JP4649580B2 - Complex waste confirmation system - Google Patents

Description

  The present invention determines whether or not the radioactive waste meets the disposal standards by irradiating the waste with various radiations to induce interaction, or by measuring the spontaneous radiation from the waste, The present invention relates to a composite waste confirmation system that can be verified reasonably and economically.

  It is necessary to satisfy a wide variety of conditions as a condition for accepting radioactive waste containing super uranium nuclides to the disposal site. Although there are some wastes that will be manufactured in the future, it is possible to judge whether some criteria are met based on the record of creation and the history before the creation of wastes. Some bodies do not have records or history based on disposal standards. In addition, for wastes to be manufactured in the future, as long as the verification method is based on the disposal of low-level radioactive waste at nuclear power plants that have already been implemented, not only the history of occurrence and treatment but also wastes. It is necessary to verify the radioactivity and the soundness of the solidified body at the time of unloading.

In order to solve these problems in recent years, in addition to the passive γ method that has already been put to practical use as a waste confirmation method, application of active neutron method, CT scan to waste confirmation, measurement of difficult-to-measure nuclides using photonuclear reaction Various nondestructive measurement methods have been studied energetically. For example, Patent Document 1 discloses an apparatus for measuring difficult-to-measure nuclides using photonuclear reaction. However, a common problem with these conventional measurement techniques is that the radiation generator and shielding structure are very expensive.
JP 2004-37106 A

  The problem to be solved by the present invention is to confirm whether or not the waste body meets the disposal standard by inducing various radiation interactions or measuring spontaneous radiation with one apparatus system. Various measurements for obtaining necessary information can be selectively executed, and waste component quality assurance can be performed reasonably and economically by using many components without waste.

The present invention relates to an electron beam accelerator for generating an electron beam, a radiation converter for generating radiation having a required characteristic by transmitting an electron beam output from the electron beam accelerator, and a sample stage on which a waste body as a measurement object is placed. And a waste body confirmation system comprising a radiation detection device for measuring a radiation type and intensity of radiation generated by transmission or reflection of radiation output from the radiation converter, wherein the electron beam accelerator comprises: , An energy variable type electron beam accelerator that generates an electron beam according to the X-ray energy required for measurement, and the radiation converter includes a low energy X-ray generation target , a high energy X-ray generation target, and a slice imaging collimator , neutron shield made of a neutron converter, the radiation detection device, at least X-ray CT detector Neutron detector includes a gamma ray detector, by their electron beam accelerator and radiation converter and the radiation detecting device, background measurement, passive neutron · gamma ray measurement, X-rays CT scan measurement, flame measured by light nuclear reaction species A single device system that can selectively measure measurement of neutrons, discriminating measurement of fissile and non-fissile materials using photoneutron mixing lines, and neutron activation analysis ,
In background measurement and passive neutron / γ-ray measurement, without using an electron beam accelerator and a radiation converter, a neutron detector and a γ-ray detector are used as a radiation detector.
In the X-ray CT scan measurement, the electron beam accelerator, a combination of a low-energy X-ray generation target and a slice imaging collimator as a radiation converter, and an X-ray CT detector as a radiation detection device are used.
In the measurement of difficult-to-measure nuclides by photonuclear reaction, the electron beam accelerator, a combination of a high-energy X-ray generation target and a neutron shield as a radiation converter, and a γ-ray detector as a radiation detector,
In the discrimination measurement of fissile materials and non-fissile materials using photoneutron mixed beam, the electron beam accelerator, the combination of high energy X-ray generation target and neutron converter as radiation converter, and neutron detector as radiation detector And
In the neutron activation analysis, the electron beam accelerator and the radiation are used such that the electron beam accelerator, a combination of a high energy X-ray generation target and a neutron converter as a radiation converter, and a γ-ray detector as a radiation detection device are used. The composite waste body confirmation system is characterized in that each device of the converter and each detector of the radiation detection device can be combined .

