JPH05340861A - Non-destructive measuring device and method of amount of uranium included in radioactive waste product - Google Patents

Abstract

PURPOSE:To measure not only incineration ash and flocculated precipitate containing uranium but also radioactive waste products such as a ragged cloth and a paper towel by measuring the radioactive waste products which are housed in a large container with a simple operation. CONSTITUTION:A container 10 housing a radioactive waste product which contains uranium is placed stationarily. Gamma rays with each inherent energy which are released from the radioactive waste product within the container are detected by a sodium iodide detector 14. A multiple wave-height analyzer 20 analyzes the wave height of gamma-ray energy according to the detection signal. The gamma-ray intensity of U-235 and U238 contained in a waste product is calculated according to the peak area of a specified region of a gamma-ray energy spectrum which is analyzed by an analyzer using a data processing means 22 and then the content of U-235 and U-238 is determined according to the calibration curve which is obtained from a standard where the gamma-ray intensity and uranium content are known.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus and method for nondestructively measuring the amount of uranium contained in radioactive waste contained in a container from the outside of the container. More specifically, the present invention relates to a nondestructive measuring device and method for measuring the amount of uranium contained in a container by measuring the characteristic γ-ray spectrum of uranium emitted from the outside of the container.

[0002]

2. Description of the Related Art Among radioactive wastes generated from nuclear facilities handling uranium such as nuclear fuel processing facilities, combustible wastes are incinerated and reduced in volume. The incinerated ash generated at that time is usually enclosed in a 200 L drum and stored as a retained waste. It is necessary to measure the uranium content in order to manage the nuclear fission and potential nuclear fuel material in the drum so as not to be diverted without permission and to prevent a criticality accident. When destructive analysis is performed in which all drums are opened and incinerated ash is sampled and analyzed for this measurement, it takes a lot of time and money to obtain the analysis results. For this reason, conventionally, a technique of nondestructively measuring the content of the fissile material in the radioactive waste stored in the container has been proposed (Japanese Patent Publication No. 3-67239). With this technology,
A can containing the incineration ash of radioactive waste is transported into the opening of the well formed from the neutron moderator, and the nondestructive measurement is performed therein. A large number of neutron detectors such as a BF ₃ detector are provided around the side wall surrounding the opening of the well, and a gamma ray detector such as a sodium iodide detector is provided near the bottom of the opening of the well. Is at least 1
It is provided individually.

[0003]

Therefore, although the non-destructive measurement is possible with the above conventional technique, the structure of the well that receives the can containing the incinerated ash and the structure of the device that conveys the can into the opening of the well are not improved. It's extremely complicated. As a result, the volume and weight of the can are inevitably limited, a large container such as a 200 L drum can cannot be used, and the operation of the device is troublesome. The purpose of the present invention is 2
An object of the present invention is to provide an apparatus and method for nondestructively measuring the amount of uranium contained in a radioactive waste stored in a large container such as a 00L drum can with a simple operation. Another object of the present invention is to provide an apparatus and a method for easily measuring the amount of uranium contained in radioactive waste in a non-destructive manner by moving the measuring apparatus to a storage location of radioactive waste stored in a uniform density. Especially. Still another object of the present invention is to provide an apparatus and method for nondestructively measuring the amount of uranium contained in radioactive waste stored in a non-uniform density.

[0004]

In order to achieve the above object, the structure of the present invention will be described with reference to FIGS. 1 and 2 corresponding to the embodiments. INDUSTRIAL APPLICABILITY The present invention has a uniform storage state density such as a coagulated precipitate generated from incineration ash or a waste liquid treatment process, or a storage state density such as a rag cloth or a paper towel. An apparatus and method for nondestructively measuring the amount of uranium contained in non-uniform radioactive waste. As shown in FIG. 1, a non-destructive measuring apparatus for uranium contained in radioactive waste according to a first aspect of the present invention, as shown in FIG. 1, is a container 10 for storing radioactive waste containing uranium.
And a means 12 for locating each of them; a sodium iodide detector 14 for detecting gamma rays of respective unique energies emitted from the radioactive waste in the container 10;
A multi-height analyzer 20 for performing a wave height analysis of gamma ray energy based on a detection signal of γ-ray; a uranium isotope content is obtained by destructive analysis of a calibrating radioactive waste of the same kind as the radioactive waste, and the calibrating radioactive U-2 contained in the radioactive waste for calibration using the sodium iodide detector 14 and the multiple wave height analyzer 20 after storing the waste in the container 10
35 and U-238 gamma ray intensities are obtained, a calibration curve prepared from the relationship between the gamma ray intensities and the uranium isotope content is stored, and the peak of a predetermined region of the gamma ray energy spectrum analyzed by the analyzer 20 is stored. Data processing means 22 for calculating the gamma ray intensities of U-235 and U-238 contained in the waste from the area and determining the contents of U-235 and U-238 from the gamma ray intensity and the calibration curve. A first moving means 16 capable of approaching the detector 14 to the position where the detector 14 faces the entire container 10 placed by the placing means 12, and an analyzer 20 following the moving means 16. The data processing means 2
And a second moving means 26 capable of moving 2.

