EP0054944A1 - Storage equipment for radioactive material - Google Patents

Abstract

In a device for storing radioactive material with an inner container (5) holding the material and an outer container (2, 4) surrounding the inner container made of a ceramic material, it is important that mechanical and thermal effects that occur during storage and possibly during transport Loads do not lead to the destruction of the outer container. In order to achieve this, it is provided that the inner container (5) is held in the outer container (2, 4) by a widely distributed engagement with the inner wall, the engagement being a sole frictional engagement, a frictional engagement supported by adhesive bonding or a sole adhesive bonding. The outer wall of the inner container can be in direct engagement with the inner wall of the outer container, or there is an engagement element (12) with the inner container in a non-positive and / or positive connection (13, 13a, 14), the outer wall of which engages with the inner wall of the Outer container is present. An engagement element designed as a frictional engagement element preferably consists of a slotted (12a) sleeve part and an abutment (13) connected to the inner container. Instead of an engagement element with a large engagement surface, it is also possible to use a multiplicity of smaller engagement elements with an essentially uniform distribution of their individual engagement surfaces over a large area of the inner wall of the outer container. In the case of frictional engagement supported by adhesive (K) or adhesive engagement alone, the adhesive is designed such that the thermal behavior of the holder of the inner container in the outer container is not disturbed.

Description

The invention relates to a device for storing radioactive material with an inner container receiving the material and an outer container surrounding the inner container made of a ceramic material.

When the device is used, there is a thermal load on the inner container and thus also a thermal load on the outer container. Since the materials used for the outer container and inner container mostly differ in their thermal expansion coefficients, there is a risk that the radial and axial thermal stresses occurring in the known device will reach values which lead to damage or destruction of the outer container.

Furthermore, when using the device, there is a risk that acceleration forces are applied to the device. The outer container has at least one insertion opening to be closed with a lid only after the inner container has been introduced. In the known devices, there is a risk that if the device is used as intended, shock loads are applied to the bottom or the lid by the inner container those that lead to stress peaks that promote the brittle fracture of the ceramic outer container. Even if the material is not destroyed by the sudden acceleration forces, the connection between the closure parts of the outer container and the base body of the outer container can be broken.

It is the object of the present invention to provide a device of the type mentioned above, in which dynamic loads are removed safely and free of notches in the wall of the outer container.

This object is achieved by the features in the characterizing part of claim 1.

The acceleration forces are thus transmitted to the inner container on a large area of the outer container evenly or without a notch effect.

The engagement, which is distributed over a large area, can be achieved, on the one hand, via one or a few larger engagement surfaces, or, on the other hand, via a large number of smaller individual engagement surfaces evenly distributed over the inner wall of the outer container, as long as the total engagement surface required for securely holding the inner container is present. However, the individual smaller engagement surfaces must not be so small that notch effects occur can. According to the invention, the engagement is a sole frictional engagement, a frictional engagement supported by adhesive bonding or a sole adhesive bonding.

The outer wall of the inner container is in direct engagement with the inner wall of the outer container or there is at least one engagement element with the inner container in a non-positive or positive connection, the outer wall of which engages with the inner wall of the outer container.

If the outer wall of the inner container lies directly on the inner wall of the outer container, a large engagement surface, in particular a friction engagement surface, is achieved from the outset. If only one or a small number of engagement elements are used, these bear larger engagement surfaces on the inner wall of the outer container in order to achieve a uniform introduction of the forces and a good heat transfer from the inner container to the outer container. If a plurality of engagement elements are used, these lie with their smaller individual engagement surfaces in a uniform distribution, forming a sufficient total engagement surface on a large area of the inner wall of the outer container. In order to establish a non-positive connection to the outer container, in the present application and in the claims, a weld, soldering, gluing is understood in addition to a frictional connection.

The outer wall of the inner container or the outer wall or the engaging surfaces of the engaging element or the whole engaging element are preferably made of a metallic material which ensures good heat transfer from the inner container to the outer container. In the case of frictional engagement, the size of the frictional engagement is also determined by the choice of material.

In order to limit the stress resulting from the different thermal expansion coefficients of the materials used for the outer container and inner container to permissible values and to adjust the size of the normal forces acting on the outer container inner wall, it is preferably provided that the outer wall of the inner container or the frictional engagement element or the frictional engagement elements can be prestressed are. When using a frictional engagement element as the engagement element, this preferably consists of a slotted sleeve part and an abutment connected to the inner container. The sleeve part can be pretensioned in the circumferential direction, so that its outer surface lies against the outer container with a defined force. Other prestressable engaging elements are described in the description below.

The abutment can be formed by a separate component or by welding, soldering, gluing or the like.

If other shapes are used for the frictional engagement elements, care must be taken that a prestress can be impressed on them such that they act on the inner wall of the outer container with a predetermined normal force.

If no separate frictional engagement element or a plurality of such frictional engagement elements are used, the wall of the inner container is preferably provided with at least one bead or the like which extends in the longitudinal direction and opens towards the outer surface of the inner container. The outer wall of the inner container then lies against the inner wall of the outer container and the pre-tension that is set can be predetermined by designing the bead.

