JP6674836B2 - Waste measuring device and waste measuring method - Google Patents

Description

  The present invention relates to a radioactive waste measuring device and a radioactive waste measuring method for measuring the radioactive concentration of radioactive waste.

  In the decommissioning of nuclear power facilities, radioactive waste such as radioactive waste and waste contaminated by radioactivity is generated as the facilities are dismantled. Since the treatment and disposal of these wastes is required according to the radioactivity concentration level, it is necessary to measure the radioactivity concentration. In the measurement of the radioactivity concentration, gamma rays emitted from a gamma ray source such as Co-60 or Cs-137 are mainly used.

  Radioactive waste includes metals such as pipes and valves, and concrete generated when buildings are dismantled. Conventionally, these wastes are stored in drums, and the drums are filled with mortar, sand, or the like, and then managed, treated, or disposed. In the management, processing and disposal, it is necessary to measure and quantify the radioactivity concentration of the waste stored in drums.

  As a method of measuring the radioactivity concentration in a drum can, for example, there is a method disclosed in Patent Document 1. In Patent Document 1, the energy spectrum of gamma rays emitted from radioactive waste in a drum can is measured while rotating the drum using the rotational symmetry of the drum, and the radionuclide such as Co-60 and Cs-137 is measured. Radioactivity concentration is quantified.

  In quantification, the effect of gamma ray attenuation by the waste itself in the drum can is evaluated and considered based on the ratio of the scattered radiation intensity to the non-scattered radiation intensity obtained from the measured energy spectrum.

  According to the method of Patent Document 1, even when there is a radioactivity concentration distribution or uneven distribution in the drum, it is possible to measure as an averaged value by measuring while rotating the drum.

JP 2000-56025 A

  By the way, when a drum can is used as a waste container, when the drum can is transported or buried in a disposal site, the drum can has a columnar shape. However, there is a problem that the size will increase.

  For this reason, it is being discussed to use a rectangular container as a storage container instead of a drum can.

  Further, regardless of whether the container is a drum or a rectangular container, when radioactive waste is stored in a container, a radioactivity concentration distribution or uneven distribution may occur in the container. It is difficult to imagine that if the radioactivity is evaluated assuming that the concentration in the container is uniform without considering the radioactivity concentration distribution and the possibility of uneven distribution, the evaluation error may be very large. Absent.

  In the case of a drum, as described above, according to the method described in Patent Literature 1, even if there is a radioactivity concentration distribution or uneven distribution in the drum, by measuring while rotating the drum, an averaged value is obtained. It is possible to measure.

  On the other hand, in the case of a rectangular container, the distance between the detector and the rectangular container cannot be kept constant when the container is rotated because it does not have rotational symmetry unlike a drum can. It is difficult to apply the method.

  Therefore, when the radioactive waste in the rectangular container has a concentration distribution, there is a problem that it is difficult to evaluate the influence of the high concentration portion on the low concentration portion.

  An object of the present invention is to provide a waste measurement device and a waste measurement method capable of evaluating radioactivity concentration with high accuracy and in a short time even when radioactive waste in a container has a radioactivity concentration distribution or uneven distribution. It is to realize.

  In order to achieve the above object, the present invention is configured as follows.

