EP0054944B1 - Storage equipment for radioactive material - Google Patents

Description

The invention relates to a device for storing radioactive material with an inner container holding the material and an outer container surrounding the inner container, in which the inner container is fixed therein by indirect engagement with the inner wall of the outer container.

From DE-A-27 26 335 such a device is known in which after the inner container has been placed on the bottom of the outer container, the remaining space is poured by means of a concrete or bitumen filling, so that after the filling of the inner container has hardened in the outer container indirect engagement with the outer wall is fixed.

From FR-A-24 54158 a device for the storage of radioactive material is known, in which the inner container is fixed axially with the help of holding-down devices in an outer container serving only for transport so that the inner container lid does not touch the lid of the outer container and in which the radial position of the inner container in the outer container is determined by a cross-sectional tapering of the interior of the outer container that runs toward the arc of the outer container. The cross-sectional tapering of the interior of the outer container is brought about by correspondingly wedge-shaped profiles on the outer wall of the inner container and the inner wall of the outer container. To improve the heat transfer from the outer wall of the inner container to the inner wall of the outer container, the wedge-shaped profiles preferably extend over the entire length of the inner container and fit into corresponding wedge-shaped profiles of the outer container, so that there is always metallic contact and thus metallic heat conduction between the inner and outer containers. The hold-down devices engage in recesses in the inner wall of the outer container.

Finally, from FR-A-23 75 696 a device for storing radioactive material with a plurality of inner containers holding the material and an outer container surrounding the inner container made of ceramic material is known, in one embodiment of which the inner container designed as a glass cylinder in the outer container in a powder or granular material are embedded, which has a heat-insulating effect, while in the other embodiment, the inner containers are set in closed storage spaces. Particularly when using a device with an outer container made of ceramic material, the outer container is subjected to heat as a result of the heat of decay released in the inner container. Since the materials used for the outer container and inner container mostly differ in their coefficient of thermal expansion, there is a risk that the radial and axial thermal stresses occurring in the known device will reach values that lead to damage or destruction of the outer container if the outer wall of the inner container is directly attached the inner wall of the outer container.

Furthermore, when using the device, there is a risk that acceleration forces are applied to the device. The outer container made of ceramic material has at least one insertion opening to be closed with a lid only after the inner container has been inserted. In the known device, there is a risk that when the device is used as intended, shock-like loads are applied to the bottom or the lid by the inner container, which lead to a brittle fracture of the ceramic outer container, which promotes voltage peaks. 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 in the preamble of claim 1, in which, when ceramic material is used for the outer container, ceramic loads are removed safely and free of notches in the inner wall of the outer container.

This object is achieved in that when using ceramic material for the outer container with the inner container is at least one frictional engagement element in a non-positive and / or positive connection, the outer wall of which rests in large-area frictional engagement with the inner wall of the outer container.

Accelerating forces acting on the inner container are thus transmitted uniformly and without a notch effect over a large area of the outer container.

The large-area frictional engagement can be achieved on the one hand over one or a few larger engagement surfaces or on the other hand over 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 a secure holding of the inner container is given. However, the individual smaller engagement surfaces must not be so small that notch effects can occur.

The frictional engagement is preferably a frictional engagement supported by adhesive.

In addition to the uniform introduction of the forces, good heat transfer from the inner container to the outer container is also achieved. In contrast to the device according to FR-A- 2454158 no hold-down is provided for the axial fixation of the inner container in the outer container.

In order to establish a non-positive connection between the frictional engagement element and the inner container, according to the invention, besides frictional engagement, welding, soldering, gluing is also understood.

The outer wall or the engagement surfaces of the frictional engagement element or the entire frictional engagement element are preferably made of a metallic material which ensures good heat transfer from the inner container to the outer container. The choice of material also determines the size of the frictional connection.

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 allowable values and to adjust the size of the normal forces acting on the outer container inner wall, the frictional engagement element or the frictional engagement elements can be prestressed. The frictional engagement element 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 preloadable frictional engagement 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.

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 invention 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 when 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 formed individually with the inner containers and can be connected individually with the inner containers, or the frictional engagement elements are at least in one piece with one another. Furthermore, if a plurality of frictional engagement elements are used, these are preferably tongue-shaped.

