JP2017015543A - Tritium concentration measurement device and tritium separation system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tritium concentration measurement device that continuously measures the concentration of tritium in a tritium-containing water.SOLUTION: The tritium concentration measurement device causes tritium to be adsorbed by immersing a main body having a tritium adsorbent containing manganese oxide with a spinel crystal structure containing hydrogen or lithium, into a tritium-containing water, and measures the concentration of tritium based on the physical quantity showing an index of an electron beam from the absorbed tritium.SELECTED DRAWING: Figure 1

Description

  The present disclosure relates to a tritium concentration measuring device that measures the tritium concentration of tritium-containing water, and a tritium separation system including the tritium concentration measuring device.

In a nuclear facility that uses a fission reaction, wastewater containing radioactive materials generated by the fission reaction is generated. Such wastewater contains various radioactive substances. Most radioactive materials such as cesium and strontium can be relatively removed by existing purification facilities due to technological advances, but there are also materials that are difficult to separate such as tritium (T). In particular, tritium is a radioisotope of hydrogen (H), and is typically present in normal water (H ₂ O) as isotope water (T ₂ O, THO) or tritium ion ( ³ T ⁺ ). Therefore, it is difficult to separate from other isotopes.

  As a tritium separation technology, a distillation process that uses a slight difference in boiling point from other isotopes is known, but it requires a large amount of equipment and is expensive and unsuitable for treating large volumes of wastewater. . Further, as a treatment method other than the separation of tritium-containing water, there is a method of attenuating radioactivity by storing wastewater for a long time, but the half-life of tritium is as long as about 12 years. Therefore, in order to treat a large amount of wastewater, a large-scale storage facility is required, which is not suitable.

  As one clue for solving such a problem, Patent Document 1 discloses hydrogen or lithium-containing manganese oxide having a spinel crystal structure as a novel material capable of separating tritium by adsorption. In such an adsorption reaction using a new material, it is expected that the energy consumption is less than that of a conventional distillation process, and tritium can be separated with simple equipment.

International Publication WO2015 / 037734A1

  According to Patent Document 1, the tritium adsorption effect by hydrogen or lithium-containing manganese oxide having a spinel crystal structure is obtained for a while after the substance comes into contact with tritium-containing water, while the predetermined time is It shows the property that once adsorbed tritium is released. Therefore, when separating tritium from tritium-containing water, if the tritium adsorbent is not released from the tritium-containing water at an appropriate timing, the tritium adsorbed on the tritium adsorbent will be released again into the tritium-containing water. There is a problem in that the separation performance of the is reduced.

  In order to solve such problems, the tritium concentration of the tritium-containing water to be treated is continuously monitored, and the adsorption treatment is terminated at a timing when the tritium concentration is sufficiently reduced, so that the subsequent tritium release It is necessary to avoid the concentration deterioration due to. Here, some of the methods for measuring the tritium concentration are conventionally known, but as described below, this is not suitable for the above application. As a conventional method for measuring tritium concentration, for example, tritium-containing water to be measured is collected, added with a standard luminescent material, placed in a standard cell, and the amount of luminescence for a certain time using a liquid scintillation counter. There is a method to detect with. Because this approach is implemented in a batch mode, it is not suitable for applications that continuously monitor the tritium concentration of a particular target. Since tritium-containing water discharged from nuclear facilities has a low dose rate of, for example, about 1 MBq / L, the tritium concentration is monitored because the conventional method requires a minute unit to measure the tritium concentration quantitatively. As a use, the time lag is large and it is not suitable.

  At least one embodiment of the present invention has been made in view of the above-described problems, and a tritium concentration measuring device capable of continuously measuring the tritium concentration of tritium-containing water, and a tritium separation system including the tritium concentration measuring device. The purpose is to provide.

(1) A tritium concentration measuring apparatus according to at least one embodiment of the present invention is a tritium concentration measuring apparatus for measuring the tritium concentration of tritium-containing water in order to solve the above-described problem, and has a main body and a spinel crystal structure. A tritium adsorbent containing hydrogen or lithium-containing manganese oxide and arranged on the main body so as to be in contact with the tritium-containing water, and a physical quantity indicating an index of an electron beam from tritium adsorbed on the tritium adsorbent is measured. Measuring means, and calculating means for calculating the tritium concentration based on the physical quantity.

