JP2014001991A - Radioactive nuclide removing system and radioactive nuclide removing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a radioactive nuclide removal system that can remove a plurality of kinds of radioactive nuclides from radioactive contaminated water containing a sea salt component apart from the sea salt component.SOLUTION: A radioactive nuclide removal system removes a plurality of kinds of radioactive nuclides from radioactive contaminated water. The system includes first adsorption means 41 having a first adsorbent in which a Ca low transmission film whose permeability of Ca is lower than that of Sr is formed on the surface of an internal filler containing an inorganic material that adsorbs at least Ca and Sr and second adsorption means 42 having a second adsorbent containing a TiO-based inorganic material that carries ferrocyanide Co or ferrocyanide Fe.

Description

  The present invention relates to a radionuclide removal system that removes a plurality of types of radionuclides from radioactively contaminated water, and more particularly, from strontium (Sr) and cesium (Cs) separated from sea salt components from radioactively contaminated water containing sea salt components. It is related with the technique for removing etc.

  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.

  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

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

  Radioactive water that is constantly generated in nuclear power plants during normal operation is fresh water and the types of radionuclides contained are limited, but most of the radioactive water that is currently untreated contains seawater components. It is conceivable that the radioactive nuclides contained therein are various and high in concentration, and thus cannot be treated well by the conventional decontamination method for fresh water.

  For example, when decontaminating radioactive contaminated water containing a large amount of sea salt components such as sodium (hereinafter “Na”), calcium (hereinafter “Ca”), magnesium (hereinafter “Mg”) by a conventional precipitation method, Along with a very small amount of radioactive material, a large amount of salt that is not a radioactive material is removed, and there is a problem that the total amount of pollutants that need to be treated increases many times.

  Further, for example, when radioactively contaminated water containing sea salt components is adsorbed using an adsorbent that adsorbs strontium (hereinafter “Sr”) by a conventional adsorption method, Ca and Mg, which are the same group elements, are used depending on the characteristics of the adsorbent. Are adsorbed together, the total amount of pollutants is greatly increased, and a large amount of adsorbent is required, which entails a huge cost.

  Further, for example, some nuclides such as cesium (hereinafter “Cs”) and rubidium (hereinafter “Rb”) can be adsorbed using a general adsorbent in fresh water, but in salt water, There is a problem that it is difficult to be adsorbed.

  The present invention has been made in view of the above-described conventional problems, and removes radionuclides that can be separated from sea salt components from radioactive contaminated water containing sea salt components to remove multiple types of radionuclides. A system is provided.

The present invention is a radionuclide removal system that removes a plurality of types of radionuclides from radioactively contaminated water, and includes a surface of an internal filler containing an inorganic material that adsorbs at least Ca and Sr, compared to the transmittance of Sr. A first adsorbing means having a first adsorbent having a low Ca permeability film having low permeability and a second adsorbent comprising a TiO ₂ -based inorganic material supporting ferrocyanated Co or ferrocyanated Fe. 2 adsorption means.

  In the radionuclide removal system of the present invention, the Ca low-permeability membrane is preferably a Ca alginate membrane.

  In the radionuclide removal system of the present invention, the internal filler is preferably at least one of zeolite, aluminum rimate, alumina, and silica.

  In the radionuclide removal system of the present invention, the radionuclide removal system further includes a third adsorbing unit having a third adsorbent containing a porous material, and the third adsorbent includes an iodine-supporting activated carbon and a chelate. It is preferable to contain iodine and a transuranium element adsorbent formed from the agent-containing activated carbon.

  In the radionuclide removal system of the present invention, the radionuclide removal system further includes a third adsorption unit having a third adsorbent containing a porous material, and the third adsorbent includes an adsorption containing inorganic carbon and alumina. Adsorbents mainly composed of cesium oxide, adsorbents containing iodine and activated carbon, adsorbents containing tannin and activated carbon, adsorbents containing reduced iron and activated carbon, carbon-based adsorbents containing aluminum, and transuranium element removing absorbents The configuration can be included.

