KR102071049B1 - Calibration method of non-destructive assay for overpact drum containing compacted drums - Google Patents

Abstract

The present invention relates to a calibration method of a nuclide analysis apparatus. More specifically, the present invention relates to the calibration method of the nuclide analysis apparatus for improving accuracy of nuclide analysis of a multi-embedded drum, in which calibration is performed by calculating calibration values using a calibration source, a projection source, a semiconductor detector, and a calibration aid to accurately perform the nuclide analysis of the multi-embedded drum in the nuclide analysis apparatus.

Description

CALIBRATION METHOD OF NON-DESTRUCTIVE ASSAY FOR OVERPACT DRUM CONTAINING COMPACTED DRUMS}

The present invention relates to a method for calibrating a nuclide analysis device, and more specifically, by using a calibration source, a projection source, a semiconductor detector, and a calibration aid to accurately perform nuclide analysis of multiple internal drums in a nuclide analysis device. The present invention relates to a method of calibrating a nuclide analysis device for improving the accuracy of nuclide analysis of a multi-embedded drum.

In order to request permanent disposal of low and medium level radioactive waste (hereinafter referred to as waste) permanent disposal, the nuclear stock of the waste drum must be measured in accordance with the relevant laws and regulations.

Individual stocks are essential information for limiting the total radioactivity of the drums to be stored so as not to exceed the storage limit of the permanent disposal repository, and continuously manage the safety of the permanent disposal repository.

The nuclear stock of the shield drum can be measured directly by using a nuclide analyzer for nondestructive spectroscopy using a high resolution semiconductor detector.

In addition, the waste packaging container was limited to a 200 L drum or a 320 L repacking drum, which is a standard container due to compatibility problems with a transport container, a transport handling equipment, a disposal container, and an analysis container of a drum nuclide analysis device.

Generally, one 200 L drum is repacked in a 320 L repackaging container as shown in the left side of FIG. 1.

However, in Korea, two or more 200 L drums of ultra high pressure compression were repacked in a 320 L container as shown in FIG.

Currently, the nuclide analysis device is designed to measure the case of repacking one 200L drum in a 320L repackaging container, and a calibration procedure and a calibration drum were designed according to this design. For this reason, when two or more 200 L drums are repacked in a 320 L container, they are different from the measurement geometry of the current calibration (container shape). Therefore, a new calibration method is required to improve measurement accuracy.

The present invention is to meet the above requirements, the nuclide analysis for improving the nuclide analysis accuracy of the multi-embedded drum to calibrate the nuclide analysis device to be measured by repackaging two or more 200ℓ drum in 320L repackaging container Its purpose is to provide a calibration method for the device.

Features of the present invention for achieving the above object,

Nuclide analysis for nondestructive spectroscopy using a high resolution semiconductor detector for the nuclide analysis of a single-packed drum with one or two 200L packed drums and a multi-packed drum with three or more 200L packed drums A method of calibrating a device, comprising: a first calibration aid, the first calibration aid being six standard 200L calibration drums inserted with calibration sources within the expiration date and empty or of different media having different densities; The upper and lower parts are opened to shield the upper and lower parts, and have a compression thickness effect of the plurality of built-in drums, and 320 L of empty hollows for inserting the second calibration aid and the first and second calibration aids, which are calibration drums overlaid on the first calibration aid. Check for non-contamination of the third calibration aid, calibration drum, perform decontamination if contaminated, actual 200ℓ spinning required for calibration verification test A calibration necessity check step of selecting a reference radioactive waste drum among the waste waste drums; A hardware checking step of aligning the projection source of each layer and the semiconductor detector; A software checking step of changing to a nuclide library composed of nuclides of a calibration source and setting software in units of measurement for calculating efficiency of the semiconductor detector, which is a calibrator; An energy calibration and shape calibration step of the semiconductor detector which performs energy calibration and shape calibration of the semiconductor detector by using a spectrum obtained by shooting a projection source; In order to calculate the dead time correction coefficient (R _ck ) during the repackaging drum analysis, after inputting a signal having a specific energy into the semiconductor detector at a specific counting rate, the initial counting rate (C ₀ ) of the reference pulse measured at the minimum radiation level is measured. A reference pulse calibration step of measuring; Calibration value calculation step of calculating the respective calibration values to perform projection source measurement and calibration or multi-efficiency measurement and calibration according to the density of the repacking drum to compensate for radiation attenuation by the medium in the repackaging drum analysis Wow; A calibration result input step of inputting a calibration value calculated in the software; A calibration check test step of verifying validity of a calibration by performing an absolute check test or a relative check test when the input calibration value is a plurality of internal drums; And when the calibration is completed, it is characterized by consisting of a calibration complete step of operating by switching to the operating state.