  According to the configuration of (1) above, when the main body provided with the tritium adsorbent is immersed in the tritium-containing water to be measured, the tritium adsorbent comes into contact with the tritium-containing water, and the spinel contained in the tritium adsorbent. Tritium is adsorbed to hydrogen or lithium-containing manganese oxide having a crystal structure. The measuring means measures a physical quantity indicating an index of an electron beam from tritium adsorbed on the tritium adsorbent, and the tritium concentration is calculated by the calculating means. Here, since the tritium adsorbed on the tritium adsorbent is greatly concentrated compared to the tritium-containing water, the measurement means can measure the electron beam from the tritium adsorbed on the tritium adsorbent, so that good measurement is possible. Accuracy is obtained. Thus, in this configuration, the tritium concentration can be calculated by measuring the electron beam from the tritium adsorbed on the tritium adsorbent from the tritium-containing water that is the measurement target, instead of the batch type. This is also applicable to continuous monitoring of tritium concentration.

(2) In some embodiments, in the configuration of (1), the main body is a conductor that is grounded via a ground wire, and the measurement unit calculates a current value flowing through the ground wire as the physical quantity. Detect.

  According to the configuration of (2) above, an electron flow is induced in the ground wire by the electron beam emitted from the tritium adsorbed on the tritium adsorbent, and a current flows. Since the magnitude of this current corresponds to the amount of tritium adsorbed, the tritium concentration can be suitably measured by detecting the current value.

(3) In some embodiments, in the configuration of the above (2), the plurality of conductors are connected in parallel to the ground line, and the measuring unit is configured as the physical quantity from the plurality of conductors. The total value of the current flowing through the ground line is measured.

  According to the configuration of (3) above, even if the electron beam from the tritium adsorbed on the tritium adsorbent is weak due to, for example, the tritium concentration of the tritium-containing water being low, an equivalent configuration is used as the ground wire. On the other hand, by providing a plurality in parallel, the concentration can be measured by measuring the total current value from each as a physical quantity. That is, a highly accurate tritium concentration is possible.

(4) In some embodiments, in the configuration of (1), the phosphor further includes a phosphor disposed in contact with the tritium adsorbent and issuable by the electron beam, and the measurement unit includes the physical quantity as the physical quantity. , Light emitted from the phosphor is measured.

  According to the configuration of (4) above, the electron beam emitted from the tritium adsorbed on the tritium adsorbent causes the phosphor that contacts the tritium adsorbent to emit light. Since the light intensity emitted from the phosphor depends on the adsorption amount of the tritium adsorbent, the measurement means can measure the tritium concentration by detecting the light emission amount as a physical quantity.

(5) In some embodiments, in the configuration of (4), the main body includes a permeable material, an outer surface is covered with the tritium adsorbent, and an inner surface is covered with a reflective film. The measuring means measures light output through the inside of the cylindrical shape as the physical quantity.

  According to the configuration of (5) above, the phosphor emits light by the electron beam emitted from the tritium adsorbed on the tritium adsorbent covering the outer surface of the main body. The light emitted from the phosphor passes through the main body including the transparent material and is output through the inside of the cylindrical shape. Since the cylindrical inner surface is covered with a reflective film, the light from the phosphor is condensed over a wide range, and good measurement accuracy can be obtained.

(6) In some embodiments, in the configuration of (1), the main body is made of a transmissive material including a phosphor that can emit light by the electron beam, and the main body and the tritium adsorbent are interposed between the main body and the tritium adsorbent. And a conductor film connected to a ground line, wherein the measuring unit measures a current flowing through the ground line as the physical quantity and light emitted from the phosphor.

  According to the configuration of (6) above, a part of the electron beam emitted from the tritium adsorbed on the tritium adsorbent induces a current in the conductor film provided between the main body and the tritium adsorbent. Then, the remainder passes through the thin conductive film, and the phosphor contained in the main body emits light. The measurement unit can measure the tritium concentration with high accuracy by measuring both the current and the light thus generated.