  In the radionuclide removal system of the present invention, the radioactive polluted water contains salt, and the radionuclide removal system further separates the radioactive contaminated water into desalted contaminated water and concentrated salt contaminated water. A removing device, wherein the first adsorbing means, the second adsorbing means, and the third adsorbing means each include a fresh water system that adsorbs radioactive substances to the desalted contaminated water, and the concentrated salt contaminated water. It can be set as the structure by which at least 2 system | strain exists with the seawater system which adsorb | sucks a radioactive substance to object.

  In the radionuclide removal system of the present invention, the radionuclide removal system further includes a first pre-adsorption means having the first adsorbent and a second adsorbent upstream of the salt removal device. A pre-adsorption means can be provided.

The present invention is a radionuclide removal method for removing a plurality of types of radionuclides from radioactively contaminated water, wherein the surface of an internal filler containing an inorganic material that adsorbs at least Ca and Sr has a Ca content higher than that of Sr. First adsorption step of adsorbing Sr using a first adsorbent having a low Ca permeability membrane with low permeability, and second adsorption comprising ferrocyanated Co or ferrocyanated Fe-supported TiO ₂ inorganic material A second adsorption step of adsorbing Cs using an agent.

  “Adsorption” in the present invention has the meaning of capturing a substance regardless of the mechanism, and includes the meanings of “absorption” and “recovery”.

Since the radionuclide removal system of the present invention includes the first adsorbing means using the first adsorbent in which the Ca low-permeability film is formed, Sr and the like can be adsorbed without substantially adsorbing Ca. Since the second adsorbing means using the second adsorbent formed from cobalt ferrocyanide or iron ferrocyanide-supported TiO ₂ inorganic material is provided, Cs and Rb can be adsorbed in salt water. .

  Therefore, Sr, Cs, Rb, etc., which have been difficult to adsorb in salt water in the past, can be removed separately from sea salt components, so the total amount of pollutants that need to be treated increases many times. In such a situation, radioactively contaminated water containing sea salt components can be efficiently decontaminated.

It is explanatory drawing which shows the outline | summary of the adsorption | suction unit with which the radionuclide removal system of Embodiment 1 which concerns on this invention is provided. It is explanatory drawing which shows the outline | summary of a 1st adsorbent. It is explanatory drawing which shows the manufacturing method of the 1st adsorbent of this embodiment. It is an enlarged view which shows the detailed structure of the front-end | tip part of a dripping nozzle. It is a block diagram which shows the structure of the radionuclide removal system of Embodiment 2 which concerns on this invention. It is explanatory drawing which described on the periodic table the nuclide which can be decontaminated by the radionuclide removal system of Embodiment 2, and the nuclide which was actually tested and confirmed that it can decontaminate.

<Embodiment 1>
<Outline of adsorption unit>
FIG. 1 is an explanatory diagram showing an outline of an adsorption unit 40 provided in the radionuclide removal system of Embodiment 1 according to the present invention.

  In FIG. 1, an adsorption unit 40 is a main configuration of a radionuclide removal system that removes a plurality of types of radionuclides from radioactively contaminated water, and includes a first adsorption unit 41, a second adsorption unit 42, and a third adsorption unit 43. Including. The adsorption unit 40 may be a radionuclide removal system that removes a plurality of types of radionuclides from radioactively contaminated water containing sea salt components that are used alone and temporarily stored. It can also be part of a large-scale radioactive contaminated water treatment system including a circulatory system.

  The first adsorption means 41 is composed of one or a plurality of adsorption towers having a first adsorbent newly developed by the present inventors, and can adsorb and remove Sr from radioactive polluted water, compared with Sr. Does not adsorb Ca and Mg.

  FIG. 2 is an explanatory diagram showing an outline of the first adsorbent.

