JP4073065B2 - Reactor containment hydrogen removal equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a hydrogen removal apparatus for a nuclear reactor containment vessel that is mainly used in a nuclear power plant and removes hydrogen generated in the nuclear reactor containment vessel at the time of an accident.
[0002]
[Prior art]
FIG. 27 is a schematic system cross-sectional view of a conventional reactor containment vessel. A reactor containment vessel 102 that houses a reactor pressure vessel 101 containing a reactor core 107 includes an upper dry well 103, a lower dry well 104, an upper dry well 103, and a vent pipe 106 that surround the reactor pressure vessel 101. And a wet well 105 having a suppression pool 105a inside. Further, a biological shielding wall 108 is installed so as to surround the reactor pressure vessel 101.
[0003]
In the unlikely event that the reactor primary cooling system piping such as the main steam pipe 109 connected to the reactor pressure vessel 101 breaks, high temperature and high pressure reactor primary coolant is discharged to the upper dry well 103 in the containment vessel 102. As a result, the pressure and temperature in the upper dry well 103 rapidly increase. The high-temperature and high-pressure coolant discharged to the upper dry well 103 is mixed with the gas in the upper dry well 103, discharged through the vent pipe 106 into the suppression pool water 105a, and cooled. Thus, much of the thermal energy released from the reactor pressure vessel 101 is absorbed in the suppression pool 105a.
[0004]
Suppression pool water 105a is injected into the reactor pressure vessel 101 by the emergency core cooling system to cool the core, but this injected water absorbs the decay heat from the core in the long term and breaks the broken pipe. It flows out from the mouth to the dry well. Therefore, at this time, the pressure / temperature in the upper dry well 103 is always higher than that of the wet well 105. Under such a long-term event, in the reactor of a light water nuclear power plant, water, which is a coolant, is radioactively decomposed to generate hydrogen gas and oxygen gas. Furthermore, when the temperature of the fuel cladding tube rises, a reaction occurs between the water vapor and the zirconium of the fuel cladding tube material (referred to as a metal-water reaction), and hydrogen gas is generated in a short time. The hydrogen gas generated in this way is discharged into the reactor containment vessel through the broken port of the broken pipe, and the hydrogen gas concentration in the reactor containment vessel 102 gradually increases. Further, since the hydrogen gas is non-condensable, the pressure in the reactor containment vessel 102 also increases.
[0005]
When no effective countermeasures can be taken against this state, the hydrogen gas concentration rises to 4 vol% and the oxygen gas concentration rises to 5 vol% or more, that is, when the combustible gas concentration exceeds the flammable limit, the gas is combustible. It becomes a state. Furthermore, excessive reaction may occur when the hydrogen gas concentration increases.
[0006]
As an effective measure against such a situation, in the case of conventional boiling water nuclear power generation facilities, the metal-water reaction can be achieved by replacing the pressure-suppressed reactor containment vessel with nitrogen gas and keeping the oxygen concentration low. This makes it possible to strictly prevent the inside of the reactor containment vessel from becoming a flammable atmosphere even with a large amount of hydrogen gas generated in a short period of time, thereby achieving inherent safety. In order to remove hydrogen gas, the combustible gas concentration control device installed outside the reactor containment vessel and having a recombiner and blower sucks the gas inside the reactor containment vessel out of the reactor containment vessel and raises the temperature. Then, hydrogen gas and oxygen gas are recombined and returned to water, and the remaining gas is cooled and then returned to the reactor containment vessel, thereby suppressing an increase in combustible gas concentration.
[0007]
Unlike the above-mentioned devices, a catalytic recombination device that promotes the recombination reaction using a hydrogen oxidation catalyst is housed in the reactor as a method for statically controlling the flammable gas concentration without requiring an external power supply. Several tens of methods have been developed in the container. The configuration of such a hydrogen removal apparatus is described in detail in, for example, Japanese Patent Laid-Open Nos. 4-34395 and 9-90092.
[0008]
[Problems to be solved by the invention]
Under the event that a large amount of hydrogen is generated by the metal-water reaction, it is difficult to remove hydrogen in a low oxygen state by the above-described conventional hydrogen treatment method by recombination of hydrogen and oxygen. Therefore, use of a hydrogen storage alloy has been proposed as a method for removing hydrogen even when oxygen concentration is low and recombination is difficult.
[0009]
Single metals such as palladium, titanium, zirconium, and rare earths react with hydrogen to occlude a large amount of hydrogen atoms between metal lattices to generate binary metal hydrides. These binary metal hydrides are It is difficult to decompose, and it is necessary to have a high temperature in order to release hydrogen, and the releasing ability is low. Therefore, by using an alloy composed of a plurality of metals having different reactions to hydrogen (referred to as a hydrogen storage alloy), hydrogen can be stored and released reversibly at a temperature close to room temperature.
[0010]
However, the weight of hydrogen stored in the hydrogen storage alloy is only a few percent of the weight of the alloy. For example, the amount of hydrogen stored in a TiFe alloy is about 1.8% of the alloy weight. Therefore, a huge amount of hydrogen storage alloy is required to cope with a large amount of hydrogen generation.
[0011]
The present invention has been made in view of the above problems, and an object of the present invention is to reliably remove hydrogen even under low oxygen conditions, and to suppress an increase in internal pressure of the reactor containment vessel due to hydrogen.
[0012]
[Means for Solving the Problems]
  In order to achieve the above object, in the present invention, a reactor containment vessel comprising a dry well surrounding a reactor pressure vessel containing a reactor core and a suppression well having a wet well for venting the atmosphere in the dry well; A hydrogen reaction means for introducing the atmosphere in the reactor containment vessel, a first pipe communicating at least one of the dry well and the wet well with the hydrogen reaction means, and the hydrogen reaction means, Second piping to connect and discharge reaction productsAnd an ammonia synthesis catalyst held inside the hydrogen reaction means, a heating means provided in the hydrogen reaction means, and a heat exchange means provided in the hydrogen reaction means, and heated by the heating means. Promote the production of ammonia by synthesizing hydrogen and nitrogen in the atmosphere in the reactor containment vessel that is heated and introduced into the hydrogen reaction means, and increase the temperature of the ammonia synthesis catalyst by the heat exchange means. Deterring,It is characterized by.
[0013]
With this configuration, hydrogen generated in the reactor containment vessel during LOCA and nitrogen present in the reactor containment vessel are introduced into the hydrogen reaction means, and the volume is reduced before and after the reaction. An increase in the internal pressure of the furnace containment vessel can be suppressed.
[0016]
Furthermore, the hydrogen separation which takes in the fluid in the first pipe and separates hydrogen and nitrogen from the fluid and transfers the separated hydrogen and nitrogen to the hydrogen reaction means and transfers components other than hydrogen and nitrogen to the second pipe. Means and nitrogen separation means.
[0017]
It is preferable that a hydrogen separation membrane and a nitrogen separation membrane are disposed in the hydrogen separation means and the nitrogen separation means so that hydrogen and nitrogen are selectively permeated. Thus, a substance unnecessary for the ammonia reaction is selected and prevented from being transferred to the hydrogen reaction means, thereby preventing the ammonia synthesis reaction from being inhibited by impurities and improving the reaction efficiency and preventing the hydrogen reaction means from being deteriorated by impurities.
[0018]
Further, according to the present invention, a reactor containment vessel comprising a dry well surrounding a reactor pressure vessel containing a core and a wet well that has a suppression pool and vents the atmosphere in the dry well, and the atmosphere in the reactor containment vessel A hydrogen reaction means for introducing hydrogen into the interior, a first pipe connecting at least one of the dry well and the wet well and the hydrogen reaction means, a second pipe connected to the hydrogen reaction means and discharging the reaction product, And a carbon compound supply means for supplying a carbon compound to the hydrogen reaction means, and synthesizes hydrogen and the carbon compound in the atmosphere in the reactor containment vessel introduced into the hydrogen reaction means through the first pipe. It is characterized by doing.
[0019]
By this structure, hydrogen generated in the reactor containment vessel at the time of LOCA and the carbon compound existing in the reactor containment vessel or the carbon compound supplied by the carbon compound supply means are introduced into the hydrogen reaction means and synthesized, An increase in the internal pressure of the containment vessel due to hydrogen can be suppressed.
