JP2016090483A - Detection device and method for metal oxide in waste liquid - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a detection device and method for a metal oxide in a waste water, capable of highly accurately detecting a total amount of the metal oxide in a high-level radioactive waste liquid.SOLUTION: The detection device is provided with: an airtight container 14 in which the high-level radioactive waste liquid is filled, the airtight container having a detection window 25 that allows transmission of an X-ray; an X-ray irradiator 15 that irradiates the high-level radioactive waste liquid with the X-ray through the detection window 25 of the airtight container 14; a semiconductor detector 16 that detects a fluorescent X-ray generated from the high-level radioactive waste liquid due to the irradiation of the X-ray; and a measurement device 17 that measure concentration of the metal oxide contained in the high-level radioactive waste liquid on the basis of a result of the detection by the semiconductor detector 16.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an apparatus and a method for detecting metal oxide in a waste liquid that measures the amount of metal oxide contained in a high-level waste liquid generated after shearing and dissolving the nuclear fuel in a nuclear fuel reprocessing step, for example. Is.

  Examples of nuclear reactors used in nuclear power plants include pressurized water reactors and boiling water reactors. In such a nuclear reactor, a large number of fuel assemblies (nuclear fuel) are arranged inside, and light water is used as a reactor coolant and a neutron moderator, and light water is heated by heat generated by nuclear fission. Electricity is generated by the heated light water (steam).

  When this nuclear fuel is used in a nuclear reactor, uranium 235 is fissioned and becomes a different material, for example, cesium, strontium, iodine, xenon, etc., so that it cannot be rated after a predetermined period. Therefore, it is necessary to remove the spent nuclear fuel from the nuclear reactor and reprocess it at the reprocessing facility. First, nuclear fuel that has been spent in the nuclear reactor is placed in a spent fuel transport container (cask), transported to a reprocessing facility, and stored while being cooled in a storage pool. Next, the spent nuclear fuel with reduced radioactivity is finely sheared, and a portion of the fuel is dissolved with nitric acid to separate it into uranium, plutonium and fission products. Then, the uranium solution and the plutonium solution are purified and denitrated to produce two types of products, uranium oxide and uranium / plutonium mixed oxide. On the other hand, the waste liquid containing fission products generated in the reprocessing process has a high level of radioactivity and becomes high-level radioactive waste. After cooling in the storage tank and solidifying with glass material, it fills the canister. To be stored.

  Examples of such a high-level waste liquid treatment apparatus include those described in the following patent documents.

Japanese Patent Publication No. 08-000193 Japanese Patent Publication No. 06-102148 Japanese Patent No. 4690623

  As described above, the high-level radioactive liquid waste containing fission products generated in the reprocessing step is solidified by the glass material, stabilized and stored. In this case, the amount of the glass material supplied to the high-level radioactive liquid waste is set according to the total amount of metal oxides in the high-level radioactive liquid waste. Therefore, it is necessary to grasp the total amount of metal oxide in the high-level radioactive liquid waste by chemical analysis in advance. Generally, when grasping the total amount of metal oxides in the high-level radioactive liquid waste, the high-level radioactive liquid waste is forcibly heated to form a solid, and the mass of the solid sample is measured. However, depending on the components of the high-level radioactive liquid waste, the metal oxide form changes, or the moisture content of the solid sample changes depending on the surrounding environment. It was difficult to accurately grasp the total amount of

  The present invention solves the above-described problems, and an object of the present invention is to provide an apparatus and a method for detecting metal oxide in waste liquid that can accurately detect the total amount of metal oxide in high-level radioactive waste liquid. And

  In order to achieve the above object, the apparatus for detecting a metal oxide in a waste liquid according to the present invention includes a sealed container having a detection window filled with the waste liquid and capable of transmitting radiation, and the waste liquid is irradiated with radiation through the detection window of the sealed container. A radiation irradiator that irradiates the radiation, a detector that detects radiation generated from the waste liquid by radiation irradiation, and a measurement device that measures the concentration of the metal oxide contained in the waste liquid based on the detection result of the detector. It is characterized by having.