The inner cross-section of the outer container and the outer cross-section of the inner container have a cylindrical cross-section, cylinder-like being understood to mean all bodies not delimited by a polygonal lateral surface. This means that the application is in particular not limited to circular cylindrical cross sections. Here, in particular because of the material used for the outer container and the associated manufacturing process, deviations from the cylindrical shape can occur, which can be compensated for using separate frictional engagement elements. When using a plurality of frictional engagement elements in a substantially uniform distribution, the frictional engagement elements can be formed individually and can be connected individually to the inner containers or the friction closing elements are integrally formed with one another at least in groups. Furthermore, if a plurality of frictional engagement elements are used, these are preferably tongue-shaped.

Inadmissible increases in the contact pressure of the inner container or the friction element (s) on the inner wall of the ceramic outer container as a result of thermal stresses are avoided when using a sleeve-like friction element through the axially extending bead or the axially extending slot, which reduces the circumference of the container wall itself or the frictional engagement element under thermal load. When using a plurality of friction-locking elements that extend in the longitudinal direction of the inner container or are designed like tongues, no impermissible increases in the contact pressure can occur. If a slotted sleeve is used to build up the frictional engagement element, a frictional engagement element assembly with at least two sleeves inserted into one another can be provided to increase the frictional forces, the slots of the two sleeve parts being offset in the circumferential direction. The sleeve part and the abutment can be formed in one piece with one another or separately from one another.

It is particularly advantageous to design the inner wall of the outer container like a truncated cone in the area of the frictional engagement form and adapt the outer wall of the inner container or the frictional engagement element to this configuration. In the frustoconical design of the surfaces in frictional engagement, when the sleeve is moved in the event of a load in the axial direction, the normal forces and thus the frictional forces are progressively increased in that the prestressing force is increased in accordance with the truncated cone angle by compressing the sleeve or the inner container. The large end surface of the truncated cone is adjacent to one end of the outer container or the center of the outer container.

If the large end surface of the truncated cone is adjacent to one end of the outer container and the corresponding engagement surface of the sleeve part of the frictional engagement element is adapted to this configuration, displacement of the frictional engagement element is limited by wedging the sleeve part of the frictional engagement element with the inner container if the displacement force in the container is effective = When using two friction locking elements and a double truncated cone-like design of the inner wall of the outer container corresponding to the diabolo toy, an impermissibly large displacement of the inner container and thus a load on the bottom and lid are excluded.

A frictional engagement along conical surfaces is also possible if no separate frictional engagement elements are used, but instead the outer wall of the inner container together with the inner wall of the outer container are designed accordingly.

The inner container can be held in the inner container of the outer container solely by frictional engagement over a large area. be; but it is also possible that the frictional connection is supported by an adhesive that does not hinder the thermal behavior of the system. Ceramic adhesives are particularly suitable for this, as will be explained further below.

Further subclaims relate to advantageous refinements of the device according to the invention.

The device will now be described in more detail in various embodiments with reference to the attached figures.

