JP2017015542A - Tritium separation system and tritium separation method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tritium separation system and a tritium separation method that can desirably separate tritium from a tritium-containing water by an adsorption reaction.SOLUTION: The tritium separation system separates tritium from a tritium-containing water, using a tritium adsorbent containing manganese oxide with the spinel crystal structure containing hydrogen or lithium. In the system, a first processing unit brings a tritium-containing water into a tritium adsorbent and a second processing unit brings the tritium adsorbent acquired from the first processing unit into a tritium recovery water.SELECTED DRAWING: Figure 1

Description

  The present disclosure relates to a tritium separation system and a tritium separation method for separating tritium from tritium-containing water.

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 removed relatively easily with existing purification equipment 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

  Conventionally, tritium separation has been mainly performed using a distillation process as described above, and therefore, a tritium separation technique using an adsorption reaction as in Patent Document 1 has not been established. In particular, the adsorption reaction of tritium caused by hydrogen or lithium-containing manganese oxide having a spinel crystal structure disclosed in Patent Document 1 has a different behavior from a general adsorption reaction that is an equilibrium reaction due to a concentration difference. Therefore, in order to use for tritium separation, various inventive ideas are required.

  Tritium separation technology using such an adsorption reaction consumes less energy than conventional distillation processes, and tritium separation is possible with simple equipment, so establishment in the following applications is desired. . For example, in a nuclear power plant having a pressurized water nuclear reactor, tritium accumulates in the primary coolant as the primary coolant is continuously reused, resulting in an increase in worker exposure. The Fukushima Daiichi nuclear power plant, which has become a problem in recent years, generates contaminated water every day, and a large number of contaminated water tanks continue to increase on the premises. In the treatment of contaminated water, radioactive substances are being removed by a multi-nuclide removal device. However, as described above, it is difficult to separate tritium, and contaminated water containing tritium continues to increase in the site.

  At least one embodiment of the present invention has been made in view of, for example, the above problems, and an object thereof is to provide a tritium separation system and a tritium separation method that can suitably separate tritium from tritium-containing water by an adsorption reaction.

(1) A tritium separation system according to at least one embodiment of the present invention is a tritium separation system that separates tritium from tritium-containing water using a tritium adsorbent in order to solve the above-described problem. A first processing unit that contacts the tritium adsorbent; and a second processing unit that contacts the tritium adsorbent obtained from the first processing unit with tritium recovery water.

According to the configuration of (1) above, in the first processing unit, tritium contained in the tritium-containing water is adsorbed to the tritium adsorbent by bringing the tritium-containing water into contact with the tritium adsorbent. As a result, tritium is separated from the tritium-containing water. On the other hand, in the second processing unit, tritium adsorbed on the tritium adsorbent is released into the tritium recovery water. Thereby, the concentration of tritium proceeds in the tritium recovered water. In this way, in this configuration, tritium adsorbed and separated from tritium-containing water can be concentrated and extracted into tritium-recovered water, so that volume reduction treatment of tritium-containing water is possible.
Tritium-containing water may be used as the tritium-recovered water, or water that is lower or higher than the tritium concentration of the tritium-containing water may be used.

To explain supplementarily, the separation process using the above-described adsorption reaction utilizes the characteristic adsorptivity of hydrogen or lithium-containing manganese oxide having a spinel crystal structure contained in the tritium adsorbent disclosed in Patent Document 1. Please note that A general adsorption reaction is a so-called equilibrium reaction in which a separated substance moves from a high concentration side toward a low concentration. On the other hand, the adsorption reaction by the adsorbent is a non-equilibrium reaction that does not depend on the concentration difference. This characteristic property makes it possible to release the tritium adsorbed on the tritium adsorbent into the tritium recovered water having a high concentration in the second processing section. Specifically, hydrogen or lithium-containing manganese oxide having a spinel crystal structure exhibits a certain degree of adsorption performance for a predetermined period of time when brought into contact with tritium-containing water. Have Such release of tritium is performed regardless of the concentration difference. In the second processing unit, tritium is released into the high-concentration tritium recovered water by utilizing the property that the adsorbed tritium is released after a predetermined period. Thereby, the concentration of the tritium recovery water by the tritium separated from the tritium-containing water can be advanced.

  Note that the first processing unit and the second processing unit do not necessarily have a physically independent structure. For example, the first processing unit and the second processing unit may be realized as physically different processing tanks, or may be realized as the same tank.

  The tritium adsorbent may be repeatedly used in the first processing unit and the second processing unit, or may be discharged after confirming that the proper standard is satisfied if not necessary. In the former case, the tritium adsorbent may be re-used in the first processing unit after the tritium adsorbent is recovered by recovering the tritium adsorption performance.

(2) In some embodiments, in the configuration of (1), the tritium adsorbent includes hydrogen having a spinel crystal structure or lithium-containing manganese oxide.

  According to the configuration of (2), as an example of the tritium adsorbent for realizing the above configuration, hydrogen having a spinel crystal structure disclosed in the above-mentioned Patent Document 1 or lithium-containing manganese oxide is used. it can.

(3) In some embodiments, in the configuration of (1) or (2), the tritium recovery water is repeatedly used every time the tritium adsorbent is transferred from the first processing unit.

  According to the configuration of (3) above, tritium recovered water can be concentrated by repeatedly releasing tritium adsorbed on the tritium adsorbent from the tritium-containing water to the tritium recovered water. Thereby, the tritium separated from the tritium-containing water can be concentrated to a higher concentration tritium recovered water, which is advantageous for reducing the volume of the tritium-containing water.

(4) In some embodiments, in any one of the configurations (1) to (3), a third processing unit that performs a regeneration process on the tritium adsorbent obtained from the second processing unit is provided. Furthermore, the regenerated tritium adsorbent is used again in the first processing section.

  According to the configuration of (4) above, in the third processing unit, the adsorption performance can be recovered by performing a regeneration process on the tritium adsorbent used for tritium adsorption. Thereby, it can use repeatedly, ensuring the adsorption | suction performance of a tritium adsorbent favorably.

  The third processing unit does not necessarily have a structure that is physically independent from other processing units, like the first processing unit and the second processing unit described above. Further, the concentration of tritium recovered water and the regeneration process of the used tritium adsorbent may be performed simultaneously in the second processing unit.

(5) In some embodiments, in any one of the configurations (1) to (4), the first processing unit has a time set in advance corresponding to the pH value of the tritium-containing water. The contact of the tritium-containing water with the tritium adsorbent is terminated.

  According to the configuration of the above (5), in view of the property that the tritium adsorbent exhibits good adsorption performance for a predetermined period after the tritium adsorbent is brought into contact with the tritium-containing water, the adsorbing treatment with the tritium adsorbent has elapsed for the predetermined period. End at the timing. As a result, it is possible to avoid that tritium once adsorbed after the predetermined period has elapsed and to be released again into the tritium-containing water, and it is possible to satisfactorily separate tritium. Since this predetermined period corresponds to the pH value of the tritium-containing water to be treated, by setting the predetermined period in advance based on the pH value of the tritium-containing water, smooth and good tritium separation can be achieved. It can be carried out.

(6) In some embodiments, in any one of the configurations (1) to (5), the second processing unit includes a moisture reducing unit that reduces the moisture of the tritium adsorbent.

  Hydrogen or lithium-containing manganese oxide having a spinel crystal structure contained in the tritium adsorbent is a substance that is preferably wet-stored in order to maintain its adsorption performance. According to the configuration of the above (6), in view of such a property of the tritium adsorbent, the adsorption performance is intentionally lowered by reducing the water content of the tritium adsorbent by the moisture reducing unit. Thereby, the release of tritium into the tritium recovery water in the second processing unit can be promoted.

  In addition, when the water | moisture content of a tritium adsorbent falls extremely, the spinel crystal structure contained in a tritium adsorbent will change to a lambda type crystal structure, and the recovery | restoration of adsorption | suction performance by reproduction | regeneration processing will become difficult. Therefore, there is no problem when the used tritium adsorbent is discarded. However, when the tritium adsorbent is subjected to a regeneration process and reused as in the above configuration (4), for example, It is good to reduce moisture within a reproducible range.

(7) In some embodiments, in any one of the configurations (1) to (6), the tritium-containing water is surplus water of a primary coolant in a pressurized water reactor having a chemical volume control facility. .

  According to the configuration of (7) above, tritium accumulated in the primary coolant can be suitably separated by applying the above-described tritium separation system to a pressurized water reactor (PWR). In particular, in a pressurized water reactor equipped with chemical volume control equipment, it is possible to separate tritium from the surplus water of the primary coolant generated by chemical volume control so that tritium can be efficiently separated in an operating reactor. .

