mill is connected by a bayonet-type mount 262 to the support cartridge 264. The sample mill subassembly 203 contains a sample 25 mill 205 that cuts a sample from the inner wall of the tube, a sample cartridge holder 276 and a sample container 272 for sample collection. The sample mill 205 is connected, 27 by means of a threaded fastening device 266, to a cartridge 268 of the test mill. A sample chip clamp 270 holds the sample cut with the sample cutter 205 inside the sample container 272, 29 formed between the sample cutter 205, the sample cartridge 268 and the sample cutter clamp 270.

The cartridge 268 of the test mill is connected by a bayonet-type mount 274 to 31 the sample cartridge support 276.

The oxide mill 204 and the sample mill 205 are radially arranged, opposite each other. 33

It will be taken into account that the oxide mill 204 and the sample mill 205 can be arranged at different angles to each other. The oxide mill 204 and the sample mill 205 are preferably made of 35 carbide. The oxide mill 204 is larger than the sample mill 205, for the reasons explained below. 37

Two Belleville 278 disc / spring springs are disposed between the oxide cartridge holder 264 and the sample cartridge holder 276, thus moving the 204 oxide mill and 39 the 205 sample mill away from each other.

A 280 thread fixing device is inserted into the sample cartridge holder 276 and 41 is contiguous with the oxide cartridge holder 264, thus retaining the Belleville 278 disc / type springs between the two brackets 264 and 276. Other types will also be considered. of springs can be used in place of 43 Belleville 278 disk / type springs.

The oxide mill 204 and the sample mill 205 are movable each between a retraction position, 45 near the central axis 224, where they are disposed within the cylindrical body 222, and an extended position away from the central axis 224, where they extend into part, by opening the outer 47 228, to cut the inner wall of the pressure tube.

RO 127982 Β1

The withdrawal or extension of the oxide mill 204 and the sample mill 205 are related to the position of the output shaft 236. Different positions of the output shaft 236 are initiated by different drives, for actuating the extension or retraction of the oxide mill 204 and the sample mill 205. The oxide milling device 204 contains two displacement rollers 282, connected either to a part of the cartridge 268 of the test mill or to springs 284. Two coil springs 284 are connected to the support cartridge 264 by two caps. 286 springs, and two helical 284 springs are connected to the sample cartridge holder 276 by two 286 spring caps.

The coil springs 284 tilt the oxide mill 204 to the retraction position.

The actuator for the sample mill 205 consists of two displacement rollers 288, connected either to one side of the oxide mill cartridge 256 or to helical springs 284. The coil springs 284 tilt the sample mill 205 to the retracted position. It will be taken into account that only a travel roller 282 or 288 could be used. It will be taken into account that the oxide mill 204 and the sample mill 205 could be driven by other types of actuators. For example, it will be taken into account that the moving rollers 282, 288 could be replaced with fixed cams.

An extension ramp 290 is disposed within the cylindrical body 222, opposite the outer opening 228. The extension ramp 290 is adapted to receive the displacement rollers 282 and 288. Extension ramp 290 has a ramp portion, a flat portion and a slope portion. When the output shaft 236 rotates to a first position, the displacement rollers 282 roll over the extension ramp 290, thus extending to the oxide mill 204 by the outer opening 228, and the milling ox 204 remaining in the extended position, as the rollers 282. displacement to run over the flat portion of the extension 290. The displacement rollers 282 then run on the slope portion of the extension ramp 290, and the oxide mill 204 moves back to its retraction position.

Similarly, when the output shaft 236 rotates to a second position, the displacement rollers 282 run over the ramp portion of the extension ramp 290, the sample mill 205 is moved to its extension position and remains in the extended position, the rollers 288 displacement running on the flat portion of the ramp 290 extension.

When the displacement rollers 288 run on the slope of the extension ramp 290, the sample roller 205 moves back to its retracted position. It will be taken into account that the extension ramp 290 may have an alternative shape, to create a different cutting pattern.