Wherein each medium of the first calibration aid is Foam, Homosote, Particle Board, Sand, Concrete + Iron Powder, and each of the first calibration aids Density (g / cc) is 0, 0.02, 0.44, 0.71, 1.66, 3.02.

Here, the second calibration aid may have an upper and lower openings so as to cover the first calibration aid, and have a thickness having an effect of 3 to 5 compression thicknesses of the compression drum of the multi-embedded drum, and within the first calibration aid. It shields the source and is mounted in the center of the third calibration aid.

Here, the energy calibration and shape calibration steps of the semiconductor detector may be adjusted so that the minimum / maximum gamma ray energy corresponding to the minimum / maximum channel of the semiconductor detector reacts, and the correlation between the reaction channel of the semiconductor detector and gamma ray energy. Determining (energy correction) and determining the correlation between the measured half width of the semiconductor detector and gamma ray energy (shape correction), but only once, regardless of the measurement geometry and the type of repacking drum.

Here, the reference pulse calibration step measures the initial counting rate (C ₀ ) of the reference pulse at a level that minimizes the radiation level for calculating the dead time correction coefficient (R _ck ) during drum analysis.

Here, when the calibration value calculation step is less than the reference density and the single built-in drum, the first calibration aid, which is an empty container without a calibration source, is mounted at the center of the third calibration aid, and the third calibration aid is Shoot the projection source for each layer divided equally into eight in the height direction and determine the initial count rate (SR _ik ⁰ ) without media attenuation from the spectrum measured by the semiconductor detector, and layer 9 is the spectrum obtained from layers 1-8. Is defined as the summation spectrum summed for each channel, and the initial counting rate (SR _i9 ⁰ ) of layer 9 is calculated using the summation spectrum.

Here, if the calibration value calculation step is less than the reference density and the multi-integrated drum, the second calibration aid is overlaid on the first calibration aid, which is an empty container with no calibration source, and then centered on the third calibration aid. Mounted in the laser beam, and the projection source is taken for each layer divided into eight equal parts in the height direction to determine the initial count rate (MR _ik ⁰ ) without medium attenuation from the spectrum measured by the semiconductor detector. The layer is defined as a summation spectrum obtained by summing the spectra acquired from layers 1 to 8 for each channel and using this, calculates the initial count rate (MR _i9 ⁰ ) of layer 9.

)을 1~9번 레이어별로 계산하고, 9번 레이어의 효율을 이용하여 교정값인 밀도 증가에 따른 효율 감소비(CF(E,ρ))를 계산한다.Here, in the step of calculating the calibration value, the semiconductor detector may be mounted in the center of the third calibration aid by mounting each of the six first calibration corrections in which the calibration source and the medium are inserted in the case of a single internal drum having a reference density or more. Repeatedly measuring the efficiency of each layer 1 to 9 to obtain efficiency calibration curves for six densities, and the efficiency of the semiconductor detector for each density and gamma ray energy (

) Is calculated for each layer 1-9, and the efficiency reduction ratio (CF (E, ρ)) according to the density increase, which is a calibration value, is calculated using the efficiency of layer 9.

)을 계산한다.Here, in the step of calculating the calibration value, the second calibration aid is overlaid on the first calibration corrector which is 0 g / ㏄ with no calibration source and medium in the case of a multi-embedded drum that is greater than or equal to the reference density. Calculate the efficiency calibration curve by repeatedly measuring the efficiency of the semiconductor detector for each layer 1 to 9 by mounting at the center of the circuit, and applying the efficiency reduction ratio CF (E, ρ) according to the density increase of the single internal drum Efficiency of the semiconductor detector according to layer 1, layer 9, density, and gamma ray energy for the drum (

Calculate

Here, the calibration verification test step may be performed using a calibration source, the first calibration aid, the second calibration aid, and a third calibration aid in the case of an absolute verification test, and the reference waste drum in the relative verification test. The second calibration aid is overlaid and mounted at the center of the third calibration aid and analyzed to see if it has the same result as the measurement result measured under the other measurement geometry.

