EP3559957B1

EP3559957B1 - Inner package of an overpack

Info

Publication number: EP3559957B1
Application number: EP17837964.0A
Authority: EP
Inventors: Daniel SHACKELL
Original assignee: Soletanche Freyssinet SA
Current assignee: Soletanche Freyssinet SA
Priority date: 2016-12-23
Filing date: 2017-12-21
Publication date: 2022-02-09
Anticipated expiration: 2037-12-21
Also published as: GB201622080D0; ES2912157T3; WO2018115356A2; LT3559957T; EP3559957A2; WO2018115356A3; CA3047850A1; SI3559957T1; PL3559957T3

Description

This invention relates to an inner package of an overpack for a storage container, in particular for the storage of radioactive material, e.g. for transportation.
Radioactive waste, following use in a nuclear facility, e.g. after processing, is stored in sealed storage containers, e.g. in 200 I drums. Such storage containers are intended to be suitable for long-term disposal and transportation, but are not intended to provide shielding from the ionising radiation emitted by the radioactive material.
When the storage containers are held in a storage facility, shielding for radioactive material may be provided by shielding walls, e.g. of concrete, that define a storage vault in which the storage containers may be placed for long term storage. This allows radioactive material to be stored safely, protected from and protecting the environment.
However, such storage facilities are often not located in the same place that the radioactive waste is produced and/or processed. Thus there is a need to transport the storage containers, containing radioactive waste, between locations, e.g. between processing and storage facilities. This allows radioactive material to be used in a nuclear facility, transported to a processing facility for processing and then to a storage facility for long term storage.
Overpacks provide shielding, containment and (e.g. impact) protection for the storage containers of radioactive material. Regulations, defined by the International Atomic Energy Agency, which cover the safe transport of radioactive material, define minimum standards (for the shielding, containment and (e.g. impact) protection) that such overpacks must satisfy. Thus overpacks will typically include an inner package including a barrel for receiving a storage container that provides containment for the radioactive waste and a structural cage for impact protection that surrounds the barrel, and an outer package having (e.g. steel) walls for shielding from the emission of ionising radiation, e.g. as shown in GB-A-2469392 .
A typical overpack is designed to carry four 200 I drums vertically, e.g. with a design that has a base plate onto which the drums are loaded, with an outer cage (e.g. including barrel covers and outer shielding walls) then being placed over the drums and bolted onto the base plate.
A processing technique for radioactive waste has been developed to produce compacted pucks of processed radioactive waste from 200 I drums of radioactive waste. These pucks have a wider diameter than the initial 200 I drums, such that they are too wide to fit back into the 200 I drums. However, it has been found that four of these compacted pucks fit into a 500 I drum for processed radioactive waste. This then presents a problem for transportation of the 500 I drums, as overpacks designed to receive four 200 I drums are not the right dimensions to receive and enclose a 500 I, owing to the 500 I drum being too tall and too wide (e.g. in diameter).
It is an aim of the present invention to provide an improved inner package of an overpack for a storage container for radioactive waste.
DE 100 20 009 A1 discloses a container unit consisting of a silo welded into a frame which is identical in terms of its structure with a frame of a conventional sea container suitable for ship, truck and rail transport. DE 29 44 734 A1 discloses a device for transportation of substances to be shielded from the environment comprising a cylindrical pressure vessel within an outer container.
The invention provides an inner package according to claim 1.
The invention also extends to an overpack according to claim 15.
Thus the present invention provides an overpack, and particularly an inner package of an overpack, with the inner package being for receipt of a 500 I drum for the storage of radioactive waste. The inner package has a cage that has a base portion, a top portion and side portions that extend between the base and top portions. The top portion has at least one lifting point for lifting the inner package, e.g. for suspending the inner package via the lifting point.
The cage surrounds a substantially cylindrical barrel that is able to receive a 500 I drum for the storage of radioactive waste. The barrel is structurally connected to the cage to hold the barrel within the cage, and the barrel is oriented in the cage such that the main cylindrical axis of the barrel lies substantially parallel with the top and base portions of the cage.
The overpack as a whole, as well as including an inner package, also includes an outer package surrounding the inner package.
