JP2014016211A - System and process for removing radiation-contaminated water - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a system for removing radiation-contaminated water in which an adsorbent loaded in an absorption tower can be effectively used.SOLUTION: In the case where a piping part 220 is controlled to pass radiation-contaminated water therethrough by using one of a first adsorption tower 111 and a second adsorption tower 112 as the upstream side and the other as the downstream side and connecting them in series, the necessity of replacement of the adsorption tower on the upstream side is outputted when a measured value by a measuring part 230 provided between the first adsorption tower 111 and the second adsorption tower 112 exceeds a setting value.

Description

  The present invention relates to a radioactive contamination water decontamination system and a radioactive contamination water decontamination process for removing a plurality of types of radionuclides from radioactive contamination water, and more particularly to a technique for effectively using an adsorbent.

  Currently, a large amount of radioactive polluted water associated with an accident at a nuclear power plant exists untreated, and the storage location is limited. Therefore, it is necessary to perform appropriate treatment as quickly as possible.

  Radioactive water is allowed to be released into the environment by removing all radionuclides stipulated by law until each is below the emission threshold.

  Conventionally, in nuclear power plants, radioactive polluted water is constantly generated to cool reactors and fuel rods, and various decontamination methods for decontaminating such radioactive polluted water have been proposed. Has already been put to practical use. For example, in Patent Document 1, radioactive substance-containing wastewater oxidizing agent is added, filtered using a filtration membrane, further passed through activated carbon, and then treated with radioactive substance-containing wastewater that passes through an ion exchanger or reverse osmosis membrane. A method is disclosed.

  Further, for example, Patent Document 2 discloses a method for obtaining clean treated water by oxidizing radioactive waste liquid containing organic matter, adding an adsorbent and then filtering.

  In addition, for example, Patent Document 3 includes three or more adsorption means, and two arbitrary adsorption means are connected in series according to the order of use. A water treatment apparatus that switches repeatedly is disclosed.

  On the other hand, Non-Patent Document 1 organizes the current state of contaminated water treatment in an accident at a nuclear power plant and introduces several contaminated water treatment facilities.

JP 2008-64703 A JP-A-7-260997 Japanese Patent No. 4907585

Journal of the Atomic Energy Society of Japan Vol. 154, no. 3 (2012)

  In a conventional radioactive contaminated water treatment system, a plurality of types of adsorption towers loaded with different adsorbents are arranged in series, and the radioactive contaminated water is allowed to flow therethrough, thereby removing a plurality of radionuclides to be removed. The change in adsorption power over time is managed for each adsorption tower, and the adsorption tower whose adsorption power has dropped is replaced with a new adsorption tower as needed.

  Each adsorption tower must be replaced immediately if it becomes impossible to remove the radionuclide to be removed from the radioactively contaminated water to below the specified level.

  However, even in the adsorption tower that has reached the replacement period, the adsorption capacity remains, and there are some expensive adsorbents, so the adsorbent should be used effectively so as not to leave as much adsorption capacity as possible. If possible, the cost can be reduced and the volume of the used adsorbent can be reduced, which is very useful.

  On the other hand, when exchanging the adsorption tower, the entire system must be stopped in principle, resulting in a reduction in processing efficiency. Moreover, the exchange time varies for each adsorption tower, and it is extremely inefficient to stop the entire system every time one adsorption tower is exchanged. So, for example, if two or more adsorption towers are installed, and the valve is operated to switch to a new adsorption tower instantly, the adsorption tower can be replaced without stopping the system. It is not space efficient to always install an adsorption tower that is not used during operation.

  The present invention has been made in consideration of the conventional problems as described above. It is a first object of the present invention to provide a radioactive contaminated water decontamination system and process capable of effectively using an adsorbent loaded in an adsorption tower. It is a second object of the present invention to provide a radioactive contaminated water decontamination system and process that can replace the adsorption tower without stopping the system.

  The present invention is a radioactive contamination water decontamination system for removing radionuclides from radioactively contaminated water, wherein the first adsorption container and the second adsorption vessel are loaded with an adsorbent that adsorbs the radionuclides, and water supply of the radioactively contaminated water. A pipe, a first supply pipe connecting the water supply pipe to the water inlet of the first adsorption container, a second supply pipe connecting the water supply pipe to the water inlet of the second adsorption container, and the first A supply destination switching unit that switches between a first supply state that opens a supply pipe and closes the second supply pipe; and a second supply state that opens the second supply pipe and closes the first supply pipe; A first intermediate pipe connecting the water outlet of one adsorption container to the water inlet of the second adsorption container; and a second intermediate pipe connecting the water outlet of the second adsorption container to the water inlet of the first adsorption container And opening the first intermediate pipe and closing the second intermediate pipe From an intermediate switching unit that switches between a first intermediate state and a second intermediate state that opens the second intermediate pipe and closes the first intermediate pipe, a drain pipe to the outside, and a water outlet of the first adsorption vessel A first discharge pipe connecting to the drain pipe, a second discharge pipe connecting the water outlet of the second adsorption container to the drain pipe, and opening the first discharge pipe and closing the second discharge pipe A discharge source switching unit that switches between a first discharge state that performs and a second discharge state that opens the second discharge pipe and closes the first discharge pipe; and the first intermediate pipe and the second intermediate pipe. A measuring unit for measuring the intensity of radiation; and in a first case of passing radioactive contaminated water when in the first supply state, in the first intermediate state, and in the second discharge state, When the measured value by the measuring unit exceeds the set value, the first adsorption container is replaced. In the second supply state, in the second intermediate state, in the second intermediate state, and in the second discharge state in which the radioactive polluted water is passed by the measurement unit. An output unit that outputs that the second adsorption container needs to be replaced when the measured value exceeds a set value;