According to the calibration method of the nuclide analysis apparatus for improving the nuclide analysis accuracy of the multi-embedded drum of the present invention configured as described above, the calibration value is calculated by using a calibration source, a projection source, a semiconductor detector, and a calibration aid. Nuclide analysis of multiple internal drums can be performed accurately in the nuclide analysis device.

1 is a diagram comparing the current calibration measurement structure and the 320 L multi-embedded drum shape.
2 is a flow chart illustrating a calibration method of a nuclide analysis device for improving the nuclide analysis accuracy of a multi-embedded drum according to the present invention.

Hereinafter, a method of calibrating a nuclide analysis device for improving nuclide analysis accuracy of a multi-embedded drum according to the present invention will be described in detail with reference to the accompanying drawings.

In the following description of the present invention, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted. Terms to be described later are terms defined in consideration of functions in the present invention, and may be changed according to intentions or customs of users or operators. Therefore, the definition should be made based on the contents throughout the specification.

1 and 2, a calibration method of a nuclide analysis device for improving the nuclide analysis accuracy of a multi-embedded drum according to the present invention is a calibration necessity check step (S10), hardware check step (S20), software check step (S30), the energy calibration and shape calibration step (S40) of the semiconductor detector, the reference pulse calibration step (S50), the calibration value calculation step (S60), the calibration result input step (S70), the calibration confirmation inspection step (S80) and the calibration complete step (S90).

<< calibration necessity inspection step -S10 >>

First, a calibration source (standard certified material) within the expiration date is inserted, and the first calibration aid and the first calibration aid are six standard 200L calibration drums with empty or different media inserted to have different densities. A second calibration aid, which is a calibration drum overlaid on the first calibration aid, and a calibration drum into which the first and second calibration aids are inserted, having the upper and lower portions opened to shield and having the effect of the compression thickness of the multi-embedded drum. Check for non-contamination, perform decontamination if contaminated, and select a reference waste drum from the actual 200ℓ waste drums required for calibration verification. In this case, each medium of the first calibration aid is foam, homosote, particle board, sand, concrete + iron powder, and each density of the first calibration aid is g / dL) is 0, 0.02, 0.44, 0.71, 1.66, 3.02. At this time, the second calibration assistant has a top and bottom opening to have a structure that is coupled to the first calibration assistant, and has a thickness corresponding to the compression thickness (from three to five compression drums) of the multi-embedded drum and It shields the source and has a feature that can be mounted in the center of the third calibration aid.

In addition, the selection of the reference waste drum is a well-known domestic patent registration publication No. 10-0979559 (Calibration verification test method for maximizing the period of use of the standard radioactive material retrieval and reference radioactive waste drum for indirect calibration validation )

<< hardware check step-S20 >>

Then, the alignment of the projection source and the semiconductor detector for each layer (measurement height) of the nuclide analyzer is performed. That is, the alignment operation is performed when necessary so that the drum incident trajectory of the projection source of each layer is located at the center of the detector while being perpendicular to the drum height direction, and the measurement geometric setting constant confirmation or factory setting is restored.

<< software check step-S30 >>

) 계산을 위한 측정 단위(예 : μCi)로 핵종분석장치의 소프트웨어를 설정한다.Subsequently, it is changed to a nuclide library composed of nuclides of the calibration source, and the efficiency of the semiconductor detector serving as the calibrator (

Set the software of the nuclide analyzer to the unit of measurement (eg μCi) for the calculation.

<< Energy Calibration and Shape Calibration Step-S40 of Semiconductor Detector >>

Subsequently, energy calibration and shape (half-width) calibration of the semiconductor detector is performed using the spectrum obtained by shooting the projection source.