It will be appreciated that the inner package of the present invention allows a 500 l drum to be contained (in a barrel) within an inner package, and thus within an overpack. This may allow a standard outer package (i.e. the shielding vessel that surrounds the cage of the inner package) of an overpack to be used with the inner package, e.g. without having to make the outer package taller and/or wider to accommodate 500 l drums (e.g. with the drums vertical in the same arrangement as a standard inner package).
The Applicant has appreciated that by arranging the barrel for receiving a 500 l drum horizontally in an inner package (when the inner package is in its normal orientation with the top portion facing upwards) this allows a 500 l drum to be placed into an inner package having similar dimensions to an inner package for holding four 200 l drums. Thus a standard outer package may be used with the inner package of the present invention, which allows 500 l drums of radioactive waste to be transported in overpacks while minimising the cost of such overpacks.
Being able to use a standard outer package with the inner package of the present invention also means that the combined overpack does not need to go through unnecessary testing and regulatory approval, which would be the case if a new outer package were to be designed for the transportation of 500 l drums.
The inner package of the present invention is suitable for receiving a 500 l drum. Such a 500 l drum is typically used for the storage of radioactive waste. Once the 500 l drum has been loaded into the inner package, and the inner package placed into an outer package to form an overpack, the overpack may be used to transport the 500 l drum of radioactive waste, e.g. between processing and storage sites.
The inner package may be configured in any suitable and desired way. In a preferred embodiment the inner package is arranged to provide structural protection for the 500 l drum, e.g. in the event of an impact against the overpack. Thus preferably the cage of the inner package is arranged to provide structural protection for the barrel. This helps to protect the structural integrity of the barrel (and thus the 500 l drum when stored inside), e.g. in the event of an impact.
The cage, which surrounds the barrel, and has base, top and side portions, may be arranged in any suitable and desired way, e.g. to provide structural protection for the barrel. In a preferred embodiment the cage (and preferably one or more of the base, top and side portions) comprises a braced structure. One or more of the base, top and side portions comprises a plurality of struts forming a lattice. The lattice may be open, e.g. with gaps between the lattice, or the inner package may comprise panels (either extending between the struts or across the whole of a portion). In a preferred embodiment the (e.g. lattice of the) top, bottom and/or side portions comprise cross bracing. This helps to strengthen the cage, thus improving the structural protection that the cage provides. Preferably the top portion and/or the base portion comprises a plurality of joists, e.g. having a (e.g. open) rectangular cross section.
In a preferred embodiment one or more (and preferably each) of the base, top and side portions are substantially planar. Thus preferably one or more (and preferably each of) the base, top and side portions comprise a planar lattice. In a preferred embodiment the inner package is substantially cuboid. Thus preferably the inner package comprises four side portions extending between the top and bottom portions. Preferably the top and bottom portions are substantially parallel to each other. Preferably the side portions are substantially perpendicular to the top and bottom portions. When there are four side portions, preferably a first pair of side portions are arranged opposite and substantially parallel to each other, and a second pair of side portions are arranged opposite and substantially parallel to each other and substantially perpendicular to the first pair of side portions. Preferably the base, top and side portions form the sides of a cuboid. Thus preferably one or more (and preferably each of) the base, top and side portions are substantially rectangular, e.g. square. One or more of the base, top and side portions (e.g. the base and top portions) may comprise chamfered corners. This may help to insert the inner package into an outer package.
In a preferred embodiment one or more of the top, bottom and side portions are integrally formed with each other. This helps to maximise the structural integrity of the cage. Preferably the top, bottom and three of the side portions are integrally formed with each other. Thus preferably the remaining side portion (e.g. lying substantially perpendicular to the main cylindrical axis of the barrel within the cage) is removably attached to the other portions of the cage. This removable side portion of the cage allows access to the barrel inside the cage so that a 500 l drum may be inserted into the barrel. Preferably the removable side portion of the cage is bolted onto the other portions of the cage, e.g. after a 500 l drum has been inserted into the barrel.
