JP2012122804A - Dangerous matter detecting system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a dangerous matter detecting system having a neutron radiating means suitable for installation in places where a luggage conveyor is installed and many people gather, such as terminal gates of airport or sea ports.SOLUTION: In a dangerous matter detecting system 1 having a conveyor 10 and a nuclear substance detecting device 30 installed midway on the conveyance route of the conveyor 10, the nuclear substance detecting device 30 has a neutron generator 31 that radially emits neutrons and a cylindrical side wall 32 arranged with some spacing from the neutron generator 31 in that emitting direction, the system further having a neutron intercepting wall 35 provided with doors 34a and 34b for opening and closing a luggage inlet 33a and a luggage outlet 33b, respectively, formed in the side wall 32 and a rotary floor 36 provided between the neutron generator 31 and the side wall 32 to be rotatable around the neutron generator 31 and supporting multiple units of luggage with spacing between each other in its rotating direction.

Description

  The present invention relates to a dangerous goods detection system.

  In recent years, homeland security has been actively studied in various countries as a countermeasure against terrorism. In Japan, various dangerous goods detection systems have been developed in order to suppress the taking-out / taking-in of dangerous goods at terminal gates in airports and ports. The following Patent Documents 1 to 5 disclose dangerous substance detection systems using X-ray irradiation means and neutron irradiation means in order to non-destructively inspect the contents of a load.

JP 2009-180563 A JP 2009-198469 A JP 2007-187467 A JP 2005-337764 A JP 2004-108994 A

By the way, when a dangerous substance detection system using neutron irradiation means is installed in a place where a conveyor for carrying a load is provided and a lot of people gather, such as a terminal gate in an airport or a port, there are the following problems.
At airports, etc., loads are continuously conveyed by the conveyor, so the majority of the area around the conveyor must be covered with thick neutron shielding walls. In addition, because the conveyor transport is continuous, the entrance / exit of the neutron shielding wall is always open, and when neutrons are irradiated to the load in this state, it is decelerated due to several scattering within the shielding wall. Even so, there is a risk of leakage from the opening through streaming. By the way, the energy of irradiated neutrons by DT reaction, which is usually used for detecting nuclear materials, is 14.1 MeV, and the energy of irradiated neutrons by DD reaction is 2.45 MeV, which is the neutron energy existing in ordinary reactors. Compared to this, the probability of leaking from the opening increases. Furthermore, if neutrons are irradiated for each load that is continuously conveyed by the conveyor, the number of neutron irradiations increases and the neutron level increases.

  The present invention has been made in view of the above problems, and has a danger of having a neutron irradiation means suitable for installation in a place where many people gather, such as an airport or a port terminal gate, where a conveyor for conveying loads is provided. The purpose is to provide an object detection system.

  In order to solve the above-described problems, the present invention provides a conveyor for transporting a load, a neutron detection device that is provided in the middle of a transport path in the conveyor and that detects a predetermined substance contained in the load by irradiating neutrons. The neutron detection device includes a neutron irradiation source that radiates the neutrons radially, and a cylindrical side wall that is spaced from the neutron irradiation source in the radiation direction. A neutron shielding wall having an opening and closing door for opening and closing the loading and unloading ports of the load formed on the side wall, and being rotatable about the neutron irradiation source between the neutron irradiation source and the side wall. A configuration is adopted in which a plurality of loads are provided in the direction of rotation and support the load at intervals.

  Further, in the present invention, a configuration is adopted in which an interval adjustment area is provided in the conveyor on the upstream side of the transport path with respect to the neutron detector so as to narrow the interval of the load being transported at a predetermined interval. To do.

  In the present invention, the conveyor on the downstream side of the transport path with respect to the neutron detector is provided with a second interval adjustment area for separating the transported load and returning the load to the predetermined interval. The configuration is adopted.