  Therefore, when the radiation irradiator irradiates the waste liquid with radiation through the detection window of the sealed container, the detector detects the radiation generated from the waste liquid by irradiation of the radiation and outputs it to the measuring device. Based on the detection result, the concentration of the metal oxide contained in the waste liquid is measured. As a result, the total amount of metal oxide in the high level radioactive liquid waste can be detected with high accuracy.

  In the apparatus for detecting a metal oxide in a waste liquid according to the present invention, the sealed container is disposed so that the detection window is positioned at a lower portion in the vertical direction, and the radiation irradiator is disposed from below the sealed container. It is characterized by emitting radiation toward

  Therefore, since the solid substance containing the metal oxide in the sealed container is precipitated in the solution, it is collected on the detection window side located at the lower part, and the radiation irradiator emits radiation toward the detection window from below. Thus, it is possible to appropriately irradiate the solid matter containing the metal oxide with radiation.

  In the apparatus for detecting a metal oxide in a waste liquid according to the present invention, the closed container is provided with an opening for filling the waste liquid, and a polyethylene sheet is attached to the opening so as to be closed. A detection window is formed.

  Therefore, by providing an opening in the sealed container, waste liquid can be easily filled in the sealed container, and by attaching a polyethylene sheet to this opening, the opening can be easily closed to detect the detection window. Can be formed, and the structure can be simplified.

  In the apparatus for detecting a metal oxide in a waste liquid according to the present invention, the measurement apparatus calculates the concentration of the metal oxide contained in the waste liquid based on the detected radiation and the intensity ratio of the radiation of a plurality of types of elements. It is a feature.

  Therefore, for example, by adding an internal standard substance of a predetermined concentration to the waste liquid and comparing the intensity ratio of the internal standard substance and the radiation of each element in the detected radiation, the concentration of multiple metal oxides can be accurately determined. Can be calculated.

  In the apparatus for detecting a metal oxide in a waste liquid according to the present invention, the measurement apparatus calculates the concentration of an element contained in the waste liquid based on the detected radiation and the intensity ratio of the radiation of a plurality of types of elements, and is contained in the waste liquid. The concentration of the metal oxide is calculated based on the concentration of the element to be processed and the molecular weight of the metal oxide.

  Therefore, by calculating the concentration of each element from the intensity ratio of the radiation of each element and calculating the concentration of the metal oxide based on the concentration of each element and the molecular weight of the metal oxide, the concentration of the metal oxide is increased. It can be calculated with accuracy.

  In the apparatus for detecting a metal oxide in waste liquid according to the present invention, the radiation irradiator is an X-ray irradiator that irradiates X-rays, and the detector detects fluorescent X-rays generated from the waste liquid by X-ray irradiation. It is said.

  Therefore, when the X irradiator irradiates the waste liquid with X through the detection window of the sealed container, the detector detects the fluorescent X generated from the waste liquid by the X irradiation and outputs it to the measuring device. Based on the detection result, the concentration of the metal oxide contained in the waste liquid is measured. As a result, the total amount of metal oxide in the high level radioactive liquid waste can be detected with high accuracy.

  The method for detecting a metal oxide in a waste liquid according to the present invention includes a step of adding a standard substance of a predetermined concentration to the waste liquid, and a step of irradiating the precipitate in the waste liquid filled in the sealed container with radiation. And calculating the concentration of metal oxides contained in the waste liquid based on the standard substance and the intensity ratio of the radiation of multiple types of elements based on the detection results And a step of performing.

  Therefore, the concentration of the plurality of metal oxides can be calculated with high accuracy by comparing the intensity ratio between the internal standard substance in the detected radiation and the radiation in each element. As a result, the total amount of metal oxide in the high level radioactive liquid waste can be detected with high accuracy.

  In the method for detecting a metal oxide in a waste liquid according to the present invention, the concentration of an element contained in the waste liquid is calculated based on the detected radiation and the intensity ratio of the radiation of the standard substance and a plurality of types of elements, and contained in the waste liquid. It is characterized in that the concentration of the metal oxide is calculated based on the concentration of the element and the molecular weight of the metal oxide.