A purge fluid passage network 240, for discharging the purge fluid to a cutting location, while cutting a portion inside the tube wall, through the oxide mill 204 and the sample through the sample mill 205, will be described below.

The purge fluid passage network 240 extends through the cutting assembly 230, and is supplied with purge fluid from the purge fluid reserve 207, the purge fluid being preferably light water. The purge fluid reservoir 207 is in the form of a reservoir, which is located in the cylindrical body 222. It should be noted that other types of purging fluid reservoirs 207 may be used.

For example, the hydraulic pressure may be taken from an external reservoir which supplies a hydraulic hose to the sample tool 200.

The purge fluid reservoir 207 is connected to the purge fluid network 240 through a hydraulic hose 208. An electromagnetic valve 216, having radial pistons 217 and 219, described in detail below, controls the flow between the hydraulic hose 208 and the purge fluid passage network 240.

RO 127982 Β1

The purge fluid passage network 240 contains the radial and 240b axial passes 240a 1 in the oxide cutting subassembly 202, and the axial and 240d radial crossings 240c in the subassembly.

203 sample cutting. The radial passage 240a is connected to the radial piston 217 and to the 3 axial passage 240b, and the axial passage 240c is connected to the radial piston 219 and to the passage

240d radial. The axial passage 240b ends at two oxide outlet holes 210, and the radial passage 240d ends at two sample evacuation holes 212.

It will be noted that only one of the outlet holes 210 and 7 212 were represented. The outlet holes 210 of the oxide discharges the purge fluid to the cutting location of the portion inside the tube walls, and the sample outlet ports 212 discharge the fluid. 9 bleeding at the sample cutting location. An orifice 210 for evacuating the oxide is located in the cartridge 256 of the oxide mill, towards a cutting edge 204 of the oxide mill against the cutting direction 292, 11 such as the rotation direction of the output shaft 236, shown in FIG. 8. Another oxide outlet 210 is located in the mill 204 of the oxide, towards the back of the cutting edges of the milling cutter 13

204 oxide compared to the cutting direction 292. Similarly, two sample outlet ports 212 are located at the front and at the rear respectively of the cutting edges of the sample mill 205 15.

It is also contemplated that the fluid passage network 240 may be replaced by 17 two independent networks, one containing the radial and 240b axial passes, and the other containing the axial and 240d axial passes 240c. 19

It is also contemplated that the sampling tool 200 may contain the purge fluid passage network 240, connected only to the outlet holes 210 oxide 21, or only to the ports 212 the sample drain.

In an alternative embodiment, the mill oxide subassembly 202 contains a single oxide outlet 23, located at the rear or in front of the oxide mill 204.

Similarly, a single sample outlet port 212 may be located in the front portion 25 or behind the sample mill 205.

The two radial pistons 217 and 219 of the electromagnetic valve are connected 27 through a connecting shaft 221. The radial pistons 217 and 219 alternately move upward, for opening the axial crossings 240a and radial 240b in the oxide cutting subassembly 202, 29 and the axial and 240c radial crossings 240c in the sample cutting subassembly 202. The movement of the radial pistons217 and 219 depends on the position of the cutting assembly 230 and, therefore, on the position of the output shaft 236, as will be described in detail below. Specifically, the radial piston 217 of the electromagnetic valve 216 controls the flow of the purge fluid from the inlet 33 of the oxide cutting subassembly 202, and the radial piston 219 of the electromagnetic valve 216 controls the flow of the purge fluid at the inlet of the test cutter assembly 203. It is contemplated that the electromagnetic valve 216 may contain only the radial piston 217 or only the radial piston 219, to supply purge fluid only to oxide mill 204 or sample sample mill 205, respectively. It is also contemplated that the sampling tool 200 may contain two separate electromagnetic valves, each 39 electromagnetic valve being able to selectively communicate with one of the sub-assemblies 202 of oxide cutting and 203 of cutting of sample, with reserve 207 of fluid for purging. 41

With a fastening pin 209 the test mill subassembly 203 and the piston 219 radially are fixed. The fastening pin 209 ensures that the radial piston 217 moves in unison with the oxide cutting subassembly 43 202, and that the radial piston 219 moves in unison with the sample cutting subassembly 203. It is contemplated that the fixing pin 209 may alternatively be located between the oxide cutting subassembly 202 and the radial piston 217.