At this time, the minimum / maximum gamma-ray energy corresponding to the minimum / maximum channel of the semiconductor detector is adjusted to respond, and the correlation (first-order) of the reaction channel and the gamma-ray energy of the semiconductor detector is determined (energy correction), and the The correlation between the measured half width and the gamma ray energy is determined (shape corrected), but only once, regardless of the measurement geometry and the type of repacking drum.

<< reference pulse calibration step -S50 >>

Once the energy calibration and shape calibration of the semiconductor detector is completed, a signal with a specific energy (typically energy outside the analysis range of the drum) for the calculation of the dead time correction factor (R _ck ) in the repackaging drum analysis is given a specific counting rate (eg 1000 CPS). After inputting to the semiconductor detector, measure the initial counting rate (C ₀ ) of the reference pulse measured at the minimum radiation level (e.g., all the shields are closed and the minimum dead time of the semiconductor detector).

<< calibration value calculation step-S60 >>

In order to compensate for radiation attenuation by the medium during repackaging drum analysis, each calibration value is calculated to perform projection source measurement and calibration or multi-efficiency measurement and calibration depending on the density of the repackaging drum.

That is, when the repacking drum is less than the reference density and is a single drum, the first calibration aid, which is an empty container with no calibration source, is mounted at the center of the third calibration aid, and the third calibration aid is divided equally into eight in the height direction. By shooting the projection source for each divided layer to determine the initial counting rate (SR _ik ⁰ , where k = 1, 2, 3, ..., layer 9) without the media attenuation by the spectrum measured by the semiconductor detector. Layer 9 is defined as the summation spectrum obtained by summing the spectra acquired from each layer from layer 1 to layer 8 for each channel, and calculates the initial counting ratio SR _i9 ⁰ of layer 9 using this.

In the case where the drum is less than the reference density and the multi-integrated drum, the second calibration assistant is overlaid on the first calibration assistant, which is an empty container, in which the calibration source is not installed. The projection source is taken for each layer divided into eight evenly, and the initial count rate MR _ik ⁰ without medium attenuation is determined from the spectrum measured by the semiconductor detector. Layer 9 is defined as the summation spectrum obtained by summing the spectrums acquired from layers 1 to 8 for each channel, and calculates the initial counting ratio (MR _i9 ⁰ ) of layer 9 using this.

Conversely, if the repacking drum is above the reference density and is a single-built drum, the calibration source (six standard certified materials) is placed at the location specified in the first calibration aid and mounted at the center of the third calibration aid to improve the efficiency of the semiconductor detector. Measure by layer.

This procedure is repeated for six calibration drums.

)은 레이어마다 아래의 수학식 1에 따라 계산한다. 9번 레이어의 경우, 1~8번 레이어까지 취득한 스펙트럼을 각 채널별로 합산한 합산 스펙트럼으로 정의하고 이를 이용하여 9번 레이어의 반도체 검출기의 효율(

)을 수학식 2로 계산한다. Therefore, efficiency calibration curves for six densities are obtained, and the efficiency of semiconductor detectors by density and gamma ray energy (

) Is calculated according to Equation 1 below for each layer. In case of layer 9, the spectrum acquired from layers 1 to 8 is defined as the summation spectrum which is added up for each channel, and the efficiency of the semiconductor detector

) Is calculated by Equation 2.

Where S: single built-in drum

: 레이어 k에서 측정기하 NOW로 측정한 밀도별, 감마선 에너지별 반도체 검출기의 효율

: Efficiency of Semiconductor Detector by Density and Gamma Ray Energy Measured by Measurement Geometry NOW in Layer k

E: Gamma-ray energy of standard certified material (e.g. 275, 302, 383, 661, 1173, 1332 keV)

ρ: density of the calibration drum (e.g. 0, 0.02, 0.44, 0.71, 1.66, 3.02 g / g)

: 단일내장 드럼 반도체 검출기의 효율 계산을 위해 레이어 k에서 취득한 감마선 에너지 E와 교정용 드럼 밀도(ρ)에 대한 계수율(C/s)

: Counting ratio (C / s) of gamma-ray energy E obtained from layer k and calibration drum density (ρ) for the calculation of the efficiency of a single-embedded drum semiconductor detector

: 표준인증물질에서 방출하는 감마선 에너지 E의 단위 시간당 감마선 방출수(Gamma/s)

: Number of gamma rays emitted per unit time of gamma-ray energy E emitted by standard certified substances (Gamma / s)

Where R _ck is the dead time correction factor of the spectrum obtained from layer k to calculate the efficiency of the current semiconductor detector.

