JP6303238B2 - Radioactive material treatment equipment - Google Patents

Description

  The present invention relates to a radioactive material processing apparatus for processing a radioactive material such as tritium contained in highly concentrated contaminated water discharged from a nuclear reactor.

  In a nuclear power plant, tritium (tritium), which is a radioactive substance, is generated by a nuclear reaction associated with operation. Tritium is known as a very difficult substance to separate and recover from hydrogen because it has almost the same chemical properties as hydrogen.

For example, when a nuclear reactor accident occurs due to the effects of an earthquake, the treatment of highly concentrated contaminated water containing tritium may be a problem. In FIG. 4, the outline | summary of the conventional radioactive substance processing apparatus 101 which assumed such a case is shown. The radioactive substance processing apparatus 101 is an apparatus that processes radioactive substances contained in the high-concentration contaminated water C1 discharged from the reactor building 3 together with the groundwater G.
As shown in FIG. 4, the conventional radioactive substance treatment apparatus 101 includes a pretreatment apparatus 4 that pretreats highly concentrated contaminated water C <b> 1 discharged from the reactor building 3 in which the reactor 2 is stored, and a reverse osmosis membrane. The apparatus 5 (desalination apparatus), the multi-nuclide removal apparatus 6 (ALPS, Advanced Liquid Processing System), and the storage tank 8 are provided.

  In this conventional radioactive substance processing apparatus 101, the permeated water P discharged from the reverse osmosis membrane apparatus 5 is returned to the nuclear reactor 2 through the circulation line 10 to cool the nuclear reactor 2. In the radioactive substance processing apparatus 101, the concentrated water B <b> 1 discharged from the reverse osmosis membrane apparatus 5 is supplied to the multi-nuclide removal apparatus 6 to adsorb various radioactive substances other than tritium and are stored in the storage tank 8.

In the conventional radioactive substance processing apparatus 101, if the flow rate of the inflowing groundwater G is 400 m ³ / day, it is necessary to store 400 m ³ / day of tritium-containing discharged water. However, since the capacity of the storage tank 8 is limited, various techniques for concentrating and reducing tritium have been developed.
As a conventional technique for concentrating tritium, there is known a concentrating method in which electrolyzers using a plurality of solid polymer electrolyte membranes are connected in series (see Patent Document 1). In this tritium concentration method, by supplying tritium-containing discharge water to the anode side of the electrolysis apparatus, hydrogen and its hydrated water move to the cathode side, and as a result, tritium-enriched water and hydrogen gas containing tritium are obtained. Is. High concentration is enabled by connecting a plurality of electrolyzers in series.

  As another conventional technique for concentrating tritium, there is known an apparatus that combines electrolytic concentration and substitution of tritium from hydrogen gas containing tritium, and further supplies hydrogen gas to the fuel cell to recover power (patent) Reference 2).

JP 2010-6737 A JP 2001-286737 A

However, in the method described in Patent Document 1, tritium-enriched water can be produced, but the generated hydrogen gas contains tritium. Therefore, even if water is generated from this hydrogen gas, the discharge standard value (for example, 6 × 10 ⁴ becquerels / liter) cannot be satisfied.
Moreover, although it is thought that the water produced | generated with the fuel cell of the apparatus described in patent document 2 can satisfy | fill the said discharge standard value, since the tritium density | concentration of the high concentration contaminated water used as a process target is very low. There is a problem that the apparatus configuration of the isotope substitution unit becomes large.

  The present invention provides a radioactive substance treatment apparatus that makes it easy to reduce the tritium concentration of a portion of treated water to a concentration that satisfies the discharge standard value and that can reduce the volume of treated water to be stored. With the goal.