Here, the low energy X-ray generation target and the high energy X-ray generation target constituting the radiation converter can be exchanged by rotation or movement, and the slice imaging collimator, neutron shield and neutron converter can also be exchanged by rotation or movement. It is preferable that a combination of any one of the target for low-energy X-ray generation and the target for high-energy X-ray generation and any one of the slice imaging collimator, the neutron shield, and the neutron converter can be selectively formed . For example , a first converter that outputs a braking X-ray having a maximum energy of several MeV by a combination of a tungsten target for generating low energy X-rays having a thickness of about 1 mm to 2 mm and a collimator for slice imaging, and a thickness of about 5 mm A second converter that outputs a braking X-ray having a maximum energy of about 10 MeV by combining a tungsten target for generating energy X-rays and a Br-containing polyethylene neutron shield; a tungsten target for generating high energy X-rays having a thickness of about 5 mm; A third converter that outputs an optical neutron mixed line (mixed line of X-rays and neutron beams) can be formed by a combination of neutron converters.

  The sample stage on which the waste body to be measured is placed includes a turntable and an elevating mechanism, and it is preferable that the waste body can be rotated and moved vertically during measurement.

  In addition, the measurement area is configured to be shielded and divided in two measurement chambers adjacent to the passive measurement chamber and the active measurement chamber, and a moving rail is laid between the two measurement chambers and a shield door is provided between the two measurement chambers. Is placed on the moving rail so that it can be moved between the two measurement chambers, a plurality of γ-ray detectors are arranged in the passive measurement chamber, and a plurality of X-ray CT detectors are installed in the active measurement chamber. It is preferable that the neutron detector and the radiation converter are arranged, and an irradiation chamber containing the electron beam accelerator is attached to the active measurement chamber so that passive measurement and active measurement can be simultaneously performed on two waste bodies. .

  Since the composite waste body confirmation system according to the present invention can induce various radiation interactions or measure spontaneous radiation with one apparatus system, various systems for obtaining information necessary for confirmation of waste bodies can be obtained. Measurement can be selected and executed, many components can be used without waste, and each piece of measurement information can be linked to each other, so that the information required for waste quality assurance can be obtained collectively, rationally and economically. Can do.

  In particular, if the measurement area is divided into two measurement chambers adjacent to each other, the passive measurement chamber and the active measurement chamber, and the sample stage is configured to be movable between the measurement chambers, waste materials are simultaneously measured in the two measurement chambers. Since measurement is possible, the measurement time can be shortened and the background can be reduced.

  The composite waste confirmation system according to the present invention can perform a plurality of types of measurement in one or two measurement chambers as described above, so that a significant space saving can be achieved as compared with the conventional technique in which measurement is performed by a dedicated device. Can be achieved. At the same time, the device system is combined and integrated, and the radiation source (electron beam accelerator) and the like can be shared, and a great cost merit can be obtained. Further, by controlling the measurement procedure with the measurement control device, a plurality of required measurement categories can be selected, and the measurement efficiency can be improved by performing measurement according to the selection.

  FIG. 1 is a block diagram showing a configuration of a composite waste body confirmation system according to the present invention. This composite waste body confirmation system requires an energy variable electron beam accelerator 10 that generates an electron beam corresponding to the X-ray energy necessary for measurement and an electron beam output from the electron beam accelerator 10 to transmit the electron beam. A radiation converter 12 that generates characteristic radiation, a sample stage 16 on which a waste body 14 to be measured is placed, and a radiation species that is generated when the radiation output from the radiation converter 12 transmits or reflects through the waste body 14. And a radiation detection device 18 for measuring the intensity, and a measurement control device 20 for controlling each of these devices.

  The radiation converter 12 includes a low energy X-ray generation target 22, a high energy X-ray generation target 24, a slice imaging collimator 26, a neutron shield 28, and a neutron converter 30. As a result, three types of combinations of a low energy X-ray generation target 22 and a slice imaging collimator 26, a high energy X-ray generation target 24 and a neutron shield 28, and a high energy X-ray generation target 24 and a neutron converter 30 are provided. It can be formed, and they can be exchanged according to the measurement category. Although not shown, a structure that can be exchanged by using an elevating mechanism or a rotating mechanism is adopted. The radiation detector 18 includes an X-ray CT detector 32, a neutron detector 34, and a γ-ray detector 36.