(8) In some embodiments, in the configuration of (7), the chemical volume control facility includes a boric acid recovery unit that recovers boric acid contained in the excess water, and the first processing unit is The recycled water that has passed through the boric acid recovery unit is supplied as the tritium-containing water.

  According to the configuration of (8) above, when the chemical volume control facility includes the boric acid recovery unit, tritium separation is performed on the reused water from which boric acid in the water has been recovered by the boric acid recovery unit. Thus, the reuse water from which the boric acid has been removed in advance is treated, so that impurities in the tritium separation process are reduced.

(9) In some embodiments, in the configuration of (7) or (8), the tritium-containing water is reused as the primary coolant after the tritium is separated by the first processing unit. Returned to the first tank to be stored as possible.

  The configuration of (9) is practical because it can be implemented with simple line connection because there are few newly added facilities because the existing pressurized water reactor facilities are used.

(10) In some embodiments, in the configuration of (8), the tritium-containing water is supplied to the boric acid recovery unit after the tritium is separated by the first processing unit. Returned to the second tank for storing water.

  The configuration (10) is also practical because it can reduce the number of devices newly added to the existing system.

(11) In some embodiments, in any one of the configurations (1) to (10), the first processing unit and the second processing unit are configured as different processing tanks.

  According to the configuration of (11) above, each processing content executed in each processing unit is executed in a physically different processing tank. That is, by realizing each processing unit in a different processing tank, it is possible to clearly separate the processing liquid used in each processing stage and to obtain good processing efficiency. For example, as described above, after tritium is adsorbed on the tritium adsorbent in the first processing unit, tritium is released from the tritium adsorbent when time elapses. It is possible to prevent the tritium separation performance from deteriorating due to the tritium once adsorbed being released into the original tritium-containing water.

(12) In some embodiments, in any one of the configurations (1) to (10), the first processing unit and the second processing unit are configured as the same processing tank.

  According to the configuration of (12) above, each processing in each processing unit is performed in the same processing tank. For example, this can function as a plurality of processing units by injecting a processing liquid corresponding to each processing into a single processing tank. In this case, the apparatus can be made small, which is advantageous.

(13) In some embodiments, in any one of the configurations (1) to (12), the tritium adsorbent has a powder shape, and the tritium is adsorbed in the first processing unit. The tritium adsorbent after being formed is separated from the tritium-containing water by at least one of a magnetic separation method, a filtered press method, and a centrifugal separation method.

  According to the configuration of (13) above, by using the powdered tritium adsorbent, the contact area with the tritium-containing water increases, and a good tritium adsorption rate can be obtained. In the first step, the tritium adsorbent after the tritium adsorption is favorably separated from the tritium-containing water by these methods.

(14) In some embodiments, in the configuration of (4), the tritium adsorbent has a powder shape, and in the third processing unit, a centrifugal separation method, a filtered press method, and The tritium adsorbent is separated from the regenerated liquid used for the regeneration process of the tritium adsorbent by at least one of magnetic separation methods.

  According to the configuration of (14), the tritium adsorbent can be satisfactorily separated from the regenerated liquid by these methods also in the third processing unit, following (13).

(15) In some embodiments, in any one of the configurations (1) to (12), the tritium adsorbent has a powder shape, and the second treatment unit includes the tritium recovered water. Is obtained by separating the tritium adsorbent from the tritium-containing water by a first membrane separator that uses as a first backwash water.

  According to the configuration of (15) above, when separating the tritium adsorbent on which tritium has been adsorbed from the tritium-containing water after the removal of tritium, the tritium recovered water used in the subsequent second treatment section is converted into the first reverse A first membrane separator used as washing water is used. As a result, the first backwash water can be made to function as tritium recovery water in the second processing section, so that it can contribute to the efficiency of the apparatus configuration, and tritium recovered by the tritium adsorbent can be recovered without waste. It can be released into water and recovered. Further, when other solutions are used as the first backwash water, mixing of impurities becomes a problem, but such a problem does not occur.

(16) In some embodiments, in the configuration of (4), the tritium adsorbent has a powder shape, and the third processing unit is used for the regeneration treatment of the tritium adsorbent. The tritium adsorbent is separated and obtained from the regenerated liquid by a second membrane separator that uses the regenerated liquid as the second backwash water.

  According to the configuration of (16) above, when the tritium adsorbent from which the tritium has been removed is separated from the regenerated liquid from which the tritium has been collected, the regenerated liquid used in the subsequent third processing unit is used as the second backwash water. A second membrane separator used as is used. Thereby, since the 2nd backwash water can function as a reproduction | regeneration liquid in a 3rd process part, it can contribute to efficiency improvement of an apparatus structure.

(17) In some embodiments, in any one of the configurations (1) to (16), the first processing unit and the second processing unit are at least one for the tritium-containing water. The at least one valve is configured to alternately perform the tritium adsorption treatment by the tritium adsorbent in each of the plurality of treatment towers. Are switched as follows.

  According to the configuration of (17) above, tritium separation is alternately performed in each of the plurality of treatment towers, so that continuous treatment can be performed temporally on the tritium-containing water to be treated. Thereby, the efficiency of the tritium separation treatment can be improved, and the treatment of a large volume of tritium-containing water can be handled.

(18) In order to solve the above-described problem, a tritium separation system according to at least one embodiment of the present invention is configured to be able to supply the above-described tritium separation system (including the various aspects described above) and the tritium-containing water from the outside. A first discharge line configured to be able to discharge the tritium-containing water from which the tritium has been separated, and a second discharge line configured to be capable of discharging the tritium recovered water.

  Since the tritium separation process using the above system requires significantly less energy consumption than the prior art, the degree of equipment freedom is high, and for example, the processing capacity and equipment scale can be designed flexibly according to needs.

(19) A portable tritium separation system according to at least one embodiment of the present invention includes the above-described tritium separation system (including the various aspects described above).

  According to the configuration of (19), it is possible to make a portable system by utilizing such characteristics. In this case, even when many tanks are distributed over a wide area, such as the contaminated water tanks that are stored on the premises of the Fukushima Daiichi Nuclear Power Station, this system enables local processing. Processing efficiency can be improved.

(20) A portable tritium separation method according to at least one embodiment of the present invention uses tritium-containing water containing a spinel crystal structure containing tritium adsorbent containing hydrogen or lithium-containing manganese oxide in order to solve the above problems. A tritium separation method for separating tritium from a first step of bringing the tritium-containing water into contact with the tritium adsorbent, and after the first step, the tritium adsorbent is separated from the tritium-containing water by a tritium concentration. A second step of contacting with high tritium recovery water.

  The method (20) can be suitably carried out by the above-described tritium separation system or portable tritium separation system (including the above-described various aspects).

  According to at least one embodiment of the present invention, a tritium separation system and a tritium separation method capable of suitably separating tritium from tritium-containing water by an adsorption reaction can be provided.

It is a schematic diagram which shows notionally the basic principle of the tritium separation system which concerns on at least 1 embodiment of this invention. It is a flowchart which shows the tritium separation method implemented by the tritium separation system of FIG. 1 for every process. 1 is a schematic diagram illustrating an overall configuration of a tritium separation system according to Example 1. FIG. FIG. 3 is a schematic diagram illustrating an overall configuration of a tritium separation system according to a second embodiment. FIG. 4 is a schematic diagram showing an overall configuration of a tritium separation system according to Example 3. It is a schematic diagram which shows the whole structure of a nuclear power plant provided with the tritium separation system which concerns on Example 4. FIG. It is a schematic diagram which shows the modification of FIG. It is a schematic diagram which shows the modification of FIG. It is a schematic diagram which shows the modification of FIG. FIG. 6 is a schematic diagram showing the overall configuration of a tritium separation system according to Example 5. It is a schematic diagram which shows one structural example of a tritium concentration measuring device. It is the sectional view on the AA line of FIG. It is a schematic diagram which shows the other structural example of a tritium concentration measuring device. It is a schematic diagram which shows the cross-sectional structure of the main body vicinity of FIG. FIG. 10 is a schematic diagram showing an overall configuration of a tritium separation system according to Example 6. FIG. 10 is a schematic diagram showing an overall configuration of a tritium separation system according to Example 7. FIG. 10 is a schematic diagram illustrating an overall configuration of a portable tritium separation system according to an eighth embodiment.

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.

  First, the basic principle of a tritium separation system according to at least one embodiment of the present invention will be described with reference to FIGS. 1 and 2. FIG. 1 is a schematic diagram conceptually showing the basic principle of a tritium separation system according to at least one embodiment of the present invention, and FIG. 2 is a flowchart showing a tritium separation method performed by the tritium separation system of FIG. It is.

