JP6718683B2 - Radioactive waste measurement system and method - Google Patents

Description

The present invention relates to a radioactive waste measuring system and method for measuring radioactive waste generated with decommissioning of nuclear power generation facilities and the like in a short time and with high accuracy.

In the decommissioning of nuclear power generation facilities, a large amount of radioactive waste, such as radioactive waste and waste polluted by radioactivity, is generated when the facilities are dismantled. These wastes are required to be treated and disposed of according to the level of radioactivity concentration, so it is necessary to measure the radioactivity concentration. In measuring the radioactivity concentration, gamma rays emitted from gamma ray sources such as Co-60 and Cs-137 are the main targets.

Radioactive waste includes many devices such as pipes and valves. Depending on the system used, these devices may have a radiation source inside due to activation or contamination. When there is a radiation source on the inner surface of the equipment, gamma rays are attenuated depending on the material and plate thickness of the equipment. Therefore, it is necessary to consider the effect when evaluating the radioactivity concentration from the measurement results.

As a measuring method for avoiding the influence of gamma ray attenuation, there is a method described in Patent Document 1. In the method described in Patent Document 1, processing such as cutting and molding are performed so that the contaminated surface is exposed so that decontamination of an object and contamination measurement can be easily performed.

Specifically, for example, in the case of a pipe, the radioactive concentration is measured after the pipe is halved along the longitudinal direction to expose the inner surface to the front.

Further, as another method for evaluating the radioactivity concentration when there is a radiation source on the inner surface of the device, there is a method described in Patent Document 2. The method described in Patent Document 2 is evaluated by the following procedure.

First, a three-dimensional shape measuring device such as a three-dimensional laser scanner is used to acquire the three-dimensional spatial coordinates of the surface of the measurement target and create a three-dimensional model of the measurement target for Monte Carlo simulation. The positional relationship between this three-dimensional model and the model of the radiation detector of the radioactivity measuring apparatus configured for simulation is matched with the positional relationship between the actual measurement target and the actual radiation detector of the radioactivity measuring apparatus.

Using these models, the state of incidence of gamma rays emitted from the measurement object on the detector is simulated by Monte Carlo simulation. Then, the simulation result is compared with the gamma ray incident amount of the measured data to evaluate the radioactivity concentration.

JP, 2007-248066, A JP, 2006-84478, A

However, in the method described in Patent Document 1, a huge amount of demolition waste generated from a nuclear power generation facility or the like requires cutting or molding processing as a pretreatment for measurement, which is time-consuming and expensive. There is.

Further, in the method described in Patent Document 2, it is necessary to perform three-dimensional shape measurement, three-dimensional modeling, and Monte Carlo simulation each time a waste is received, and the time required from the waste reception to the measurement end Has the problem of becoming longer.

Further, in the three-dimensional surface shape measurement using a laser scanner or the like, there are limitations such that the shape of a region that is shaded and is not irradiated with laser cannot be measured, the inner surface shape cannot be measured, and the like. The problem is that it is difficult to model.

An object of the present invention is to realize a radioactive waste measuring system and method which can reduce the time required for the whole measurement and can evaluate the radioactivity concentration with high accuracy.

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

(1) In a radioactive waste measurement system, a waste information storage unit that stores waste information of waste that occurs when a nuclear facility is planned to be abandoned, and the waste information that has been stored in the waste information storage unit are called. , A three-dimensional modeling processing unit that creates a three-dimensional model of the waste based on the called waste information, a condition generation unit that generates a simulation condition that is a condition related to the source of the waste, and the three-dimensional model. The radiation simulation unit that executes the radiation distribution simulation using the three-dimensional model created by the conversion processing unit and the simulation condition created by the condition creating unit, and the radiation distribution simulation result executed by the radiation simulation unit. A conversion coefficient calculation unit that obtains a conversion coefficient that represents the relationship between the dose rate and the radioactivity concentration, a conversion coefficient storage unit that stores the conversion coefficient calculated by the conversion coefficient calculation unit in preprocessing, and radiation measurement A radiation detector that detects radiation in processing, a detector placement unit that calls the waste information stored in the waste information storage unit, and determines the placement of the radiation detector based on the waste information, A data collection unit that measures the surface dose rate of the waste by the radiation detector and collects surface dose rate data, the surface dose rate collected by the data collection unit, and the radiation measurement by the radiation detector. The conversion information stored in the conversion coefficient storage unit in the pre-processing performed prior to the processing is called, and a conversion unit for converting the surface dose rate to the radioactivity concentration is provided , and the waste information is place the waste had been established, the intended use, driving history, activation or contamination evaluation results, shape, Ru Oh in size when the material and demolition.