[0020]
Furthermore, the fluid in the first pipe is taken in, hydrogen and carbon compounds are separated from the fluid, the separated hydrogen and carbon compounds are transferred to the hydrogen reaction means, and components other than hydrogen and carbon compounds are transferred to the second pipe. A hydrogen separation means and a carbon compound separation means.
[0021]
It is preferable that a hydrogen separation membrane and a carbon compound separation membrane are disposed in the hydrogen separation means and the carbon compound separation means so that hydrogen and the carbon compound are selectively permeated. As a result, substances unnecessary for the reaction of hydrogen and carbon compounds are selected and prevented from being transferred to the hydrogen reaction means, thereby preventing the inhibition of the synthesis reaction due to impurities and improving the reaction efficiency and preventing the deterioration of the hydrogen reaction means due to impurities. To do.
[0022]
At this time, if carbon dioxide is supplied from the carbon compound supply means to the hydrogen reaction means, since carbon dioxide is easy to generate and store among the carbon compounds, the carbon compound supply means can be easily configured. it can.
[0023]
Further, according to the present invention, a reactor containment vessel comprising a dry well surrounding a reactor pressure vessel containing a core and a wet well that has a suppression pool and vents the atmosphere in the dry well, and the atmosphere in the reactor containment vessel A hydrogen reaction means for introducing hydrogen into the interior, a first pipe connecting at least one of the dry well and the wet well and the hydrogen reaction means, a second pipe connected to the hydrogen reaction means and discharging the reaction product, A hydrogen separation means for taking in a fluid flowing through the first pipe and separating hydrogen and carbon compounds from the fluid and transferring them to the hydrogen reaction means and transferring components other than hydrogen and carbon compounds to the second pipe; Synthesizes hydrogen and carbon compounds in the atmosphere in the reactor containment vessel equipped with carbon compound separation means and introduced into the hydrogen reaction means via the first pipe And wherein the Rukoto.
[0024]
With this configuration, it is possible to suppress an increase in the internal pressure of the containment vessel due to hydrogen generated in the containment vessel at the time of LOCA, and at the same time, a necessary amount that is assumed particularly for the reaction with hydrogen in the containment vessel If there is a carbon compound, a simpler device can be realized by separating and reacting directly from the atmosphere inside the reactor containment vessel without providing a carbon compound storage facility or supply means from this storage facility. be able to.
[0025]
Further, an alcohol is generated by a reaction between the carbon compound and hydrogen in the hydrogen reaction means. Among alcohols, methanol and ethanol are easy-to-generate and chemically stable liquids, so they can be stored easily and contribute greatly to reducing the internal pressure of the reactor containment by liquefying the gas. Can do.
[0026]
The hydrogen reaction means comprises a catalyst layer comprising a carbon compound / hydrogen synthesis catalyst and introducing a carbon compound therein, and a hydrogen separation membrane that is located around the catalyst layer and permeates hydrogen. Of the atmosphere transferred from the inside, hydrogen is taken into the catalyst layer through the hydrogen permeable membrane, and this hydrogen and a carbon compound are synthesized. Thereby, the carbon compound and hydrogen can be effectively synthesized by supplying the carbon compound into the catalyst layer and introducing hydrogen from the hydrogen permeable membrane.
[0027]
In addition, an electric transfer means for transferring the atmosphere in the containment vessel to the first pipe is provided. Thereby, since the atmosphere in the reactor containment vessel can be reliably and early transferred to the hydrogen reaction means, an increase in the internal pressure of the reactor containment vessel can be suppressed earlier.
[0028]
Further, the unreacted substance discharged from the hydrogen reaction means is transferred to the first pipe and introduced again into the hydrogen reaction means. Thereby, reaction efficiency can be improved.
Further, a cooling means for cooling the fluid transferred to the reaction product accommodation means is provided, and the fluid is condensed. Thereby, especially when the reaction product is water or alcohol and exists as vapor due to high temperature, the recovery efficiency of the reaction product can be improved by liquefying the reaction product.
[0029]
The second piping is set so as to communicate the hydrogen reaction means and the reactor containment vessel. Thereby, the whole facility can be simplified by adopting a structure in which the reaction product is returned into the reactor containment vessel. Furthermore, the second pipe is set to open in the suppression pool, so that the reaction product is retained in the suppression pool water when the reactive organism is a liquid such as water or alcohol or a soluble gas such as ammonia. Therefore, the internal pressure of the reactor containment vessel can be effectively reduced with a simple structure.
[0030]
Moreover, the reaction product accommodation means for accommodating the reaction product in the hydrogen reaction means is provided, and the second pipe is set so as to communicate between the hydrogen reaction means and the reaction product accommodation means. With this configuration, by preventing the organic compound from being mixed into the reactor containment vessel, it is possible to prevent the generation of organic iodine and reduce the amount of radioactive release to the reactor containment vessel gas phase.
[0031]
Further, the reaction product storage means includes a tank for storing a liquid fluid, and introduces a gas flowing into the tank into the reactor containment vessel. When the reaction product is a liquid, the reaction product and other substances can be separated by returning only the reaction product to the reactor containment vessel after containing only the reaction product. Further, the unreacted gas can be reacted again. Also, at this time, if the second pipe is provided with a compression means so as to compress the reaction product in the hydrogen reaction means and transfer it to the reaction product accommodation means, it is accommodated especially when the reaction product is a gas. A simple structure with a relatively small volume can be realized.
[0032]
The hydrogen separation means has a hydrogen separation membrane. The method of permeating and separating hydrogen through the hydrogen separation membrane has a simpler structure and can be reliably performed as compared with the hydrogen separation method such as the PSA method or the deep cooling method.
[0033]
In the present invention, a reactor containment vessel comprising a dry well surrounding the reactor pressure vessel containing the reactor core and a wet well that has a suppression pool and vents the atmosphere inside the dry well, and at least one of the dry well and the wet well Reactor containment provided with a hydrogen reaction means for introducing an atmosphere in a reactor containment vessel provided on one side and a carbon compound supply means for supplying a carbon compound to the hydrogen reaction means. Provided is a hydrogen removal apparatus for a reactor containment vessel that synthesizes hydrogen and a carbon compound in an atmosphere in a vessel.
[0034]
With this configuration, a hydrogen reaction means is provided inside the reactor containment vessel, where the reaction between the carbon compound and hydrogen is performed, thereby suppressing an increase in the internal pressure of the reactor containment vessel and reducing the amount of the structure and the overall equipment. be able to.
[0035]
Further, in the present invention, a nuclear reactor containment vessel that includes a dry well and a suppression pool surrounding a reactor pressure vessel containing a core and a wet well that vents an atmosphere in the dry well and holds a carbon compound therein, Hydrogen reaction means provided in at least one of the dry well and the wet well for introducing the atmosphere in the reactor containment vessel into the interior, and hydrogen in the atmosphere in the reactor containment vessel introduced into the hydrogen reaction means, A carbon compound held in a reactor containment vessel is synthesized. With this configuration, for example, by realizing a natural circulation system that takes in gas using reaction heat, the amount of structures such as piping can be reduced and the entire power generation facility can be downsized.
[0036]
DETAILED DESCRIPTION OF THE INVENTION
(First embodiment)
FIG. 1 is a schematic system diagram of a hydrogen removal apparatus for a reactor containment vessel according to a first embodiment of the present invention. Since each configuration in the reactor containment vessel is substantially the same as the conventional system diagram shown in FIG. 27, only the characteristic configuration of the present embodiment will be described below.
[0037]
In the present embodiment, the ammonia synthesizing means 4 provided outside the reactor containment vessel, the piping 5a connecting the ammonia synthesizing means 4 and the dry well 1 via the isolation valve 6a, and the ammonia synthesizing means 4 And the gas phase of the wet well 2 via the isolation valve 6b, the ammonia synthesizing means 4 and the suppression pool 3 in the wet well 2 via the check valve 8, and the reaction product (main And a return pipe 7 for discharging ammonia).