The present invention is a radioactive contamination water decontamination process in a radioactive contamination water decontamination system that removes radionuclides from radioactive contamination water, wherein the radioactive contamination water decontamination system is loaded with an adsorbent that adsorbs the radionuclides. A first adsorbing vessel, a second adsorbing vessel, a water supply pipe for radioactively contaminated water, a first supply pipe connecting the water supply pipe to a water inlet of the first adsorption container, and the water supply pipe to the second adsorption container. A second supply pipe that connects to the water inlet, a first supply state that opens the first supply pipe and closes the second supply pipe, and opens the second supply pipe and closes the first supply pipe A supply destination switching unit that switches between the second supply state, a first intermediate pipe that connects a water outlet of the first adsorption container to a water inlet of the second adsorption container, and a water outlet of the second adsorption container Connect to the inlet of the first adsorption container A second intermediate pipe that opens the first intermediate pipe and closes the second intermediate pipe; and a second intermediate state that opens the second intermediate pipe and closes the first intermediate pipe. An intermediate switching unit for switching between,
A drain pipe to the outside, a first discharge pipe connecting from the outlet of the first adsorption container to the drain pipe, and a second discharge pipe connecting from the outlet of the second adsorption container to the drain pipe A discharge source switching unit that switches between a first discharge state in which the first discharge pipe is opened and the second discharge pipe is closed, and a second discharge state in which the second discharge pipe is opened and the first discharge pipe is closed. And a measurement unit that is provided in the first intermediate tube and the second intermediate tube and measures the intensity of radiation, wherein the radioactive contaminated water decontamination process is in the first supply state, and the first intermediate tube In the first case where the radioactive contaminated water is passed through the second exhaust state, the second adsorption container needs to be replaced when the measured value by the measuring unit exceeds a set value. After the first output step for outputting a message and the replacement of the second adsorption container A first changing step for changing to a second case of passing radioactive contaminated water when the second supply state, the second intermediate state, and the first discharge state, and the second In this case, when the measured value by the measuring unit exceeds a set value, a second output step for outputting that the replacement of the first adsorption container is necessary, and after the replacement of the first adsorption container, And a second changing step for changing in the case of 1.

  The radioactive polluted water decontamination system and the radioactive polluted water decontamination process of the present invention are such that two adsorption vessels loaded with an adsorbent that adsorbs a radionuclide are connected in series with one upstream and piping between adsorption towers. Based on the intensity of the radiation in the pipe, monitor the radionuclide concentration in the liquid flowing in the pipe to determine the replacement time, and output that it is necessary to replace the adsorption container upstream. Can do. As a result, it is possible to know the state of the adsorption container to be replaced next with high accuracy by directly measuring the water discharged from the upstream adsorption container (adsorption container to be replaced next) and obtaining the concentration of the radionuclide. it can. Therefore, since the replacement time can be accurately controlled, the adsorbent loaded in the adsorption container can be used effectively.

  In addition, in the process of decontamination of radioactive contaminated water, when replacing the adsorption container, the radioactive contaminated water is passed through the adsorption container that has been used on the downstream side (adsorption container that will not be replaced this time), and adsorption is performed during that time. The container can be exchanged. Therefore, the adsorption tower can be replaced without stopping the system.

  Moreover, in the radioactive contamination water decontamination system, since the measurement unit is provided in a portion shared by the first intermediate pipe and the second intermediate pipe, even if the upstream side and the downstream side of the adsorption container are interchanged, The concentration of nuclides can be measured. This eliminates the effects of errors due to individual sensor differences and mounting conditions, so the state of the adsorption tower can be known with high accuracy, and the number of wires is reduced, eliminating the need to switch sensors each time the system is replaced, simplifying the system. Can be

  Further, in the radioactive contamination water decontamination system, the concentration of the removal target nuclide can be measured by measuring the intensity of the γ-ray having a wavelength unique to the removal target nuclide. Therefore, even when a plurality of radionuclides are mixed in the radioactively contaminated water, it is possible to accurately measure only the concentration of the removal target nuclide and simultaneously measure the concentration of the plurality of radionuclides.

  In the radioactive contamination water decontamination system, a third adsorption container is connected downstream of the second stage of two adsorption containers connected in series, and between the second stage adsorption container and the third stage adsorption container. Since the intensity of γ-rays having a wavelength specific to the radionuclide to be removed is measured, when the γ-rays are detected, the first stage adsorption vessel is almost completely saturated considering the length of the vessel. (The state in which the ability to remove the target nuclide is almost completely lost) can be determined, and the adsorbent in the adsorption container can be used up.