(1) In a waste measuring device, a dose rate distribution measuring device for measuring a dose rate of radioactive waste, and air dose rate distribution information of the radioactive waste are created from the dose rate measured by the dose rate distribution measuring device. A dose rate distribution analysis display device, a dose rate activity concentration conversion factor database storage device for storing a conversion factor from the air dose rate distribution information created by the dose rate distribution analysis display device to a radioactivity concentration, and the dose rate radiation Concentration distribution constraint that converts the air dose rate distribution information into radioactivity or radioactivity concentration distribution using the above conversion factor stored in the active density conversion coefficient database storage device, and generates radioactivity or radioactivity concentration distribution constraint conditions. A condition generator and gamma ray spectrum measurement for measuring a gamma ray spectrum emitted from a radionuclide of the radioactive waste contained in the radioactive waste container And the radioactivity in the container for evaluating the radioactive concentration of the radioactive waste contained in the radioactive waste container from the gamma ray spectrum measured by the gamma ray spectrum measuring device and the radioactivity or radioactivity concentration distribution constraint conditions. And a concentration evaluation device, wherein the radioactivity concentration distribution constraint condition is a condition that gives a relative magnitude relationship of radioactivity concentration between regions where the radioactive waste is virtually divided.
(2) In the waste measuring device, a dose rate distribution measuring device for measuring the dose rate of the radioactive waste, and air dose rate distribution information of the radioactive waste are created from the dose rate measured by the dose rate distribution measuring device. A dose rate distribution analysis display device; a dose rate activity concentration conversion factor database storage device for storing a conversion factor from the air dose rate distribution information created by the dose rate distribution analysis display device to an activity concentration; Concentration distribution constraint that converts the air dose rate distribution information into radioactivity or radioactivity concentration distribution using the above conversion factor stored in the active density conversion coefficient database storage device, and generates radioactivity or radioactivity concentration distribution constraint conditions. A condition generator and gamma ray spectrum measurement for measuring a gamma ray spectrum emitted from a radionuclide of the radioactive waste contained in the radioactive waste container And the radioactivity in the container for evaluating the radioactive concentration of the radioactive waste contained in the radioactive waste container from the gamma ray spectrum measured by the gamma ray spectrum measuring device and the radioactivity or radioactivity concentration distribution constraint conditions. A concentration evaluation device, and a waste information storage device that stores information on the radioactive waste at the time of planning the decommissioning of a nuclear power plant, and the concentration distribution constraint condition generation device includes a waste information storage device. The stored information on the radioactive waste is extracted to generate the radioactivity concentration distribution constraint condition.

( 3 ) In the waste measurement method, the dose rate of the radioactive waste is measured, and the air dose rate distribution information of the radioactive waste is created from the measured dose rate of the radioactive waste. The conversion factor from the information to the radioactivity concentration is stored in the dose rate radioactivity concentration conversion factor database storage device, and the air dose rate distribution is calculated using the conversion factor stored in the dose rate radioactivity concentration conversion factor database storage device. Converts information into radioactivity or radioactivity concentration distribution, generates radioactivity or radioactivity concentration distribution constraint conditions, stores the radioactive waste in a radioactive waste container, and stores the radioactive waste in the radioactive waste container. Measure the gamma-ray spectrum emitted from the radionuclide of the waste, and determine the gamma-ray spectrum and the radioactivity or radioactivity concentration distribution constraint described above. A waste measurement method for assessing the activity concentration morphism waste the radioactive waste contained in the container, the radioactivity level distribution constraint conditions between the dividing the radioactive waste virtually region It is a condition that gives a relative magnitude relationship between radioactivity concentrations .

  Even if the radioactive waste in the container has a radioactive concentration distribution or uneven distribution, a waste measuring device and a waste measuring method capable of evaluating the radioactive concentration with high accuracy and in a short time can be realized. .

1 is an overall configuration diagram of a waste measurement device according to a first embodiment of the present invention. FIG. 3 is a diagram illustrating a measurement flow using the waste measurement device according to the first embodiment of the present invention. It is a figure showing an example of a measurement result by PSF. It is a figure which shows an example of the display screen which displayed the analysis result of the air dose rate distribution information on the screen of the dose rate distribution analysis and display device. It is a figure which shows an example of the display screen which displayed the converted radioactivity concentration distribution information on the display part of the concentration distribution constraint condition generation apparatus. FIG. 4 is a diagram illustrating an example of generation of a constraint condition. FIG. 6 is an overall configuration diagram of a waste measurement device according to a second embodiment of the present invention. FIG. 7 is a diagram illustrating a measurement flow using a waste measurement device according to a second embodiment of the present invention.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

(Example 1)
FIG. 1 is an overall configuration diagram of a waste measurement device according to a first embodiment of the present invention. In the waste measuring apparatus according to the first embodiment of the present invention, the screening measurement (first stage) performed before storing the radioactive waste 1 in the radioactive waste container 5 and the radioactive waste 1 to the radioactive waste container 5 are performed. Storage (second stage), gamma ray spectrum measurement performed after storing radioactive waste 1 in radioactive waste container 5 (measuring gamma ray spectrum emitted from radionuclide of radioactive waste 1) and radioactivity concentration Radioactivity measurement and evaluation are performed through three stages of evaluation (third stage).