According to the present invention, a batch-type neutron detector is installed in the middle of the continuous conveyor conveyance, and the entrance / exit of the neutron shielding wall is completely closed by the neutron shielding door when neutron irradiation is performed. This makes it possible to completely prevent neutron streaming from the carry-in / out port of the neutron shielding wall. According to the present invention, since a plurality of loads can be arranged around the neutron irradiation source, a plurality of loads can be detected by a single neutron irradiation. As a result, the number of neutron irradiations can be reduced, the neutron level can be kept low, and the number of neutron irradiations can be reduced, so that the time loss required for the neutron irradiation time and the door opening / closing time of the neutron shielding wall can be reduced. Can be made equivalent to a continuous type. Furthermore, according to the present invention, by arranging a neutron shielding wall having a cylindrical side wall around the neutron irradiation source, the neutron shielding wall on the side where the neutron irradiation source of the conventional conveyor is provided (background side) The neutron detection space can be reduced and the floor area occupied can be kept small.
In addition, in the present invention, in order to further improve the processing capability by the batch method and make it equivalent to the continuous method, the neutrons are packed at a predetermined interval on the conveyor upstream of the neutron detector to reduce the load. It takes time to be carried into the detector, secures the detection time for the load that is currently receiving neutron detection, and is loaded into the neutron detector for the next load that receives neutron detection by closing the interval. Shorten the time until. After the neutron detection, the load can be sent out while maintaining the original interval by separating the intervals of the plurality of loads unloaded from the neutron detection device at the conveyor downstream of the neutron detection device. Thus, it is possible not to affect the subsequent inspection or loading / loading of the load.
Therefore, according to the present invention, it is possible to provide a dangerous goods detection system having a neutron irradiation means suitable for installation in a place where a large number of people gather, such as an airport or a port terminal gate.

It is a block diagram of the dangerous goods detection system in embodiment of this invention. It is a figure explaining the operation | movement for every predetermined division of the conveyor and operation | movement of a nuclear material detection apparatus in embodiment of this invention. It is a figure explaining operation | movement of the nuclear material detection apparatus in another embodiment of this invention. It is a figure explaining the state of the baggage in every predetermined division of a conveyor and nuclear material detection apparatus in another embodiment of this invention.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a configuration diagram of a dangerous goods detection system 1 according to an embodiment of the present invention.
The dangerous goods detection system 1 of the present embodiment is provided at a terminal gate of an airport, and contains dangerous goods (nuclear materials such as uranium and plutonium, radioactive materials such as cobalt) contained in the baggage (load) of a user boarding an aircraft. Is detected before being brought into the cabin.

  The dangerous goods detection system 1 includes a conveyor 10 that carries baggage, a γ-ray measuring device 20 that performs measurement using γ-rays on the baggage conveyed on the conveyor, and detection using neutrons on the baggage that is conveyed on the conveyor. Nuclear material detection device (neutron detection device) 30 to be performed, pseudo two-color X-ray DR device 40 that performs detection using X-rays on baggage transported by a conveyor, and control (not shown) that controls the operation of each component device And a device. In the dangerous substance detection system 1 of the present embodiment, a γ-ray measuring device 20, a nuclear material detection device 30, and a pseudo two-color X-ray DR device 40 are provided in this order along the conveyance path of the conveyor 10. ing.

The γ-ray measuring apparatus 20 has a γ-ray detector and detects γ-ray emission nuclides contained in baggage. The γ-ray measuring device 20 detects γ-rays emitted from baggage and detects γ-ray radioactive substances such as cobalt and cesium. The nuclear material detection device 30 is for detecting nuclear material such as uranium and plutonium by the active neutron method. Further, the nuclear material detection device 30 determines whether or not there is a neutron shielding material included in the baggage. The pseudo two-color X-ray DR device 40 performs high-precision DR (digital radiography) measurement using pseudo two-color X-rays and detects heavy metal substances such as gold, lead, uranium, and plutonium. Further, the pseudo two-color X-ray DR apparatus 40 determines the presence / absence of a γ-ray shield (such as lead) included in the baggage.
The dangerous substance detection system 1 of the present embodiment is configured to detect dangerous substances with high reliability by making use of the advantages of the above-described methods and compensating for each weak point.