Inadmissible increases in the contact pressure of the frictional engagement element or elements on the inner wall of the ceramic outer container due to thermal stresses are avoided when using a sleeve-like frictional engagement element through the slot running in the axial direction, which enables a circumferential shortening of the frictional engagement element under thermal stress. 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. When using a slotted sleeve to build up the frictional engagement element, a frictional engagement element assembly with at least two sleeves inserted into one another can be provided in their place to increase the frictional forces, the slots of the two sleeve parts being offset with respect to one another 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 form the inner wall of the outer container like a truncated cone in the area of the frictional engagement and to adapt the outer wall of the frictional engagement element to this configuration. In the frustoconical design of the surfaces in frictional engagement, the normal forces and thus the frictional forces are progressively increased when the sleeve is displaced in the event of a load in the axial direction in that the prestressing force is increased by compressing the sleeve in accordance with the truncated cone angle. 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 by wedging the sleeve part of the frictional engagement element with the inner container is limited when the displacement force into the container is effective. When using two frictional engagement elements and a double truncated cone-like design of the inner wall of the outer container corresponding to the diabolo toy, an inadmissible displacement of the inner part is therefore prohibited. container and thus a load on the bottom and lid excluded.

The inner container can be be held in this frictional engagement of the frictional engagement element with the inner wall of the outer container; 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.

• Figur 1 einen Längsschnitt durch einen Außenbehälter und als Reibschlußelemente ausgebildete Eingriffselemente einer ersten Ausführungsform der Vorrichtung, wobei der Innenbehälter in Seitenansicht dargestellt ist,
• Figur 2 eine Prinzipdarstellung zur Erläuterung der Montagefolge bei Gebrauch der Vorrichtung gemäß Fig. 1,
• Figur 3 einen Längsschnitt längs der Linie lll-111 in Fig. 4 durch Außenbehälter und Reibschlußelemente einer zweiten Ausführungsform,
• Figur 4 einen Schnitt längs der Linie IV-IV in Fig. 3,
• Figur 5 ein entsprechender Schnitt durch eine dritte Ausführungsform,
• Figur 6 einen Schnitt längs der Linie VI-VI in Fig. 5 mit einer vergrößerten Detaildarstellung des Sperrklinkeneingriffes zwischen Innenhülse und Außenhülse,
• Figur 7 einen Schnitt längs der Linie VII-VII in Fig. 8 einer weiteren Ausführungsform,
• Figur 8 einen Schnitt längs der Linie VIII-VIII in Fig. 7,
• Figur 9 einen Schnitt durch eine weitere Ausführungsform eines Reibschlußelementes,
• Figur 10 einen Schnitt längs der Linie X-X in der Fig. 9,
• Figur 11 eine als Teilschnitt dargestellte Seitenansicht einer weiteren Ausführungsform eines Reibschlußelements mit einer vergrößerten Darstellung der Bolzenverbindung zwischen Hülsenteil und Widerlager,
• Figur 12 eine Aufsicht auf das Reibschlußelement gemäß Fig. 11,
• Figur 13 eine als Teilschnitt dargestellte Seitenansicht eines weiteren Reibschlußelements,
• Figur 14 eine Aufsicht auf das Reibschlußelement gemäß Fig. 13,
• Figur 15 einen Teilschnitt durch eine andere Ausführungsform des Reibschlußelementes,
• Figur 16 eine Aufsicht auf das Reibschlußelement gemäß Fig. 15,
• Figur 17 einen Teilschnitt durch eine andere Ausführungsform des Reibschlußelements,
• Figur 18 eine Aufsicht auf das Reibschlußelement,
• Figur 19 eine als Teilschnitt dargestellte Seitenansicht eines geschlitzten Hülsenteiles mit wellenartigem Schlitz,
• Figur 20 eine der Fig. 19 vergleichbare Darstellung eines weiteren Hülsenteils mit Spiralschlitz,
• Figur 21 einen Teillängsschnitt durch Innenbehälter und Außenbehälter mit in Sicken des Innenbehälters in Längsrichtung eingeschobenen geschlitzten Reibschlußrohren,
• Figur 22 eine Ausführungsform mit im wesentlichen geradzylindrischen Innenbehälter und Außenbehälter, wobei in einen zwischen den beiden Behältern verbleibenden Ringraum in gleichmäßiger Verteilung sich in axialer Richtung erstreckende Vorspannelemente eingeschoben sind,
• Figur 23 eine Ausführungsform, vergleichbar Ausführungsform Fig. 22, bei der in den verbleibenden Ringraum sich in Längsrichtung erstreckende und in Umfangsrichtung gewellte Reibschlußelemente eingeschoben sind,
• Figur 24 eine zum Teil als Schnitt dargestellte Seitenansicht einer weiteren Ausführungsform, wobei auf der Oberfläche des Innenbehälters kammartige Reibschlußelemente befestigt sind, die in Reibschluß an der Innenwandung des Innenbehälters anliegen,
• Figur 25 einen Schnitt längs der Linie XXV-XXV in Fig. 24,
• Figur 26 eine Seitenansicht mit nach außen vorstehenden Reibschlußzungen und nach innen vorstehenden Zungen zur Halterung des Reibschlußkorbes am Innenbehälter,
• Figur 27 einen Teilschnitt längs der Linie XXVII-XXVII in der Fig. 26,
• Figur 28 eine Seitenansicht einer weiteren Ausführungsform eines Reibschlußkorbes mit nach außen gebogenen Reibschlußzungen,
• Figur 29 einen Teilschnitt längs der Linie XXI-X-XXIX in der Fig. 28,
• Figur 30 eine zum Teil als Schnitt dargestellte Seitenansicht einer Ausführungsform der Vorrichtung mit Halterung eines balgenartigen Innenbehälters in einem im wesentlichen geradzylindrischen Außenbehälter,
• Figur 31 einen Schnitt längs der Linie XXXI-XXXI in der Fig. 30.

