WO2006121377A1

WO2006121377A1 - A device for storage, transport or disposal of objets

Info

Publication number: WO2006121377A1
Application number: PCT/SE2005/000684
Authority: WO
Inventors: Jonny Olsson
Original assignee: Olcon Engineering Aktiebolag
Priority date: 2005-05-11
Filing date: 2005-05-11
Publication date: 2006-11-16
Also published as: US20090126555A1; CN100562704C; CN101223412A

Abstract

The invention relates to a device for storage, transport and disposal of objects such as suspected bombs and in particular for objects suspected of containing a so called dirty bomb. The inventive device comprises a shell having a sandwich design with an intermediate layer of lead and outer and inner steel layers. The invention also relates to a method of making such a device.

Description

A DEVICE FOR STORAGE, TRANPORT OR DISPOSAL OF OBJECTS

FIELD OF THE INVENTION The present invention relates to a device for storage, transport or disposal of objects such as suspected bombs, in particular objects suspected of containing radioactive substances or a combination of explosives and radioactive substances. The invention also relates to a method of making such a device and to a method for storage, transport or disposal of objects such as suspected bombs.

BACKGROUND OF THE INVENTION

Detonation chambers or blast chambers are used to destroy objects such as for example obsolete ammunition or explosives but also to destroy suspected terrorist bombs in a safe way. The blast chamber or detonation chamber typically comprises a shell that is designed to resist a detonation taking place inside the shell. In use, the object to be destroyed is placed inside the detonation chamber together with an explosive charge. The explosive charge is then caused to detonate such that the object inside the chamber is destroyed. An example of a detonation chamber is disclosed in, for example, US patent No. 4478126. Design of blast chambers has also been discussed in, for example, a journal article entitled "Design of Blast Chamber for Long-time use and Experimental Research" by Duan Zhoping and Tong Yi. This article was presented at the "Proceedings of the 2003 International Autumn Seminar on Propellants, Explosives and Pyrotechnics", Guilin, China.

In recent years, the risk that terrorists will seek to make a so called "dirty bomb" has been discussed. A so called "dirty bomb" is an object that contains an explosive charge and one or several radioactive substances placed near the explosive charge. If the device is detonated, the explosion will cause the radioactive substance to be scattered over a wide area. A large area can thus become polluted by radioactive substances such that the entire area becomes uninhabitable for a very long period. Additionally, the dirty bomb may cause illness and death to a large number of people who may be exposed to dangerous levels of radiation before they can be evacuated from the polluted area. Unlike an ordinary bomb, a dirty bomb cannot simply be destroyed by an explosive charge since the radioactive material in the bomb would still remain after the explosion. If a government agency responsible for security discovers an object that is suspected to be a dirty bomb, it is of vital importance that the suspected device can be removed from a place where the detonation of a dirty bomb could cause damage. It is moreover highly important that the suspected device can be moved to a place where detonation of a dirty bomb would cause the smallest possible damage or danger to human beings. Since it may be necessary to transport the object in question through populated areas, it is highly desirable that the transport can be carried out safely. It is an object of the present invention to provide a device suitable for receiving suspected dirty bombs and which can provide protection against radioactive radiation. It is also an object of the invention to provide a method of producing such a device. A further object of the invention is to provide a method for taking care of suspected dirty bombs.

DESCRIPTION OF THE INVENTION

The invention relates to a safety device comprising a shell that defines a chamber. The shell can be opened and closed such that objects can be placed inside the chamber. The shell is designed to be able to resist a detonation inside the shell from an explosive charge of up to at least 50O g of TNT. The shell is at least partially designed as a sandwich panel with an inner wall part made of steel, an outer wall part which is also made of steel and an intermediate wall part that is made of lead. The intermediate wall part is sandwiched between the inner and outer wall parts.

hi preferred embodiments of the invention, the shell is a spherical shell. However, other shapes can also be considered, for example cylindrical shells.

According to one embodiment of the invention, the intermediate wall part surrounds only a part of the chamber. In this embodiment, there are opposite sides of the shell that lack the intermediate wall part.

