GB2115788A - Multisectional sleeve for protecting a fuel element transport container - Google Patents

Abstract

A multisectional sleeve (45) for protecting the central portion (2) of a fuel element transport container (2, 3, 4) consists of two telescoping sections (8, 9) which can be interlocked by means of hooking members (12). A seal is formed between the sections (8, 9) by inflating a tubular sealing member disposed in an annular flange (33) of the outer section (8). <IMAGE>

Description

SPECIFICATION Multisectional sleeve for protecting a fuel element transport container This invention relates to a multisectional sleeve for protecting a fuel element transport container.

In the case of the sleeve which is known from DE-A-29 12672, two end sections are combined with an intermediate section, by means of flanges, to form a rigid cylinder. Grooves with elastic seals are arranged in the flanges, at the joints. However, the length of the sleeve is not adjustable.

It is desirable to provide a sleeve whose length is adjustable so as to suit different transport containers.

According to the present invention, there is provided a multisectional sleeve for protecting a fuel element transport container, the sleeve comprising at least two overlapping and interiocking sections having therebetween a sealing means which is fixed to the outer section and which is adapted to bear against the inner section.

According to the present invention, the sleeve consists of two overlapping and interlocking sections having a common seal. The seal is secured to the outer section in such a way that it bears against the outside of the inner section. As a result, the interlocking sections are mutually displaceable so that the desired variability of length allows adjustment to suit different transport container lengths to be made.

Therefore, in spite of its rigid and therefore repeatedly usable design, the same sleeve can be used to protect practically all transport containers which are used in a nuclear power station.

The common seal is advantageously disposed in a flanged ring at the free end of the outer section. A flanged ring of this type, in addition to protecting the seal, allows for the possibility of providing connecting elements so that the seal can be deformed, for example pneumatically or hydraulically. Moreover, the flanged ring provides advantageous strengthening of both sections of the sleeve, which normally consist only of relatively thin sheets.

The flanged ring can advantageously have interlocking connecting members adapted in the lock onto the inner section. Most simply, such connecting members can be swivelling hooks.

They can cooperate with one or more projections so that, in the case of sleeves of different lengths, secure fastening is provided. Another possibility for adjustment to suit different transport container lengths is provided by the use of hooks of different lengths which are arranged such that they can be released and which therefore, after a short change-over period, provide a connection suited to the desired length of the sleeve.

In an advantageous embodiment of the invention, both sections, at the edges which are remote from the common seal, are provided with annular discs which project inwardly. By means of these annular discs, it is possible to make adjustments for different dimensions of width, hence, in the case of cylindrical transport containers, for different diameters of the transport container.

To illustrate the invention, an exemplary embodiment will now be described with reference to the drawings in which: Figure 1 is a vertical section showing the positioning of a sleeve of the invention, on a fuel element transport container; Figure 2 shows the sleeve in a position enclosing the transport container; and Figures 3, 4 and 5 show details of the sleeve, on d larger scale.

A transport container for transporting the fuel elements of a pressurized water or boiling water power reactor, is shown in Figure 1 by dot-anddash lines. It has a central region 2 having a cylindrical cross-section, of a diameter of 1.7 to 2.5 metres, provided with ribs (not shown in detail) for cooling. The container also has cylindrical rib-free ends 3 and 4 on which lifting lugs (not shown in detail) are provided. At least one of the ends 3 or 4 has a cover (not visible in the Figures) which can be detached for interior access. The total height of the transport container is approximately 5.4 metres, and its weight is approximately 100 tonnes.

In order to protect the ribbed surface in the central region 2 of the transport container, there is used a multisectional sleeve 5 for contamination protection, which is shown in Figure 1 in two positions. In one position, there is shown the way in which the sleeve 5 is positioned from above, by means of a four-armed starshaped carrying member 6, onto the transport container 1. The sleeve 5 consists of two sections 8 and 9 which are firstly telescoped together so that the axial length of the sleeve is as small as possible whereby the height which is required when the sleeve is being positioned is as small as possible. In this position, the two sections 8 and 9 are fixed to each other by connecting hooks 12. In the exemplary embodiment, the height of the sleeves 5 is 3.3 metres above the top edge 10 of the transport container 1.

After positioning the transport container 1, the carrying member 6 is connected by cables or chains 14 to a connecting member 1 5 on the outer section 8 of the sleeve 5. After the hook 12 has been released, the outer section 8 can then be lowered until its lower edge 1 6 extends over the lower end of the central region 2 of the transport cm trainer 1. In this position, the sleeve 5 is secured and sealed with respect to the transport container 1.

Figure 3 shows that the inner section 9 consists of a casing 17, having a cylindrical crosssection and a wall thickness of 6 to 8 mm, and an upper flange 18. An annular sealing flange 20 having a U-shaped cross-section is fixed to the flange 18. There is housed in the hollow space 21 of the sealing flange 20 a tubular seal 22 which can be expanded by means of compressed air, fed in through a connection 23, from the position which is drawn in solid lines into the position 22' which is drawn in dot-and-dash lines. In the latter, it presses tightly against the transport container 1 (part of which is shown in Figure 3 by the dotand-dash lines 24).