(7) A tritium separation system according to at least one embodiment of the present invention is a tritium separation system that separates the tritium from the tritium-containing water in order to solve the above-described problem, and the tritium-containing water is converted into a spinel crystal structure. The tritium adsorption treatment is carried out by bringing the tritium adsorbent into contact with a tritium adsorbent containing hydrogen or lithium-containing manganese oxide, and the tritium concentration measuring device according to any one of (1) to (6) above Monitoring is performed by measuring the tritium concentration of the tritium-containing water.

  According to the configuration of (7) above, when the tritium-containing water is separated using the tritium adsorbent containing hydrogen or lithium-containing manganese oxide having a spinel crystal structure, The tritium concentration can be monitored continuously. Thus, the adsorption process can be completed at an appropriate timing while monitoring the progress of tritium adsorption.

(8) In some embodiments, in the configuration of (7), the adsorption process is terminated at a timing when the tritium concentration measured by the tritium concentration measuring device is equal to or lower than a preset target value.

  According to the configuration of (8) above, the adsorption process can be completed at the timing when the target adsorption effect is obtained while continuously monitoring the tritium concentration. Thereby, it is possible to effectively avoid a decrease in the tritium separation performance due to the release of tritium adsorbed on the tritium adsorbent again after a predetermined period has elapsed since the start of adsorption.

  According to at least one embodiment of the present invention, a tritium concentration measuring device capable of continuously measuring the tritium concentration of tritium-containing water and a tritium separation system including the tritium concentration measuring device can be provided.

It is a mimetic diagram showing the whole tritium concentration measuring device composition concerning some embodiments of the present invention. It is the sectional view on the AA line of FIG. It is a schematic diagram which shows the modification of FIG. It is a mimetic diagram showing the whole tritium concentration measuring device composition concerning some embodiments of the present invention. It is a schematic diagram which shows the cross-sectional structure of the main body vicinity of FIG. It is a schematic diagram which shows the modification of FIG. It is a mimetic diagram showing the whole tritium concentration measuring device composition concerning some embodiments of the present invention. It is a schematic diagram which shows the whole structure of the tritium separation system which concerns on some embodiment of this invention. It is a flowchart which shows the tritium separation method implemented by the tritium separation system of FIG. 8 for every process. It is a graph which shows an example of transition of the tritium density | concentration with respect to the reaction time by a tritium adsorption material.

Hereinafter, some embodiments of the present invention will be described with reference to the accompanying drawings. However, the dimensions, materials, shapes, relative arrangements, etc. of the components described in the embodiments or shown in the drawings are not intended to limit the scope of the present invention, but are merely illustrative examples. Absent.
For example, expressions expressing relative or absolute arrangements such as “in a certain direction”, “along a certain direction”, “parallel”, “orthogonal”, “center”, “concentric” or “coaxial” are strictly In addition to such an arrangement, it is also possible to represent a state of relative displacement with an angle or a distance such that tolerance or the same function can be obtained.
In addition, for example, expressions representing shapes such as quadrangular shapes and cylindrical shapes not only represent shapes such as quadrangular shapes and cylindrical shapes in a strict geometric sense, but also within the range where the same effect can be obtained. A shape including a chamfered portion or the like is also expressed.
On the other hand, the expressions “comprising”, “comprising”, “comprising”, “including”, or “having” one constituent element are not exclusive expressions for excluding the existence of the other constituent elements.

  FIG. 1 is a schematic diagram showing an overall configuration of a tritium concentration measuring apparatus 1A according to some embodiments of the present invention, and FIG. 2 is a cross-sectional view taken along line AA of FIG.

  The tritium concentration measuring device 1A is a device for measuring the concentration of tritium contained in, for example, tritium-containing water 2 that is waste water of nuclear facilities, and the main body 6 provided with the tritium adsorbent 4 on the surface is connected to the tritium-containing water 2. It is used by soaking in. Particularly in the present embodiment, the main body 6 is an electrode configured to include a conductor such as metal, and the tritium adsorbent 4 is attached to the surface thereof.