As shown in FIG. 2, a nondestructive measuring device for the amount of uranium contained in radioactive waste, which is a second aspect of the present invention, is a container 30 containing radioactive waste containing uranium.
A turntable 32 on which the rotating table 32 is mounted;
A; sodium iodide detector 40 for detecting gamma rays of respective unique energies emitted from the radioactive waste in the container 30; a third detector 40 which is accessible to the container 30 mounted on the rotary table 32; Moving means 42; detector elevating means 44 capable of elevating and lowering to at least the height of the container 30;
A controller 39 for controlling the rotating means 34 and the detector elevating means 44; a wave height analysis of gamma ray energy based on a signal detected by the detector 40 while the container 30 is rotating and the detector 40 is ascending and descending. A multi-wave height analyzer 46 for performing a destructive analysis of the calibration radioactive waste of the same kind as the radioactive waste to obtain a uranium isotope content, and storing the calibration radioactive waste in a container 30 to U-235 and U- contained in the radioactive waste for calibration using the sodium iodide detector 40 and the multi-wave height analyzer 46.
The gamma ray intensity of 238 is obtained, a calibration curve prepared from the relationship between the gamma ray intensity and the uranium isotope content is stored, and the discard is made from the peak area of a predetermined region of the gamma ray energy spectrum analyzed by the analyzer 46. The gamma ray intensities of U-235 and U-238 contained in the object are calculated, and U-235 is calculated from this gamma ray intensity and the calibration curve.
And data processing means 50 for determining the contents of U-238
It is characterized by having and.

The nondestructive measuring apparatus for the amount of uranium contained in radioactive waste according to the third aspect of the present invention is the gamma ray source 36 for irradiating the container 30 mounted on the rotary table 32 with gamma rays in addition to the second aspect. And a gamma-ray source raising / lowering means 38 capable of raising / lowering the gamma-ray source 36 to at least the height of the container 30.
It is provided at a position opposite to and detects the gamma rays emitted from the gamma ray source 36 and transmitted through the container 30.

The nondestructive measurement method of the amount of uranium contained in the radioactive waste according to the fourth aspect of the present invention is based on the destructive analysis value of the uranium-containing radioactive waste to be measured as shown in FIG. Step 4a of preparing a calibration radioactive waste having a known uranium isotope content; Step 4b of storing this calibration radioactive waste in a container 10; At a predetermined position facing the entire container 10 in the vicinity of this container 10. Step 4c of detecting by the gamma ray detector 14 the gamma rays of respective unique energies emitted from the calibration radioactive waste in the container 10.
And; based on the detection signal of the detector 14, the multiple wave height analyzer 2
Step 4d of performing crest analysis of gamma ray energy by 0
Data processing means 2 from the peak area of a predetermined region of the gamma ray energy spectrum analyzed by the analyzer 20.
U-235 contained in the radioactive waste for calibration according to 2.
And step 4e of determining the gamma ray intensity of U-238; step 4f of creating a calibration curve from the gamma ray intensity and the uranium destructive analysis value; and storing radioactive waste whose uranium isotope content is to be measured in the container 10. Step 4g for carrying out; and the radioactive radioactive substance for measurement stored in the container 10 of the step 4g by the detector 14 by moving the sodium iodide detector 14 to a predetermined position near the container 10 of the step 4g and facing the entire container 10. A step 4h of detecting gamma rays of respective peculiar energies emitted from the waste; a step 4i of performing crest analysis of gamma ray energy by the analyzer 20 based on a detection signal of the sodium iodide detector 14; From the peak area of a predetermined region of the gamma ray energy spectrum analyzed in step 20, the measuring radioactivity is measured by the data processing means 22. U-235 and contained in the wastes U-
Step 4j for determining the gamma ray intensity of 238;
and a step 4k for determining the contents of U-235 and U-238 in the radioactive waste for measurement by comparing the gamma ray intensity of j with the calibration curve of step 4f.

