DE20016120U1 - Measuring arrangement for measuring containers for radioactive goods - Google Patents

Description

ZENZ · HELBER · HOSBACH & PARTNERS

Patent Attorneys · European Patent Attorneys · 64673 Zwingenberg, Scheuergasse 24

Tel.: 06251-73008 · Fax: 06251-73156

Kraftanlagen Nukleartechnik GmbH, Im Breitspiel 7, 69126 Heidelberg

Measuring arrangement for clearance measurements of containers for radioactive transport goods

The invention relates to a mobile measuring arrangement for measuring the clearance of containers for radioactive transport goods with a measuring device whose counting tube is guided in successive individual steps at a predetermined distance over the entire surface of the container wall to be measured, whereby a measurement of the radioactive contamination of a partial surface section of the container wall is carried out between each successive individual step.

For containers used for the transport of radioactive goods, it must be ensured that they are checked after unloading and before returning from the loading and unloading areas, which are naturally located in specially enclosed areas, to determine whether they are impermissibly contaminated with radioactive substances and therefore could pose a danger to people or the environment when transported outside the loading or unloading area on public land. This inspection of the containers, which must be carried out each time before the container is moved,

ner into a generally accessible surrounding area is also known as clearance measurement. Up to now, this clearance measurement has been carried out by specially commissioned and trained persons who use a suitable measuring device that is sensitive to radioactive radiation to examine all external and, in special cases, internal surfaces of the container that are accessible to third parties for the presence of radioactive contamination. The radiation protection officer holds the measuring device or the counting tube of the measuring device in his hand and carries out the measurements one after the other for areas corresponding to the measuring surface of the respective counting tube, whereby a large number of measurements have to be carried out both vertically and horizontally (for vertical surfaces) or in horizontal directions at right angles to one another (for wall or floor surfaces). This method of working is inconvenient for the person carrying out the measurement, especially since the measuring device with the counting tube has to be positioned by hand and during the measurement the counting tube has to be held at a specified distance from the surface to be measured. Inaccuracies and incorrect measurements cannot therefore be completely ruled out from the outset, especially since the large number of individual measurements taken one after the other in each container, where the counting tube must be held statically in position by the person measuring, means that static holding forces must be applied which lead to fatigue.

In contrast, the invention is based on the object of creating a measuring arrangement for the devices used for clearance measurements, which ensures precise positioning of the counting tube of the measuring device and largely completely relieves the operator of holding forces and thus also increases the reliability of the measurements.

This object is achieved according to the invention by a measuring arrangement in which in the wall area of the container to be measured

ners mountable guide means which guide a holder for the counting tube at a specified distance in at least two coordinate directions that are perpendicular to each other and parallel to the surface to be measured. The guide means therefore ensure on the one hand that the prescribed measuring distance of the counting tube from the surface to be measured is necessarily maintained and also allow the holder for the counting tube to be fixed in the selected measuring position, which relieves the operator of physical strain.

In the case where the measuring arrangement according to the invention is intended for the clearance measurement of vertical external walls, the guide means have at least one guide rail which can be attached to the container parallel to and above the upper edge of the surface of the container wall to be measured, on or into which a guide element in the form of at least one skid or roller provided at the upper end of a horizontal slide extending substantially over the entire height of the surface of the wall to be measured can be displaced horizontally.

In a preferred embodiment, the horizontal slide has at least two parallel, elongated vertical longitudinal profiles which are kept at a distance from one another, to the upper end of which the guide element is attached via at least one upper spacer element which projects horizontally towards the container, the horizontal cantilever distance of which is dimensioned such that the slide has a predetermined distance from the surface of the container wall to be measured in the area of its upper end, and that the slide has at least one further lower spacer element which projects towards the container wall in an area offset towards its lower end, the free end of which facing away from the guide profile can be supported on the container wall, the cantilever distance of the lower spacer element being dimensioned such that the slide can also be supported at its lower end.

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is held at a specified distance from the surface of the container wall to be measured. The interaction of the upper and lower spacer elements ensures that the holder for the counting tube and thus also the distance of the counting tube from the surface to be measured is set to the specified measuring distance.