  The tritium separation system 1 (hereinafter referred to as “system 1” as appropriate) is a system for separating tritium from the tritium-containing water 2. The system 1 includes a first processing unit 3 that performs an adsorption process, a second processing unit 4 that performs a recovery process, a third processing unit 5 that performs a regeneration process, and a process that stores treated water 6. A water tank 7, a concentrated water tank 9 for storing tritium recovered water 8, and a regenerated liquid tank 11 for storing a regenerated liquid 10 for performing a regeneration process are provided.

  In FIG. 1, the first processing unit 3, the second processing unit 4, and the third processing unit 5 are shown as independent configurations in order to easily understand the conceptual configuration of the system 1. However, they do not necessarily have a physically independent structure. For example, as will be described later, each of these processing units may be configured as physically different processing tanks, or may be configured as the same processing tank.

  In the system 1, tritium separation is performed by bringing the tritium adsorbent 12 into contact with the tritium-containing water 2. In particular, the tritium adsorbent 12 includes 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 is said that it moves into the spinel crystal structure and is further captured 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.

  The tritium separation process is started by first taking the tritium-containing water 2 to be processed into the first processing unit 3 (step S1). The 1st process part 3 implements an adsorption | suction process by making the acquired tritium containing water 2 contact the tritium adsorption material 12 (step S2). The tritium adsorbent 12 adsorbs tritium from the tritium-containing water 2 and reduces the tritium concentration of the tritium-containing water 2. The tritium-containing water 2 after the tritium is separated is sent to the treated water tank 7 as treated water 6. On the other hand, the tritium adsorbent 12 is transferred to the second processing unit 4 while adsorbing the tritium separated from the tritium-containing water 2 (broken arrow a in FIG. 1).

  The adsorption process in the first processing unit 3 may be terminated at a preset time corresponding to the pH value of the tritium-containing water 2 to be processed. Here, the hydrogen or lithium-containing manganese oxide having a spinel crystal structure contained in the tritium adsorbent 12 starts the adsorption reaction by contacting the tritium-containing water 2 as described in Patent Document 1, for example. It is known that, although the adsorbing effect is good for a predetermined period, the tritium once adsorbed is released, and the predetermined time depends on the pH value of the tritium-containing water 2. In view of such properties of the tritium adsorbent 12, the first processing unit 3 may calculate a predetermined time in advance from the pH value of the tritium-containing water 2 and terminate the adsorption process at the predetermined time. Thereby, the tritium adsorbed on the tritium adsorbent 12 can be prevented from being released again into the treated water 6.

  The tritium-containing water 2 taken into the system 1 may be intentionally adjusted for the end time of the tritium adsorption process in the first processing unit 3 by adjusting the pH value in advance. In addition to determining the end timing of the adsorption process based on the elapsed time of the adsorption reaction of tritium as described above, the end timing of the adsorption process is determined by continuously monitoring the change in the tritium concentration of the tritium-containing water 2. You may make it determine. In this case, the tritium concentration measuring device 136 described later is suitable for continuous monitoring of the tritium concentration.

  Subsequently, the tritium adsorbent 12 transferred from the first processing unit 3 is brought into contact with the tritium recovery water 8 in the second processing unit 4 to perform a recovery process (step S3). Here, as described above, the tritium adsorbed on the tritium adsorbent 12 has a property of being released after a predetermined period has elapsed since the start of the adsorption reaction. Such tritium release is a non-equilibrium reaction that inevitably occurs over time regardless of the concentration difference, unlike the equilibrium reaction based on the concentration difference. In step S3, tritium released from the tritium adsorbent 12 is concentrated in the tritium recovery water 8 by utilizing the unique properties of hydrogen or lithium-containing manganese oxide having such a spinel crystal structure. . As the tritium recovered water 8, tritium-containing water 2 may be used, or tritium-containing water 2 having a lower or higher tritium concentration may be used.

  After that, the concentrated tritium recovered water 8 is sent to the concentrated water tank 9, and the tritium adsorbent 12 after the tritium is released is transferred to the next third processing unit 5 (FIG. 1). Dashed arrow b).

  In the 3rd process part 5, a reproduction | regeneration process is implemented with respect to the tritium adsorption material 12 transferred from the 2nd process part 4 (step S4). This regeneration process is performed by bringing the regeneration liquid 10 for recovering the tritium adsorption performance of hydrogen or lithium-containing manganese oxide having a spinel crystal structure contained in the tritium adsorbent 12 into contact with the tritium adsorbent 12. The regenerating solution 10 is an acidic solution, and as described in Patent Document 1, for example, a dilute acid having a pH of about 1 to 2 can be suitably used. The regenerated liquid 10 is supplied from the regenerated liquid tank 11 to the third processing unit 5, and is sent to the treated water tank 7 as a waste liquid when discarded after the completion of the regenerating process.

  In the 3rd process part 5, the adsorption | suction performance of the tritium adsorption material 12 is recovered by performing such a regeneration process. This makes it possible to repeatedly use the tritium adsorbent 12 in the system 1 while maintaining the inherent adsorption performance of the tritium adsorbent 12 (broken arrow c in FIG. 1).

  Note that the above-described steps S1 to S4 may be repeatedly performed until the tritium concentration of the tritium-containing water 2 to be processed is equal to or less 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.

  The third processing unit 5 may be arbitrary. Since the third processing unit 5 performs a regeneration process for repeated use of the tritium adsorbent 12, the third processing unit 5 is omitted when, for example, the used tritium adsorbent 12 is discarded. May be. Further, the second processing unit 4 may also serve as a reproduction process.

  As described above, in the present system 1, tritium can be suitably separated from the tritium-containing water 2, and the separated tritium can be concentrated as the tritium recovery water 8. As a result, a large amount of tritium-containing water 2 having a low tritium concentration can be significantly reduced as a small amount of tritium-recovered water 8 having a high tritium concentration. In addition, such a separation process consumes much less energy than a conventional process such as a distillation method, and can greatly reduce the scale and cost of system equipment.

In the above example, a series of steps may be repeatedly performed each time the tritium-containing water 2 is taken into the system 1. Thus, when processing is carried out a plurality of times, in particular, the same tritium recovered water 8 can be repeatedly used in the second processing unit 4 to obtain a higher concentration of tritium recovered water 8. it can. This means that the volume of the tritium-containing water 2 having a large volume can be reduced and concentrated to the tritium recovered water 8 having a small volume and a high concentration.
In addition, when a series of steps are not repeatedly performed (that is, when each treatment is completed once), the tritium recovered water 8 may not be repeatedly used, or when a series of steps is repeated. Needless to say, the tritium recovery water 8 may be replaced on the way.

Next, a specific configuration example using the basic principle will be described.
In the following description, components corresponding to the components mentioned in the description of the basic principle are denoted by common reference numerals, and are equivalent to the corresponding components of the basic principle, or correspond to subordinate concepts of the corresponding components of the basic principle. Let's say that you do.

Example 1
FIG. 3 is a schematic diagram illustrating the overall configuration of the tritium separation system 1A according to the first embodiment. In the first embodiment, the first processing unit 3, the second processing unit 4, and the third processing unit 5 are configured as an adsorption tank 13, a recovery tank 14, and a regeneration tank 15 that are physically different processing tanks. ing.

  In the system 1A, the tritium-containing water 2 to be treated is first brought into contact with the tritium adsorbent 12 in the adsorption tank 13, whereby the adsorption treatment is performed. The adsorption process is continued for a predetermined period in which the tritium adsorbent 12 can exhibit a good adsorption effect. When the adsorption process is completed, the tritium-containing water 2 with reduced tritium concentration is sent to the treated water tank 7 through the discharge line 16 as treated water 6. In the discharge line 16, a pump 17 for pumping the treated water 6, a pH adjusting liquid injection unit 18 configured to be able to inject a pH adjusting liquid for adjusting the pH value of the treated water 6, and the treated water 6 And a sample collection unit 19 configured to be collected as a sample. On the other hand, the tritium adsorbent 12 having adsorbed tritium is transferred from the adsorption tank 13 to the recovery tank 14 (broken line arrow a in FIG. 3).

In the recovery tank 14, the recovery process is performed by bringing the tritium recovery material 8 into contact with the tritium adsorbent 12 transferred from the adsorption tank 13. In the recovery process, the tritium recovered water 8 is concentrated by releasing the tritium adsorbed on the tritium adsorbent 12 to the tritium recovered water 8. Thereafter, the tritium recovered water 8 is transferred to the concentrated water tank 9 through the discharge line 20. In the discharge line 20, a pump 21 for pumping the tritium recovered water 8, a pH adjusting liquid injection unit 22 configured to be able to inject a pH adjusting liquid for adjusting the pH value of the tritium recovered water 8, tritium A sample collection unit 23 configured to be able to collect the recovered water 8 as a sample is provided.
On the other hand, the tritium adsorbent 12 after the release of tritium is transferred to the regeneration tank 15 (broken line arrow b in FIG. 3).