The thickness of the intermediate wall part is suitably 10 - 30 mm. The inner wall part may have a thickness of 20 - 40 mm while the outer wall part may have a thickness of 5 - 20 mm.

The invention also relates to a method for disposal of objects suspected of containing radioactive material. The method comprises providing a device having a chamber designed to resist a detonation inside the chamber from an explosive charge of up to at least 500 g of TNT, the chamber having a shell which is at least partially designed as a sandwich panel with an inner wall part made of steel, an outer wall part made of steel and an intermediate wall part made of lead, the intermediate wall part being sandwiched between the inner and outer wall parts. In the method, an object suspected of containing radioactive material is placed inside the chamber, the chamber is closed and locked and the device is subsequently transported to a place where detonation of a possible dirty bomb inside the chamber is unlikely to cause significant damage. For example, it can be placed in a mine shaft.

The suspected object may be tested for radioactivity before it is placed inside the chamber.

The invention also relates to a method of making a shell for the inventive device. The method of making the shell comprises the steps of providing a first semispherical shell having wall parts of steel that are spaced apart from each other to define a gap between the wall parts and pouring molten lead between the spaced apart wall parts to fill the gap with lead, thereby creating a sandwich panel.

Embodiments are possible where the entire semispherical shell is filled with lead but it is also possible that only a part of the semispherical shell is filled with lead.

Preferably, the method may further comprise repeating the same steps with a second semispherical shell and combining the two semispherical shells to create a spherical shell.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 is a schematic cross-sectional representation of a device according to the present invention.

Fig. 2 is a schematic drawing showing how the device may comprise two semispherical shells.

Fig. 3a and 3b show, from above, a detail of the device according to of Fig. 2. Fig. 4 is a schematic and cross sectional drawing of a part of the wall of the inventive device.

Fig. 5 is a cross sectional view showing in larger scale a detail from Fig. 4. Fig. 6 is a cross sectional and schematic representation of a step in a process for manufacturing a device according to the present invention Fig. 7 is a cross sectional view similar to Fig. 6 but showing a subsequent step in the manufacturing process.

Fig. 8 is a schematic representation of a possible further step during the process of disposing of a suspected obj ect.

Fig. 9 is a view similar to Fig. 1 but showing a somewhat different embodiment of the invention. DETAILED DESCRIPTION OF THE INVENTION

With reference to Fig. 1, the invention relates to a safety device 1 for storage, transport or disposal of an object suspected of containing a dirty bomb. The device 1 comprises a shell 2. In Fig. 1, the shell is showed placed on the ground and standing on legs 16. The shell 2 can be opened and closed such that objects 11, can be placed inside the chamber of the device 1. As indicated in Fig. 2, the shell 2 may be a spherical shell with two semispherical shells or shell halves 3, 4. The shell 2 can then be opened or closed by connecting or disconnecting the halves 3, 4 to or from each other. The shell is designed to be able to resist a detonation inside the shell 2 from an explosive charge of up to at least 500 grams of TNT (trinitrotoluene). It should be understood that, in most practical applications, the shell would be designed to resist detonations from charges of more than 500 grams of TNT. In some cases, it may be suitable to design the detonation chamber to be able to resist up to 1 kg of TNT, or 10 kilos of TNT or even more. The shell 2 is at least partially designed as a sandwich panel with an inner wall part 5 made of steel, an outer wall part which is also made of steel and an intermediate wall part 7 that is made of lead. The intermediate wall part 7 is sandwiched between the inner 5 and outer wall parts.