It can be advantageous if the cantilever distance of the upper and lower spacer elements is designed to be variable within a predetermined range. For this purpose, the spacer elements can, for example, be designed in two parts and telescopically movable into one another and fixable in selectable displacement positions. In particular, the lower spacer element(s) can also be designed as a threaded shaft screwed into a threaded hole in the horizontal slide, the container-side end of which is expediently provided with an enlarged head. By changing the screw-in depth of the threaded rod in the associated threaded hole, the length 0 of the threaded shaft section protruding from the threaded hole in the direction of the container can be changed and thus the cantilever distance of the spacer element designed in this way. Changes to the cantilever distance of the horizontal slide from the surface to be measured can be necessary in two cases. Firstly, when the container has protruding supports such as information signs etc. in areas of the wall surfaces to be measured. Then, when measuring in this area, the distance between the counter tube and this protruding area must be changed accordingly. On the other hand, such a change in the distance may also be necessary if measuring instruments of different types are used in which the specified measuring distance between the counter tube and the wall surface to be measured is different.

The holder for the counting tube preferably has a vertically displaceable support that can be fixed in selectable displacement positions on or in the longitudinal profile.

files of the horizontal slide. In the area defined by the length of the guide rail that can be attached to the container on the one hand and the length of the vertical longitudinal profiles of the horizontal slide on the other hand, the counting tube can then be aligned to any point on the wall surface to be measured, so that the entire wall surface can be checked without gaps by successive step-by-step scanning of the surface sections corresponding to the respective measuring surface (the entire wall).

The vertical slide is expediently guided in a vertical direction by rollers engaging in the longitudinal profiles of the horizontal slide. The design is then expediently made such that one end of a flexible pulling element, e.g. a rope or a chain, engages the vertical slide, the other end of which is attached to a winding drum that can be driven by an operator in the opposite direction of rotation. When the winding drum is operated by the operator to wind up the pulling element, the vertical slide is moved upwards in a vertical direction against its own weight. When the winding drum rotates in the opposite direction, the vertical slide moves downwards due to its own weight.

Basically, the winding drum can be operated by a motorized rotary drive assigned to it. However, such a motorized drive can also be dispensed with if the traction element is attached at one end to the upper edge area of the vertical slide and is initially guided essentially vertically upwards over a deflection element provided on the horizontal slide, preferably a deflection roller mounted freely rotatably on the horizontal slide, and then in a downward direction to the horizontal slide which can be rotated by an operator at a gripping height.

The operator can then rotate the winding drum manually by holding it in place on a shaft that is rotatably mounted on or in the horizontal slide, and to the free end of which protrudes from the bearing a rotary actuator in the form of a crank or handwheel is attached. The operator then changes the height setting of the vertical slide by turning the crank or handwheel in the required direction.

To fix a height setting, a releasable clamping or locking device should be provided that fixes the vertical slide in the height setting selected by the operator in the horizontal slide. Suitable non-positive clamping or positive locking ratchet mechanisms are known per se.

In an advantageous development of the invention, the vertical slide is provided with a support platform protruding from the side of the horizontal slide facing away from the container, on which the control and measuring unit processing the measuring signals of the counter tube can be placed.

The counting tube is arranged on the vertical slide at the intended measuring distance from the surface, pointing in the direction of the container wall surface to be measured.

For the mobile use of the measuring arrangement according to the invention at different measuring stations, it is advantageous if the guide rail that can be attached to the container is composed of a number of guide rail sections that can be connected or separated as required. For transport from one measuring station to another, the guide rail can then be dismantled into correspondingly shorter sections. For measuring the front and rear vertical end wall of a container, the guide rail to be used there can be

The guide rail can then be assembled from a correspondingly reduced number of guide rail sections.

In an advantageous embodiment, the guide means provided for measuring the clearance of the interior walls of a container have a carrier carriage that can be moved on the floor surface of the container and in which the counting tube can be mounted in a parallel alignment to the wall surface to be measured. The carrier carriage can preferably be moved parallel to the floor in at least two coordinate directions that run at right angles to one another.

On the carrier slide, at least one elongated guide profile protruding at right angles to the inner surface of the top wall of the container is advantageously provided for a vertical slide carrying the holder for the counting tube, which can be displaced in a vertical direction and fixed in selectable displacement positions. 20

To measure the inner surface of the top wall of the container, the bracket is then attached to the upper end of the vertical slide in such a way that the counting tube is held in a measuring position parallel to the inside of the container top wall.

To measure the inner surface of the vertical container walls, the holder for the counting tube is arranged on the vertical slide in such a way that the counting tube is held in a measuring position parallel to the inner surfaces of the vertical wall of the container.