  Further, in the radioactive contamination water decontamination system, since the replacement timings of the adsorption units loaded with different adsorbents are adjusted to be close to each other, a plurality of adsorption units can be replaced at a time, which is efficient.

  Further, in the radioactive contamination water decontamination system, since all of the adsorption units are mounted on a container that can be transported by a trailer and connected by one or a few joints, the entire system can be replaced in a short time.

It is a schematic diagram of the adsorption | suction unit with which the radioactive contamination water decontamination system of Embodiment 1 which concerns on this invention is provided. It is a chart figure which shows the procedure of exchange of an adsorption tower. It is a schematic diagram of the adsorption | suction unit with which the radioactive contamination water decontamination system of the modification 1 which concerns on this invention is provided. It is a schematic diagram of the adsorption | suction unit with which the radioactive contamination water decontamination system of the modification 2 which concerns on this invention is provided. It is a schematic diagram of the radioactive contamination water decontamination system of the modification 3 which concerns on this invention.

<Embodiment 1>
<Configuration>
FIG. 1 is a schematic diagram of an adsorption unit 100 provided in the radioactively contaminated water decontamination system 1 according to Embodiment 1 of the present invention.

  In FIG. 1, an adsorption unit 100 is a main configuration of a radioactive contaminated water decontamination system that removes radionuclides from radioactive contaminated water, and includes an adsorption unit 110, a piping unit 120, a measurement unit 130, a switching control unit 140, and an output unit. 150. Here, FIG. 1 shows a water supply pipe A for radioactively contaminated water and a drain pipe B to the outside for the purpose of explanation. The piping unit 120 may include a water supply pipe A and a drain pipe B.

  The adsorption unit 100 can be used alone to be a radioactive contaminated water decontamination system that removes a specific radionuclide from radioactive contaminated water, or a large-scale radioactive component including a core cooling water circulation system in a nuclear power plant. It can also be part of a contaminated water decontamination system.

  The adsorption unit 110 includes a first adsorption tower 111 and a second adsorption tower 112 loaded with an adsorbent that adsorbs the radionuclide, and adsorbs the radionuclide using the adsorbent.

  The first adsorption tower 111 and the second adsorption tower 112 are adsorption containers of the same scale each loaded with the same adsorbent. Note that the adsorbents loaded in the first adsorption tower 111 and the second adsorption tower 112 are not necessarily the same adsorbent because they have the same removal ability with respect to the radionuclide assumed as the removal target.

  The pipe section 120 is composed of a water pipe made of metal or resin and a switching valve capable of switching the flow path. The first adsorbing tower 111 and the second adsorbing tower 112 are connected in series or independently, and are radioactive. A flow path for passing contaminated water is formed. Specifically, the piping unit 120 includes a first supply pipe 121, a second supply pipe 122, a supply destination switching unit 123, a first intermediate pipe 124, a second intermediate pipe 125, an intermediate switching unit 126a, an intermediate switching unit 126b, a first A discharge pipe 127, a second discharge pipe 128, and a discharge source switching unit 129 are included.

  The first supply pipe 121 connects the water supply pipe A to the water inlet of the first adsorption tower 111 via the supply destination switching unit 123.

  The second supply pipe 122 connects the water supply pipe A through the supply destination switching unit 123 to the water inlet of the second adsorption tower 112.

  The supply destination switching unit 123 includes a first supply state in which the first supply pipe 121 is opened and the second supply pipe 122 is closed, and a second supply state in which the second supply pipe 122 is opened and the first supply pipe 121 is closed. Is switched. When not in use, the supply destination switching unit 123 switches to the third supply state in which the first supply pipe 121 is closed and the second supply pipe 122 is closed.

  The first intermediate pipe 124 connects the water outlet of the first adsorption tower 111 to the water inlet of the second adsorption tower 112 through the intermediate switching unit 126b.

  The second intermediate pipe 125 connects the water outlet from the second adsorption tower 112 to the water inlet of the first adsorption tower 111 via the intermediate switching unit 126a.

  The intermediate switching units 126a and 126b work in conjunction with a first intermediate state in which the first intermediate pipe 124 is opened to close the second intermediate pipe 125, and a second intermediate pipe 125 is opened to close the first intermediate pipe 124. 2 Switch between intermediate states.

  The first discharge pipe 127 connects the water outlet of the first adsorption tower 111 to the drain pipe B via the discharge source switching unit 129.

  The second discharge pipe 128 connects the outlet port of the second adsorption tower 112 to the drain pipe B via the discharge source switching unit 129.

  The discharge source switching unit 129 includes a first discharge state in which the first discharge pipe 127 is opened and the second discharge pipe 128 is closed, and a second discharge state in which the second discharge pipe 128 is opened and the first discharge pipe 127 is closed. Is switched.