[0038]
In the ammonia synthesis means 4, the chemical reaction formula
3H₂ + N₂ → 2NH_Three
An ammonia synthesis reaction represented by
[0039]
The ammonia synthesizing means 4 includes a heat exchanger (not shown), and performs cooling / heating as necessary. That is, the unreacted gas, which is mostly composed of nitrogen and hydrogen, taken from the dry well 1 and wet well 2 gas phase by opening the isolation valves 6a and 6b during LOCA is heated by a heat exchanger, Ammonia is synthesized. The temperature of the ammonia is further increased by the reaction heat generated at that time, but the reaction equilibrium is maintained by constantly cooling the ammonia synthesis reaction by being cooled by the heat exchanger. Thus, high heat efficiency can be maintained by using the heat of reaction of ammonia synthesis for raising the temperature of the unreacted gas by the heat exchanger.
[0040]
Reaction products such as ammonia and unreacted substances released from the ammonia synthesizing means 4 are introduced into the suppression pool 3 water through the return pipe 7, and the ammonia is dissolved in the suppression pool 3 water because it is soluble. Thereby, the ammonia partial pressure in the nuclear reactor containment vessel is reduced, and the increase in the containment vessel internal pressure is suppressed.
[0041]
During such an event, radioactive iodine is released into the reactor containment as a water-soluble iodide (eg CsI) and retained in the water by scrubbing in the containment spray or suppression pool 3 to produce ion I^- It reacts with water, metal ions, organic matter, and radiolysis products in water. Therefore, when the hydrogen ion concentration in the suppression pool water is high and acidic, hypoiodous acid (HOI) is generated and reacts with iodide ions, or iodide ions and dissolved oxygen in water react. The iodine molecule (I₂ ) Is generated and released into the air. That is, the equilibrium shifts to the right in the following reactions.
[0042]
IO_Three + 2I^- + 3H⁺   ← → 3HOI
HOI + I^- + H⁺   ← → I₂ + H₂ O
4I^- + O₂ + 2H⁺   ← → I₂ + H₂ O
Conversely, when the suppression pool water is alkaline, iodine is retained in the water as ions and is hardly released to the gas phase.
[0043]
In the present embodiment, the ammonia synthesized by the ammonia synthesizing means 4 is released into the suppression pool 3 water. When ammonia is dissolved in water, it becomes ammonium hydroxide and exhibits weak alkalinity. Therefore, since the release of the above-mentioned radioactive iodine to the gas phase part can be suppressed, the amount of radioactive release to the reactor containment gas phase part can be reduced.
[0044]
As a modification of the present embodiment, as shown in FIG. 2, the outlet of the return pipe 7 may be set to communicate with the wet well 2 gas phase. Or the case where the water level of the suppression pool water 3 falls for some reason is assumed. Also in this case, 3 mol of hydrogen molecules and 1 mol of nitrogen molecules react to produce 2 mol of ammonia molecules, that is, the gas volume is reduced to about 1/2 by this synthesis reaction. By returning to, the increase in the internal pressure in the storage container can be suppressed, although the extent does not reach that of the case of returning to the suppression pool 3.
[0045]
(Second Embodiment)
FIG. 3 is a schematic system diagram of a hydrogen removal apparatus for a reactor containment vessel according to a second embodiment of the present invention. The same components as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted. In the present embodiment, an ammonia recovery tank 9 containing pool water 9a is installed in the middle of the return pipe 7 in the first embodiment. A pipe 7a for connecting the ammonia synthesis means 4 and the ammonia recovery tank 9 to send reaction products and unreacted substances into the pool water 9a, and a pipe 7b for connecting the ammonia recovery tank 9 and the suppression pool 3 in the wet well 2 are provided. Provide.
[0046]
When a large amount of hydrogen generated by the metal-water reaction is generated, the atmospheric gas in the dry well 1 or the wet well 2 is sent to the ammonia synthesizing means 5, and hydrogen and nitrogen in the atmospheric gas react to generate ammonia. Ammonia, which occupies most of the generated reaction product, is retained in the tank 9 by being dissolved in the pool water in the dedicated ammonia recovery tank 9 through the pipe 7 a, and other water-insoluble substances are stored in the ammonia recovery tank 9. The phase is transferred to the storage container through the pipe 7b.
[0047]
Thereby, substantially the same effects as those of the first embodiment can be obtained, and at the same time, ammonia can be prevented from being released by storing it in a dedicated tank outside the reactor containment vessel.
[0048]
(Third embodiment)
FIG. 4 is a schematic system diagram of a hydrogen removal apparatus for a reactor containment vessel according to a third embodiment of the present invention. In the present embodiment, the blower 10 is provided on the pipe 5a or 5b that connects the dry well 1 or wet well 2 and the ammonia synthesis means 4 in the first embodiment shown in FIG. In the figure, the pipes 5a and 5b join in the middle to form the pipe 5c, and the blower 10 is provided in the middle. However, the pipe structure and the position of the blower 10 are not limited to this. Each may be communicated with the ammonia synthesis means 5 and the blower 10 may be provided in at least one of the pipes. Further, an in-house regular power source is used as a drive power source for the blower 10.
[0049]
As a result, the same effects as those of the first embodiment can be obtained, and at the same time, the blower 10 is operated during LOCA, and the atmospheric gas in the dry well 1 or the wet well 2 is forcibly sent to the ammonia synthesis means 4. Thus, hydrogen generated in the reactor containment vessel can be more reliably removed.
[0050]
In addition, as a drive power source for the blower 10 in the present embodiment, it is possible to adopt a configuration in which a dedicated emergency power source is provided instead of the use of the in-house regular power source. Thereby, hydrogen in the reactor containment vessel can be surely removed even in a situation where the external power source is lost in an emergency.
[0051]
(Fourth embodiment)
FIG. 5 is a schematic system diagram of a hydrogen removal apparatus for a reactor containment vessel according to a fourth embodiment of the present invention. In this embodiment, the ammonia synthesizing means 4 in the third embodiment uses an ammonia synthesis catalyst 11 installed in a container.
[0052]
As the ammonia synthesis catalyst 11, among the transition metals, Fe, Fe having a high ammonia synthesis effect_Three O_Four , Pt, Ru, Os or U, U_Three N_Four It is preferable to use either of them. The ammonia synthesis catalyst 11 is supported on a granular oxide carrier, and the granules are filled in a plate-like cartridge in the ammonia synthesis means container 4. The cartridge may have a cylindrical shape, and is not particularly limited to a plate shape.
[0053]
At this time, as a catalyst for ammonia synthesis, Al₂ O_Three , K₂ O, MgO, CaO, K₂ CO_Three , K, Na, Cs, Co_Three O_Four It is preferable to use any one of the above. Al₂ O_Three A catalyst substance is supported on a porous substance such as a catalyst to increase the catalyst effective surface area, thereby promoting the ammonia synthesis reaction by the catalyst. Alternatively, an alkali metal such as K, Na, or Cs is added to a catalyst such as Fe to receive electrons from the alkali metal and increase the ammonia synthesis rate.
[0054]
Alternatively, an EDA complex formed by vapor-depositing an alkali metal such as Na or K on a vapor deposition film of a transition metal phthalocyanine such as Fe, Mo, Ti, or Co, or a zeolite-transition metal (FeCl_Three , RuCl_Three , OsCl_Three ) -Potassium complexes are also effective.
[0055]
As a result, the same effects as those of the third embodiment can be obtained, and at the same time, the reaction rate of the ammonia synthesis reaction by the catalyst is further increased, so that the pressure increase in the reactor containment vessel can be more reliably and long-term. Can be suppressed.
[0056]
(Fifth embodiment)
FIG. 6 is a schematic system diagram of a hydrogen removal apparatus for a reactor containment vessel according to a fifth embodiment of the present invention. In this embodiment, a hydrogen separation means 12 and a nitrogen separation means 13 are provided in a pipe connecting the blower 10 and the ammonia synthesis means 4 in the fourth embodiment. FIG. 7 shows a schematic system diagram in which the main part of the present embodiment (the portion surrounded by the broken line in FIG. 6) is enlarged. The hydrogen separation means 12 is provided with a hydrogen separation membrane, and the nitrogen separation means 13 is provided with a nitrogen separation membrane.