The invention is explained in more detail in the following description in conjunction with the drawing, which shows:

Fig. 1 is a side view of the outer surface of a vertical side wall of a

Fig. 2

Container with the measuring arrangement mounted on the container for measuring this side wall for radioactive contamination;

a plan view of a region of the top wall of the container immediately adjacent to the side wall shown in Fig. 1, seen in the direction of arrow 2 in Fig. 1;

Fig. 3 ■ a view of a portion of the

the front wall immediately adjacent to the side wall of the container visible in Fig. 1, seen in the direction of arrow 3 in Fig. 1; and

Fig. 4 is a schematic side view of a

for the clearance measurement of the inner surface of the top wall - and in a modified form also the inner surface of the side wall - of a container.

0 converted measuring arrangement.

Figures 1 to 3 show a schematic representation of a measuring arrangement, designated in its entirety by , designed in the manner according to the invention, which is used to measure the clearance of the outer vertical surface of the side wall 12 of a container 14. The measuring arrangement 10 has a guide rail 18 which is fastened in the region of the upper edge of the side wall at a distance above the container top wall 16 and which is attached to the container 14 in a suitable manner so that it can be removed. In Fig. 1, this is indicated schematically by a series of supports 20 which are spaced apart from one another in the horizontal direction, without the exact manner in which the supports 20 are connected to the guide rail 18 or the container 14 being shown.

In Fig. 1 it is also indicated that the guide rail 18 is composed of three guide rail sections 18a, 18b, 18c, which are plugged together or connected in some other way to form the actual guide rail 18 when a container 14 is prepared for measurement. Dividing the guide rail 18 into several individual sections has the advantage that the measuring arrangement can be dismantled for storage and transport when not in use and then requires less storage or transport space. For the clearance measurement of the end walls of the containers, the guide rail to be used there can then be composed of a smaller number of guide rail sections 18a, 18b corresponding to the smaller width of the end walls.

The guide rail holds a horizontal slide 22 that can be moved in the horizontal direction, which in the case shown is formed by two parallel elongated longitudinal profiles 24 that are held at a distance from one another and are connected, for example, at the upper and lower ends by a welded cross profile 26 and 28, respectively. Two spacer elements 30 that protrude at right angles to the container 14 are attached to the upper cross profile 26, each of which rotatably holds a roller 32 that engages in the profiled guide rail 18 that is open at the top and thereby enables the horizontal slide 22 to be easily moved in the horizontal direction in front of the side wall 12. At the lower end of the longitudinal profiles, spacer elements 34 in the form of threaded shafts are provided, which engage in a threaded hole in a threaded bushing 36 fastened to the associated longitudinal profile 24 and are supported on the container side via a support shoe 38 on the side wall 12. The spacer elements 30 and 34 therefore hold the horizontal slide 22 at a predetermined distance from the outer surface of the side wall 12.

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In the space between the longitudinal profiles 24, a vertical slide 40 is arranged so that it can be moved in a vertical direction. In order to guide the vertical slide 40 precisely and easily, it has rollers 42 in its corner areas which engage with the profiles 24. At the upper end of the vertical slide 40, a flexible pulling element, e.g. a wire rope 44, is attached, which is deflected via a deflection roller 46 rotatably mounted on the upper cross profile 26 and is guided in a downward direction to a winding drum 48. The winding drum 48 is rotatably mounted in a bearing block 50 fastened to the left longitudinal profile 24 in Fig. 1, with a handwheel 52 which can be turned by an operator being attached to the front end of the shaft of the winding drum 48 which is guided through the bearing block. Depending on the direction of rotation, sections of the wire rope 44 are then wound onto or unwound from the winding drum, whereby the vertical slide 40 is raised or lowered in the longitudinal profiles 24. The vertical slide 42 can then be fixed in a selected vertical position in the horizontal slide 22 by means of a suitable clamping or locking device (not shown). This clamping or locking device can either act between the vertical slide and the longitudinal profiles 24 of the horizontal slide 22 or can also be designed as a clamping or locking mechanism which acts between the winding drum 48 and the bearing block.

In the space between the container side wall 12 and the longitudinal profiles 24 of the horizontal slide, the counting tube 56 provided with a rectangular measuring surface is arranged on the vertical slide 40, which is thus held at the distance from the outside of the side wall 12 predetermined by the spacer elements 30 and 34 and can be brought into any measuring position in front of the side wall 12 by moving the horizontal slide 22 and the vertical slide 40.