According to a first aspect of the present invention, the radioactive material processing apparatus includes a first processing unit for separating tritium-containing discharge water whose heat has been exchanged with the reactor in the reverse osmosis and concentrated salt water and a low-concentration permeate When the second processing section discharge the adsorption treatment water by adsorption treatment of radioactive substances from the concentrated salt water discharged from the first processing unit, the low-discharged from the first processing unit A third treatment unit that separates the concentration permeated water into a high-concentration treated water having a high tritium concentration and a low-concentration treated water in which the tritium concentration satisfies the discharge standard value; and the adsorption treated water treated in the second treatment unit. A circulation path for circulation to the nuclear reactor, and the low-concentration treated water discharged from the third treatment unit is discharged out of the system, and the third treatment unit includes at least an upstream treatment stage and A tritium enrichment stage having a downstream treatment stage, The concentration stage generates oxygen gas and hydrogen gas containing tritium, and electrolyzes the low-concentration permeated water so as to generate tritium-enriched water in which tritium is concentrated. A fuel cell that generates water using the oxygen gas generated by electrolysis and the hydrogen gas, and generates water in the fuel cell in the upstream processing stage. Water supplied to the electrolyzer and electrolyzed again, and water generated in the fuel cell in the downstream treatment stage is discharged as the low-concentration treated water .

  According to such a configuration, the concentrated water discharged from the first processing unit circulates as adsorbed processing water through the second processing unit, while the low-concentration permeated water discharged from the first processing unit is It is separated into high-concentration treated water and low-concentration treated water by the third treatment unit. Here, since the treated water treated in the third treatment unit becomes a low-concentration permeated water with a low tritium content, the tritium concentration of the low-concentration treated water discharged from the third treatment unit is set to the discharge standard value. It is easy to reduce the concentration to a level that satisfies the requirement. That is, the treated water to be stored can be reduced by discharging a part of the treated water in the system of the radioactive substance treatment apparatus.

Moreover, since the low concentration permeated water is introduced into the third treatment unit, the discharge amount of the high concentration treated water separated in the third treatment unit can be reduced. That is, the volume of treated water to be stored can be reduced.
Further, since the adsorption treated water discharged from the second treatment unit is used in the nuclear reactor as cooling water, treated water having a high tritium concentration is not discharged out of the system.

  According to such a configuration, the tritium is concentrated by the electrolytic device, and after the water containing tritium is generated by the reaction device, the water in the downstream processing stage is supplied to the downstream processing stage by supplying water containing tritium. The tritium concentration contained in the water discharged from the apparatus can be reduced. Therefore, if the required number of stages is determined in accordance with the tritium concentration of the treated water introduced into the third treatment unit, the tritium concentration of the waste water discharged from the final stage treatment apparatus may satisfy the discharge standard value. it can.

Further, by providing a plurality of tritium concentration stages, it is possible to obtain a concentrated liquid having a high tritium concentration and water satisfying the discharge standard value.
Further, since low concentration permeated water separated by reverse osmosis pressure is introduced into the electrolyzer, it is possible to prevent impurities such as Cl _{2 from} being mixed in gas generated by scaling or electrolysis in the electrolyzer. It is possible to prevent the reaction in the reaction apparatus from being hindered.

  In the radioactive substance processing apparatus, each of the tritium concentration stages may include a plurality of the electrolysis apparatuses and a plurality of the reaction apparatuses connected to the electrolysis apparatuses.

In the radioactive substance processing apparatus, each of the electrolysis apparatuses may include a storage tank that temporarily stores the low-concentration permeated water to be electrolyzed.
According to such a configuration, the electrode area of the electrolysis device can be made equal in each electrolysis device, and the third processing unit can be operated semi-continuously.

  ADVANTAGE OF THE INVENTION According to this invention, while making it easy to reduce the tritium density | concentration of a part of treated water to the density | concentration which satisfy | fills discharge | release reference value, the volume of treated water to be stored can be reduced.

It is a schematic block diagram of the radioactive substance processing apparatus of 1st embodiment of this invention. It is a schematic block diagram of the tritium concentration apparatus of the radioactive substance processing apparatus of 2nd embodiment of this invention. It is a schematic block diagram of the tritium concentration stage of 3rd embodiment of this invention. It is a schematic block diagram of the conventional radioactive substance processing apparatus.