  Therefore, by calculating the concentration of each element from the intensity ratio of the radiation of each element and calculating the concentration of the metal oxide based on the concentration of each element and the molecular weight of the metal oxide, the concentration of the metal oxide is increased. It can be calculated with accuracy.

  In the method for detecting a metal oxide in the waste liquid according to the present invention, the step of filling the waste liquid into the sealed container from the opening formed in the upper part, and the step of closing the opening by attaching a polyethylene sheet to the opening And a step of arranging the sealed container upside down, and radiating radiation toward the detection window formed by the polyethylene sheet from below the sealed container.

  Therefore, by placing the sealed container filled with the waste liquid upside down, the solid matter containing the metal oxide in the sealed container is precipitated in the solution and collected on the lower detection window side, so that radiation irradiation is performed. By irradiating radiation toward the detection window from below, the solid can be properly irradiated to the solid matter containing the metal oxide.

  According to the apparatus and method for detecting metal oxides in the waste liquid of the present invention, since radiation analysis is used, the total amount of metal oxides in the high-level radioactive liquid waste can be detected with high accuracy.

FIG. 1 is a schematic view showing a metal oxide detection device in waste liquid of this embodiment. FIG. 2 is a schematic diagram illustrating a method for detecting a metal oxide in the waste liquid according to the present embodiment. FIG. 3 is a schematic diagram illustrating a method for detecting a metal oxide in the waste liquid according to the present embodiment. FIG. 4 is a flowchart showing a method for detecting a metal oxide in waste liquid. FIG. 5 is a graph showing fluorescent X-ray intensity with respect to X-ray energy. FIG. 6 is a table showing oxide forms for the detection elements. FIG. 7 is a schematic diagram showing a process for reprocessing spent nuclear fuel.

  Exemplary embodiments of a detection apparatus and method for metal oxide in waste liquid according to the present invention will be described below in detail with reference to the accompanying drawings. In addition, this invention is not limited by this embodiment, and when there are two or more embodiments, what comprises combining each embodiment is also included.

  FIG. 7 is a schematic diagram showing a process for reprocessing spent nuclear fuel.

  The apparatus and method for detecting a metal oxide in a waste liquid according to the present embodiment is used for a high-level radiation solution discharged in a shearing / dissolution process in a spent nuclear fuel reprocessing process.

  The process for reprocessing spent nuclear fuel will be described. As shown in FIG. 7, the spent nuclear fuel reprocessing process includes a spent nuclear fuel receiving / storage process, a shearing / dissolving process, a separation process, a refining process, a denitration process, and a product storage process. It is configured.

  In the acceptance / storage process, the cask 202 conveyed by the truck 201 is put into the fuel pool 203, and the spent nuclear fuel 204 is taken out in the cooling water and temporarily stored. In the shearing / dissolving step, the spent nuclear fuel 204 is taken out from the fuel pool 203, sheared by the shearing device 205, and then charged into the melting device 206 to be melted. Since waste gas is generated in this shearing process, the generated waste gas is sent to a waste gas processing apparatus for processing, although not shown. In the melting step, nitric acid 207 is stored in the melting device 206, and the spent nuclear fuel 204 is dissolved by the nitric acid 207, whereby uranium 208, plutonium 209, fission products (high level radioactive waste) 210 are stored. And so on. Further, in the dissolution process, the insoluble matter (foreign matter) 211 such as the cladding tube contained in the fuel solution is removed without being dissolved in the nitric acid 207 by a centrifugal separator or the like, and the high-level radioactive waste liquid containing the insoluble matter 211 is removed. Vitrify and store in a predetermined storage container.

  In the separation step, a uranium solution (uranium 208) or a plutonium solution (plutonium 209) is separated from the fuel solution as a solution. Specifically, in the separation step, fission products (high-level radioactive waste) 210 are first removed from the uranium solution and plutonium solution, cooled in a storage tank, and then solidified with a glass material and stored. In the separation step, the uranium solution and the plutonium solution are then separated.

