KR102288407B1 - Method for Analyzing Radionuclide and Apparatus for Analyzing Radionuclide - Google Patents

Abstract

The present invention comprises the steps of (A) preparing a sample containing Fe-55 and Ni-59; (B) Converting X-rays generated from Fe-55 and Ni-59 contained in the sample into electric charges, and measuring the intensity of photon energy using silicon as a mediating material when the electric charge moves in a drift electric field obtaining an energy spectrum derived from X-rays of Fe-55 and Ni-59 by detecting with at least one X-ray detector; And (C) determining the radioactivity of Fe-55 and Ni-59 contained in the sample from the X-ray-derived energy spectrum of the obtained Fe-55 and Ni-59; and a first storage container for storing samples containing Fe-55 and Ni-59; It is disposed at a certain distance from the first storage container, converts X-rays generated from Fe-55 and Ni-59 contained in the sample into electric charges, and uses silicon as a medium when the electric charge moves in the drift electric field. at least one X-ray detector that measures the intensity of photon energy to obtain an energy spectrum derived from X-rays of Fe-55 and Ni-59; and a measuring unit for determining the radioactivity of Fe-55 and Ni-59 contained in the sample from the X-ray-derived energy spectrum of the obtained Fe-55 and Ni-59; will be.

Description

A method for analyzing radionuclides and an apparatus for analyzing radionuclides {Method for Analyzing Radionuclide and Apparatus for Analyzing Radionuclide}

The present invention relates to a method for analyzing radionuclides and an apparatus for analyzing radionuclides, and specifically, technology for analyzing Fe-55 and Ni-59, which are radionuclides contained in radioactive solid waste, before storing and disposing of radioactive solid waste. is about

Radioactive waste that is inevitably generated in the process of using nuclear power or dismantling a nuclear power plant must ultimately be permanently isolated from the ecosystem and disposed of. At this time, the disposal method is different depending on the radioactivity (Bq) of the radioactive waste, and the disposal cost varies from several times to several tens of times. In particular, quantitative analysis of Fe-55 and Ni-59 among radionuclides included in radioactive waste is essential.

Conventionally, in order to separate two kinds of nuclides from concrete and soil (radioactive waste) containing Fe-55 and Ni-59, after alkali melting, a liquid scintillation counter (LSC), Analysis was performed using a low energy germanium detector (LEGe) or a silicon lithium semiconductor detector (Si(Li) semiconductor detector).

However, in the chemical separation process, which is the next step after the alkali melting process that can dissolve the concrete or soil material, an additional organic solution is required because the separation is carried out through the addition process of a chemical solution, and a lot of time is required for the separation in that step. There is a problem in that secondary radioactive waste such as organic waste is generated. And for LSC measurement, an organic solvent, LSC-cocktail, is used to mix and measure with the sample to be analyzed. There is a problem in that an organic waste solution containing as many radionuclides as the number of samples to be analyzed for radioactivity that can be representative of radioactive waste is generated, and the waste solution is classified as liquid radioactive waste.

In addition, Fe-55 and Ni-59 are nuclides that emit low-energy X-rays, and Fe-55 and Ni-59 show X-ray emission peaks in energy bands adjacent to each other. , it is impossible to separate the two nuclides because the resolution (resolution) of the peaks in the energy spectrum derived from X-rays emitted from Fe-55 and Ni-59 is low when trying to separate LSC, LEGe, or Si(Li) semiconductor detectors. there is a problem.

In addition, since the LEGe or Si(Li) semiconductor detector must be kept at a low temperature using liquid nitrogen for sufficient conductivity and good resolution, problems occur when used at room temperature, and ancillary equipment such as liquid nitrogen tank is provided And there is a limit to equipment miniaturization due to the need to manage.

Therefore, with the above existing detector, it takes a lot of time and manpower to analyze a large amount of radioactive waste of concrete or soil material generated during the dismantling of nuclear facilities, and there is a problem that it must be used at low temperature (cooling of liquid nitrogen, etc.) In this case, since the detector is frequently replaced, it has several inconveniences such as the need for additional manpower.

The present invention is to solve the above problems, it is possible to use at room temperature without a step of cooling using liquid nitrogen, and to provide a method for analyzing radionuclides without the generation of secondary radioactive waste such as organic waste. .