RO 127982 Β1

It is also contemplated that the radial piston 217 may be fixed to the oxide cutting sub-assembly 202 by a first fixing pin, and to the sample cutting sub-assembly 203 by another fixing pin.

The discharge of the purge fluid is provided by a network 240 of the passage of the purge fluid, pressurized, and the purge fluid is discharged, due to the hydraulic pressure, to the cutting location through the holes 210 and 212 of the outlet.

An operating mode of the electromagnetic valve 216 will be described below.

The electromagnetic valve 216 is operatively connected to the output shaft 236, to allow the two radial pistons 217 and 219 to open and close at the same time as the movement of the oxide cutting subassembly 202 and the cutting steel subassembly 203 respectively. sample. It is envisaged that the electromagnetic valve 216 may not be connected to the same shaft as the cutting assembly 230, but nevertheless be arranged in such a way as to coordinate its opening with a displacement of the cutting assembly 230.

When the output shaft 236 rotates to the first position where the oxide mill 204 extends through the outer opening 228, the radial piston 217 is moved away from the central axis 224, thus allowing fluid communication between the oxide cutting subassembly 202 and the reservoir 207. of purging fluid.

The radial piston 219 moves closer to the central axis 224, thus preventing fluid communication between the sample cutting subassembly 203 and the purging fluid reservoir 207. When the output shaft 236 rotates to the second position where the sample cutter 205 extends through the outer opening 228, the radial piston 219 is moved away from the central axis 224, thus allowing fluid communication between the test cutter assembly 203 and the reserve 207. purging fluid. The radial piston 217 moves closer to the central axis 224, thus preventing communication between the oxide cutting sub-assembly 202 and the purging fluid reservoir 207.

In order to obtain a sample from within the wall of the pressure tube, including a common laminated region, the tool 200 for taking circular samples is inserted into the tube. The positioning system is used to set the angular and axial position, if the sample will be collected from inside the tube.

For collecting a sample, the cutting assembly 230 uses gravity.

As a consequence, the sample is normally collected from the upper half of the tube, that is, between the 9 o'clock and 3 o'clock positions. The tool 200 for circular sampling is locked to the position where the cutting assembly 230 is aligned with a location where the sample it is desired to be cut, and the bearing plates 226 are actuated to hold the tool 200 for circular sampling in position, by pushing it towards the inner wall of the tube. The electric motor 238 is then actuated to cut from the inner wall of the pressure tube.

The electric motor 238 turns the movable trolley 232 in the direction indicated by the cutting direction 292, thus turning the cutting assembly 230 in the same direction.

The output shaft 236 rotates to the first position. When the displacement rollers 282 reach the drive ramp 290 and run on it, the oxide cutting subassembly 202 and the radial piston 217 move upward.

The movement of the oxide cutting subassembly 202 induces the oxide mill 204 to pass, in its extended position, through the outer opening 228. The movement of the radial piston 217 induces the communication between the oxide cutting subassembly 202 and the purging fluid reservoir 207.

RO 127982 Β1

For the displacement rollers 282 to run over the actuating ramp 290, the oxide mill 204 1 moves in the arc of a circle along a circumference of the inner wall of the pressure tube, and cuts an oxide layer. at the same time, the radial piston 217 opens the axial passes 240a and the radial 240b 3, the purging fluid flows through the axial 240a and 240b radial passes, and is discharged through the oxide outlet 210 at the cutting location. 5

The purge fluid replaces the heavy water in the portion inside the wall of the tube being cut. In a preferred embodiment, the oxide mill 204 cuts a little deeper than the 7 oxide layer to ensure complete removal of the oxide.