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The measuring distance of the counting tube 56 can be changed by changing the cantilever distance of the spacer elements 30, 34, for which in the case of the lower spacer element 34 provided with a threaded shaft it is only necessary to screw the threaded shaft into or out of the threaded sleeve 36. By a corresponding design of the upper spacer element 30 with a variable cantilever distance - not shown in the drawing figures - it can be achieved that the vertical slide can be aligned overall by a certain amount so that the distance to the side wall 12 can be changed, whereby the longitudinal profiles 24 guiding the vertical slide 40 continue to run parallel to the side wall 12.

The vertical slide 40 carries on its side facing away from the container a support platform 60 on which the control and measuring unit 62 processing the measurement data supplied by the counting tube can be placed.

It is clear that the design of the clearance measuring device described above in connection with the clearance measurement of the outside of a vertical container side wall 12 can also be designed for the clearance measurement of the outside surface of the top wall 16 of the container 14 with appropriate adaptation. Instead of a guide rail 18, guide rails are then provided above the opposite longitudinal edges of the container top wall 16, on which the horizontal slide with horizontally mounted 0 longitudinal profiles for the slide carrying the counting tube 56, which can be moved at right angles to the horizontal slide 22, can be moved. This slide, which can also be moved in a horizontal plane when measuring the top wall 16, is then better referred to as a "cross slide" to distinguish it from the vertically movable vertical slide 40 of the described embodiment.

Fig. 4 shows a schematic representation of a measuring arrangement 10' intended for the clearance measurement of the inner surfaces of a container, which in the special case is designed such that the counting tube 56 is held at the predetermined measuring distance below the inner surface of the top wall 16 of the container. The horizontal slide 22 described in the embodiment according to Figs. 1 to 3 is formed here by a carrier slide 22' which can be moved on rollers 32', on the upper side of which at least one longitudinal profile 24' protrudes, into which the vertical slide 40' in the form of a profile protruding from the upper end of the longitudinal profile 24' is arranged so as to be displaceable in the vertical direction and can be fixed in selectable height positions by a clamping device. A cantilever profile 30' is attached at right angles to the free upper end of the profile forming the vertical slide 40', which supports the counting tube 56 which in the case shown is held in the horizontal position aligned parallel to the container top wall 16. In addition, a counting tube 56 is shown in dash-dotted lines in a vertical orientation parallel to the inside of a container side wall 12.

The control and measuring unit 62 is attached to the longitudinal profile 24' of the carrier carriage 22' at a height suitable for reading and operation and is connected to the counting tube 56 via a flexible cable harness 61. It is clear that the measuring arrangement 10' is therefore basically suitable for measuring the clearance of the horizontal inner surfaces of the cover wall 16 as well as for measuring the clearance of the inner surfaces of vertical container walls.

Within the scope of the inventive concept, modifications and further developments of the described embodiments of the measuring device according to the invention can be implemented, some of which have already been mentioned in the preceding description. For example, a motor drive, for example by stepper motors, is conceivable for both the horizontal slide and the vertical slide, in which case

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It can be considered to control these stepper motors via an automatic program control so that the horizontal slide and/or the vertical slide are automatically moved to the next measuring position after each measurement.

Claims (18)