In order to help with the impact protection of the cage for the barrel inside, preferably the cage and/or the barrel comprises one or more shock absorbers. The shock absorbers may be provided in any suitable and desired way. In one embodiment the barrel comprises shock absorbers (e.g. stainless steel clad shock absorbing material) at each end of the barrel and/or around its circumference (e.g. along the length of the barrel). Thus preferably the barrel comprises shock absorbers between the main body and the cage, and also between the lid and the cage.
In a preferred embodiment one or more (and preferably each of) the base, top and side portions comprise shock absorbers. Preferably the shock absorbers comprise joists, struts and/or bracing that form at least part of the (e.g. lattice of the) base, top and/or side portions which are filled with a shock absorbing material (e.g. cork). Preferably the shock absorbers are located at (e.g. formed by joists, struts and/or bracing defining) the perimeter of one or more (and preferably each of) the base, top and side portions.
The top portion has at least one lifting point, which can be used to lift the inner package from above, e.g. by attaching a lifting device (e.g. a crane) to the lifting point, so that the inner package may be suspended. In a preferred embodiment the top portion comprises a plurality of (e.g. four) lifting points. Having multiple lifting points may give the inner package greater stability while being lifted and may enable it to be tilted. This is particularly useful as it may allow the inner package to be rotated, thus allowing a 500 l drum to be inserted into the barrel vertically, e.g. through one of the sides of the cage. When there are four lifting points, preferably these are arranged at the respective corners of the (e.g. rectangular) top portion.
In a preferred embodiment the base portion of the cage comprises forklift pockets. These pockets enable a forklift truck to insert its forks into the forklift pockets and to lift the inner package. Preferably the forklift pockets are provided in the joists of the base portion, e.g. when they have a hollow rectangular cross section.
The cage may be any suitable and desired dimensions for housing a 500 l drum in a barrel inside the cage. In a preferred embodiment the cage is substantially a cuboid having a height (the dimension between the top and base portions) that is less than the width and the depth (the dimensions of the top and base portions). Preferably the width and the depth are substantially equal to each other.
In one embodiment the inner package has an outer height (i.e. the height of the cage) of approximately 1.3 m. Preferably the inner package has an outer width and depth (i.e. the width and depth of the cage) of approximately 1.75 m.
The inner package comprises a substantially cylindrical barrel inside the cage. The barrel is suitable for receiving a 500 l drum for the storage of radioactive material. Thus preferably each dimension of the barrel is (e.g. slightly) larger than the corresponding dimension of a 500 l drum, i.e. the inside of the barrel forms a cavity that is able to receive a 500 l drum. A standard 500 l drum in the nuclear processing industry has a diameter of approximately 800 mm and a height of approximately 1230 mm. Thus preferably the barrel has a diameter of approximately 820 mm and a height of approximately 1250 mm, e.g. giving a nominal clearance of approximately 10 mm all around.
The barrel may be arranged in any suitable and desired way, e.g. to provide containment of radioactive material in a 500 l drum being stored inside the barrel.
Thus preferably the barrel is arranged to be sealed, e.g. after a 500 l drum has been placed inside the barrel.
Preferably the barrel comprises a main body and a lid (e.g. at one end of the cylindrical barrel). Preferably the lid is arranged to be sealed onto the main body to provide containment for radioactive material. The lid and the main body may be any suitable and desired shape to form the substantially cylindrical barrel. Preferably the main body of the barrel is substantially cylindrical having one (planar) end open. Preferably the lid of the barrel is substantially planar (e.g. circular), or comprises a substantially planar (e.g. circular) end and squat cylindrical sides (e.g. having a length (e.g. significantly) less than the length of the main body and/or less than the width of the lid (across the (e.g. diameter of the) planar end of the lid)). Thus the lid may comprise an (e.g. squat cylindrical) end cap.
Preferably the lid of the barrel is arranged adjacent (e.g. parallel with) one of the side portions of the cage, preferably the side that is removably attached to the other portions of the cage. This allows the 500 l drum to be inserted easily into the barrel and then the barrel lid closed.