  The tritium adsorbent 4 contains hydrogen having a spinel crystal structure or lithium-containing manganese oxide. Hydrogen or lithium-containing manganese oxide having a spinel crystal structure has an adsorption effect of taking in tritium when in contact with tritium-containing water. According to Patent Document 1, the adsorbing reaction of the material is such that hydrogen ions or lithium ions contained in the spinel crystal structure of manganese oxide are ion-exchanged with tritium ions in water. It moves into the spinel crystal structure and is further trapped in the solid phase by weak covalent bonds (strong hydrogen bonds) with oxygen atoms in the crystal, resulting in a decrease in tritium concentration in the water. In FIG. 2, a state in which tritium in the tritium-containing water 2 is attached to the tritium adsorbent 4 is schematically shown.

  Tritium adsorbed on the tritium adsorbent 4 is a radioactive substance and emits an electron beam mainly composed of β rays. Since β rays are weak in intensity and have a short reach distance, it takes time to detect even with a liquid scintillation counter, but can be suitably detected with this configuration as described below.

  First, tritium adsorbed on the tritium adsorbent 4 is captured in a form that is greatly concentrated as compared to the tritium concentration of the tritium-containing water 2 (typically concentrated about 1000 times). In general, β-rays emitted from tritium are weak and difficult to detect, but detection is facilitated by measuring β-rays from tritium present in a concentrated manner. Although the β-ray has a short reach, the tritium adsorbent 4 on which tritium is adsorbed is provided on the main body 2 that is a conductor, and therefore, an electron flow is induced in the main body 6 by the β-ray.

  Since the ground wire 8 is connected to the main body 6, the flow of electrons induced in the main body 6 becomes a current I based on a potential difference from the ground. The current I is detected by a current detection sensor 10 provided on the ground line 8. The detection value of the current detection sensor 10 is sent to the calculation means 12 which is an electronic calculator such as a computer, for example, and is calculated as the tritium concentration.

  Here, since the magnitude of the current I generated in the grounding wire 8 corresponds to the amount of adsorption of the tritium adsorbent 4, the calculation means 12 calculates the tritium concentration based on the detection value of the current detection sensor 10. The relationship between the current I and the tritium concentration may be grasped in advance by an experimental, theoretical, or simulation method and configured to be able to be calculated based on a predetermined arithmetic expression.

  As described above, according to the present embodiment, the tritium concentration is determined by measuring the electron beam from the tritium adsorbed on the tritium adsorbent 4 from the tritium-containing water 2 to be measured as a current instead of the batch type. It can be calculated. Moreover, since the conventional liquid scintillation counter processes with several mL scale liquid, it is difficult to measure an object with a large capacity, and it is also difficult to measure the concentration in real time for batch processing. On the other hand, in the present embodiment, the measurement is performed by immersing in the tank in which the processing target is stored, and thus measurement is possible regardless of the capacity of the processing target. Moreover, since it can measure by the electric current detection based on the electron beam discharge | released from the adsorbed tritium irrespective of a batch process, continuous monitoring is possible and real-time measurement is also attained by increasing a processing speed.

  Next, a modification of the above embodiment will be described with reference to FIG. FIG. 3 is a schematic diagram showing a modified example 1B of the tritium concentration measuring apparatus of FIG.

  In the modified example 1B, a plurality of main bodies 6 having tritium adsorbents 4 provided on the surface thereof are provided, and these are connected in parallel to the ground wire 8. A combined current I of current values ia, ib, ic, and id flowing through the main body 6 by the electron beam emitted from the tritium adsorbed on each tritium adsorbent 4 flows through the ground line 8.

  The current detection sensor 10 detects the combined current I (= ia + ib + ic + id), and the tritium concentration is calculated by the calculation means 12. Thus, in this embodiment, the tritium concentration is calculated based on the combined current I of a plurality of currents. Therefore, for example, even when the electron beam from the tritium adsorbed on the tritium adsorbent 4 is weak because the tritium concentration of the tritium-containing water 2 is low, a plurality of equivalent configurations are arranged in parallel with the ground line 8. By providing, it is possible to measure the concentration by measuring the total of the current values from each as a physical quantity. As a result, a highly accurate tritium concentration is possible.