(2) In the radioactive waste measurement method, the waste information of the waste generated when the nuclear facility is planned to be abandoned is stored in the waste information storage unit, the stored waste information is called, and the called waste information is stored. Create a 3D model of the above waste based on
A simulation condition that is a condition related to the source of the waste is generated, a radiation distribution simulation is executed using the created three-dimensional model and the generated simulation condition, and a simulation result of the executed radiation distribution. Is used to obtain the conversion coefficient that represents the relationship between the dose rate and the radioactivity concentration, and the calculated conversion coefficient is stored in the conversion coefficient storage unit in advance processing, and the waste information storage unit is used in the radiation measurement processing. Calls the waste information accumulated in, determines the placement of the radiation detector based on the waste information, measures the surface dose rate of the waste by the radiation detector, and collects the surface dose rate data. , The collected surface dose rate and the conversion coefficient stored in advance in the conversion coefficient storage unit in the pre-processing performed prior to the radiation measurement processing by the radiation detector are called, and radiation is performed from the surface dose rate. A method for measuring radioactive waste, which is converted into active concentration, wherein the waste information is the location where the waste was installed, purpose of use, operation history, activation or pollution evaluation result, shape, material and dismantling time. Is the size of .

According to the present invention, it is possible to realize a radioactive waste measuring system and method capable of reducing the time required for the whole measurement and highly accurately evaluating the radioactivity concentration.

It is an operation|movement flowchart of the radioactive waste measuring system by Example 1 of this invention. 1 is a schematic configuration diagram of a radioactive waste measuring system according to a first embodiment of the present invention. It is explanatory drawing of the principal part of Example 2 of this invention. It is explanatory drawing of the principal part of Example 3 of this invention. It is a schematic block diagram of the radioactive waste measuring system by Example 4 of this invention. It is explanatory drawing of the method of arranging a plastic scintillation fiber dose rate meter according to the shape of a waste material. It is a schematic block diagram of the radioactive waste measuring system by Example 5 of this invention.

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

(Example 1)
FIG. 1 is an operation flowchart of the radioactive waste measuring system according to the first embodiment of the present invention, and FIG. 2 is a schematic configuration diagram of the radioactive waste measuring system according to the first embodiment of the present invention.

The present invention relates to disposal of waste associated with dismantling due to the abolition of nuclear facilities, and the examples described below are examples of disposal of radioactive waste in decommissioning of a nuclear power plant.

In FIG. 1, the radioactive waste measuring method according to the first embodiment of the present invention roughly includes steps S1000 and S2000 (shown by broken lines), and step S1000 is configured by the processes of steps S1001 to S1007. On the other hand, step 2000 includes the processes of steps S2001 to S2009.

Step S1000 does not necessarily have to be performed at the measurement stage, but is a pre-process that can be performed prior to the measurement. Step S2000 is a measurement process.

First, the processing flow of the preprocessing step S1000 will be described with reference to FIG.

As a preliminary process, the waste 10 is first selected from the waste information DB 2 (step S1001). The waste information DB2 (waste information storage unit) is a database that stores and stores waste information 10' about the waste 10 output from the decommissioning plan support system 1, as shown in FIG.

The decommissioning plan support system 1 is a system that supports a dismantling plan of equipment, buildings, etc. at the time of decommissioning (at the time of decommissioning) of a nuclear power plant. The decommissioning plan support system 1 has, as an example thereof, a database that stores data such as a power plant operation history, measured dose rate, plant 3D model, and dismantling process. From these data, calculation of radiation source distribution, equipment The cutting model is generated and the like. These data and their processing results are stored in the waste information DB 2 from the decommissioning plan support system 1 as the waste information 10 ′ for the waste 10.

Examples of the waste information 10' include the place where the waste 10 was installed, the purpose of use, the operation history, the activation or pollution evaluation result, the shape, the material, the size at the time of disassembly, and the like. An example of these is shown as waste information 10' in FIG.

Next, the three-dimensional modeling processing device 5 extracts the waste information 10' for the waste 10 from the waste information database 2 (step S1002).

Further, the three-dimensional modeling device 5 carries out a three-dimensional modeling process of the waste 10 from the extracted waste information 10' (step S1003). In the three-dimensional modeling, the waste information 10' such as shape, material and size is used. The three-dimensional model 11 is generated based on these pieces of information.