The substantially cylindrical barrel (e.g. having a circular cross section) is oriented with its main cylindrical axis lying substantially parallel with the base portion and the top portion of the cage. Thus, when the cage is in its normal orientation (with the top portion uppermost), the barrel lies substantially horizontally (this contrasts with the inner package for four 200 l drums which are arranged vertically). Preferably the barrel is oriented in the cage such that its main cylindrical axis lies substantially parallel with a pair of opposite side portions of the cage and lies substantially perpendicular to the other pair of opposite side portions of the cage.
The barrel may be connected structurally to the cage to hold the barrel within the cage in any suitable and desired way. In one embodiment the (e.g. main body of the) barrel is connected to (e.g. integrally formed with) one of the side portions of the cage. Preferably the (e.g. planar, circular) end of the barrel is integrally formed with one of the side portions of the cage, e.g. the side portion opposite the side portion that is removably attached to the rest of the cage. The lid of the barrel may also be integrally formed with a side portion of the cage (e.g. the removably attached side portion), though in other embodiments the lid and its corresponding side portion may not be connected to each other. Instead, for example, the lid may be spaced from the corresponding side portion, e.g. by a few millimetres.
In addition to or instead of the barrel being connected to one or both of a pair of opposite side portions of the cage, the barrel may be connected to the top, the base and/or the other of the side portions of the cage as is suitable and desired. In a preferred embodiment the inner package comprises (e.g. cross-)bracing to connect the barrel to the cage. Preferably the (e.g. cross-)bracing suspends the barrel within the cage, e.g. so that the cylindrical sides of the barrel are not in contact with the respective side, top and bottom portions of the cage. This helps to protect the integrity of the barrel in an impact.
In a preferred embodiment the (e.g. cross-)bracing is connected to the barrel at four (e.g. equally spaced) points around the circumference of the barrel, e.g. at two sets of diametrically opposite points. Preferably the (e.g. cross-)bracing comprises four pairs of struts that are each connected between respective ends of the (e.g. main body of the) barrel and the respective base, top or side portion of the cage (preferably at the point where the base or top portion meets the respective side portion). Preferably each strut extends between an end of the (e.g. main body of the) barrel back along the length of the main body of the barrel. Thus preferably the struts in each pair of struts intersect each other to form a cross-brace lying in a plane.
In addition to or instead of the (e.g. cross-)bracing, the barrel may be connected to the top, the base and/or the side portions (e.g. the side portions that lie parallel to the cylindrical sides of the barrel) by one or more flanges, thus preferably the inner package comprises these one or more flanges. Preferably the flange(s) suspend the barrel within the cage, e.g. so that the cylindrical sides of the barrel are not in contact with the respective side, top and bottom portions of the cage. As with the bracing, this helps to protect the integrity of the barrel in an impact. In a preferred embodiment the one or more (e.g. two) flanges extend around the circumference of the barrel, and extend between the barrel and the top portion, the base portion and the side portions that lie parallel to the cylindrical sides of the barrel.
Preferably the flange(s) are arranged substantially parallel to the (e.g. planar) ends of the barrel and thus also to the respective pair of side portions of the cage. Thus preferably the flange(s) are arranged substantially perpendicular to the top, base and the other pair of side portions of the cage. Preferably the flange(s) are arranged towards a respective end of the (e.g. main body of the) barrel.
When the base portion of the cage comprises joists (e.g. that house forklift points), preferably the flanges (and thus the weight of the barrel and the 500 l drum when received inside the barrel) are supported by the joists.
The outer package of the overpack, which surrounds and receives the inner package, may be provided in any suitable and desired way. As described above, preferably the inner package is arranged such that it may be received by a standard outer package and thus not require a customised outer package to be specially designed to receive the inner package. For example, the outer package used may be the overpack described in the Applicant's UK patent GB-B- 2469392 or Nuvia Limited's Novapak .
Such outer packages comprise a box having walls made from steel plates that provide shielding for the radioactive material that is contained in the inner package.
An embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