If a device is to be used for transport and/or disposal of objects such as suspected dirty bombs, it is desirable that it be capable of preventing radiation from leaking out. Lead which is used for the intermediate layer 7 is a material that is suitable for preventing radiation from escaping through the shell of the chamber. The reason for this is that lead is a heavy material with a density of about 11350 kilos per cubic metre. This makes lead very suitable for stopping both electromagnetic radiation and particle radiation that emanates from radioactive substances. However, lead is a material that is relatively soft and therefore not so suitable for a shell which is being used to contain detonations occurring inside the shell. Steel is a material which is far more suitable for this purpose due to the mechanical properties of steel, for example the elasticity and tensile strength of steel. Steel does not stop radiation as efficiently as lead and if steel is to be used instead of lead for stopping radiation, the steel layer would have to be thicker than a lead layer having the same radiation-stopping capacity. For these reasons, the inventor of the present invention has found that a device suitable for suspected dirty bombs should have a shell which is based on a combination of lead and steel. However, the inventor has also found that a steel shell which is simply covered by an outer layer of lead is unsuitable for a chamber where it must be anticipated that explosions may occur. The reason is that detonations taking place inside the steel shell may cause ruptures in the lead cladding and the lead layer is destroyed quite easily. The inventor has also found that a steel shell that simply uses an internal layer of lead is not a suitable design since fragments from explosions inside the shell will very easily cause damage to the soft lead layer. However, a shell which is based on a sandwich design with an intermediate layer of lead and inner and outer steel layers can both resist the destructive forces of a detonation taking place inside the chamber of the safety device 1 and effectively prevent radiation from leaking out.

The thickness of the intermediate layer may be, for example 10 - 30 mm. In many realistic embodiments, the thickness of the intermediate wall part 7 may be 25mm - 30 mm. The thickness of the inner wall parts 5 may be 20 - 40 mm. In realistic embodiments of the invention, the thickness of the outer wall part 6 or wall member 6 may be in the range of 5mm - 20 mm. The outer wall part 6 can be made less thick than the inner wall part 5.

The shell 2 is preferably a spherical shell 2 although it is possible to use shells having another shape, for example a cylindrical or cubical shape. The reason that a spherical shell is preferable is that a spherical shape is believed to be optimal for the ability of the shell 2 to resist a detonation inside the shell.

The material used for the inner and outer shells 5, 6 can be steel that has been cast or hot formed. If the shells 5, 6 are hot formed, the shells 5, 6 can be made of, for example, such steel plates that are sold by SSAB Oxelδsund AB, Sweden, under the name Weldox®.

The sandwich design is preferably used for the entire shell. However, it is also possible that only a part of the chamber uses the sandwich design. Figure 9 shows an embodiment where the intermediate wall part 7 surrounds only a part of the chamber. The part where the sandwich design is used is designated with the reference numeral 8 in Fig. 1. In the embodiment indicated in Fig.9, there are opposite sides 9, 10 of the shell 2 that lack the intermediate wall part 7. This means that radiation can leak out easier through the top part 9 and the bottom part 10 of the chamber of the safety device 1. However, the radiation leaking out from these parts will be directed upwards and downwards respectively. Hence, a person standing in front of the chamber will not be so much affected by radiation in these directions.

In Fig. 1 and Fig. 9, a device 13 for measuring radiation is schematically indicated as being placed adjacent the shell 2 and positioned outside a part 10 of the shell 2 where no intermediate lead layer is used. If a suspected dirty bomb has been placed inside the chamber, the measuring device 13 can be used to investigate whether radiation is leaking out from the chamber. It can then be a positive advantage that there is a part of the shell where it is easier for radiation to leak out.

As indicated in Fig. 2 - Fig. 5, the shell 2 may be provided with a locking ring 17 that can be used to lock the shell parts 3, 4 to each other. As indicated in Fig. 3 a and Fig. 3b, the locking ring 17 may have teeth 22 adapted to cooperate with teeth 23 in the shell halves 3, 4 when the locking ring is rotated. It should be understood that the teeth 23 may be a part of a ring-shaped element 18 connected to each shell half 3, 4. As indicated in Fig. 4, the teeth 23 in a shell part 3, 4 (or ring-shaped element 18) may form a T-profile where the locking ring 17 engages the shell parts 3, 4. As further indicated in Fig. 5, parts of the shell halves 3, 4 that cooperate with the locking ring 17 may be provided with ridges 20 that extend into grooves 19 in the locking ring 17. This design contributes to preventing radiation from leaking out. It should be understood that parts of the locking ring 17 may also be made of lead. As indicated in Fig. 4, the locking ring 17 may be surrounded by a ring-shaped outer cover 24 which is substantially made of lead. The outer cover 24 may also be a sandwich product with a thin inner layer of steel in the form of a metal sheet, an intermediate main layer of lead and a thin outer layer of sheet metal (preferably steel). The outer cover 24 may be connected to the locking ring 17, for example by screws, rivets or by welding. The outer cover 24 forms an additional radiation barrier that reduces leakage of radiation. However, it should be understood that the outer cover 24 is optional and that it is possible to envisage embodiments without such an outer cover.