[0057]
The blower 10 and the inlet side 12a of the hydrogen separation means 12 are connected by a pipe 5c. On the outlet side of the hydrogen separation means 12, there are a separated hydrogen gas outlet 12b and a gas outlet 12c from which the hydrogen gas has been removed. The hydrogen gas discharge port 12b is connected to the inlet side 4a of the ammonia synthesis means 4 by a pipe 5d. Further, the gas discharge port 12c from which the hydrogen gas has been removed is connected to the inlet side 13a of the nitrogen separation means 13 by a pipe 14a.
[0058]
Further, the outlet side of the nitrogen separation means 13 includes a separated nitrogen gas outlet 13b and a gas outlet 13c from which the nitrogen gas has been removed. The nitrogen gas discharge port 13b is connected to the inlet side 4a of the ammonia synthesizing means 4 by a pipe 14b. In the figure, the pipe 14b merges with the pipe 5d, but both pipes may communicate with the ammonia synthesis means 4 separately. On the other hand, the gas discharge port 13c from which the nitrogen gas has been removed communicates with the suppression pool 3 through a pipe 14c. In the drawing, the pipe 14c merges with the pipe 7, but both pipes may be communicated separately to the suppression pool 3.
[0059]
Examples of the hydrogen separation membrane provided in the hydrogen separation means 10 include any of organic polymer-based hydrogen separation membranes typified by polyimide and polyaramid, and metal membranes typified by metals such as palladium and vanadium or alloys thereof. Shall be used. A polymer membrane is one in which molecules pass through gaps in the polymer chain and performs separation according to the size and speed of the molecule. A metal membrane utilizes the action of the inside of the membrane being diffused by hydrogen adsorption on the membrane surface. It only permeates hydrogen. Alternatively, a composite film in which a metal film is supported using an organic polymer film as a base material may be used.
[0060]
On the other hand, the nitrogen separation membrane provided in the nitrogen separation means 13 is preferably an organic polymer membrane such as polyolefin, cellulose triacetate, polysulfone or the like.
[0061]
The atmospheric gas in the dry well 1 or the wet well 2 sucked by the blower 10 passes through the hydrogen separation means 12 and undergoes a hydrogen separation action, and the separated hydrogen is supplied to the ammonia synthesis means 4 via the pipe 5d and to the hydrogen. The gas remaining after the separation is sent to the nitrogen separation means 13 through the pipe 14a. Here, the separated nitrogen is guided to the ammonia synthesizing means 4 through the pipe 14b, and the gas remaining after the nitrogen separation is returned to the reactor containment vessel through the pipe 14c.
[0062]
Hydrogen and nitrogen are converted into ammonia by the catalyst 11 held in the ammonia synthesizing means 4 and sent to the suppression pool 3 in the reactor containment vessel through the pipe 7.
[0063]
With the above configuration, the present embodiment can obtain the same effect as the fourth embodiment, and at the same time, separates nitrogen and hydrogen from the atmosphere gas in the reactor containment vessel and performs the ammonia synthesis reaction in advance. Thus, it is possible to increase the reaction efficiency by preventing the ammonia synthesis reaction from being inhibited by impurities, and to prevent the catalyst 11 from being deteriorated.
[0064]
In addition, by using a separation membrane to separate hydrogen and nitrogen, other separation methods, for example, PSA method in which gases are passed through a plurality of towers packed with adsorbents, and mixed gas are cooled to reduce the condensation temperature. Compared with a deep cooling method in which gas separation is performed, a simple and inexpensive configuration can be achieved.
[0065]
In the present embodiment, hydrogen is first separated and then nitrogen is separated. However, the arrangement of the hydrogen separation means 12 and the nitrogen separation means 13 may be changed to reverse the separation order. Moreover, hydrogen and nitrogen separation can be achieved by a common means by disposing a hydrogen separation membrane and a nitrogen separation membrane in the same vessel.
[0066]
Further, during LOCA, it is considered that volatile compounds such as water vapor, noble gas, halogen, aerosol, and the like are generated in the dry well 1 of the reactor containment vessel. In this case, the isolation valve 6a is closed and the isolation valve 6b is opened to prevent deterioration of the functions of the separation membrane and the catalyst and to suppress the increase in the internal pressure of the storage container over a long period of time. Only the atmosphere is taken into the ammonia synthesis means 4. Alternatively, as a mechanism for removing such substances that inhibit the ammonia synthesis reaction, for example, a filter or a scrubber may be disposed upstream of the hydrogen separation means 12.
[0067]
Further, in the present embodiment, there may be considered a case in which a compression unit that compresses the hydrogen gas and nitrogen gas separated by the hydrogen separation unit 12 and the nitrogen separation unit 13 and sends the compressed gas into the ammonia synthesis unit 4 is also conceivable. FIG. 8 shows a schematic system diagram in this case. That is, the gas compressor (compressor) 15 is disposed between the junction of the pipe 5d and the pipe 14b and the ammonia synthesis means 4. The compressor 15 is preferably a centrifugal type or an axial flow type, but is not particularly limited thereto. The compressor 15 uses an on-site power source. Or when the emergency power supply of the blower 10 demonstrated in the said 3rd Embodiment is provided, you may use this together.
[0068]
The gas compressor 15 compresses the hydrogen gas and nitrogen gas and sends them to the ammonia synthesis means 4. By performing the ammonia synthesis reaction under high pressure conditions in this way, it is possible to increase the synthesis reaction rate.
[0069]
(Sixth embodiment)
FIG. 9 is a schematic system diagram of a hydrogen removal apparatus for a reactor containment vessel according to a sixth embodiment of the present invention. In the present embodiment, the ammonia synthesizing means 4 in the fifth embodiment shown in FIG. 8 is provided with a heat exchanging means and a heating means.
[0070]
That is, the nitrogen gas and hydrogen gas compressed and pressurized by the compressor 15 are supplied to the ammonia synthesizing means 4. At this time, the inside of the ammonia synthesizing means 4 is heated by the heater 16, Ammonia synthesis is performed by the retained catalyst 11. The synthesis reaction can be performed faster by raising the temperature of the gas. On the other hand, if the temperature of the catalyst 11 rises too much, the ammonia production rate decreases, so the heat exchanger 26 prevents the catalyst temperature from rising excessively. The produced ammonia and unreacted substances are returned to the suppression pool 3 water.
Thus, it is possible to increase the synthesis reaction rate by performing the ammonia synthesis reaction under high temperature conditions.
[0071]
(Seventh embodiment)
FIG. 10 is a schematic system diagram of a hydrogen removal apparatus for a reactor containment vessel according to a seventh embodiment of the present invention. In the present embodiment, the steam-water separation means 18 is arranged upstream of the hydrogen separation means 12 in the fifth embodiment shown in FIG.
[0072]
The steam / water separation means 18 is not a large-scale device such as a steam / water separator in a reactor pressure vessel, but is assumed to be composed of, for example, a metal mesh or a passage with a baffle plate. Water vapor contained in the inflowing gas undergoes a condensing action while passing through the steam separator, and is discharged as droplets.
[0073]
On the outlet side of the steam-water separation means 18, there are a gas discharge port 18b from which moisture has been removed and a water discharge port 18a from which water has been separated. The gas discharge port 18b from which moisture has been removed communicates with the inlet side of the hydrogen separation means 12, and the hydrogen gas and nitrogen gas are then separated and flow into the ammonia synthesis means 4. The water discharge port 18 b communicates with the suppression pool 3 through a pipe 19.
[0074]
With this configuration, substantially the same operational effects as those of the fifth embodiment can be obtained, and at the same time, water and nitrogen can be separated by the hydrogen separation means 12 and the nitrogen separation means 13 by removing moisture in the gas in advance. Since the performance can be improved, the ammonia synthesis reaction can be performed more reliably.