  The apparatus applied to the first-stage screening measurement includes an air dose rate distribution measuring apparatus 3 for measuring the air dose rate distribution 20 (shown in FIG. 3) of the radioactive waste 1, and measurement data of the air dose rate distribution measuring apparatus 3. Data collection device 2 that collects radioactive waste 1, a related position information storage device 9 that stores information on the positional relationship between the radioactive waste 1 and the air dose rate distribution measuring device 3, and the air dose rate distribution of the radioactive waste 1 from the measured data. A dose rate distribution analysis / display device 10 for analyzing and displaying the information 30 (shown in FIG. 4), a concentration distribution constraint condition generating device 11 for generating a concentration distribution constraint condition from a dose rate distribution analysis result, and a concentration distribution constraint condition generation A storage device 12 for storing a dose rate / radioactivity concentration conversion coefficient database (DB) for providing data to the device 11.

  In the second stage, the radioactive waste 1 is stored in the radioactive waste container 5.

  The apparatus for performing the third step includes a gamma ray spectrum measuring apparatus 4 for measuring the gamma ray energy spectrum of the radioactive waste 1 stored in the radioactive waste container 5, and a measurement result and a concentration distribution constraint condition generating apparatus 11 An in-vessel radioactivity concentration evaluation device 13 for evaluating the in-vessel radioactivity concentration from the determined concentration distribution constraint condition 21 (shown in FIG. 6), and an evaluation result display device 14 for displaying the evaluation result.

  FIG. 2 is a measurement flow using the waste measurement device according to the first embodiment of the present invention.

  As described above, the measurement is performed before the radioactive waste 1 is stored in the radioactive waste container 5 (step S1000), and the radioactive waste 1 is stored in the radioactive waste container 5 (step S3001). It comprises three steps of gamma ray spectrum measurement and radioactivity concentration evaluation (step S2000) performed after storing the radioactive waste 1 in the radioactive waste container 5.

  In the measurement by the waste measuring device of the present invention, first, the air dose rate distribution 20 of the radioactive waste 1 before being stored in the radioactive waste container 5 is measured using the air dose rate distribution measuring device 3 (step S1001). ).

  As an example of the air dose rate distribution measuring device 3 for measuring the air dose rate distribution 20, there is a plastic scintillation fiber (PSF) dose rate meter as shown in FIG. The PSF uses an optical fiber (plastic scintillator) as a gamma ray detector.Scintillation light emitted when gamma rays enter the PSF propagates through the optical fiber, and photodetectors installed at both ends of the optical fiber are used. The scintillation light is detected, and the position and intensity of the radiation are measured from the detection time difference of the scintillation light reaching each of the detectors at both ends of the optical fiber and the count rate of the incident light.

  One of the major features of the PSF is that the use of an optical fiber in the gamma ray detection section has high flexibility in the detector shape. Further, since the gamma ray detection position incident on the optical fiber can be specified, a wide range of dose rate measurement can be performed with one PSF having a length of several meters to several tens of meters.

  From the above, as shown in FIG. 1, the measurement of the air dose rate distribution according to the shape of the radioactive waste 1 can be performed at one time. Further, since the radioactive waste 1 has a certain size, it is measured by the dose rate distribution measuring device 3 having a plurality of radiation detectors as PSFs as shown in FIG. The rate distribution can be measured with high accuracy.

  In the first embodiment, a radiation detector using a plurality of PSFs is used. However, instead of using a plurality of PSFs, a single PSF may be used as a radiation detector.

  Further, the air dose rate distribution measuring device 3 in the present invention is preferably a PSF, but if the air dose rate distribution can be measured at a desired spatial resolution, for example, a measurement in which a plurality of plate-shaped plastic scintillators are arranged It may be a vessel.

  Return to FIG. Subsequent to step S10001, the dose rate distribution analysis / display device 10 creates air dose rate distribution information 30 of the radioactive waste 1 from the measured air dose rate distribution 20 (step S1002). For example, when a PSF is used as the air dose rate distribution measurement device 3, the PSF is a device that measures the dose rate at a position in the length direction of the optical fiber.