  In FIG. 2, the first adsorbent 29 is a group of particles 30 having a particle diameter of about 1 to 2 mm, for example. The individual particles 30 include an inner filler 31 containing an inorganic material that adsorbs at least Ca and Sr, and a Ca low-permeability film having a lower Ca permeability than the Sr permeability formed on the surface of the inner filler 31. 32.

  For the internal filler 31, for example, a zeolite-based inorganic material or an inorganic material composed of alumina and silica can be used. Here, the internal filler 31 may be a material having a high ability to adsorb Sr in an aqueous solution at least, so the ability to adsorb Ca may be low, but both of these elements (Ca and Sr) are 2A alkaline. Since it belongs to earth metals and the elements of the same group are very similar in chemical properties, a material having a high ability to adsorb Sr inevitably contains not only Ca but also Mg belonging to 2A alkaline earth metal. High ability to adsorb.

  Further, the internal filler 31 may be titania-based, silica-based, alumina-based, or a titania-alumina-based or silica-alumina-based composite of these, and may be aluminum, yttrium, bismuth, chromium, iron, indium, Gallium, lead, beryllium, copper, cobalt, cadmium, zinc and nickel phosphates can also be used.

  In particular, silica-alumina A-type zeolite or X-type zeolite is recommended as the internal filler 31, and among these, sodium-A type zeolite having a pore diameter of about 4 angstroms is recommended.

The Ca low-permeability membrane 32 is, for example, a Ca alginate membrane, and a Ca alginate membrane having an appropriate membrane pressure can be generated on the surface of the zeolite powder by dropping an alginate solution containing zeolite powder into the CaCl ₂ solution.

  The Ca alginate membrane is used in sea salt component-mixed water 33 such as RO concentrated water produced using seawater or a reverse osmosis membrane, hardly allows Ca and Mg to permeate, and selectively allows Sr to permeate. This has been confirmed by experiments by the present inventors. Therefore, in the particles 30, the Ca low-permeable film 32 on the surface does not allow Ca and Mg to approach the internal filler 31, and thus Sr is selectively adsorbed on the internal filler 31.

The first adsorbent 29 selectively adsorbs Sr to substances such as Na ⁺ , Cl ⁻ , SO ₄ ²⁻ , HCO ₃ ⁻ , and HCO ₃ ⁻ that are present in the sea salt component mixed water 33. It has also been confirmed that it does not prevent it.

  Further, it was confirmed that the first adsorbent 29 adsorbs a small amount of Mg only at the initial stage of operation. However, there is no problem in operation, and Mg will not be adsorbed after the initial stage of operation.

  It has also been confirmed that even when a RO membrane (reverse osmosis membrane) scale-preventing chelating agent coexists in seawater, the Sr removal rate of the first adsorbent 29 is hardly affected.

  Moreover, as a result of investigating the influence which the concentration change (seawater ratio 1-5 times concentration) of the seawater salt component has on the Sr removal rate of the first adsorbent 29, there is a tendency that the Sr removal rate slightly decreases on the high concentration side However, it has been confirmed that an Sr removal rate of 65% or more at the 1-fold concentration can be maintained.

  In addition, the manufacturing method of the 1st adsorption agent 29 is mentioned later.

The second adsorbing means 42 is a second adsorbent containing a TiO ₂ (titanium oxide) -based inorganic material supported mainly by ferrocyanide cobalt (ferrocyanide Co) or iron ferrocyanide (ferrocyanide Fe). And adsorbs Cs and Rb. By using the second adsorbent, the second adsorbing means 42 can adsorb and remove Cs and Rb from radioactive polluted water regardless of whether it is fresh water or salt water. The radionuclide Cs134, Cs137, Rb86, etc. can be removed from the radioactively contaminated water so as to be below the emission standard. Here, the release standard is, for example, a standard value indicated by the Special Measures Act for Countermeasures against Contamination of Radioactive Substances enforced on January 1, 2012. Specifically, the release standard or lower is 60 Bq / s in Cs134 in the case of cesium. L or less, Cs137 with 90 Bq / L or less, and when both exist, the fractional sum is 1 or less.