The nondestructive measurement method for the amount of uranium contained in radioactive waste, which is the fifth aspect of the present invention, is based on the destructive analysis value of the uranium-containing radioactive waste to be measured, as shown in FIG. Step 5a for preparing a calibration radioactive waste having a known uranium isotope content; Step 5b for storing the calibration radioactive waste in a container 30;
Step 5c of placing on the No. 2; Step 5d of detecting by the gamma ray detector 40 the gamma rays of the specific energy emitted from the calibration radioactive waste in the container 30 at a predetermined position near the container 30 placed on the rotating table 32. And the detector 4
Step 5e of performing wave height analysis of gamma ray energy by the multiple wave height analyzer 46 based on the detection signal of 0; and from the peak area of a predetermined region of the gamma ray energy spectrum analyzed by the analyzer 46, the data processing means 50 performs the calibration. -235 and U-238 included in radioactive waste for use
5f for obtaining the gamma ray intensity of; and 5g for creating a calibration curve from the gamma ray intensity and the uranium breakdown analysis value
And; step 5h of storing uranium-containing measuring radioactive waste of the same type as the calibration radioactive waste in the container 30.
And a step 5i of placing the container 30 of the step 5h on the turntable 32 and performing the steps 5d to 5e.
Data processing means 5 from the peak area of a predetermined region of the gamma ray energy spectrum analyzed by the analyzer 46.
U-235 included in the radioactive waste for measurement according to 0
And a step 5j of obtaining the gamma ray intensity of U-238; and a step 5k of obtaining the contents of U-235 and U-238 of the radioactive waste for measurement from the gamma ray intensity of the step 5j and the calibration curve of the step 5g. It is characterized by including.

The nondestructive measurement method of the amount of uranium contained in the radioactive waste, which is the sixth aspect of the present invention, comprises a step 6a of placing an empty container 30 on the rotary table 32 as shown in FIG. Step 6b of irradiating the empty container 30 mounted on 32 with gamma rays from the gamma ray source 36; and gamma ray source 36 at a predetermined position near the empty container 30 mounted on the turntable 32.
Step 6c of detecting the gamma ray of the specific energy which is further irradiated and transmitted through the empty container 30 by the gamma ray detector 40; and the wave height of the gamma ray energy by the multiple wave height analyzer 46 based on the detection signal of the detector 40. Analysis step 6d; data processing means 50 based on the peak area of the gamma ray energy spectrum analyzed by the analyzer 46.
A step 6e for obtaining the gamma ray intensity for the empty container 30 by the following: a step 6f for preparing a calibration radioactive waste having a known uranium isotope content based on the destructive analysis value of the uranium-containing radioactive waste to be measured. A step 6g of storing the calibration radioactive waste in the empty container 30; and a step 6h of mounting the container 30 of the step 6g on the turntable 32.
The gamma ray detector 4 detects the gamma rays of specific energy emitted from the calibration radioactive waste in the container 30 at a predetermined position near the container 30 mounted on the turntable 32.
0 for detecting 6; step 6j for performing wave height analysis of gamma ray energy by the multiple wave height analyzer 46 based on the detection signal of the detector 40; and a predetermined region of the gamma ray energy spectrum analyzed by the analyzer 46. Step 6k for determining the gamma ray intensity of U-235 and U-238 contained in the calibration radioactive waste by the data processing means 50 from the peak area of the above; and a calibration curve from the gamma ray intensity of this step 6k and the uranium destruction analysis value. Process 6L to create
And; a container 3 in which the radioactive waste for measurement is stored on the turntable 32.
Step 6m for placing 0; container 3 placed on this turntable 32
Step 6n of irradiating 0 with gamma rays by the gamma ray source 36
And gamma rays of specific energy emitted from the gamma ray source 36 and transmitted through the container 30 at predetermined positions near the container 30 placed on the rotary table 32 and gamma rays of specific energy emitted from the container 30. Step 6o of detecting by the gamma ray detector 40; Step 6p of performing wave height analysis of gamma ray energy by the multiple wave height analyzer 46 based on the detection signal of the detector 40; and of the gamma ray energy spectrum analyzed by the analyzer 46. Step 6q for obtaining the transmitted gamma ray intensity of the radioactive waste for measurement and the gamma ray intensity of U-235 and U-238 from the peak area of a predetermined region by the data processing means 50; the gamma ray intensity of the step 6e and the step 6q. Calculate the self-absorption coefficient of the radioactive waste for measurement from the transmitted gamma-ray intensity of The U-235 and U-2 by
Step 6r for correcting the gamma ray intensity of 38; and this Step 6
From the corrected gamma-ray intensity of r and the calibration curve of step 6L, U-235 and U-238 of the radioactive waste for measurement were measured.
It is characterized by including a step 6s for determining the content of