  Here, the low energy X-ray generation target 22 is a tungsten plate having a thickness of about 1 mm to 2 mm, and the high energy X-ray generation target 24 is a tungsten plate having a thickness of about 5 mm. The neutron shield 28 is a polyethylene shield plate containing Br, and the neutron converter 30 is made of a material that easily causes a photonuclear reaction such as Be.

The X-ray CT detector 32 is a combination of a silicon semiconductor detector and a CCD camera, the neutron detector 34 is a combination of a He ₃ detector packed in polyethylene and a cadmium cut-off filter, and the γ-ray detector 36 is a NaI detector. And Ge detector.

  Furthermore, the sample stage 16 includes a turntable that rotates the waste body 14 to be measured and a lifting device that lifts and lowers the sample. The radiation detected by the radiation detection device 18 or transmitted through the waste body. In order to obtain information on the uneven distribution of radioactive substances or waste constituent substances, the function of rotating and raising / lowering is performed.

  The measurement control device 20 comprises a PC (personal computer), controls the processing procedures corresponding to the five types of measurements, controls the electron beam accelerator 10, controls the functions of the radioactive converter 12, and controls the equipment, Matrix correction (CT-Monte Carlo) is performed by simulation calculation such as the Monte Carlo method using various data collected by the radiation detection device 18 by performing position control of a certain waste body 14, selection of functions and equipment of the radiation detection device 18, and the like. Correction method), and the mutual link of the measurement results obtained in each measurement is performed.

  (1) Background measurement, (2) X-ray CT scan measurement, (3) Passive neutron / γ-ray measurement, (4) Measurement of difficult-to-measure nuclides by photonuclear reaction, (5) Light Discriminating measurement and neutron activation analysis of fissile material (Pu-239, U-235, etc.) and non-fissile material (U-238, Pu240, etc.) by neutron mixed line (mixed line of X-ray and neutron beam) Can be realized.

Table 1 shows a list of each component of the composite waste confirmation system.

FIG. 2 shows an example of a specific processing procedure of this composite waste body confirmation system.
Step S1: Prior to placing the waste on the sample stage prior to measurement, the background of γ-rays and neutrons in the measurement environment is measured.
Step S2: Using an electron beam accelerator, an X-ray having a maximum energy of about 1 MeV is generated by an electron beam having a relatively low energy, and an X-ray CT scan measurement is performed.
Step S3: Passive γ-rays and neutrons that passively detect radiation generated from the radionuclide using two types of detectors are measured.
Step S4: With the same electron beam accelerator, a powerful X-ray or neutron beam with a maximum energy of about 10 MeV is generated by a relatively high energy electron beam, and the waste body is irradiated with the active nuclear reaction induced thereby. Detect radiation.
Step S5: Perform discrimination measurement and neutron activation analysis of fissile material and non-fissile material using a photoneutron mixing line.

  From the information in step S1, harmful voids and density of the waste are examined to verify physical soundness such as compressive strength. From the information of step S1 and step S6, harmful substances (lead, aluminum, etc.) are quantified and the chemical soundness of harmful substances and the like is evaluated. Matrix information for performing correction calculation is obtained from the results of the measurements in steps S2 to S5. Matrix correction calculation is performed to evaluate the actual radionuclide amount from the 3D data of the matrix by CT scan and the measured radiation dose in order to obtain as much matrix inventory information as possible. In addition, the present confirmation system can omit an unnecessary step according to the type of waste body or can select and execute a step to be executed.