  FIG. 3 is a diagram showing an example of a measurement result by the PSF. The horizontal axis in FIG. 3 represents the length direction of the optical fiber, and the vertical axis represents the dose rate. In FIG. 3, there are a plurality of measurement results because, as illustrated in FIG. 1, a plurality of results are output when measurement is performed using a plurality of PSFs. The PSF measurement results show that the dose rate changes in the length direction as shown in FIG. 3. Therefore, when the PSF is arranged on the upper surface of the radioactive waste 1 as shown in FIG. Related position information for associating the positional relationship with the information is required.

  Similarly, when a plurality of PSFs are arranged for the radioactive waste 1 as shown in FIG. 1, related position information for associating the positional relationship between the radioactive waste 1 and each PSF is required. In this case, the method of arranging the PSF with respect to the radioactive waste 1 is determined in advance, the related position information is created, and the related position information is stored in the related position information storage device 9 so that the association is possible.

  The dose rate distribution analysis / display device 10 analyzes the air dose rate distribution of the radioactive waste 1 from the relevant position information read from the relevant position information storage device 9 and the measurement result of the air dose rate distribution measurement device 3, The resulting air dose rate distribution information 30 is displayed on the display screen.

  FIG. 4 is a diagram illustrating an example of a display screen 31 on which the analysis result of the air dose rate distribution information 30 is displayed on the screen of the dose rate distribution analysis / display device 10. FIG. 3 shows a display example of the air dose rate distribution information 30 when the radioactive waste 1 is virtually divided into 3 × 3 areas. After confirming the air dose rate distribution information 30 on the display screen 31, the operator presses a button illustrated on the display screen 31 to execute processing of steps described below.

  In FIG. 2, following step S1002, the concentration distribution high-speed condition generator 11 performs conversion from the air dose rate distribution information 30 to radioactivity distribution information or radioactivity concentration distribution information 40 (shown in FIG. 6) (step S1002). S1004). The conversion into the radioactivity distribution information or the radioactivity concentration distribution information 40 uses a conversion factor from the dose rate to the radioactivity concentration stored in the storage device 12 of the dose rate / radioactivity concentration conversion coefficient DB. The conversion factor is obtained in advance by a calibration test or the like from the relationship between the number of gamma ray photons (corresponding to radioactivity) of Co-60 or Cs-137 incident on the air dose rate distribution measuring device 3 and the air dose rate at the measurement position. The air dose rate distribution information 30 of the radioactive waste 1 is converted into radioactivity concentration distribution information 40 in advance. FIG. 5 is a view showing an example of a display screen 41 on which the converted radioactivity concentration distribution information 40 is displayed on a display unit of the concentration distribution constraint condition generation device 11.

  Next, when the operator operates the constraint condition generation button on the display screen 41, the concentration distribution constraint condition generation device 11 calculates the radioactivity concentration evaluation calculation to be performed in step S2002 described below from the radioactivity concentration distribution information 40. Is generated (step S1005).

  FIG. 6 is a diagram illustrating an example of generation of a constraint condition. As shown in FIG. 6A, the identifiers of the divided areas in the radioactivity concentration distribution information 40 are assigned in advance. Here, identifiers C1, C2,..., C9 are shown as examples. For this identifier, an adjacent area list 51 that indicates which identifier each divided area is adjacent to a divided area having which identifier is also prepared in advance. For example, as shown in FIG. 6B, the divided area C1 is expressed in a form such as “C1: C2, C4, C5” to indicate that it is adjacent to the divided areas C2, C4, C5. I do. This is generated for each divided area.

  In order to generate a constraint condition, a constraint condition list 52 is generated from the radioactivity concentration distribution information 40 and the adjacent area list 51. For example, as shown in FIG. 6 (C), since the density of the divided area C1 is higher than that of the divided area C2, it is expressed as “+ C2” as representing a higher density than C2. Since the density of the divided area C4 is substantially the same as that of the divided area C1, the density is set to “= C4”. Specifically, the constraint condition list 52 is described in an expression method such as “C1: + C2, = C4, + C5” (a condition that gives a relative magnitude relationship (including equivalence)).

  In addition, regarding the density equivalent to the focused divided region such as “= C4”, the error (precision) in the measurement is taken into consideration, and the density within the specified error range (the specification method is not shown) is the same as the density. Is required. A similar expression is performed for each divided area and described in the constraint condition list 52. The restriction condition list 52 is automatically generated by program processing or the like, which is convenient in operation.