[0010]

[Function] Non-destructive measurement of the amount of uranium in radioactive waste, such as incineration ash, which has a uniform density in the stored state, and radioactive waste, such as rag cloth and paper towel, which has a non-uniform density in the stored state In any case of non-destructive measurement of uranium content, first, a calibration radioactive waste with a known uranium content is prepared based on the uranium analysis value obtained by the destructive measurement of radioactive waste. A calibration curve is created by applying the nondestructive measurement method of the present invention to radioactive waste. As shown in FIG. 1, gamma ray detectors 14 made of sodium iodide are installed at predetermined positions in the vicinity of the drum can 10 so as to face the entire drum can 10.
Each unique energy gamma ray emitted from the measuring radioactive waste within 0 is detected. Gamma ray detector 14
The detection signal detected by is sent to the multiple wave height analyzer 20, where the wave height analysis of gamma ray energy is performed. The gamma ray intensity of U-235 and U-238 contained in the radioactive waste for measurement is obtained by the data processing means 22 from the peak area of the predetermined region of the gamma ray energy spectrum analyzed by the multiple wave height analyzer 20, and this gamma ray intensity U-235 and U-23 of radioactive waste for measurement by comparing with the calibration curve
Determine the content of 8. As shown in FIG.
When the radioactive waste has a uniform density such as incinerated ash and does not use a gamma ray source, on the contrary, when the radioactive waste has a low density like a rag and is non-uniform, Irradiates the drum 30 with gamma rays from a ¹³⁷ Cs gamma ray source 36 while rotating the turntable 32. The gamma ray of the specific energy transmitted through the drum can 30 is detected by the gamma ray detector 40 at a predetermined position near the drum can 30 placed on the rotary table 32.

Next, an apparatus according to a first embodiment of the present invention will be described with reference to the drawings. As shown in FIG. 1, reference numeral 12 is a base on which a 200-liter drum 10 containing incinerated ash is placed.
A sodium iodide detector 14 is arranged in front of the drum 10 to detect gamma rays of specific energy emitted from the radioactive waste in the drum 10.
The detector 14 is a first carriage 16 which is a first moving means.
Drum can 10 mounted on the base 12 and fixed on the base 12.
The whole can be approached to the position where the detector 14 faces. The output of the detector 14 is connected to a multiple wave height analyzer 20 via an amplifier 18, and the output of the multiple wave height analyzer 20 is connected to a computer 22 of the data processing means. In this computer 22, a calibration curve obtained from a standard whose gamma ray intensity and uranium content are known is stored in a memory. A printer 24 is connected to the computer 22.
The amplifier 18, the multi-wave height analyzer 20, the computer 22, and the printer 24 are stored in a storage device (not shown) such as a console or a rack, and then mounted on a second carriage 26 which is a second moving means. , Follows the first carriage 16 and moves to an appropriate place.

The amount of uranium contained in the radioactive waste was measured non-destructively as follows using the apparatus of the first embodiment thus constructed. First, based on the uranium analysis values obtained by destructive measurement of radioactive waste, incineration ash that is five types of calibration radioactive waste with a known uranium content is prepared, and these five types of incineration ash are separated. It was stored in a drum 10. A predetermined position facing the entire drum can 10 near the drum can 10, that is, as shown in FIG. 3, a gamma ray detector 14 is installed at a position 80 cm away from the center line of the drum can 10. Gamma rays of specific energy emitted from the incineration ash of the radioactive waste for calibration were detected. The detection signal detected by the gamma ray detector 14 is amplified by the amplifier 18 and the multi-wave height analyzer 20
And the wave height analysis of the gamma ray energy was performed here.
As shown in FIG. 4, the computer 22 displays the peak area (hatched portion) of the gamma ray energy spectrum (185 KeV) region S1 of U-235 analyzed by the multiple wave height analyzer 20 and the Pa-234 m corresponding to U-238. The gamma ray intensity of U-235 and U-238 contained in the incineration ash of the radioactive waste for calibration is obtained from the peak area (hatched portion) of the gamma ray energy spectrum (1001 KeV) region S2, and the gamma ray intensity and the uranium analysis value From the relationship, a calibration curve indicated by A in FIG. 5 and a calibration curve indicated by C in FIG. 6 were created. The relationship between the gamma ray intensity of these calibration curves and the uranium analysis value is stored in the memory of the computer 22.
In the decay of U-238, there is a gamma ray of about 50 keV that is directly emitted, but this gamma ray is unsuitable for measurement because it has low energy and is significantly absorbed and attenuated by a substance. Therefore, in order to obtain the gamma ray intensity of U-238, the gamma ray intensity of 1001 keV emitted by Pa-234m that is in permanent radiation equilibrium with the following U-238 was adopted as the measurement target. However, in the above radiation balance formula, the half-life is shown in parentheses.