• Fig. 1 einen Längsschnitt durch einen Außenbehälter und als Reibschlußelemente ausgebildete Eingriffselemente einer ersten Ausführungsform der Vorrichtung, wobei der Innenbehälter in Seitenansicht dargestellt ist,
• Fig. 2 eine Prinzipdarstellung zur Erläuterung der Montagefolge bei Gebrauch der Vorrichtung gemäß Fig. 1,
• Fig. 3 einen Längsschnitt längs der Linie III-III in Fig. 4 durch Außenbehälter und Reibschlußelemente einer zweiten Ausführungsform,
• Fig. 4 einen Schnitt längs der Linie IV-IV in Fig. 3,
• Fig. 5 ein entsprechender Schnitt durch eine dritte Ausführungsform,
• Fig. 6 einen Schnitt längs der Linie VI-VI in Fig. 5 mit einer vergrößerten Detaildarstellung des Sperrklinkeneingriffes zwischen Innenhülse und Außenhülse,
• Fig. 7 einen Schnitt längs der Linie VII-VII in Fig. 8 einer weiteren Ausführungsform,
• Fig.. 8 einen Schnitt längs der Linie VIII-VIII in Fig. 7,
• Fig. 9 einen Schnitt durch eine weitere Ausführungsform eines Reibschlußelementes,
• Fig.lo einen Schnitt längs der Linie X-X in der Fig. 9,
• Fig.ll eine als Teilschnitt dargestellte Seitenansicht einer weiteren Ausführungsform eines Reibschlußelements mit einer vergrößerten Darstellung der Bolzenverbindung zwischen Hülsenteil und Widerlager,
• Fig.12 eine Aufsicht auf das Reibschlußelement gemäß Fig. 11,
• Fig.13 eine als Teilschnitt dargestellte Seitenansicht eines weiteren Reibschlußelements,
• Fig.14 eine Aufsicht auf das Reibschlußelement gemäß Fig. 13,
• Fig.15 einen Teilschnitt durch eine andere Ausführungsform des Reibschlußelementes,
• Fig.16 eine Aufsicht auf das Reibschlußelement gemäß Fig. 15,
• Fig.17 einen Teilschnitt durch eine andere Ausführungsform des Reibschlußelements,
• Fig.18 eine Aufsicht auf das Reibschlußelement,
• Fig.19 eine als Teilschnitt dargestellte Seitenansicht eines geschlitzten Hülsenteiles mit wellenartigem Schlitz,
• Fig.2o eine der Fig. 19 vergleichbare Darstellung eines weiteren Hülsenteils mit Spiralschlitz,
• Fig.21 einen Teilschnitt durch eine Vorrichtung mit Innen-und Außenbehälter, wobei die Außenwandung des Innenbehälters in vorgespanntem Reibschluß an der Innenwandung des Außenbehälters anliegt,
• Fig.22 einen Teilschnitt längs der Linie XXII-XXII in der Fig. 21,
• Fig.23 einen Teillängsschnitt durch Innenbehälter und Außenbehälter mit in Sicken des Innenbehälters in Längsrichtung eingeschobenen geschlitzten Reibschlußrohren,
• Fig.24 eine Ausführungsform mit im wesentlichen geradzylindrischen Innebenhälter und Außenbehälter, wobei in einen 'zwischen den beiden Behältern verbleibenden Ringraum in gleichmäßiger Verteilung sich in axialer Richtung erstreckende Vorspannelemente eingeschoben sind,
• Fig.25 eine Ausführungsform, vergleichbar Ausführungsform Fig.24, bei der in den verbleibenden Ringraum sich in Längsrichtung erstreckende und in Umfangsrichtung gewellte Reibschlußelemente eingeschoben sind,
• Fig.26 eine zum Teil als Schnitt dargestellte Seitenansicht einer weiteren Ausführungsform, wobei auf der Oberfläche des Innenbehälters kammartige Reibschlußelemenbefestigt sind, die in Reibschluß an der Innenwandung des Innenbehälters anliegen,
• Fig.27 einen Schnitt längs der Linie XXVII-XXVII in Fig.26,
• Fig.28 eine Seitenansicht mit nach außen vorstehenden Reibschlußzungen und nach innen vorstehenden Zungen zur Halterung des Reibschlußkorbes am Innenbehälter,
• Fig.29 einen Teilschnitt längs der Linie XXIX-XXIX in der Fig.28,
• Fig.30 eine Seitenansicht einer weiteren Ausführungsform eines Reibschlußkorbes mit nach außen gebogenen Reibschlußzungen,
• Fig.31 einen Teilschnitt längs der Linie XXXI-XXXI in der Fig.30,
• Fig.32 eine zum Teil als Schnitt dargestellte Seitenansicht einer Ausführungsform der Vorrichtung mit Halterung eines balgenartigen Innenbehälters in einem im wesentlichen geradzylindrischen Außenbehälter,
• Fig.33 einen Schnitt längs der Linie XXXIII-XXXIII in der Fig.32.

It shows:

• 1 shows a longitudinal section through an outer container and engagement elements designed as frictional engagement elements of a first embodiment of the device, the inner container being shown in a side view,
• 2 shows a schematic diagram to explain the assembly sequence when using the device according to FIG. 1,
• 3 shows a longitudinal section along the line III-III in FIG. 4 through the outer container and frictional engagement elements of a second embodiment,
• 4 shows a section along the line IV-IV in FIG. 3,
• 5 shows a corresponding section through a third embodiment,
• 6 shows a section along the line VI-VI in FIG. 5 with an enlarged detailed illustration of the pawl engagement between the inner sleeve and the outer sleeve,
• 7 shows a section along the line VII-VII in FIG. 8 of a further embodiment,
• 8 shows a section along the line VIII-VIII in FIG. 7,
• 9 shows a section through a further embodiment of a frictional engagement element,
• Fig.lo a section along the line XX in Fig. 9,
• Fig.ll a side view, shown as a partial section, of another embodiment of a frictional engagement element with an enlarged view of the bolt connection between the sleeve part and the abutment,
• 12 is a plan view of the frictional engagement element according to FIG. 11,
• 13 shows a side view of a further frictional engagement element, shown as a partial section,
• 14 is a plan view of the frictional engagement element according to FIG. 13,
• 15 shows a partial section through another embodiment of the frictional engagement element,
• 16 is a plan view of the frictional engagement element according to FIG. 15,
• 17 shows a partial section through another embodiment of the frictional engagement element,
• 18 is a plan view of the frictional engagement element,
• 19 shows a side view, shown in partial section, of a slotted sleeve part with a wave-like slot,
• 20 an illustration comparable to FIG. 19 of a further sleeve part with a spiral slot,
• 21 shows a partial section through a device with an inner and outer container, the outer wall of the inner container abutting the inner wall of the outer container in a pretensioned frictional engagement,
• 22 shows a partial section along the line XXII-XXII in FIG. 21,
• 23 shows a partial longitudinal section through the inner container and outer container with slotted friction pipes inserted in the longitudinal direction in the beads of the inner container,
• 24 shows an embodiment with an essentially straight cylindrical inner container and outer container, wherein prestressing elements extending in the axial direction are inserted into an annular space remaining between the two containers in a uniform distribution,
• 25 shows an embodiment, comparable embodiment of FIG. 24, in which friction locking elements which extend in the longitudinal direction and are corrugated in the circumferential direction are inserted into the remaining annular space,
• Fig. 26 is a side view, partly in section, of a further embodiment, comb-like frictional engagement elements on the surface of the inner container are attached, which rest in frictional engagement on the inner wall of the inner container,
• 27 shows a section along the line XXVII-XXVII in FIG. 26,
• 28 shows a side view with outwardly projecting friction locking tongues and inward projecting tongues for holding the friction locking basket on the inner container,
• 29 shows a partial section along the line XXIX-XXIX in FIG. 28,
• 30 shows a side view of a further embodiment of a friction locking basket with friction locking tongues bent outwards,
• 31 shows a partial section along the line XXXI-XXXI in FIG. 30,
• 32 shows a side view, partly as a section, of an embodiment of the device with a bellows-like inner container being held in an essentially straight-cylindrical outer container,
• 33 shows a section along the line XXXIII-XXXIII in FIG. 32.