  In the regeneration tank 15, the regeneration process is performed by bringing the regeneration liquid 10 into contact with the tritium adsorbent 12 transferred from the recovery tank 14. When the regeneration process is completed, the tritium adsorbent 13 is returned to the adsorption tank 12 again and reused (dashed arrow c in FIG. 3). On the other hand, the regenerated liquid 10 is discharged to the processing tank 7 through the discharge line 24. In the discharge line 24, a pump 25 for pumping the used regenerating liquid 10; a pH adjusting liquid injecting section 26 configured to inject a pH adjusting liquid for adjusting the pH value of the regenerating liquid 10, and A sample collection unit 27 configured to be able to collect the regenerating solution 10 as a sample is provided.

Note that tritium may be accumulated in the regenerating liquid 10 used in the regenerating tank 15 via the tritium adsorbent 12. When the tritium concentration of the regenerative liquid 10 increases, the function of the regenerative liquid 10 may deteriorate. Therefore, when the regenerative liquid 10 is used repeatedly, the tritium concentration of the regenerative liquid 10 is monitored and exceeds the allowable value. In addition, after the neutralization treatment, it may be sent to the adsorption tank 13 or the treated water tank 7.
Note that the tritium concentration measuring device 136 described later can also be used for monitoring the tritium concentration in the regenerating solution 10.

  As described above, according to the first embodiment, the adsorption process, the recovery process, and the regeneration process are performed in the physically different adsorption tank 13, the recovery tank 14, and the regeneration tank 15, respectively. That is, by realizing the first processing unit 3, the second processing unit 4, and the third processing unit 5 in different processing tanks, it is possible to clearly separate the processing liquid used in each processing stage and Processing efficiency is obtained. For example, as described above, after tritium is adsorbed to the tritium adsorbent 12 in the first processing unit 3, tritium is released from the tritium adsorbent 12 when time elapses. By transferring to another treatment tank, it is possible to prevent the tritium separation performance from deteriorating due to the tritium once adsorbed being released into the original tritium-containing water 2.

(Example 2)
FIG. 4 is a schematic diagram illustrating an overall configuration of a tritium separation system 1B according to the second embodiment. In the present embodiment, the first processing unit 3, the second processing unit 4, and the third processing unit 5 are configured as a single processing tank 28. The tritium adsorbent 12 is disposed in advance inside the treatment tank 28.

  In the system 1B, the tritium-containing water 2 to be treated is first supplied to the treatment tank 28 to be brought into contact with the tritium adsorbent 12 and the adsorption treatment is performed. At this time, the processing tank 28 functions as the first processing unit 3. Thereafter, the treated water 6 with reduced tritium concentration is sent to the treated water tank 7. This adsorption process may be performed while circulating the treated water 6 between the treated water tank 7 and the treatment tank 28.

  Subsequently, the tritium recovery water 8 is supplied from the concentrated water tank 9 with the tritium adsorbent 12 on which tritium has been adsorbed left in the treatment tank 28. Thereby, the tritium adsorbed on the tritium adsorbent 12 is released to the tritium recovery water 8 and the tritium recovery water 8 is concentrated. At this time, the processing tank 28 functions as the second processing unit 4. Thereafter, the concentrated tritium recovered water 8 is sent to the concentrated water tank 9.

  Subsequently, the regenerated liquid 10 is supplied from the regenerated liquid tank 11 with the tritium adsorbent 12 after the release of tritium remaining in the treatment tank 28. Thereby, the regeneration process of the tritium adsorbent 12 is performed. As a result, the adsorption performance of the tritium adsorbent 12 is recovered, and the above-described series of processes can be repeatedly performed. At this time, the processing tank 28 functions as the third processing unit 5. Thereafter, the regeneration solution 10 is sent to the regeneration solution tank 11, and the system 1B returns to the initial state. The regenerated liquid 10 may be sent to the treated water tank 7 after being neutralized.

  As described above, in the second embodiment, the first processing unit 3, the second processing unit 4, and the third processing unit 5 are configured as a single processing tank 28, and a process fluid corresponding to each processing is provided. By switching, a series of tritium separation processes can be performed. Therefore, the system structure can be reduced in scale.

(Example 3)
FIG. 5 is a schematic diagram illustrating an overall configuration of a tritium separation system 1C according to the third embodiment. The system 1C is characterized in that a moisture reducing unit 29 is provided in the second processing unit 4 as compared to FIG. The moisture reducing unit 29 reduces the moisture of the tritium adsorbent 12 in the second processing unit 4. As the moisture reducing unit 29, for example, a heater that reduces the moisture of the tritium adsorbent 12 by heating, a blower that reduces the moisture of the tritium adsorbent 12 by drying, or the like can be used.

  Here, hydrogen or lithium-containing manganese oxide having a spinel crystal structure contained in the tritium adsorbent 12 is a substance that is preferably wet-stored in order to maintain its adsorption performance. In view of such properties, the moisture reducing unit 29 promotes the release of tritium from the tritium adsorbent 12 in the recovery process by intentionally reducing the adsorption performance by reducing the moisture of the tritium adsorbent 12. be able to.

  When tritium is released by the moisture reducing unit 19 as described above, the reaction in which hydrogen and tritium ions present in the manganese oxide crystal of the tritium adsorbent 12 evaporate out of the crystal as water proceeds. It is also advantageous in that tritium remaining in ionic form in the material can be recovered. Further, there is an advantage that tritium recovered water with high concentration can be obtained by releasing tritium into a small amount of water.

  Since the tritium released by the moisture reducing unit 29 is typically mixed with moisture, the tritium may be collected in the concentrated water tank 9 after being condensed by the condenser 30. The water released from the tritium adsorbent 12 is also considered to contain tritium separated in the form of hydrogen gas. Therefore, in addition to the condenser 30, a recombiner for recombination is also provided, and the form of water The tritium separated in the form of hydrogen gas may be treated as a gaseous waste.

  Also, when the moisture reducing unit 29 is used, if the water content of the tritium adsorbent 12 is extremely reduced, the spinel crystal structure contained in the tritium adsorbent 12 is changed to a lambda crystal structure, and the adsorption performance is recovered by regeneration. It becomes difficult. Therefore, there is no problem when the used tritium adsorbent 12 is discarded, but when it is repeatedly used by the regeneration process, it is preferable to reduce the moisture within a range in which the tritium adsorbent 12 can be regenerated.

  In addition, when the 1st process part 3, the 2nd process part 4, and the 3rd process part 5 are comprised as a single process tank 28 like Example 2, the moisture reduction part 29 is added to the process tank 28. FIG. The tritium adsorbent 12 may be operated at the timing when the tritium adsorbed on the tritium adsorbent 12 is released to the tritium recovery water 8.

Example 4
Next, a case where the tritium separation system is applied to a nuclear power plant 100 equipped with a pressurized water reactor (PWR) will be described as an example. FIG. 6 is a schematic diagram illustrating an overall configuration of a nuclear power plant 100 including the tritium separation system 1D according to the fourth embodiment. The nuclear power plant 100 includes a primary cooling system 104 that handles a primary coolant that cools the core 102, a chemical volume control facility 106 that performs chemical volume control of the primary coolant, and various types of components generated in the nuclear power plant 100. A liquid waste treatment facility 108 for treating the waste liquid and a tritium separation system 1D according to the fourth embodiment are provided.

The chemical volume control facility 106 includes a volume control unit 110 that performs volume control of the primary coolant in the primary cooling system 104, and a second tank (coolant storage tank) that stores excess water of the primary coolant generated by the volume control. 112 and a boric acid recovery unit 114 that recovers boric acid contained in excess water. Recycled water (pure water), which is surplus water from which boric acid has been recovered, is stored in a first tank (pure water tank) 116. Moreover, what is discarded among the excess water of the chemical volume control facility 106 may be sent from the boric acid recovery unit 114 to the treated water tank 7 and discharged to the environment after confirming that it meets the appropriate standards.
It should be noted that the liquid waste from the liquid waste treatment facility 108 may also be discharged to the environment after confirming that it meets appropriate standards after being sent to the treated water tank 7.