  The measurement unit 130 includes sensors 131a and 131b, which are measurement machines that measure radiation such as α-rays, β-rays, and γ-rays. In the path of the piping unit 120, the content of the removal target nuclide is determined as the type and amount of radiation. Measure based on The sensor 131a is provided in the middle of the first intermediate tube 124, and measures the intensity of radiation in the first intermediate state. The sensor 131b is provided in the middle of the second intermediate tube 125, and measures the intensity of radiation in the second intermediate state. The sensors 131a and 131b measure the intensity of γ rays having a wavelength unique to each radionuclide for each wavelength, and cancel radiation from radionuclides other than the removal target nuclide based on the intensity of the γ rays. It is desirable to measure the concentration of the target nuclide.

  The switching control unit 140 performs control so that the supply destination switching unit 123 switches to the first supply state, the intermediate switching units 126a and 126b switch to the first intermediate state, and the discharge source switching unit 129 switches to the second discharge state. Thus, the first adsorption tower 111 is set as the upstream side and the second adsorption tower 112 is set as the downstream side to form a flow path through which radioactive contaminated water flows (this state is assumed as the first case). .

  Similarly, the switching control unit 140 controls the supply destination switching unit 123 to switch to the second supply state, the intermediate switching units 126a and 126b to switch to the second intermediate state, and the discharge source switching unit 129 to switch to the first discharge state. As a result, the second adsorption tower 112 is set as the upstream side and the first adsorption tower 111 is set as the downstream side to form a flow path through which radioactive contaminated water flows (this state is the second case). To do).

  The output unit 150 outputs that the upstream adsorption column of the first adsorption column 111 and the second adsorption column 112 needs to be replaced when the measurement value by the measurement unit 130 exceeds the set value. Inform the operator etc. Here, there are various methods for notifying the operator such as displaying on a monitor, informing by voice, or lighting or blinking a patrol lamp installed in the vicinity of the adsorption tower that needs to be replaced. Any method may be used. Note that an automatic exchange device (not shown) may receive the output from the output unit 150 and automatically replace the upstream adsorption tower.

  In response to the output from the output unit 150, the operator replaces the designated adsorption tower and installs a new adsorption tower.

  After the installation of the new adsorption tower, the switching control unit 140 recognizes that the exchange of the adsorption tower has been completed by an input from an operator to an operation panel (not shown) or the like. If the first adsorption tower 111 is on the upstream side, the control in the first case is switched to the control in the second case (the second adsorption tower 112 is on the upstream side), and the second adsorption tower 112 is placed on the upstream side. The first adsorbing tower 111 is connected in series on the downstream side to form a flow path for allowing radioactive contaminated water to flow therethrough.

  Similarly, if the switching control unit 140 is in the second case (the second adsorption tower 112 is upstream), for example, before replacement, the first case (the first adsorption tower 111) is controlled from the control in the second case. Is switched to control on the upstream side, and the first adsorption tower 111 is set to the upstream side and the second adsorption tower 112 is connected to the downstream side in series to form a flow path through which radioactive polluted water flows.

  In addition, during replacement | exchange of an adsorption tower, decontamination can also be continued by connecting the adsorption tower which is not exchanged independently.

  In order to connect the adsorption towers alone, the intermediate switching units 126a and 126b have a third intermediate that closes the first intermediate pipe and closes the second intermediate pipe separately from the first intermediate state and the second intermediate state. It must be possible to switch to a state.

  Further, in the first case, when the measured value by the measuring unit 130 exceeds the set value, the switching control unit 140 switches to the second supply state by the supply destination switching unit 123, and the third switching unit 126a, 126b performs the third intermediate state. By switching to the state and controlling the discharge source switching unit 129 to maintain the first discharge state, the first adsorption tower 111 is independently connected to form a flow path through which radioactive contaminated water flows. Here, the output unit 150 outputs that the second adsorption tower 112 needs to be replaced. After the replacement of the second adsorption tower 112, the switching control unit 140 switches to the control in the second case.

  Similarly, in the second case, when the measurement value by the measurement unit 130 exceeds the set value, the switching control unit 140 switches to the first supply state by the supply destination switching unit 123, and performs the third switching by the intermediate switching units 126a and 126b. By switching to the intermediate state and controlling the discharge source switching unit 129 to maintain the second discharge state, the second adsorption tower 112 is independently connected to form a flow path through which radioactive polluted water flows. The output unit 150 outputs that the first adsorption tower 111 needs to be replaced. After the replacement of the first adsorption tower 111, the switching control unit 140 switches to the control in the first case.

<Operation>
FIG. 2 is a chart showing the procedure for exchanging the adsorption tower.

  The procedure for exchanging the adsorption tower will be described below with reference to FIG. Here, during the exchange of the adsorption tower, the decontamination is continued by connecting the non-replaced adsorption tower alone. If decontamination is not continued during the replacement of the adsorption tower, the supply destination switching unit 123 switches to the third supply state during the replacement to stop the decontamination by stopping the supply of radioactive contaminated water.

  (1) The switching control unit 140 compares the usage periods of the first adsorption tower 111 and the second adsorption tower 112 based on past history, operator input, and the like (step S1). Here, it is determined whether the use period of the first adsorption tower 111 is longer (YES) or the use period of the second adsorption tower 112 is longer (NO). When the period of use is the same, the period of use of the first adsorption tower 111 is assumed to be longer (YES) for convenience.