Furthermore, since the peaks of the two nuclides on the energy spectrum obtained by detecting X-rays generated from Fe-55 and Ni-59 do not overlap each other and are clearly distinguished, the qualitative and quantitative analysis of Fe-55 and Ni-59 contained in radioactive waste. to enable analysis.

According to an embodiment of the present invention, (A) preparing a sample containing Fe-55 and Ni-59; (B) Converting X-rays generated from Fe-55 and Ni-59 contained in the sample into electric charges, and measuring the intensity of photon energy using silicon as a mediating material when the electric charge moves in a drift electric field obtaining an energy spectrum derived from X-rays of Fe-55 and Ni-59 by detecting with at least one X-ray detector; And (C) determining the radioactivity of Fe-55 and Ni-59 contained in the sample from the X-ray-derived energy spectrum of the obtained Fe-55 and Ni-59; provides

In addition, according to another embodiment of the present invention, a first storage container for storing Fe-55 and Ni-59 containing samples; It is disposed at a certain distance from the first storage container, converts X-rays generated from Fe-55 and Ni-59 contained in the sample into electric charges, and uses silicon as a medium when the electric charge moves in the drift electric field. at least one X-ray detector that measures the intensity of photon energy to obtain an energy spectrum derived from X-rays of Fe-55 and Ni-59; and a measuring unit for determining the radioactivity of Fe-55 and Ni-59 contained in the sample from the X-ray-derived energy spectrum of the obtained Fe-55 and Ni-59; do.

According to the method for analyzing radionuclides according to the present invention, an X-ray detector that converts X-rays into electric charges and measures the intensity of photon energy using silicon as a mediating material when the electric charges move in a drift electric field is used. By doing so, quantitative and qualitative analysis of the two nuclides from the energy spectrum derived from X-rays generated from Fe-55 and Ni-59 at room temperature without a cooling process using liquid nitrogen without generating secondary radioactive waste such as organic waste liquid As possible, the problem of organic waste generation in the liquid scintillation counter (LSC) that was conventionally used as an X-ray detector, the low-energy region germanium detector (LEGe), or the detector replacement due to the use of liquid nitrogen in the Si(Li) semiconductor detector It is possible to overcome the troublesome and time-consuming problems of analyzing concrete or soil containing a large amount of radionuclides for the This is possible.

Accordingly, the analysis efficiency can be increased by arranging several miniaturized instruments at the same time, or it can be serially arranged and analyzed continuously (that is, applied to an automated process), so that the efficiency of analyzing one sample is increased, The analysis time of Fe-55 and Ni-59 from nuclide-containing samples can be shortened.

1 is a view showing an energy spectrum derived from X-rays emitted from Fe-55 using the X-ray detector of the present invention.
2 is a diagram showing an energy spectrum derived from X-rays emitted from Ni-59 using the X-ray detector of the present invention.
FIG. 3 is a diagram showing the result of measuring an energy spectrum derived from X-rays emitted from a sample containing Fe-55 and Ni-59 according to an embodiment of the present invention by SDD.
4 is a diagram schematically illustrating a 3D rendering image of a sample and an automated system for an X-ray detector and arrangement of the system according to an embodiment of the present invention.
FIG. 5 is a view showing the result of measuring an energy spectrum derived from X-rays emitted from a sample containing Fe-55 and Ni-59 according to the prior art by an LEGe detector.

Hereinafter, the present invention will be described in detail.

1. Method of analysis of radionuclides

The present invention provides a method for analyzing radionuclides.

The radionuclide analysis method of the present invention comprises the steps of (A) preparing a sample containing Fe-55 and Ni-59; (B) Converting X-rays generated from Fe-55 and Ni-59 contained in the sample into electric charges, and measuring the intensity of photon energy using silicon as a mediating material when the electric charge moves in a drift electric field obtaining an energy spectrum derived from X-rays of Fe-55 and Ni-59 by detecting with at least one X-ray detector; and (C) determining the radioactivity of Fe-55 and Ni-59 contained in the sample from the X-ray-derived energy spectrum of the obtained Fe-55 and Ni-59.