  The third adsorption means 43 is composed of one or a plurality of adsorption towers having a third adsorbent containing a porous material such as activated carbon, and removes radionuclides that cannot be removed by the first adsorption means 41 and the second adsorption means 42.

Here, the third adsorbent preferably contains iodine and a transuranium element adsorbent formed from iodine (I ₂ ) -supported activated carbon and chelating agent-containing activated carbon. The 3rd adsorption | suction means 43 can adsorb | suck and remove the transuranium element containing an iodine by using the said iodine and transuranium element adsorption agent.

  In the present invention, it is only necessary that the radionuclide such as Sr, Cs, and Rb, which has conventionally been difficult to adsorb in salt water, be separated from the sea salt component and removed. The minimum structure which consists of the 1st adsorption | suction means 41 and the 2nd adsorption | suction means 42 which do not include the means 43 may be sufficient.

  The third adsorbent preferably contains various adsorbents that can adsorb and remove radionuclides that cannot be removed by the configuration mainly composed of the first adsorbing means 41 and the second adsorbing means 42. The third adsorption means 43 can adsorb and remove various radionuclides by a plurality of adsorption towers using the above-mentioned various adsorbents individually or mixed.

For example, the third adsorbent is composed of inorganic carbon composed of inorganic carbon and Al ₂ O ₃ (alumina), an alumina-containing adsorbent (removal target: multielement), and a CeO ₂ (cesium oxide) inorganic material Adsorbent mainly composed of cesium oxide (removal object: Sb, Se, Te, iodic acid), iodine composed of iodine (I ₂ ) -supported activated carbon and adsorbent containing activated carbon (removal object: iodine), tannin-supported activated carbon Adsorbent containing tannin and activated carbon composed of (removal object: transuranium elements U, Np, Pu, Am, Cm), and reduced iron and activated carbon-containing adsorbent composed of reduced iron (rFe) -supported activated carbon (removal object: Sb, Se, Te, multi-element), an aluminum-containing carbon-based adsorbent composed of an Al (aluminum) -containing inorganic carbon-based material (removal object: Sb, Se, Te, Tc), and Transuranium element removal absorbent composed of chelating agent-containing activated carbon obtained by mixing DDTC-supported activated carbon, Oxine-supported activated carbon, DTPA-supported activated carbon, and Cupperron-supported activated carbon (removal target: superuranium elements (U, Np) , Pu, Am, Cm)).

Here, the aluminum-containing carbon-based adsorbent is generally sold. DDTC is sodium diethyldithiocarbamate represented by the molecular formula C ₅ H ₁₀ NS ₂ Na, and is manufactured and sold as a reagent by many manufacturers. DDTC is diethyldithiocarbamic acid represented by the molecular formula C ₁₀ H ₁₇ Cl ₂ NOS, and is manufactured and sold by many manufacturers. Moreover, what has described the removal target as "multi-element" is Ag, Cd, Eu, Mn, Co, Y, Ru, Ce, Te, Ni, Zn, Rh, Nd, Sn, Sb, Tc, Pr, Part or all of Sm, Gd, V + transuranium elements (U, Np, Pu, Am, Cm) are targeted for removal.

  The first adsorbing means 41, the second adsorbing means 42, and the third adsorbing means 43 cooperate with each other in the human body and the environment among radionuclides that are assumed to leak from the reactor containment vessel in the event of a nuclear reactor accident. It is preferable to remove all the radionuclides to be removed, which are considered to have a negligible effect on the radioactivity. By decontaminating radioactive contaminated water by removing all radionuclides to be removed to a level below the emission standard, it is possible to obtain clean treated water with a radioactivity level that is low enough to be released into the environment. it can. In FIG. 1, it is described that the processing is performed in the order of the first suction means 41, the second suction means 42, and the third suction means 43, but the processing order is considered in consideration of processing efficiency and the like at the time of implementation. You may change suitably.