  (2) When the use period of the first adsorption tower 111 in (1) is longer (step S1: YES), or after replacement of the second adsorption tower 112 in (11) (step S11: YES), The switching control unit 140 performs control so that the supply destination switching unit 123 switches to the first supply state, the intermediate switching units 126a and 126b switch to the first intermediate state, and the discharge source switching unit 129 switches to the second discharge state. Thus, the first adsorption tower 111 is set as the upstream side, the second adsorption tower 112 is connected as the downstream side, and the radioactive contamination water is passed through to start decontamination (step S2).

  (3) The switching control unit 140 determines whether or not the measured value (corresponding to the concentration of the radionuclide of radioactive contaminated water) by the measuring unit 130 exceeds the set value (step S3). Decontamination is continued as long as the measured value does not exceed the set value.

  (4) When the measured value exceeds the set value (step S3: YES), the switching control unit 140 switches to the second supply state by the supply destination switching unit 123, and switches to the third intermediate state by the intermediate switching units 126a and 126b. By performing control so that the first discharge state is maintained by the switching and discharge source switching unit 129, the second adsorption tower 112 is independently connected, and the radioactive polluted water is allowed to pass through to start decontamination (step S4).

  (5) The output unit 150 outputs that the first adsorption tower 111 needs to be replaced (step S5). Here, the operator replaces the first adsorption tower 111 with a new adsorption tower.

  (6) Wait until the operator replaces the first adsorption tower 111 with a new adsorption tower (step S6). Here, the switching control unit 140 recognizes that the replacement of the adsorption tower is completed by an input from an operator to an operation panel (not shown).

  (7) When the use period of the second adsorption tower 112 in (1) is longer (step S1: NO), or after replacement of the first adsorption tower 111 in (6) (step S6: YES), The switching control unit 140 controls the supply destination switching unit 123 to switch to the second supply state, the intermediate switching units 126a and 126b to switch to the second intermediate state, and the discharge source switching unit 129 to switch to the first discharge state. Thus, the second adsorption tower 112 is set as the upstream side, the first adsorption tower 111 is set as the downstream side, and the radioactive contamination water is passed through to start decontamination (step S7).

  (8) The switching control unit 140 determines whether or not the measurement value (corresponding to the concentration of the radionuclide of radioactive contaminated water) by the measurement unit 130 exceeds the set value (step S8). Decontamination is continued as long as the measured value does not exceed the set value.

  (9) When the measured value exceeds the set value (step S8: YES), the switching control unit 140 switches to the first supply state by the supply destination switching unit 123, and switches to the third intermediate state by the intermediate switching units 126a and 126b. By performing control so that the second discharge state is maintained by the switching and discharge source switching unit 129, the first adsorption tower 111 is connected independently, and the radioactive polluted water is allowed to pass through to start decontamination (step S9).

  (10) The output unit 150 outputs that the second adsorption tower 112 needs to be replaced (step S10). Here, the operator replaces the second adsorption tower 112 with a new adsorption tower.

  (11) Wait until the operator replaces the second adsorption tower 112 with a new adsorption tower (step S11). Here, the switching control unit 140 recognizes that the replacement of the adsorption tower is completed by an input from an operator to an operation panel (not shown).

  As described above, according to the radioactive polluted water decontamination system of Embodiment 1, the replacement time of the upstream adsorption tower is determined based on the concentration of the radionuclide for the water discharged from the upstream adsorption tower. The adsorbent loaded in the tower can be used effectively.

  Further, when exchanging the adsorption tower, decontamination can be continued using one adsorption tower, so that the adsorption tower can be exchanged without stopping the system.

<Modification 1>
FIG. 3 is a schematic diagram of an adsorption unit 200 provided in the radioactively contaminated water decontamination system 2 of Modification 1 according to the present invention.

  The suction unit 200 according to the first modification is based on the configuration of the suction unit 100 according to the first embodiment, except that the piping unit 120 is changed to the piping unit 220 and the measuring unit 130 is changed to the measuring unit 230. The same as the suction unit 100 of the first embodiment.

  The piping unit 220 replaces the first intermediate pipe 124 of the first embodiment with the first upper pipe 221, the shared middle pipe 222, and the first lower pipe 223, and replaces the second intermediate pipe 125 of the first embodiment with the second upper pipe 224. The common middle pipe 222 and the second lower pipe 225 are replaced with intermediate switching sections 226a and 226b instead of the intermediate switching sections 126a and 126b of the first embodiment, and other components are the same as the piping section 120 of the first embodiment. It is the same.

  The measurement unit 230 includes a sensor 231 instead of the sensors 131a and 131b of the first embodiment.

  The shared middle pipe 222 is a portion shared by the path of the first intermediate pipe 124 and the path of the second intermediate pipe 125, and has a first opening and a second opening.

  The first upper pipe 221 connects from the water outlet of the first adsorption tower 111 to the first opening of the shared middle pipe 222 via the intermediate switching unit 226a.

  The second upper pipe 224 connects from the water outlet of the second adsorption tower 112 to the first opening of the shared middle pipe 222 via the intermediate switching unit 226a.