Then, the characteristic structure in the nuclear material detection apparatus 30 of this embodiment is demonstrated.
The nuclear material detection device 30 includes a neutron generator (neutron irradiation source) 31 that radiates neutrons radially, and a neutron generator 31 and a cylindrical side wall 32 that are spaced apart in the radiation direction. The neutron generator 31 is rotated between the neutron generator 31 and the side wall 32 and the neutron shield wall 35 provided with opening / closing doors 34a and 34b for opening / closing the baggage entrance 33a and the exit 33b formed on the side wall 32. The rotating bed 36 is provided so as to be capable of supporting a plurality of baggage at intervals in the direction of rotation.

  The neutron generator 31 has a point line source installed at a height equivalent to the baggage to be supported by the rotating bed 36 in the center of the neutron shielding wall 35 as a line source. The radiation source of this embodiment is a neutron source by DT reaction, the neutron energy is a single energy of 14.1 MeV, and the radiation direction is omnidirectional. A plurality of neutron detectors such as He-3 (helium 3) scintillator (not shown) are provided on the inner peripheral surface of the side wall 32 of the neutron shielding wall 35, and the nuclear material detector 30 is generated by a DT reaction. The neutrons are irradiated to the baggage, causing a nuclear fission reaction in the nuclear material contained in the baggage and detecting the fission neutrons.

  The neutron shielding wall 35 is configured using SUS304 and polyethylene as a neutron shielding body. The neutron shielding wall 35 of the present embodiment has a layered structure in which SUS304 is disposed on the inner side and polyethylene is disposed on the outer side. In addition, SUS304 (not shown) is further provided outside the polyethylene. On the cylindrical side wall 32, a carry-in port 33a communicating with the upstream side of the conveyor 10 and a carry-out port 33b communicating with the downstream side of the conveyor 10 are formed. The carry-in port 33a can be opened and closed by an open / close door 34a that is slid and driven under the control of a control device (not shown). Similarly, the carry-out port 33b can be opened and closed by an open / close door 34b that is slid and driven under the control of a control device (not shown). The open / close doors 34 a and 34 b are configured to be slidable along the outer peripheral surface of the side wall 32.

  The rotating bed 36 is configured to rotate around the neutron generator 31 under the control of a control device (not shown). The rotary floor 36 of the present embodiment has a plurality of trays 37 (six in this embodiment at sixty-degree intervals) that support the baggage carried in from the carry-in port 33a with an interval in the rotational direction. The tray 37 is provided with a payout device (not shown) for paying out the baggage whose neutron detection is completed to the conveyor 10 on the downstream side from the carry-out port 33b.

  The conveyor 10 has an entrance portion 11a into which the baggage received at the check-in counter is placed and transported, and an entrance portion 11b into which the carry-on baggage with an alarm sounded at the security gate is placed and transported. The downstream sides of the inlet portions 11a and 11b have joined together, and the baggage first passes through the γ-ray measuring device 20 installed on the downstream side of the joining point. Baggage that has passed through the γ-ray measuring device 20 reaches the branching unit 12 via the nuclear material detection device 30 and the pseudo two-color X-ray DR device 40. The branching unit 12 is provided with a payout device (not shown). If any substance is detected in the γ-ray measuring device 20, the nuclear material detection device 30, or the pseudo two-color X-ray DR device 40, the baggage is detected. Is paid out on the route toward the unsealing inspection area 13 by a person. When it is confirmed by the inspection in the unsealing inspection area 13 that the baggage contains dangerous goods, the baggage is isolated and appropriate processing is performed. On the other hand, the baggage that has cleared the inspection in the opening inspection area 13 is returned to the downstream side of the branching section 12. The baggage that has not been paid out or returned is loaded into the aircraft from the exit 14a as check-in baggage or delivered to the passenger from the exit 14b as carry-on baggage. It becomes.