C ₀ : Initial counting rate of reference pulse when detector dead time is lowest

λ: Decay constant of isotope when reference pulse is used as isotope (source) (λ = 0 when using reference pulser (device))

T _m -T ₀ : Elapsed time after calibration of the reference pulse until acquisition of the spectrum requiring current dead time correction

C _m : Counting rate of the reference pulse measured in the spectrum requiring dead time correction

)을 이용하여 밀도 증가에 따른 단일내장 드럼용 효율 감소비(CF(E,ρ))를 아래의 수학식 3에 따라 계산한다.Then, the efficiency of the semiconductor detector of layer 9 (summing up) for a single built-in drum (

Calculate the efficiency reduction ratio (CF (E, ρ)) for a single built-in drum with increasing density using the following equation.

)을 아래의 수학식 4를 통해 레이어별 측정한다.In addition, in the case of more than one built-in drum with a reference density or more, the calibration source is left at the designated position on the calibration drum of 0g / ㏄ of the first calibration aid, and is overlaid with the second calibration aid, and then mounted on the center of the third calibration aid to 0g. Efficiency of Semiconductor Detectors for Multi-embedded Drums

) Is measured for each layer through Equation 4 below.

Where M: multi-built drum

: 레이어 k에서 측정기하 NOW로 측정한 0g/㏄ 밀도의, 감마선 에너지별 반도체 검출기의 효율

: Efficiency of Gamma-ray Energy-Specific Semiconductor Detectors Measured by Geometry NOW at Layer k

E: Gamma-ray energy of standard certified material (e.g. 275, 302, 383, 661, 1173, 1332 keV)

R _ck is the dead time correction factor of the spectrum obtained from layer k to calculate the efficiency of the current semiconductor detector.

: 다수내장 드럼 반도체 검출기의 효율 계산을 위해 레이어 k에서 취득한 밀도 0 g/㏄의 감마선 에너지별 계수율(C/s)

: Counting ratio (C / s) of gamma ray energy of density 0 g / ㏄ obtained from layer k for efficiency calculation of multi-embedded drum semiconductor detector

: 표준인증물질에서 방출하는 감마선 에너지 E의 단위 시간당 감마선 방출수(Gamma/s)

: Number of gamma rays emitted per unit time of gamma ray energy E emitted by standard certified substances (Gamma / s)

)을 결정한다.At this time, if the total radiation of the calibration source is above a certain level, a separate license for handling is required. On the other hand, when a calibration source having a radiation below a certain level is mounted on a drum having a high density and the outer wall thickness of the container, a sufficient coefficient cannot be secured within a reasonable measurement time. Therefore, it is preferable to use the calculation method rather than the direct measurement method to determine the efficiency of the semiconductor detector. The efficiency calculation method of the semiconductor detector is based on the efficiency of the semiconductor detector (Equation 5) for the measurement geometry of the empty container ((0g / ㏄)) with a thick outer wall thickness, and the efficiency reduction ratio for the increase in density of a 200 L drum with a thin outer wall thickness ( CF (E, ρ) Equation 4) is separately measured and calculated in accordance with Equation 5 below by combining them. This allows the multiple efficiencies of the semiconductor detectors of

Is determined.

Where E is the gamma ray energy of the standard certified substance (e.g. 275, 302, 383, 661, 1173)

ρ: density of the calibration drum (e.g. 0, 0.02, 0.44, 0.71, 1.66, 3.02 g / g)

k: 1, 2, 3,... , Layer 9

<< calibration result input step-S70 >>

Enter the calculated calibration value into the software.

<< calibration confirmation inspection step-S80 >>

When the calibration value input in the calibration result input step (S70) is a single internal drum, it is performed through a calibration check test disclosed in the well-known Korean Patent Registration Publication No. 10-0979559.