  The intermediate switching unit 226a opens the first upper tube 221 and closes the second upper tube 224 in the first intermediate state, and opens the second upper tube 224 in the second intermediate state. Close.

  The first lower pipe 223 connects the second opening of the shared middle pipe 222 to the water inlet of the second adsorption tower 112 through the intermediate switching unit 226b.

  The second lower pipe 225 connects the second opening of the shared middle pipe 222 to the water inlet of the first adsorption tower 111 via the intermediate switching unit 226b.

  The intermediate switching unit 226b opens the first lower tube 223 and closes the second lower tube 225 in the first intermediate state, and opens the second lower tube 225 and opens the first lower tube 223 in the second intermediate state. Close.

  The sensor 231 has both functions of the two sensors (sensors 131a and 131b) of the measurement unit 130 of the first embodiment, is provided in the middle of the shared middle pipe 222, and is radioactive with respect to radioactive polluted water in the shared middle pipe 222. Measure nuclide concentration.

  As described above, according to the radioactive contamination water decontamination system of Modification 1, the radionuclide concentration can be measured with the same sensor even if the upstream side and the downstream side of the adsorption tower are exchanged. Since the influence of errors due to the difference in state is eliminated, the state of the adsorption tower can be known with high accuracy, the number of wires is reduced, and there is no need to switch the sensor each time the adsorption tower is replaced, simplifying the system it can.

<Modification 2>
FIG. 4 is a schematic diagram of an adsorption unit 300 included in the radioactively contaminated water decontamination system 3 according to Modification 2 of the present invention.

  In the suction unit 300 of the second modification, the suction unit 110 is changed to the suction unit 310 and the measurement unit 230 is changed to the measurement unit 330 based on the configuration of the suction unit 200 of the first modification. is there.

  The adsorption unit 310 further includes a third adsorption tower 313 in addition to the configuration of the adsorption unit 110 of the first modification.

  The measurement unit 330 further includes a sensor 331 in addition to the configuration of the measurement unit 230 of the first modification.

  Similar to the first adsorption tower 111 and the second adsorption tower 112, the third adsorption tower 313 is an adsorption tower of the same scale loaded with the same adsorbent, and immediately before the drain pipe B (after the discharge source switching unit 129). ) Is inserted.

  The sensor 331 is the same sensor as the sensor 231 and is provided in a pipe immediately before the third adsorption tower 313 and measures the intensity of radiation. The sensor 331 preferably measures the intensity of γ rays having a wavelength specific to the radionuclide to be removed.

  According to the radioactive contamination water decontamination system of the second modification, when the removal target nuclide is detected by the sensor 331, the adsorption tower on the uppermost stream side is almost completely saturated (the ability to remove the removal target nuclide is high). It can be determined that the adsorption tower is almost completely eliminated), so that the adsorption tower can be used up reliably.

<Modification 3>
FIG. 5 is a schematic diagram of the radioactive polluted water decontamination system 4 of Modification 3 according to the present invention.

  The radioactive contaminated water decontamination system 4 of Modification 3 includes a plurality of adsorption units 401 to 410 equivalent to the adsorption unit 100 of Embodiment 1, the adsorption unit 200 of Modification 1, the adsorption unit 300 of Modification 2, and the like. Yes.

  The adsorption units 401 to 410 remove different types of radionuclides using various adsorbents.

  As the adsorbent used in each adsorption unit, for example, activated carbon to which a functional group such as an aminomethylphosphonic acid group is added, a zeolite-based inorganic material, or an inorganic material composed of alumina and silica can be used.

Further, the adsorbent includes cobalt ferrocyanide (ferrocyanide Co), TiO ₂ (titanium oxide) -based inorganic material having iron ferrocyanide (ferrocyanide Fe) as a main component, iodine (I ₂ ). Iodine and transuranium element adsorbent formed from supported activated carbon and chelating agent-containing activated carbon, inorganic carbon and alumina-containing adsorbent composed of Al ₂ O ₃ (alumina) (removal target: multi-element), Adsorbent (removal object: Sb, Se, Te, iodic acid) composed mainly of cesium oxide composed of CeO ₂ (cesium oxide) -based inorganic material, iodine and activated carbon composed of iodine (I ₂ ) -supported activated carbon Contained adsorbent (removal object: iodine), tannin composed of tannin-supported activated carbon and activated carbon-containing adsorbent (removal object: transuranium elements U, Np, Pu, Am Cm), reduced iron composed of reduced iron (rFe) -supported activated carbon and an activated carbon-containing adsorbent (removal object: Sb, Se, Te, multielement), aluminum-containing composed of Al (aluminum) -containing inorganic carbon-based material Carbon-based adsorbent (removal object: Sb, Se, Te, Tc), and a chelating agent-containing activated carbon in which DDTC-supported activated carbon, oxine-supported activated carbon, DTPA-supported activated carbon, and Cupperron-supported activated carbon are mixed. It is preferable that the composition comprises a super uranium element removal absorbent (removal target: super uranium element (U, Np, Pu, Am, Cm)). Here, what is described as “multi-element” as the removal target is Ag, Cd, Eu, Mn, Co, Y, Ru, Ce, Te, Ni, Zn, Rh, Nd, Sn, Sb, Tc, Pr. , Sm, Gd, V + Some or all of the transuranium elements (U, Np, Pu, Am, Cm) are targeted for removal.