The conveyor 10 of this embodiment employs a roller conveyor system, and is configured such that the conveyance speed is adjusted for each predetermined section in the conveyance path under the control of a control device (not shown).
Hereinafter, with reference to FIG. 2, the operation | movement for every predetermined division of the conveyor 10 and operation | movement of the nuclear material detection apparatus 30 are demonstrated. In addition, the code | symbol M in FIG. 2 shows the baggage conveyed by a conveyor. In FIG. 2, the flow of the baggage M in the dangerous goods detection system 1 is shown over time at predetermined time intervals (steps S1 to S17). Moreover, in the following description, the conveyance section in the conveyor 10 is divided into a first area A, a second area B, a third area C, and a fourth area D (see FIGS. 1 and 2). There is.

As shown in FIG. 2, in the first area A of the conveyor 10, the baggage thrown in from the entrance part 11a or the entrance part 11b is transported at a predetermined speed with a predetermined interval. Then, the baggage M that has passed through the first area A is transported to the second area (interval adjustment area) B (step S1).
In the second area B of the conveyor 10, the interval of the baggage M conveyed from the first area A at a predetermined interval is adjusted by a control device (not shown). In the second area B of the conveyor 10, the conveyance speed of the roller conveyor is reduced or stopped to control the interval of the baggage M, and six pieces of baggage M are accumulated on the upstream side of the nuclear material detection device 30 ( Steps S2 to S6).

When six pieces of baggage M are collected in the second area B of the conveyor 10, the opening / closing door 34a of the nuclear material detection device 30 is opened, and the conveyance speed of the second area B is set to the conveyance of the first area A. Control is performed so as to be twice or more the speed, and at least two pieces of baggage M are stored in the nuclear material detection device 30 while one piece of baggage M is transported to the second area B (steps S7 to S9). . At this time, the rotating bed 36 of the nuclear material detection device 30 is also driven in synchronization with the speed change in the second area B of the conveyor 10, and the baggage M is received and rotated one by one on the tray 37. Are arranged around the neutron generator 31 at equal intervals.
When six pieces of baggage M are stored in the nuclear material detection device 30, the opening / closing doors 34a and 34b completely close the carry-in port 33a and the carry-out port 33b, and then the neutron is emitted from the neutron generator 31 by the DT reaction. Irradiate the azimuth and detect neutrons (step S10).

When the detection of neutrons in the nuclear material detection device 30 is completed, the open / close door 34b of the nuclear material detection device 30 is opened, and the rotary bed 36 is driven to rotate, so that all six pieces of baggage M supported by the tray 37 are inactivated. The payout device shown in the figure pays out to the third area C of the conveyor 10 on the downstream side of the nuclear material detection device 30 (step S11).
In the third area C of the conveyor 10, the baggage M paid out from the nuclear material detection device 30 is transported to a fourth area (second interval adjustment area) D (step S12). At this time, six pieces of baggage M are accumulated in the second area B on the upstream side of the nuclear material detection device 30. In the next step S13, two pieces of baggage M are provided in the same manner as in step S7 described above. Is stored in the nuclear material detection device 30.

In the 4th area D of the conveyor 10, the space | interval of the baggage M conveyed from the 3rd area C is adjusted. In the 4th area D of the conveyor 10, the conveyance speed of a roller conveyor is faster than the conveyance speed in the 3rd area C, is equivalent to the conveyance speed of the 1st area A, and is conveyed from the 3rd area C. The interval of the baggage M is separated and returned to the initial interval in the first area A (step S13).
In the fourth area D of the conveyor 10, the baggage M is conveyed toward the exit part 14a or the exit part 14b while performing the interval adjustment (steps S14 to S16). In the next step S <b> 17, all six pieces of baggage M in the third area C of the conveyor 10 are transported to the fourth area D. At the same time, the next six pieces of baggage M after neutron detection is paid out from the nuclear material detector 30. Then, the six pieces of baggage M paid out to the third area C of the conveyor 10 are adjusted to the initial interval and conveyed in the fourth area D of the conveyor 10 in the same manner as steps S13 to S17. .
As described above, the dangerous goods detection system 1 continues the inspection of the baggage M conveyed on the conveyor by repeating the steps described above. Then, when all the inspections of the baggage M are completed, the conveyor conveyance is stopped and all operations are ended.