(First embodiment)
Hereinafter, the radioactive substance processing apparatus 1 of 1st embodiment of this invention is demonstrated in detail with reference to drawings.
FIG. 1 is a schematic configuration diagram of a radioactive substance treatment apparatus 1 for reactor cooling water according to this embodiment. In the radioactive substance treatment apparatus 1 of the present embodiment, for example, an accident occurs in a nuclear power plant due to an earthquake or the like, and groundwater G flows into the reactor building 3, and highly concentrated contaminated water C1 containing tritium from the reactor building 3. Is a device that is supposed to be discharged.
The radioactive substance treatment apparatus 1 reduces the concentrated liquid stored by concentrating / removing the radioactive substance from the highly-concentrated contaminated water C1 that increases with the inflow of the groundwater G, and part of the treated water into the ocean. It is a device to discharge.

As shown in FIG. 1, the radioactive substance treatment apparatus 1 of the present embodiment includes a pretreatment apparatus 4 that pretreats tritium-containing effluent discharged from a reactor building 3 in which a nuclear reactor 2 is stored, and a pretreatment. Reverse osmosis membrane device 5 (desalination device, first processing unit), multinuclide removal device 6 (second processing unit), and tritium concentrating device 7 (third processing unit) provided downstream of device 4 ) And as main components.
The reactor building 3 stores a reactor 2 composed of a reactor containment vessel, a reactor pressure vessel, and the like.

For example, 400 m ³ (400 tons) of groundwater G is assumed to flow into the reactor building 3 per day.
In the reactor building 3, the reactor 2 is cooled using the treated water (adsorption treated water B <b> 2) discharged from the groundwater G and the multi-nuclide removal device 6. That is, heat exchange is performed between the nuclear reactor 2 and the groundwater G and treated water.

  The pretreatment device 4 is disposed on the downstream side of the reactor building 3 and is configured by a device for removing cesium and the like of the high-concentration contaminated water C1 discharged from the reactor building 3, an oil separation device, and the like.

The reverse osmosis membrane device 5 is disposed on the downstream side of the pretreatment device 4, and applies high pressure to the reverse osmosis membrane and applies high concentration contaminated water C2 discharged from the pretreatment device 4 by osmosis by permeation water (low concentration). This is a device for separating permeate P) and concentrated water B1 (concentrated salt water). The desalination rate of the reverse osmosis membrane device 5 of the present embodiment is 50%.
The reverse osmosis membrane device 5 includes a permeate line 11 for discharging the low-concentration permeate water P that has passed through the reverse osmosis membrane of the reverse osmosis membrane device 5, a concentrated water line 12 for discharging the concentrated water B1, have.

The multi-nuclide removal device 6 is disposed on the downstream side of the concentrated water line 12 of the reverse osmosis membrane device 5. That is, the concentrated water B1 is introduced from the reverse osmosis membrane device 5 to the multi-nuclide removal device 6.
The multi-nuclide removal device 6 includes a pretreatment facility including an iron coprecipitation treatment facility and a carbonate precipitation treatment facility, and an adsorption tower that adsorbs radioactive substances using titanate or the like as an adsorbent. It is a facility that removes various substances such as radioactive substances dissolved in the concentrated water B1 separated from the water. As the multi-nuclide removal apparatus 6, there is known an ALPS (Advanced Liquid Processing System) that can remove 62 kinds of radioactive substances except tritium (reduction to a reference value or less).
The multi-nuclide removal device 6 and the reactor building 3 are connected by a circulation line 10 (circulation path). That is, the concentrated water B1 discharged from the reverse osmosis membrane device 5 is subjected to a radioactive substance removal process in the multi-nuclide removal device 6 and then introduced into the reactor building 3 to be used as reactor cooling water. .

The tritium concentrator 7 is disposed on the downstream side of the permeate line 11 of the reverse osmosis membrane device 5. That is, the low concentration permeated water P separated by the reverse osmosis membrane device 5 is introduced into the tritium concentration device 7. The tritium concentrator 7 is configured to use low-concentration permeated water P, a small amount of concentrated liquid (high-concentration treated water T) having a high tritium concentration, and water (low-concentration treatment) satisfying the discharge standard value of 6 × 10 ⁴ becquerels / liter. This is a device for separating water W).