[0075]
Furthermore, according to the present embodiment, even if an event in which the water vapor partial pressure in the reactor containment vessel becomes extremely high, such as when the containment vessel spray does not operate for some reason during a severe accident, the reactor containment is performed. By liquefying the water vapor in the vessel atmosphere and returning it to the suppression pool 3 water, the increase in the internal pressure of the reactor containment vessel is suppressed, and the functional degradation due to water vapor mixing in the hydrogen separation membrane, nitrogen separation membrane, and ammonia synthesis catalyst is greatly suppressed. can do.
[0076]
(Eighth embodiment)
FIG. 11 is a schematic system diagram of a hydrogen removal apparatus for a reactor containment vessel according to an eighth embodiment of the present invention. In the present embodiment, a carbon compound / hydrogen synthesizing means 20 is arranged in place of the ammonia synthesizing means 4 in the first embodiment shown in FIG. 1, and a carbon compound is used as a raw material for reaction with hydrogen gas. The carbon compound supply means 23 to be supplied is connected.
[0077]
At the time of LOCA, the isolation valves 6a and 6b are opened, so that atmospheric gas is introduced into the container of the carbon compound / hydrogen synthesis means 20 from the dry well 1 and wet well 2 gas phase portions through the introduction port 20a. Hydrogen and carbon compounds (for example, carbon monoxide, carbon dioxide, unsaturated hydrocarbons, etc.) in the gas taken in here are produced as compounds (for example, hydrocarbons, alcohols, acids, etc.) by a synthesis reaction.
[0078]
Further, when a large amount of hydrogen is generated during LOCA, the carbon compound is fed into the container of the carbon compound / hydrogen synthesizing means 20 through the carbon compound supply means 21.
[0079]
The carbon compound supply means 23 consists of a tank or cylinder containing a carbon compound, a pipe, and a valve, and is necessary for completely reacting the generated hydrogen according to the stoichiometric ratio derived from the reaction formula according to the amount of hydrogen generated. A sufficient amount of carbon compound is supplied to the carbon compound inlet 20 c of the carbon compound / hydrogen synthesis means 20.
[0080]
For detection of generated hydrogen, a conventional hydrogen gas sensor provided in the sampling line of dry well 1 and wet well 2 is used, or storage upstream of the carbon compound / hydrogen synthesizing means of the present embodiment is used. A sampling line and a hydrogen gas sensor are provided as necessary in the vicinity of the pipe for taking in the gas in the container.
[0081]
Reactions that occur in the carbon compound / hydrogen synthesis means 20 include methanol production from carbon dioxide, C1 chemical reaction, carbon production by carbon dioxide reduction, hydrogenation reaction of unsaturated hydrocarbons, and the like. Each reaction is represented by the following chemical reaction formula.
CO₂ + 3H₂ → CH_Three OH + H₂ O (1)
CO + 2H₂ → CH_Three OH (2)
CO + 2H₂ → C + 2H₂ O
2C_n H_2n+ NH₂ → 2C_n H_3n
The discharge ports 20b of the carbon compound / hydrogen synthesis means 20 both communicate with the return pipe 7, and the reaction products and unreacted gases are introduced into the reactor containment vessel. Further, in the figure, the return pipe 7 is opened to the gas phase part of the wet well 2, but the return pipe 7 may be opened to the suppression pool 3 water as in the case of FIG. 1.
[0082]
With this configuration, it is possible to suppress an increase in the internal pressure of the reactor containment vessel by taking out a large amount of hydrogen generated during LOCA, generating a liquid such as water or alcohol such as methanol and returning it to the reactor containment vessel. . Even when the product is a carbon compound other than the liquid, the number of moles of the gaseous substance is reduced before and after the reaction. An increase in internal pressure can be suppressed.
[0083]
Further, in consideration of the fact that the gas discharged from the carbon compound / hydrogen synthesis means 20 contains radioactive substances, the reaction product is returned to the reactor containment vessel as in this embodiment. Further, it is not necessary to provide various incidental facilities such as a pressure-resistant dedicated container or blower for holding the product, and a simple structure can be obtained.
[0084]
(Ninth embodiment)
FIG. 12 is a schematic system diagram of a hydrogen removal apparatus for a reactor containment vessel according to a ninth embodiment of the present invention. In the present embodiment, the outlet 20b of the carbon compound / hydrogen synthesizing means 20 in the eighth embodiment shown in FIG. 11 is connected to the reaction product accommodating means 22 via a pipe 23.
[0085]
The reaction product storage means 22 holds the reaction product generated by the above reaction inside. This outlet side communicates with the inside of the reactor containment vessel via a return pipe 7. The storage means 22 shown in the figure assumes a chemically stable substance such as a water-soluble product as a reaction product, particularly an alcohol such as methanol or ethanol, and uses a drain tank.
[0086]
The reaction product storage means 22 is not limited to such a drain tank, and is designed in consideration of the properties of the reaction product. That is, when the reaction product is a gas, a pressure-resistant holding tank is used, and if necessary, a valve and a compressor are provided in the pipe 23 to prevent backflow. Depending on the type of gas, an adsorbent is placed in the tank for adsorption. Moreover, in the case of a soluble gas, it can also be set as the structure which stores a solvent in a tank and blows in and dissolves a gas.
[0087]
With this configuration, the same operational effects as in the eighth embodiment can be obtained, and at the same time, the reaction product is held inside the dedicated storage means, so that the organic compound and iodine molecules can be mixed inside the reactor containment vessel. Generation of organic iodine due to the reaction can be prevented, that is, mixing of organic compounds into the reactor containment vessel can be prevented.
[0088]
(Tenth embodiment)
FIG. 13 is a schematic system diagram of a hydrogen removal apparatus for a reactor containment vessel according to a tenth embodiment of the present invention. In the present embodiment, the blower 10 is provided on the pipe 5a or 5b connecting the dry well 1 or the wet well 2 and the carbon compound / hydrogen synthesis means 20 in the eighth embodiment shown in FIG. It is. In the figure, the pipes 5a and 5b join in the middle to form the pipe 5c, and the blower 10 is provided in the middle. However, the pipe structure and the position of the blower 10 are not limited to this. Each may be communicated with the carbon compound / hydrogen synthesis means 20 and the blower 10 may be provided in at least one of the pipes. Further, an in-house regular power source is used as a drive power source for the blower 10.
[0089]
As a result, the same operational effects as those of the eighth embodiment can be obtained, and at the same time, the blower 10 is operated at the time of LOCA, and the atmosphere gas in the dry well 1 or the wet well 2 is forcibly forced into the carbon compound / hydrogen synthesis means By sending it to 20, hydrogen generated in the reactor containment vessel can be removed more reliably.
[0090]
In addition, as a drive power source for the blower 10 in the present embodiment, it is possible to adopt a configuration in which a dedicated emergency power source is provided instead of the use of the in-house regular power source. Thereby, hydrogen in the reactor containment vessel can be surely removed even in a situation where the external power source is lost in an emergency.
[0091]
(Eleventh embodiment)
FIG. 14 is a schematic system diagram of a hydrogen removal apparatus for a reactor containment vessel according to an eleventh embodiment of the present invention. In the present embodiment, a catalyst 24 is disposed inside the carbon compound / hydrogen synthesis means 20 in the eighth embodiment shown in FIG. 11, for example, a fixed bed reactor, a fluidized bed reactor, or the like. One of the thin film catalytic reactors is used. In the figure, the blower 10 and the reaction product storage means 22 are used in combination.
[0092]
Hydrogen and carbon compounds (for example, carbon monoxide, carbon dioxide, unsaturated hydrocarbons, etc.) in the gas taken from the dry well 1 and wet well 2 gas phase by opening the isolation valves 6a, 6b during LOCA Is synthesized by the catalyst 24 in the carbon compound / hydrogen synthesis means 20, and a compound (for example, hydrocarbon, alcohol, acid, etc.) is generated.
[0093]
Here, the catalyst 24 chemisorbs CO and H2, and uses a metal of Group 4 to 10. For example, when Pt, Pd, or Ir is used as a catalyst, CO is non-dissociatively adsorbed and mainly alcohol such as methanol is generated. On the other hand, when Ru, Ni, Fe, Co is used as a catalyst, CO is dissociated and adsorbed to mainly generate hydrocarbons.