[First embodiment]
In the first embodiment, each device (radiation converter, sample stage, radiation detection apparatus) shown in FIG. 1 is arranged so that all the measurements described in Table 1 can be performed in one measurement chamber. The variable energy electron beam accelerator is attached to the measurement chamber so that the electron beam can be irradiated toward the radiation converter in the measurement chamber. Here, the low energy X-ray generation target and the high energy X-ray generation target constituting the radiation converter can be exchanged by rotation or movement, and the slice imaging collimator, neutron shield and neutron converter can also be exchanged by rotation or movement. And A plurality of neutron detectors and γ-ray detectors are equally arranged around and above and below the waste body. The X-ray CT detector can be installed at a position facing the radiation converter through the waste body. The X-ray CT detector is movable so that it can be retracted when not in use. Since this configuration requires only one measurement chamber, there is an advantage that space can be saved.

  Next, the combination, arrangement, and function of each device when performing each measurement described in Table 1 will be individually illustrated and described.

  FIG. 3 is an explanatory diagram showing the concept of passive neutron / γ-ray measurement. In this measurement, radiation from the waste body 14 is detected without using an electron beam accelerator (radiation source). The neutron detectors 34 and the γ-ray detectors 36 are evenly arranged around the waste body 14 and above and below (the top and bottom are not shown), and the radiation dose from the waste body 14 is measured. In this measurement, neutrons and γ rays emitted from γ-ray emitting nuclides such as Cs-137 and Co-60 and spontaneous fissile materials such as Pu-240 and Cm-244 are measured. Furthermore, since there is a tendency to underestimate due to the slowdown / absorption of neutrons by the matrix and attenuation of γ rays, correction is made using matrix information from X-ray CT scan measurement.

  FIG. 4 is an explanatory diagram showing the concept of X-ray CT scan measurement. The energy variable electron beam accelerator 10 generates an electron beam having energy corresponding to the necessary X-ray energy, and emits an electron beam of several MeV. The electron beam of several MeV is transmitted through the low energy X-ray generation target 26 made of tungsten having a thickness of several millimeters, and further desired braking X-rays are generated through the slice imaging collimator 26. As a result, X-rays for slice imaging that radiate in a plane necessary for X-ray CT scan measurement are generated. At this time, the low-energy X-ray generation target 26 made of tungsten has a structure that can be changed to an optimum thickness according to the incident electron beam energy. The X-ray for slice imaging transmitted through the waste body 14 is detected by the detector 32 for X-ray CT.

  Thus, in the X-ray CT scan measurement, the density distribution inside the waste is converted into 3D information using X-rays having a relatively low energy of about 1 MeV maximum energy induced by the electron beam accelerator 10. From this density distribution, physical soundness such as voids and compressive strength of the waste can be confirmed, and chemical soundness for judging the presence or absence of harmful substances such as heavy metal elements (lead, etc.) and aluminum can be confirmed. Further, matrix data used for correction calculation of each nondestructive measurement is obtained from this density distribution.

  FIG. 5 is an explanatory diagram showing the concept of measurement of difficult-to-measure nuclides by photonuclear reaction. The variable energy electron beam accelerator 10 generates an electron beam having energy corresponding to the necessary X-ray energy. This electron beam is transmitted through a high energy X-ray generation target 24 made of tungsten having a thickness of about 5 mm, converted to X-ray having a peak energy of several tens MeV, and further generates desired X-rays through a neutron shielding material 28. Let Thereby, high energy X-rays of several tens MeV can be generated. At this time, the tungsten high-energy X-ray generation target 24 is basically about 5 mm thick, but has a structure that can be changed to an optimum thickness according to the incident electron beam energy.

  In this measurement, the energy of the electron beam accelerator 10 is set to about 30 MeV, and X-rays having a maximum energy of about 10 Mev are generated by transmitting the high energy X-ray generation target 24. At this time, neutrons are also generated. However, since it interferes with measurement, it is necessary to devise measures to shield as much as possible. Therefore, a neutron shield 28 made of polyethylene containing Br is provided. By the way, when a certain atomic nucleus is irradiated with high energy X-rays exceeding its binding energy, a photonuclear reaction (γ, n) reaction occurs. Nuclei stripped of neutrons by this reaction may emit characteristic high-energy γ rays. For example, I-129 does not emit high-energy γ-rays that can be measured by passive γ-rays, but converts them to I-128 by (γ, n) reaction and detects γ-rays of about 443 keV generated from I-128. Thus, I-129 can be measured indirectly.