  The constraint condition list 52 generated here is used as an input condition in the radioactivity concentration evaluation calculation performed in step S2002 described later. Here, in order to make a stronger constraint condition, the divided region of interest is a total of eight divided regions of four divided regions that are in contact with each side surface and four divided regions that are in contact with each vertex. However, for example, it is also possible to treat only four divided regions that are in contact with each side surface as adjacent divided regions.

  In FIG. 2, a step S3001 of storing the radioactive waste 1 in the radioactive waste container 5 is performed in parallel with or after the execution of the air dose rate distribution measuring step S1001. If the timing of execution of step S3001 is after execution of step S1001, it can be executed in parallel with steps S1002 to S1005.

  After performing Step S3001, the process proceeds to Step S2000 for performing gamma ray spectrum measurement and radioactivity concentration evaluation.

  In step S2000, first, the gamma ray energy spectrum 120 (shown in FIG. 1) of the radioactive waste 1 stored in the radioactive waste container 5 is measured by the gamma ray spectrum measuring device 4 (step 2001).

  FIG. 1 shows how the gamma ray energy spectrum 120 is measured by the gamma ray spectrum measuring device 4. FIG. 1 shows a case where a gamma ray spectrum measuring device 4 is arranged outside a radioactive waste container 5 containing a radioactive waste 1 and gamma rays from the radioactive waste 1 inside the radioactive waste container 5 are measured. Is shown. In the example shown in FIG. 1, a measurement example using a plurality of gamma ray spectrum measuring devices 4 is shown, but a single gamma ray spectrum measuring device 4 may be measured at a plurality of points at different locations. In any case, when the radioactive waste container 5 has a radioactivity concentration distribution or uneven distribution, it is necessary to measure the gamma ray spectrum 120 at a plurality of measurement points.

  In FIG. 2, after the measurement of the gamma ray spectrum 120, the in-vessel radioactivity concentration evaluation device 13 evaluates the radioactivity concentration of the radioactive waste 1 in the radioactive waste container 5 (step 2002). In evaluating the radioactivity concentration, it is conceivable to apply an imaging technique (image reconstruction technique) in a nuclear medicine diagnostic apparatus such as X-ray CT or PET / SPECT. However, in the measurement of radioactive waste, it is required that treatment and disposal, including measurement, be performed as quickly as possible. For this reason, in measurement, measurement cannot be performed at a sufficient measurement point as in the case of X-ray CT, and it may be required to evaluate the radioactivity concentration from data at a coarse measurement point number. In this case, there is a possibility that a highly accurate evaluation result cannot be obtained by simply applying the above-described image reconstruction technique as it is.

  In such a situation, in order to improve accuracy, there is a method of performing evaluation calculation by giving known information as a constraint condition in order to compensate for a shortage of data measurement points. Information that is known in advance may be referred to as prior information. This time, the density distribution constraint condition 21 generated in step S1005 is applied as the prior information. Further, since the image reconstruction technique used in X-ray CT requires data of a sufficiently large number of measurement points, it is not suitable as a method for evaluating the radioactivity concentration from data with coarse measurement points. In this case, a technique based on the successive approximation image reconstruction technique used as the imaging technique of the nuclear medicine diagnostic apparatus is more suitable.

  This method is based on a stochastic / statistical method such as Bayesian estimation. More specifically, the radioactivity concentration with the highest probability (the most likely solution) among a plurality of radioactivity concentration distributions from which the measurement data can be obtained under the condition that certain measurement data has been obtained. The distribution is updated for each small area such as a pixel or voxel that constitutes an image or a space, and when all the small areas have been completely updated, the same processing is performed in the next iteration. . The density distribution constraint condition 21 is applied to such a method.

  The specific application method is described below. First, the in-vessel radioactivity concentration evaluation device 13 refers to the constraint condition list 52 transmitted from the concentration distribution constraint condition generation device 11 for the divided region of interest. For example, when the identifier C1 shown in FIG. 6A is set as the region of interest, a line starting with “C1 ::” in the constraint condition list 52 shown in FIG. In this row, "C1: + C2, = C4, + C5" is described, so that among several radioactivity concentration distributions from which measurement data may be obtained, the concentration of C1 is higher than that of C2 and C5. The density distribution (a plurality of patterns can be considered) that is almost the same as C4 is narrowed down as the density distribution of the solution candidate, and the probability is evaluated only for these density distributions.