Next, the incineration ash for measurement of the same kind as the incineration ash for calibration was stored in the drum can 10. For the subsequent measurement operation, the same measurement operation as in the case of the above-mentioned calibration incineration ash is repeated, and the U-23 contained in the measurement incineration ash by the computer 22 is repeated.
5 and U-238 gamma ray intensities were obtained, the contents of U-235 and U-238 in the measurement incineration ash were obtained from the gamma ray intensities and the calibration curve stored in the memory, and printed on the printer 24. ..

Next, an apparatus according to a second embodiment of the present invention will be described with reference to the drawings. First, as shown in FIG. 2, reference numeral 32 is a rotary table on which a 200-liter drum 30 for storing incineration ash as radioactive waste containing uranium is placed. The turntable 32 is configured to be rotatable by a rotation means 34 such as a motor. In front of the drum 30 is a sodium iodide detector 4 for detecting gamma rays of specific energy emitted from radioactive waste in the drum 30.
0 is placed. The sodium iodide detector 40 moves horizontally and vertically by a detector moving means 42 including a motor and a detector elevating means 44 including a motor. The detector 40 is configured to be accessible to the container 30 placed on the rotary table 32 by the moving means 42, and can be raised and lowered to at least the height of the drum can 30 by the detector raising and lowering means 44. Three
Reference numeral 9 denotes a controller, which controls the rotating means 34 and the detector elevating means 44, respectively. A multiple wave height analyzer 46, which performs wave height analysis of gamma ray energy based on a signal detected from the detector 40 while the drum 30 is rotating or when the detector 40 is moving up and down, is connected to the output of the detector 40 via an amplifier 48. It The output of the multiple wave height analyzer 46 is connected to the computer 50 of the data processing means. In the computer 50, a calibration curve obtained from a standard whose gamma ray intensity and uranium content are known is stored in a memory. A printer 52 is connected to the computer 50.

The amount of uranium contained in the radioactive waste was measured non-destructively as follows using the apparatus of the second embodiment thus constructed. First, based on the uranium analysis values obtained by destructive measurement of radioactive waste, incinerator ash, which is five kinds of calibration radioactive waste with known uranium content, was prepared, and these calibration radioactive wastes were separately separated. Drum can 3
Stored at 0. The drum can 30 is placed on the rotary table 32, and the detector 40 is used while rotating the rotary table 32 at a rotation speed of 10 rpm. The gamma rays of the specific energy emitted from the incineration ash of the radioactive radioactive waste in the drum can 30 are detected. Was detected. Thereafter, the same operation as in the case of the first embodiment was performed to prepare the calibration curve shown by B in FIG. 5 and the calibration curve shown by D in FIG. Next, the incineration ash of the radioactive waste for measurement is stored in the drum 30. For the subsequent measurement operation, the same measurement operation as in the case of the radioactive waste for calibration is repeated, and the gamma ray intensity of U-235 and U-238 contained in the radioactive waste for measurement is calculated by the computer 50.
From this gamma ray intensity and the calibration curve stored in the memory, U-235 and U-2 of the radioactive waste for measurement are measured.
The content of 38 was determined and printed on the printer 52.

[0016]

As described above, the present invention has the following excellent effects. Unlike the conventional example, a large number of neutron detectors are not required, and one sodium iodide detector may be provided, so that the structure of the device is simple, and therefore the volume and weight of the container for storing radioactive waste. Not restricted by. Measurement is possible only by placing the container for storing radioactive waste or rotating it, and the measuring means including the detector, analyzer, data processing means, gamma ray source, etc. are all small and easy to move. Therefore, radioactive waste stored in a large container such as a 200 L drum can can be measured with a simple operation. By using the gamma ray source together, a wide range of types of radioactive waste can be accurately measured without being restricted by the packing density of the low-density radioactive waste stored in the container.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a nondestructive measurement device that is an embodiment of the present invention.