As the tritium concentration device 7, for example, an evaporation concentration device can be used. For example, when using an evaporative concentration apparatus, a plurality of evaporative concentration apparatuses may be installed in multiple stages in order to satisfy the above specifications. Although no limitation on the number of the plurality of evaporative concentration apparatus, the tritium concentration device 7, and the low concentration treatment water W that satisfies the effluent standard value of 340m ³ / day low concentration permeate P of 400 meters ³ / day, 60 m ³ It is preferable that the number of stages is separable into high-concentration treated water T having a high tritium concentration per day.

Next, the operation of the radioactive substance processing apparatus 1 of the above embodiment will be described.
For example, 400 m ³ / day of groundwater G flows into the reactor building 3. The reactor 2 is circulated and cooled by adsorption treated water B2 that functions as reactor cooling water.
The high-concentration contaminated water C1 composed of the groundwater G and the adsorption treated water B2 used for cooling the reactor 2 is introduced into the pretreatment device 4 to remove cesium and the like. The high concentration contaminated water C2 discharged from the pretreatment device 4 is introduced into the reverse osmosis membrane device 5 and separated into the low concentration permeated water P and the concentrated water B1. Since the desalination rate of the reverse osmosis membrane device 5 is 50%, when 800 m ³ / day of high-concentration contaminated water C2 is introduced into the reverse osmosis membrane device 5, 400 m ³ / day of concentrated water B1 and 400 m ³ / Separated into low concentration permeated water P of 3 days.
The low-concentration permeated water P is treated water with reduced tritium concentration. The concentrated water B1 is treated water containing tritium and other radioactive substances.

The concentrated water B1 separated by the reverse osmosis membrane device 5 is circulated and introduced into the reactor building 3 via the multi-nuclide removal device 6 and used as reactor cooling water.
The low concentration permeated water P separated by the reverse osmosis membrane device 5 is introduced into the tritium concentration device 7. The low concentration permeated water P (400 m ³ / day) introduced into the tritium concentrator 7 is a high concentration treated water T (60 m ³ / day) having a high tritium concentration and a discharge standard value of 6 × 10 ⁴ becquerels / liter. Is separated into low-concentration treated water W (340 m ³ / day) that satisfies the following conditions.
The high concentration treated water T discharged from the tritium concentrating device 7 is stored in the storage tank 8.
The low-concentration treated water W that satisfies the discharge standard value discharged from the tritium concentrator 7 is discharged, for example, into the ocean.

According to the above embodiment, the concentrated water B1 discharged from the reverse osmosis membrane device 5 circulates as reactor cooling water through the multi-nuclide removal device 6, while the low concentration permeated water discharged from the reverse osmosis membrane device 5. P is separated into high-concentration treated water T and low-concentration treated water W by the tritium concentrating device 7.
Here, since the treated water treated by the tritium concentrating device 7 becomes the low-concentrated permeated water P having a low tritium content, the tritium concentration of the low-concentrated treated water W discharged from the tritium concentrating device 7 is set as the discharge reference value. It is easy to reduce the concentration to a level that satisfies the requirement. That is, the treated water to be stored can be reduced by discharging a part of the treated water in the system of the radioactive substance treatment apparatus 1.

Moreover, since the low concentration permeated water P is introduced into the tritium concentrating device 7, the discharge amount of the high concentration treated water T separated by the tritium concentrating device 7 can be reduced. That is, the volume of treated water to be stored can be reduced.
Further, since the adsorption treated water B2 discharged from the multi-nuclide removing device 6 is used in the nuclear reactor 2 as cooling water, treated water having a high tritium concentration is not discharged outside the system.