  In general, in PWR, tritium generated in the core 102 is accumulated in the primary coolant mainly in the state of water (HTO). Tritium accumulated in the primary coolant is transferred from the primary cooling system 104 to various system facilities and distributed in the system water. When such system water is taken out as surplus water by chemical volume control, it is reused after the removal of radioactive material by the chemical volume control facility 106 or the liquid waste treatment facility 108, Or the environment is released. In the PWR plant, surplus water purification treatment is handled by the radioactive substance removal process by the chemical volume control facility 106 and the liquid waste treatment facility 108, but it is difficult to separate tritium. Such a problem can be suitably solved by introducing the system 1D according to the present embodiment.

  As shown in FIG. 6, the system 1 </ b> D is supplied with the surplus water from which boric acid has been recovered by the boric acid recovery unit 114 as a processing target via a line 118 connected to the boric acid recovery unit 114. The line 118 is provided on the downstream side of the first tank 112 or the boric acid recovery unit 114 of the chemical volume control facility 106. With such a configuration, for example, the following advantages can be obtained.

First, the primary coolant extracted from the primary cooling system 104 to the chemical volume control facility 106 is tritium water equivalent to that in the reactor core 102, and tritium exists in the plant system in the state with the highest concentration. According to this structure, since the primary coolant containing a high concentration of tritium can be processed by the tritium separation system 1D before being mixed with other waste liquid, the processing efficiency is good.
Second, the high-temperature and high-pressure primary coolant in the primary coolant system 104 has been reduced in temperature and decompressed when it is discharged to the second tank 112 in the chemical volume control facility 106, and is processed in a state that is easy to handle. it can.
Third, other radioactive substances are reduced in the purification system of the chemical volume control facility 106, and unnecessary mixing of radioactive substances into the tritium separation system 1D can be reduced. In particular, when the boric acid recovery unit 114 is provided in the chemical volume control facility 106, reused water from which other impurities are substantially removed can be treated.

The surplus water taken into the system 1D is first brought into contact with the tritium adsorbent 12 in the adsorption tank 13, whereby an adsorption process is performed. Then, after a predetermined time has elapsed, the tritium adsorbent 12 is transferred to the recovery tank 14 (broken line arrow a in FIG. 6), while surplus water from which the tritium has been separated is sent to the treated water tank 7 as treated water 6. The treated water tank 7 may be configured to monitor a radioactive substance with a dosimeter or the like, and may be released to the environment after confirming that the appropriate standard is satisfied.
The treated water 6 may be reused on condition that the water quality standard required for the primary coolant is satisfied after removing impurities and degassing.

Subsequently, the tritium adsorbent 12 transferred to the recovery tank 14 is brought into contact with the tritium recovery water 8 to perform a recovery process. As a result, tritium is released from the tritium adsorbent 12 into the tritium recovered water, and the concentration of tritium in the tritium recovered water 8 increases. Thereafter, the concentrated tritium recovered water 8 is sent to the concentrated water tank 9.
The tritium recovered water 8 stored in the concentrated water tank 9 may be subjected to treatment such as attenuation by long-term storage or stabilization by solidification.

  Subsequently, the tritium adsorbent 12 from which the tritium has been released is transferred to the regeneration tank 15 (broken line arrow b in FIG. 6), and is brought into contact with the regeneration liquid 10 supplied from the regeneration liquid tank 11, whereby the regeneration process is performed. The The tritium adsorbent 12 whose adsorption performance has been recovered by the regeneration treatment is repeatedly used again in the above process (broken line arrow c in FIG. 6).

  In addition, the tritium adsorbent 12 is deteriorated when used repeatedly, and the adsorption performance may not be sufficiently recovered even by the regeneration process. In such a case, the tritium adsorbent 12 is disposed of. In that case, the tritium adsorbent 12 is subjected to a drying process, and the adsorbing capacity is intentionally reduced, thereby adhering tritium adsorbed. Should be separated sufficiently. Thereby, the tritium contained in the tritium adsorbent 12 can be discarded in a sufficiently reduced state.

  As described above, the system 1D is configured so that the tritium-containing water 2 to be processed is mainly supplied from the boric acid recovery unit 114. In addition, in the example of FIG. The tritium-containing water 2 to be treated can also be supplied from the tank 116 via the line 120. The reused water stored in the first tank 116 is basically reused as the primary coolant by being returned to the volume control unit 110, but even if it does not satisfy the water quality standard of the primary coolant. If the environmental release standard is satisfied, environmental release may be performed. In such a case, the reused water stored in the first tank 116 is introduced into the system 1D via the line 120, so that the tritium is separated and then discharged into the treated water tank 7 to be released into the environment. Can be done.

  Subsequently, a modification of the fourth embodiment will be described with reference to FIGS. 7 to 9 are schematic views showing modifications of FIG.

  As described above, the treated water 6 that has been subjected to tritium separation in the system 1D is stored in the treated water tank 7 via the line 122 and is released to the environment after confirming that it satisfies the appropriate standard. 7, the treated water 6 may be configured to be supplied to the second tank 116 via a line 124 provided so as to branch from the line 122. In this case, since the surplus water stored in the first tank 116 is returned to the primary cooling system 104, very high water quality is required. Therefore, a purification unit 126 may be provided on the line 124. The purifying unit 126 has a function of treating impurities such as salt contained in the treated water 6 and solid or ionic manganese present by filtering, desalting, and deaeration. Such a purification unit 126 may divert existing facilities, or may be appropriately added if the existing facilities lack functions.

  Further, as shown in FIG. 8, the treated water 6 is introduced into the second tank 112 through a line 128 provided so as to branch from the line 122 through which the treated water 6 of the system 1D flows. Also good. In this configuration, since the treated water 6 is returned to the upstream side of the boric acid recovery unit 114, the system load increases not a little, but equipment newly added to the existing system can be reduced. It is a practical configuration.

  The system 1D can also be applied when the chemical volume control facility 106 does not include the boric acid recovery unit 114 as shown in FIG. In this case, the chemical volume control facility 106 includes a volume control unit 110 and a second tank 112 for storing volume control surplus water. The system 1 </ b> D is supplied with the tritium-containing water 2 to be treated via the line 130 from the second tank 112 in which surplus water taken in by the volume control unit 110 is stored. Then, the treated water 6 separated by tritium in the system 1D is returned to the second tank 112 again via the line 132. In this example, tritium is separated by the system 1D before the stored water in the second tank 112 is released to the environment, so that the release of tritium to the outside can be effectively prevented.

  As described above, according to the present embodiment, tritium accumulated in the primary coolant of the PWR plant can be suitably separated.

(Example 5)
FIG. 10 is a schematic diagram illustrating an overall configuration of a tritium separation system 1E according to the fifth embodiment. In this embodiment, the tritium-containing water 2 to be treated is first stored in the raw water storage tank 134 as raw water. The raw water storage tank 134 is provided with a tritium concentration measuring device sensor 136 for measuring the tritium concentration of tritium-containing water, and is configured so that the tritium concentration of the stored tritium-containing water 2 can be measured. The tritium adsorbent 12 has a powder shape and is stored in the adsorbent storage tank 138. The catalyst storage tank 138 is provided with an actuator (not shown) for supplying the tritium adsorbent 12 to the adsorption tank 13, and an appropriate amount for the tritium content estimated based on the measured value of the tritium concentration measuring device 136 is provided. A tritium adsorbent 12 is supplied.

  Here, a configuration example of the tritium concentration measuring device 136 will be briefly described with reference to FIGS. 11 is a schematic diagram showing one configuration example of the tritium concentration measuring device 136, FIG. 12 is a cross-sectional view taken along the line AA of FIG. 11, and FIG. 13 is a schematic diagram showing another configuration example of the tritium concentration measuring device 136. FIG. 14 is a schematic diagram showing a cross-sectional structure in the vicinity of the main body 136b of FIG.

  The tritium concentration measuring device 136 shown in FIGS. 11 and 12 is configured to continuously monitor the tritium concentration of the tritium-containing water 2 to be processed. Specifically, as shown in FIG. 11, a main body 136b provided with a tritium adsorbent 136a of the same type as that of the tritium adsorbent 12 (that is, containing hydrogen having a spinel crystal structure or lithium-containing manganese oxide) on the surface. Is immersed in tritium-containing water 2. Particularly in the present embodiment, the main body 136b is an electrode configured to include a conductor such as a metal, and the tritium adsorbent 136a is attached to the surface thereof.

