JP7304470B2 - Organic iodine collection device and organic iodine collection method - Google Patents

Description

TECHNICAL FIELD The present invention relates to an organic iodine collection device and an organic iodine collection method for collecting radioactive organic iodine emitted from a nuclear reactor and organic iodine contained in fluid such as steam.

A filter vent device is installed in a nuclear reactor facility in order to prevent radioactive materials released from the nuclear reactor from leaking into the environment. If the reactor core is damaged due to a nuclear reactor accident or the pressure inside the containment vessel rises abnormally, the containment vessel will be damaged and lead to a large-scale leak, so the steam inside the containment vessel will be vented in advance. When the high-temperature, high-pressure steam is released from the reactor into the containment vessel, it is passed through a filter vent system to remove major radioactive materials before being released into the atmosphere.

Rare gases, aerosols, inorganic iodine, organic iodine, and the like are examples of radioactive materials generated at the time of a nuclear reactor accident. With the filter vent device, these radioactive substances, excluding noble gases, are trapped in the container and prevented from being released to the environment. Generally, a filter vent device holds scrubbing water acting as a wet filter in a container and incorporates a metal filter which is a dry filter, as described in Patent Document 1.

The scrubbing water is an aqueous solution in which sodium thiosulfate, sodium hydroxide, etc. are dissolved, and the vented steam is released into the scrubbing water. Inorganic iodine (elemental iodine) ionized by reaction with sodium thiosulfate and hydrophilic aerosol are collected by dissolving in scrubbing water. Also, the aerosol released into the gas phase adheres to and collides with the metal filter and is collected. Organic iodine is collected by dry filters such as silver zeolite and activated carbon, as described in Patent Document 2.

Japanese Patent Publication No. 2015-522161 JP-A-7-209488

Organic iodine released from nuclear reactors, including methyl iodide, is poorly soluble in water, and even if it is introduced into the pool water or scrubbing water of the pressure suppression chamber during venting, it is not sufficiently captured. In addition, organic iodine such as methyl iodide may be newly generated by the reaction of elemental iodine during the exhaust process from the nuclear reactor. For these reasons, organic iodine is a radioactive substance that is difficult to prevent from leaking, so there is a need for a filter vent device capable of efficiently collecting organic iodine.

As a trapping material for trapping organic iodine, silver zeolite and activated carbon are known (see Patent Document 2). However, since the collection efficiency of these collection materials decreases when moisture adheres thereto, a mechanism for removing moisture is required as in Patent Document 2, which complicates the structure of the filter vent device. In addition, since a large amount of these trapping materials are required, a special device design and a complicated device structure are required as in Patent Document 2, and the cost of the trapping materials themselves increases.

Accordingly, an object of the present invention is to provide an organic iodine collecting apparatus and an organic iodine collecting method capable of efficiently collecting organic iodine in a nuclear reactor containment vessel.

In order to solve the above problems, an organic iodine collection device according to the present invention is an organic iodine collection device for collecting organic iodine in a nuclear reactor containment vessel, comprising a nonvolatile organic iodine capable of decomposing organic iodine a liquid container containing a non-volatile liquid; and an introduction pipe for introducing a fluid containing organic iodine in a nuclear reactor containment vessel into the non-volatile liquid. is heated in the reactor containment vessel prior to contact with the organic iodine, or circulated into the reactor containment vessel prior to contact with the organic iodine by the heat of After being heated or by the heat of reaction between the fluid in the reactor containment vessel and reactants reacting with the material released into the reactor containment vessel prior to contact with the organic iodine. Then, the fluid is passed through to decompose the organic iodine.

Further, an organic iodine collection method according to the present invention is a method for collecting organic iodine in a nuclear reactor containment vessel, wherein a nonvolatile liquid capable of decomposing organic iodine is heat within the reactor containment prior to contact with the organic iodine; or into the reactor containment prior to contact with the organic iodine; prior to contact with the organic iodine by circulating and heating or by the heat of reaction between the fluid in the reactor containment vessel and the reactant reacting with the material released into the reactor containment vessel; After heating, the fluid containing organic iodine in the containment vessel is passed through the heated nonvolatile liquid to decompose the organic iodine into the nonvolatile liquid and collect the organic iodine.

ADVANTAGE OF THE INVENTION According to this invention, the organic iodine collection apparatus and organic iodine collection method which can collect efficiently the organic iodine in a nuclear reactor containment vessel can be provided.

BRIEF DESCRIPTION OF THE DRAWINGS It is sectional drawing which shows typically an example of the organic iodine collection apparatus which concerns on this invention. BRIEF DESCRIPTION OF THE DRAWINGS It is sectional drawing which shows typically an example of the organic iodine collection apparatus which concerns on this invention. BRIEF DESCRIPTION OF THE DRAWINGS It is sectional drawing which shows typically an example of the organic iodine collection apparatus which concerns on this invention. BRIEF DESCRIPTION OF THE DRAWINGS It is sectional drawing which shows typically an example of the organic iodine collection apparatus which concerns on this invention. BRIEF DESCRIPTION OF THE DRAWINGS It is sectional drawing which shows typically an example of the organic iodine collection apparatus which concerns on this invention. BRIEF DESCRIPTION OF THE DRAWINGS It is sectional drawing which shows typically an example of the organic iodine collection apparatus which concerns on this invention. BRIEF DESCRIPTION OF THE DRAWINGS It is sectional drawing which shows typically an example of the organic iodine collection apparatus which concerns on this invention. BRIEF DESCRIPTION OF THE DRAWINGS It is sectional drawing which shows typically an example of the organic iodine collection apparatus which concerns on this invention. BRIEF DESCRIPTION OF THE DRAWINGS It is sectional drawing which shows typically an example of the organic iodine collection apparatus which concerns on this invention. BRIEF DESCRIPTION OF THE DRAWINGS It is sectional drawing which shows typically an example of the organic iodine collection apparatus which concerns on this invention. BRIEF DESCRIPTION OF THE DRAWINGS It is sectional drawing which shows typically an example of the organic iodine collection apparatus which concerns on this invention. BRIEF DESCRIPTION OF THE DRAWINGS It is sectional drawing which shows typically an example of the organic iodine collection apparatus which concerns on this invention.

Hereinafter, an organic iodine trapping device and an organic iodine trapping method according to an embodiment of the present invention will be described with reference to the drawings. It should be noted that, in each of the following drawings, configurations having the same main function are denoted by the same reference numerals, and overlapping descriptions are omitted.

The organic iodine collection device and the organic iodine collection method according to the present embodiment are a gas (fluid) containing organic iodine released into the reactor containment vessel during filter venting performed in the event of a nuclear reactor accident. ) is passed through a non-volatile liquid that works as a wet filter to decompose the organic iodine in the gas into the non-volatile liquid and collect it. In this device and method, radioactive organic iodine is decomposed into ions and collected in a container under isolation.

As the non-volatile liquid, a non-volatile liquid that does not substantially volatilize at a temperature lower than about 160° C. is used. At the time of a nuclear reactor accident, venting of high-temperature steam of around 160°C is assumed. If the liquid acting as a wet filter is non-volatile, volatilization of the liquid itself can be avoided even if high-temperature, high-pressure gas is introduced during venting. More preferably, the nonvolatile liquid is one that does not substantially volatilize at a temperature lower than 200°C.

Further, as the non-volatile liquid, a liquid exhibiting an action of decomposing organic iodine is used. If the liquid acting as a wet filter is capable of decomposing the organic iodine, it can dissociate the radioactive iodine ions from the radioactive organic iodine. Since iodine ions are more stable in the liquid phase than organic iodine, the radioactive organic iodine can be trapped in the liquid phase and reliably prevented from leaking into the environment.

As the nonvolatile liquid, for example, an ionic liquid, a surfactant solution, a mixed solution thereof, or the like can be used. Particularly preferred non-volatile liquids are ionic liquids. The ionic liquid provides nonvolatility that does not substantially volatilize at 160° C. or less, heat resistance that can withstand high temperatures around 160° C., high radiation resistance, high chemical stability, high electrical stability, and the like. In addition, it is possible to easily control the compatibility between liquids and control the specific gravity of liquids based on a wide variety of combinations of ions.

Examples of cations constituting ionic liquids include organic cations such as phosphonium, ammonium, sulfonium, pyrrolidinium, and piperidinium.

The cation constituting the ionic liquid may be an organic cation having a linear carbon chain, an organic cation having a cyclic carbon chain, or the like, and an organic cation having a carbon chain with 2 or more carbon atoms. is preferred. With such a bulky organic cation, the reaction rate between the organic iodine and the cation increases, so the organic iodine can be collected with high collection efficiency.

Examples of anions constituting the ionic liquid include inorganic anions such as halogen, tetrafluoroborate and hexafluorophosphate, and organic anions such as acetate, sulfonate and imidate. Halogen includes fluoride ion, chloride ion, bromide ion, iodide ion and the like.

As the anions constituting the ionic liquid, highly nucleophilic ions are preferable because they have a strong action of decomposing organic iodine. As the anion, halogen, imidate, or tetrafluoro is preferred because of its high nucleophilicity, its resistance to thermal decomposition and hydrolysis, and its difficulty in changing the pH of the scrubbing water when it is injected into the filter vent container. Borate is more preferred.