Then, the condition generation device 6 performs a simulation condition generation process for the three-dimensional model 11 based on the waste information 10' (step S1004). The condition generation device 6 has a concentration distribution condition generation unit 6-1 for generating a radiation source concentration distribution in the three-dimensional model. The simulation conditions performed by the condition generation device 6 include the nuclide serving as the radiation source, the position of the radiation source, the radiation source distribution, the type and arrangement of the radiation detector used in the measurement, and the like.

The nuclide is selected based on the operation history, activation or pollution evaluation results, etc. The position of the radiation source is also determined based on the operation history, the activation or pollution evaluation result, for example, whether it is on the inner surface or the outer surface of the waste 10, and the position of the radiation source is determined.

It is determined whether the radiation source position is the inner surface or the outer surface of the waste 10 in the case where there is a radiation source on the inner surface, whereas gamma rays are attenuated and scattered by the wall surface of the waste 10. This is because if there is a radiation source on the outer surface, there is no influence of attenuation or scattering of gamma rays.

The radioactivity concentration of the radiation source is different between when there is attenuation and scattering of gamma rays and when there are the same number of photons of gamma rays measured by the radiation detector. Therefore, it is necessary to specify in advance from the waste information 10' whether the influence is present or not in order to perform accurate measurement.

The radiation source distribution is generated based on the measured dose rate and the radiation source distribution calculation result. It is also possible to assume a radiation source having a uniform radioactivity concentration without a radiation source distribution or a point radiation source, but it is desirable to use the radiation source distribution as a simulation condition.

The simulation condition 9 is generated through the above processing. The type and shape of the radiation detector involved in the simulation are modeled in advance as a radiation detector model 27 according to the measuring device used. In this embodiment, as an example of the radiation detector 20 and the radiation detector model 27, a plastic scintillator capable of increasing the area is used.

The arrangement of the radiation detector (gamma ray detector) model 27 is determined based on the waste information 10 ′ or the three-dimensional model 11 generated by the three-dimensional modeling processing device 5.

Next, a simulation process is implemented (step S1005). The simulation processing step S1005 is performed by the radiation simulation apparatus 3. The simulation is performed after the three-dimensional model 11 generated by the three-dimensional modeling processing device 5 and the simulation condition 9 set by the condition generation device 6 are input to the simulation device 3.

A simulation method based on the Monte Carlo method is usually used for radiation simulation. In the Monte Carlo method, a large number of particles simulating alpha-ray particles, beta-ray particles (electrons), gamma-ray photons, and neutrons are generated, and the interaction with substances exhibiting stochastic behavior is calculated using pseudo-random numbers, and statistically calculated. Output the result of the dynamic processing.

As described in the background art, since the radiation targeted by the present invention is a gamma ray of Co-60 or Cs-137, the simulation apparatus 3 carries out a Monte Carlo simulation of the gamma ray.

Specifically, particles emitted from Co-60 and Cs-137 having gamma ray energy corresponding to each nuclide are generated from the radiation source position, and these particles undergo interactions such as attenuation and scattering by the wall of the pipe. , Simulate the number of gamma ray photons incident on the detector. The simulation results in the number of gamma-ray photons incident on the detector as a function of the radioactive concentration of the source, which gives a simulation of the distribution of the radioactive concentration.

Next, the calculation process of the conversion factor 5 from the dose rate to the radioactivity concentration is carried out (step S1006). The number of gamma ray photons incident on the detector obtained in the simulation processing step S1005 is input to the conversion coefficient calculation device 7, and the conversion coefficient calculation processing step S1006 is performed by the conversion coefficient calculation device 7.

In the gamma detector, the relationship between the number of gamma ray photons of Co-60 or Cs-137 incident on the radiation detector and the air dose rate at the measurement position is acquired in advance by a calibration test or the like, and the relationship is calculated by the conversion coefficient calculation device. 7 is input. The conversion factor calculation device 7 correlates the number of gamma ray photons incident on the detector with the radiation concentration of the radiation source obtained by the simulation and the dose rate of the detector, and the radiation concentration is calculated from the dose rate. A conversion coefficient 5 for converting into is calculated. The calculated conversion coefficient 5 is stored in the conversion coefficient DB 4 (step S1007).

The above simulation processing is performed at any time when the waste information 10′ of the waste 10 is confirmed in the decommissioning plan support system 1, and the conversion coefficient for converting the dose rate into the radiation concentration is stored in the conversion coefficient DB 4 in advance. By doing so, it is possible to calculate the radiation concentration using the conversion factor stored in the measured dose rate without actually performing a simulation process after actually measuring the waste, thus reducing the time required for the entire measurement. be able to.