  That is, the density distribution that does not satisfy the density distribution constraint condition 21 is excluded from the calculation. Such processing is performed in all divided regions and all iterations. Further, as another method, without performing the above-described narrowing down, when calculating the probabilities for all the concentration distributions that are the solution candidates, the density distributions that do not satisfy the concentration distribution constraint condition 21 are calculated. There is a method of setting the probability to be small. By doing so, it is possible to prevent a local optimal solution in iterative calculation from falling.

  Further, the radioactivity concentration constraint condition may be a condition giving an absolute value of the radioactivity concentration. For example, instead of "C1: + C2, = C4, + C5", "C1: 1.5 * C2, 1.0 * C4, 1.5 * C5" can be used to give the absolute value of the radioactivity concentration. is there.

  By applying the density distribution constraint conditions 21 as described above, it can be expected that the calculation time can be reduced as compared with the calculation without the density distribution constraint conditions 21. In addition, in the iterative calculation, usually, the uniform density is often used as the initial condition of the calculation. However, by generating the initial condition of the density according to the density distribution constraint condition 21 described here, the number of repetitive calculations can be reduced. Therefore, the calculation time for the evaluation can be further reduced.

  Next, in FIG. 2, the evaluation result display device 14 displays the evaluation result (radioactive concentration of radioactive waste) in step S2002 (step S2003). Although the display result is not specifically illustrated here, for example, if the result is output to a text file or the like, the result can be used for screen display or listing of the result.

  According to the first embodiment of the present invention described above, even if the radioactive waste in the container has a radioactive concentration distribution or uneven distribution, it is possible to evaluate the radioactive concentration with high accuracy and in a short time. An object measuring device and a waste measuring method can be realized.

  That is, even when the radioactive waste contained in the rectangular container has a radioactive concentration distribution or uneven distribution, the radioactivity concentration can be evaluated with high accuracy. Further, by applying the constraint condition, the time required for the evaluation can be reduced. Further, by generating initial conditions for the concentration in the evaluation according to the constraint conditions, the time required for the evaluation can be further reduced.

  Although the above-described example is an example in which the radioactive waste 1 is virtually divided into nine regions, for example, the radioactive waste 1 can be divided into another number such as four regions, sixteen regions, and twenty-five regions. It is.

(Example 2)
Second Embodiment A second embodiment of the present invention will be described with reference to FIGS.

  FIG. 7 is an overall configuration diagram of the waste measurement device according to the second embodiment of the present invention. The second embodiment is an example of a configuration in which a decommissioning plan support system 501 and a waste information DB (database) storage device (a waste information storage device) 502 are added to the waste measurement device of the first embodiment.

  In FIG. 7, a decommissioning plan support system 501 is a system that supports a demolition plan of equipment and buildings during decommissioning of a nuclear power plant. The decommissioning plan support system 501 has, as one example, a database in which data such as a power plant operation history, an actually measured dose rate, a plant 3D model, and a demolition process are stored. Is generated.

  Data such as the power plant operation history described above and the processing results thereof are stored in the waste information DB storage device 502 as waste information for the radioactive waste 1.

  Examples of waste information include the location where radioactive waste 1 was installed at the time of the decommissioning plan for nuclear power plants, the purpose of use, operation history, the results of activation or contamination evaluation, shape, material, size at dismantling, etc. Is included.

  FIG. 8 is a diagram illustrating a measurement flow using the waste measurement device according to the second embodiment of the present invention. The difference between the measurement flow of the first embodiment shown in FIG. 2 and the measurement flow of the second embodiment shown in FIG. 8 is that, in the example of FIG. 8, between steps S1002 and S1004 shown in FIG. Step S1003 is added. Other steps are the same as those in the first and second embodiments.

  8, in step S1001, the air dose rate distribution 20 of the radioactive waste 1 before being stored in the radioactive waste container 5 is measured using the air dose rate distribution measuring device 3, and in step S1002, the dose rate distribution analysis is performed. The display device 10 creates the air dose rate distribution information 30 of the radioactive waste 1.