In the device according to FIG. 1, the outer container 1 made of a ceramic material consists of a cylindrical jacket 2, a bottom 3 and a lid 4, the bottom 3 and lid 4 being connected in a suitable manner to the free end faces of the jacket 2.

An inner container 5, which consists of a cylindrical jacket 6, a base 7 and a cover 8, is introduced into the outer container. In the embodiment shown, the inner container is made of metal, so that the base and lid are connected to one another along weld seams 9 (it is also possible for the cover 6 and base 7 to form a deep-drawn unit). The inner container 5 is filled with heat-releasing radioactive material in a manner not shown.

A manipulation pin 10 is attached to the lid 8 for handling the inner container.

The inner container 5 is held in the outer container 1 by two frictional engagement elements 11 which are intended to derive the dynamic forces acting on the inner container 5 into the ceramic wall.

Each frictional engagement element 11 consists of a sleeve part 12 provided with a longitudinal slot 12a and a sleeve end ring 13 provided with a slot 13a, which can be connected to the sleeve part by means of a connection technique shown in broken lines in FIG. 1. Suitable connection technology e.g. a bolt connection.

The sleeve parts 12 encompass the inner container when the device is assembled with a predetermined play S. The bottom 9 of the inner container is supported by a spring ring 14 on the sleeve end ring of the lower friction element, while the cover 8 is supported by a spring ring 14 on the sleeve end ring 13 of the upper friction element, wherein the manipulation pin 1o engages in the free space of the sleeve end ring 13.

The assembly of the upper part of the device will now be explained in more detail with reference to FIG. 2.

The sleeve part 12 can be reduced in diameter with the aid of a tool, not shown, by reducing the width of the slot 12a to such an extent that it can be inserted into the cylindrical jacket 12. The dimensions are chosen so that after the tool has been removed from the sleeve part 12, it rests with a defined radial prestress on the inner wall of the outer container 1. Then the inner container 5 is inserted (it is assumed that the lower frictional engagement element has already been installed) until it rests on the lower spring ring 14. The upper spring ring 14 is then introduced and the sleeve end ring 13 is connected to the free end face of the sleeve part 12, the slots 12a and 13a being aligned.

As can be seen from Fig. 1, the sleeve end rings 13 are held at a distance from the bottom 3 or at a distance from the cover 4 to be put on.

When the device is accelerated in the axial direction of the container, the inner container is held in such a way that the bottom 3 and lid 4 of the outer container are not exposed to shock loads, since the sleeve end rings 13 serving as abutments absorb the axial forces and introduce them into the sleeve (of course, the connection between Sleeve part 12 and sleeve end ring 13 must be designed so that this introduction takes place safely). The forces are diverted into the ceramic material via the large-area frictional engagement between the outer surface of the sleeve parts 12 and the inner wall of the cylindrical jacket 2, without this being exposed to shock loads or notch effects.

The arrangement is designed such that, after the clamping tool has been removed, the sleeve parts apply the desired force to the cylindrical inner surface, but at the same time the radial slot 12a is not closed, but still has a predetermined slot width. An inadmissible increase in the contact pressure of the sleeve part 12 on the cylindrical jacket 2 as a result of thermal stresses resulting from different coefficients of thermal expansion can thus be avoided.

In order to facilitate the insertion of the frictional engagement element 11 into the cylindrical casing 2, the sleeve part 12 is provided with an insertion truncated cone 12b.

For the attachment of the inner container 5 in the outer container 1, no special processing of the ceramic outer container is required, at most one processing of green compacts.

In the outer container 15 of the embodiment shown in FIGS. 3 and 4, the jacket has a straight cylindrical outer surface 16a, while the inner surface 17 consists of a central straight cylindrical section 17a and two frustoconical surface sections 17b adjoining the outside. In deviation from the embodiment according to FIG. 1, the bottom and lid of the outer container 15 have a hood character. The design of the base and lid is not essential for the present invention.

The same reference numerals have been used for the inner container as in the embodiment according to FIG. 1. Four locking pins 18, which are used simultaneously as manipulation pins, are provided on the lid and bottom in a uniform distribution in the circumferential direction.