As the halogen constituting the ionic liquid, chloride ion is preferable in terms of safety and high nucleophilicity. Non-radioactive iodide ions are preferred from the viewpoint of avoiding leakage of radioactive substances due to volatilization of elemental iodine. Even if the radioactive organic iodine is decomposed and captured once, the radioactive iodine ions captured in the liquid phase may react with the iodine ions in the liquid phase to generate volatile elemental iodine. There is If the halogen constituting the ionic liquid is a non-radioactive iodide ion, the probability of generating elemental iodine can be reduced.

Specific examples of non-volatile liquids include trihexyl(tetradecyl)phosphonium chloride, trihexyl(tetradecyl)phosphonium dicyanamide, and the like. As the nonvolatile liquid, trihexyl(tetradecyl)phosphonium chloride is particularly preferable because of its high ability to decompose organic iodine.

Usually, the decomposition reaction of organic iodine is rapidly initiated by attack of bound iodine when a gas containing organic iodine is introduced into a highly nucleophilic liquid. However, conventional wet filters are kept at room temperature before a nuclear reactor accident. During a nuclear reactor accident, the high-temperature, high-pressure gas in the containment vessel is vented and passed through the wet filter, which may remain cold at the beginning of the vent.

Therefore, in the organic iodine collecting device and the organic iodine collecting method according to the present embodiment, the organic iodine is decomposed after heating the nonvolatile liquid capable of decomposing the organic iodine. The non-volatile liquid can be heated to any temperature above ambient temperature using the heat within the reactor containment vessel, the heat of reaction of materials within the reactor containment vessel, or both. The non-volatile liquid may be heated before introducing the gas containing organic iodine into the non-volatile liquid, or may be heated while introducing the gas containing organic iodine into the non-volatile liquid.

FIG. 1 is a cross-sectional view schematically showing an example of an organic iodine collecting device according to the present invention.
In Figure 1, a liquid container containing a non-volatile liquid that can decompose organic iodine is installed in a dry well in the reactor containment vessel, and the non-volatile liquid is heated by the heat in the reactor containment vessel. Figure 1 shows the collection device used.

As shown in FIG. 1, a collection device 100 according to the present embodiment includes a reactor containment vessel 10 containing a reactor pressure vessel, and steam (gas) in the reactor containment vessel 10 to remove radioactive substances. and a filter vent device 20 that releases into the environment. The collection device 100 includes a liquid container 1, upstream vent pipes (2a, 2b), a pressure release valve 4, an isolation valve 5, a filter vent container 6, a metal filter 7, and a downstream vent pipe 8. , and an exhaust stack 9 .

The reactor containment vessel 10 has a dry well 11 in which a reactor pressure vessel is housed and a wet well 12 in which a pressure suppression pool is formed. Pool water is stored in the wet well 12 . Steam released into the drywell 11 and steam escaped from the main steam system under overpressure can flow into the wetwell 12 via a vent pipe (not shown). The pressure in the containment vessel 10 is suppressed by condensing the high-temperature, high-pressure gas with the pool water.

In the collection device 100 , upstream vent pipes ( 2 a, 2 b ) for venting the gas inside the containment vessel 10 are connected to the drywell 11 . A liquid container 1 is connected in the middle of the upstream vent pipes (2a, 2b). A liquid container 1 is installed in a dry well 11 of a nuclear reactor containment vessel 10 .

The liquid container 1 is a closed container containing a nonvolatile liquid L1 capable of decomposing organic iodine. A liquid container 1 is provided with a non-volatile liquid L1 that serves as a wet filter in case of a nuclear reactor accident. The shape and capacity of the liquid container 1 and the amount of the nonvolatile liquid L1 are not particularly limited. The liquid container 1 may be provided with fins, tubes, or the like for heat exchange in order to efficiently heat the nonvolatile liquid L1.

An inlet pipe 2a constituting an upstream vent pipe is connected to the inlet side of the liquid container 1 . The inlet of the introduction pipe 2 a opens to the dry well 11 inside the reactor containment vessel 10 . Further, the outlet of the introduction pipe 2a is open to the upper part inside the liquid container 1. As shown in FIG.

The introduction pipe 2a is a pipe for venting the gas (fluid) inside the reactor containment vessel 10, and is used to introduce the gas (fluid) containing organic iodine into the nonvolatile liquid L1. A pressure release valve 4 is provided in the introduction pipe 2a. The pressure release valve 4 is a normally closed valve that opens at a predetermined set pressure above atmospheric pressure.

A discharge pipe 2b constituting an upstream vent pipe is connected to the outlet side of the liquid container 1. As shown in FIG. The inlet of the discharge pipe 2b opens to the bottom inside the liquid container 1 . The other end of the discharge pipe 2b is connected to the filter vent container 6. As shown in FIG. The outlet of the discharge pipe 2b opens to the liquid phase inside the filter vent container 6 .

The discharge pipe 2 b is a pipe for venting the gas (fluid) inside the reactor containment vessel 10 and is used to discharge the gas (fluid) introduced into the nonvolatile liquid L 1 from the liquid container 1 . An isolation valve 5 is provided in the discharge pipe 2b. The isolation valve 5 is a normally closed valve that can be opened and closed manually or automatically.

The filter vent vessel 6 is used to condense the vented gas and remove radioactive substances contained in the gas. The filter vent container 6 is prepared with scrubbing water L2. The scrubbing water L2 is an aqueous solution in which an alkali such as sodium thiosulfate or sodium hydroxide is dissolved. A scrubber nozzle (not shown) formed of, for example, a multiple venturi nozzle or the like can be attached to the outlet of the discharge pipe 2b. The scrubber nozzle allows the vented gas to be ejected into the liquid as fine bubbles.

The filter vent container 6 has a metal filter 7 at the top of the container. The metal filter 7 is formed by stacking metal fibers, metal mesh, or the like. According to the metal filter 7, the aerosol released into the gas phase in the container can be collected by adhesion to metal, collision, or the like.

A downstream side vent pipe 8 is connected to the secondary side of the metal filter 7 in the filter vent container 6 . The other end of the downstream vent pipe 8 is connected to the exhaust stack 9 . The exhaust stack 9 is provided to discharge the gas vented from the reactor containment vessel 10 into the environment.

The filter vent vessel 6 can also be provided with a baffle (not shown) that resists the high-temperature, high-pressure gas ejected into the liquid. As the baffle, for example, an orifice-shaped baffle plate, a spiral plate, a perforated plate such as a metal mesh or punching metal, a porous body such as ceramic, or the like is used at the height of the liquid phase part in the filter vent container 6. can be provided.

The organic iodine entering the filter vent vessel 6 is presumed to be gaseous. Dissolution of gaseous organic iodine into a liquid and decomposition of organic iodine are thought to proceed by diffusion migration, thermophoresis, Brownian diffusion, convection, and the like in bubbles. If a baffle is provided in the filter vent container 6, the residence time of the bubbles ejected into the liquid is lengthened, and the contact time between the organic iodine and the liquid is lengthened, so the collection efficiency of the organic iodine is enhanced.

Next, a method for collecting organic iodine using the collecting device 100 will be specifically described.

In a nuclear reactor, when a serious accident occurs such that the pressure vessel is damaged, various radioactive materials are released into the containment vessel together with high-temperature, high-pressure steam due to the evaporation of cooling water and the like. It is estimated that about 1 kg of radioactive organic iodine will be released in the event of a severe accident in which the containment vessel is damaged, depending on the output of the reactor and the accident scenario. Methyl iodide (CH ₃ I) having volatility is assumed as the main component of organic iodine.

If a serious accident occurs in a nuclear reactor and the pressure inside the containment vessel becomes excessively high, the containment vessel will burst and cause a large-scale leakage of radioactive materials. Therefore, venting is implemented as a measure to prevent such events. The vented gas (vapor) contains radioactive substances such as noble gases, aerosols, inorganic iodine, and organic iodine. These radioactive substances are collected by the filter vent device 20 and prevented from leaking to the environment.

In the collection device 100, the nonvolatile liquid L1 contained in the liquid container 1 is heated by the heat in the dry well 11 of the nuclear reactor containment vessel 10, and the organic iodine in the dry well 11 of the nuclear reactor containment vessel 10 is contained. A gas (fluid) is passed through the heated nonvolatile liquid L1, and the organic iodine contained in the gas is decomposed into the nonvolatile liquid L1 and collected. The non-volatile liquid L1 is preheated in the liquid container 1 and then transferred to the filter vent container 6 from the liquid container 1 to the filter vent container 6 to decompose the organic iodine.