In step (A), the Fe-55 and Ni-59-containing sample may be a precipitate obtained by melting the Fe-55 and Ni-59-containing radioactive solid waste and then precipitating the molten radioactive solid waste. The precipitate (sample) may have a diameter of about 3 to 5 cm and a thickness of 10 to 50 μm.

In addition, the precipitate is placed in direct contact with the X-ray detector after the sealing step (to prevent contamination of the X-ray detector) for higher analysis efficiency and reduction of analysis time to analyze radionuclides. there is.

In particular, as described above, the radionuclide analysis method of the present invention does not use a liquid scintillation counter (LSC) and introduces a precipitation-type sample pretreatment method, so that organic waste is not generated at all.

That is, the method for analyzing the radionuclide may be one that does not substantially generate secondary radioactive waste including organic waste liquid, and the meaning that secondary radioactive waste containing the organic waste liquid does not substantially generate is, It may be that the secondary radioactive waste is not generated at all or is generated in a small amount so as not to affect the detection of the X-ray-derived energy spectrum of the Fe-55 and the Ni-59.

In step (B), the X-ray detector converts X-rays generated from Fe-55 and Ni-59 contained in the sample into electric charges, and when the electric charges move in a drift electric field, silicon is used as a mediating material. By measuring the intensity of the photon energy using the X-ray-derived energy spectrum of the Fe-55 and the Ni-59 can be obtained.

The X-ray detector may include a silicon-based semiconductor detector. In the semiconductor detector, when electric charges (or ionized particles) generated by X-rays are incident on the semiconductor detector, electron-hole pairs are generated, and these electrons and holes move to the electrode along the electric field to create an electrical signal (photon energy). . In the above semiconductor detector, since the energy required to generate an electron-hole pair is 10 times less than the energy required to generate an electron-ion pair, more charged particles are generated than the gas detector for the same amount of particle energy, and as a result, more charged particles are generated than the gas detector. Energy resolution can be improved.

The X-ray detector may use high-purity silicon as an intermediate material. In addition, the X-ray detector may include a series of electrodes that use a flat cathode and have a concentric circle with an anode forming a small circle in the center. Accordingly, charges (or ions) generated by X-rays generated from Fe-55 and Ni-59 form concentric circles. The concentric series of electrodes forms a drift electric field that moves charges, and the charges are collected at the central anode, and the anode with a small area maintains a very small capacitance to reduce electronic noise, resulting in improved resolution (About 123 to 135 eV FWHM at 4 μs peaking time @ 5.9 keV).

The Si(Li) or Ge(Li) semiconductor detector forms a pn junction by diffusing Li in p-type Si or p-type Ge in order to increase the thickness of the depletion layer, and then applies a reverse voltage to flow lithium (Li) ions. It is formed by adding an intrinsic semiconductor part called the i-layer (intrinsic region) between the p-type and the n-type by drifting. In order to maintain the lithium flow correction region or to prevent the diffusion of drifted lithium ions at room temperature, it must always be stored and used by cooling it to liquid nitrogen temperature.

However, since the X-ray detector used in the present invention uses silicon, not lithium, as a medium, it does not need to include a cooling process such as liquid nitrogen temperature. That is, the analysis method of the radionuclide may not substantially include the step of cooling using liquid nitrogen, and the meaning that it does not substantially include the step of cooling using liquid nitrogen means that in the analysis method of the radionuclide, the liquid It may mean that the step of cooling with nitrogen does not have to be performed at all.

The radionuclide analysis method may be performed at 5 to 30 °C, specifically 10 to 30 °C, more specifically 15 to 25 °C. That is, the method of analyzing the radionuclide may be performed at room temperature.

Specifically, the X-ray detector may include a Silicon Drift Detector (SDD) among silicon-based semiconductor detectors.

On the other hand, looking at the X-ray-derived energy spectrum obtained by independently detecting Fe-55 and Ni-59 with the X-ray detector, as shown in FIG. 1 , Fe-55 is 5.6 to 6.0 keV and 6.2 to 6.6 keV. An energy spectrum derived from X-rays can be obtained in the energy band, and as shown in FIG. 2 , for Ni-59, an energy spectrum derived from X-rays can be obtained in energy bands of 6.7 to 7.0 keV and 7.4 to 7.8 keV.