In addition, for wastes of similar shape, since the conversion factor already stored can be used, it is not necessary to carry out a simulation before the measurement, so the time required for the whole measurement can be further reduced. it can.

Next, the processing step S2000 related to measurement will be described with reference to FIGS.

As the measurement process, first, a process of receiving the waste 10 in the measurement place and the measurement device is performed (step S2001).

Next, the waste 10 is selected from the waste information DB 2 (S2002), and the extraction information is extracted to extract the waste information 10' of the waste 10 and the simulation condition 9 (S2003). The waste information 10' and the simulation condition 9 extracted here are used to determine the arrangement of the radiation detector 20 in the measurement of gamma ray photons. In particular, it is necessary to arrange the gamma ray detector model 27 set in the simulation condition 9.

Next, the positioning process of the radiation detector 20 is performed (S2004). Positioning of the radiation detector 20 is performed based on the arrangement information of the radiation detector model 27 by the control device 31 which is a detector arrangement unit.

In the case of a plastic scintillator, which is an example of the gamma ray detector 20 of the present embodiment, it is assumed that the measurement is performed by approaching the waste 10 within a range that does not interfere with the waste 10 to be measured, as shown in FIG. ..

Further, the radiation detector 20 shown in FIG. 2 is a pair of detectors which are arranged so as to face each other with the waste 10 in between, which is a three-dimensional position of the gamma ray generation position of the waste. This is to enable identification.

After positioning the radiation detector 20, a surface dose rate measurement process is performed (S2005). The measurement data of the surface dose rate is collected by the data collection device 30.

After the measurement of the surface dose rate is completed, a measurement result output process is performed (S2006). The data collection device 30 includes a measurement result display screen (display unit) 41.

FIG. 2 shows an example of an output method of the measurement result 40, and shows a measurement result display screen (display unit) 41 that displays the measurement result 40 on the three-dimensional model 11 of the waste 10.

The measurement result shown in FIG. 2 represents the distribution of the surface dose rate, and the magnitude of the dose rate is indicated by the shade on the screen. It is also possible to display the magnitude of the dose rate by color.

Next, the conversion coefficient 5 stored in step S1007 is called from the conversion coefficient DB 4 (S2007), and the conversion result from the measurement result 40 to the radioactivity concentration 60 is executed using the called conversion coefficient 5. (S2008). The conversion processing step S2008 is executed by the conversion processing device 50. After performing the conversion processing step S2008, the radioactivity concentration 60 is output.

In the conventional technology, after performing step S2005 described above, it is necessary to perform a simulation on waste, calculate a conversion coefficient, and calculate the radioactivity concentration of the measured data. A whole lot of time was needed.

On the other hand, in the first embodiment of the present invention, as described above, before the actual radiation measurement, the conversion coefficient is calculated by performing simulation from the waste information according to the decommissioning plan, and stored as a database. ing. This eliminates the need for simulation processing after radiation measurement, and enables highly accurate processing of radioactive waste in a short time.

That is, according to the first embodiment of the present invention, it is possible to realize a radioactive waste measuring system and method capable of reducing the time required for the whole measurement and highly accurately evaluating the radioactivity concentration.

(Example 2)
Next, a second embodiment of the present invention will be described with reference to FIG. FIG. 3 is an explanatory diagram of a main part of the second embodiment of the present invention. The configuration other than the dose rate meter 22 is the same as the example shown in FIG. 2, and the preprocessing step and the measurement processing step are also the same as steps S1000 and S2000 shown in FIG. Detailed description is omitted.

In the second embodiment, the dose rate meter 22 is used as a radiation detector, and the surface of the waste 10 is scanned by the control device 31 or a separately provided scanning device (not shown). It shows an example of a method for measuring a dose rate.

For example, when the waste 10 is a cylindrical pipe as shown in FIG. 3, the dose rate meter 22 can be scanned in the longitudinal direction of the pipe and the dose rate can be measured at a plurality of points in the path.

Although FIG. 3 illustrates one scan in the axial direction of the pipe 10, the dose rate meter 22 is of course scanned in the circumferential direction of the pipe 10 so that the surface dose rate of the waste pipe 10 can be distributed all over the surface. Can be measured.

When the surface of the waste 10 is uneven, the information on the shape of the waste information 10′ or the three-dimensional model 11 is referred to, and the position of the dose rate meter 22 is set in the direction indicated by the double-headed arrow in FIG. Can be measured by scanning while controlling the distance from the surface of the waste 10 to be constant.