When high-temperature, high-pressure steam (gas) is released into the reactor containment vessel 10 in the event of a nuclear reactor accident, the temperature and pressure within the reactor containment vessel 10 rise. A liquid container 1 is installed in a dry well 11 inside a nuclear reactor containment vessel 10 . Therefore, the nonvolatile liquid L1 prepared in the liquid container 1 is heated by the heat inside the dry well 11 . The nonvolatile liquid L1 is heated by any of heat conduction from the reactor structural material to the liquid container 1, heat transfer from the gas in the space to the liquid container 1, radiation from the reactor structural material and the gas in the space, and the like. may

In the event of a nuclear reactor accident, high-temperature, high-pressure gas is released into the containment vessel 10, and when the pressure inside the containment vessel 10 exceeds a set pressure, the pressure release valve 4 opens. When the pressure relief valve 4 opens, the high-temperature, high-pressure gas in the drywell 11 flows into the liquid container 1 through the introduction pipe 2a. The nonvolatile liquid L1 prepared in the liquid container 1 is further heated by contact with the inflowing gas and starts to react with the organic iodine in the gas.

When the pressure inside the containment vessel 10 becomes high and it is determined that the dry well 11 needs to be vented, the isolation valve 5 is opened. The isolation valve 5 may open at the same time as the pressure relief valve 4 or may open after the pressure relief valve 4 . When the isolation valve 5 is opened, the nonvolatile liquid L1 prepared in the liquid container 1 is pushed by the high-temperature, high-pressure gas, decomposing the organic iodine, and passing through the discharge pipe 2b to the filter vent container 6. Sent.

The gas vented from the reactor containment vessel 10 jets out into the liquid in the filter vent vessel 6 together with the non-volatile liquid L1. The vented gas is passed through the non-volatile liquid L1 in the filter vent container 6 after all of the prepared non-volatile liquid L1 has been discharged from the liquid container 1 .

In the filter vent container 6, the organic iodine contained in the vented gas reacts with the nonvolatile liquid L1 and is decomposed into iodine ions and organic substances. In addition, dissociated iodine ions, aerosols contained in the vented gas, inorganic iodine, and the like are dissolved in the nonvolatile liquid L1 and the scrubbing water L2 and collected. The aerosol released into the gas phase without being collected in the liquid phase is collected by the metal filter 7 . After that, the gas from which the radioactive substances have been removed is released into the environment through the exhaust stack 9 .

As the nonvolatile liquid L1, a liquid made of a hydrophilic (easily water-soluble) substance may be used, or a liquid made of a hydrophobic (slightly water-soluble) substance may be used. When the non-volatile liquid L1 is hydrophilic, the non-volatile liquid L1 and the scrubbing water L2 are easily mixed. Hydrophilic radioactive substances are easily collected by dissolution, and hydrophobic radioactive substances are easily collected by flocculation/sedimentation. On the other hand, when the nonvolatile liquid L1 is hydrophobic, hydrophobic radioactive substances are easily trapped in the nonvolatile liquid L1, and hydrophilic radioactive substances are easily trapped in the scrubbing water L2.

Further, as the nonvolatile liquid L1, a liquid having a specific gravity higher than that of water or the scrubbing water L2 may be used, or a liquid having a specific gravity lower than that of water or the scrubbing water L2 may be used. When the hydrophobic nonvolatile liquid L1 is used, the liquids are easily phase-separated to form a two-layer liquid. When the nonvolatile liquid L1 has a small specific gravity, the upper layer becomes the nonvolatile liquid L1 and the lower layer becomes the scrubbing water L2. With such a layer structure, volatilization of organic iodine and secondary-generated elemental iodine can be reliably prevented by the nonvolatile liquid L1 in the upper layer. On the other hand, if the nonvolatile liquid L1 has a large specific gravity, the upper layer is the scrubbing water L2 and the lower layer is the nonvolatile liquid L1. With such a layer structure, radioactive substances with low volatility can be collected efficiently by being aggregated and precipitated by the non-volatile liquid L1 in the lower layer.

According to the collection device 100 and the collection method described above, the liquid container 1 is installed in the dry well 11 inside the nuclear reactor containment vessel 10, and the non-volatile liquid L1 is stored in the dry well 11 inside the nuclear reactor containment vessel 10. , the reaction rate between the nonvolatile liquid L1 and the organic iodine during venting can be increased. Since the nonvolatile liquid L1 is preheated before coming into contact with a large amount of organic iodine, the collection efficiency can be increased over a wide period of time including the initial stage of venting. Therefore, it is possible to provide an apparatus and method capable of efficiently collecting organic iodine in the containment vessel.

Further, according to the collection device 100 and the collection method described above, the outlet of the introduction pipe 2a opens to the upper part of the liquid container 1, and the inlet of the discharge pipe 2b opens to the lower part of the liquid container 1. Therefore, the non-volatile liquid L1 prepared in the liquid container 1 can be easily transferred to the filter vent container 6 using the pressure difference between the inside and outside of the reactor containment vessel 10 and the water head of the non-volatile liquid L1. Since the liquid container 1 is depleted after transferring the non-volatile liquid L1, it is possible to avoid a large flow resistance from affecting the gas to be vented. In addition, since the nonvolatile liquid L1 and the organic iodine are transferred to the filter vent container 6, a sufficient reaction time can be ensured, and the reaction product can be trapped in the mixed-phase liquid.

FIG. 2 is a cross-sectional view schematically showing an example of the organic iodine trapping device according to the present invention.
In Figure 2, a liquid container containing a non-volatile liquid that can decompose organic iodine is installed in a dry well in the reactor containment vessel, and the non-volatile liquid is heated by the heat in the reactor containment vessel. Figure 1 shows the collection device used.

As shown in FIG. 2, the collection device 200 according to this embodiment is incorporated in the reactor containment vessel 10 and the filter vent device 20, like the collection device 100 described above. The collection device 200 includes a liquid container 1, upstream vent pipes (2a, 2b), a pressure relief valve 4, an isolation valve 5, a filter vent container 6, a metal filter 7, and a downstream vent pipe 8. , and an exhaust stack 9 .

A collection device 200 according to this embodiment differs from the collection device 100 described above in the piping system associated with the liquid container 1, the introduction pipe 2a, and the discharge pipe 2b. Other device configurations of the collection device 200 are substantially the same as those of the collection device 100 described above.

In the collection device 200 , the entrance of the introduction pipe 2 a opens to the dry well 11 inside the reactor containment vessel 10 . The outlet of the introduction pipe 2a is open to the liquid phase portion on the lower side inside the liquid container 1 . On the other hand, the inlet of the discharge pipe 2b is open to the gas phase portion on the upper side inside the liquid container 1 . The outlet of the discharge pipe 2b opens to the liquid phase inside the filter vent container 6 .

With such a piping system, the liquid container 1 can function as a wet filter. A scrubber nozzle formed by, for example, a multiple venturi nozzle or the like can be attached to the outlet of the introduction pipe 2a. Also, the liquid container 1 functioning as a wet filter can be provided with a baffle that exerts resistance against the high-temperature, high-pressure gas ejected into the liquid, similarly to the filter vent container 6 .

Next, a method for collecting organic iodine using the collecting device 200 will be specifically described.

In the collection device 200, the non-volatile liquid L1 contained in the liquid container 1 is heated by the heat in the dry well 11 of the nuclear reactor containment vessel 10, and the organic iodine in the dry well 11 of the nuclear reactor containment vessel 10 is contained. A gas (fluid) is passed through the heated nonvolatile liquid L1, and the organic iodine contained in the gas is decomposed into the nonvolatile liquid L1 and collected. The nonvolatile liquid L1 decomposes the organic iodine while being heated within the liquid container 1 .

When high-temperature, high-pressure steam (gas) is released into the reactor containment vessel 10 in the event of a nuclear reactor accident, the temperature and pressure within the reactor containment vessel 10 rise. A liquid container 1 is installed in a dry well 11 inside a nuclear reactor containment vessel 10 . Therefore, the nonvolatile liquid L1 prepared in the liquid container 1 is heated by the heat inside the dry well 11 .

In the event of a nuclear reactor accident, high-temperature, high-pressure gas is released into the containment vessel 10, and when the pressure inside the dry well 11 exceeds a set pressure, the pressure release valve 4 opens. When the pressure relief valve 4 opens, the high-temperature, high-pressure gas in the drywell 11 flows into the liquid container 1 through the introduction pipe 2a. The nonvolatile liquid L1 prepared in the liquid container 1 is further heated by contact with the inflowing gas and starts to react with the organic iodine in the gas.

In the liquid container 1, the organic iodine contained in the vented gas reacts with the nonvolatile liquid L1 and decomposes into iodine ions and organic matter. In addition, dissociated iodine ions, aerosols contained in the vented gas, inorganic iodine, etc. are dissolved in the nonvolatile liquid L1 and collected.

When the pressure inside the containment vessel 10 becomes high and it is determined that the dry well 11 and the liquid container 1 need to be vented, the isolation valve 5 is opened. The isolation valve 5 may be opened simultaneously with the pressure release valve 4 , may be opened before the pressure release valve 4 , or may be opened after the pressure release valve 4 . When the isolation valve 5 is opened, the radioactive substances released into the gas phase without being captured in the liquid phase in the liquid container 1 are sent to the filter vent container 6 through the discharge pipe 2b.

In the filter vent container 6, radioactive substances remaining in the vented gas are dissolved and aggregated in the scrubbing water L2 and collected. The aerosol released into the gas phase without being collected in the liquid phase is collected by the metal filter 7 . After that, the gas from which the radioactive substances have been removed is released into the environment through the exhaust stack 9 .