The frictional engagement elements 19 are formed in one piece and consist of a sleeve part 2o provided with a slot 2oa and abutment sectors 21 which cover the floor or the Overlay cover 8 in the manner shown in FIGS. 3 and 4. The inner surface 2ob of the sleeve part 2o is of straight cylindrical design, while the outer surface 2oc is also designed as a truncated cone, adapting to the frustum angle of the frustoconical surface section 17b. In the assembled state, the inner surface 2ob has play S from the outer surface of the inner container 5. In each abutment sector, a locking opening 21a is provided in such a way that after the frictional engagement element 19 has been placed on the inner container and after a corresponding relative rotation of the frictional engagement element with respect to the inner container, an axial separation between the two components connected in such a positive manner is no longer possible. If one disregards the fact that the surface section 17a can be relatively long, the configuration of the two outer surfaces 2oc can be compared with the diabolo toy, in which a rotating body with a corresponding truncated cone configuration is used. In the case of an axial displacement forced by axial acceleration forces, for example from above in FIG. 3, the frictional engagement between the outer surface 2oc of the upper frictional engagement element 19 and the associated surface section 17b of the outer container 15 is progressively increased, since the normal force acting on the surface section 17b is compressed by the Sleeve part 2o is increased according to the cone angle of the frustoconical surfaces in engagement. The extent of the compression of the sleeve part is preferably limited by or by the predetermined slot width of the slot 2oa previous installation of the inner surface 2ob with reduction of the game S on the outer surface of the inner container 5. Which measure is effective depends on the design of the slot width and its size in comparison to the game S.

In the embodiment shown in FIGS. 5 and 6, an inner container 22 which is stepped at its ends is held in an outer container 24 by means of a two-piece friction-locking element 23. The two-piece frictional engagement element consists of an inner sleeve 25 and an outer sleeve 26, which are each provided with a longitudinal slot 25a and 26a. The two sleeves 25 and 26 are set into one another in such a way that the slots 25a and 26a are offset from one another. In the embodiment shown, the slots are essentially diametrically opposed.

The inner sleeve consists of a frusto-conical sleeve part 25b and a frustoconical abutment collar 25c formed integrally therewith, the inner surface of which rests on a corresponding bevel of the stepped portion 22a of the stepped inner container. In contrast to the sleeve part 2o of the frictional engagement element 19 according to FIG. Figures 3 and 4 in this embodiment, the frusto-conical sleeve part 25b has a uniform wall thickness, so that the play S between the cylindrical outer surface of the inner container 22 and the frustoconical inner surface of the sleeve part 25b increases from the outside inwards. The outer surface of the sleeve part 26b abuts the inner surface of the frustoconical outer sleeve 26, which is also of a substantially uniform wall thickness.

The thus also frustoconical outer surface of the outer sleeve 26 lies on a frustoconical surface section 27a of the outer container shell 27, the lid and bottom not being shown.

By using the two slotted sleeves inserted into each other, the frictional forces can be compared Use of only a single slotted sleeve can be increased. If the frictional forces between the two sleeves 25 and 26 are sufficient, the outer surface of the outer sleeve could also be fixed to the surface 27a by gluing or welding. In the sense of the present application, the outer sleeve 26 would then have to be regarded as the inner wall of the outer container with respect to the frictional engagement.

Of course, the inner container does not necessarily have to be a stepped one, but it is easier to construct from two cylindrical sections. The truncated cone surface 27a widens from the outside inwards and then merges into an oppositely acting surface 27b, which in turn merges into a straight cylindrical surface (not shown). The insertion truncated cone section 26b of the outer sleeve 26 is adapted to the angle of inclination of the surface 27b.

When the outer sleeve 26 was fixed, it was still used to protect the inner wall of the ceramic outer container.

In order to prevent the outer sleeve from compressing in the selected truncated cone configuration when the outer sleeve is not fixed to the outer container, or to limit it to defined values, the inner sleeve is provided with a toothing 25d over part of its circumference over its entire axial length or part of the axial length. which engages in a corresponding toothing 26d on the inner surface of the outer sleeve 26. The detailed drawing acc. FIG. 6 shows a state in which there has not yet been a locking engagement between the two toothings 25d and 26d, while in the main illustration according to FIG. 6 the locking engagement has already been achieved. When the outer sleeve 26 is pressed together, the wedge effect causes a relative movement between the outer sleeve 26 and the inner sleeve 25 in the direction of the arrow in the detailed illustration until the tooth flanks of the two locking teeth come into contact with one another.

In the embodiment according to FIGS. 7 and 8, an inner container 28 is used together with the outer container 24 according to FIG. 5, on the welded-on cover 29 of which an outwardly tapering frustoconical engagement surface is provided. The frictional engagement element 3o consists of each slotted sleeve part 31 and abutment ring 32, which has a conical engagement surface 32a which engages with the conical surface 29a when the device is assembled. In the stepped slot 31a of the sleeve part 31 extends with limiting play BS a limiter plate 33 fastened to the outer surface of the inner container 28, which limits the circumferential shortening of the sleeve part 31 to a predetermined value when the frictional engagement element is axially displaced, in which the free edges of the elongated plate 33 come into engagement with the gradations of the slot 31a.

FIGS. 9 and 10 show a further frictional engagement element 34 consisting of a sleeve part 35 and an annular abutment 36, which due to the frustoconical design of the outer surface 35b of the sleeve part is also progressive. The abutment provided with a continuous slot 36a is provided on its cylindrical outer surface with two ring grooves 36b and 36c, which have a different axial length. Two annular grooves 35d and 35e are formed on the cylindrical inner surface 35c at the same distance and with the same axial length. In the grooves are spring washers 37 and 37 'such that they engage in the assembled state of the frictional engagement element in the grooves 36b / 35d or 36c / 35e and thus lock the abutment ring 36 with the sleeve part 35 to introduce the dynamic forces into the sleeve part. The different axial width of the grooves and the spring washers serves to clearly assign the spring washers to the grooves.