  When the tritium-containing water 2 is supplied to the apparatus, tritium is adsorbed on the tritium adsorbent 136a. Here, the tritium adsorbed on the tritium adsorbent 136a is captured in a form that is greatly concentrated as compared to the tritium concentration of the tritium-containing water 2 (typically about 1000 times). Generally, the electron beam (mainly β-ray) emitted from tritium is difficult to detect because it is weak, but it is easy to detect by measuring the electron beam from tritium present in this way. Become. In particular, although the β-ray has a short reach, the tritium adsorbent 136a on which tritium is adsorbed is provided on the main body 136b, which is a conductor, and therefore electrons are induced in the main body 136b by the β-ray.

  Since the ground wire 136c is connected to the main body 136b, electrons induced in the main body 136b flow based on a potential difference from the ground, and a current I is generated. The current I is detected by a current detection sensor 136d provided on the ground line 136c. The detection value of the current detection sensor 136d corresponds to the amount of adsorption of the tritium adsorbent 136a, and is sent to the calculation means 136e which is an electronic calculator such as a computer, for example, and is calculated as the tritium concentration.

  In the embodiment shown in FIGS. 13 and 14, the tritium concentration measuring device 136 may include a phosphor 136f that can emit light by an electron beam emitted from tritium adsorbed on the tritium adsorbent 136a. Since the phosphor 136f is provided between the main body 136b and the tritium adsorbent 136a, the electron beam emitted from the tritium adsorbed on the tritium adsorbent 136a can easily reach the phosphor 136f in contact therewith. It is configured. As a result, the phosphor 136f emits light by the electron beam emitted from the tritium adsorbed on the tritium adsorbent 136a.

  The main body 136b includes a permeable material and has a cylindrical shape. In the present embodiment, in particular, the main body 136b is made of a glass material, and light emitted from the phosphor 136f can be transmitted. As a result, the light emitted from the phosphor 136f passes through the main body 136b and then passes through the inside of the cylindrical shape and is output toward the end where the light detection sensor 136g is disposed.

  A light detection sensor 136g is provided in the vicinity of the end of the cylindrical main body 136b. The light detection sensor 136g detects the light transmitted through the inside of the cylindrical shape. The detection signal of the light detection sensor 136g is sent to the light detector 136h, converted into a corresponding electrical signal, and then sent to the calculation means 136e. The calculation means 136e calculates the tritium concentration based on the acquired electrical signal.

  Returning to FIG. 10 again, the adsorption tank 13 is supplied with the tritium-containing water 2 from the raw water storage tank 134, and is supplied with the tritium adsorbent 12 from the adsorbent storage layer 138, and the adsorption treatment is performed by bringing them into contact with each other. To be implemented. Since the tritium adsorbent 12 has a powder shape, a wide contact area with the tritium-containing water 2 is obtained, and a good adsorption rate is obtained. Further, the adsorption tank 13 may be provided with a stirring mechanism (not shown), and by driving this, the tritium-containing water 2 and the tritium adsorbent 12 are well mixed to promote tritium adsorption. You may be made to do.

  The adsorption layer 13 is provided with a tritium concentration measuring device 136 as in the raw water storage tank 134. Thereby, the tritium concentration during the adsorption process can be continuously monitored, and the adsorption process can be completed at an appropriate timing while grasping the progress of the adsorption reaction. When the tritium adsorption is completed, the tritium-containing water 2 and the tritium adsorbent 12 are sent to the centrifuge 144 in a mixed state by controlling the opening and closing of the valve 142. The centrifuge 144 separates into the treated water 6 after tritium separation and the tritium adsorbent 12 on which tritium is adsorbed. The separated treated water 6 is sent to the treated water tank 7, while the tritium adsorbent 12 containing tritium is transferred to the recovery tank 14.

  In this embodiment, the tritium-containing water 2 and the tritium adsorbent 12 are separated by the centrifugal separation method using the centrifugal separator 144, but instead of or in addition to this, a filtered press method and a magnetic separation method are performed. It may be used.

  The tritium adsorbent 12 transferred to the recovery tank 14 is brought into contact with the tritium recovery water 8 supplied from the concentrated water tank 9, thereby releasing tritium to the tritium recovery water 8 and concentrating the tritium recovery water 8. Turn into.

  Here, the above-described tritium concentration measuring device 136 is also provided in the recovery tank 14 so that the tritium release process can be monitored while monitoring the tritium concentration of the tritium recovered water 8. The discharge valve 148 is controlled to open and close at the timing when the release of tritium from the tritium adsorbent 12 is completed, so that the tritium adsorbent 12 and the tritium recovered water 8 are mixed and transferred to the centrifuge 150. The

  The centrifuge 150 separates the tritium recovered water 8 having an increased tritium concentration and the tritium adsorbent 12 after the release of tritium. The tritium recovered water 8 is returned to the concentrated water tank 9 and reused. On the other hand, the tritium adsorbent 12 is transferred to the regeneration tank 15.

  In this embodiment, the tritium recovered water 8 and the tritium adsorbent 12 are separated by the centrifugal separation method using the centrifugal separator 150, but instead of or in addition to this, a filtered press method and a magnetic separation method are performed. It may be used.

  In the regeneration tank 15, the regeneration liquid 10 is taken from the regeneration liquid tank 11 into the tritium adsorbent 12 transferred from the centrifuge 150, and the regeneration process is performed. Thereby, the adsorption performance of the tritium adsorbent 12 is recovered. The regenerating tank 11 is provided with a pH value sensor 152 for detecting the pH value of the regenerating solution 10, and is configured to be able to grasp the progress of the regenerating process by monitoring the pH value. When the regeneration process is completed, the opening and closing of the valve 154 is controlled, so that the tritium adsorbent 12 and the regeneration liquid are transferred to the centrifuge 156 in a state of being mixed with each other.

  The centrifuge 156 separates the tritium adsorbent 12 and the regenerated liquid 10 in a mixed state. The separated tritium adsorbent 12 is returned to the adsorbent storage tank 138, while the regenerated liquid 10 is returned to the regenerated liquid tank 11.

  In this embodiment, the regenerating liquid 10 and the tritium adsorbent 12 are separated by the centrifugal separation method using the centrifugal separator 156, but instead of or in addition to this, a filtered press method and a magnetic separation method are used. May be.

  The used regeneration solution 10 is returned to the regeneration solution tank 11 for reuse. However, as the contact with the tritium adsorbent 12 is repeated in the regeneration solution 10, not a few impurity components are taken in. It may gradually change in quality. Therefore, the regenerative liquid tank 11 is provided with a pH value sensor 158 for detecting the pH value of the regenerative liquid 10, and the pH adjustment reagent is adjusted by adjusting the valve 160 according to the detected value of the pH value sensor. An appropriate amount of a pH adjusting reagent is supplied from the tank 162 so as to alleviate the alteration.

(Example 6)
FIG. 15 is a schematic diagram illustrating an overall configuration of a tritium separation system 1F according to the sixth embodiment. The present embodiment is characterized in that membrane separators 164 and 168 are used in place of the centrifugal separators 144 and 150 as compared with the fifth embodiment.
In addition, suppose that the same code | symbol is attached | subjected to the structure similar to Example 5, and the overlapping description is abbreviate | omitted suitably.

  The tritium adsorbent 12 and the tritium-containing water 2 that are brought into contact with each other in the adsorption layer 13 are separated in the first membrane separator 164. By passing the mixed liquid of the tritium adsorbent 12 and the tritium-containing water 2 through the membrane separator 164, only the tritium adsorbent 12 on which tritium has been adsorbed remains, and the treated tritium-containing water 2 is treated water 6. It is sent to the treated water tank 7. On the other hand, the tritium adsorbent 12 remaining in the membrane separator 164 is washed away by the first backwashing water supplied from the first backwashing water tank 166, and is returned to the recovery tank 14 together with the first backwashing water. Be transported.

  In the collection tank 14, tritium is released from the tritium adsorbent to the first backwash water in the mixture of the first backwash water and the tritium adsorbent taken in from the membrane separator 164. When the tritium release is complete, the mixture is sent to the membrane separator 168. In the membrane separator 168, only the tritium adsorbent 12 from which the tritium has been released remains by allowing the mixture to pass through, and the first backwash water in which tritium is concentrated is transferred to the first backwash water tank 166. Returned. In this way, the tritium concentration of the first backwash water increases with each cycle. On the other hand, the tritium adsorbent 12 remaining in the membrane separator 168 is washed away by the second backwashing water supplied from the second backwashing water tank 169 and put into the regeneration tank 15 together with the second backwashing water. Be transported.

  The mixture of the tritium adsorbent 12 and the second backwash water transferred to the regeneration tank 15 is separated by the centrifuge 156 after the regeneration process is completed in the regeneration tank 15. The separated second backwash water is returned to the second backwash water tank 169 via the regenerated liquid tank 11.