According to the collection device 200 and the collection method described above, the liquid container 1 is installed in the dry well 11 inside the containment vessel 10, and the non-volatile liquid L1 is stored in the dry well 11 inside the containment vessel 10. , the reaction rate between the nonvolatile liquid L1 and the organic iodine during venting can be increased. Since the non-volatile liquid L1 is preheated before contact with a large amount of organic iodine and heated during the reaction, the collection efficiency can be increased over a wide period of time including the initial stage of venting. Therefore, it is possible to provide an apparatus and method capable of efficiently collecting organic iodine in the containment vessel.

Further, according to the collection device 200 and the collection method described above, the outlet of the introduction pipe 2a is open to the liquid phase portion on the lower side in the liquid container 1, and the inlet of the discharge pipe 2b is connected to the liquid container 1. Since it is open to the gas phase portion on the inner upper side, collection can be continued in the liquid container 1 . Since organic iodine and other radioactive materials are collected within the containment vessel boundary, the risk of leakage of the collected radioactive materials can be further reduced.

FIG. 3 is a cross-sectional view schematically showing an example of the organic iodine trapping device according to the present invention.
In FIG. 3, a liquid container containing a non-volatile liquid capable of decomposing organic iodine is installed outside the containment vessel, and the non-volatile liquid is heated by the heat inside the containment vessel. shows a collection device.

As shown in FIG. 3, a collection device 300 according to this embodiment is incorporated in the reactor containment vessel 10 and the filter vent device 20 in the same manner as the collection device 100 described above. The collection device 300 includes a liquid container 1, upstream vent pipes (2a, 2b), an isolation valve 5, a filter vent container 6, a metal filter 7, a downstream vent pipe 8, an exhaust pipe 9, A circulation pipe 13 is provided.

The collection device 300 according to the present embodiment differs from the collection device 100 described above in that the liquid container 1 is installed outside the reactor containment vessel 10 and the circulation pipe 13 is connected to the liquid container 1. This is the point. Other device configurations of the collection device 300 are substantially the same as those of the collection device 100 described above.

In the collection device 200, the liquid container 1 is connected in the middle of the upstream vent pipes (2a, 2b). The liquid container 1 is installed outside the reactor containment vessel 10 . The liquid container 1 may be installed inside the reactor building or outside the reactor building as long as it is outside the reactor containment vessel 10 .

An inlet pipe 2a forming an upstream vent pipe is connected to the inlet side of the liquid container 1, as in the collecting device 100 described above. An isolation valve 5 is provided in the introduction pipe 2a. A discharge pipe 2b constituting an upstream vent pipe is connected to the outlet side of the liquid container 1, as in the collecting device 100 described above.

With such a piping system, the liquid container 1 can function as a wet filter. A scrubber nozzle formed by, for example, a multiple venturi nozzle or the like can be attached to the outlet of the introduction pipe 2a. Also, the liquid container 1 functioning as a wet filter can be provided with a baffle that exerts resistance against the high-temperature, high-pressure gas ejected into the liquid, similarly to the filter vent container 6 .

The circulation pipe 13 forms a closed annular flow path from the liquid container 1 through the dry well 11 of the reactor containment vessel 10 and back to the liquid container 1 . One end of the circulation pipe 13 is connected to the lower part of the liquid container 1, and the other end is connected to the upper part thereof. An intermediate portion of the circulation pipe 13 is located inside the drywell 11, and the pipe line is laid vertically along the vertical direction.

According to the circulation pipe 13, when the non-volatile liquid L1 inside the circulation pipe 13 is heated by the heat inside the containment vessel 10, the non-volatile liquid L1 can be circulated by natural convection. When the nonvolatile liquid L1 is heated in the intermediate portion of the circulation pipe 13, the nonvolatile liquid L1 in the intermediate portion of the circulation pipe 13 rises, and the nonvolatile liquid L1 in the liquid container 1, which has a lower temperature, descends. Non-volatile liquid L1 naturally circulates.

Next, a method for collecting organic iodine using the collecting device 300 will be specifically described.

In the collection device 300, the non-volatile liquid L1 contained in the liquid container 1 is heated by the heat in the dry well 11 of the containment vessel 10, and the organic iodine contained in the dry well 11 of the containment vessel 10 is heated. A gas (fluid) is passed through the heated nonvolatile liquid L1, and the organic iodine contained in the gas is decomposed into the nonvolatile liquid L1 and collected. The nonvolatile liquid L1 decomposes the organic iodine while being heated within the liquid container 1 .

When high-temperature, high-pressure steam (gas) is released into the reactor containment vessel 10 in the event of a nuclear reactor accident, the temperature and pressure within the reactor containment vessel 10 rise. Although the liquid container 1 is installed outside the reactor containment vessel 10, the non-volatile liquid L1 in the circulation pipe 13 passing through the reactor containment vessel 10 is heated. Therefore, the nonvolatile liquid L1 is heated by the heat in the reactor containment vessel 10 while naturally circulating through the circulation pipe 13 between the liquid vessel 1 and the reactor containment vessel 10 .

When the pressure inside the containment vessel 10 becomes high and it is determined that the dry well 11 needs to be vented, the isolation valve 5 is opened. When the isolation valve 5 is opened, the high-temperature, high-pressure gas in the drywell 11 flows into the liquid container 1 through the introduction pipe 2a. The nonvolatile liquid L1 prepared in the liquid container 1 is further heated by contact with the inflowing gas and starts to react with the organic iodine in the gas.

In the liquid container 1, radioactive substances contained in the vented gas are collected by the nonvolatile liquid L1, similarly to the collection device 200 described above. In the filter vent container 6, as in the collecting device 200 described above, radioactive substances released into the gas phase without being collected in the liquid phase in the liquid container 1 are collected by the scrubbing water L2 and the metal filter 7. be collected.

According to the collection device 300 and the collection method described above, the liquid container 1 is installed outside the reactor containment vessel 10, but the nonvolatile liquid L1 is Since the liquid container 1 is heated, the reaction rate between the nonvolatile liquid L1 and the organic iodine during venting can be increased without providing an installation location for the liquid container 1 in the reactor containment vessel 10 . Since the non-volatile liquid L1 is preheated before contact with a large amount of organic iodine and heated during the reaction, the collection efficiency can be increased over a wide period of time including the initial stage of venting. Therefore, it is possible to provide an apparatus and method capable of efficiently collecting organic iodine in the containment vessel.

Further, according to the collection device 300 and the collection method described above, the outlet of the introduction pipe 2a is open to the liquid phase portion on the lower side in the liquid container 1, and the inlet of the discharge pipe 2b is connected to the liquid container 1. Since it is open to the gas phase portion on the inner upper side, collection can be continued in the liquid container 1 in the same manner as the collection device 200 described above. Since the non-volatile liquid L1 in the liquid container 1 is entirely heated by natural circulation, there is no need for forced circulation using a pump or the like, and high collection efficiency can be obtained even when power is lost. In addition, since the liquid is agitated by natural circulation, the nonvolatile liquid L1 and the organic iodine can be efficiently reacted.

FIG. 4 is a cross-sectional view schematically showing an example of the organic iodine trapping device according to the present invention.
In FIG. 4, a liquid container containing a non-volatile liquid that can decompose organic iodine is installed in a dry well in the reactor containment vessel, and the non-volatile liquid is heated by the heat in the reactor containment vessel. Figure 1 shows the collection device used.

As shown in FIG. 4, a collection device 400 according to this embodiment is incorporated in the reactor containment vessel 10 and the filter vent device 20, like the collection device 100 described above. The collection device 400 includes a liquid container 1, upstream vent pipes (2a, 2b), a pressure release valve 4, an isolation valve 5, a filter vent container 6, a metal filter 7, and a downstream vent pipe 8. , and an exhaust stack 9 .

A collection device 400 according to this embodiment differs from the collection device 100 described above in the piping system associated with the introduction pipe 2a. Other device configurations of the collection device 400 are substantially the same as those of the collection device 100 described above.

In the collection device 400 , the inlet of the introduction pipe 2 a opens to the wet well 12 inside the reactor containment vessel 10 . The outlet of the introduction pipe 2 a opens to the upper part of the liquid container 1 . A pressure release valve 4 is provided in the introduction pipe 2a. On the other hand, the inlet of the discharge pipe 2b is open at the bottom inside the liquid container 1. As shown in FIG. The outlet of the discharge pipe 2b opens to the liquid phase inside the filter vent container 6 . An isolation valve 5 is provided in the discharge pipe 2b.

Next, a method for collecting organic iodine using the collecting device 400 will be specifically described.

In the collection device 400, the non-volatile liquid L1 contained in the liquid container 1 is heated by the heat in the dry well 11 of the containment vessel 10, and the organic iodine contained in the wet well 12 of the containment vessel 10 is heated. A gas (fluid) is passed through the heated nonvolatile liquid L1, and the organic iodine contained in the gas is decomposed into the nonvolatile liquid L1 and collected. The non-volatile liquid L1 is preheated in the liquid container 1 and then transferred to the filter vent container 6 from the liquid container 1 to the filter vent container 6 to decompose the organic iodine.