In the embodiment according to FIGS. 11 and 12, an abutment ring 38 provided with a slot 38a is connected by means of bolts 39 to a slotted (4oa) sleeve part 4o. As can be seen from the detailed illustration, the bolts 39 pass through the associated bores 38b in order to permit the necessary thermal movements. The bolt head is supported on the abutment by a spring ring 41 and surrounded by a securing sleeve 42 in the bore 38b.

In the embodiment shown in FIGS. 13 and 14 for a friction locking element, a cover-like abutment 43 is screwed onto a sleeve part 44 provided with a slot part 44a by means of a thread engagement that is not free of play. A hexagonal detection opening 45 is provided in the cover-shaped abutment 43 for applying the rotary movement by means of a suitable tool.

In the embodiment according to FIGS. 15 and 16 for a frictional engagement element 46, the abutment 47 is positively connected to the sleeve part 48 via locking bolts 49, which are held in their locking position in recesses 51 in the sleeve part 46 by springs 50. When the abutment 47 is connected to the sleeve part, the locking bolts are retracted radially by a suitable tool against the bias of the spring 50 and the abutment 47 is lowered until the end faces of the locking bolts 49 face the openings 51. After releasing the locking bolts, the springs push them into the openings 51 until the locking members 49 come into contact with the safety bridges 52 connected to the abutment 47 (e.g. by welding).

FIGS. 17 and 18 show a particularly simple embodiment of the frictional engagement element 53, in which the sleeve part 54 and the abutment 55 have been produced in one piece. The slot 54a also passes through the abutment 55. In the abutment area, there are slots 54a on both sides Engagement bores 56 are provided, in which a clamping tool can engage. The tool clamps the frictional engagement element 53 while reducing the width of the slot 54a and then introduces it into an outer container (not shown).

FIGS. 19 and 20 show sleeve parts 57 and 58 which are provided with slot configurations which deviate from the straight-line slots used up to now. The sleeve part 57 is provided with a wave-like slot 57a of the configuration shown in FIG. 19, as in the case of an adapter sleeve. The abutment, not shown, must be designed so that when the abutment is attached to the sleeve, the preload impressed on the sleeve is not undesirably changed.

In the case of the sleeve part shown in FIG. 2o, the slot 58a runs first in the axial direction and then as a spiral slot around the sleeve, wherein it again changes into an axial direction of extension in the region of the insertion truncated cone.

FIGS. 21 and 22 show an embodiment of the device according to the invention in which no separate frictional engagement element is used, but the outer wall of an inner container 59 bears directly against the inner wall of an outer container 6o. The inner container 59 is a drawn container, which is closed by welding with a lid 61. The container 59 is provided with an inwardly extending and outwardly opening bead 62. The bead can be formed directly when the container 59 is manufactured or it is formed separately and then welded into the container. The bead 62 is so far described in its effect with the slots comparable embodiments. By means of a tool acting in the direction of the arrows in FIG. 22, the circumferential length of the inner container can be shortened and this can then be introduced into the outer container 60. After the tool has been removed, the container lies against the inner wall of the outer container under a predetermined preload. A few fuel rods 63 are indicated in the interior of the container, and the remaining free space is filled with a buffer material 64 before the inner container 59 is closed by the cover 61.

While the outer wall of the inner container and the inner wall of the outer container are shown in a straight cylindrical manner in FIGS. 21 and 22, frustoconical surfaces can also be used in such a configuration in order to make the frictional engagement progressive.

In the embodiment according to FIG. 23, the wall of the inner container 65 is provided with a multiplicity of beads 66 distributed uniformly around the circumference. The outer wall of the inner container 65 lies in the area between the beads on the inner wall of the outer container 67. The contact of the inner container with the outer container is not necessary for the function of the frictional engagement elements 68. Slotted tubular frictional engagement elements 68 are introduced into the beads 66 which extend perpendicular to the plane of the drawing in such a way that their slot 68a opens towards the bottom of the bead and the tubular jacket bears against the inner wall of the container 67. This results in a frictional engagement between the frictional engagement elements 68 on the one hand and the inner container 65 and the outer container 67 on the other hand. When the inner container is subjected to a thermal load, its greater thermal expansion than the outer container 67 can be absorbed by the container being deformed in the region of the beads, the frictional engagement element 68 being deformed at the same time.

A combination of the inner container according to FIGS. 21 and 22 with the frictional engagement element 68 is also conceivable. In this case, a frictional engagement element 68 which is introduced into the bead 62 of the inner container 59 acts like a spring element which tries to open the bead and thus increases the frictional force of the inner container.

In the embodiment according to FIG. 24, there is a straight-cylindrical inner container 69 in the outer container 67. In the annular space 70 remaining between the two containers, a plurality of friction-locking elements 71, also of tubular design, are introduced, which preferably have a C-shaped cross section, the two free ends 71a and 71b are rolled inwards, while the back 71c rests against the inner wall of the outer container 64.

Thermal expansion of the inner container 69 is absorbed by elastic deformation of the frictional engagement elements 71.