On the other hand, in the case of a multi-embedded drum, the validity of the calibration is verified by performing a calibration check test using an absolute check or a relative check test.

In the case of multiple internal drums, a calibration verification test is performed by using an absolute verification test or a relative verification test. In the absolute verification test, a calibration source (standard certified material) and a first calibration aid (0.5 g / ㏄ of 6) are performed. 1 calibration drum), 2nd calibration aid, and 3rd calibration aid (hereinafter pass rate is within 10%).

In the case of the relative confirmation test, a second calibration aid is overlaid on the actual radioactive waste drum (200ℓ) which has been subjected to the relative verification test according to the known domestic patent registration publication No. 10-0979559, mounted on the center of the third calibration aid, and analyzed. Check the calibration result of the efficiency of the semiconductor detector of the multi-embedded drum by confirming that it has the same result as the measurement result measured in other measurement geometry. (The pass criterion is within 20% of the first relative confirmation test and the second relative confirmation test. Is within wh 30%)

<< calibration completion phase-S90 >>

Once the calibration is validated and converted to operational status (change to operational nuclide library, change to operational radioactivity unit (eg MBq)).

As those skilled in the art would realize, the described embodiments may be modified in various ways, all without departing from the spirit or scope of the present invention. It is to be understood, however, that the present invention is not limited to the specific forms referred to in the description, but rather includes all modifications, equivalents and substitutions within the spirit and scope of the invention as defined by the appended claims. Should be.

Claims (8)