At this time, as the radiation detector model 27 used in the simulation apparatus 3, the radiation detector 20 used in the measurement is selected and implemented.

According to the second embodiment of the present invention, the same effect as that of the first embodiment can be obtained, and even with a small number of radiation detectors, the time required for the whole measurement can be reduced and the radioactive concentration can be evaluated with high accuracy. It is possible.

(Example 3)
Next, a third embodiment of the present invention will be described with reference to FIG. FIG. 4 is an explanatory diagram of a main part of the third embodiment of the present invention. This is an example of a method of using a dose rate meter 22 as a radiation detector, arranging a plurality of dose rate meters 22 on the surface of the waste 10, and measuring the dose rate at each point. The configuration other than the dose rate meter 22 is the same as that of the example shown in FIG. 2, and the preprocessing step and the measurement processing step are also the same as steps S1000 and S2000 shown in FIG. Detailed description is omitted.

As shown in FIG. 4, by disposing a plurality of dose rate meters 22 on the surface of the waste 10, the dose rate can be measured at a plurality of points. Further, as in the case of the second embodiment, when the surface of the waste 10 is uneven, the information regarding the shape of the waste information 10' or the three-dimensional model 11 is referred to and the direction indicated by the double-headed arrow in FIG. By controlling and arranging the position of the dose rate meter 22 in, it is possible to measure at a predetermined distance from the surface of the waste 10.

At this time, as the radiation detector model 27 used in the simulation apparatus 3, the radiation detector 20 used in the measurement is selected and implemented as in the second embodiment.

According to the third embodiment of the present invention described above, the same effect as that of the first embodiment can be obtained, and the radiation of the waste 10 can be measured at a plurality of points at the same time. It is possible to reduce the time and evaluate the radiation concentration with high accuracy.

(Example 4)
Next, a fourth embodiment of the present invention will be described with reference to FIGS. FIG. 5 is a schematic configuration diagram of a radioactive waste measuring system according to a fourth embodiment of the present invention. Example 4 is a system and method that uses a plastic scintillation fiber dose rate meter 21 as a radiation detector, arranges it on the surface of the waste 10, and measures the dose rate at multiple points.

The configuration other than the plastic scintillation fiber dose rate meter 21 is the same as the example shown in FIG. 2, and the preprocessing step and the measurement processing step are also the same as steps S1000 and S2000 shown in FIG. The detailed description thereof will be omitted.

The plastic scintillation fiber dose rate meter 21 uses an optical fiber (plastic scintillator) as a radiation detector, and scintillation light emitted when gamma rays enter the plastic scintillation fiber dose rate meter 21 inside the optical fiber. The detectors installed at both ends of the optical fiber detect the scintillation light, and the position and intensity of the radiation are determined from the detection time difference of the scintillation light reaching each detector at both ends of the optical fiber and the incident light count rate. Is measured.

One of the major characteristics of the plastic scintillation fiber dosimeter 21 is that the detector shape has high flexibility because an optical fiber is used for the radiation detecting section. Further, since the radiation detection position can be specified, one plastic scintillation fiber dose rate meter 21 can measure the dose rate at many points.

From the above, as shown in FIG. 5, the plastic scintillation fiber dose rate meter 21 can be flexibly arranged and measured according to the shape of the waste 10, and the measurement results of other points can be obtained as shown in the calculation result 40. It can be obtained with one measurement.

An example for arranging the plastic scintillation fiber dose rate meter 21 according to the shape of the waste 10 is shown in FIG.

In the example shown here, the plastic scintillation fiber dose rate meter 21 is attached to the flexible sheet 23 whose shape can also be freely changed, and the waste information 10 is arranged so as to be arranged according to the shape of the waste 10. Alternatively, the flexible sheet 23 is moved by a positioning mechanism (not shown) with reference to the three-dimensional model 11.

FIG. 6 is an explanatory diagram of a method of arranging the plastic scintillation fiber dose rate meter 21 according to the shape of the waste 10.

6A shows a state before the plastic scintillation fiber dose rate meter 21 is arranged according to the shape of the waste 10, and FIG. 6B is arranged according to the shape of the waste 10. It shows the latter state. As shown in (a) of FIG. 6, the flexible sheet 23 is two flat sheet-like sheets, but the cylindrical waste 10 is positioned between these two flat sheet-like flexible sheets 23, and the flexible sheet 23 shown in FIG. As shown in b), the two flat flexible sheets 23 can be formed into a cylindrical shape according to the surface shape of the cylindrical waste 10.