(Second embodiment)
Hereinafter, the radioactive substance processing apparatus of 2nd embodiment of this invention is demonstrated based on drawing. In the present embodiment, differences from the first embodiment described above will be mainly described, and description of similar parts will be omitted.
As shown in FIG. 2, the tritium concentrating device 7 provided in the radioactive substance processing apparatus of the present embodiment includes a plurality of electrolyzers 14 and a plurality of fuel cells 15. Specifically, the tritium concentrating device 7 of this embodiment includes ten electrolyzers 14 (only three are shown in FIG. 2) and ten fuel cells 15 (only three are shown in FIG. 2). This is an apparatus in which three stages of tritium concentration stages 16 are arranged.

First, components constituting the tritium concentration stage 16 will be described.
The electrolysis device 14 is a device that electrolyzes the permeated water P discharged from the reverse osmosis membrane device 5 using an ion exchange membrane method, and has an electrolysis tank 17 and a DC power supply device (not shown). ing. The electrolyzer 14 generates oxygen gas and hydrogen gas containing tritium by electrolyzing the permeated water P, and also generates tritium concentrated water.

The electrolytic cell 17 has a membrane-like ion exchange membrane 20 (solid polymer electrolyte membrane) provided at the center and a disc-like shape having a smaller diameter than the ion exchange membrane 20 disposed opposite to both surfaces of the ion exchange membrane 20. An anode 18 and a cathode 19. As the ion exchange membrane 20, Nafion 117 (registered trademark, manufactured by DuPont) is preferably used.
The ion exchange membrane 20 is a membrane made of an ion exchange resin, and is a membrane having the property of blocking the passage of ions with different signs and allowing only ions with the same signs to pass.

The electrolytic cell 17 is partitioned into an anode chamber 29 and a cathode chamber 30 by the ion exchange membrane 20. The anode 18 and the cathode 19 are in close contact with the ion exchange membrane 20 in the anode chamber 29 and the cathode chamber 30, respectively.
The electrolytic cell 17 has an inlet 21 for introducing permeate P into the anode chamber 29 of the electrolytic cell 17 and an outlet 22 for discharging tritium-enriched water from the inside of the electrolytic cell 17. Furthermore, the electrolytic cell 17 has an oxygen line 23 that discharges oxygen gas and a hydrogen line 24 that discharges hydrogen gas.

  The fuel cell 15 is a predetermined fuel cell in which plate-shaped cells are stacked, and is a battery that generates electricity using oxygen gas and hydrogen gas supplied from the electrolysis device 14. Specifically, the fuel cell 15 of the present embodiment is connected to the oxygen line 23 and the hydrogen line 24 of the electrolyzer 14, and discharges water generated from power generation (hereinafter referred to as battery drainage W). A drain line 25 is provided.

The tritium concentration stage 16 connects the outlet 22 of the upstream electrolyzer 14 and the inlet 21 of the downstream electrolyzer 14 to each other, and connects the fuel cell to the oxygen line 23 and the hydrogen line 24 of each electrolyzer 14. 15 is connected.
The tritium enrichment stage 16 has a junction line 26 that connects the cell drain lines 25 of the fuel cells 15 and sends the cell drain W discharged from the fuel cell 15 to the tritium enrichment stage 16 on the downstream side. .

Among the merging lines 26, the merging line 26 that discharges the battery drainage W of the final tritium concentration stage 16c can be discharged into the ocean, for example.
The outlet 22 of the electrolyzer 14-10 on the most downstream side of each tritium concentration stage 16 is connected to a concentrate line 27 for recovering the concentrate (high-concentration treated water T).

The configuration of the tritium concentrating device 7 (the number of installed tritium concentrating stages 16, electrolyzers 14, and fuel cells 15) is appropriately determined according to the flow rate of the low-concentration permeated water P to be supplied, the tritium concentration, and the required discharge reference value. The The tritium concentrating device 7 of the present embodiment is configured to reduce the tritium concentration of the low-concentration permeated water P of 400 m ³ / day, 5.0 × 10 ⁶ becquerels / liter to the release standard value of 6.0 × 10 ⁶ becquerels / liter. Designed to have reduced throughput.