<Method for producing first adsorbent>
FIG. 3 is an explanatory view showing a method for producing the first adsorbent of the present embodiment.

  In FIG. 3, the first adsorbent manufacturing apparatus 100 includes a dropping nozzle apparatus 1 and a gelling apparatus 2.

  The dropping nozzle device 1 includes a raw material pipe 3 that feeds the raw material solution, a multiple dropping nozzle 4 connected to the raw material pipe 3, and an air pipe 5 that blows air to each dropping nozzle 4.

  The raw material solution is sent to each dropping nozzle 4 through the raw material pipe 3, and the air controlled so as to be intermittently blown from the air pipe 5 is blown to each dropping nozzle 4.

  Here, the raw material solution is a solution in which Sr adsorbent and alginic acid (Algi) are mixed. In the present embodiment, A-type zeolite is used as the Sr adsorbent.

  The gelling apparatus 2 includes a container 21 and a gelling solution 22 stored in the container 21.

  The container 21 only needs to have corrosion resistance to the gelling solution 22 and the raw material solution.

The gelling solution 22 uses CaCl ₂ in this embodiment. Here, the water surface of the gelling solution 22 is disposed so as to face each dropping nozzle 4.

  FIG. 4 is an enlarged view showing a detailed structure of the tip portion of the dropping nozzle 4.

  As shown in FIG. 4, the dripping nozzle 4 has a double nozzle structure, and the raw material solution flows through the inner flow path 12 in the inner pipe 11, and is formed by the outer pipe 13 and the inner pipe 11. The air controlled so as to be intermittently blown through the formed outer flow path 14 flows. Further, since the outer pipe 13 is gradually becoming smaller in diameter at the outlet end, the outer flow path 14 becomes narrower, and the air flow 15 is blown out intermittently in a direction toward the central axis of the dropping nozzle 4.

  On the other hand, the raw material solution discharged from the inner flow path 12 is cut into small particles by the air flow 15 that is intermittently blown out, and each fragment is spheroidized by the surface tension into droplets 6 and falls in the vertical direction. .

Accordingly, the droplet 6 dropped from each dropping nozzle 4 falls vertically toward the water surface of the gelling solution 22 and slowly sinks into the solution of the gelling solution 22, and alginic acid on the surface of the droplet 6 is removed. It reacts with the CaCl _{2 of the} gelation solution 22 to form a Ca alginate film, and the resulting gel sphere 7 is gelled only on the surface and accumulates at the bottom of the container 21.

  The accumulated gel spheres 7 collected are collected from the container 21 (gel sphere collection 8) and dried by a dryer (not shown) to complete the first adsorbent 29.

  As described above, according to the radionuclide removal system of Embodiment 1, it is possible to separate and remove Sr, Cs, and Rb, which have conventionally been difficult to adsorb in salt water, from sea salt components. Therefore, it is possible to efficiently decontaminate radioactive polluted water containing sea salt components without causing a situation in which the total amount of pollutants that require water increases many times.

<Embodiment 2>
FIG. 5 is a block diagram showing a configuration of a radionuclide removal system 200 according to Embodiment 2 of the present invention.

  In FIG. 5, the radionuclide removal system 200 has separated the salt from the contaminated contaminated water, the pretreatment line 201 including the circulation system of the core cooling water and the separation of the salt from the accumulated contaminated water with the occurrence of the nuclear reactor accident. A fresh water treatment line 202 for treating the demineralized water at the time, and a salt water treatment line 203 for treating the concentrated seawater.