Nuclide analysis for nondestructive spectroscopy using a high resolution semiconductor detector for the nuclide analysis of a single-packed drum with one or two 200L packed drums and a multi-packed drum with three or more 200L packed drums In the calibration method of the device,
A first calibration aid, six standard 200 l calibration drums, with a calibration source within the expiration date inserted, empty or with different media for different densities, and an upper and lower opening to shield the first calibration aid. A third calibration aid having a compression thickness effect of the plurality of built-in drums, the second calibration aid being a calibration drum overlaid on the first calibration aid, and a third 320L calibration drum inside which the first and second calibration aids are inserted; A calibration necessity checking step of checking for non-contamination of the waste, performing decontamination if contaminated, and selecting a reference radioactive waste drum from the actual 200 L radioactive waste drums required for calibration verification inspection;
A hardware checking step of aligning the projection source of each layer and the semiconductor detector;
A software checking step of changing to a nuclide library composed of nuclides of a calibration source and setting software in units of measurement for calculating efficiency of the semiconductor detector, which is a calibrator;
An energy calibration and shape calibration step of the semiconductor detector which performs energy calibration and shape calibration of the semiconductor detector by using a spectrum obtained by shooting a projection source;
In order to calculate the dead time correction coefficient (R _ck ) during the repackaging drum analysis, after inputting a signal having a specific energy into the semiconductor detector at a specific counting rate, the initial counting rate (C ₀ ) of the reference pulse measured at the minimum radiation level is measured. A reference pulse calibration step of measuring;
Calibration value calculation step of calculating the respective calibration values to perform projection source measurement and calibration or multi-efficiency measurement and calibration according to the density of the repacking drum to compensate for radiation attenuation by the medium in the repackaging drum analysis Wow;
A calibration result input step of inputting a calibration value calculated in the software;
A calibration check test step of verifying validity of the calibration by performing an absolute check test or a relative check test when the input calibration value is a plurality of internal drums; And
The calibration method of the nuclide analysis device for improving the nuclide analysis accuracy of the multi-embedded drum, characterized in that the calibration completes the step of switching to the operating state when the calibration is completed. The method of claim 1,
Each medium of the first calibration aid is
Foam, Homosote, Particle Board, Sand, Concrete + Iron Powder,
The density (g / ㏄) of each of the first calibration aids is
A calibration method of a nuclide analysis device for improving nuclide analysis accuracy of a multi-embedded drum, characterized in that 0, 0.02, 0.44, 0.71, 1.66, 3.02. The method of claim 1,
The second calibration aid,
Upper and lower portions are opened so as to cover the first calibration aid, and have a thickness having an effect of compression thickness of 3 to 5 compression drums of a plurality of built-in drums, shielding the source in the first calibration aid, and the third calibration aid. A method of calibrating a nuclide analysis device for improving nuclide analysis accuracy of a plurality of internal drums, characterized in that it has a structure mounted in the center. The method of claim 1,
The energy calibration and shape calibration step of the semiconductor detector,
Adjust the minimum / maximum gamma ray energy corresponding to the minimum / maximum channel of the semiconductor detector to respond, determine the correlation between the reaction channel of the semiconductor detector and gamma ray energy (energy calibration), and measure the half width of the semiconductor detector A method of calibrating a nuclide analysis device for improving nuclide analysis accuracy of a multi-embedded drum, wherein the correlation of gamma ray energy is determined (shape correction), but is performed only once regardless of the measurement geometry and the type of the repackaging drum. The method of claim 1,
The reference pulse calibration step,
Nuclide analysis for improving the accuracy of nuclide analysis of multi-embedded drums, characterized by measuring the initial counting rate (C ₀ ) of the reference pulse at the minimum level of radiation to calculate the dead time correction coefficient (R _ck ) during drum analysis. How to calibrate the device. The method of claim 1,
The calibration value calculation step,
In the case of a single internal drum which is less than the reference density, the first calibration aid, which is an empty container without a calibration source, is mounted at the center of the third calibration aid, and the third calibration aid is divided equally into eight in the height direction. Shooting the projection source every time to determine the initial counting rate (SR _ik ⁰ ) without attenuation of the medium by the spectrum measured by the semiconductor detector, layer 9 is defined as the summated spectrum of the sum of the spectrum obtained from layers 1 to 8 for each channel Using this, calculate the initial count rate (SR _i9 ⁰ ) of layer 9,
If the drum is less than the reference density and multi-loaded drum, the second calibration aid is overlaid on the first calibration aid, which is an empty container with no calibration source, and then mounted at the center of the third calibration aid, and the third calibration aid is mounted. Shoot the projection source for each layer divided equally into eight in the height direction and determine the initial count rate (MR _ik ⁰ ) without media attenuation from the spectrum measured by the semiconductor detector, and layer 9 is the spectrum obtained from layers 1-8. A method of calibrating a nuclide analysis device for improving nuclide analysis accuracy of a plurality of built-in drums, characterized in that is defined as the summation spectrum summed for each channel and calculates the initial count rate (MR _i9 ⁰ ) of the 9th layer. The method of claim 1,
The calibration value calculation step,
In the case of a single-embedded drum having a density higher than the reference density, each of the six first calibration correction elements having a calibration source and a medium inserted therein is mounted at the center of the third calibration aid to repeatedly measure the efficiency of the semiconductor detector for each layer 1-9. To obtain efficiency calibration curves for six densities, and calculate the efficiency of the semiconductor detector by density and gamma ray energy.

) Is calculated for each layer 1-9, and the efficiency reduction ratio (CF (E, ρ)) according to the density increase, which is a calibration value, is calculated using the efficiency of layer 9,
In the case of a multi-embedded drum having a reference density or more, the second calibration aid is overlaid on the first calibration corrector, which is 0 g / ㏄ with no calibration source and medium, and then mounted in the center of the third calibration aid to improve the efficiency of the semiconductor detector. Calculate the efficiency calibration curve by repeating the measurement for each layer 1-9, and applying the efficiency reduction ratio (CF (E, ρ)) according to the density increase of the single internal drum to layer 1-9 for the multi-embedded drum. Efficiency of the semiconductor detector by star, density, and gamma ray energy (

A method of calibrating a nuclide analysis device for improving the accuracy of nuclide analysis of a plurality of built-in drums. The method of claim 1,
The calibration check test step,
In the case of an absolute verification test, the calibration source is performed using the first calibration aid, the second calibration aid, and the third calibration aid,
In the case of a relative verification test, a plurality of characterized in that the reference radioactive waste drum is overlaid on the second calibration aid, mounted in the center of the third calibration aid, and analyzed to have the same result as the measurement result measured in another measurement geometry. Calibration method of nuclide analysis device to improve nuclide analysis accuracy of internal drum.

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