  In the purification step, the uranium solution and the plutonium solution are purified into a uranium nitrate solution and a plutonium nitrate solution, respectively, and a part of the uranium nitrate solution is mixed with the plutonium nitrate solution to purify the uranium nitrate / plutonium solution. In this case, the Pu enrichment is adjusted for the purified uranium nitrate / plutonium solution. In the denitration step, the uranium nitrate solution and the uranium nitrate / plutonium solution are denitrated to purify the uranium oxide and the uranium / plutonium mixed oxide.

  In the product storage process, uranium oxide and uranium / plutonium mixed oxide are stored as products 212 and 213, respectively. Then, the fuel for loading can be manufactured by mixing the stored uranium oxide and the uranium / plutonium mixed oxide appropriately.

  The apparatus and method for detecting a metal oxide in a waste liquid according to the present embodiment is for a high-level radioactive waste liquid containing insoluble matter 211 generated in the shearing / dissolution process in the process of reprocessing the spent nuclear fuel described above. It is what you use. In the treatment of the high-level radioactive liquid waste, a predetermined amount of glass beads is added to the high-level radioactive liquid waste, and the glass solidified body is formed by melting and solidifying. At this time, the high-level radioactive waste liquid is a solution in which a metal oxide as a solvent is mixed in the solution, and the addition amount of the glass beads is determined with respect to the total amount of the metal oxide. That is, it is necessary to obtain the total amount of the metal oxide so that the mixing ratio of the metal oxide and the glass beads is optimized. The metal oxide detection apparatus and method determine the total amount of metal oxide in the high-level radioactive liquid waste.

  FIG. 1 is a schematic diagram illustrating a device for detecting a metal oxide in waste liquid according to the present embodiment, and FIGS. 2 and 3 are schematic diagrams illustrating a method for detecting a metal oxide in waste liquid according to the present embodiment.

  In this embodiment, as shown in FIG. 1, the metal oxide detection device 10 includes a first shielding box 11, a second shielding box 12, a manipulator 13, a sealed container 14, an X-ray irradiator (radiation detection). 15), a semiconductor detector (for example, silicon semiconductor detector / Si detector, Li detector) 16, and a measuring device 17.

  The first shielding box 11 and the second shielding box 12 have a box shape with a predetermined size and are configured by members capable of shielding radiation. In the large first shielding box 11, a small second shielding box 12 is disposed at the lower portion, and an opening 21 (see FIG. 3) is formed between the first shielding box 11 and the second shielding box 12. ing. In addition, you may close this opening part 21 with the transparent plate etc. which can permeate | transmit X-rays.

  The manipulator 13 is disposed in the first shielding box 11, the base end portion is supported by the wall portion, and can be operated by the external operation unit 22. The manipulator 13 is configured by providing a hand at the tip of an articulated arm.

  The sealed container 14 is a container filled with high-level radioactive waste liquid, and an opening 23 (see FIG. 2) is formed in the upper part. The sealed container 14 can be closed by attaching a polyethylene sheet 24 (see FIG. 2) to the opening 23 after the high-level radioactive waste liquid is filled. Then, by attaching a polyethylene sheet 24 to the opening 23, the polyethylene sheet 24 forms a detection window 25 through which X-rays can be transmitted. The operator can perform this operation in the first shielding box 11 by operating the manipulator 13.

  The X-ray irradiator 15 and the semiconductor detector 16 are disposed in the second shielding box 12. The X-ray irradiator 15 can irradiate the high-level radioactive liquid waste with X-rays (X-rays) through the detection window 25 of the sealed container 14. The semiconductor detector 16 can detect fluorescent X-rays generated from high-level radioactive liquid waste by X-ray irradiation. At this time, the sealed container 14 is disposed so that the detection window 25 is positioned at the lower part in the vertical direction and coincides with the opening 21, and the X-ray irradiator 15 is directed toward the detection window 25 from below the sealed container 14. Irradiate. Note that the X-ray irradiator 15 and the semiconductor detector 16 can be safely and easily maintained by arranging the X-ray irradiator 15 and the semiconductor detector 16 in the second shielding box 12 separate from the sealed container 14. it can.