Figure 1 shows a perspective view of an inner package of an overpack according to an embodiment of the present invention;
Figure 2 shows a cross-sectional view of the inner package shown in Figure 1; and
Figure 3 shows an outer package of an overpack for use with the inner package shown in Figures 1 and 2.

Radioactive waste, following use in a nuclear facility, e.g. after processing, may be stored in sealed 200 l drums. Such drums of radioactive waste may then be compacted into compressed pucks, four of which fit into a 500 l drum for processed radioactive waste. A 500 l drum can then be loaded into an overpack for transportation between processing and storage facilities, for example. An overpack provides shielding, containment and (e.g. impact) protection for the 500 l drum of radioactive material. An overpack typically includes an outer package having (e.g. steel) walls for shielding from the emission of ionising radiation, e.g. as shown in GB-A-2469392 , and within the outer package the overpack includes an inner package receiving the 500 l drum that provides containment and impact protection. An inner package according to an embodiment of the invention will now be described.
Figure 1 shows a perspective view of an inner package 1 of an overpack according to an embodiment of the present invention. The inner package 1 is designed to receive (for storage and transportation) a 500 l drum of radioactive material in a barrel 2 that is arranged horizontally in the inner package 1. The barrel 2 is substantially cylindrical with a main body 4 and a lid 6 that is removable for inserting the 500 l drum. The lid 6 of the barrel 2 is secured to the main body 4 by 20 bolts 8 to form a containment vessel, i.e. to contain any radioactive material if it happens to leak from the 500 l drum.
Surrounding the barrel 2 is an outer cage 10 that provides impact protection for the barrel 2 and thus the 500 l drum when stored therewithin. The outer cage 10 is substantially cuboid shaped with six substantially planar sides that are each formed by a lattice of stainless steel struts. The lattice 12 on the side of the outer cage 10 adjacent the lid 6 of the barrel 2 is removable to allow the lid 6 to be removed, with the lattice 12 being secured in position by 8 bolts 14.
The upper and the lower sides of the outer cage 10 are defined by respective rectangular joists 16, 18 with chamfered corners. These joists 16, 18 are made of stainless steel and filled with cork to provide shock absorption for impact protection. The upper side (top portion) of the outer cage 10 includes three shock-absorbing struts 20 that form a cross between the respective corners of the upper side. As with the joists 16, 18, the shock-absorbing struts 20 are made of stainless steel and filled with cork. Four lifting points 22 are provided on the struts 20 in the corners of the upper side of the outer cage 10 where the struts 20 meet the rectangular joist 16, to which, for example, hooks for lifting can be attached.
The lower side (bottom portion) of the outer cage 10 includes three shock-absorbing struts 24 that extend from one edge of the lower side to the other, parallel to each other. As with the other shock-absorbing struts, they are made of stainless steel and filled with cork. In addition, the two outer of the shock-absorbing struts 24 on the lower side of the outer cage 10 include fork lift pockets 26 for use in lifting the inner package 1.
The barrel 2 is secured within the outer cage 10 by two flanges 28 positioned towards the two ends of the main body 4 of the barrel 2, with the flanges 28 extending between the shock-absorbing struts 20 of the upper side of the outer cage 10 and the three shock-absorbing struts 24 of the lower side of the outer cage 10. Four cross-braces 30 also secure the barrel 2 in place (and provide impact protection) that extend between the sides of the barrel 2 and the rectangular joists 16, 18 of the upper and lower sides of the outer cage 10.