As described above, in this embodiment, the membrane separators 164 and 168 that use backwash water when separating the tritium adsorbent from the mixed solution are used. In the membrane separator 164, the tritium adsorbent 12 remaining in the membrane separator 164 is washed away with the first backwash water, and the tritium is released from the tritium adsorbent 12 into the first backwash water in the recovery tank 14. Thus, the first backwash water is substantially used as the tritium recovered water 8 in the above-described embodiment. As a result, it is possible to construct a system capable of concentrating tritium adsorbed on the tritium adsorbent into the tritium recovery water 8 without waste while suppressing complication of the apparatus configuration. Moreover, when other solutions are used as the first backwash water, mixing of impurities becomes a problem, but the above configuration does not cause such a problem.

  Further, in the membrane separator 168, the tritium adsorbent 12 remaining in the membrane separator 168 is washed away with the second backwash water, and the regeneration solution 10 is added to the second backwash water in the regeneration tank 14, and then the second backwash water is used. 2 backwash water is handled together with the regenerating solution 10. That is, the second backwash water is substantially used as the regenerating liquid 11 in the above-described embodiment. Thereby, complication of an apparatus configuration can be suppressed. Further, when another solution is used as the second backwash water, mixing of impurities becomes a problem, but the above configuration does not cause such a problem.

(Example 7)
FIG. 16 is a schematic diagram illustrating an overall configuration of a tritium separation system 1G according to the seventh embodiment. The present embodiment is configured to include processing towers 170A, 170B, 170C, and 170D that also serve as the first processing unit 3, the second processing unit 4, and the third processing unit 5. The processing tower 170 is configured such that a tritium adsorbent 12 is filled in a casing extending in the longitudinal direction, and various processing liquids can be injected from both ends thereof.

  The system 1G includes a plurality of processing towers 170A, 170B, 170C, and 170D having the same configuration, and these are connected in parallel to each other. A raw water storage tank 134 in which tritium-containing water 2 is stored is regenerated at one end (inlet) side 174 of the plurality of treatment towers 170 via three-way valves 176A, 176B, 176C, 176D, 178A, 178B, 178C, and 178D. A regenerated liquid tank 11 in which the liquid 10 is stored and a concentrated water tank 9 in which the tritium recovered water 8 is stored are connected to each other. On the other hand, the treated water tank 7 is connected to the other end (exit) side 180 of the plurality of treatment towers 170 via four-way valves 182A, 182B, 182C, and 182D.

  The regenerative liquid tank 11 is provided with a pH value sensor 158 for detecting the pH of the regenerative liquid 10, and by adjusting the opening of the valve 160 according to the pH measurement result of the regenerative liquid 10, The pH of the regenerating solution 10 can be adjusted by the pH adjusting reagent supplied from the pH adjusting reagent tank 162.

  The control means 184 is a control unit composed of an electronic computing unit such as a computer, for example, and opens and closes each valve by transmitting and receiving electronic signals, thereby injecting various processing liquids to and from each processing tower 170. Control as possible.

  Here, an example of control by the control means 184 will be described. First, in order to make the explanation easy to understand, only the processing tower 170A will be described.

  First, by controlling the opening and closing of the three-way valves 176A and 178A, the tritium-containing water 2 to be treated is introduced from the raw water storage tank 134 into the treatment tower 170A. The treatment tower 170A is filled with the tritium adsorbent 12, and the adsorption treatment is carried out by contacting with the supplied tritium-containing water 2. When the adsorption process is completed, the control means 184 moves the treated water 6 with reduced tritium to the treated water tank 7 by controlling the opening and closing of the four-way valve 182A. On the other hand, the tritium adsorbent 12 to which tritium has been adsorbed remains in the processing etc. 170A as it is.

  Subsequently, the control means 184 controls the opening and closing of the three-way valve 178A to introduce the tritium recovered water 8 from the concentrated water tank 9 into the processing tower 170A, and the recovery process is performed. As a result, tritium is released from the tritium adsorbent 12, and the tritium recovered water 8 is concentrated. Thereafter, the control means 184 returns the tritium recovered water 8 to the concentrated water tank 9 by controlling the opening and closing of the four-way valve 182A. Again, the tritium adsorbent 12 from which tritium has been released remains in the treatment 170A.

Subsequently, the control means 184 supplies the regenerated liquid 10 from the regenerated liquid tank 11 to the processing tower 170A by opening and closing the three-way valves 176A and 178A. Thereby, the regeneration process is performed, and the adsorption performance of the tritium adsorbent 12 is recovered. The regenerating liquid 10 used in the processing tower 170A is configured to be returned to the regenerating liquid tank 11 by controlling the opening and closing of the four-way valve 182A.
In addition, after the regeneration process is completed, the regeneration liquid 10 used in the treatment tower 170A is sent to the treated water tank 7 together with the treated water 6 by the control means 184 being controlled to open and close the four-way valve 182A. Again, the regenerated tritium adsorbent 12 remains in the processing tower 170A.

  Thus, in the processing tower 170A, a series of tritium separation processes are performed by injecting various processing liquids to the tritium adsorbent filled in the processing tower 170A. Although the processing tower 170A has been described above, a series of tritium separation processes are similarly performed in the other processing towers 170B, 170C, and 170D.

  In the present embodiment, in particular, the control means 184 is configured so that the adsorption process is continuously performed in any one of the four processing towers 170A, 170B, 170C, and 170D connected in parallel to each other. Open / close control is performed. Specifically, for example, when the adsorption process is performed in the processing tower 170A, the valves are switched so that the recovery process or the regeneration process is performed in the other processing towers 170B, 170C, and 170D. When the adsorption processing in the processing tower 170A is completed, the adsorption processing is performed in the processing tower 170B that has been performing the regeneration processing until immediately before, and the recovery processing or regeneration processing is performed in the other processing towers 170A, 170C, and 170D. Each valve is switched so that is performed.

  In this way, in the system 1G, valve switching control is performed so that the processing towers 170 on which the adsorption process is performed are alternately switched, and preferably the adsorption process is always performed on any of the processing towers 170. Thereby, the continuous separation treatment of the tritium-containing water 2 becomes possible, which is particularly advantageous when treating a large volume of the tritium-containing water 2.

(Example 8)
FIG. 17 is a schematic diagram illustrating an overall configuration of a portable tritium separation system 1H according to the eighth embodiment. In the present embodiment, the processing tank 28 configured to be usable as the first processing unit 3, the second processing unit 4, and the third processing unit 5 by injecting various processing liquids is used. Although it is common with Example 2 of this (refer FIG. 4), the raw | natural water storage tank 186 which stores the tritium containing water 2 in the exterior, and the concentrated water storage tank which takes out and stores the concentrated tritium collection | recovery water 8 187 is configured to be connectable later, and is characterized in that it is portable.
Although various valves are arranged inside the system 1H shown in FIG. 17, this arrangement is only an example, and it is only necessary to be appropriately arranged so as to realize the following configuration.

The tritium separation process using manganese oxide as described above does not require a large-scale facility such as a distillation tower as in the prior art, so the facility scale can be reduced, and such a portable system. Can be constructed as For example, when there are a large number of tanks that store tritium water over a wide area, such as a contaminated water tank in the premises of the Fukushima Daiichi Nuclear Power Station, the system 1H is moved to each tank. This is advantageous because local processing can be performed.

The system 1H is configured to be connected to an external raw water storage tank 186 so that the tritium-containing water 2 can be supplied, and the treated water 6 after the tritium is separated by the system 1H can be discharged. And a second discharge line 192 configured to be able to discharge the tritium recovered water 8 concentrated in the system 1H by being connected to the concentrated water storage tank 187.
The connection structure with the outside in the supply line 188, the first discharge line 190, and the second discharge line 192 only needs to be configured to be able to be connected to and disconnected from the connection target, and the specific structure is omitted here. .

  A specific use process of the system 1H will be described below. First, the outlet line and the inlet line of the raw water storage tank 186 storing the tritium-containing water 2 to be treated are connected to the supply line 188 and the first discharge line 190, respectively. Then, by driving a pump 194 provided between the raw water storage tank 186 and the treatment tank 28, the tritium-containing water 2 stored in the raw water storage tank 186 is supplied to the treatment tank 28, and an adsorption process is performed.