When high-temperature, high-pressure steam (gas) is released into the reactor containment vessel 10 in the event of a nuclear reactor accident, the temperature and pressure within the reactor containment vessel 10 rise. A liquid container 1 is installed in a dry well 11 inside a nuclear reactor containment vessel 10 . Therefore, the nonvolatile liquid L1 prepared in the liquid container 1 is heated by the heat inside the dry well 11 .

In the event of a nuclear reactor accident, high-temperature, high-pressure gas is released into the reactor containment vessel 10, and when the pressure in the wetwell 12 exceeds a set pressure, the pressure release valve 4 opens. When the pressure release valve 4 opens, the high-temperature, high-pressure gas in the wetwell 12 flows into the liquid container 1 through the introduction pipe 2a. The nonvolatile liquid L1 prepared in the liquid container 1 is further heated by contact with the inflowing gas and starts to react with the organic iodine in the gas.

When the pressure inside the containment vessel 10 becomes high and it is determined that the wetwell 12 needs to be vented, the isolation valve 5 is opened. The isolation valve 5 may open at the same time as the pressure relief valve 4 or may open after the pressure relief valve 4 . When the isolation valve 5 is opened, the nonvolatile liquid L1 prepared in the liquid container 1 is pushed by the high-temperature, high-pressure gas, decomposing the organic iodine, and passing through the discharge pipe 2b to the filter vent container 6. Sent.

In the filter vent container 6, radioactive substances contained in the vented gas are collected by the nonvolatile liquid L1, the scrubbing water L2, and the metal filter 7, similarly to the collection device 100 described above.

According to the collection device 400 and the collection method described above, the liquid container 1 is installed in the dry well 11 inside the nuclear reactor containment vessel 10, and the non-volatile liquid L1 is stored in the dry well 11 inside the nuclear reactor containment vessel 10. , the reaction rate between the nonvolatile liquid L1 and the organic iodine during venting can be increased. Since the nonvolatile liquid L1 is preheated before coming into contact with a large amount of organic iodine, the collection efficiency can be increased over a wide period of time including the initial stage of venting. Therefore, it is possible to provide an apparatus and method capable of efficiently collecting organic iodine in the containment vessel.

In addition, according to the collection device 400 and the collection method described above, since the inlet of the introduction pipe 2a is open to the wet well 12 in the reactor containment vessel 10, the non-condensable gas in the wet well 12 is removed. When venting, efficient collection of organic iodine can occur. Within the wetwell 12, some of the radioactive material in the gas is pre-collected in the pool water, thus providing a safer vent. In addition, since the liquid container 1 is installed in the dry well 11, compared to the case where it is installed in the wet well 12, higher heat can be used to heat the nonvolatile liquid L1.

FIG. 5 is a cross-sectional view schematically showing an example of the organic iodine trapping device according to the present invention.
In FIG. 5, a liquid container containing a non-volatile liquid capable of decomposing organic iodine is installed outside the containment vessel, and the non-volatile liquid is heated by the heat inside the containment vessel. shows a collection device.

As shown in FIG. 5, a collection device 500 according to this embodiment is incorporated in the reactor containment vessel 10 and the filter vent device 20 in the same manner as the collection device 300 described above. The collection device 500 includes a liquid container 1, upstream vent pipes (2a, 2b), an isolation valve 5, a filter vent container 6, a metal filter 7, a downstream vent pipe 8, an exhaust pipe 9, A circulation pipe 13 is provided.

A collection device 500 according to this embodiment differs from the collection device 300 described above in the piping system related to the introduction pipe 2a. Other device configurations of the collection device 500 are substantially the same as those of the collection device 300 described above.

In the collection device 500 , the wet well 12 is connected to upstream vent pipes ( 2 a, 2 b ) for venting the gas inside the containment vessel 10 . A liquid container 1 is connected in the middle of the upstream vent pipes (2a, 2b). The liquid container 1 is installed outside the reactor containment vessel 10 . The liquid container 1 may be installed inside the reactor building or outside the reactor building as long as it is outside the reactor containment vessel 10 .

An inlet pipe 2a constituting an upstream vent pipe is connected to the inlet side of the liquid container 1 . An inlet of the introduction pipe 2 a opens to a wet well 12 inside the reactor containment vessel 10 . The outlet of the introduction pipe 2a is open to the liquid phase portion on the lower side inside the liquid container 1 . An isolation valve 5 is provided in the introduction pipe 2a.

A discharge pipe 2b constituting an upstream vent pipe is connected to the outlet side of the liquid container 1. As shown in FIG. The inlet of the discharge pipe 2b opens to the gas phase portion on the upper side inside the liquid container 1 . The other end of the discharge pipe 2 b is connected to the filter vent container 6 . The outlet of the discharge pipe 2b opens to the liquid phase inside the filter vent container 6 .

With such a piping system, the liquid container 1 can function as a wet filter. The circulation pipe 13 forms a closed annular flow path from the liquid container 1 through the dry well 11 of the reactor containment vessel 10 and back to the liquid container 1, like the collection device 300 described above.

Next, a method for collecting organic iodine using the collecting device 500 will be specifically described.

In the collection device 500, the nonvolatile liquid L1 in the liquid container 1 is heated by the heat in the dry well 11 of the containment vessel 10, and the organic iodine contained in the wet well 12 of the containment vessel 10 is heated. A gas (fluid) is passed through the heated nonvolatile liquid L1, and the organic iodine contained in the gas is decomposed into the nonvolatile liquid L1 and collected. The nonvolatile liquid L1 decomposes the organic iodine while being heated within the liquid container 1 .

When high-temperature, high-pressure steam (gas) is released into the reactor containment vessel 10 in the event of a nuclear reactor accident, the temperature and pressure within the reactor containment vessel 10 rise. Although the liquid container 1 is installed outside the reactor containment vessel 10, the non-volatile liquid L1 in the circulation pipe 13 passing through the reactor containment vessel 10 is heated. Therefore, the nonvolatile liquid L1 is heated by the heat in the reactor containment vessel 10 while naturally circulating through the circulation pipe 13 between the liquid vessel 1 and the reactor containment vessel 10 .

Further, when it is determined that the wetwell 12 needs to be vented in the event of a nuclear reactor accident, the isolation valve 5 is opened. When the isolation valve 5 is opened, the high-temperature, high-pressure gas in the wetwell 12 flows into the liquid container 1 through the introduction pipe 2a. The nonvolatile liquid L1 prepared in the liquid container 1 is further heated by contact with the inflowing gas and starts to react with the organic iodine in the gas.

In the liquid container 1, radioactive substances contained in the vented gas are collected by the nonvolatile liquid L1 in the same manner as in the collection device 300 described above. In the filter vent container 6, as in the collecting device 200 described above, radioactive substances released into the gas phase without being collected in the liquid phase in the liquid container 1 are collected by the scrubbing water L2 and the metal filter 7. be collected.

According to the collection device 500 and the collection method described above, the liquid container 1 is installed outside the containment vessel 10, but the non-volatile liquid L1 is Since the liquid container 1 is heated, the reaction rate between the nonvolatile liquid L1 and the organic iodine during venting can be increased without providing an installation location for the liquid container 1 in the reactor containment vessel 10 . Since the non-volatile liquid L1 is preheated before contact with a large amount of organic iodine and heated during the reaction, the collection efficiency can be increased over a wide period of time including the initial stage of venting. Therefore, it is possible to provide an apparatus and method capable of efficiently collecting organic iodine in the containment vessel.

Further, according to the collection device 500 and the collection method described above, the outlet of the introduction pipe 2a is open to the liquid phase portion on the lower side in the liquid container 1, and the inlet of the discharge pipe 2b is connected to the liquid container 1. Since it is open to the gas phase portion on the inner upper side, collection can be continued in the liquid container 1 in the same manner as the collection device 300 described above. Since the non-volatile liquid L1 in the liquid container 1 is entirely heated by natural circulation, there is no need for forced circulation using a pump or the like, and high collection efficiency can be obtained even when power is lost. In addition, since the liquid is agitated by natural circulation, the nonvolatile liquid L1 and the organic iodine can be efficiently reacted.

FIG. 6 is a cross-sectional view schematically showing an example of the organic iodine trapping device according to the present invention.
In FIG. 6, a liquid container containing a non-volatile liquid that can decompose organic iodine is installed in a wet well in the reactor containment vessel, and the non-volatile liquid is heated by the heat in the reactor containment vessel. Figure 1 shows the collection device used.

As shown in FIG. 6, a collection device 600 according to this embodiment is incorporated in the reactor containment vessel 10 and the filter vent device 20 in the same manner as the collection device 100 described above. The collection device 600 includes a liquid container 1, upstream vent pipes (2a, 2b), a pressure relief valve 4, an isolation valve 5, a filter vent container 6, a metal filter 7, and a downstream vent pipe 8. , and an exhaust stack 9 .

A collection device 600 according to this embodiment differs from the collection device 100 described above in the installation position of the liquid container 1 and the piping system related to the introduction pipe 2a and the discharge pipe 2b. Other device configurations of the collection device 600 are substantially the same as those of the collection device 100 described above.