  Therefore, according to the above-described embodiment, the conveyor 10 that transports the baggage M and the nuclear material detection device 30 that is provided in the middle of the transport path in the conveyor 10 and that detects the nuclear material contained in the baggage M by irradiating neutrons. The nuclear material detector 30 includes a neutron generator 31 that radiates the neutrons in a radial manner, and a neutron generator 31 and a cylinder arranged at intervals in the radiation direction. A neutron shielding wall 35 having an open / close door 34a, 34b that opens and closes a carry-in port 33a and a carry-out port 33b of the baggage M formed in the side wall 32, and a neutron generator 31 and the side wall 32. Rotation that is provided so as to be rotatable about the neutron generator 31 and supports a plurality of baggage M at intervals in the direction of rotation. 36, and a batch-type nuclear material detector 30 is installed in the middle of continuous conveyor conveyance, and when the neutron is irradiated to the carry-in port 33a / carry-out port 33b of the neutron shielding wall 35. It can be completely closed by the neutron shield doors 34a and 34b. This makes it possible to completely prevent neutron streaming from the carry-in port 33a / carry-out port 33b of the neutron shielding wall 35.

  Further, according to the present embodiment, since six pieces of baggage M can be arranged around the neutron generator 31, six pieces of baggage M can be detected by one neutron irradiation. As a result, the number of neutron irradiations is reduced to 1/6, the neutron level is kept low, and the number of neutron irradiations is reduced, so that the time loss required for the neutron irradiation time and the door opening / closing time of the neutron shielding wall 35 is reduced. The processing capacity can be made equal to that of the continuous type. Further, according to the present embodiment, the neutron generating wall 31 having the cylindrical side wall 32 around the neutron generating device 31 is disposed, whereby the neutron generating device 31 of the conventional conveyor 10 is provided (background side). ) Neutron shielding wall 35 can be reduced, the neutron detection space can be reduced, and the floor occupation area can be reduced to ½ or less compared to the conventional case.

In addition, in the present embodiment, for the purpose of further improving the processing capability by the batch method and making it equivalent to the continuous method, the baggage M conveyed at a predetermined interval on the conveyor 10 upstream from the nuclear material detection device 30. The baggage M that receives the neutron detection next by reducing the interval and securing the detection time of the baggage M that is currently receiving the neutron detection while gaining time until it is carried into the nuclear material detection device 30 by reducing the interval. The time until it is carried into the nuclear material detector 30 is shortened. After the detection of neutrons, the intervals between the plurality of baggage M carried out from the nuclear material detection device 30 are separated from each other on the conveyor 10 on the downstream side of the nuclear material detection device 30, thereby maintaining the original interval. Thus, the baggage M can be sent out, so that it does not affect the subsequent inspection, loading of the baggage M, delivery of the baggage M, and the like.
Further, in the dangerous goods detection system 1 of the present embodiment, from the time when six pieces of baggage M are collected on the upstream side of the nuclear material detection device 30 until the dispensing of the six items on the downstream side of the nuclear material detection device 30 is completed. By controlling this time to the time for six pieces of baggage M to pass through a certain point on the conveyor 10, the processing capability equivalent to that of the conventional continuous type can be achieved.

  Therefore, in the present embodiment, it is possible to provide the dangerous goods detection system 1 that is provided with the conveyor 10 for transporting the baggage M and suitable for installation in a place where many people gather at the terminal gate of the airport.

  As mentioned above, although preferred embodiment of this invention was described referring drawings, this invention is not limited to the said embodiment. Various shapes, combinations, and the like of the constituent members shown in the above-described embodiments are examples, and various modifications can be made based on design requirements and the like without departing from the gist of the present invention.

  For example, in the above-described embodiment, an example in which the dangerous goods detection system 1 of the present invention is installed at a terminal gate of an airport has been described. However, the present invention is not limited to this configuration, but a port, a station, a baseball field, a soccer field It can also be installed in places where people gather, such as event halls, theaters, museums, and art galleries.