  FIG. 4 is a schematic diagram showing an overall configuration of a tritium concentration measuring apparatus 1C according to some embodiments of the present invention, and FIG. 5 is a schematic diagram showing a cross-sectional structure in the vicinity of the main body 6 of FIG.

  The tritium concentration measuring device 1 </ b> C is a device for measuring the tritium concentration of the tritium-containing water 2 as in the above-described embodiment, and the main body 6 provided with the tritium adsorbent 4 on the surface is immersed in the tritium-containing water 2. Have been used. The main body 6 is provided with the tritium adsorbing material 4 so as to cover the surface. In this embodiment, the main body 6 includes a phosphor 14 that can emit light by an electron beam emitted from the tritium adsorbed on the tritium adsorbing material 4. There are features.

  As shown in FIG. 5, the phosphor 14 is provided between the main body 6 and the tritium adsorbent 4. Therefore, the electron beam emitted from the tritium adsorbed on the tritium adsorbent 4 is configured to easily reach the phosphor 14 in contact therewith. As a result, the phosphor 14 emits light by the electron beam emitted from the tritium adsorbed on the tritium adsorbent 4.

  The main body 6 includes a permeable material and is formed in a cylindrical shape. Particularly in the present embodiment, the main body 6 is made of a glass material, and light emitted from the phosphor 14 can be transmitted. As a result, the light emitted from the phosphor 14 passes through the main body 6, passes through the inside of the cylindrical shape, and is output toward the end where the light detection sensor 16 is disposed.

  A light detection sensor 16 is provided in the vicinity of the end of the main body 6 having a cylindrical shape. The light detection sensor 16 detects the light transmitted through the inside of the cylindrical shape. The detection signal of the light detection sensor 16 is sent to the light detector 18, converted into a corresponding electrical signal, and then sent to the calculation means 12. The calculation means 12 calculates the tritium concentration based on the acquired electrical signal.

Further, as shown in FIG. 6, a reflective film 20 may be provided between the tritium adsorbent 4 and the phosphor 14. In this case, the reflective film 20 is formed of, for example, a thin metal film so that light is reflected while transmitting the electron beam. As a result, the electron beam emitted from the tritium adsorbed on the tritium adsorbent 4 is transmitted through the reflective film 20 to cause the phosphor 14 to emit light, and the light emitted from the phosphor 14 is transmitted through the main body 6 to form a cylinder. After reaching the inside of the shape, the light is reflected by the reflective film 20 and guided toward the end where the light detection sensor 18 is provided. Thereby, since the detection light required for measurement can be suitably guided to the light detection sensor 18, good measurement accuracy can be obtained.
In FIG. 6, the reflective film 20 is provided over the entire area between the tritium adsorbent 4 and the phosphor 14, but may be provided partially.

  In addition, the range in which the reflective film 20 is provided on the inner surface of the main body 6 is such that light from the phosphor 14 provided on the surface of the main body 6 can be sufficiently transmitted to the inside and transmitted to the inside. It is good to set so that light may be efficiently condensed toward an edge part.

  As described above, according to the present embodiment, the tritium concentration is not measured by the batch method but by measuring the electron beam from the tritium adsorbed on the tritium adsorbent 4 from the tritium-containing water 2 to be measured as light. It can be calculated. Moreover, since the conventional liquid scintillation counter processes with several mL scale liquid, it is difficult to measure an object with a large capacity, and it is also difficult to measure the concentration in real time for batch processing. On the other hand, in the present embodiment, the measurement is performed by immersing in the tank in which the processing target is stored, and thus measurement is possible regardless of the capacity of the processing target. Moreover, since it can measure by light detection based on the electron beam emitted from the adsorbed tritium irrespective of batch processing, continuous monitoring is possible, and real-time measurement is also possible by increasing the processing speed.

  FIG. 7 is a schematic diagram showing an overall configuration of a tritium concentration measuring apparatus 1D according to some embodiments of the present invention.

  In this embodiment, a conductor film 22 is provided between the main body 6 and the tritium adsorbent 4 on the main body 6 immersed in the tritium-containing water 2. The conductor film 22 is a structure in which a conductor such as a metal is formed in a thin film shape, and is connected to the ground line 8. As in the embodiment described with reference to FIG. 1, a current I is induced in the conductor film 22 by an electron beam emitted from tritium adsorbed on the tritium adsorbent 4, and the current I is detected by the current detection sensor 10. Detected by.