[0094]
FIG. 15 is a cross-sectional view schematically showing an example of the carbon compound / hydrogen synthesizing means 20 in the present embodiment. The gas flow is indicated by arrows. Among these, the broken arrow shows the flow of gas introduced from the inside of the reactor containment vessel. The carbon compound / hydrogen synthesizing means 20 includes a separation membrane 25 and a catalyst 24, and is also called a membrane reactor. A catalyst layer 24 made of the above-described catalyst is formed in the container, and a hydrogen separation membrane 25 is disposed on the outer periphery of the catalyst layer 24. The atmosphere gas in the reactor containment vessel containing hydrogen is introduced into the vessel through the introduction port 20a, and the hydrogen in the gas is guided to the catalyst layer 24 through the hydrogen separation membrane 25. For the hydrogen separation membrane 25, for example, palladium is used as a substance having excellent hydrogen permeability. Gases other than hydrogen do not permeate and are discharged out of the container through the discharge port 20b.
[0095]
On the other hand, the carbon compound that is a raw material for the reaction with hydrogen is introduced into the catalyst layer 24 from the catalyst layer inlet 20 c through the carbon compound supply means 21, and reacts with hydrogen in the catalyst layer 24. The reaction product is discharged together with unreacted hydrogen gas and carbon compound from the catalyst layer outlet 20d.
[0096]
Both the outlet 20b and the catalyst layer outlet 20d of the carbon compound / hydrogen synthesis means 20 are connected to the return pipe 7 via the pipe 23 and the reaction product storage means 22, and the reaction products and unreacted gas are supplied to the reactor. Guided into containment vessel. In addition, you may provide return piping separately with respect to the discharge port 20b and the catalyst layer discharge port 20d.
[0097]
In FIG. 15, CO is used as the carbon compound.₂ Use the chemical reaction formula
CO₂ + 3H₂ → CH_Three OH + H₂ O (1)
The case where the methanol represented by this is produced | generated is shown. However, this embodiment is not particularly limited to this reaction as long as it is a synthesis reaction of a carbon compound and hydrogen.
[0098]
CO as the carbon compound₂ As a synthesis reaction with hydrogen in the case of using, in addition to the above formula (1), one represented by the following chemical reaction formula may be considered.
CO₂ + 2H₂ → C + 2H₂ O
CO₂ + H₂ → HCOOH
CO₂ + 4H₂ → CH_Four + 2H₂ O
nCO₂ + 3nH₂ → (CH₂ )_n + 2nH₂ O
nCO₂ + (3n + 1) H₂ → C_n H_{2n + 2}+ 2nH₂ O
The first formula is a reaction for producing formic acid, and the second formula is a carbon reduction reaction.
[0099]
The third to fifth formulas are reactions that produce methane and lower hydrocarbons (propane, butane, ethylene, etc.), and these products are flammable gases and are difficult to handle. Accordingly, avoiding such a reaction, the type of catalyst and the reaction conditions are selected so as to produce a stable substance such as methanol represented by the formula (1).
[0100]
CO as raw material₂ In order to selectively produce methanol, it is preferable to use, for example, a catalyst in which palladium is supported on lanthanum oxide, or a catalyst in which palladium or silver is added to a copper-zinc-chromium-alumina catalyst.
[0101]
Chemical reaction formula with CO as raw material
CO + 2H₂ → CH_Three OH (2)
Is preferably used, a copper-zinc-alumina-based catalyst is preferably used.
[0102]
With this configuration, according to the present embodiment, substantially the same operational effects as those of the eighth embodiment can be obtained, and at the same time, the synthesis reaction between hydrogen and the carbon compound can be promoted by the catalyst, thereby ensuring faster and more reliable operation. Hydrogen in the containment vessel can be removed. In addition, by using carbon dioxide or carbon monoxide as a raw material and selectively producing a stable substance such as methanol in consideration of the catalyst and reaction conditions, the equipment required for raw material supply and reaction product retention is relatively simple. Can be.
[0103]
As the carbon compound / hydrogen synthesizing means 20 in the present embodiment, an improved version of the carbon compound / hydrogen synthesizing means 20 shown in FIG. 15 may be used. Sectional views of this improved carbon compound / hydrogen synthesizing means 20 are shown in FIGS. FIG. 16 shows the hydrogen separation membrane 25 deformed into a bowl shape. FIG. 17 shows the hydrogen separation membrane 25 arranged in a bent pipe shape. As a result, the hydrogen separation membrane surface area is increased without changing the overall volume of the carbon compound / hydrogen synthesis means 20 compared to that shown in FIG. The synthesis reaction between hydrogen and a carbon compound can be further promoted.
[0104]
(Twelfth embodiment)
FIG. 18 is a schematic system diagram of a hydrogen removal apparatus for a reactor containment vessel according to a twelfth embodiment of the present invention. In the present embodiment, the carbon compound / hydrogen synthesizing means 20 in the ninth embodiment shown in FIG. 12 is installed inside a reactor containment vessel.
[0105]
As the carbon compound / hydrogen synthesis means 20 installed in the reactor containment vessel, a system that forcibly sucks the atmospheric gas in the reactor containment vessel by a blower or a system that takes in gas by natural circulation using reaction heat However, the latter natural circulation system that can be installed with the volume of the reactor containment vessel almost as it is is desirable. The carbon compound / hydrogen synthesis means 20 is preferably installed in each of the dry well 1 and the wet well 2. Further, the reaction product discharged from the catalyst layer outlet 20 d of the carbon compound / hydrogen synthesizing means 20 is sent to the reaction product accommodating means 22 via the pipe 23.
[0106]
When a large amount of hydrogen is generated by Metal-Water reaction during LOCA, the hydrogen generated in the reactor containment atmosphere is taken into the carbon compound / hydrogen synthesis means 20 installed in the reactor containment vessel, and the carbon compound supply means It reacts with the carbon compound supplied from 23. In the figure, the carbon compound supply means 23 is installed outside the containment vessel, but it is also conceivable to install the carbon compound / hydrogen synthesis means 20 in the reactor containment vessel if the conditions of the installation location permit.
[0107]
With this configuration, it is possible to obtain substantially the same operational effects as those of the ninth embodiment, and to eliminate the amount of structures such as piping, and to make a simpler configuration capable of reducing the installation area and cost of the entire facility. it can.
[0108]
In the present embodiment, each facility is arranged as much as possible inside the reactor containment vessel so that the synthesis reaction of the ninth embodiment can be carried out inside the reactor containment vessel. With respect to the eighth embodiment, it is possible to consider such installation in the reactor containment vessel if the conditions of the installation location permit. For example, if the product of the synthesis reaction of hydrogen and a carbon compound is a stable liquid such as methanol, this embodiment is applied to the eighth embodiment, and hydrogen is completed inside the reactor containment vessel. A removal device can be realized.
[0109]
If the installation conditions permit, instead of the carbon compound supply means 23, a carbon compound as a raw material for the synthesis reaction is sealed in advance in the reactor containment vessel, and this carbon compound is added to the carbon compound / hydrogen synthesis means described above. 20 may be set to synthesize with hydrogen. Thereby, compared with the case where the carbon compound supply means 23 is provided, the reaction between hydrogen and the carbon compound is performed earlier, and the entire facility can be further simplified by eliminating the carbon compound supply means 23. it can.
[0110]
(Thirteenth embodiment)
FIG. 19 is a schematic system diagram of a hydrogen removal apparatus for a reactor containment vessel according to a thirteenth embodiment of the present invention. In the present embodiment, hydrogen separation means 12 is provided in a pipe connecting the blower 10 and the carbon compound / hydrogen synthesis means 20 in the eleventh embodiment shown in FIG. FIG. 20 shows an enlarged schematic system diagram of the main part of this embodiment (the part enclosed by the broken line in FIG. 19). The hydrogen separation means 12 is provided with the hydrogen separation membrane described in detail in the fifth embodiment.