Specifically, Fe-55 shows X-ray emission peaks in the energy bands of 5.9 keV and 6.5 keV, and Ni-59 shows X-ray emission peaks in the energy bands of 6.9 keV and 7.7 keV.

It is not easy to separate the two radionuclides (Fe-55, Ni-59) showing the peaks of the adjacent energy bands through conventional radiation detectors (eg, LSC, LEGe, Si(Li) semiconductor detector). , X-ray-derived energy spectrum is measured by detecting X-rays emitted from Fe-55 and Ni-59 of the Fe-55 and Ni-59-containing sample with the X-ray detector according to the radionuclide analysis method of the present invention. Then, as shown in FIG. 3 , it can be confirmed that a total of four peaks can be accurately distinguished.

In addition, in step (C), the step of determining the radioactivity of Fe-55 and Ni-59 contained in the sample from the X-ray-derived energy spectrum of Fe-55 and Ni-59 obtained in step (B), After determining the measurement efficiency of the X-ray detector through detector calibration using a standard radionuclide with known radioactivity, the count rate of a specific peak region in the energy spectrum obtained when measuring with the X-ray detector for an unknown sample (per second measured value), the measured efficiency and the decay probability of the radionuclide (Fe-55 or Ni-59) to be measured It can be performed through a method of calculating the total amount of radioactivity (Bq) emitted from Fe-55 or Ni-59 contained in the sample by dividing it by the value multiplied by the radioactive decay probability).

The standard radionuclide is a nuclide with known radioactivity contained in the nuclide, and is not limited thereto as long as it is a radionuclide guaranteed by a manufacturing organization (NPL, Ekert & Zigler, etc.) for a standard source of radioactivity. For example, 1 mL of Ni-59 Certified Reference Material (CRM) with a concentration of 100 Bq/g is diluted with 9 mL of distilled water that does not contain radioisotopes, and finally 1,000 Bq of Ni-59 is diluted with 9 mL of distilled water. can be used as a sample.

The measurement efficiency is an index used when determining the detector characteristics of the X-ray detector (SDD) through a standard radionuclide of known radioactivity, and when measuring X-rays generated from the standard radionuclide with the X-ray detector , the value obtained by measuring the number of X-ray photons (counts per sec. (cps)) entering the counter during unit time is the product of the radioactivity of the standard radionuclide and the radionuclide energy decay probability of the standard radionuclide It means the percentage (%) of the value divided by .

In addition, the radionuclide analysis method of the present invention comprises the steps of (A1) preparing a sample containing Fe-55 and Ni-59 accommodated in a first storage container; (B1) At least one X that converts X-rays generated from Fe-55 and Ni-59 contained in the sample into electric charges, and measures photon energy using silicon as a mediating material when the electric charge moves in a drift electric field obtaining an energy spectrum derived from X-rays of the Fe-55 and the Ni-59 by detecting with a ray detector; And (C1) after determining the radioactivity of Fe-55 and Ni-59 contained in the sample from the X-ray-derived energy spectrum of the obtained Fe-55 and Ni-59, the first storage container is transferred to the outside, A cycle including replacing the Fe-55 and Ni-59-containing sample with the second storage container may be repeatedly performed at regular time intervals.

According to the method for analyzing radionuclides of the present invention, there is no need to provide liquid nitrogen-related equipment because cooling to liquid nitrogen temperature is not required, and since organic waste liquid is not generated during the analysis process, related equipment that needs to treat organic waste liquid is also There is no need to provide, and as the equipment can be miniaturized, it is possible to repeatedly perform radionuclide analysis by applying it to a series of automated processes as described above, thereby reducing the analysis time of radionuclides and increasing the analysis efficiency. .

Specifically, in step (C1), the first storage container may be replaced with the second storage container arranged in series with the first storage container. The first storage container and the second storage container may accommodate the same or different Fe-55 and Ni-59-containing samples.

As shown in FIG. 4 , a transfer means may be used to replace the first storage container with the second storage container, and the transfer means transfers the first storage container to the outside at regular time intervals, and the second storage container The 1 storage container can be replaced with the 2nd storage container. The transport means may be used without limitation as long as it can transport the first storage container, and specifically, it may be a retractor, a vehicle, a movable belt, an automatic traction robot, and the like, but is not limited thereto. Preferably the conveying means may comprise a moving belt. The movable belt may specifically be a conveyor belt, a plate belt, etc., but is not limited thereto.