  Here, the loading amount of the adsorbent is adjusted for each adsorption unit so that all replacement times of the adsorption units 401 to 410 are close to each other. For example, the amount of each adsorbent can be increased or decreased so that the replacement time is 6 months, and all of the adsorption units can be replaced at the same time. Even when the total replacement time is set to 6 months, for adsorbents with a large amount of use, the individual replacement time is set to 1 / integer of the total replacement time, such as 2 months or 3 months. It is possible to adjust so that the entire replacement time comes after several individual replacement times.

  Further, the radioactive contaminated water decontamination system 4 includes a container 420 that can be transported by a trailer. All of the adsorption units 401 to 410 are mounted on the container 420, and all of the adsorption units to be used except for spare ones are connected. It is in the state that was done.

  In addition, a joint portion 430 is provided that makes it easy to remove the connection to the water inlet in the most upstream adsorption unit 401 and the connection to the water outlet in the most downstream adsorption unit 410.

  As described above, according to the radioactively contaminated water decontamination system of the third modification, the replacement timings of the respective adsorption units are brought close to each other, and all of the adsorption units are mounted on the container and include a joint portion that can be easily connected. All the units can be moved simultaneously in a short time, reducing the time and effort required for replacement. Therefore, the amount of exposure of workers can be reduced as much as possible.

1, 2, 3, 4 Radioactive water decontamination system 100 Adsorption unit 110 Adsorption part 111 First adsorption tower 112 Second adsorption tower 120 Piping part 121 First supply pipe 122 Second supply pipe 123 Destination switching part 124 First Intermediate pipe 125 Second intermediate pipe 126a, 126b Intermediate switching section 127 First exhaust pipe 128 Second exhaust pipe 129 Discharge source switching section 130 Measuring section 131a Sensor 131b Sensor 140 Switching control section 150 Output section 200 Adsorption unit 220 Piping section 221 First 1 upper tube 222 shared middle tube 223 first lower tube 224 second upper tube 225 second lower tube 226a, 226b intermediate switching unit 230 measuring unit 231 sensor 300 adsorption unit 310 adsorption unit 313 third adsorption tower 330 measurement unit 331 sensor 401 ~ 410 Suction unit 420 Container 430 Join Part

Claims (8)