The clamp 258 of the chips causes the chip from the oxide layer to twist inside the container 260, to be cut.

The 278 disc / Belleville type springs tilt the mill 204 of oxide to the surface of the 11 pressure tube, thus allowing the milling machine to maintain contact with the surface even if the surface is uneven, and thus allow the tool 200 for circular sampling to be used 13 in. -a variety of diameters of pressure tubes.

When the displacement rollers 282 come into contact with the drive ramp 290, the helical springs 15 284 influence the cutting assembly 230 back toward the inner wall of the cylindrical body 222, and consequently the oxide mill 204 moves back to the retracted position. At the same time, the piston 217 radially moves downward and closes the axial 240a and 240b radial crossings, thus preventing fluid communication between the oxide cutting subassembly 202 and the purging fluid reservoir 207 19. Once the oxide cutting subassembly 204 is in contact with the inner wall of the tube, the chip in the oxide layer falls within the oxide container 260. 21

The output shaft 236 then continues to rotate to the second position. When the displacement rollers 288 come into contact with the drive 290 and roll over it, 23 the cutting assembly 230 moves to the top, extending the sample roller 204 by opening the outer 228. at the same time, following the rotation of the output shaft 236, the piston 25

219 radially moves away from the central axis 224, opens the axial passages 240c and 240d radially, and allows communication between the sample cutting subassembly 204 and the reservoir 207 of 27 purging fluid.

When the displacement rollers 288 run on the displacement ramp 290, the sample roller 205 moves in a circle arc along a circumference of the inner wall of the test tube, and cuts a sample from the inner wall of the tube at the location of tube, when the oxide layer 31 was cut with milling oxide 204. The purging fluid flows through the axes 240c and 240d radially, thus displacing the heavy water from the portion of the wall, if the sample is cut, and is expelled through the sample outlet hole 212.

The 270-pin clip determines that the sample chip enters the sample container 272 35 and is cut. The 278 disc / Belleville type springs tilt the sample mill 205 to the surface of the tube, thus allowing the milling machine to maintain contact with the surface even if it is irregular.

When the rollers pass over the extension ramp 290, the helical springs 284 tilt 39 the assembly 230 cutting back towards the inner wall of the cylindrical body 222 and, consequently, the sample mill 205 moves back to the retraction position, and the piston 219 radially closes 41. the 240c axial and 240d radial passages. When the sample cutter is no longer in contact with the inner wall of the pressure tube, the sample cutter falls inside the sample container 272.

In an alternative embodiment, shown in FIG. 11, the cutting assembly 230 is provided with rubber parts 231a and 231b, used as buffers.

RO 127982 Β1

It is contemplated that the rubber parts 231a and 231b may be metallic.

The rubber parts 231a and 231b extend from the oxide cutting subassembly 202 and the sample cutting subassembly 203 respectively. Parts 231a and 231b of rubber are used to prevent the flow of heavy water into the pressure tube from the removal of light water, injected at the location where the inner wall is cut. The rubber part 231a is part of the oxide mill cartridge 256, but may alternatively be part of the oxide cartridge support 264. Similarly, the rubber part 231b is part of the cartridge 268 of the test mill, but may, alternatively, be part of the cartridge carrier 276. Alternatively, only a rubber part 231a or 231b may be used on the cutting subassembly 202 or 203, by positioning the part upstream of the oxide mills 204 and sample 205. Parts 231a and 231b of rubber must not seal the cutting site perfectly, as long as they cause the heavy water to be removed from the cutting place.

Because the displacement rollers 288 are larger than the displacement rollers 282, the sample roller 205 cuts the interior of the pressure tube wall deeper than the oxide roller 204. It is envisaged that the displacement rollers 282 may be of the same height as the displacement rollers 288, and the overall height of the sample cutting subassembly 103 may be greater than the total height of the oxide cutting subassembly 102. This is achieved by providing the slats, not shown, between the sample mill 205 and the cartridge mill 268.