On the upper surface of the sealing flange 20, there are located brackets 25 in at least three positions distributed over the circumference of the flange 20. These stop brackets 25 have a hole 26 for the chains or cables 14. An arm 27 of the stop brackets 25 projects over the transport container 1 so that, by means of an adjusting screw 28, which is adjustably arranged in a tapped hole 29, it is possible to fix the sleeve 50 to the transport container 1.

Figure 4 shows that the approximately 5 mm annular space 30 between the two sections 8 and 9 of the sleeve 5 can be sealed by an inflateable seal 32. The seal 32 is located in a flanged ring 33 which is welded to the upper end of the casing 31 of the section 8 so that this casing 31, which has a wall thickness of 3 to 5 mm, is reinforced. In the flanged ring 33, the seal 32 is housed so that it is protected. It can be inflated by means of a compressed air connection 34, which is housed in a recess 35 of the annular flange 33 so that it is protected, the seal 32 is inflated to position 32', where it pressed against the outer surface of the inner section 9. A stop bracket 15, serving as the connecting member 1 5 mentioned above, is fixed to the annular flange 33. The brackets 15 has a hole 36 for attaching the cables of chains 14.

Figure 4 also shows that, at the lower end of the section 9, a ring 38 is welded to the casing 17 of the section 9, thereby providing reinforcement.

A stop 40, which is bolted onto the ring 38, serves as slider. It facilitates sliding between the sections 8 and 9 when these sections are moved relative to one another.

Figure 5 shows that the hooks 1 2 are pivotally mounted on the flanged ring 33 by means of a pivot 42. The hooks 12 engage boits 43, which are housed in recesses 44 of the section 9. The hooks 12 serve the purpose of interlocking the sections 8 and 9 so that the sleeve 5 can be braced as a whole to form a sealed sleeve around the transport container 1. This state is shown in Figure 2, where the sleeve is identified by reference numeral 45. The same hooks, however, also enable the telescoped sections 8 and 9 to be transported, as is shown in Figure 1. The pivot 42 is provided with a bolt with a nut so that it is easily removable. Therefore, the hooks 1 2 can be quickly changed for those of a different length, to produce a different length of sleeve 5.Moreover, the hook can be a hook which is adjustable in length, e.g. in the form of a turnbuckle with a central threaded member and a threaded sleeve which engages the central threaded member.

Figure 3 also shows that a connecting member 46 is welded into the casing 17 of the inner section 9. This member 46 serves for the supply of deionized water, i.e. chemically inactive water, for filling the space between the transport container 1 and the sleeve 45. The deionized water can flow out of an identical connecting member at the lower end of the outer section 8, for rinsing purposes.

The telescopic method of construction of the sleeve 5 enables its longitudinal dimension to be adjusted for different heights of the transport containers. Moreover, the sleeve also enables transport containers of different diameters (due, for example, to manufacturing tolerances) to be protected. For this purpose, in the arrangement represented in Figure 2, there is mounted, on the edge 1 6 of the section 8, an annular disc 47 which engages the portion 48 (see Figure 1) of the central section 2. An identical annular disc can also be provided at the other end of the sleeve 45 so that the holed obtained in Figure 3 by the adjusting screw 28 is produced.

Furthermore, the flanged ring 20 can also be changed if the expandable portion of the seal 22 cannot expand sufficiently to form a seal around the circumference of the transport container 1.

Claims (9)

Claims

1. A multisectional sleeve for protecting a fuel element transport container, the sleeve comprising at least two overlapping and interlocking sections having therebetween a sealing means which is fixed to the outer section and which is adapted to bear against the inner section.

2. A sleeve as claimed in claim 1, wherein either or both of the inner and outer sections are provided with a sealing means for forming a seal between the transport container and the respective section at the end thereof remote from the sealing means between the inner and outer sections, and/or with a fixing means for fixing the transport container to the respective section at the end thereof remote from the sealing means between the inner and outer sections.

3. A sleeve as claimed in claim 1 or 2, wherein the sealing means is disposed in a flanged ring at one end of the outer section.

4. A sleeve as claimed in claim 3, wherein the flanged ring has connecting members adapted to lock onto the inner section.

5. A sleeve as claimed in claim 4, wherein the connecting members are pivoting hooks.

6. A sleeve as claimed in claim 5, wherein the hooks are of adjustable length, and are releasable.

7. A sleeve as claimed in any of claims 1 to 6, wherein either or both of the inner and outer sections are provided with an inwardly-projecting annular disc at the end remote thereof from the sealing means between the inner and outer sections.

8. A sleeve as claimed in any of claims 1 to 7.

wherein the sealing means between the inner and outer sections comprises a tubular seal capable of being expanded pneumatically or hydraulically.

9. A sleeve as claimed in claim 1, substantially as hereinbefore described with reference to the accompanying drawings.