In the embodiment according to FIG. 25, wave-shaped frictional engagement elements 72 are introduced into the annular gap between the outer container 67 and the straight-cylindrical inner container 69, the peaks 72a abutting the inner wall of the outer container and the valleys 72b resting on the outer wall of the inner container 69. The frictional engagement elements 72 also deform elastically and thus exert a predetermined frictional engagement force. The elastic deformability also allows absorption of thermal loads.

In the embodiments according to FIGS. 23-25, either frictional engagement elements can be used, which extend essentially over the entire length of the inner container, or shorter frictional engagement elements are introduced one after the other and, in the case of FIGS. 24, 25, possibly offset.

In the embodiment according to FIGS. 26 and 27, the straight cylindrical inner container 69, which according to the section consists of a bottom 69a, a cover 69b and a jacket 69c welded to it, is held by means of eight comb-like frictional engagement elements 73. The frictional engagement elements 73 consist of a plurality of frictional engagement tongues 73a, which resiliently rest with their tip region 73a 'on the inner wall of the outer container 67. The base regions 73a ″ merge into a common comb back 73b, which bears against the outer wall of the inner container 69 and z. B. is welded to the outer wall before the inner container 69 is inserted into the outer container 67. The inner container equipped with the frictional engagement elements can be introduced into the outer container while rotating (counterclockwise according to FIG. 27). The outer surfaces of the friction-locking tongues then lie against the inner wall of the outer container under a preset prestress. The frictional engagement elements 73 are preferably made of spring steel. Of course, individual tongues 73a could also be connected separately to the outer wall of the inner container.

FIGS. 28 and 29 show a friction locking basket 74 which is suitable for holding an essentially straight-cylindrical inner container 69 in an outer container 69. Friction basket 74 is preferably made of spring steel and has punched out friction tongues 74a which serve for frictional engagement with the inner wall of the outer container. Between the external friction locking tongues 74a, retaining tongues 74b are formed, which can be in frictional engagement with the inner container or are connected to it by welding, gluing or the like. In order to evenly distribute the frictional engagement on the inner wall of the outer container, the tongues 74a are evenly distributed over the outer surface of the frictional engagement basket 74.

FIGS. 30 and 31 show a further friction locking basket 75, which is only provided with friction locking tongues 75a projecting outwards and can be connected on its inner surface to the inner container (not shown). The tip regions of the friction locking tongues 75a are bent radially inwards. As can be seen from the dotted representation in Fig. 31, there is also the possibility of cranking the tongue up to the point where its tip region lies against the inner container, so that the tongue and its tongue region lie on the inner container when a pretensioning and / or thermal deformation is applied can support.

After the friction-locking baskets have been fastened to the inner container, the inner container with the friction-locking basket can be introduced into the outer container in a simple manner by rotation. The axial length of the individual friction locking baskets can correspond to the required frictional engagement or several shorter baskets can be used. The baskets can also be provided with a longitudinal section running in the axial direction.

In the embodiment according to FIGS. 32 and 33, instead of a friction-locking sleeve, several more ring-shaped friction-locking sleeves 76 with slot 76a are provided, which bear with their straight-cylindrical outer surface 76b on the inner wall of the outer container 67. The rounded inner surface 76c of the individual friction ring 76 is in engagement with an annular groove 77a formed on an inner container 77, the shape of which is adapted to the inner surface 76c. Between the annular grooves 77a, the inner container 77 is provided with outwardly projecting annular beads 77b, so that, seen in the longitudinal direction of the inner container, annular grooves 77a and beads 77b alternate, that is to say the container jacket has a bellows-like jacket configuration, which can be seen in particular from the cutting area, the Bellows jacket with a Bottom and lid are welded. In this arrangement, the frictional engagement is evenly distributed on the inner wall of the outer container, while at the same time a good thermal adaptation and heat dissipation between the inner container and outer container is guaranteed and, if necessary, deviations from a straight cylindrical geometry in the diameter and / or cylinder axis of the inner and / or outer container are accommodated can be. The advantages mentioned above also result in particular from the arrangements according to FIGS. 26-31. Instead of the positive engagement (e.g. FIG. 1), the positive and non-positive engagement (e.g. FIG. 5), the embodiments according to FIGS. 23-31 show a purely non-positive engagement between the components without the desired external frictional engagement Outer container is at risk. If the frictional connection to the inner container is sufficient, this need not be held by special abutment sections.

As already mentioned, it is provided in a manner possible according to the invention that the frictional engagement is supported by an adhesive. The adhesive areas K must be applied so that the thermal behavior of the system is not hindered. For example, adhesive areas are shown in the figures as dash-dotted areas or lines.

As an adequately heat and corrosion-resistant adhesive that can be subjected to radioactive radiation, ceramic adhesives such as z. B. are sold by Aremco Products. Such adhesives are e.g. B. based on aluminum oxide, zirconium oxide and magnesium oxide and can be adjusted in terms of their tack properties on ceramics, graphite, quartz, boron nitride, silicon oxide and metals such as steel, aluminum and copper, ie just for connecting the frictional engagement elements with the outer container from one ceramic material or for connecting to the inner container made of metal or ceramic material.