Figure 2 shows a vertical cross-sectional view of the inner package 1 shown in Figure 1. In this view a 500 l drum of radioactive material 32 is shown loaded inside the barrel 2 of the inner package 1. In addition to the external features of the inner package 1 that can be seen from Figure 1, Figure 2 shows that the lid 6 of the barrel 4 and the end of the main body 4 of the barrel contain respective steel clad shock-absorbing portions 34, 36.
Figure 3 shows an outer package 40 of an overpack for use with the inner package shown in Figures 1 and 2. The outer package 40 is a hollow cuboid having thick walls 42 made from cork clad with stainless steel sheet and a hinged door 44 that allows access to the inside of the outer package 40. The walls 42 of the outer package 40 provide shielding for the emission of particles from the radioactive decay of the material in the 500 l drum 32. The door 44 of the outer package 40 includes a latch 46 and 16 bolts 48 for securing the door 44 to the walls 42 of the outer package 40.
Together, the inner package 1 and the outer package 40 which form an overpack that can then be used to store and transport a 500 l drum of radioactive material.
Operation of the inner package 1 according to an embodiment of the invention will now be described with reference to Figures 1, 2 and 3.
At a nuclear processing facility, radioactive waste, after being processed is stored in sealed 200 l drums. Four of these 200 l drums are then compacted into compressed pucks, four of which are then loaded into a sealed 500 l drum 32. Using the inner package 1 shown in Figures 1 and 2, with the lid 6 of the barrel 2 and the lattice 12 on the side of the outer cage 10 adjacent the lid 6 of the barrel 2 being removed, the 500 l drum 32 is loaded into the main body 4 of the barrel 2. The lid 6 of the barrel 2 is attached to, and sealed on, the main body 4 of the barrel 2 by 20 bolts 8 to form a containment vessel. Following this the lattice 12 on the side of the outer cage 10 is secured onto the rest of the outer cage with 8 bolts 14.
The inner package 1 can then be loaded into the outer package 40, with the door 44 of the outer package 40 being secured in place with the latch 46 and the 16 bolts 48. The full overpack, containing the 500 l drum 32 surrounded by the inner package 1 and the outer package 40 is then able to be transported from the nuclear processing facility back to the donor site, e.g. the nuclear facility that produced the radioactive material.
The sealed barrel 2 provides containment for the radioactive material in the 500l drum 32, the outer package 40 provides shielding from the emission of ionising radiation emitted by the radioactive material in the 500l drum 32 and the inner package 1 provides impact protection for the radioactive material in the 500l drum 32. These features help the assembled overpack to satisfy the requirements of the regulations for such packages as defined by the International Atomic Energy Agency.
It can be seen from the above that in embodiments of the invention, the inner package of the present invention allows a 500 l drum to be contained in a barrel within an inner package, and thus within an overpack. This may allow a standard outer package of an overpack to be used with the inner package of the present invention, e.g. without having to make the outer package taller and/or wider to accommodate 500 l drums. Arranging the barrel for receiving a 500 l drum horizontally in an inner package allows a 500 l drum to be placed into an inner package having similar dimensions to an inner package for holding four 200 l drums. Thus a standard outer package may be used with the inner package of the present invention, which allows 500 l drums of radioactive waste to be transported in overpacks while minimising the cost of such overpacks.