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,
• FIG. 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-111 in FIG. 4 through the outer container and frictional engagement elements of a second embodiment,
• FIG. 4 shows a section along the line IV-IV in FIG. 3,
• FIG. 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, FIG.
• FIG. 7 shows a section along the line VII-VII in FIG. 8 of a further embodiment,
• FIG. 8 shows a section along the line VIII-VIII in FIG. 7,
• FIG. 9 shows a section through a further embodiment of a frictional engagement element,
• FIG. 10 shows a section along the line XX in FIG. 9,
• FIG. 11 shows a side view, shown in partial section, of a further embodiment of a frictional engagement element with an enlarged illustration of the bolt connection between the sleeve part and the abutment,
• FIG. 12 shows a top view of the frictional engagement element according to FIG. 11,
• FIG. 13 shows a side view, shown in partial section, of a further frictional engagement element,
• FIG. 14 shows a top view of the frictional engagement element according to FIG. 13,
• FIG. 15 shows a partial section through another embodiment of the frictional engagement element,
• FIG. 16 shows a top view of the frictional engagement element according to FIG. 15,
• FIG. 17 shows a partial section through another embodiment of the frictional engagement element,
• FIG. 18 is a top view of the frictional engagement element,
• FIG. 19 shows a side view, shown in partial section, of a slotted sleeve part with a wave-like slot,
• FIG. 20 shows a representation comparable to FIG. 19 of a further sleeve part with a spiral slot,
• FIG. 21 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,
• FIG. 22 shows an embodiment with an essentially straight-cylindrical inner container and outer container, prestressing elements extending in the axial direction being inserted in a uniform distribution in an annular space remaining between the two containers,
• FIG. 23 shows an embodiment, comparable embodiment of FIG. 22, 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. 24 shows a side view of a further embodiment, shown partly as a section, comb-like frictional engagement elements being attached to the surface of the inner container, said frictional engagement elements being in frictional engagement with the inner wall of the inner container,
• FIG. 25 shows a section along the line XXV-XXV in FIG. 24,
• FIG. 26 shows a side view with outwardly projecting friction locking tongues and inwardly projecting tongues for holding the friction locking basket on the inner container,
• FIG. 27 shows a partial section along the line XXVII-XXVII in FIG. 26,
• FIG. 28 shows a side view of a further embodiment of a friction locking basket with friction locking tongues bent outwards,
• 29 shows a partial section along the line XXI-X-XXIX in FIG. 28,
• FIG. 30 shows a side view, partly in section, of an embodiment of the device with a bellows-like inner container being held in an essentially straight-cylindrical outer container,
• FIG. 31 shows a section along the line XXXI-XXXI in FIG. 30.

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. As connection technology is suitable for. B. 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 frictional engagement element, while the cover 8 is supported by a spring ring 14 on the sleeve end ring 13 of the upper frictional engagement element, the manipulation pin 10 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 2. The dimensions are chosen such 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 a green body processing.