In the collection device 600 , the wet well 12 is connected to upstream vent pipes ( 2 a, 2 b ) for venting the gas inside the containment vessel 10 . A liquid container 1 is connected in the middle of the upstream vent pipes (2a, 2b). A liquid container 1 is installed in a wet well 12 of a nuclear reactor containment vessel 10 .

An inlet pipe 2a constituting an upstream vent pipe is connected to the inlet side of the liquid container 1 . An inlet of the introduction pipe 2 a opens to a wet well 12 inside the reactor containment vessel 10 . The outlet of the introduction pipe 2 a opens to the upper part of the liquid container 1 . A pressure release valve 4 is provided in the introduction pipe 2a.

A discharge pipe 2b constituting an upstream vent pipe is connected to the outlet side of the liquid container 1. As shown in FIG. The inlet of the discharge pipe 2b opens to the bottom inside the liquid container 1 . The other end of the discharge pipe 2 b is connected to the filter vent container 6 . The outlet of the discharge pipe 2b opens to the liquid phase inside the filter vent container 6 . An isolation valve 5 is provided in the discharge pipe 2b.

Next, a method for collecting organic iodine using the collecting device 600 will be specifically described.

In the collection device 600, the nonvolatile liquid L1 placed in the liquid container 1 is heated by the heat in the wet well 12 of the reactor containment vessel 10, and the organic iodine in the wet well 12 of the reactor containment vessel 10 is heated. A gas (fluid) is passed through the heated nonvolatile liquid L1, and the organic iodine contained in the gas is decomposed into the nonvolatile liquid L1 and collected. The non-volatile liquid L1 is preheated in the liquid container 1 and then transferred to the filter vent container 6 from the liquid container 1 to the filter vent container 6 to decompose the organic iodine.

When high-temperature, high-pressure steam (gas) is released into the reactor containment vessel 10 in the event of a nuclear reactor accident, the temperature and pressure within the reactor containment vessel 10 rise. The liquid container 1 is installed in a wetwell 12 inside the reactor containment vessel 10 . Therefore, the nonvolatile liquid L1 prepared in the liquid container 1 is heated by the heat inside the wet well 12 .

In the event of a nuclear reactor accident, high-temperature, high-pressure gas is released into the reactor containment vessel 10, and when the pressure in the wetwell 12 exceeds a set pressure, the pressure release valve 4 opens. When the pressure release valve 4 opens, the high-temperature, high-pressure gas in the wetwell 12 flows into the liquid container 1 through the introduction pipe 2a. The nonvolatile liquid L1 prepared in the liquid container 1 is further heated by contact with the inflowing gas and starts to react with the organic iodine in the gas.

When the pressure inside the containment vessel 10 becomes high and it is determined that the wetwell 12 needs to be vented, the isolation valve 5 is opened. The isolation valve 5 may open at the same time as the pressure relief valve 4 or may open after the pressure relief valve 4 . When the isolation valve 5 is opened, the nonvolatile liquid L1 prepared in the liquid container 1 is pushed by the high-temperature, high-pressure gas, decomposing the organic iodine, and passing through the discharge pipe 2b to the filter vent container 6. Sent.

In the filter vent container 6, radioactive substances contained in the vented gas are collected by the nonvolatile liquid L1, the scrubbing water L2, and the metal filter 7, similarly to the collection device 100 described above.

According to the collection device 600 and the collection method described above, the liquid container 1 is installed in the wet well 12 inside the nuclear reactor containment vessel 10, and the non-volatile liquid L1 is placed in the wet well 12 inside the nuclear reactor containment vessel 10. , the reaction rate between the nonvolatile liquid L1 and the organic iodine during venting can be increased. Since the nonvolatile liquid L1 is preheated before coming into contact with a large amount of organic iodine, the collection efficiency can be increased over a wide period of time including the initial stage of venting. Therefore, it is possible to provide an apparatus and method capable of efficiently collecting organic iodine in the containment vessel.

Further, according to the collection device 600 and the collection method described above, since the inlet of the introduction pipe 2a is open to the wet well 12 in the reactor containment vessel 10, the non-condensable gas in the wet well 12 is removed. Efficient collection of organic iodine can be performed during venting. Also, since the liquid container 1 is installed in the wet well 12, it is possible to avoid exposing the liquid container 1 and the nonvolatile liquid L1 to extremely high temperatures, compared with the case of installing the liquid container 1 in the dry well 11.例文帳に追加

FIG. 7 is a cross-sectional view schematically showing an example of the organic iodine trapping device according to the present invention.
In FIG. 7, a liquid container containing a non-volatile liquid that can decompose organic iodine is installed in a dry well in the reactor containment vessel, and the non-volatile liquid Fig. 2 shows the heat of reaction of the fluid in the reactor containment vessel and the collection device heated by;

As shown in FIG. 7, a collection device 700 according to this embodiment is incorporated in the reactor containment vessel 10 and the filter vent device 20 in the same manner as the collection device 100 described above. The collection device 700 includes a liquid container 1, upstream vent pipes (2a, 2b), a pressure relief valve 4, an isolation valve 5, a filter vent container 6, a metal filter 7, and a downstream vent pipe 8. , an exhaust stack 9 and a reactor 14 .

A collection device 700 according to this embodiment differs from the collection device 100 described above in that a reactor 14 that generates heat of reaction is provided around the liquid container 1 . Other device configurations of the collection device 700 are substantially the same as those of the collection device 100 described above.

The reactor 14 is a device that supports a reactant that reacts with the substance released into the containment vessel 10, and exothermically reacts the gas (fluid) released into the containment vessel 10 to generate reaction heat. is used. As the reactant, any substance that reacts with any substance released into the containment vessel 10 can be used as long as it causes an exothermic reaction. In particular, a substance that reacts with hydrogen or steam to generate heat is preferably used. be done. As the reaction material, for example, a hydrogen recombination catalyst or a metal oxide catalyst that produces water through a reaction between hydrogen and oxygen, an ammonia synthesis catalyst that produces ammonia through a reaction between hydrogen and nitrogen, a hydrogen storage alloy, or the like can be used. can be done.

Examples of hydrogen recombination catalysts include catalysts in which a metal such as palladium or platinum is impregnated on a carrier. Examples of metal oxide catalysts include catalysts containing metals such as lithium, sodium, magnesium, calcium, iron, nickel, copper, strontium, silver, and cerium. Examples of ammonia synthesis catalysts include catalysts using iron, molybdenum, ruthenium, osmium, etc. as active metals. Examples of hydrogen storage alloys include alloys containing lithium, magnesium, titanium, iron, nickel, lanthanum, and the like.

In the collection device 700 , as the reactor 14 , an indoor installation type device is arranged so as to surround the side surface of the liquid container 1 . However, as long as the reactor 14 is of the indoor installation type, the arrangement, number of installations, shape, reaction method, etc. are not particularly limited. The nonvolatile liquid L1 placed in the liquid container 1 can be heated using any of heat transfer from the reactor 14 to the liquid container 1, heat transfer from the gas heated by the exothermic reaction to the liquid container 1, and the like. good.

As the indoor installation type reactor 14, for example, a chimney type in which the reactants are arranged inside a cylindrical container and a gas passage is provided in the center, or a plurality of reactants are arranged in a cylindrical container at intervals. A parallel type in which the reaction materials are arranged side by side and gas passages are provided between the adjacent reaction materials. Gas flows into the container containing the reactant from the lower side of the gas passage, contacts the surrounding reactant, and causes an exothermic reaction. The heated gas generates an upward flow in the gas passage and is discharged from the upper side of the gas passage.

As the reactor 14, a cartridge container which is easy to replace and filled with the reaction material is preferably used. The liquid container 1 may be provided with a jacket-type heat exchanger so that the gas discharged from the gas passage of the reactor 14 is drawn into the heat exchanger provided around the liquid container 1 . When installing the reactor 14 around the liquid container 1 , it is preferable to install a blower to send gas to the gas passage of the reactor 14 .

Next, a method for collecting organic iodine using the collecting device 700 will be specifically described.

In the collection device 700, the non-volatile liquid L1 contained in the liquid container 1 is heated by the heat in the dry well 11 of the nuclear reactor containment vessel 10 and the reaction heat of the fluid in the nuclear reactor containment vessel. The gas (fluid) containing organic iodine in the dry well 11 of the containment vessel 10 is passed through the heated nonvolatile liquid L1, and the organic iodine contained in the gas is decomposed into the nonvolatile liquid L1 and collected. do. The non-volatile liquid L1 is preheated in the liquid container 1 and then transferred to the filter vent container 6 from the liquid container 1 to the filter vent container 6 to decompose the organic iodine.

When high-temperature, high-pressure steam (gas) is released into the reactor containment vessel 10 in the event of a nuclear reactor accident, the temperature and pressure within the reactor containment vessel 10 rise. A liquid container 1 is installed in a dry well 11 inside a nuclear reactor containment vessel 10 . Therefore, the nonvolatile liquid L1 prepared in the liquid container 1 is heated by the heat inside the dry well 11 .

In the event of a nuclear reactor accident, when the temperature of the core becomes high, the coolant water reacts with the zirconium of the fuel rod cladding, generating a large amount of hydrogen. Since the hydrogen and water vapor released into the containment vessel 10 come into contact with the predetermined reactants in the reactor 14 and generate an exothermic reaction, the non-volatile liquid L1 in the liquid vessel 1 is heated to a higher temperature.