FIG. 2 is a configuration diagram of a nondestructive measurement device that is another embodiment of the present invention.

FIG. 3 is a diagram showing a positional relationship between a drum that stores the radioactive waste and a gamma ray detector.

FIG. 4 is a diagram showing a gamma ray energy spectrum detected by the sodium iodide detector.

FIG. 5 is a view showing a calibration curve of U-235.

FIG. 6 is a diagram showing a calibration curve of U-238.

[Explanation of symbols]

 10, 30 container 12 container stationary means 14, 40 sodium iodide detector 16 first moving means 20, 46 multiple wave height analyzer 22, 50 data processing means 26 second moving means 32 rotary table 34 rotating means 36 gamma ray source 38 gamma ray elevating means 42 third moving means 44 detector elevating means

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[Procedure amendment]

[Submission date] October 6, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0014

[Correction method] Change

[Correction content]

Next, an apparatus according to a second embodiment of the present invention will be described with reference to the drawings. First, as shown in FIG. 2, reference numeral 32 denotes a turntable on which a 200-liter drum 30 for storing incineration ash containing uranium as radioactive waste is placed. The rotating table 32 is a rotating means 34 such as a motor.
It is configured to be rotatable. A sodium iodide detector 40 is arranged in front of the drum 30 to detect gamma rays of specific energy emitted from radioactive waste in the drum 30. The sodium iodide detector 40 is horizontally and vertically moved by a detector moving means 42 and a detector elevating means 44 including a motor. Detector 40
Is configured to be accessible to the container 30 placed on the rotary table 32 by the moving means 42, and can be raised and lowered to at least the height of the drum can 30 by the detector raising and lowering means 44.
Reference numeral 39 denotes a controller, which controls the rotating means 34 and the detector elevating means 44, respectively. A multiple wave height analyzer 46, which performs wave height analysis of gamma ray energy based on a signal detected by the detector 40 while the drum 30 is rotating and when the detector 40 is moving up and down, is connected to the output of the detector 40 via an amplifier 48. It The output of the multiple wave height analyzer 46 is connected to the computer 50 of the data processing means. In the computer 50, a calibration curve obtained from a standard whose gamma ray intensity and uranium content are known is stored in a memory. A printer 52 is connected to the computer 50.

Claims (6)