  The measuring device 17 measures the concentration of the metal oxide contained in the high-level radioactive liquid waste based on the detection result of the semiconductor detector 16. The measuring device 17 calculates the concentration of the metal oxide contained in the high-level radioactive liquid waste based on the detected fluorescent X-rays and the intensity ratio of the fluorescent X-rays in a plurality of types of elements. Specifically, the measuring device 17 calculates the concentration of the element contained in the high-level radioactive liquid waste based on the detected fluorescent X-rays and the intensity ratio of the fluorescent X-rays in a plurality of types of elements including the internal standard substance, and this high level The concentration of the metal oxide is calculated based on the concentration of the element contained in the radioactive liquid waste and the molecular weight of the metal oxide.

  Here, the metal oxide detection method in the waste liquid of this embodiment using the metal oxide detection device 10 will be described. FIG. 4 is a flowchart showing a method for detecting a metal oxide in a waste liquid, FIG. 5 is a graph showing fluorescent X-ray intensity with respect to X-ray energy, and FIG. 6 is a table showing an oxide form with respect to a detection element.

  The metal oxide detection method in the waste liquid according to the present embodiment includes a step of adding an internal standard substance having a predetermined concentration to the high level radioactive waste liquid, and a precipitated metal in the high level radioactive waste liquid filled in the sealed container 14. A step of irradiating the oxide with X-rays, a step of detecting fluorescent X-rays generated from the high-level radioactive liquid waste by the irradiation of X-rays, and a fluorescent X in the internal standard substance and plural kinds of elements based on the detection results And calculating the concentration of the metal oxide contained in the high-level radioactive liquid waste based on the intensity ratio of the lines.

  In the method for detecting a metal oxide in the waste liquid according to the present embodiment, as shown in FIG. That is, a predetermined amount of high-level radioactive liquid waste is collected in the shearing / dissolution process of reprocessing spent nuclear fuel, and this high-level radioactive liquid waste is introduced into the sealed container 14 from the opening 23 as shown in FIG. Fill. In step S12, the weight (mass) of the high-level radioactive liquid waste is measured.

  In step S13, an internal standard substance having a predetermined concentration is added to the high-level radioactive liquid waste. Here, yttrium (Y) is applied as the internal standard substance. However, the internal standard is not limited to yttrium (Y), but can be detected relatively easily without adding to the high-level radioactive waste liquid and interfering with the X-ray fluorescence spectrum of the element to be analyzed. If it is. For example, selenium (Se), rubidium (Rb), tin (Sn), antimony (Sb), erbium (Er), or the like may be applied.

  In step S14, the sample is mixed. That is, the high-level radioactive liquid waste and yttrium (Y) are mixed and homogenized in the sealed container 14. In step S15, the polyethylene sheet 24 is attached to the opening 23 of the sealed container 14 to close the opening 23. In step S <b> 16, as shown in FIG. 3, the hermetic container 14 is inverted to be placed upside down, and the detection window 25 (polyethylene sheet 24) is made to coincide with the opening 21. Then, in the high-level radioactive waste liquid in the sealed container 14, the metal oxide B in the solution A settles and settles on the detection window 25 (polyethylene sheet 24).

  In step S <b> 17, as shown in FIG. 1, the X-ray irradiator 15 irradiates X-rays from below the sealed container 14 toward the detection window 25 formed by the polyethylene sheet 24. Then, X-rays are irradiated to the metal oxide B of the high-level radioactive waste liquid through the detection window 25, and fluorescent X-rays are output. In step S <b> 18, the semiconductor detector 16 detects the fluorescent X-ray spectrum output from the metal oxide B and outputs it to the measuring device 17.

  Then, in step S19, the measuring device 17 calculates the concentration of the element contained in the high-level radioactive liquid waste based on the detected fluorescent X-ray, yttrium (Y), and the intensity ratio of the fluorescent X-ray in each element, In step S20, the concentration of the metal oxide is calculated based on the concentration of the element contained in the high-level radioactive liquid waste and the molecular weight of the metal oxide.