In the event of a nuclear reactor accident, high-temperature, high-pressure gas is released into the containment vessel 10, and when the pressure inside the dry well 11 exceeds a set pressure, the pressure release valve 4 opens. When the pressure relief valve 4 opens, the high-temperature, high-pressure gas in the drywell 11 flows into the liquid container 1 through the introduction pipe 2a. The nonvolatile liquid L1 prepared in the liquid container 1 is further heated by contact with the inflowing gas and starts to react with the organic iodine in the gas.

When the pressure inside the containment vessel 10 becomes high and it is determined that the dry well 11 needs to be vented, the isolation valve 5 is opened. The isolation valve 5 may open at the same time as the pressure relief valve 4 or may open after the pressure relief valve 4 . When the isolation valve 5 is opened, the nonvolatile liquid L1 prepared in the liquid container 1 is pushed by the high-temperature, high-pressure gas, decomposing the organic iodine, and passing through the discharge pipe 2b to the filter vent container 6. Sent.

In the filter vent container 6, radioactive substances contained in the vented gas are collected by the nonvolatile liquid L1, the scrubbing water L2, and the metal filter 7, similarly to the collection device 100 described above.

According to the collection device 700 and the collection method described above, the liquid container 1 is installed in the dry well 11 inside the nuclear reactor containment vessel 10, and the non-volatile liquid L1 is stored in the dry well 11 inside the nuclear reactor containment vessel 10. and the reaction heat of the fluid in the containment vessel 10, the reaction rate between the nonvolatile liquid L1 and the organic iodine during venting can be further increased. Since the nonvolatile liquid L1 is preheated before coming into contact with a large amount of organic iodine, the collection efficiency can be increased over a wide period of time including the initial stage of venting. Therefore, it is possible to provide an apparatus and method capable of efficiently collecting organic iodine in the containment vessel.

In addition, according to the collection device 700 and the collection method described above, since the reactor 14 that generates reaction heat is provided around the liquid container 1, in preheating the nonvolatile liquid L1 with the reaction heat, installation of the reactor 14 is required. The degree of freedom and the degree of freedom in the filling state of the reactants in the reactor 14 are increased. By arranging the reactor 14 around the liquid container 1 and forming an open space near the entrance of the introduction pipe 2a, it is possible to avoid a large flow resistance from affecting the vented gas.

FIG. 8 is a cross-sectional view schematically showing an example of the organic iodine trapping device according to the present invention.
In FIG. 8, a liquid container containing a non-volatile liquid that can decompose organic iodine is installed in a dry well in a nuclear reactor containment vessel, and the non-volatile liquid is heat in the reactor containment vessel, Fig. 2 shows the heat of reaction of the fluid in the reactor containment vessel and the collection device heated by;

As shown in FIG. 8, a collection device 800 according to this embodiment is incorporated in the reactor containment vessel 10 and the filter vent device 20 in the same manner as the collection device 700 described above. The collection device 800 includes a liquid container 1, upstream vent pipes (2a, 2b), a pressure release valve 4, an isolation valve 5, a filter vent container 6, a metal filter 7, and a downstream vent pipe 8. , an exhaust stack 9 and a reactor 14 .

A collection device 800 according to this embodiment differs from the collection device 700 described above in that a reactor 14 that generates heat of reaction is provided in the introduction pipe 2a. Other device configurations of the collection device 800 are substantially the same as those of the collection device 700 described above.

In the collection device 800, as the reactor 14, an in-line type device is connected in the middle of the introduction pipe 2a. However, as long as the reactor 14 is of the in-line type, the arrangement, number of connections, shape, reaction method, etc. are not particularly limited. The non-volatile liquid L1 placed in the liquid container 1 can be heated by heat transfer from the reactor 14 to the liquid container 1, heat transfer from the gas heated by the exothermic reaction in the reactor 14, or the like. good.

Examples of the in-line reactor 14 include a reactor in which a bulk reactant is filled in a cylindrical container, a reactor in which a cartridge filled with a reactant is contained in a cylindrical container, and a cylindrical reactor. and a reactor in which reaction materials formed in a container are laminated and arranged. The gas flows into the cylindrical container from one end of the gas passage, contacts the surrounding reaction material, and causes an exothermic reaction. The heated gas is discharged from the other end side of the gas passage. A plurality of in-line reactors 14 can be arranged in parallel and connected to the liquid container 1 .

Next, a method for collecting organic iodine using the collecting device 800 will be specifically described.

In the collection device 800, the non-volatile liquid L1 contained in the liquid container 1 is heated by the heat in the dry well 11 of the nuclear reactor containment vessel 10 and the reaction heat of the fluid in the nuclear reactor containment vessel. The gas (fluid) containing organic iodine in the dry well 11 of the containment vessel 10 is passed through the heated nonvolatile liquid L1, and the organic iodine contained in the gas is decomposed into the nonvolatile liquid L1 and collected. do. The non-volatile liquid L1 is preheated in the liquid container 1, transferred to the filter vent container 6, and further heated from the liquid container 1 to the filter vent container 6 by reaction heat to decompose the organic iodine.

When high-temperature, high-pressure steam (gas) is released into the reactor containment vessel 10 in the event of a nuclear reactor accident, the temperature and pressure within the reactor containment vessel 10 rise. A liquid container 1 is installed in a dry well 11 inside a nuclear reactor containment vessel 10 . Therefore, the nonvolatile liquid L1 prepared in the liquid container 1 is heated by the heat inside the dry well 11 .

In the event of a nuclear reactor accident, when the temperature of the core becomes high, the coolant water reacts with the zirconium of the fuel rod cladding, generating a large amount of hydrogen. Also, when high-temperature, high-pressure gas is released into the reactor containment vessel 10 and the pressure inside the dry well 11 exceeds the set pressure, the pressure release valve 4 opens. When the pressure release valve 4 opens, gas containing hydrogen and water vapor in the drywell 11 flows into the reactor 14 through the introduction pipe 2a. Since hydrogen and water vapor come into contact with predetermined reactants in the reactor 14 and cause an exothermic reaction, the gas flowing into the reactor 14 becomes hotter and flows into the liquid container 1 . The non-volatile liquid L1 prepared in the liquid container 1 is further heated by such gas and starts to react with the organic iodine in the gas.

When the pressure inside the containment vessel 10 becomes high and it is determined that venting of the drywell 11 is necessary in the event of a nuclear reactor accident, the isolation valve 5 is opened. The isolation valve 5 may open at the same time as the pressure relief valve 4 or may open after the pressure relief valve 4 . When the isolation valve 5 is opened, the nonvolatile liquid L1 prepared in the liquid container 1 is pushed by the high-temperature, high-pressure gas, decomposing the organic iodine, and passing through the discharge pipe 2b to the filter vent container 6. Sent.

In the filter vent container 6, radioactive substances contained in the vented gas are collected by the nonvolatile liquid L1, the scrubbing water L2, and the metal filter 7, similarly to the collection device 700 described above.

According to the collection device 800 and the collection method described above, the liquid container 1 is installed in the dry well 11 inside the nuclear reactor containment vessel 10, and the non-volatile liquid L1 is stored in the dry well 11 inside the nuclear reactor containment vessel 10. and the reaction heat of the fluid in the containment vessel 10, the reaction rate between the nonvolatile liquid L1 and the organic iodine during venting can be further increased. Since the nonvolatile liquid L1 is preheated before coming into contact with a large amount of organic iodine, the collection efficiency can be increased over a wide period of time including the initial stage of venting. Therefore, it is possible to provide an apparatus and method capable of efficiently collecting organic iodine in the containment vessel.

In addition, according to the collection device 800 and the collection method described above, since the reactor 14 that generates reaction heat is provided in the middle of the introduction pipe 2a, substances in the reactor containment vessel 10 that generate exothermic reactions are removed from the reactor containment vessel. A pressure difference across 10 allows it to flow into reactor 14 . Since there is no need to install a blower or the like for sending gas, high collection efficiency can be obtained even when power is lost.

FIG. 9 is a cross-sectional view schematically showing an example of the organic iodine trapping device according to the present invention.
In FIG. 9, a liquid container containing a non-volatile liquid that can decompose organic iodine is installed in a dry well in the reactor containment vessel, and the non-volatile liquid is heated by the heat in the reactor containment vessel. Figure 1 shows the collection device used.

As shown in FIG. 9, a collection device 900 according to this embodiment is incorporated in the containment vessel 10 and the filter vent device 20, like the collection device 100 described above. The collection device 900 includes a liquid container 1, upstream vent pipes (2c, 2d, 2e), an isolation valve 5, a filter vent container 6, a metal filter 7, a downstream vent pipe 8, and an exhaust pipe 9. , a gas injection device 15 , a gas injection pipe 16 , and a liquid injection pipe 17 .

The collection device 900 according to this embodiment differs from the collection device 100 described above in that the gas injection device 15 is connected to the liquid container 1 and the upstream vent pipes (2c, 2d, 2e) are It is in the related piping system. Other device configurations of the collection device 900 are substantially the same as those of the collection device 100 described above.