  Then, in step S1003, the concentration distribution constraint condition generation device 11 takes in the information of the radioactive waste 1 stored in the waste information DB storage device 502 via the decommissioning plan support system 501. Subsequently, in step S1004, the concentration distribution constraint condition generation device 11 performs conversion from the air dose rate distribution information 30 to radioactivity distribution information or radioactivity concentration distribution information 40. In the conversion to the radioactivity distribution information or radioactivity concentration distribution information 40, information on the radioactive waste 1 stored in the waste information DB storage device 502 is extracted and used.

  By using the information of the radioactive waste 1 described above, the accuracy of the conversion coefficient used in the conversion from the air dose rate distribution information 30 to the radioactivity distribution or the radioactivity concentration distribution information 40 in step S1004 is improved. Is possible.

  In the case of using a pipe as an example, by referring to the installation location and the purpose of use of the pipe (capturing information in step S1003), it is possible to identify whether the contamination due to radiation is on the outer surface or the inner surface of the pipe. When the gamma rays come from the inner surface of the pipe, the dose rate can be converted into the radioactivity concentration in consideration of the shielding effect of the pipe itself, so that the concentration conversion accuracy can be improved.

  Steps S1005, S2001 to S2003, and S3001 are performed in the same manner as in the first embodiment.

  The second embodiment of the present invention described above has the same effects as the first embodiment. Furthermore, according to the second embodiment, since the information on the radioactive waste 1 stored in the waste information DB storage device 502 is used to convert the radioactive waste 1 into the radioactivity distribution or radioactivity concentration distribution information 40, It is possible to evaluate the radioactivity concentration with higher accuracy.

  By using the waste measurement device or the waste measurement method of the present invention, for radioactive waste having various radioactivity concentration levels, in the case where the radioactive waste in the storage container has a radioactivity concentration distribution or uneven distribution. Even if it does, the radioactivity concentration can be evaluated with high accuracy.

  Further, the waste measurement device and the waste measurement method of the present invention, regardless of the shape of the container for radioactive waste, even if the radioactive waste in the container has a radioactive concentration distribution or uneven distribution, Radioactivity concentration can be evaluated with high accuracy.

  DESCRIPTION OF SYMBOLS 1 ... Radioactive waste, 2 ... Data collection device, 3 ... Air dose rate distribution measuring device, 4 ... Gamma ray spectrum measuring device, 5 ... Radioactive waste container, 9 ... Related Position information storage device, 10: dose rate distribution analysis / display device, 11: concentration distribution constraint condition generation device, 12: dose rate / radioactivity concentration conversion coefficient database storage device, 13: inside the container Radioactivity concentration evaluation device, 14 ... evaluation result display device, 20 ... air dose rate distribution, 21 ... concentration distribution constraint condition, 30 ... air dose rate distribution information, 31, 41 ... display Screen, 40: Radioactivity distribution or radioactivity concentration distribution information, 51: Adjacent area list, 52: Constraint condition list, 120: Gamma ray spectrum, 501: Decommissioning plan support system, 502 ... Storage of waste information DB Equipment (waste information storage device)

Claims (10)