If the adhesive points to the inner wall of the outer container are sufficiently stable and resilient, according to the invention there is no frictional connection. The outer wall of the inner container or the engagement element or elements used must then be designed for the formation of sufficiently large adhesive surfaces and in accordance with the desired thermal behavior of the system. If e.g. B. according to the embodiments. FIGS. 26-31, the tongues 73, 74a or 75a can be glued to the inner wall of the outer container with sufficient strength, the normal force they apply to the inner wall can be very small or zero. In the case of the tongues 73, when the two ends of the tongues are securely attached to the outer container or inner container under thermal load, the tongue is deformed between the ends.

In the embodiments according to FIGS. 24 and 25, a frictional engagement, i. H. a greater normal force can be dispensed with if the adhesive forces are sufficient. Other configurations for engagement elements for sole gluing are conceivable. However, the possibility of a frictional connection with supporting adhesive is particularly preferred.

As an example of the direct, sole adhesive engagement between the outer wall of the inner container and the inner wall of the outer container, reference should be made to a configuration comparable to the configuration according to FIG. 23. If the inner container 65 there rests in the areas between the beads 66 on the inner wall of the outer container 67 and is adequately bonded to it there and no engagement elements are arranged in the beads, good heat transfer to the outer container is ensured, and that with thermal stress Expected expansion of the inner container can be absorbed by deformation in the area of the beads.

Claims (19)

1. Device for storing radioactive material with an inner container receiving the material and an outer container surrounding the inner container made of a ceramic material, characterized in that the inner container (5; 22; 28; 59; 65; 69; 77) by large-scale intervention with the inner wall of the outer container (1; 15; 24; 6 ₀ ; 67) is held in this, the engagement being a sole frictional engagement, a frictional engagement supported by adhesive bonding or a sole adhesive bonding. 2. Device according to claim 1, characterized in that the outer wall of the inner container (59) is in direct engagement with the inner wall of the outer container (6 ₀ ). 3. Apparatus according to claim 1, characterized in that with the inner container (5; 22; 28; 65; 69; 77) at least one engagement element (11; 19; 23; 3 ₀ ; 34; 38.4 ₀ ; 43, 44; 47, 48; 54,55; 57; 58; 68; 71; 72; 73; 74; 75; 76) is in a non-positive and / or positive connection, the outer wall of which engages with the inner wall of the outer container (5; 22; 28; 67) is present. 4 .. Device according to claim 3, characterized in that a frictional engagement element from a slotted sleeve part (12; 2o; 25b, 26; 31; 35; 4o; 44; 48; 54; 57; 58) and one with the inner container in Connected abutment (13; 21; 25c; 32; 36; 38; 43; 47; 55) exists. 5. The device according to claim 4, characterized in that the sleeve part consists of at least two (25,26) nested sleeves, the slots (25a, 26a) are offset from one another in the circumferential direction. 12. The apparatus according to claim 2, characterized in that the wall of the inner container (59) is provided with at least one longitudinally extending bead (62) which opens to the outer surface. 13. The apparatus according to claim 1 or 3, characterized in that a plurality of engagement elements (11; 12; 19; 30; 68; 71; 72; 73; 74; 75; 76) with a substantially uniform distribution of their engagement surfaces over a large Hold the surface of the inner wall of the outer container (1; 15; 67) the inner container (5; 22; 67). 14. The apparatus according to claim 13, characterized in that the engaging elements (68; 71; 72; 76) are individually formed and are individually connected to the inner container. 15. The apparatus according to claim 13, characterized in that the engagement elements (71; 74a; 75a) at least in groups (71; 74; 75) are integrally formed with each other. 16. The device according to any one of claims 13-15., Characterized in that the engagement elements (71a; 74a; 75a) are tongue-like and resiliently resilient with their tip region (71a ') on the inner wall of the outer container (67) and over its base area is supported on the inner container (67). 17. The apparatus according to claim 15 or 16, characterized in that the engagement element tongues (74a; 75a) are punched out of a sleeve (74; 75) and are deformed outwards and that the sleeve (74; 75) with the inner container in Connection is established. 6. Apparatus according to claim 4 or 5, characterized in that the abutment overlaps an end face of the inner container. 7. Device according to one of claims 4-6, characterized in that the sleeve part (54) is integrally formed with the abutment (55). 8. Device according to one of claims 1-7, characterized in that in the region of the frictional engagement the inner wall of the outer container (15; 24) and the outer wall of the inner container (59b) or the frictional engagement element (19; 23 ; 3 ₀ ; 34) are designed frustoconical with adjustment of the truncated cone angle. 9. The device according to claim 8, characterized in that the inner wall of the outer container by means of two frictional engagement areas (17b, 17b) is frustoconical in such a way that the larger cross sections of the frustoconical engagement areas (17b, 17b) are adjacent to the container ends. lo. Device according to one of claims 4-9, characterized in that the slot is a straight longitudinal slot (12a), a substantially longitudinally extending wavy slot (57a) or a circumferential spiral slot (58a). 11. The device according to claim 4, characterized in that the support of the inner container (5; 22) on the or the associated abutments (13; 25c) is resilient (14; 25c). 18. Device according to one of claims 13-17., Characterized in that the engagement elements friction locking elements (11; 19; 23; 30; 34; 38; 40; 43; 44; 47; 48; 54; 55; 57; 58 ; 68; -71; 72; 73; 74; 75; 76;). 19. Device according to one of claims 1-18., Characterized in that the adhesive used for the adhesive is a ceramic adhesive.

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