Claims

An inner package (1) for placing into an outer package (40) to form an overpack for a 500 l drum for the storage of radioactive waste, the inner package (1) comprising:
a barrel (2) for receiving a 500 l drum for the storage of radioactive waste;

a cage (10) surrounding the barrel (2) and comprising a base portion, a top portion and side portions extending between the base portion and the top portion;

wherein the barrel (2) is substantially cylindrical and is oriented such that its main cylindrical axis lies substantially parallel with the base portion and the top portion of the cage (10);

the barrel (2) is structurally connected to the cage (10) to hold the barrel (2) within the cage (10); and

one of the side portions lying substantially perpendicular to the main cylindrical axis of the barrel (2) within the cage (1) is removably attached to the other portions of the cage (10), characterized in that the top portion has at least one lifting point (22) for lifting the inner package and in that one or more of the base portion, top portion and side portion comprises a plurality of struts forming a lattice (12).
The inner package (1) as claimed in claim 1, wherein the cage (10) comprises a braced structure; and/or wherein the top portion and/or the base portion comprises a plurality of joists (16, 18); and/or wherein one or more of the base, top and side portions are substantially planar; and/or wherein one or more of the top, bottom and side portions are integrally formed with each other and/or wherein the removable side portion of the cage is bolted onto the other portions of the cage (10).
The inner package (1) as claimed in any one of the preceding claims, wherein the cage (10) and/or the barrel (2) comprises one or more shock absorbers (20, 24, 34, 36); optionally wherein the barrel (2) comprises shock absorbers (34, 36) at each end of the barrel (2) and/or around its circumference; and further optionally wherein the barrel (2) comprises shock absorbers between the main body (4) and the cage (10), and between the lid (6) and the cage (10).
The inner package (1) as claimed in claim 3, wherein one or more the base, top and side portions comprise shock absorbers (20, 24).
The inner package (1) as claimed in claim 3 or 4, wherein the shock absorbers (20, 24, 34, 36) comprise joists, struts and/or bracing that form at least part of the base, top and/or side portions, and wherein the joists, struts and/or bracing are filled with a shock absorbing material; and/or wherein the shock absorbers (20, 24) are located at the perimeter of one or more of the base, top and side portions.
The inner package (1) as claimed in any one of the preceding claims, wherein the top portion comprises a plurality of lifting points (22); optionally wherein the lifting points (22) are arranged at the respective corners of the top portion.
The inner package (1) as claimed in any one of the preceding claims, wherein the base portion of the cage comprises forklift pockets (26).
The inner package (1) as claimed in any one of the preceding claims, wherein the barrel (2) is arranged to be sealed.
The inner package (1) as claimed in any one of the preceding claims, wherein the barrel (2) comprises a main body (4) and a lid (6).
The inner package (1) as claimed in claim 9, wherein the main body (4) of the barrel (2) is substantially cylindrical having one end open, and the lid (6) of the barrel (2) is substantially planar and/or comprises squat cylindrical sides; and/or wherein the lid (4) of the barrel (2) is arranged adjacent one of the side portions of the cage (10).
The inner package (1) as claimed in any one of the preceding claims, wherein the barrel (2) is oriented in the cage (10) such that its main cylindrical axis lies substantially parallel with a pair of opposite side portions of the cage (10) and lies substantially perpendicular to the other pair of opposite side portions of the cage (10); and/or wherein the barrel (2) is connected to one of the side portions of the cage (10).
The inner package (1) as claimed in any one of the preceding claims, wherein the inner package (1) comprises bracing (30) to connect the barrel (2) to the cage (10); optionally wherein the bracing (30) comprises four pairs of struts that are each connected between respective ends of the barrel (2) and the respective base, top or side portion of the cage (10).
The inner package (1) as claimed in any one of the preceding claims, wherein the barrel (2) is connected to the top, the base and/or the side portions by one or more flanges (28).
The inner package (1) as claimed in claim 12 or 13, wherein the one or more flanges (28) extend around the circumference of the barrel (2), and extend between the barrel (2) and the top portion, the base portion and the side portions that lie parallel to the cylindrical sides of the barrel (2).
An overpack for a 500 l drum for the storage of radioactive waste, the overpack comprising an inner package (1) as claimed in any one of the preceding claims, and an outer package (40) surrounding the inner package (1).