A dose rate distribution measuring device for measuring the dose rate of radioactive waste,
A dose rate distribution analysis display device that creates air dose rate distribution information of the radioactive waste from the dose rate measured by the dose rate distribution measurement device ,
A dose rate activity concentration conversion coefficient database storage device that stores a conversion factor from the air dose rate distribution information created by the dose rate distribution analysis display device to the activity concentration,
The above air dose rate distribution information is converted into radioactivity or radioactivity concentration distribution using the above conversion factors stored in the above-mentioned dose rate radioactivity concentration conversion database storage device, and radioactivity or radioactivity concentration distribution constraint conditions are generated. Concentration distribution constraint condition generating device,
A gamma ray spectrum measuring device for measuring a gamma ray spectrum emitted from a radionuclide of the radioactive waste contained in the radioactive waste container,
A radioactivity concentration evaluation device in a container for evaluating the radioactivity concentration of the radioactive waste contained in the radioactive waste container from the gamma ray spectrum measured by the gamma ray spectrum measurement device and the radioactivity or radioactivity concentration distribution constraint conditions And
The waste measurement apparatus according to claim 1, wherein the radioactivity concentration distribution constraint condition is a condition that gives a relative magnitude relationship between radioactivity concentrations between regions obtained by virtually dividing the radioactive waste. The waste measuring device according to claim 1,
The above-mentioned dose rate distribution measuring device has a radiation detector using at least one plastic scintillation fiber. The waste measuring device according to claim 1,
A waste information storage device for storing information on the radioactive waste at the time of planning the decommissioning of the nuclear power plant; and the concentration distribution constraint condition generating device includes the radioactive waste stored in the waste information storage device. A waste measuring apparatus for extracting information on waste and generating the above-mentioned radioactivity concentration distribution constraint condition. The waste measuring device according to claim 1,
A waste measuring device further comprising an evaluation result display device for displaying a radioactive concentration of the radioactive waste evaluated by the radioactivity concentration evaluating device in the container. A dose rate distribution measuring device for measuring the dose rate of radioactive waste,
A dose rate distribution analysis display device that creates air dose rate distribution information of the radioactive waste from the dose rate measured by the dose rate distribution measurement device ,
A dose rate activity concentration conversion coefficient database storage device that stores a conversion factor from the air dose rate distribution information created by the dose rate distribution analysis display device to the activity concentration,
The above air dose rate distribution information is converted into radioactivity or radioactivity concentration distribution using the above conversion factors stored in the above-mentioned dose rate radioactivity concentration conversion database storage device, and radioactivity or radioactivity concentration distribution constraint conditions are generated. Concentration distribution constraint condition generating device,
A gamma ray spectrum measuring device for measuring a gamma ray spectrum emitted from a radionuclide of the radioactive waste contained in the radioactive waste container,
A radioactivity concentration evaluation device in a container for evaluating the radioactivity concentration of the radioactive waste contained in the radioactive waste container from the gamma ray spectrum measured by the gamma ray spectrum measurement device and the radioactivity or radioactivity concentration distribution constraint conditions When,
A waste information storage device for storing information on the radioactive waste at the time of planning the decommissioning of a nuclear power plant,
A waste measurement apparatus, wherein the concentration distribution constraint condition generation device generates the radioactivity concentration distribution constraint condition by extracting information on the radioactive waste stored in the waste information storage device. The waste measuring device according to claim 5,
The above-mentioned dose rate distribution measuring device has a radiation detector using at least one plastic scintillation fiber. The waste measuring device according to claim 5,
A waste measuring device further comprising an evaluation result display device for displaying a radioactive concentration of the radioactive waste evaluated by the radioactivity concentration evaluating device in the container. Measure the dose rate of radioactive waste,
Create air dose rate distribution information of the radioactive waste from the measured radioactive waste dose rate,
The conversion coefficient from the created air dose rate distribution information to the radioactivity concentration is stored in the dose rate radioactivity concentration conversion coefficient database storage device,
The above air dose rate distribution information is converted into radioactivity or radioactivity concentration distribution using the above conversion factors stored in the above-mentioned dose rate radioactivity concentration conversion database storage device, and radioactivity or radioactivity concentration distribution constraint conditions are generated. And
Containing the radioactive waste in a radioactive waste container,
Measure the gamma ray spectrum emitted from the radionuclide of the radioactive waste contained in the radioactive waste container,
A waste measurement method for evaluating the radioactive concentration of the radioactive waste contained in the radioactive waste container from the measured gamma ray spectrum and the radioactivity or radioactivity concentration distribution constraint conditions,
The method for measuring wastes, wherein the radioactivity concentration distribution constraint condition is a condition that gives a relative magnitude relationship of radioactivity concentrations between regions obtained by virtually dividing the radioactive waste. In the waste measuring method according to claim 8,
The radioactive waste information at the time of the nuclear power plant decommissioning plan is stored in the waste information storage device, the radioactive waste information stored in the waste information storage device is extracted, and the radioactivity concentration is extracted. A method for measuring waste, wherein a distribution constraint condition is generated. In the waste measuring method according to claim 8,
A method for measuring a waste, comprising displaying the radioactive concentration of the radioactive waste evaluated above.

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