The mass balance per cell of the electrolyzer 14 is described in the literature (Masaaki Saito et al., Comparison of tritium concentration on the cathode side and anode side in solid polymer electrolysis, Electrochemistry and industrial physical chemistry, 370-372, Vol. 77, No. 5, 2009). That is, 2.91 g of accompanying water was leached from the anode chamber 29 to the cathode chamber 30 during decomposition of 1 g of water. From the experimental data, the tritium partition coefficient (the amount of tritium transferred to the hydrogen gas side / the amount of tritium in the feed water) was set to 0.0209.
In addition, the electrode area of each electrolyzer 14 is an area corresponding to the flow rate of the supplied treated water (low concentration permeated water P), the tritium concentration, and the like. That is, in each tritium concentration stage 16, the electrode area of the electrolyzer 14 is set to be gradually reduced.

Next, the operation of the tritium concentrator 7 of this embodiment will be described.
The low-concentration permeated water P discharged from the reverse osmosis membrane device 5 (see FIG. 1) is introduced into the anode chamber 29 of the electrolysis device 14-1 of the most upstream tritium concentration stage 16a. When electric charges are supplied to the anode 18 and the cathode 19 by the DC power supply device, oxygen gas is generated in the vicinity of the anode 18 and hydrogen ions are generated.

  Further, hydrogen ions accompanied with accompanying water pass through the ion exchange membrane 20 and are leached from the anode chamber 29 toward the cathode chamber 30, and hydrogen gas is generated in the vicinity of the cathode 19. As the electrolysis progresses, the accompanying water enriched with tritium is gradually stored in the cathode chamber 30 as stored water. Next, this stored water is introduced into the anode chamber 29 of the electrolytic cell 17 of the electrolyzer 14-2 on the downstream side. By repeating this, the tritium in the low-concentration permeated water P is concentrated and discharged from the most downstream electrolyzer 14-10.

  Oxygen gas and hydrogen gas generated in each electrolyzer 14 are supplied to the fuel cell 15 and used for power generation. Here, tritium is contained in the hydrogen gas. That is, tritium is contained in the battery waste water W generated by oxygen gas and hydrogen gas.

The battery waste water W containing tritium generated by power generation is introduced into the tritium concentration stage 16b on the downstream side via the battery drain line 25 and the merge line 26, and the tritium concentration stage 16a is the same as the tritium concentration stage 16a in the first stage. Is concentrated and introduced into the concentrate line 27, and battery drainage W is introduced into the tritium concentration stage 16c on the downstream side (final stage).
Also in the final stage tritium concentration stage 16c, the battery waste water W containing tritium is concentrated and the battery waste water W with reduced tritium is discharged. The battery waste water W discharged from the final stage tritium concentration stage 16c satisfies the tritium concentration of 6.0 × 10 ⁶ becquerels / liter, which is the discharge standard value.

According to the above-described embodiment, tritium is concentrated by the electrolyzer 14, and after the battery drain W containing tritium is generated by the fuel cell 15, the battery drain W is supplied to the downstream tritium concentration stage 16, thereby downstream The tritium concentration contained in the battery drainage W discharged from the fuel cell 15 of the side tritium concentration stage 16 can be reduced.
Therefore, if the required number of tritium concentration stages is determined according to the tritium concentration of the treated water introduced into the tritium concentrator 7, the tritium concentration of the battery waste water W discharged from the final stage fuel cell 15 is set as the discharge standard value. Can be satisfied.

Further, by providing a plurality of tritium concentration stages 16, a concentrated liquid (high concentration treated water T) having a high tritium concentration can be obtained.
Moreover, since the low concentration permeated water P separated by the reverse osmosis membrane device 5 is introduced into the electrolyzer 14, impurities such as Cl ₂ are mixed in the gas generated by scaling or electrolysis in the electrolyzer 14. Can be suppressed. Thereby, the reaction in the fuel cell 15 is not hindered.