  Since this system is also equipped with a neutron detector 34, it is possible to know the number of reactions of (γ, n) reaction by measuring the number of neutrons. In addition, detection of γ-rays emitted from nuclides (I-128, etc.) produced by (γ, n) reaction of difficult-to-measure nuclides (I-129, etc.) 36 can be used. In addition to matrix correction for attenuation of γ rays emitted from nuclides, attenuation correction of incident X-rays that induce photonuclear reaction is necessary, and this is corrected by matrix information obtained by X-ray CT scan measurement.

  FIG. 6 shows the concept of discrimination measurement of fissile material (Pu-239, U-235, etc.) and non-fissile material (U-238, Pu240, etc.), and measurement of neutron activation analysis using a photoneutron mixing line. It is explanatory drawing. An electron beam corresponding to the required X-ray energy is generated by the energy variable electron beam accelerator 10, and the generated electron beam of several tens MeV is transmitted through the high energy X-ray generation target 24 made of tungsten having a thickness of about 5 mm. It is converted into X-rays having a peak energy of 10 MeV. This X-ray is incident on a neutron converter (photonuclear reaction target made of Be, Li, etc.) 30 to generate fast neutrons (neutron beams having a peak energy of several MeV). Thereby, a photoneutron mixed line (mixed line of an X-ray having a peak energy of several tens MeV and a neutron beam having a peak energy of several MeV) is generated. The high energy X-ray generation target 24 and the neutron converter 30 have a structure that can be changed to an optimum thickness by the incident electron beam energy.

When the waste 14 is irradiated with a photoneutron mixed beam, photons (X-rays) and neutrons induce fission of TRU nuclides in the waste, but measure the time change of fission neutrons (fast neutrons peaking at about 2 MeV) Then, as shown in FIG. 7, it can be roughly divided into four stages.
In the time zone (a) (0 to 630 μsec), prompt neutrons due to fission of both fissile material and non-fissile material by incident photons and fast neutrons are detected. Incident fast neutrons are decelerated to thermal neutrons by a moderator / reflector such as graphite.
In the time zone (b) (630 to 1350 μsec), it is captured by a fissionable material such as Pu-239, U-235, and a thermal fission reaction occurs, and prompt neutrons are generated. Here, fission by non-fissile material hardly occurs.
In the time zone (c) (1350 to 3200 μsec), both prompt neutrons and delayed neutrons are detected.
In the time zone (d) (> 3200 μsec), delayed neutrons in total fission are detected.
By the way, the count in (d) is tens of times higher for non-fissile material than for delayed neutrons caused by fissile material. Therefore, it is possible to discriminate and measure fissile material and non-fissile material from the ratio of the counts of (b) and (d). In this discrimination measurement, the amount of fissile material and non-fissile material is underestimated by the neutron absorption and moderating ability of the matrix. This is corrected using matrix information of X-ray CT scan measurement.

  Also, after irradiating neutrons, nuclides that have captured neutrons other than nuclear fission emit specific γ-rays. By measuring γ-rays from this (n, γ) reaction, nuclides such as chlorine and lead constituting harmful substances can be specified.

[Second Embodiment]
In the first embodiment, from the viewpoint of space saving, all the measurements described in Table 1 are performed in one measurement chamber. However, if there is enough space, the measurement time can be shortened and the background can be further reduced by separating the two measurement chambers. FIG. 9 shows a configuration of the entire apparatus when two measurement chambers are arranged in parallel.