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 serve 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 20 provided with a slot 20a and abutment sectors 21 which overlap the bottom or the cover 8 in the manner shown in FIGS. 3 and 4. The inner surface 20b of the sleeve part 20 is of straight cylindrical design, while the outer surface 20c is also frustoconical, adapting to the frustum angle of the frustoconical surface section 17b. In the assembled state, the inner surface 20b has play S from the outer surface of the inner container 5. In each abutment sector, a locking opening 21 is provided such 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 20c can be compared to the diabolo toy, in which a rotating body with a corresponding double-cone configuration is used. With an axial displacement forced by axial acceleration forces, e.g. B. from above in Fig. 3, the frictional engagement between the outer surface 20c of the upper frictional engagement element 19 and the associated surface section 17b of the outer container 15 is increased progressively, since the normal force acting on the surface section 17b by compressing the sleeve part 20 in accordance with the cone angle of the engaged located truncated cone surfaces is enlarged. The degree of compression of the The sleeve part is preferably limited by the predetermined slot width of the slot 20a or by prior contact of the inner surface 20b with the clearance of the play 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 compared 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 one inside the other so 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 20 of the frictional element 19 like. 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 25b bears on the inner surface of the frustoconical outer sleeve 26, which is also of 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 one another, the frictional forces can be increased compared to the use of only a single slotted sleeve. 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 2 6b 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 compression of the outer sleeve in the selected truncated cone configuration or to limit it to defined values when the outer sleeve is not fixed to the outer container, 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 gladly. 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 compressed, 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 30 consists in each case of a 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 clearance 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 steps 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 annular 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 friction element in the grooves 36b / 35d and 36c / 35e and thus the abutment ring 36 with the sleeve part 35 for introducing the dynamic forces into the sleeve part apply. 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 (40a) sleeve part 40. 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 in FIGS. 13 and 14 for a frictional engagement element, a cover-like abutment 43 is screwed onto a sleeve part 44 provided with a slot 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 the locking bolts have been released, the springs push them into the openings 51 until the locking members 49 come into contact with the safety bridges 52 connected (for example by welding) to the abutment 47.

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 penetrates the abutment 55. In the abutment area, engagement bores 56 are provided on both sides of the slot 54a, into 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 previous straight-line slots. 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. 20, 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.

In the embodiment according to FIG. 21, 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.

In the embodiment according to FIG. 22, 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 likewise tubular friction locking elements 71 are introduced, which preferably have a C-shaped cross section, the two free ends 71a and 71b are rolled inwards, while the back 71c bears 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. 23, wave-shaped frictional engagement elements 72 are introduced in 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. 21-23, 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 possibly offset in the case of FIGS. 22-23.

In the embodiment according to FIGS. 24 and 25, the straight-cylindrical inner container 69, which according to the section consists of a bottom 69a, a lid 69b and one with these welded jacket 69c is held by means of eight comb-like friction 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 back of the comb 73b, which abuts the outer wall of the inner container 69 and is, for example, welded to the outer wall before the inner container 69 is introduced into the outer container 67. The inner container equipped with the frictional engagement elements can be placed under The outer surfaces of the friction-locking tongues then lie against the inner wall of the outer container under preset prestress. The friction-locking elements 73 are preferably made of spring steel. Of course, individual tongues 73a could also be separated from one another with the outer wall of the inner container.

FIGS. 26 and 27 show a friction locking basket 74 which is suitable for holding an essentially straight cylindrical inner container 69 in an outer container 67. 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. 28 and 29 show a further friction locking basket 75, which is only provided with outwardly projecting friction locking tongues 75a 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. 29, there is also the possibility of cranking the tongue up to the point where its tip region rests against the inner container, so that the tongue is supported with its tongue region on the inner container when a pretension and / or thermal deformation is applied can.

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. 30 and 31, 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, alternate annular grooves 77a and beads 77b, i. that is, the container jacket has a bellows-like jacket configuration, which can be seen in particular from the cutting area, the bellows jacket being welded to a base and lid. 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 can be. The above-mentioned advantages result in particular from the arrangements according to FIGS. 24-29. Instead of the positive engagement (e.g. FIG. 1), the positive and non-positive engagement (e.g. FIG. 5), the embodiments according to FIGS. 21-29 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 preferably provided 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. available on the basis of aluminum oxide, zirconium oxide and magnesium oxide and can be adjusted with regard to their tack properties on ceramics, graphite, quartz, boron nitride, silicon oxide and metals such as steel, aluminum and copper, d. H. just for connecting the frictional engagement elements to the outer container made of a ceramic material or for connecting to the inner container made of metal or ceramic material.