The depth D of the cut made by the milling _and the sample 205 is consequently greater than the depth D of cutter 204 made of _an oxide.

The sample cutter 205 is narrower than the oxide cutter 204, and therefore the width W _s of the cut made by the sample cutter 205 is smaller than the width W _o of the cut made by the cutter 204. Since the displacement rollers 282 have a smaller diameter than the displacement rollers 288, the spring defined by the sample mill 205 is shorter than the spring defined by the oxide mill 203, when it moves relative to the surface of the inner wall of the tube. pressure.

Therefore, the sample chip is shorter than the oxide chip. The deeper, narrower and shorter cuts made by the sample mill 205 ensure that the sample is free of oxide, so that it provides a reliable analysis of the deuterium concentration of the sample, which is used to determine the useful life of the pressure tube.

Also, the displacement of heavy water from the regions in which they are cut, as described above, ensures a reliable analysis of the deuterium concentration of the sample. A reliable analysis of the deuterium concentration of the sample can be obtained without the need to isolate and drain the pressure tube. Moreover, since the oxide mill 204 and the sample mill 205 travel on the circumference of the inner wall of the pressure tube, they will not be affected by the surface variations in the axial direction of the tube. Therefore, the tool 200 for taking circular samples can be used to obtain samples in the common, laminated region of the pressure tube.

Once the samples have been obtained, the tool 200 for circular sampling is unlocked, the bearing plates 226 are released and the tool 200 for circular sampling is retracted, inside the cylindrical body 222.

The sample contained in the sample container 272 is then transferred to a flask contained in the basket. The steps above, starting from establishing the angular and axial position, if the sample is collected, can be repeated to obtain other samples, in other locations in the tube. After all the samples have been collected, the protective sleeve is disconnected from the end, and the trolley is removed from the pressure tube.

Finally, the vial containing the sample is taken over. The steps above refer to a possible method 1 of providing the tool 200 for taking circular samples inside the pressure tube, to obtain samples. It should be understood that other methods of delivering the 200 3 circular sampling tool are also possible and are targeted.

Modifications and improvements of the embodiments described above, of the present invention, may become apparent to those skilled in the art. The description above is intended to be exemplary rather than limiting. Therefore, the scope of the present invention 7 is intended to be limited only by the appended claims.

Claims (20)