  That is, the fluorescent X-ray intensity with respect to the X-ray energy is generally defined as in the graph shown in FIG. Here, since the X-ray energy in each element is determined, the fluorescent X-ray intensity for each element is known. In this case, since the ratio of the peak value in each element is constant, if the amount (concentration) of one element is known, the amount (concentration) of the other element can also be known. Here, since yttrium (Y) is added as an internal standard substance to the high-level radioactive liquid waste, it is contained in the high-level radioactive liquid waste based on the intensity ratio of fluorescent X-rays between yttrium (Y) and other elements. The amount (concentration) of the element can be calculated.

For example, the concentration of iron (Fe) contained in the high-level radioactive liquid waste is calculated by the following mathematical formula. Here, a standard material to which a predetermined amount of iron (Fe) and yttrium (Y) is added in advance is prepared, the standard material is irradiated with X-rays, and the output fluorescent X-ray intensity is measured. Then, the ratio of the fluorescent X-ray intensity (peak value) in iron (Fe) to the fluorescent X-ray intensity (peak value) in yttrium (Y) is obtained, and the sensitivity coefficient of Fe is calculated.
Fe sensitivity coefficient = (Fe concentration of standard material) /
(Fe fluorescent X-ray intensity of standard substance / Y fluorescent X-ray intensity of standard substance)

When the sensitivity coefficient of Fe is calculated using a standard substance, this time, X-rays are irradiated to a high-level radioactive liquid waste to which a predetermined amount of yttrium (Y) is added, and the output fluorescent X-ray intensity is measured. . Then, the Fe concentration (the measured value of Fe) is calculated using the output fluorescent X-ray intensity and the sensitivity coefficient of Fe.
Fe measurement value = (Fe fluorescence intensity / added Y fluorescence intensity) × (Fe sensitivity coefficient)

In addition, as shown in FIG. 6, in the high-level radioactive liquid waste, the form of the metal oxide with respect to the detected element is known, and therefore, based on the concentration of the element contained in the high-level radioactive liquid waste and the molecular weight of the metal oxide. The concentration of the metal oxide is calculated. Here, the concentration is converted so that the total sum of the detected metal oxides becomes 100%.
For example, the concentration of Fe ₂ O ₃ is calculated by the following mathematical formula.
Fe ₂ O ₃ measured value = (Fe measured value × Fe ₂ O ₃ molecular weight) / (Fe atomic weight × 2)
Fe ₂ O ₃ concentration = Fe ₂ O ₃ measured value / Σ (metal oxide measured value)

Here, the Fe concentration in the high-level radioactive liquid waste was obtained, and the Fe ₂ O ₃ concentration, which is a metal oxide, was obtained from this Fe concentration. By the same detection method, the concentration of all the metal oxides in the high-level radioactive liquid waste Ask for.

  As described above, in the apparatus for detecting a metal oxide in the waste liquid according to the present embodiment, the sealed container 14 having the detection window 25 that is filled with the high-level radioactive waste liquid and allows X-rays to pass through, and the detection of the sealed container 14. X-ray irradiator 15 for irradiating high-level radioactive liquid waste with X-rays through window 25, semiconductor detector 16 for detecting fluorescent X-rays generated from high-level radioactive liquid waste by X-ray irradiation, and detection results of semiconductor detector 16 And a measuring device 17 for measuring the concentration of the metal oxide contained in the high-level radioactive liquid waste.

  Therefore, when the X-ray irradiator 15 irradiates the high-level radioactive waste liquid with X-rays through the detection window 25 of the sealed container 14, the semiconductor detector 16 detects fluorescent X-rays generated from the high-level radioactive waste liquid by the X-ray irradiation, In order to output to the measuring device 17, the measuring device 17 measures the concentration of the metal oxide contained in the high-level radioactive liquid waste based on the detection result of the semiconductor detector 16. As a result, the total amount of metal oxide in the high level radioactive liquid waste can be detected with high accuracy.