  In the treatment tank 28, the supplied tritium-containing water 2 is brought into contact with the tritium adsorbent 12 disposed in advance inside the treatment tank 28, whereby the adsorption treatment is performed. In the adsorption process, the tritium adsorbent 12 is supplied from the raw water storage tank 186 by continuing to drive the pump 194 while the adsorbing effect by the tritium adsorbent 12 is satisfactorily obtained or until the concentration of the tritium-containing water 2 reaches the target value. A circulation cycle in which tritium is separated from the tritium-containing water 2 introduced via the line 188 and the treated water 6 after separation is returned to the raw water storage tank 186 via the first discharge line 190 is repeated. By performing tritium separation while circulating the tritium-containing water 2 in this manner, it is possible to separate the large-capacity tritium-containing water 2 even in the treatment tank 28 having a relatively small capacity. That is, since the scale of the processing tank 28 can be kept small, a system capable of separating tritium with a large capacity while being suitable for portability can be realized.

  When the adsorption process is completed, the pump 194 is stopped and the remaining water in the treatment tank 28 is discharged to the raw water storage tank 186 through the discharge line 196. Subsequently, by operating the pump 198, the tritium recovery water 8 is introduced from the concentrated water tank 9 into the treatment tank 28, and the recovery process is performed. As a result, tritium is released from the tritium adsorbent 12 into the tritium recovery water 8 and the tritium recovery water 8 is concentrated. The pump 198 may also be continuously driven while the recovery process is being performed, so that the tritium recovered water 8 circulates between the processing tank 28 and the concentrated water tank 9.

  The tritium recovered water 8 is basically stored in the concentrated water tank 9, but when the concentration proceeds and the tritium concentration in the concentrated water tank 9 reaches a predetermined standard, the pump 198 is operated, It is discharged to an external concentrated water storage tank 187. As a result, a large amount of tritium-containing water is reduced in the concentrated water storage tank 187, and tritium-recovered water 8 having a high concentration of tritium is stored. The tritium collected in the concentrated water storage tank 187 can be subjected to treatment such as attenuation by long-term storage or stabilization by solidification.

  When the recovery process is completed, the pump 198 is stopped and the tritium recovered water 8 in the processing tank 28 is sent to the concentrated water tank 9 through the discharge line 200. Subsequently, by operating the pump 202, the regenerated liquid 10 is introduced from the regenerated liquid tank 11 into the treatment tank 28, and the regeneration performance is performed, whereby the adsorption performance of the tritium adsorbent 12 is recovered. During the regeneration process, the regeneration liquid 10 may be circulated between the treatment tank 28 and the regeneration liquid tank 11 by continuing the operation of the pump 202.

  When the regeneration process is completed, the regeneration liquid 10 is recovered from the processing tank 28 to the regeneration liquid tank 11 by the pump 202, and the system 1H returns to the initial state.

  In the above description of the system 1H, the case where the single processing tank 28 is provided has been described. However, a plurality of processing tanks 28 may be provided. In this case, for example, in accordance with Example 7 (see FIG. 16), the separation of the tritium-containing water 2 is controlled by controlling the injection and discharge of various treatment liquids so that the adsorption treatment is performed in any treatment tank 28. The processing may be performed continuously.

  Each line of the system 1H may be provided with a sample acquisition line for collecting a sample and a chemical injection line for adjusting the pH of various processing solutions.

  As described above, according to at least one embodiment of the present invention, a tritium separation system and a tritium separation method capable of suitably separating tritium from the tritium-containing water 2 by an adsorption reaction can be provided.

  The present disclosure relates to a tritium separation system and a tritium separation method for separating tritium from tritium-containing water.

DESCRIPTION OF SYMBOLS 1 Tritium separation system 2 Tritium containing water 3 1st process part 4 2nd process part 5 3rd process part 6 Treated water 7 Treated water tank 8 Tritium recovery water 9 Concentrated water tank 10 Regenerated liquid 11 Regenerated liquid tank 13 Adsorption Tank 14 Recovery tank 15 Regeneration tank 16, 20, 24 Discharge line 28 Treatment tank 29 Moisture reduction unit 30 Condenser 100 Nuclear power plant 102 Core 104 Primary cooling system 106 Chemical volume control facility 108 Liquid waste treatment facility 110 Volume control unit 112 Second tank 116 First tank 114 Boric acid recovery unit 126 Purification unit 134 Raw water storage tank 136 Tritium concentration measuring device 138 Adsorbent storage tanks 144, 150, 156 Centrifuges 164, 168 Membrane separator 166 First backwash Water tank 169 Second backwash water tank 170 Treatment towers 176, 178, 182 Bed 180 supply line 184 the control means 186 raw water storage tank 187 concentrated water storage tank 190 first discharge line 192 second discharge line 194,198,202 pump

Claims (20)

A tritium separation system for separating tritium from tritium-containing water using a tritium adsorbent,
A first treatment unit for bringing the tritium-containing water into contact with the tritium adsorbent;
A second processing unit for contacting the tritium adsorbent obtained from the first processing unit with tritium recovered water;
A tritium separation system comprising:   The tritium separation system according to claim 1, wherein the tritium adsorbent includes hydrogen having a spinel crystal structure or lithium-containing manganese oxide.   3. The tritium separation system according to claim 1, wherein the tritium recovery water is repeatedly used every time the tritium adsorbent is transferred from the first processing unit. A third processing unit for performing a regeneration process on the tritium adsorbent obtained from the second processing unit;
The tritium separation system according to any one of claims 1 to 3, wherein the regenerated tritium adsorbent is used again in the first processing unit.   The first processing section terminates the contact of the tritium-containing water with the tritium adsorbent for a preset time corresponding to the pH value of the tritium-containing water. 5. The tritium separation system according to claim 1.   The tritium separation system according to any one of claims 1 to 5, wherein the second processing unit includes a moisture reducing unit that reduces moisture of the tritium adsorbent.   7. The tritium separation system according to claim 1, wherein the tritium-containing water is surplus water of a primary coolant in a pressurized water reactor equipped with a chemical volume control facility. The chemical volume control facility includes a boric acid recovery unit that recovers boric acid contained in the surplus water,
The tritium separation system according to claim 7, wherein the first processing unit supplies reused water that has passed through the boric acid recovery unit as the tritium-containing water.   9. The tritium-containing water is returned to a first tank that is reusably stored as the primary coolant after the tritium is separated by the first processing unit. The tritium separation system described.   The tritium-containing water is returned to a second tank storing the surplus water supplied to the boric acid recovery unit after the tritium is separated by the first processing unit. 9. The tritium separation system according to 8.   The tritium separation system according to any one of claims 1 to 10, wherein the first processing unit and the second processing unit are configured as different processing tanks.   The tritium separation system according to any one of claims 1 to 10, wherein the first processing unit and the second processing unit are configured as the same processing tank. The tritium adsorbent has a powder shape,
In the first treatment unit, the tritium adsorbent after the tritium is adsorbed is separated from the tritium-containing water by at least one of a magnetic separation method, a filtered press method, and a centrifugal separation method. It is comprised, The tritium separation system of any one of Claim 1 to 12 characterized by the above-mentioned. The tritium adsorbent has a powder shape,
In the third processing unit, the tritium adsorbent is separated from the regenerated liquid used for the regeneration process of the tritium adsorbent by at least one of a centrifugal separation method, a filtered press method, and a magnetic separation method. The tritium separation system according to claim 4, wherein the tritium separation system is configured as follows. The tritium adsorbent has a powder shape,
The second treatment unit is characterized in that the tritium adsorbent is separated and obtained from the tritium-containing water by a first membrane separator that uses the tritium recovered water as a first backwash water. The tritium separation system according to any one of claims 1 to 12. The tritium adsorbent has a powder shape,
The third processing unit separates the tritium adsorbent from the regenerated liquid by a second membrane separator that uses the regenerated liquid used for the regeneration treatment of the tritium adsorbent as second backwash water. The tritium separation system according to claim 4, wherein the tritium separation system is obtained. The first processing unit and the second processing unit are configured as a plurality of processing towers connected in parallel to the tritium-containing water via at least one valve,
The at least one valve is configured to be switched so that the adsorption process of the tritium by the tritium adsorbent is alternately performed in each of the plurality of processing towers. The tritium separation system according to any one of 16. A tritium separation system according to any one of claims 1 to 17,
A supply line configured to be able to supply the tritium-containing water from the outside;
A first discharge line configured to discharge the tritium-containing water from which the tritium has been separated;
A tritium separation system comprising: a second discharge line configured to discharge the tritium recovered water.   A portable tritium separation system comprising the tritium separation system according to any one of claims 1 to 18. A tritium separation method for separating tritium from tritium-containing water using a tritium adsorbent containing hydrogen or lithium-containing manganese oxide having a spinel crystal structure,
A first step of bringing the tritium-containing water into contact with the tritium adsorbent;
After the first step, the second step of bringing the tritium adsorbent into contact with tritium recovered water having a higher tritium concentration than the tritium-containing water;
A method for separating tritium, comprising:

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