Further, for example, the carry-in operation of the baggage M into the nuclear material detection device 30 and the operation for discharging the baggage M from the nuclear material device 30 may be performed as follows.
FIG. 3 is a diagram for explaining the operation of the nuclear material detection apparatus according to another embodiment of the present invention. FIG. 4 is a diagram for explaining the state of baggage in each predetermined section of the conveyor and in the nuclear material detection device according to another embodiment of the present invention. Note that the same hatched baggage M in FIGS. 3 and 4 corresponds.

  In the above embodiment, it has been described that when the inspection in the nuclear material detection device 30 is completed, all six pieces of the baggage M are paid out to the third area C. However, in another embodiment shown in FIG. 3 and FIG. A configuration is adopted in which the baggage M before inspection is carried in one by one while the baggage M is discharged one by one.

Specifically, as shown in FIG. 3 and FIG.
(1) After (14) described later, the rotating bed is rotated 1/6.
(2) Carry in one piece of baggage M before inspection and pay out one piece of baggage M after inspection.
(3) Rotate the rotating bed 1/6.
(4) Carry in one piece of baggage M before inspection and pay out one piece of baggage M after inspection.
(5) Rotate the rotating bed 1/6.
(6) Carry in one piece of baggage M before inspection and pay out one piece of baggage M after inspection.
(7) Rotate the rotating bed 1/6.
(8) Carry in one piece of baggage M before inspection and pay out one piece of baggage M after inspection.
(9) Rotate the rotating bed 1/6.
(10) Carry in one piece of baggage M before inspection and pay out one piece of baggage M after inspection.
(11) Rotate the rotating bed 1/6.
(12A) Carry one piece of baggage M before inspection.
(12B) Close the doorway.
(12C) Perform inspection.
(13) Open the doorway.
(14) Pay out one piece of baggage M after inspection.
Repeat the process.

If the steps (1) to (14) are set to be shorter than the time during which six pieces of baggage M are conveyed by the conveyor, the processing capability of the above-described embodiment can be made equivalent.
Specifically, t1 is the time to take in and out a piece of baggage, t2 is the time to turn the rotating bed 1/6, t3 is the time to close the doorway, t4 is the time to inspect the baggage M, t5 is the doorway to the baggage M If it is time to open, the total inspection sequence time T1 is
T1 = t1 + t2 + t3 + t4 + t5
Can be expressed as On the other hand, the inspection sequence total time T2 of the above-described embodiment is defined as an interval in which the baggage M flows at a normal speed t6.
T2 = t6 × 6
Can be expressed as Therefore, it is sufficient to set so that T2> T1.

  DESCRIPTION OF SYMBOLS 1 ... Dangerous goods detection system, 10 ... Conveyor, 30 ... Nuclear material detection apparatus (neutron detection apparatus), 31 ... Neutron generator (neutron irradiation source), 32 ... Side wall, 33a ... Carry-in port, 33b ... Carry-out port, 34a, 34b ... Opening / closing door, 35 ... Neutron shielding wall, 36 ... Revolving floor, B ... Second area (space adjustment area), D ... Fourth area (second space adjustment area), M ... Baggage (load)

Claims (3)

A dangerous substance detection system comprising: a conveyor that conveys a load; and a neutron detection device that is provided in the middle of a conveyance path in the conveyor and detects a predetermined substance contained in the load by irradiating neutrons,
The neutron detector is
A neutron irradiation source that radiates the neutrons radially;
A neutron shielding wall having an opening and closing door that opens and closes the loading and unloading ports of the load formed on the side wall, the neutron irradiation source and a cylindrical side wall arranged at intervals in the radiation direction;
A rotating bed provided between the neutron irradiation source and the side wall so as to be rotatable about the neutron irradiation source and supporting a plurality of the loads in the rotation direction at a distance from each other. Dangerous goods detection system.   The interval adjustment area which closes down the space | interval of the said load currently conveyed by the predetermined interval is provided in the said conveyor upstream of the said conveyance path | route from the said neutron detector. Dangerous goods detection system.   2. The second interval adjustment area is provided in the conveyor on the downstream side of the transport path from the neutron detector, and a second interval adjustment area is provided to return the transported load to the predetermined interval. 2. Dangerous goods detection system according to 2.

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