That is, the first storage container and the second storage container may be arranged in a series on the transfer means.

The first storage container may use a vial made of polyolefin or a filter. The polyolefin may include at least one selected from polyethylene, polypropylene, polyisopropylene, polybutyrene, and mixtures thereof, but is not limited thereto. The filter may include a glass microfiber filter. The glass fiber filter may include a filter having a pore size of 1 to 1.5 μm, preferably 1.2 μm, for example, a Whatman GF/C (pore size: 1.2 μm) filter.

When a filter other than a vial is used as the first storage container, a polypropylene film may be used to protect the surface of an unknown sample accommodated in the filter and to prevent contamination of the X-ray detector.

The X-ray detector may have a distance of 20 mm or less from the first storage container. In addition, the Fe-55 and Ni-59-containing sample (precipitate) is placed in direct contact with the X-ray detector after the sealing step as described above (to prevent contamination of the X-ray detector) to release radionuclides can also be analyzed.

In addition, the at least one X-ray detector may be a plurality of X-ray detectors spaced apart at regular intervals. For example, one X-ray detector (SDD) may be disposed above and/or below one sample, respectively, but a plurality of X-ray detectors (SDD) are disposed above and/or below one sample (sample). SDD) may be disposed, and if a plurality of X-ray detectors are disposed at the same position from the sample (first storage container), the present invention is not limited thereto.

2. Radionuclide analysis device

The present invention provides an apparatus for analyzing radionuclides.

The radionuclide analysis device includes: a first storage container for storing Fe-55 and Ni-59-containing samples; It is disposed at a certain distance from the first storage container, converts X-rays generated from Fe-55 and Ni-59 contained in the sample into electric charges, and uses silicon as a medium when the electric charge moves in the drift electric field. at least one X-ray detector that measures the intensity of photon energy to obtain an energy spectrum derived from X-rays of Fe-55 and Ni-59; and a measuring unit for determining the radioactivity of Fe-55 and Ni-59 contained in the sample from the obtained X-ray-derived energy spectrum of Fe-55 and Ni-59.

In particular, the radionuclide analysis apparatus of the present invention does not need equipment related to liquid nitrogen cooling or equipment related to organic waste liquid treatment, so that the equipment can be miniaturized, so it can be applied to a series of automated processes to repeatedly perform radionuclide analysis there is.

Therefore, the apparatus for analyzing the radionuclide transfers the first storage container in which the Fe-55 and Ni-59-containing samples are accommodated to the outside at regular time intervals as shown in FIG. It may further include a transfer means for replacing the -55 and Ni-59-containing samples with the second storage container.

As described above, since the X-ray detector uses silicon rather than lithium as a medium, it may not include a cooling process such as liquid nitrogen temperature. And, specifically, it may be carried out at 10 to 30 ℃, more specifically 15 to 25 ℃. To this end, the apparatus for analyzing the radionuclide may further include a temperature control means.

The measuring unit may determine the radioactivity of Fe-55 and Ni-59 contained in the sample from the X-ray-derived energy spectrum of the Fe-55 and Ni-59. The method of determining the radioactivity of Fe-55 and Ni-59 contained in the sample is, '1. The same method as described above in 'Analysis method for radionuclides' can be applied.

In addition, the X-ray detector may include a silicon-based semiconductor detector as described above, and the X-ray detector may use high-purity silicon as an intermediate material.

The X-ray detector may not include a cooling process such as liquid nitrogen temperature because it uses silicon, not lithium, as a mediating material among silicon-based semiconductor detectors. It may not include substantially. The meaning that the cooling member is not substantially included may mean that the apparatus for analyzing the radionuclide does not need to include the cooling member at all.

Specifically, the X-ray detector may include a Silicon Drift Detector (SDD), the distance from the first storage container to the X-ray detector may be 20 mm or less, and the at least one X-ray detector is spaced apart at regular intervals. It may be a plurality of X-ray detectors.

In addition, the Fe-55 and Ni-59 containing samples, the first storage container, the X-ray detector is '1. The same method as described above in 'Analysis method for radionuclides' can be applied.