  In the above embodiment, the fuel cell 15 is employed as a device for reacting the oxygen gas and hydrogen gas discharged from the electrolysis device 14. However, the present invention is not limited to this as long as water can be generated from the oxygen gas and hydrogen gas. For example, a boiler power generation device can be adopted as a reaction device for reacting oxygen gas and hydrogen gas.

(Third embodiment)
Hereinafter, the radioactive substance processing apparatus of 3rd embodiment of this invention is demonstrated based on drawing. In the present embodiment, differences from the second embodiment described above will be mainly described, and description of similar parts will be omitted.
As shown in FIG. 3, a storage tank 31 for temporarily storing low-concentration permeated water P to be electrolyzed is provided on the upstream side of the electrolyzer 14 of the tritium concentration stage 16 of the present embodiment.

  According to the above embodiment, the electrode area of the electrolyzer 14 can be made equal in each electrolyzer 14, and the tritium concentrator 7 can be operated semi-continuously. That is, the tritium concentrating device 7 can be operated in a batch operation.

  Although the embodiments of the present invention have been described in detail with reference to the drawings, the configurations and combinations of the embodiments in the embodiments are examples, and the addition and omission of configurations are within the scope not departing from the gist of the present invention. , Substitutions, and other changes are possible. Further, the present invention is not limited by the embodiments, and is limited only by the scope of the claims.

DESCRIPTION OF SYMBOLS 1 Radioactive material processing apparatus 2 Reactor 3 Reactor building 4 Pretreatment apparatus 5 Reverse osmosis membrane apparatus (1st process part)
6 Multi-nuclide removal equipment (second processing unit)
7 Tritium concentrator (third processing unit)
8 Storage tank 10 Circulation line (circulation path)
11 Permeated Water Line 12 Concentrated Water Line 14 Electrolyzer 15 Fuel Cell (Reactor)
16 Tritium Concentration Stage 17 Electrolyzer 18 Anode 19 Cathode 20 Ion Exchange Membrane 21 Inlet 22 Outlet 23 Oxygen Line 24 Hydrogen Line 25 Battery Drain Line 26 Merge Line 27 Concentrate Line 29 Anode Chamber 30 Cathode Chamber 31 Reservoir B1 Concentrated Water B2 Adsorbed treated water C1, C2 High concentration contaminated water (tritium-containing discharged water)
G Groundwater P Low concentration permeated water T High concentration treated water W Low concentration treated water, battery drainage

Claims (3)

A first processing unit which is separated into a concentrated salt water and low-concentration permeate by heat exchanged tritium containing water discharged reverse osmosis in a nuclear reactor,
A second processing section you discharge the adsorption treatment water by adsorption treatment of radioactive substances from the concentrated salt water discharged from the first processing unit,
A third treatment unit that separates the low-concentration permeated water discharged from the first treatment unit into a high-concentration treatment water having a high tritium concentration and a low-concentration treatment water in which the tritium concentration satisfies the discharge standard value ;
A circulation path for circulating the adsorption treated water treated in the second treatment section to the nuclear reactor,
The low-concentration treated water discharged from the third treatment unit is discharged out of the system,
The third processing unit comprises a plurality of tritium concentration stages having at least an upstream processing stage and a downstream processing stage,
The tritium concentration stage generates oxygen gas and hydrogen gas containing tritium, and electrolyzes the low-concentration permeated water so as to generate tritium-enriched water in which tritium is concentrated, and the electrolyzer A fuel cell that generates water while generating electricity with the oxygen gas and the hydrogen gas generated by electrolysis at
Water generated in the fuel cell in the upstream processing stage is supplied to the electrolyzer in the downstream processing stage and electrolyzed again;
Water generated in the fuel cell in the downstream treatment stage is discharged as the low-concentration treated water . 2. The radioactive substance processing apparatus according to claim 1 , wherein each of the tritium concentration stages includes a plurality of the electrolyzers and a plurality of the reaction apparatuses connected to the electrolyzers. The radioactive substance processing apparatus according to claim 2 , wherein each of the electrolysis apparatuses has a storage tank that temporarily stores the low-concentration permeated water to be electrolyzed.

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