[0111]
The blower 10 and the inlet side 12a of the hydrogen separation means 12 are connected by a pipe 5c. On the outlet side of the hydrogen separation means 12, there are a separated hydrogen gas outlet 12b and a gas outlet 12c from which the hydrogen gas has been removed. The hydrogen gas discharge port 12b is connected to the inlet side 20a of the carbon compound / hydrogen synthesizing means 20 by a pipe 5d. Further, the gas discharge port 12 c from which the hydrogen gas has been removed is connected to the pipe 14 a, and the pipe 14 a merges with the return pipe 7. These two pipes may be connected to the suppression pool 3 separately. Alternatively, it may be in contact with the wet well 2 gas phase.
[0112]
The atmospheric gas in the dry well 1 or the wet well 2 sucked by the blower 10 passes through the hydrogen separation means 12 and undergoes a hydrogen separation action, and the separated hydrogen is supplied to the carbon compound / hydrogen synthesis means 20 via the pipe 5d. The gas that is sent and remains after the hydrogen separation is returned into the reactor containment vessel through the pipe 14a and the return pipe 7.
[0113]
The carbon compound supplied from the hydrogen and carbon compound supply means 21 is synthesized with hydrogen by the catalyst 24 held in the carbon compound / hydrogen synthesis means 20 and sent to the reaction product accommodation means 22 via the pipe 23. Further, unreacted substances and some reaction products are sent to the suppression pool 3 of the reactor containment vessel through the return pipe 7.
[0114]
With the above configuration, the same effects as those of the eleventh embodiment can be obtained, and at the same time, hydrogen is separated from the atmospheric gas in the reactor containment vessel in advance and synthesized with the carbon compound, thereby synthesizing with impurities. By preventing the inhibition of the reaction, the reaction efficiency can be increased and the deterioration of the catalyst 24 can be prevented. In addition, by using a separation membrane for hydrogen separation, a simple and inexpensive structure can be obtained as compared with other separation methods.
[0115]
Further, during LOCA, it is considered that volatile compounds such as water vapor, noble gas, halogen, aerosol, and the like are generated in the dry well 1 of the reactor containment vessel. In this case, the isolation valve 6a is closed and the isolation valve 6b is opened to prevent deterioration of the functions of the separation membrane and the catalyst and to suppress the increase in the internal pressure of the storage container over a long period of time. Only the atmosphere is taken into the carbon compound / hydrogen synthesis means 20. Alternatively, as a mechanism for removing such substances that inhibit the ammonia synthesis reaction, for example, a filter or a scrubber may be disposed upstream of the hydrogen separation means 12.
[0116]
(Fourteenth embodiment)
FIG. 21 is a schematic system diagram of a hydrogen removal apparatus for a reactor containment vessel according to a fourteenth embodiment of the present invention. In the present embodiment, instead of or in addition to the carbon compound supply means in the thirteenth embodiment shown in FIG. 19, a gas is connected to a pipe connecting the hydrogen separation means 12 and the carbon compound / hydrogen synthesis means 20. A carbon compound separating means 26 for separating the carbon compound therein is provided. FIG. 22 shows an enlarged schematic system diagram of the main part of the present embodiment (the part enclosed by the broken line in FIG. 21). The carbon compound separation means 20 is provided with a carbon compound separation membrane.
[0117]
The hydrogen gas discharge port 12b of the hydrogen separation means 12 is connected to the inlet side 4a of the carbon compound / hydrogen synthesis means 20 by a pipe 5d. The gas discharge port 12c from which the hydrogen gas has been removed is connected to the inlet side 26a of the carbon compound separation means 26 via a pipe 27a.
[0118]
On the outlet side of the hydrogen separation means 12, there are a separated hydrogen gas outlet 12b and a gas outlet 12c from which the hydrogen gas has been removed. The hydrogen gas discharge port 12b is connected to the inlet side 20a of the carbon compound / hydrogen synthesizing means 20 by a pipe 5d. The gas discharge port 12c from which the hydrogen gas has been removed is connected to the inlet side 13a of the carbon compound separation means 13a by a pipe 27a. On the other hand, the outlet side of the carbon compound separation means 26 has a separated carbon compound outlet 26b and a gas outlet 26c from which the carbon compound has been removed. The carbon compound outlet 26b is connected to the catalyst layer inlet 20c of the carbon compound / hydrogen synthesizing means 20 by a pipe 27b. The gas outlet 26c from which the carbon compound has been removed is returned to the reactor containment vessel via the pipe 27c. In the figure, the pipe 27c merges with the pipe 23 and communicates with the reaction product accommodating means 22, but the outlet 26c and the unreacted substance outlet 20b of the carbon compound / hydrogen synthesis means 20 are different from the pipe 23. It may be set so that it directly communicates with the containment vessel through piping provided in the reactor.
[0119]
With the above configuration, the same effect as in the thirteenth embodiment can be obtained, and at the same time, by separating hydrogen and carbon compounds from the atmosphere gas in the reactor containment vessel in advance and performing a synthesis reaction, By preventing the inhibition of the synthesis reaction, the reaction efficiency can be increased and the deterioration of the catalyst 24 can be prevented. In addition, by using a separation membrane for separating hydrogen and carbon compounds, a simple and inexpensive structure can be obtained as compared with other separation methods.
[0120]
(15th embodiment)
FIG. 23 is a schematic system diagram of a hydrogen removal apparatus for a reactor containment vessel according to a fifteenth embodiment of the present invention. In the present embodiment, the reaction product storage means 22 and the pipe 5d in the thirteenth embodiment shown in FIG. 19 are connected by a pipe 29, and the hydrogen gas from the hydrogen separation means 12 is removed. The discharge port 12c is communicated with the inside of the reactor containment vessel via the return pipe 29. FIG. 24 shows a schematic system diagram in which the main part of the present embodiment (the portion surrounded by the broken line in FIG. 23) is enlarged.
[0121]
The hydrogen gas discharge port 12b of the hydrogen separation means 12 is connected to the inlet side 4a of the carbon compound / hydrogen synthesis means 20 by a pipe 5d. Further, the gas discharge port 12 c from which the hydrogen gas has been removed is connected to the suppression pool 3 in the reactor containment vessel via a pipe 29.
[0122]
With the above configuration, the present embodiment can obtain substantially the same effect as the above-described fourteenth embodiment, and at the same time, hydrogen is previously separated from the atmosphere gas in the reactor containment vessel and the synthesis reaction with the carbon compound is performed. The hydrogen gas separated and returned to the reactor containment vessel as it is can prevent the synthesis reaction from being inhibited by impurities, thereby improving the reaction efficiency and preventing the catalyst 24 from deteriorating. Further, the unreacted gas discharged from the carbon compound / hydrogen synthesizing means 20 is returned again to the carbon compound / hydrogen synthesizing means 20 for reaction, so that the carbon compound as a raw material for the reaction can be efficiently used.
[0123]
(Sixteenth embodiment)
FIG. 25 is a schematic system diagram of a hydrogen removal apparatus for a reactor containment vessel according to a sixteenth embodiment of the present invention. In the present embodiment, a liquid such as methanol is assumed as a reaction product obtained by the synthesis of hydrogen and a carbon compound, and the carbon compound / hydrogen synthesizing means 20 and the reaction product in the fifteenth embodiment shown in FIG. A cooling means is provided in a pipe communicating with the object accommodating means 22, and the introduced gas is cooled and condensed. The cooling means here is assumed to be a cooler or a cooling pipe, but is not particularly limited as long as it has a function of condensing steam. FIG. 26 shows a schematic system diagram in which the main part of the present embodiment (the part enclosed by the broken line in FIG. 25) is enlarged.
[0124]
That is, the discharge ports 20b and 20d of the carbon compound / hydrogen synthesis means 20 are connected to the introduction port 30a of the cooling means 30 through the pipe 31a. Of the gas introduced into the cooling means 30, the condensed and liquefied substance is sent from the liquid phase outlet 30b to the reaction product accommodation means 22 via the return pipe 31b. On the other hand, the non-condensable substance is returned to the carbon compound / hydrogen synthesizing means 20 again from the gas phase outlet 30c through the pipe 31b joined to the pipe 5d.
[0125]
With the above configuration, the present embodiment can obtain substantially the same effect as the fifteenth embodiment, and at the same time, the gas containing the reaction product discharged from the carbon compound / hydrogen synthesizing means is cooled to increase the temperature. The reaction product recovery efficiency can be further increased by liquefying and holding the reaction product present as a gas by condensation.