  In the apparatus for detecting a metal oxide in waste liquid according to the present embodiment, the sealed container 14 is arranged so that the detection window 25 is positioned at the lower part in the vertical direction, and the X-ray irradiator 15 is disposed from below the sealed container 14. X-rays are irradiated toward 25. Therefore, since the metal oxide in the sealed container 14 is precipitated in the solution, it is collected on the detection window 25 side located at the lower part, and the X-ray irradiator 15 emits X-rays toward the detection window 25 from below. By irradiating, it is possible to appropriately irradiate the metal oxide with X-rays.

  In the apparatus for detecting a metal oxide in a waste liquid according to the present embodiment, an opening 23 for filling a high-level radioactive waste liquid is provided in the sealed container 14, and a polyethylene sheet 24 is attached to the opening 23 so as to be closed. A detection window 25 is formed by the sheet 24. Therefore, by providing the opening 23 in the sealed container 14, waste liquid can be easily filled in the sealed container 14, and by installing the polyethylene sheet 24 in the opening 23, the opening 23 can be easily installed. Can be closed to form the detection window 25, and the structure can be simplified.

  In the apparatus for detecting a metal oxide in a waste liquid according to the present embodiment, the measuring apparatus 17 uses a metal oxide contained in the high-level radioactive waste liquid based on the detected fluorescent X-rays and the intensity ratio of the fluorescent X-rays of a plurality of types of elements. Calculate the concentration of the object. Therefore, for example, by adding an internal standard substance of a predetermined concentration to a high-level radioactive liquid waste, and comparing the intensity ratio of the detected internal standard substance in fluorescent X-rays and fluorescent X-rays in each element, a plurality of metal oxidations The concentration of the object can be calculated with high accuracy.

  In the apparatus for detecting a metal oxide in the waste liquid according to the present embodiment, the measuring apparatus 17 calculates the concentration of the element contained in the waste liquid based on the detected fluorescent X-rays and the intensity ratio of the fluorescent X-rays of a plurality of types of elements. The concentration of the metal oxide is calculated based on the concentration of the element contained in the high-level radioactive liquid waste and the molecular weight of the metal oxide. Accordingly, the concentration of each element is calculated from the intensity ratio of fluorescent X-rays in each element, and the concentration of the metal oxide is calculated based on the concentration of each element and the molecular weight of the metal oxide. Can be calculated with high accuracy.

  Further, in the method for detecting a metal oxide in the waste liquid according to the present embodiment, a step of adding an internal standard substance having a predetermined concentration to the high-level radioactive waste liquid, and a high-level radioactive material filled in the sealed container 14 The step of irradiating the precipitate in the waste liquid with X-rays, the step of detecting fluorescent X-rays generated from the high-level radioactive waste liquid by the X-ray irradiation, and the internal standard substance and plural kinds of elements based on the detection results And calculating the concentration of the metal oxide contained in the waste liquid based on the intensity ratio of the fluorescent X-rays.

  Therefore, the concentration of the plurality of metal oxides can be calculated with high accuracy by comparing the intensity ratio of the detected internal standard substance in the fluorescent X-ray and the fluorescent X-ray in each element. As a result, the total amount of metal oxide in the high level radioactive liquid waste can be detected with high accuracy.

  In the method for detecting a metal oxide in the waste liquid according to the present embodiment, a step of filling a high-level radioactive waste liquid into the sealed container 14 from the opening 23 formed in the upper part, and a polyethylene sheet 24 is attached to the opening 23. A step of closing the opening 23 and a step of arranging the sealed container 14 upside down are provided, and X-rays are irradiated from below the sealed container 14 toward the detection window 25 formed by the polyethylene sheet 24. Therefore, by disposing the sealed container 14 filled with the high-level radioactive waste liquid upside down, the metal oxide in the sealed container 14 is precipitated in the solution and collected on the detection window 25 side located below. The X-ray irradiator 15 irradiates X-rays toward the detection window 25 from below, so that X-rays can be appropriately irradiated onto the metal oxide.