As indicated symbolically in Fig. 4, the inventive device 1 may be provided with one or several seals 29 arranged to seal between the ring-shaped element 18 and the locking ring 17. This can contribute to prevent radioactive particles from leaking out. Furthermore, it can contribute to prevent harmful chemicals from leaking out in case a suspected device should contain harmful chemical substances, for example poison gas. The seal 29 may be an inflatable seal.

The invention also relates to the use of the inventive device. To dispose of a suspected object, the object 11 which is suspected of containing radioactive material is placed inside the chamber 1 as symbolically indicated in Fig. 1 and Fig. 2. The suspected object 11 may be placed in a basket 21 attached to a shell half 3 as schematically indicated in Fig. 2. Thereafter, the safety 1 is closed. The closing of the safety device 1 is schematically indicated in Fig. 2. In Fig. 2, an open position of the device 1 is indicated where the upper semispherical shell part 3 is in a lifted position which is indicated by a broken line and a closed position is indicated where the upper semispherical shell part is drawn with an unbroken line. It should be understood that after closing of the chamber, the shell halves 3, 4 are locked to each other, for example by the locking ring 17, such that a detonation inside the chamber will not cause the chamber to become open. When the chamber of the safety device has been closed and locked, the safety device 1 can be transported to a location that is deemed sufficiently safe.

As previously mentioned, measurement or test of radioactivity may be performed after the suspected device has been placed inside the chamber. If radiation is detected, it may be decided that the chamber shall remain closed. If no radiation is detected, it can be deemed safe to open the detonation chamber. It should of course be understood that the suspected object 11 can also be tested for radioactive activity already before it is placed inside the chamber of the safety device 1.

As schematically indicated in Fig. 8, disposal of suspected objects can also include filling the safety device 1 with concrete after a suspected object 11 has been placed in the device 1. In Fig. 8, the reference numeral 27 indicates a conduit through which concrete may enter the chamber 1. When the device 1 is filled with concrete, air may be evacuated through an air pipe 31.

The invention also relates to a method of making the shell 2 of the inventive device. A method of making the shell is schematically indicated in Fig. 6 and Fig. 7. The method comprises providing a first semispherical shell 3 having wall parts 5, 6 of steel that are spaced apart from each other to define a gap 14 between the wall parts 5, 6. As indicated in Fig. 6, the wall members 5, 6 or wall parts 5, 6 can be connected to/fastened to a ring-shaped element 18 which can have, for example, a T-profile or an H-profile adapted to interact with a locking ring 17 as described above with reference to Fig. 4 and Fig. 5. The wall members 5, 6 can be fastened to the ring-shaped element 18 by for example welding. In Fig. 6, the reference numeral 30 indicates a welding seam/welding seams. In this way, the wall parts 5, 6 can be held in a fixed position in relation to each other to define the gap 14. As indicated in Fig. 6, the outer wall part 6 may be provided with an opening 25 through which molten lead L can be poured into the gap 14 between the wall parts 5, 6 such that the gap 14 becomes filled with lead. Thereby, the intermediate layer of lead is created. Thereby, a sandwich panel is created. Possibly, only a part of the semispherical shell 3, 4 is filled with lead. However, in preferred embodiments of the invention, the gap 14 between the wall parts 5, 6 is completely filled with lead. As indicated symbolically in Fig. 7, the opening 25 can be closed by a plug 26 or some other closing element 26 when the gap 14 has been filled with lead. Alternatively, instead of closing the opening 25, a through-hole can be made in the shell such that a conduit 27 for concrete can be connected to the shell.