[0126]
【The invention's effect】
According to the present invention, by synthesizing hydrogen in the reactor containment vessel with nitrogen or a carbon compound, even when the oxygen concentration in the reactor containment vessel is low, that is, in the reactor containment vessel by Metal-Water reaction. Even in a situation where a large amount of hydrogen is generated, hydrogen can be reliably removed, and an increase in the internal pressure of the reactor containment vessel due to the generation of hydrogen can be suppressed.
[Brief description of the drawings]
FIG. 1 is a schematic system diagram of a hydrogen removal apparatus for a reactor containment vessel according to a first embodiment of the present invention.
FIG. 2 is a schematic system diagram of the hydrogen removal apparatus for the reactor containment vessel according to the first embodiment of the present invention.
FIG. 3 is a schematic system diagram of a hydrogen removal apparatus for a reactor containment vessel according to a second embodiment of the present invention.
FIG. 4 is a schematic system diagram of a hydrogen removal apparatus for a reactor containment vessel according to a third embodiment of the present invention.
FIG. 5 is a schematic system diagram of a hydrogen removal apparatus for a reactor containment vessel according to a fourth embodiment of the present invention.
FIG. 6 is a schematic system diagram of a hydrogen removal apparatus for a reactor containment vessel according to a fifth embodiment of the present invention.
FIG. 7 is a schematic system diagram showing an enlarged main part of a hydrogen removal apparatus for a reactor containment vessel according to a fifth embodiment of the present invention.
FIG. 8 is a schematic system diagram of a hydrogen removal apparatus for a reactor containment vessel according to a fifth embodiment of the present invention.
FIG. 9 is a schematic system diagram of a hydrogen removal apparatus for a reactor containment vessel according to a sixth embodiment of the present invention.
FIG. 10 is a schematic system diagram of a hydrogen removal apparatus for a reactor containment vessel according to a seventh embodiment of the present invention.
FIG. 11 is a schematic system diagram of a hydrogen removal apparatus for a containment vessel according to an eighth embodiment of the present invention.
FIG. 12 is a schematic system diagram of a hydrogen removal apparatus for a reactor containment vessel according to a ninth embodiment of the present invention.
FIG. 13 is a schematic system diagram of a hydrogen removal apparatus for a reactor containment vessel according to a tenth embodiment of the present invention.
FIG. 14 is a schematic system diagram of a hydrogen removal apparatus for a reactor containment vessel according to an eleventh embodiment of the present invention.
FIG. 15 is a schematic sectional view of a carbon compound / hydrogen synthesizing means in an eleventh embodiment of the present invention.
FIG. 16 is a schematic sectional view of a carbon compound / hydrogen synthesizing means in an eleventh embodiment of the present invention.
FIG. 17 is a schematic sectional view of a carbon compound / hydrogen synthesizing means in an eleventh embodiment of the present invention.
FIG. 18 is a schematic system diagram of a hydrogen removal apparatus for a reactor containment vessel according to a twelfth embodiment of the present invention.
FIG. 19 is a schematic system diagram of a hydrogen removal apparatus for a reactor containment vessel according to a thirteenth embodiment of the present invention.
FIG. 20 is a schematic system diagram showing, in an enlarged manner, main portions of a hydrogen removal apparatus for a reactor containment vessel according to a thirteenth embodiment of the present invention.
FIG. 21 is a schematic system diagram of a hydrogen removal apparatus for a reactor containment vessel according to a fourteenth embodiment of the present invention.
FIG. 22 is an enlarged schematic system diagram showing a main part of a hydrogen removal apparatus for a reactor containment vessel according to a fourteenth embodiment of the present invention.
FIG. 23 is a schematic system diagram of a hydrogen removal apparatus for a reactor containment vessel according to a fifteenth embodiment of the present invention.
FIG. 24 is a schematic system diagram showing, in an enlarged manner, main portions of a hydrogen removal apparatus for a reactor containment vessel according to a fifteenth embodiment of the present invention.
FIG. 25 is a schematic system diagram of a hydrogen removal apparatus for a reactor containment vessel according to a sixteenth embodiment of the present invention.
FIG. 26 is a schematic system diagram showing, in an enlarged manner, main parts of a hydrogen removal apparatus for a reactor containment vessel according to a sixteenth embodiment of the present invention.
FIG. 27 is a schematic system cross-sectional view of a conventional reactor containment vessel.
[Explanation of symbols]
1 ... Dry well, 2 ... Wet well, 3 ... Suppression pool,
4 ... ammonia synthesis means, 6a, 6b ... isolation valve,
8 ... Check valve, 9 ... Ammonia recovery tank, 10 ... Blower,
11 ... Ammonia synthesis catalyst, 12 ... Hydrogen separation means, 13 ... Nitrogen separation means,
15 ... Gas compressor, 16 ... Heater, 17 ... Heat exchanger, 18 ... Air / water separation means,
20 ... Carbon compound / hydrogen synthesis means, 21 ... Carbon compound supply means,
22 ... Reaction product storage means, 24 ... Carbon compound synthesis catalyst,
25 ... Hydrogen separation membrane, 26 ... Carbon compound separation means, 30 ... Cooling means

Claims (11)

A reactor containment vessel having a dry well and a suppression pool surrounding the reactor pressure vessel containing the reactor core and a wet well for venting the atmosphere in the dry well, and the atmosphere inside the reactor containment vessel are introduced inside hydrogen reaction means, a first pipe for communicating the at least one said hydrogen reaction unit of the dry well and the wet well, a second pipe for discharging the reaction product is connected to the hydrogen reaction unit An ammonia synthesis catalyst held inside the hydrogen reaction means, a heating means provided in the hydrogen reaction means, and a heat exchange means provided in the hydrogen reaction means, and the temperature is raised by the heating means And promoting the production of ammonia formed by synthesizing hydrogen and nitrogen in the atmosphere in the reactor containment vessel introduced into the hydrogen reaction means, and Arresting the rise in temperature of the ammonia synthesis catalyst by means, the containment vessel of the hydrogen removing apparatus according to claim. A hydrogen separation means for taking in the fluid in the first pipe and separating the hydrogen and nitrogen from the fluid and transferring the separated hydrogen and nitrogen to the hydrogen reaction means and transferring components other than hydrogen and nitrogen to the second pipe; nitrogen that it comprises separating means containment vessel of the hydrogen removing apparatus of claim 1, wherein. The hydrogen removal apparatus for a reactor containment vessel according to claim 1 or 2 , wherein an electric transfer means for transferring the atmosphere in the containment vessel to the first pipe is provided. 3. The hydrogen removal apparatus for a reactor containment vessel according to claim 1 or 2, wherein unreacted substances discharged from the hydrogen reaction means are transferred to the first pipe and introduced again into the hydrogen reaction means. The apparatus for removing hydrogen from a reactor containment vessel according to claim 1 or 2 , further comprising a cooling means for cooling the fluid transferred to the reaction product storage means, and condensing the fluid. 3. The hydrogen removal apparatus for a reactor containment vessel according to claim 1 or 2, wherein the second pipe communicates the hydrogen reaction means and the containment vessel. The hydrogen removal apparatus for a nuclear reactor containment vessel according to claim 6 , wherein the second pipe opens in the suppression pool. The reaction product containing means for containing the reaction product produced by the hydrogen reaction means is provided, and the second pipe connects the hydrogen reaction means and the reaction product containing means. Or the hydrogen removal apparatus of the reactor containment vessel of 2 description. 9. The hydrogen removal apparatus for a reactor containment vessel according to claim 8 , wherein the reaction product storage means includes a tank for storing a liquid fluid, and introduces a gas flowing into the tank into the reactor containment vessel. . The apparatus for removing hydrogen from a reactor containment vessel according to claim 9 , wherein a compression means is provided in the second pipe, and the reaction product in the hydrogen reaction means is compressed and transferred to the reaction product storage means. 3. The hydrogen removal device for a nuclear reactor containment vessel according to claim 2, wherein the hydrogen separation means has a hydrogen separation membrane.

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