Claims (16)

1. A device for storing radioactive material, comprising an inner container for receiving the . material and an outer container surrounding the inner container, the inner container being fixed in the outer container by indirect engagement with the inner wall of the latter, characterised in that, when a ceramic material is used for the outer container, at least one frictional connection element (11 ; 19 ; 23 ; 30 ; 34 ; 38 ; 40 ; 43 ; 44 ; 47 ; 48 ; 54 ; 55 ; 57 ; 58 ; 68 ; 71 ; 72 ; 73 ; 74 ; 75 ; 76) is in non-positive and/or positive connection with the inner container (5 ; 22 ; 28 ; 65 ; 69 ; 77), the outer wall of the frictional connection element bearing against the inner wall of the outer container in frictional connection over a large area.

2. A device according to claim 1, characterised in that the frictional connection is a frictional connection assisted by adhesive contact (K).

3. A device according to claim 1 or 2, characterised in that one frictional connection element consists of a slotted sleeve part (12 ; 20 ; 25b ; 26 ; 31 ; 35; 40; 44; 48 ; 54 ; 57 ; 58) and a support (13 ; 21 ; 25c ; 32 ; 36 ; 38 ; 43 ; 47 ; 55) which is in connection with the inner container.

4. A device according to claim 3, characterised in that the sleeve part consists of at least two telescoped sleeves (25, 26), the slots (25a, 26a) of which are mutually offset in the peripheral direction.

5. A device according to claim 3 or 4, characterised in that the support overlies one end face of the inner container.

6. A device according to any of claims 3 to 5, characterised in that the sleeve part (54) is formed integrally with the support (55).

7. A device according to any of claims 1 to 6, characterised in that, in the region of the frictional connection, the inner wall of the outer container (15 ; 24) and the outer wall of the frictional connection element (19 ; 23 ; 30 ; 34) which is in engagement with the former, are made in the shape of a truncated cone, with adjustment of the angle of the truncated cone.

8. A device according to claim 7, characterised in that the inner wall of the outer container is made in the form of a truncated cone by means of two regions (17b, 17b) of frictional engagement, in such a way that the larger cross-sections of the engagement regions (17b, 17b) in the shape of truncated cones are adjacent to the container ends.

9. A device according to any of claims 3 to 8, characterised in that the slot is a straight-line longitudinal slot (12a), a corrugated slot (57a) extending substantially in the longitudinal direction or a peripheral spiral slot (58a).

10. A device according to claim 3, characterised in that the inner container (5 ; 22) is supported on the associated abutment or abutments (13 ; 25c) in a resilient manner (14 ; 25c).

11. A device according to claim 1 or 2, characterised in that several frictional connection elements (11 ; 12 ; 19 ; 30 ; 68 ; 71 ; 72 ; 73 ; 74 ; 75 ; 76) retain the inner container (5 ; 22 ; 67) with substantially uniform distribution of their engagement surfaces across a large area of the inner wall of the outer container (1 ; 15 ; 67).

12. A device according to claim 11, characterised in that the frictional connection elements (68 ; 71 ; 72 ; 76) are formed individually and are individually connected to the inner container.

13. A device according to claim 11, characterised in that the frictional connection elements (71 ; 74a ; 75a) are designed to be integral with one another at least in groups (71 ; 74 ; 75).

14. A device according to any one of claims 11 to 13, characterised in that the frictional connection elements (73a ; 74a ; 75a) are designed in the form of tongues and bear with their tip region (73a') against the inner wall of the outer container (67) under elastic deformation and are supported by their root region on the inner container (69).

15. A device according to claim 13 or 14, characterised in that the frictional connection element tongues (74a ; 75a) are punched out of a sleeve (74 ; 75) and are outwardly deformed, and that the sleeve (74 ; 75) is in connection with the inner container.

16. A device according to any one of claims 2 to 15, characterised in that the adhesive used for the adhesive contact (K) is a ceramic adhesive.

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