With this configuration, even if the waste 10 has a complicated shape, the surface dose rate can be measured with high accuracy. Further, when the waste 10 has a plate shape or a shape close to it, the waste 10 can be measured in the state shown in FIG. 6A, and therefore, the measurement can be performed according to the shape.

Also in the case of measurement by this method, as shown in FIG. 5, as the gamma ray detector model 28 used in the simulation apparatus 3, a model of the plastic scintillation fiber dose rate meter 21 is selected and the simulation is performed. ..

According to the fourth embodiment of the present invention, the same effect as that of the first embodiment can be obtained, and even if the shape of the waste 10 is complicated, the measurement can be performed without disassembling the device, so that the entire measurement can be performed. It is possible to evaluate the radioactivity concentration with high accuracy while reducing the time required for.

(Example 5)
Next, a fifth embodiment of the present invention will be described with reference to FIG. FIG. 7 is a schematic configuration diagram of a radioactive waste measuring system according to a fifth embodiment of the present invention. The fifth embodiment is a system and method for determining whether or not to perform the simulation processing step S1005 again using the measurement result 40 of the dose rate distribution.

Note that, here, an example in which the plastic scintillation fiber dose rate meter 21 is used as the gamma ray detector is shown, but the system and method described in Examples 1 to 4 can also be applied.

The possibility that the simulation result of the radioactivity concentration distribution by the simulation processing step S1005 and the measurement result 40 of the dose rate distribution may differ greatly cannot be denied.

For example, when it is assumed that the source 10 generated by the condition generator 6 is a point source or the source distribution is uniform, even though the actual waste 10 has a contamination or activation distribution, There may be cases where the simulation results differ significantly from the actual dose rate distribution.

Further, even when the result of the radiation source distribution calculated in the decommissioning plan support system 1 is different from the actual situation, it is considered that the simulation result and the actual dose rate distribution may be significantly different.

In such a case, by feeding back the measurement result 40 to the simulation condition and performing the simulation processing step S1005 again, it becomes possible to perform the simulation reflecting the actual situation, and it is possible to calculate the accurate conversion coefficient accordingly. Become.

Specifically, the measurement result 40 by the data collection device 30 and the simulation result by the simulation device 3 are input to the comparison processing unit 70, and the comparison processing unit 70 compares the measurement result 40 and the simulation result, and a certain value or more. Determine if there is a difference.

In the comparison processing unit 70, if the measurement result 40 and the simulation result are substantially equivalent, the comparison processing unit 70 notifies the simulation device 3 that they are equivalent, and the comparison coefficient stored in the conversion coefficient DB 4 is used. , The radioactivity concentration is calculated.

When the comparison processing unit 70 determines that the measurement result 40 and the simulation result are not substantially equivalent, the comparison processing unit 70 determines that the plastic scintillation fiber dose rate meter corresponding to the dose rate distribution of the measurement result 40. The distribution of the number of gamma ray photons measured at 21 is supplied to the condition generation device 6. The condition generation device 6 updates the source distribution condition based on the distribution of the number of gamma ray photons supplied from the comparison processing unit 70, newly generates the simulation condition 9, and inputs the simulation condition 9 to the simulation device 3 to perform the simulation. ..

The comparison processing unit 70 compares the result of the second simulation performed by the simulation apparatus 3 with the measurement result 40. As a result of the comparison, there may be a case where the difference between the result of the second simulation and the measurement result 40 is still large.

This may occur, for example, when the source distribution conditions updated based on the distribution of the number of gamma ray photons measured by the plastic scintillation fiber dose rate meter 21 do not completely simulate the actual distribution.

In this case, the radiation source distribution condition is updated again, the simulation condition 9 is regenerated, the simulation condition 9 is input to the simulation device 3, and the simulation is performed again. It is conceivable that such repetitive processing is repeatedly executed under a constraint condition such as required accuracy until it is satisfied.

The above simulation result is input to the conversion coefficient calculation device 7, the conversion coefficient 5 is recalculated, and stored in the conversion coefficient DB 4. Further, using the measurement result 40 and the recalculated conversion coefficient 5, the conversion processing device 50 outputs the radioactivity concentration 60 from the surface dose rate.

According to the fifth embodiment of the present invention, when the comparison result is compared by the comparison process 70 and the simulation result and the measurement result 40 are substantially the same, the simulation process after the radiation measurement is not necessary, and the simulation process is performed in a short time. In addition, the radioactive waste can be processed with high accuracy.