  A region in which measurement is performed has a configuration in which two measurement chambers adjacent to the passive measurement chamber 50 and the active measurement chamber 52 are partitioned by a shielding wall 54. Then, a moving rail 56 is laid between the two measurement chambers, and a shielding door 58 is installed between the two measurement chambers, and the sample stage 16 is placed on the moving rail 56 so as to be movable between the two measurement chambers. The sample stage 16 includes a turntable and an elevating device, and a waste body 14 that is an object to be measured can be placed on the turntable. Further, shielding doors 58 are also installed on the side walls of the passive measurement chamber 50 and the active measurement chamber 52 so that the waste body 14 placed on the sample table 16 can be carried. A plurality of γ-ray detectors 36 are arranged in the passive measurement chamber 50 so as to surround the waste body 14. In the active measurement chamber 52, a plurality of neutron detectors 34 are arranged so as to surround the waste body 14, and the radiation converter 12 and the X-ray CT detector 32 are arranged. An irradiation chamber 60 that houses the electron beam accelerator 10 is attached to the active measurement chamber 52.

  In the active measurement chamber 52, a step of causing a (γ, n) reaction in measurement of a difficult-to-measure nuclide by a photonuclear reaction and a (n, γ) reaction in a neutron activation analysis by irradiating with a photoneutron mixed beam, Perform discriminating measurement of X-ray CT scan measurement and fissile material (Pu-239, U-235, etc.) and non-fissile material (U-238, Pu240, etc.) using photoneutron mixed rays that need to be measured while irradiating . In the passive measurement chamber 50, passive γ measurement is performed before radiation irradiation, and the γ rays of the waste after the (γ, n) reaction and (n, γ) reaction are measured in the active measurement chamber 52. By separating the two measurement chambers, the passive measurement chamber 50 and the active measurement chamber 52 in this way, it is possible to perform passive measurement of other waste bodies while irradiating a certain waste body in the active measurement chamber 52. Measurement time can be shortened. In addition, since the measurement chamber after irradiation with high energy radiation has a large background, this problem can be avoided by separating the measurement chamber into two.

  Next, the concept of divided measurement will be described with reference to FIG. When a collimator is attached to the detector to increase directivity, measurement can be performed by finely dividing the region to be measured, and the position of the radiation source can be specified. In FIG. 9, A represents a cross section in the xy direction (horizontal direction), and B represents a cross section in the xz direction (vertical direction). A plurality of collimator-equipped detectors 62 are arranged on the outer periphery of the waste body 14 or moved in the circumferential direction, measured at each position, and compared with each other, thereby determining the position of the radiation source 64 in the xy direction. Can be identified. Further, by arranging a plurality of collimator-equipped detectors 62 in the z direction, or moving in the vertical direction, measuring each slice, and comparing each, the position of the radiation source in the z direction can be specified.

  By the way, waste body constituent materials themselves often have a speed reduction / absorption capability. Whereas neutrons particularly interact with light elements such as hydrogen, X-ray CT scan measurement is unsuitable for identifying light elements. If it is difficult to quantify light elements by X-ray CT scan measurement, neutron CT scan measurement can also be used. In that case, a combination of a neutron scintillator made of 6LiF · ZnS (Ag) mixture or the like and a CCD camera may be used as the radiation detection apparatus.

1 is a block diagram of a composite waste body confirmation system according to the present invention. Explanatory drawing which shows the measurement procedure. Explanatory drawing of passive neutron and gamma ray measurement. Explanatory drawing of a X-ray CT scan measurement. Explanatory drawing of the measurement by a photonuclear reaction. Explanatory drawing of the discrimination measurement of a fissile material and a non-fissile material using a photoneutron mixing line. The graph which shows the time change of the fission neutron when a waste body is irradiated with a photoneutron mixing line. Explanatory drawing which shows the example of 2 measurement chamber structure. Explanatory drawing which shows the example of a division | segmentation measurement.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Electron beam accelerator 12 Radiation converter 14 Waste body 16 Sample stand 18 Radiation detection apparatus 20 Measurement control apparatus

Claims (5)