As described above, in the case of using the radionuclide analysis device according to the present invention, secondary radioactive waste including organic waste is not generated and a cooling member using liquid nitrogen is not required, so a miniaturized system can be configured. In addition, as quantitative and qualitative analysis is possible from the energy spectrum derived from X-rays generated from Fe-55 and Ni-59 at room temperature, organic waste is generated in the liquid scintillation counter (LSC), which was conventionally used as an X-ray detector. A lot of time and manpower is required to solve the problem, to replace the detector due to the use of liquid nitrogen in the low-energy region germanium detector (LEGe) or Si(Li) semiconductor detector, and to analyze concrete or soil containing a large amount of radionuclides. problems can be overcome.

Furthermore, it is possible to increase the analysis efficiency by arranging several miniaturized devices (X-ray detectors) at the same time, or to analyze them continuously (that is, applied to an automated process) by placing them in series, so that the efficiency of analyzing one sample is increased. As a result, the analysis time of Fe-55 and Ni-59 from samples containing radionuclides can be shortened.

Hereinafter, before performing qualitative/quantitative analysis of Fe-55 and Ni-59 of unknown radioactive solid waste, a specific method of calculating the measurement efficiency of an X-ray detector using a standard radionuclide of known radioactivity (Bq) is described. described.

For example, after alkali-melting a mixture of standard radionuclides with Fe-55 and Ni-59 (standard radionuclides with known radioactivity (Bq)) in a 15 mL tube for centrifugation, add a carrier in 5 mL of 0.2% nitric acid solution. It can be prepared by adding 2 mg each of iron and nickel, and then adding Fe-55 and Ni-63, respectively. The mixed solution is mixed with the lid closed and shaken well, and then the pH is raised to between 8 and 9 by adding 4 M sodium hydroxide solution. After leaving the precipitate at room temperature for about 30 minutes so that the precipitate is matured well, the precipitate with a diameter of 2 cm and a maximum thickness of 50 μm can be separated using a Whatman GF/C (pore size: 1.2 μm) filter. After the separation of the filter is dried, the sample can be prepared by wrapping it with a polypropylene film (thickness: 0.2 μm) to protect the surface and prevent contamination of the detector.

The energy spectrum derived from X-rays measured using the X-ray detector SDD (XR-100 Fast SDD-70) of the present invention for the sample is shown in FIG. 3 .

By measuring the number (count) of X-ray photons of Fe-55 and Ni-59 entering the counter of the SDD at room temperature using the sample prepared above, the counting rate (counting per unit time) is measured, and the standard radionuclide By dividing by the product of the radionuclide energy decay probability in each energy region of Fe-55 and Ni-59 by the radioactivity (Bq) of (see Equation 1 below), The measurement efficiency of SDD can be calculated.

<Formula 1>

(where A: radioactivity (Bq), CPS: counting rate, ε: SDD detector measurement efficiency, γ: radionuclide energy decay probability)

The radionuclide energy decay probabilities in each energy region of Fe-55 and Ni-59 can be obtained from Monographie BIPM-Table of Radionuclides Vol.3, page 5 and Vol.6, page 7 as theoretical values.

The measurement efficiency of the SDD calculated above may have errors depending on the radioactivity of the standard radionuclide, the probability of radionuclide energy decay, the number of measurements, etc., and in order to reduce these errors, the measurement efficiency (correction value) obtained through the calibration process may be used. .

Using the measurement efficiency (correction value), qualitative and quantitative analysis of unknown radioactive solid waste can be performed using the SDD.

Specifically, when an energy spectrum derived from X-rays is measured for the radioactive solid waste using the SDD, which is an X-ray detector of the present invention, if an energy spectrum as shown in FIG. 3 is obtained, the unknown radioactive solid waste contains Fe- It can be seen that 55 and Ni-59 are contained.

Next, the number of X-ray photons (count) of Fe-55 and Ni-59 entering the counter of the SDD at room temperature for the radioactive solid waste is measured for a certain period of time to determine the counting rate (count per unit time) Calculated and divided by the product of the pre-calculated measurement efficiency of SDD and the probability of decay of radionuclide energy in each energy region of Fe-55 and Ni-59, Fe contained in radioactive solid waste through Equation 1 above The radioactivity (Bq) derived from each of the energy regions of -55 and Ni-59 can be measured.