  On the other hand, the main body 6 is made of a transmissive material containing a phosphor that can emit light by an electron beam. As described above, a part of the electron beam emitted from the tritium adsorbed on the tritium adsorbent 4 induces a current in the conductor film 22, while the rest passes through the thin conductor film 22 and enters the main body 6. The included phosphor 14 is caused to emit light.

  Then, the calculation means 12 calculates the tritium concentration based on the current value I by the current detection sensor 10 and the light intensity by the light detection sensor 16 as a physical quantity caused by the electron beam from the tritium adsorbed on the tritium adsorbent 4. To do. In this way, in this embodiment, the tritium concentration can be accurately measured by measuring both current and light.

  FIG. 8 is a schematic diagram showing an overall configuration of a tritium separation system 100 according to some embodiments of the present invention, and FIG. 9 is a flowchart showing a tritium separation method performed by the tritium separation system 100 of FIG. FIG. 10 is a graph showing an example of the transition of the tritium concentration with respect to the reaction time by the tritium adsorbent 4.

  The tritium separation system 100 (hereinafter referred to as “system 100” as appropriate) is a system that performs tritium separation based on an adsorption reaction by bringing the tritium-containing material 2 into contact with the tritium-containing water 2. In the present embodiment, in particular, the tritium adsorbing material 105 is the same material as the tritium adsorbing material 4 used in the above-described tritium concentration measuring device 1, that is, one containing hydrogen having a spinel crystal structure or lithium-containing manganese oxide. ing.

  For example, Patent Document 1 discloses at least a tritium separation process using hydrogen or lithium-containing manganese oxide having a spinel crystal structure. As described in this patent document, hydrogen or lithium-containing manganese oxide having a spinel crystal structure has an adsorption effect for a while after being brought into contact with tritium-containing water 2, but when a predetermined time has elapsed. The tritium once adsorbed has the property of being released again. For example, in the example of FIG. 10, the tritium adsorption effect is obtained well from time t0 to t1, but the tritium concentration increases after time t1. This means that the tritium once adsorbed on the tritium adsorbent 4 is released.

  The predetermined time (between t0 and t1) at which a good adsorption effect is obtained depends on various implementation conditions. Therefore, in order to carry out a stable tritium separation process, the tritium concentration is continuously monitored so that the tritium adsorbent 105 can detect a short period of time during which more tritium is adsorbed (that is, near time t1). It needs to be completed. This can be solved by the system configuration described below.

  The system 100 includes a first processing unit 110 that performs an adsorption process when the tritium-containing water 2 to be processed is brought into contact with the tritium adsorbent 105, and a process for recovering tritium released from the tritium adsorbent 105. A second processing unit 120 to be implemented, a third processing unit 130 to perform a regeneration process for recovering the adsorption performance of the tritium adsorbent 105, a treated water tank 140 for storing treated water 135 after tritium separation, and a separation A concentrated water tank 150 that stores the tritium recovered water 145 in which the tritium that has been concentrated is stored, and a regenerated liquid tank 160 that stores the regenerated liquid 155 used for the regeneration process.

  In FIG. 8, the first processing unit 110, the second processing unit 120, and the third processing unit 130 are shown as independent configurations in order to easily understand the conceptual configuration of the system 100. However, these do not necessarily have to be physically independent structures. For example, these processing units may be configured as physically different processing tanks, or may be configured as the same processing tank.

  The first processing unit 110, the second processing unit 120, and the third processing unit 130 are provided with the above-described tritium concentration measuring devices (including the various aspects) 1a, 1b, and 1c, respectively. It is comprised so that the tritium density | concentration of the various liquids stored can be measured.

  A valve 170 is provided between the first processing unit 110 and the treated water tank 140, a valve 172 is provided between the second processing unit 120 and the concentrated water tank 150, and a third A valve 174 is provided between the first processing unit 130 and the treated water tank 140, and a valve 176 is provided between the third processing unit 130 and the regenerated liquid tank 160. These valves 170, 172, 174, and 176 are configured to be able to inject various liquids between the components by adjusting the opening degree.