Further, when the comparison result is compared by the comparison process 70 and the simulation result and the measurement result 40 are not substantially the same, the simulation process is performed until the results are substantially the same, and the accurate conversion coefficient is calculated. It is possible to treat radioactive waste with high accuracy.

Here, the simulation result calculated by the simulation device 3 can also be displayed on the measurement result display screen 41.

By doing so, it becomes possible to compare the measurement result of the dose rate with the visual observation of the operator or the like.

Further, in the embodiment, the size of the dose rate is displayed on the measurement result display screen 41 in different shades and colors, but the surface dose rate data collected by the data collection device 30 should be displayed on the measurement result display screen 41. Can also

By doing so, the operator or the like can visually grasp the actual distribution of the dose rate.

Further, the radioactivity concentration 60 calculated by the conversion processing device 50 may be input to the data collection device 30, and the radioactivity concentration of the waste 10 may be displayed on the measurement result display screen 41.

By doing so, an operator or the like can visually grasp the actual radioactivity concentration of the waste 10.

In addition, the comparison processing unit 70 of the fifth embodiment can be configured to be included in the first to third embodiments.

As described above, according to the present invention, it is possible to reduce the time required for the whole measurement by reducing the pretreatment such as cutting and processing for radioactive wastes having various shapes, and to measure the radioactive concentration with high accuracy. Can be evaluated.

Although the above-described example is an example in which the present invention is applied to the decommissioning process of a nuclear power plant, the present invention is applicable not only to the nuclear power plant but also to other nuclear facilities.

1... Decommissioning plan support system, 2... Waste information DB, 3... Simulation device, 4... Conversion coefficient DB, 5... Three-dimensional modeling processing device, 6... Conditions Generation device, 6-1... Concentration distribution condition generation unit, 7... Conversion coefficient calculation device, 9... Simulation condition, 10... Waste, 10'... Waste information, 11... 3D model, 20... Gamma ray detector, 21... Plastic scintillation fiber dose rate meter, 22... Dose rate meter, 23... Flexible sheet, 27, 28... Gamma ray detector model, 30... Data collection device, 31... Control device, 40... Measurement result, 41... Measurement result display screen (display unit), 50... Conversion processing device, 60... Radioactivity concentration , 70... Comparison processing unit

Claims (19)