  In the pretreatment line 201, the core cooling water containing salt injected into the nuclear reactor 211 due to the nuclear reactor accident becomes radioactive contaminated water 212 containing various types of radionuclides and discharged outside the nuclear reactor 211. Subsequently, the oil content of the radioactive polluted water 212 is removed by the oil removing device 213, Cs is removed by the Cs removing device 214, Sr is removed by the Sr removing device 215, and the salt content is removed by the salt removing device 216.

  Here, the Cs removal device 214 has the same configuration as the second suction means 42 of the suction unit 40 of the first embodiment, and the Sr removal device 215 has the same configuration as the first suction means 41 of the suction unit 40 of the first embodiment. When the Cs removing device 214 and the Sr removing device 215 are combined, the suction unit 40 has a minimum configuration. Note that the Cs removing device 214 and the Sr removing device 215 are disposed upstream of the salt removing device 216, and a part of the Cs removing device 214 and the Sr removing device 215 are preliminarily separated before being separated into fresh water and concentrated seawater by the salt removing device 216. Since it is a preliminary adsorption means for removing the radionuclide, the Cs removing device 214 and the Sr removing device 215 are not necessarily required.

  The fresh water 221 from which the salt content has been removed by the salt content removal device 216 is temporarily stored in the treated water temporary storage tank 217, and a part of the fresh water 221 is again injected into the reactor 211 through the return pipe 219 via the buffer 218. The rest is fed from the fresh water line 222 to the fresh water treatment line 202.

  On the other hand, the concentrated salt water 233 generated when the salt content is removed by the salt content removal device 216 is temporarily stored in the primary concentrated salt water storage tank 225 and further concentrated by evaporating the water in the evaporator 226. The concentrated salt water 233 concentrated in the evaporator 226 is temporarily stored in the secondary concentrated salt water storage tank 232, a part of the concentrated salt water 233 is returned to the primary concentrated salt water storage tank 225 through the sea water line 234, and the remainder of the concentrated salt water 233 is stored in the sea water line. 235 to the seawater processing line 203.

  The steam generated in the evaporator 226 is cooled to become fresh water 221 and stored in the evaporator treated water storage tank 227. A part of the fresh water 221 is injected again into the nuclear reactor 211 through the return pipe 219, and the remainder of the fresh water 221 is obtained. The fresh water line 222 is introduced into the fresh water processing line 202.

  In addition, since wastewater containing salt is generated by washing the equipment in the evaporator 226 or the evaporator treated water storage tank 227, the salt water is desalted by the salt removal device 228, and then the concentrated salt water is returned to the primary concentrated salt water storage tank 225. The fresh water is stored in the makeup water supply facility 229 and appropriately supplied to the evaporator 226 and the evaporator treated water storage tank 227, and is used again for cleaning the equipment.

  The configurations of the fresh water processing line 202 and the salt water processing line 203 are the same as the configurations of the first adsorption means 41, the second adsorption means 42, and the third adsorption means 43 of the adsorption unit 40 of the first embodiment. However, conditions such as the order of use, concentration, and treatment time of the adsorbent are optimized when the freshwater treatment line 202 treats freshwater, and similarly, the saltwater treatment line 203 is optimum when treating seawater. Therefore, both are the same in a rough configuration, but the detailed parts at the implementation level are different.

For example, in the same configuration as the first adsorption means 41 in the freshwater treatment line 202, instead of the first adsorbent 29, an inorganic material of alumina (Al ₂ O ₂ ) and titania (TiO ₂ ) is used as a main component. An adsorbent (removal target: Sr) can be used. Here, adsorbents mainly composed of alumina (Al ₂ O ₂ ) and titania (TiO ₂ ) -based inorganic materials are commercially available.

  FIG. 6 is an explanatory diagram in which a nuclide that can be decontaminated by the radionuclide removal system 200 of the second embodiment and a nuclide that is actually tested and confirmed to be decontaminated are described on the periodic table.