An electron beam accelerator that generates an electron beam; a radiation converter that generates radiation of a required characteristic by transmitting an electron beam output from the electron beam accelerator; a sample stage on which a waste body as a measurement object is placed; and the radiation In a waste body confirmation system comprising a radiation detection device that measures the line type and intensity of radiation generated by transmission or reflection of radiation output from a converter,
The electron beam accelerator is an energy variable electron beam accelerator that generates an electron beam according to the X-ray energy required for measurement, and the radiation converter includes a low energy X-ray generation target and a high energy X-ray generation target. , slice imaging collimator, neutron shield made of a neutron converter, the radiation detection device, at least X-ray CT detectors, neutron detectors, equipped with a γ-ray detector, and their electron beam accelerator and radiation converter Depending on the radiation detector, background measurement, passive neutron / γ-ray measurement, X-ray CT scan measurement, measurement of difficult-to-measure nuclides by photonuclear reaction, discrimination measurement of fissile / non-fissile material by photoneutron mixing line and neutron Configure a single system that can be selectively measured by activation analysis ,
In background measurement and passive neutron / γ-ray measurement, without using an electron beam accelerator and a radiation converter, a neutron detector and a γ-ray detector are used as a radiation detector.
In the X-ray CT scan measurement, the electron beam accelerator, a combination of a low-energy X-ray generation target and a slice imaging collimator as a radiation converter, and an X-ray CT detector as a radiation detection device are used.
In the measurement of difficult-to-measure nuclides by photonuclear reaction, the electron beam accelerator, a combination of a high-energy X-ray generation target and a neutron shield as a radiation converter, and a γ-ray detector as a radiation detector,
In the discrimination measurement of fissile materials and non-fissile materials using photoneutron mixed beam, the electron beam accelerator, the combination of high energy X-ray generation target and neutron converter as radiation converter, and neutron detector as radiation detector And
In the neutron activation analysis, the electron beam accelerator, a combination of a high energy X-ray generation target and a neutron converter as a radiation converter, and a γ-ray detector as a radiation detection device are used.
A combined waste body confirmation system characterized in that the electron beam accelerator, each device of the radiation converter, and each detector of the radiation detector can be combined . The low energy X-ray generation target and the high energy X-ray generation target constituting the radiation converter can be exchanged by rotation or movement, and the slice imaging collimator, the neutron shield and the neutron converter can also be exchanged by rotation or movement, As a result , a combination of any one of a target for low-energy X-ray generation and a target for high-energy X-ray generation , a slice imaging collimator, a neutron shield, and a neutron converter can be selectively formed. Item 2. The composite waste body confirmation system according to Item 1. The radiation converter includes a first converter that outputs a braking X-ray having a maximum energy of several MeV by a combination of a tungsten target for low energy X-ray generation having a thickness of 1 mm to 2 mm and a collimator for slice imaging, and a thickness of 5 m. a second converter that outputs a braking X-ray having a maximum energy of 10 MeV by combining a tungsten target for generating high-energy X-rays with m and a polyethylene neutron shield containing Br, and tungsten for generating high-energy X-rays with a thickness of 5 mm The composite waste body confirmation system according to claim 2, wherein a third converter that outputs a photoneutron mixing line can be formed by a combination of a target and a neutron converter. The composite type disposal according to any one of claims 1 to 3, wherein the sample stage on which the waste body to be measured is placed comprises a turntable and an elevating mechanism, and the waste body can be rotated and moved up and down during measurement. Body verification system. The measurement area is configured to be divided into two measurement chambers adjacent to the passive measurement chamber and the active measurement chamber, and a moving rail is installed between the two measurement chambers and a shield door is installed between the two measurement chambers. and, while movable between two measuring chambers placing the sample stage to the mobile rail, arranging a plurality of the γ-ray detector in the passive measurement chamber, wherein the X-ray CT detectors activate the measurement chamber and a plurality the neutron detector and the radiation converter is disposed of, and attached to the irradiation chamber which accommodates the electron beam accelerator to the active measuring chamber, and at the same time can be implemented with passive measurements and active measured for two waste The composite waste body confirmation system according to any one of claims 1 to 4.

Images