[Claims] 1. A means (12) for placing a container (10) accommodating radioactive waste containing uranium, and detecting the gamma ray of each unique energy emitted from the radioactive waste in the container (10). Sodium iodide detector (14), a multiple wave height analyzer (20) for performing wave height analysis of gamma ray energy based on the detection signal of the detector (14), and a radioactive waste for calibration of the same kind as the radioactive waste. Destructive analysis of the substance to determine the uranium isotope content, and the radioactive radioactive waste for calibration is stored in the container (10), the sodium iodide detector (14) and the multiple wave height analyzer (20) U-235 and U-23 contained in the radioactive waste for calibration using
The gamma ray intensity of 8 was obtained, and the calibration curve prepared from the relationship between the gamma ray intensity and the uranium isotope content was stored,
The gamma ray intensity of U-235 and U-238 contained in the waste is arithmetically processed from the peak area of a predetermined region of the gamma ray energy spectrum analyzed by the analyzer (20), and the gamma ray intensity and the calibration curve are calculated. Processing means (22) for determining the contents of U-235 and U-238 from
A first moving means (16) capable of approaching the detector (14) to a position where the detector (14) faces the entire container (10) placed by the placing means (12); Non-destructive measurement of the amount of uranium contained in radioactive waste provided with a second moving means (26) capable of moving the analyzer (20) and the data processing means (22) following the means (16) apparatus. 2. A rotating table (32) on which a container (30) containing radioactive waste containing uranium is placed, a rotating means (34) of the rotating table (32), and a radioactive material inside the container (30). A sodium iodide detector (40) that detects gamma rays of each unique energy emitted from waste, and a detector (40) that is accessible to a container (30) mounted on the rotary table (32). 3 moving means (42), a detector raising / lowering means (44) capable of raising / lowering to at least the height of the container (30), a controller for controlling the rotating means (34) and the detector raising / lowering means (44) (39) and a multiple wave height analyzer for performing wave height analysis of gamma ray energy based on a signal detected from the detector (40) during rotation of the container (30) and ascending / descending of the detector (40) ( 46), destructive analysis of the calibration radioactive waste of the same type as the radioactive waste to obtain the uranium isotope content, and the calibration radiation. Waste the container (30) wherein a sodium iodide detector is housed in (40) and the multichannel pulse height analyzer U-235 contained in the calibration radioactive waste using (46) and U-23
The gamma ray intensity of 8 was obtained, and the calibration curve prepared from the relationship between the gamma ray intensity and the uranium isotope content was stored,
The gamma ray intensity of U-235 and U-238 contained in the waste is calculated from the peak area of a predetermined region of the gamma ray energy spectrum analyzed by the analyzer (46), and the gamma ray intensity and the calibration curve are calculated. To U-235 and U-238, the data processing means (50) for determining the contents of the uranium contained in the radioactive waste. 3. A turntable (32) on which a container (30) containing radioactive waste containing uranium is placed, a rotating means (34) of the turntable (32), and a turntable (32). Gamma ray source (36) for irradiating the container (30) with gamma rays, gamma ray source elevating means (38) capable of elevating and lowering the gamma ray source (36) to at least the height of the container (30), and the gamma ray source (36 ), A sodium iodide detector (40) for detecting gamma rays emitted from the gamma ray source (36) and transmitted through the container (30), and the detector (40) on the rotary table. A third moving means (42) accessible to the container (30) mounted on the (32) and a detector capable of moving up and down at least to the height of the container (30) in synchronization with the gamma ray source lifting means (38). An elevating means (44), a controller (39) for controlling the rotating means (34), the gamma ray source elevating means (38) and the detector elevating means (44), Multiple wave height analyzer (46) for performing wave height analysis of gamma ray energy based on a signal detected from the detector (40) while rotating the container (30) and moving up and down the detector (40), The uranium isotope content is obtained by destructive analysis of the calibration radioactive waste of the same type as the radioactive waste, and the calibration radioactive waste is stored in the container (30) and the sodium iodide detector (40 ) And U-235 and U-23 contained in the calibration radioactive waste by using the multiple wave height analyzer (46).
The gamma ray intensity of 8 was obtained, and the calibration curve prepared from the relationship between the gamma ray intensity and the uranium isotope content was stored,
The gamma ray intensity of U-235 and U-238 contained in the waste is calculated from the peak area of a predetermined region of the gamma ray energy spectrum analyzed by the analyzer (46), and the gamma ray intensity and the calibration curve are calculated. To U-235 and U-238, the data processing means (50) for determining the contents of the uranium contained in the radioactive waste. 4. (4a) A calibration radioactive waste having a known uranium isotope content is prepared based on the destructive analysis value of the uranium-containing radioactive waste to be measured, and (4b) the calibration radioactive waste. In a container (10), (4c) the radioactive waste for calibration in the container (10) by a gamma ray detector (14) at a predetermined position facing the entire container (10) in the vicinity of the container (10). Γ-rays of each unique energy emitted from, is detected, (4d) the wave height analysis of the gamma-ray energy by the multiple wave height analyzer (20) based on the detection signal of the detector (14), (4e) the analysis U- contained in the radioactive waste for calibration by the data processing means (22) from the peak area of a predetermined region of the gamma ray energy spectrum analyzed by the instrument (20).