  The control device 200 is a control unit of the system 100, and is configured by an electronic calculator such as a computer. The control device 200 acquires the tritium concentrations in the first processing unit 110, the second processing unit 120, and the third processing unit 130 from the tritium concentration measuring devices 1a, 1b, and 1c, respectively, By transmitting a control signal for adjusting the opening degree of 170, 172, 174, 176, the overall operation of the system 100 is controlled.

  The tritium separation process is started by first taking the tritium-containing water 2 to be processed into the first processing unit 110 of the system 100 (step S1). In the 1st process part 110, the tritium adsorption process is implemented by making the tritium adsorption material 105 contact the tritium containing water 2 (step S2). The tritium adsorbing material 105 reduces the tritium concentration of the tritium-containing water 2 by adsorbing tritium from the tritium-containing water 2. Such a change in the concentration of the tritium-containing water 2 is monitored by the tritium concentration measuring device 1a.

Then, the control device 200 controls the opening and closing of the valve 170 at a timing when the measured concentration value of the tritium concentration measuring device 1a provided in the first processing unit 110 is lowered to the target value, so that the tritium-containing water after tritium separation is reduced. The treated water 6 is sent to the treated water tank 140 and the adsorption process is terminated. For example, when the tritium concentration is continuously monitored, the time change of the tritium concentration as shown in FIG. 10 is obtained. Therefore, by monitoring the behavior, the end timing of the adsorption reaction (that is, the tritium concentration in the tritium-containing water 2). It is good to determine the time (near time t1) that is expected to decrease most. Thereby, it is possible to prevent the tritium adsorbed on the tritium adsorbing material 12 from being released again into the treated water 7, and good tritium separation becomes possible.
The tritium adsorbent 12 that adsorbs tritium from the tritium-containing water 2 is transferred to the second processing unit 4 while adsorbing tritium (dashed arrow a in FIG. 8).

  Subsequently, in the second processing unit 120, the tritium adsorbent 105 transferred from the first processing unit 110 is taken in, and the valve 172 is controlled to be opened and closed by the control device 200, whereby tritium recovered water is extracted from the concentrated water tank 10. 8 is introduced. Thereby, the tritium adsorbent 105 and the tritium recovery water 8 are brought into contact with each other, and the recovery process is performed (step S3).

  Here, the tritium release from the tritium adsorbent 4 to the tritium recovered water 8 is not a typical equilibrium reaction based on the concentration difference, but is a non-equilibrium that proceeds without depending on the concentration difference after a predetermined time has elapsed since the start of the reaction. It is a reaction. For this reason, the tritium recovered water 8 has a higher tritium concentration than the tritium-containing water 2 that is the processing target of the first processing unit 3, but the release of tritium into the tritium recovered water 8 proceeds. As a result, the concentration of the tritium recovered water 8 gradually increases.

  Such a change in the concentration of the tritium recovered water 8 is also continuously monitored by the tritium concentration measuring device 1b provided in the second processing unit 120. Then, the control device 200 controls the opening and closing of the valve 170 at the timing when the measured concentration value of the tritium concentration measuring device 1b rises to the target value, whereby the concentrated tritium recovered water tritium recovered water 8 is transferred to the concentrated water tank 150. send. On the other hand, the tritium adsorbent 105 after the release of tritium is transferred to the next third processing unit 130 (broken line arrow b in FIG. 8).

In the third processing unit 130, a regeneration process is performed on the tritium adsorbent 105 transferred from the second processing unit 120 (step S4). This regeneration process is performed by bringing the regeneration liquid 155 for recovering the adsorptivity of hydrogen or lithium-containing manganese oxide having a spinel crystal structure contained in the tritium adsorbent 12 into contact with the tritium adsorbent 105.
Note that the regeneration solution 155 is an acidic solution, and as described in Patent Document 1, for example, a diluted acid having a pH of about 1 to 2 can be suitably used.