In particular, in the case of using the X-ray detector (SDD) of the present invention, it can be confirmed that the peaks in each energy region do not overlap, but are clearly separated and appear as four for radioactive solid waste containing Fe-55 and Ni-59. In the case of measurement using an existing LEGe detector (ORTEC, GLP-36360/13), it can be confirmed that the energy spectrum peaks derived from X-rays overlap each other as shown in FIG. It can be seen that the process of separating Fe-55 and Ni-59 nuclides must be performed before analysis.

That is, according to the radionuclide analysis method and apparatus of the present invention, the peaks for each energy region of the two nuclides in the energy spectrum derived from X-rays can be visually observed without prior separation of Fe-55 and Ni-59 contained in radioactive solid waste. are also clearly separated, so that qualitative and quantitative analysis were possible only with a single measurement. It was confirmed that this is because the X-ray detector according to the present invention has superior resolution (resolution) of the energy spectrum peaks derived from X-rays of Fe-55 and Ni-59 compared to the conventional detector.

Claims (16)

(A) preparing a sample containing Fe-55 and Ni-59 in a first storage container;
(B) Converting X-rays generated from Fe-55 and Ni-59 contained in the sample into electric charges, and measuring the intensity of photon energy using silicon as a mediating material when the electric charge moves in a drift electric field obtaining an energy spectrum derived from X-rays of Fe-55 and Ni-59 by detecting with a plurality of X-ray detectors spaced apart at regular intervals; and
(C) After determining the radioactivity of Fe-55 and Ni-59 contained in the sample from the X-ray-derived energy spectrum of the obtained Fe-55 and Ni-59, the first storage container is transferred to the outside, and the Replacing the first storage container with a second storage container in which Fe-55 and Ni-59 containing samples are accommodated and arranged in series with the first storage container; a cycle comprising a cycle at regular time intervals performed repeatedly,
The Fe-55 and Ni-59-containing sample is a radionuclide analysis method in which the precipitate obtained by melting the Fe-55 and Ni-59-containing radioactive solid waste and then precipitating the molten radioactive solid waste is sealed. . delete The method according to claim 1,
The X-ray detector is an analysis method of radionuclides comprising SDD (Silicon Drift Detector). The method according to claim 1,
The analysis method of the radionuclide substantially does not include the step of cooling using liquid nitrogen. The method according to claim 1,
The analysis method of the radionuclide is an analysis method of a radionuclide that does not substantially generate secondary radioactive waste including organic waste. delete delete delete The method according to claim 1,
The method of analyzing radionuclides that the distance from the first storage container to the at least one X-ray detector is 20 mm or less. a first storage container for storing samples containing Fe-55 and Ni-59;
It is disposed at a certain distance from the first storage container, converts X-rays generated from Fe-55 and Ni-59 contained in the sample into electric charges, and uses silicon as a medium when the electric charge moves in the drift electric field. A plurality of X-ray detectors spaced apart at regular intervals to obtain an energy spectrum derived from X-rays of the Fe-55 and the Ni-59 by measuring the intensity of photon energy;
By transferring the first storage container in which the Fe-55 and Ni-59-containing samples are accommodated to the outside at regular time intervals, the Fe-55 and Ni-59-containing samples are accommodated in the first storage container, and the first storage container and a transport means for replacing it with a second storage container arranged in series; and
a measuring unit for determining radioactivity of Fe-55 and Ni-59 contained in the sample from the obtained X-ray-derived energy spectrum of Fe-55 and Ni-59;
including,
The Fe-55 and Ni-59-containing sample is a radionuclide analysis device in which the precipitate obtained by melting the Fe-55 and Ni-59-containing radioactive solid waste and then precipitating the molten radioactive solid waste is sealed. . delete delete 11. The method of claim 10,
The X-ray detector is a radionuclide analysis device comprising a SDD (Silicon Drift Detector). 11. The method of claim 10,
The radionuclide analysis device substantially does not include a cooling member using liquid nitrogen. 11. The method of claim 10,
The apparatus for analyzing radionuclides, wherein the distance from the first storage container to the at least one X-ray detector is 20 mm or less. delete

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