A radioactive contamination water decontamination system that removes radionuclides from radioactive contamination water,
A first adsorption vessel and a second adsorption vessel loaded with an adsorbent that adsorbs the radionuclide;
Radioactive water supply pipes,
A first supply pipe connecting the water supply pipe to the water inlet of the first adsorption container;
A second supply pipe connecting the water supply pipe to the water inlet of the second adsorption container;
A supply destination switching unit that switches between a first supply state that opens the first supply pipe and closes the second supply pipe, and a second supply state that opens the second supply pipe and closes the first supply pipe; ,
A first intermediate pipe connecting the water outlet of the first adsorption container to the water inlet of the second adsorption container;
A second intermediate pipe connecting the water outlet of the second adsorption container to the water inlet of the first adsorption container;
An intermediate switching unit that switches between a first intermediate state that opens the first intermediate tube and closes the second intermediate tube, and a second intermediate state that opens the second intermediate tube and closes the first intermediate tube;
A drain pipe to the outside,
A first discharge pipe connecting the outlet of the first adsorption container to the drain pipe;
A second discharge pipe connecting the water outlet of the second adsorption container to the drain pipe;
A discharge source switching unit for switching between a first discharge state in which the first discharge pipe is opened and the second discharge pipe is closed, and a second discharge state in which the second discharge pipe is opened and the first discharge pipe is closed; ,
A measuring unit provided in the first intermediate tube and the second intermediate tube to measure the intensity of radiation;
In the first case of passing radioactive polluted water when in the first supply state, in the first intermediate state, and in the second discharge state, the measurement value by the measurement unit exceeds a set value Sometimes, it outputs that the first adsorption container needs to be replaced, and allows the radioactive contaminated water to flow when the second supply state is present, the second intermediate state is present, and the first discharge state is present. In the second case, a radioactive decontaminated water decontamination comprising: an output unit that outputs that the second adsorption container needs to be replaced when a measured value by the measuring unit exceeds a set value system. The first intermediate tube and the second intermediate tube have a shared intermediate tube that is an integrated shared portion,
The first intermediate pipe is
The shared middle pipe;
A first upper pipe connecting the water outlet of the first adsorption container to the first opening of the shared middle pipe;
A first lower pipe connecting the second opening of the shared middle pipe to the water inlet of the second adsorption container;
The second intermediate pipe is
The shared middle pipe;
A second upper pipe connecting the water outlet of the second adsorption container to the first opening of the shared middle pipe;
A second lower pipe connecting the second opening of the shared middle pipe to the water inlet of the first adsorption container;
The intermediate switching unit
In the first intermediate state, the first upper pipe is opened and the second upper pipe is closed, and in the second intermediate state, the second upper pipe is opened and the first upper pipe is closed. A tube switching unit;
In the first intermediate state, the first lower pipe is opened and the second lower pipe is closed, and in the second intermediate state, the second lower pipe is opened and the first lower pipe is closed. It consists of a tube switching part,
The radioactive contamination water decontamination system according to claim 1, wherein the measurement unit is provided in the shared middle pipe. The measuring unit is
The radioactive contamination water decontamination system according to claim 1, wherein the intensity of γ rays having a wavelength specific to the radionuclide to be removed is measured. The radioactive contaminated water treatment system further comprises:
A third adsorption vessel loaded with an adsorbent that adsorbs the radionuclide;
The third adsorption container is inserted immediately before the discharge pipe to the next equipment,
The measurement unit further includes:
Provided in a pipe immediately before the third adsorption vessel, and measures the intensity of γ rays having a wavelength specific to the radionuclide to be removed;
The output unit is
The measurement value by the said measurement part judges that the measured value by the said measurement part exceeded the setting value, when the gamma ray of the wavelength peculiar to the radionuclide to be removed is detected in piping immediately before the said 3rd adsorption container. Radioactive contaminated water decontamination system. The radioactive contaminated water treatment system further comprises:
A plurality of adsorption units including the first adsorption container and the second adsorption container;
The radioactive polluted water decontamination system according to claim 1, wherein a loading amount of the adsorbent is adjusted for each adsorption unit so that all replacement times of the adsorption units are close to each other. The radioactive contaminated water treatment system further comprises:
It has a container that can be transported by a trailer,
All of the suction units are connected and mounted in the container;
The radioactive contaminated water treatment system further comprises:
The radioactive polluted water decontamination system according to claim 5, further comprising a joint portion that makes it easy to remove the connection to the water inlet in the most upstream adsorption unit and the connection to the water outlet in the most downstream adsorption unit. . A radioactive contamination water decontamination process in a radioactive contamination water decontamination system that removes radionuclides from radioactive contamination water,
The radioactive contamination water decontamination system is
A first adsorption vessel and a second adsorption vessel loaded with an adsorbent that adsorbs the radionuclide;
Radioactive water supply pipes,
A first supply pipe connecting the water supply pipe to the water inlet of the first adsorption container;
A second supply pipe connecting the water supply pipe to the water inlet of the second adsorption container;
A supply destination switching unit that switches between a first supply state that opens the first supply pipe and closes the second supply pipe, and a second supply state that opens the second supply pipe and closes the first supply pipe; ,
A first intermediate pipe connecting the water outlet of the first adsorption container to the water inlet of the second adsorption container;
A second intermediate pipe connecting the water outlet of the second adsorption container to the water inlet of the first adsorption container;
An intermediate switching unit that switches between a first intermediate state that opens the first intermediate tube and closes the second intermediate tube, and a second intermediate state that opens the second intermediate tube and closes the first intermediate tube;
A drain pipe to the outside,
A first discharge pipe connecting the outlet of the first adsorption container to the drain pipe;
A second discharge pipe connecting the water outlet of the second adsorption container to the drain pipe;
A discharge source switching unit for switching between a first discharge state in which the first discharge pipe is opened and the second discharge pipe is closed, and a second discharge state in which the second discharge pipe is opened and the first discharge pipe is closed; ,
Provided in the first intermediate tube and the second intermediate tube, and a measuring unit for measuring the intensity of radiation,
The radioactive contamination water decontamination process is:
In the first case where radioactive contaminated water is passed through the first supply state, the first intermediate state, and the second discharge state, the measurement value by the measurement unit has exceeded a set value. A first output step for outputting that the second adsorption container needs to be replaced;
After the replacement of the second adsorption container, the second supply state is changed to the second case in which radioactive contaminated water is passed when the second supply state, the second intermediate state, and the first discharge state are passed. 1 change step,
In the second case, when the measured value by the measuring unit exceeds a set value, a second output step for outputting that the first adsorption container needs to be replaced;
A radioactive contamination water decontamination process comprising: a second change step for changing in the first case after the replacement of the first adsorption container. In addition to the first intermediate state and the second intermediate state, the intermediate switching unit can switch to a third intermediate state that closes the first intermediate pipe and closes the second intermediate pipe,
The radioactive contaminated water decontamination process further comprises:
In the first case, when the measured value by the measuring unit exceeds a set value, the supply switching unit switches to the second supply state during the replacement of the second adsorption container, and the intermediate switching unit The first single connection step of switching to the third intermediate state by the above, and maintaining the first discharge state by the discharge source switching unit and passing the radioactive polluted water,
In the second case, when the measured value by the measuring unit exceeds a set value, the supply switching unit switches to the first supply state during the replacement of the first adsorption container, and the intermediate switching unit The radioactive contamination according to claim 7, further comprising: a second single connection step of switching to the third intermediate state by the control unit and controlling the second discharge state to be maintained by the discharge source switching unit and passing the radioactive contaminated water. Water decontamination process.

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