  Introduction of the regenerating liquid 155 into the third processing unit 130 is performed by controlling the valve 176 by the control device 200. After the regeneration process is completed, the regeneration liquid 155 is discharged to the processing tank 140 by the valve 174 being controlled to open and close. The third processing unit 130 recovers the adsorption performance of the tritium adsorbent 105 by performing such a regeneration process. Thereby, it is possible to repeatedly use the tritium adsorbent 105 in the system 100 while maintaining the inherent adsorption performance of the tritium adsorbent 105 (broken arrow c in FIG. 8).

  Here, the tritium remaining in the tritium adsorbent 105 may accumulate as the regenerated liquid 155 is repeatedly used for the regeneration process of the tritium adsorbent 105. Such tritium accumulation in the regenerating solution 155 can be continuously monitored by the tritium concentration measuring device 1c.

  Steps S1 to S4 described above may be repeatedly performed until the tritium concentration of the tritium-containing water 2 to be processed is equal to or lower than the target value. Moreover, when there is much capacity | capacitance of the tritium containing water 2, you may divide and repeat and divide | segment into the capacity | capacitance which can be processed with the system 1. FIG.

  As described above, in the present system 100, tritium separation from the tritium-containing water 2 can be favorably performed by continuously monitoring the tritium concentration.

  The present disclosure can be used for a tritium concentration measurement device that measures the tritium concentration of tritium-containing water and a tritium separation system that includes the tritium concentration measurement device.

DESCRIPTION OF SYMBOLS 1 Tritium concentration measuring device 2 Tritium containing water 4 Tritium adsorbent 6 Main body 8 Ground wire 10 Current detection sensor 12 Calculation means 14 Phosphor 16 Photodetector 18 Photodetector 20 Reflective film 22 Conductive film 100 Tritium separation system 105 Tritium adsorbent 110 First treatment unit 120 Second treatment unit 130 Third treatment unit 135 Treated water 140 Treated water tank 145 Tritium recovered water 150 Concentrated water tank 155 Regenerated liquid 160 Regenerated liquid tank 200 Controller

Claims (8)

A tritium concentration measuring device for measuring the tritium concentration of tritium-containing water,
The body,
A tritium adsorbent comprising hydrogen or lithium-containing manganese oxide having a spinel crystal structure, the tritium adsorbent disposed on the main body so as to be in contact with the tritium-containing water
Measuring means for measuring a physical quantity indicating an index of an electron beam from tritium adsorbed on the tritium adsorbent;
A tritium concentration measuring apparatus comprising: a calculating unit that calculates the tritium concentration based on the physical quantity. The main body is a conductor grounded via a ground wire,
The tritium concentration measuring apparatus according to claim 1, wherein the measuring unit detects a current value flowing through the ground line as the physical quantity. A plurality of the conductors are connected in parallel to the ground wire;
The tritium concentration measuring apparatus according to claim 2, wherein the measuring unit measures a total of current values flowing from the plurality of conductors to the ground line as the physical quantity. The phosphor further arranged to contact the tritium adsorbent and capable of being issued by the electron beam,
The tritium concentration measuring apparatus according to claim 1, wherein the measuring unit measures light emitted from the phosphor as the physical quantity. The main body includes a transmissive material, has an outer surface covered with the tritium adsorbent, and an inner surface covered with a reflective film, and has a cylindrical shape.
The tritium concentration measuring apparatus according to claim 4, wherein the measurement unit measures light output through the inside of the cylindrical shape as the physical quantity. The main body is made of a transmissive material containing a phosphor capable of emitting light by the electron beam,
A conductor film provided between the main body and the tritium adsorbent and connected to a ground wire;
With
The tritium concentration measuring apparatus according to claim 1, wherein the measuring unit measures a current flowing through the ground line as the physical quantity and light emitted from the phosphor. A tritium separation system for separating the tritium from the tritium-containing water,
The tritium-containing water is brought into contact with a tritium adsorbent containing hydrogen having a spinel crystal structure or a lithium-containing manganese oxide, thereby carrying out the tritium adsorption treatment,
A tritium separation system, wherein the tritium concentration measuring device according to any one of claims 1 to 6 performs monitoring by measuring the tritium concentration of the tritium-containing water.   The tritium separation system according to claim 7, wherein the adsorption process is terminated at a timing when the tritium concentration measured by the tritium concentration measuring device is equal to or lower than a preset target value.

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