1. Mobile measuring arrangement ( 10 ; 10 ') for measuring the clearance of containers ( 14 ) for radioactive transport goods, with a measuring device whose counting tube ( 56 ) is guided in successive individual steps at a predetermined distance over the entire surface of the container wall to be measured, wherein a measurement of the radioactive contamination of a partial surface section of the container wall is carried out between successive individual steps, characterized by guide means which can be mounted in the wall area of the container ( 14 ) to be measured and which guide a holder for the counting tube ( 56 ) so that it can be moved at a predetermined distance in at least two coordinate directions running at right angles to one another and parallel to the surface to be measured. 2. Measuring arrangement according to claim 1, characterized in that the guide means provided for the clearance measurement of vertical outer walls have at least one guide rail ( 18 ) which can be attached to the container parallel to and above the upper edge(s) of the surface of the container wall to be measured, on or into which a guide element in the form of at least one skid or roller ( 32 ) provided at the upper end of a horizontal slide ( 22 ) extending essentially over the entire height of the surface of the wall to be measured is horizontally displaceable. 3. Measuring arrangement according to claim 2, characterized in that the horizontal slide ( 22 ) has at least two parallel elongated vertical longitudinal profiles ( 24 ) held at a distance from one another, at the upper end of which the guide element is attached via at least one upper spacer element ( 30 ) projecting horizontally to the container, the horizontal cantilever distance of which is dimensioned such that the slide ( 22 ) has a predetermined distance from the surface of the container wall to be measured in the region of its upper end, and that the slide ( 22 ) has at least one further lower spacer element ( 34 ) projecting towards the container wall in an area offset in the direction of its lower end, the free end of which facing away from the guide profile can be supported on the container wall, the cantilever distance of the lower spacer element ( 34 ) being dimensioned such that the slide is also held in its lower area at the predetermined distance from the surface of the container wall to be measured. 4. Measuring arrangement according to claim 3, characterized in that the cantilever distance of the upper and lower spacer elements ( 30 ; 34 ) is variable within a predetermined range. 5. Measuring arrangement according to claim 3 or 4, characterized in that the holder for the counting tube ( 56 ) has a vertical slide ( 40 ) which is displaceable in the vertical direction and can be fixed in selectable displacement positions and is guided on or in the longitudinal profiles ( 24 ) of the horizontal slide ( 22 ). 6. Measuring arrangement according to claim 5, characterized in that the vertical slide ( 40 ) is guided in the horizontal slide ( 22 ) so as to be displaceable in the vertical direction by rollers ( 36 ) engaging in the longitudinal profiles ( 24 ). 7. Measuring arrangement according to claim 5 or 6, characterized in that one end of a flexible pulling element ( 44) acts on the vertical slide (40 ) , the other end of which is fastened to a winding drum ( 48 ) which can be driven in rotation in opposite directions by an operator. 8. Measuring arrangement according to claim 8, characterized in that the pulling element ( 44 ) is fastened with its one end to the upper edge region of the vertical slide ( 40 ) and is initially guided essentially vertically upwards over a deflection element provided on the horizontal slide, preferably a deflection roller ( 46 ) mounted freely rotatably on the horizontal slide, and is then guided in a downward direction to the winding drum ( 48 ) which is mounted on the horizontal slide ( 22 ) at a height within reach of an operator and can be driven in rotation. 9. Measuring arrangement according to claim 8, characterized in that the winding drum ( 48 ) is mounted in a rotationally fixed manner on a shaft which is rotatably mounted on or in the horizontal slide ( 22 ), to the free end of which shaft leading out of the bearing a rotary actuating element in the form of a crank or a handwheel ( 52 ) is fastened. 10. Measuring arrangement according to claim 9, characterized by a releasable clamping or locking device which fixes the vertical slide ( 40 ) in the height setting selected by the operator in the horizontal slide ( 22 ). 11. Measuring arrangement according to one of claims 5 to 10, characterized in that the vertical slide ( 40 ) is provided with a support platform ( 60 ) for the control and measuring unit ( 62 ) of the counting tube ( 56 ) which protrudes from the side of the horizontal slide ( 22 ) facing away from the container. 12. Measuring arrangement according to one of claims 5 to 11, characterized in that the counting tube ( 56 ) is arranged on the vertical slide ( 40 ) directed in the direction of the surface of the container wall to be measured at the intended measuring distance from the surface. 13. Measuring arrangement according to one of claims 2 to 12, characterized in that the guide rail ( 18 ) attachable to the container is composed of a number of guide rail sections ( 18 a, 18 b, 18 c) which can be selectively connected to and separated from one another. 14. Measuring arrangement according to claim 1, characterized in that the guide means provided for the clearance measurement of inner walls of a container have a carrier carriage ( 22 ') which can be moved on the bottom surface of the container and on which the counting tube ( 56 ) can be attached in parallel alignment to the wall surface to be measured. 15. Measuring arrangement according to claim 14, characterized in that the carrier carriage ( 22 ') can be moved parallel to the ground in at least two coordinate directions running at right angles to each other. 16. Measuring arrangement according to claim 14 or 15, characterized in that on the carrier slide ( 22 ') at least one elongated guide profile ( 24 ') protruding at right angles to the inner surface of the cover wall ( 16 ) of the container ( 14 ) is provided for a vertical slide ( 40 ') carrying the holder for the counting tube ( 56 ), which can be displaced in the vertical direction and fixed in selectable displacement positions. 17. Measuring arrangement according to claim 16, characterized in that the holder is fastened to the upper end of the vertical slide ( 40 ') in such a way that the counting tube ( 56 ) is held in a measuring position aligned parallel to the inside of the container top wall ( 16 ). 18. Measuring arrangement according to claim 16, characterized in that the holder for the counting tube ( 56 ) is arranged on the vertical slide ( 40 ') such that the counting tube ( 56 ) is held in a measuring position aligned parallel to the inner surfaces of the vertical walls of the container ( 14 ).