A waste information storage unit that stores waste information of waste generated at the time of a nuclear facility abolition plan,
A three-dimensional modeling processing unit that calls the waste information stored in the waste information storage unit and creates a three-dimensional model of the waste based on the called waste information;
A condition generation unit that generates a simulation condition that is a condition regarding the radiation source of the waste;
A radiation simulation unit that executes a radiation distribution simulation using the three-dimensional model created by the three-dimensional modeling processing unit and the simulation condition created by the condition creating unit;
Using the simulation result of the radiation distribution executed by the radiation simulation unit, a conversion coefficient calculation unit that obtains a conversion coefficient representing the relationship between the dose rate and the radioactivity concentration,
A conversion coefficient storage unit that stores the conversion coefficient calculated by the conversion coefficient calculation unit in preprocessing,
A radiation detector that detects radiation in radiation measurement processing,
A detector placement unit that calls the waste information stored in the waste information storage unit and determines the placement of the radiation detector based on the waste information;
A data collection unit that measures the surface dose rate of the waste by the radiation detector and collects the surface dose rate data,
The surface dose rate collected by the data collection unit and the conversion coefficient stored in advance in the conversion coefficient storage unit in the pre-processing performed prior to the radiation measurement processing by the radiation detector are called, and the surface A conversion unit that converts the dose rate into the radioactivity concentration,
Comprising a said waste information, where the said waste has been installed, the intended use, driving history, activation or contamination evaluation results, shape, radioactive waste, characterized in Oh Rukoto in size when the material and demolition Object measurement system. The radioactive waste measuring system according to claim 1,
The radiation detector is a radiation detector that measures the surface dose rate of the waste at at least two or more measurement points on the surface of the waste. The radioactive waste measuring system according to claim 2,
The radiation detector is at least one dose rate measuring device, and the detector disposing unit scans the dose rate measuring device in the vicinity of the surface of the waste, a radioactive waste measuring system. .. The radioactive waste measuring system according to claim 2,
The said radiation detector is at least 2 or more dose rate measuring devices, The radioactive waste measuring system characterized by the above-mentioned. The radioactive waste measuring system according to claim 2,
The radioactive waste measuring system according to claim 1, wherein the radiation detector has at least one plastic scintillation fiber. The radioactive waste measuring system according to any one of claims 1 to 5,
The detector arrangement unit extracts the radioactive concentration distribution of the waste from the waste information and inputs it to the condition generation unit, and the condition generation unit generates the radiation source concentration distribution in the three-dimensional model. A radioactive waste measuring system having a concentration distribution condition generating unit. The radioactive waste measuring system according to any one of claims 1 to 5,
The radiation distribution of the surface dose rate collected by the data collection unit and the radiation distribution of the radiation simulation unit are compared, and the radiation distribution of the surface dose rate collected by the data collection unit and the radiation simulation unit are compared. If the radiation distribution is not substantially equivalent, the radiation distribution of the surface dose rate collected by the data collection unit is further provided with a comparison processing unit for inputting to the condition generation unit, and the radiation distribution unit for re-simulation is performed by the above-mentioned radiation simulation unit. A radioactive waste measurement system characterized in that a simulation is performed and the conversion coefficient is calculated again by the conversion coefficient calculation unit. The radioactive waste measuring system according to any one of claims 1 to 5,
The radioactive waste measurement system, wherein the data collection unit includes a display unit, and displays a radiation distribution simulation result executed by the radiation simulation unit on the display unit. The radioactive waste measuring system according to any one of claims 1 to 5,
The above-mentioned data collection part is provided with a display part, and the data of the above-mentioned surface dose rate which the above-mentioned data collection part collected is displayed on the above-mentioned display part, The radioactive waste measurement system characterized by the above-mentioned. The radioactive waste measuring system according to any one of claims 1 to 5,
The radioactive waste measurement system, wherein the data collection unit includes a display unit, and the radioactivity concentration converted by the conversion unit is displayed on the display unit. Accumulate waste information of waste generated at the time of abolition planning of nuclear facilities in the waste information accumulation section,
Calling the accumulated waste information, creating a three-dimensional model of the waste based on the called waste information,
Generate a simulation condition that is a condition related to the source of the waste,
A radiation distribution simulation is executed using the created three-dimensional model and the generated simulation conditions,
Using the simulation result of the radiation distribution performed above, find the conversion factor that represents the relationship between the dose rate and the radioactivity concentration,
Store the calculated conversion factor in the conversion factor storage unit in advance processing,
The waste information stored in the waste information storage unit in the radiation measurement process is called, and the placement of the radiation detector is determined based on the waste information.
Measure the surface dose rate of the waste with the radiation detector, collect the surface dose rate data,
The collected surface dose rate and the conversion coefficient stored in advance in the conversion coefficient storage unit in the pre-processing performed prior to the radiation measurement processing by the radiation detector are called, and the radioactivity is calculated from the surface dose rate. A radioactive waste measurement method for converting to concentration ,
The said waste information is the place where the said waste was installed, the purpose of use, the operation history, the activation or pollution evaluation result, the shape, the material, and the size at the time of dismantling, and the radioactive waste measuring method. The radioactive waste measuring method according to claim 11,
A radioactive waste measuring method, wherein the radiation detector is a radiation detector that measures the surface dose rate of the waste at at least two or more measurement points on the surface of the waste. The radioactive waste measuring method according to claim 12,
The said radiation detector is at least 1 or more dose rate measuring device, The said dose rate measuring device is made to scan the surface vicinity of the said waste, The radioactive waste measuring method characterized by the above-mentioned. The radioactive waste measuring method according to claim 12,
The said radiation detector is at least 2 or more dose rate measuring devices, The radioactive waste measuring method characterized by the above-mentioned. The radioactive waste measuring method according to claim 12,
The said radiation detector has at least 1 or more plastic scintillation fiber, The radioactive waste measuring method characterized by the above-mentioned. The radioactive waste measuring method according to any one of claims 11 to 15,
By comparing the collected radiation distribution of the surface dose rate with the radiation distribution obtained by the radiation simulation, the collected radiation distribution of the surface dose rate is not substantially equal to the radiation distribution obtained by the radiation simulation. In this case, the radioactive waste measurement method is characterized in that the radiation simulation is performed again and the conversion coefficient is obtained again. The radioactive waste measuring method according to any one of claims 11 to 15,
A method for measuring radioactive waste, characterized in that the result of the radiation distribution simulation executed above is displayed on a display unit. The radioactive waste measuring method according to any one of claims 11 to 15,
A method for measuring radioactive waste, comprising displaying the collected data of the surface dose rate on a display unit. The radioactive waste measuring method according to any one of claims 11 to 15,
A method for measuring radioactive waste, comprising displaying the converted radioactivity concentration on a display unit.

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