The method may further comprise providing a second semispherical shell 4 similar to the first semispherical shell and filling the gap with lead just as with the first semispherical shell. The semispherical shell parts or halves 3, 4 can then be combined with each other to create a spherical shell 2. The halves can be joined to each other by, for example, a locking ring 17 as indicated in Fig. 2.

It should be understood that while this description discloses a device, a method for making a shell and a method for disposal of objects, these are all different aspects of one and the same invention. The inventive method is thus suitable for making a shell which can be used for the inventive device. Similarly, the inventive method for taking care of objects is suitably carried out with a device according to the invention.

The inventive device entails the advantage that potentially harmful objects can be taken care of in such a way that reduces danger, even if explosive devices have been combined with radioactive substances. If an explosion takes place inside the inventive device, the device can resist the detonation and significantly reduce the amount of radiation if the explosive device is combined with radioactive substances. The sandwich design makes it more likely that the lead layer will be intact after a detonation inside the inventive device.

The inventive method for making a shell entails the advantage that a semispherical shell with a sandwich design can be manufactured in a practical and effective way.

Claims

1) A safety device (1) comprising a shell (2) that defines a chamber that can be opened and closed such that objects can be placed inside the chamber, the shell being designed to be able to resist a detonation inside the shell (2) from an explosive charge of up to at least 500 g of TNT, the shell (2) being at least partially designed as a sandwich panel with an inner wall part (5) made of steel, an outer wall part which is also made of steel and an intermediate wall part (7) that is made of lead, the intermediate wall part (7) being sandwiched between the inner (5) and outer wall parts.

2) A device according to claim 1, wherein the shell (2) is a spherical shell (2).

3) A device according to claim 2, wherein the intermediate wall part (7) surrounds only a part of the chamber and where opposite sides (9, 10) of the shell lack (2) the intermediate wall part (7).

4) A device according to claim 1, wherein the thickness of the intermediate wall part (7) is 10 mm - 30 mm, the inner wall part (5) is each 20mm - 40 mm thick and the outer wall part (6) is 5mm- 20mm thick.

5) A method for taking care of objects (11) suspected of containing radioactive material, the method comprising the steps of: a) providing a safety device (1) having a shell (2) that defines a chamber, the shell being designed to resist a detonation inside the chamber from an explosive charge of up to at least 500 g of TNT, the shell (2) further being at least partially designed as a sandwich panel with an inner wall part (5) made of steel, an outer wall part (6) made of steel and an intermediate wall part (7) made of lead, the intermediate wall (7) part being sandwiched between the inner (5) and outer wall parts, b) placing an object (11) suspected of containing radioactive material inside the chamber, c) closing the chamber (1) and d) locking the chamber such that an explosion inside the chamber will not cause the chamber to become open. 6) A method according to claim 5, wherein the suspected object is tested for radioactive activity before it is placed inside the chamber (1).

7) A method according to claim 5, wherein the chamber is filled with concrete after the chamber has been closed.

8) A method according to claim 5, wherein the safety device (1) is transported to a different location after the chamber has been closed and locked.

9) A method of making a shell (2) for a safety device, the method comprising the steps of a) providing a first semispherical shell (3) having wall parts (5, 6) of steel that are spaced apart from each other to define a gap (14) between the wall parts (5, 6) and b) pouring molten lead between the spaced apart wall parts to fill the gap (14) with lead, thereby creating a sandwich panel.

10) A method according to claim 9, wherein the method further comprises: a) providing a second semispherical shell (4) having wall parts (5, 6) of steel that are spaced apart from each other to define a gap between the wall parts (5,6), b) pouring molten lead between the spaced apart wall parts (5, 6) to fill the gap with lead, thereby creating a sandwich panel and c) combining the second semispherical shell (4) with the first semispherical shell (3) to create a spherical shell (2).

H)A method according to claim 9, wherein only a part of the semispherical shell (3, 4) is filled with lead.