1. Tool for sampling, designed to obtain samples from an inner wall of the pressure tubes of nuclear reactors, having a cylindrical body, with a central axis, provided with an outer opening, a drive shaft, disposed in the body cylindrical, along the central axis, a first cutting assembly, connected to the drive shaft, and having a first milling cutter and being movable between a retraction position, if the first milling cutter is disposed inside the cylindrical body, at a a first distance from the central axis, and an extension position, if the first mill extends at least in part, by means of an outer opening, to a second distance from the central axis, which is greater than the first distance; the first milling subassembly moves to the extension position when the shaft moves to a first position, thus causing the first milling mill to cut a portion of the inner wall of the tube, a second milling subassembly, connected to the drive shaft, having a second milling shaft and being movable between a retraction position, in which the second mill is disposed inside the cylindrical body, at a third distance from the central axis, and an extension position, where the second mill extends in part , by the outer opening at a fourth distance from the central axis, the fourth distance being greater than the third distance, thus causing the second mill to cut the sample from the inner wall of the tube from a location discovered by cutting the portion from the inner wall of the of the first milling tube, a first actuating device, connected to the first cutting subassembly, for moving the first fr between the retraction position and the extension position, when the motor shaft moves to the first position, a secondary actuator connected to the second cutting subassembly for moving it between the retraction position and the extension position, then when the motor shaft is moved to the second position, at least one of the first cutting subassembly and the second cutting subassembly having an outlet, characterized in that at least the first cutting subassembly or the second subassembly the cutter has an outlet, a purge valve that selectively connects the outlet with a reserve of purge fluid, the purge valve being fixed to one of the first cutter assembly or the second cutter assembly, so that the bleed valve moves with at least the first cutting subassembly or the second subassembly d e cutting, provided with the outlet, the purge valve communicating with the supply of the bleed fluid when at least the first cutting subassembly or the second cutting subassembly, which is provided with the outlet, is in the extension position , following the discharge of the purging fluid through the outlet hole on the inner wall of the tube, during cutting by the first milling or the second milling, in one of the areas corresponding to the first or second milling. A sampling tool according to claim 1, characterized in that the outlet is a first outlet, the first cutting subassembly having the first outlet, the second cutting subassembly having the second outlet. Sampling tool according to claim 2, characterized in that the purge valve connects the first purge port and the second purge port with the purge fluid reservoir, the purge valve connects the first orifice. outlet with the purge supply reservoir when the drive shaft moves to the first position, and the purge valve connects the second outlet port with the purge supply reservoir, when the shaft moves to a second position. RO 127982 Β1 4. A sampling tool according to claim 2, characterized in that the purge valve is a first purge valve that connects the first purge hole with the purge fluid reservoir, a second purge valve is attached to the one. the second 3 subassembly cut and connect the second bleed port with the bleed fluid reservoir, the first bleed valve connects the first bleed hole with the bleed fluid reservoir 5, when the motor shaft moves to the first position, and the second purge valve connects the second purge hole with the 7 purge fluid reservoir, when the motor shaft moves to the second position. 5. A sampling tool according to claim 4, characterized in that the bleed valve is located axially between the first cutting subassembly and the second cutting subassembly. 11 6. A sampling tool according to claim 4, characterized in that, when the first purge valve allows the first purge port to be communicated with the 13 purge fluid reservoir, the second purge valve then prevents the second orifice from communicating. purge reservoir, and when the second purge valve 15 allows communication between the second purge port and the purge reservoir, the first purge valve then impedes communication between the first purge port and the purge reservoir 17. 7. A sampling tool according to claim 1, characterized in that the shaft can rotate, and the first and second positions of the shaft are angular positions. 8. A sampling tool according to claim 7, characterized in that the purge valve is an electromagnetic valve. A sampling tool according to claim 7, characterized in that the first cutting subassembly is located on the opposite side of the second cutting subassembly. 25 10. A sampling tool according to claim 1, characterized in that the motor shaft is axially movable and the first and second positions of the motor shaft 27 are longitudinal positions with respect to the cylindrical body. 11. A sampling tool according to claim 10, characterized in that the purge valve is a vent valve. 12. A sampling tool according to claim 10, characterized in that the first cutting subassembly is located towards the second cutting subassembly with respect to the cutting direction of the first mill and the second mill. 33 A sampling tool according to claim 1, characterized in that the outlet is a first outlet, and at least one of the first cutting subassembly or the second cutting subassembly has the first purging and, also, the second purging port. 37 14. A sampling tool according to claim 13, characterized in that the first purging hole is located in front of the purging hole corresponding to the first milling machine and the second milling machine, relative to the cutting direction of the first milling machine and the milling machine. -the second mill, the second purging port extends to the corresponding purging port 41 of the first mill and the second mill. A sample tool according to claim 1, characterized in that the outlet hole extends to the purging hole corresponding to the first mill and the second mill. 45 RO 127982 Β1 1 16. A sampling tool according to claim 1, characterized in that the outlet is located in front of the purging hole corresponding to the first milling machine and 3 of the second milling machine, relative to the cutting direction of the first milling machine and the second milling machine. 17. A sampling tool according to claim 1, characterized in that 5 that the purge valve is fixed to the first milling subassembly and to the second milling subassembly by a fastening pin. 7 18. A sampling tool according to claim 1, characterized in that the purging fluid is light water. 9 19. A sampling tool according to claim 1, characterized in that the purge fluid reservoir is a reservoir disposed outside the cylindrical body, the fluid 11 communicating with the purging port through a connecting hose. 20. A sampling tool according to claim 1, characterized in that 13 that the purge fluid reservoir is a reservoir located inside the cylindrical body.