  As described above, according to the radionuclide removal system of Embodiment 2, the conditions for removing the radionuclide by separating the radioactively contaminated water into salt water and fresh water are optimized for each of the salt water and the fresh water. Therefore, the conditions can be easily set and the radionuclide can be efficiently removed.

  Furthermore, according to the radionuclide removal system of the second embodiment, the radionuclide is preliminarily removed and reused as core cooling water even before the radioactively contaminated water is separated into salt water and fresh water. It is easy and can remove a radionuclide efficiently.

40 Adsorption Unit 41 First Adsorption Means 42 Second Adsorption Means 43 Third Adsorption Means 200 Radionuclide Removal System 201 Pretreatment Line 202 Freshwater Treatment Line 203 Salt Water Treatment Line 211 Reactor 212 Radioactive Contamination Water 213 Oil Removal Device 214 Cs Removal device 215 Sr removal device 216 Salt removal device 217 Treated water temporary storage tank 218 Buffer 219 Return pipe 221 Fresh water 222 Fresh water line 225 Primary concentrated salt water storage tank 226 Evaporator 227 Evaporator treated water storage tank 228 Salt removal apparatus 229 Supplementary water supply equipment 232 Secondary concentration Saltwater storage tank 233 Concentrated saltwater 235 Seawater line

Claims (8)

A radionuclide removal system that removes multiple types of radionuclides from radioactively contaminated water,
A first adsorbing means having a first adsorbent in which a Ca low-permeability film having a Ca permeability lower than that of Sr is formed on the surface of an internal filler containing an inorganic material that adsorbs at least Ca and Sr;
A radionuclide removal system comprising: a second adsorbent having a second adsorbent containing a TiO ₂ inorganic material supporting ferrocyanated Co or ferrocyanated Fe. The Ca low-permeability membrane is
The radionuclide removal system according to claim 1, which is a Ca alginate film.   The radionuclide removal system according to claim 1 or 2, wherein the internal filler is at least one of zeolite, aluminum rimate, alumina, and silica. The radionuclide removal system further comprises:
A third adsorbing means having a third adsorbent containing a porous material;
In the third adsorbent,
The radionuclide removal system according to any one of claims 1 to 3, comprising iodine and a transuranium element adsorbent formed from iodine-supporting activated carbon and chelating agent-containing activated carbon. The radionuclide removal system further comprises:
A third adsorbing means having a third adsorbent containing a porous material;
In the third adsorbent,
Adsorbent containing inorganic carbon and alumina, adsorbent mainly composed of cesium oxide, adsorbent containing iodine and activated carbon, adsorbent containing tannin and activated carbon, adsorbent containing reduced iron and activated carbon, aluminum-based adsorbent, and transuranium The radionuclide removal system according to any one of claims 1 to 3, wherein an element removal absorbent is included. The radioactive polluted water contains salt,
The radionuclide removal system further comprises:
Equipped with a salt removal device that separates radioactive contaminated water into desalted contaminated water and concentrated salt contaminated water,
The first adsorption unit, the second adsorption unit, and the third adsorption unit are respectively
The radioactivity according to claim 4 or 5, wherein there are at least two systems: a fresh water system that adsorbs radioactive substances to the desalted contaminated water and a seawater system that adsorbs radioactive substances to the concentrated salt contaminated water. Nuclide removal system. The radionuclide removal system further comprises:
The radionuclide removal system according to claim 6, further comprising a first pre-adsorption means having the first adsorbent and a second pre-adsorption means having the second adsorbent on the upstream side of the salt removal device. A radionuclide removal method for removing multiple types of radionuclides from radioactively contaminated water,
Sr is adsorbed using the first adsorbent in which a Ca low-permeability film having a lower Ca permeability than the Sr permeability is formed on the surface of the inner filler containing an inorganic material that adsorbs at least Ca and Sr. A first adsorption step;
A second adsorbing step of adsorbing Cs using a second adsorbent containing ferrocyanated Co or ferrocyanated Fe-supported TiO ₂ inorganic material.