  In the above-described embodiment, the detection window 25 is formed by closing the opening 23 of the sealed container 14 with the polyethylene sheet 24. However, the present invention is not limited to this configuration. Instead of the polyethylene sheet 24, a highly airtight lid may be attached. Further, a detection window may be provided in advance on the lower surface of the sealed container.

  In the above-described embodiment, the metal oxide detection device and method in the waste liquid of the present invention is used for the high-level radioactive waste liquid generated in the shearing / dissolution process in the process of reprocessing the spent nuclear fuel. However, the present invention is not limited to this, and any waste liquid can be used.

  Further, in the above-described embodiment, the metal oxide detection device and method in the waste liquid of the present invention has been described using X-rays as radiation, but activation analysis using neutrons and gamma rays instead of X-rays is performed. You may apply.

DESCRIPTION OF SYMBOLS 10 Metal oxide detection apparatus 11 1st shielding box 12 2nd shielding box 13 Manipulator 14 Airtight container 15 X-ray irradiator 16 Semiconductor detector 17 Measuring apparatus 21 Opening part 22 Operation part 23 Opening part 24 Polyethylene sheet 25 Detection window A Solution B Solids containing metal oxide

Claims (9)

A sealed container having a detection window filled with waste liquid and capable of transmitting radiation;
A radiation irradiator for irradiating the waste liquid with radiation through the detection window of the sealed container;
A detector for detecting radiation generated from the waste liquid by irradiation with radiation;
A measuring device for measuring the concentration of the metal oxide contained in the waste liquid based on the detection result of the detector;
An apparatus for detecting a metal oxide in a waste liquid, comprising:   The sealed container is arranged so that the detection window is positioned in a lower part in a vertical direction, and the radiation irradiator irradiates radiation toward the detection window from below the sealed container. The apparatus for detecting a metal oxide in a waste liquid according to 1.   2. The airtight container is provided with an opening for filling a waste liquid, and the detection window is formed by the polyethylene sheet when the opening is closed by mounting a polyethylene sheet. Or the detection apparatus of the metal oxide in the waste liquid of Claim 2.   The said measuring apparatus calculates the density | concentration of the metal oxide contained in a waste liquid based on the detected radiation and the intensity ratio of the radiation in a multiple types of element, The any one of Claims 1-3 characterized by the above-mentioned. The apparatus for detecting a metal oxide in the waste liquid according to the item.   The measuring device calculates the concentration of the element contained in the waste liquid based on the detected radiation and the intensity ratio of the radiation of a plurality of types of elements, and the metal based on the concentration of the element contained in the waste liquid and the molecular weight of the metal oxide. The apparatus for detecting a metal oxide in a waste liquid according to claim 4, wherein the concentration of the oxide is calculated.   The radiation irradiator is an X-ray irradiator that irradiates X-rays, and the detector detects fluorescent X-rays generated from waste liquid by irradiation of X-rays. An apparatus for detecting a metal oxide in a waste liquid as described in 1. Adding a standard substance of a predetermined concentration to the waste liquid;
Irradiating the precipitate in the waste liquid filled in the sealed container with radiation;
A step of detecting radiation generated from the waste liquid by irradiation with radiation;
Calculating the concentration of the metal oxide contained in the waste liquid based on the standard substance and the intensity ratio of radiation in the plurality of types of elements based on the detection result;
A method for detecting a metal oxide in a waste liquid.   Calculate the concentration of the element contained in the waste liquid based on the detected radiation and the intensity ratio of the radiation in the standard substance and multiple types of elements, and metal oxidation based on the concentration of the element contained in the waste liquid and the molecular weight of the metal oxide The method for detecting a metal oxide in a waste liquid according to claim 7, wherein the concentration of the substance is calculated.   A step of filling a closed container with waste liquid from an opening formed in the upper part, a step of attaching a polyethylene sheet to the opening to close the opening, and a step of arranging the sealed container upside down. The method for detecting a metal oxide in a waste liquid according to claim 7 or 8, wherein X-rays are irradiated from a lower side of the sealed container toward a detection window formed by the polyethylene sheet.

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