The gamma ray intensities of 235 and U-238 are obtained, (4f) a calibration curve is prepared from the gamma ray intensities and the uranium destructive analysis values, and (4g) the radioactive waste whose uranium isotope content is to be measured is stored in a container (10 ), (4h) the container of (4g)
(10) For measurement in which the sodium iodide detector (14) is moved to a predetermined position facing the entire container (10) in the vicinity and stored in the container (10) of (4g) by this detector (14) Detects each unique energy gamma ray emitted from radioactive waste,
(4i) the crest analysis of gamma ray energy by the analyzer (20) based on the detection signal of the sodium iodide detector (14), (4j) the gamma ray energy spectrum analyzed by the analyzer (20). The gamma ray intensity of U-235 and U-238 contained in the radioactive waste for measurement is obtained from the peak area of a predetermined region by the data processing means (22), and (4k) the gamma ray intensity of (4j) and the ( A method for nondestructive measurement of the amount of uranium contained in radioactive waste by comparing the calibration curve of 4f) with the U-235 and U-238 contents of the radioactive waste for measurement. 5. (5a) A calibration radioactive waste having a known uranium isotope content is prepared based on the destructive analysis value of the uranium-containing radioactive waste to be measured, and (5b) the calibration radioactive waste. Stored in a container (30), (5c) the container (30) is placed on a turntable (32), (5d) the container placed on the turntable (32)
(30) The gamma ray of each unique energy emitted from the calibration radioactive waste in the container (30) at a predetermined position in the vicinity is detected by a gamma ray detector (40), and (5e) the detector (40 ), The wave height analysis of the gamma ray energy is performed by the multiple wave height analyzer (46) based on the detection signal of (5f) the analyzer.
U-235 and U-238 contained in the calibration radioactive waste by the data processing means (50) from the peak area of the predetermined region of the gamma ray energy spectrum analyzed in (46).
(5g) A calibration curve is prepared from the gamma ray intensity and the uranium breakdown analysis value, and (5h) a radioactive waste for measurement that contains uranium and is of the same type as the radioactive waste for calibration is stored in a container ( (5i) The container (3)
0) is placed on the rotary table (32), and the (5d) to the (5e)
(5j) U-235 contained in the radioactive waste for measurement by the data processing means (50) from the peak area of a predetermined region of the gamma ray energy spectrum analyzed by the analyzer (46), and The gamma ray intensity of U-238 was determined, and (5k) U-235 and U-2 of the radioactive waste for measurement were determined from the gamma ray intensity of (5j) and the calibration curve of (5g).
A method for nondestructively measuring the amount of uranium contained in radioactive waste for determining the content of 38. 6. (6a) An empty container (30) is placed on the turntable (32), and (6b) Gamma rays are applied to the empty container (30) placed on the turntable (32) by a gamma ray source (36). Irradiate (6c) the rotating table
The gamma ray detector (40) detects gamma rays of specific energy which are emitted from the gamma ray source (36) at a predetermined position near the empty vessel (30) mounted on (32) and which are transmitted through the empty vessel (30). (6d) the wave height analysis of the gamma ray energy by the multiple wave height analyzer (46) based on the detection signal of the detector (40), (6e) the gamma rays analyzed by the analyzer (46). Data processing means from peak area of energy spectrum (50)
Determine the gamma ray intensity for the empty container (30) by
(6f) Prepare a calibration radioactive waste with known uranium isotope content based on the destructive analysis value of the uranium-containing radioactive waste to be measured, (6g) the calibration radioactive waste in a container (30) (6h) The container (30) from (6g) was rotated (3
(6i) The container (3) placed on the rotating table (32) in (6h) above.
0) γ-rays of specific energy emitted from the calibration radioactive waste in the container (30) at a predetermined position in the vicinity are detected by a gamma-ray detector (40), (6j) the detector
Based on the detection signal of (40), the wave height analysis of gamma ray energy is performed by the multiple wave height analyzer (46), and (6k) the analyzer (4
From the peak area of a predetermined region of the gamma ray energy spectrum analyzed in 6), the gamma ray intensity of U-235 and U-238 contained in the calibration radioactive waste is obtained by the data processing means (50), and (6L) (6k) to create a calibration curve from the gamma ray intensity and the uranium destruction analysis value, (6m) the container (30) containing the radioactive waste for measurement on the rotary table (32), (6n) the rotary table (32) above (6m) container (3
(0) gamma ray is irradiated from the gamma ray source (36), and (6o) the container (30) is irradiated from the gamma ray source (36) at a predetermined position near the container (30) mounted on the rotary table (32). Gamma rays of specific energy transmitted through and gamma rays of specific energy emitted from the container (30) are detected by a gamma ray detector (40), and (6p) the detection signal of the detector (40) is detected. Based on the wave height analysis of the gamma ray energy by the multiple wave height analyzer (46), (6q) by the data processing means (50) from the peak area of a predetermined region of the gamma ray energy spectrum analyzed by the analyzer (46). Transmitted gamma ray intensity and U-235 and U-23 of the radioactive waste for measurement
(6r) The gamma ray intensity of (6r) is calculated from the gamma ray intensity of (6e) and the transmitted gamma ray intensity of (6q), and the self-absorption coefficient of the radioactive waste for measurement is calculated. And (6s) the corrected gamma ray intensity of (6r) and (6s)
A nondestructive measurement method of the amount of uranium contained in the radioactive waste, wherein the contents of U-235 and U-238 in the radioactive waste for measurement are determined from the calibration curve of L).