In the collection device 900 , the dry well 11 is connected to a dry vent pipe 2 c for venting the gas inside the dry well 11 . An isolation valve 5 is provided in the dry vent pipe 2c. A wet vent pipe 2 d for venting the gas inside the wet well 12 is also connected to the wet well 12 . An isolation valve 5 is provided in the wet vent pipe 2d.

The dry vent pipe 2 c and the wet vent pipe 2 d join together with an inlet pipe 2 e connected downstream, and the other end of the inlet pipe 2 e is connected to the filter vent container 6 . The upstream vent pipes (2c, 2d, 2e) are pipes for venting the gas (fluid) in the reactor containment vessel 10, and the gas (fluid) containing organic iodine is injected into the filter vent vessel 6. It is used for introducing into the non-volatile liquid L1 that has been added.

A liquid container 1 is installed in a dry well 11 of a nuclear reactor containment vessel 10 . A gas injection device 15 is connected to the inlet side of the liquid container 1 via a gas injection pipe 16 . The gas injection device 15 is installed outside the reactor containment vessel 10 . The outlet of the gas injection pipe 16 is open to the upper part inside the liquid container 1 .

A liquid injection pipe 17 is connected to the outlet side of the liquid container 1 . The inlet of the liquid injection pipe 17 is open at the bottom inside the liquid container 1 . Also, the other end of the liquid injection pipe 17 is connected to the filter vent container 6 . The outlet of the liquid injection pipe 17 is open to the liquid phase inside the filter vent container 6 . The liquid injection pipe 17 is used to inject the non-volatile liquid L1 prepared in the liquid container 1 into the filter vent container 6 . An isolation valve 5 is provided in the liquid injection pipe 17 .

The gas injection device 15 is a device for injecting pressurized gas into the liquid container 1 . A gas injection line 16 is used to deliver pressurized gas from the gas injection device 15 to the liquid container 1 . By injecting the pressurized gas into the liquid container 1 , the nonvolatile liquid L<b>1 prepared in the liquid container 1 can be forcibly injected into the filter vent container 6 .

Examples of the injected gas include inert gases such as nitrogen gas and argon gas, and dry air. As the gas to be injected, it is preferable to use an inert gas from the viewpoint of avoiding oxidation degradation and hydrolysis of the nonvolatile liquid L1.

Next, a method for collecting organic iodine using the collecting device 900 will be specifically described.

In the collection device 900, the non-volatile liquid L1 contained in the liquid container 1 is heated by the heat in the dry well 11 of the reactor containment vessel 10, and the inside of the dry well 11 of the reactor containment vessel 10 and the wet well 12 are heated. At least one gas (fluid) containing organic iodine is passed through the heated nonvolatile liquid L1, and the organic iodine contained in the gas is decomposed into the nonvolatile liquid L1 and collected. The non-volatile liquid L1 is preheated in the liquid container 1 and then transferred to the filter vent container 6 where the organic iodine is decomposed.

When high-temperature, high-pressure steam (gas) is released into the reactor containment vessel 10 in the event of a nuclear reactor accident, the temperature and pressure within the reactor containment vessel 10 rise. A liquid container 1 is installed in a dry well 11 inside a nuclear reactor containment vessel 10 . Therefore, the nonvolatile liquid L1 prepared in the liquid container 1 is heated by the heat inside the dry well 11 .

When the pressure inside the containment vessel 10 becomes high and it is determined that the drywell 11 or the wetwell 12 needs to be vented, the isolation valve 5 of the liquid injection pipe 17 is opened. In addition, the gas injection device 15 starts pumping the gas. When the isolation valve 5 of the liquid injection pipe 17 is opened, the nonvolatile liquid L1 prepared in the liquid container 1 is pushed by the gas injected from the gas injection device 15, and pressurized by the gas injection device 15. is sent to the filter vent container 6 through the liquid injection pipe 17 at a pressure of .

Further, when it is determined that the dry well 11 or the wet well 12 needs to be vented in the event of a nuclear reactor accident, at least one of the isolation valve 5 of the dry vent pipe 2c and the isolation valve 5 of the wet vent pipe 2d is opened. be done. These isolation valves 5 may be opened simultaneously with the isolation valves 5 of the liquid injection pipe 17 or after the isolation valves 5 of the liquid injection pipe 17 are opened. When the isolation valve 5 is opened, the high-temperature/high-pressure gas in the drywell 11 and the high-temperature/high-pressure gas in the wetwell 12 pass through the upstream side vent pipes (2c, 2d, 2e) and enter the filter vent container. sent to 6.

In the filter vent container 6, radioactive substances contained in the vented gas are collected by the nonvolatile liquid L1, the scrubbing water L2, and the metal filter 7, similarly to the collection device 100 described above.

In FIG. 9, only one system is provided as a system constituted by the liquid container 1, the gas injection device 15, the gas injection pipe 16, and the liquid injection pipe 17. Such a system is It is also possible to have more than one. For example, some of the systems may be used when a nuclear reactor accident occurs, and the remaining systems may be used when the temperature in the filter vent vessel 6 tends to drop and the accident is resolved.

According to the collection apparatus 900 and the collection method described above, the liquid container 1 is installed in the dry well 11 inside the reactor containment vessel 10, and the non-volatile liquid L1 is stored in the dry well 11 inside the reactor containment vessel 10. , the reaction rate between the nonvolatile liquid L1 and the organic iodine during venting can be increased. Since the nonvolatile liquid L1 is preheated before coming into contact with a large amount of organic iodine, the collection efficiency can be increased over a wide period of time including the initial stage of venting. Therefore, it is possible to provide an apparatus and method capable of efficiently collecting organic iodine in the containment vessel.

In addition, according to the collection device 900 and the collection method described above, the gas in the reactor containment vessel 10 does not pass through the liquid vessel 1, but passes through only the upstream side vent pipes (2c, 2d, 2e) and passes through the filter vent. Since it is sent to the container 6, it is possible to avoid a large flow resistance on the vented gas. In addition, since the gas injection device 15 is provided, it is possible to forcibly inject the nonvolatile liquid L1 into the filter vent vessel 6 without using the pressure difference between the inside and outside of the containment vessel 10. The degree of freedom of the head of the nonvolatile liquid L1 can be increased.

FIG. 10 is a cross-sectional view schematically showing an example of the organic iodine trapping device according to the present invention.
In FIG. 10, a liquid container containing a non-volatile liquid that can decompose organic iodine is installed outside the reactor containment vessel, and the non-volatile liquid is heated by the reaction heat of the fluid in the reactor containment vessel. Figure 1 shows the collection device used.

As shown in FIG. 10 , a collection device 1000 according to this embodiment is incorporated in a filter vent device 20 . The collection device 1000 includes upstream vent pipes (2c, 2d, 2e), an isolation valve 5, a filter vent container 6, a metal filter 7, and a downstream vent pipe 8, similar to the collection device 800 described above. , an exhaust stack 9 and a reactor 14 .

The collection device 1000 according to this embodiment differs from the collection device 800 described above in that the liquid container 1 is not provided, the non-volatile liquid L1 is prepared in the filter vent container 6, and the vent pipe (2c , 2d and 2e) is equipped with a reactor 14 for generating heat of reaction. Other device configurations of the collection device 1000 are substantially the same as those of the collection device 800 described above.

In the trapping device 1000 , the dry well 11 is connected to a dry vent pipe 2 c for venting the gas inside the dry well 11 . An isolation valve 5 is provided in the dry vent pipe 2c. A wet vent pipe 2 d for venting the gas inside the wet well 12 is also connected to the wet well 12 . An isolation valve 5 is provided in the wet vent pipe 2d.

The dry vent pipe 2 c and the wet vent pipe 2 d join together with an inlet pipe 2 e connected downstream, and the other end of the inlet pipe 2 e is connected to the filter vent container 6 . The upstream vent pipes (2c, 2d, 2e) are pipes for venting the gas (fluid) in the reactor containment vessel 10, and the gas (fluid) containing organic iodine is prepared in the filter vent container 6. It is used for introducing into the non-volatile liquid L1 that has been added.

A filter vent container 6 is provided with a non-volatile liquid L1 and scrubbing water L2. A liquid having a lower specific gravity than the scrubbing water L2 is preferably used as the nonvolatile liquid L1. With such a liquid, the non-volatile liquid L1 phase-separates from the scrubbing water L2 to form an upper layer. It can be reliably blocked by L1. A scrubber nozzle (not shown) formed of, for example, a multiple venturi nozzle or the like can be attached to the outlet of the inlet pipe 2e.

In the collection device 1000, as the reactor 14, an in-line device is connected in the middle of the inlet pipe 2e. However, as long as the reactor 14 is of the in-line type, the arrangement, number of connections, shape, reaction method, etc. are not particularly limited. The non-volatile liquid L1 placed in the filter vent container 6 may be heated using any of heat transfer from the reactor 14, heat transfer from the gas heated by the exothermic reaction in the reactor 14, or the like.

As the in-line reactor 14, similar to the collection device 800, a reactor in which a bulk reaction material is filled in a cylindrical container, or a cartridge in which a reaction material is filled in a cylindrical container is used. A built-in reactor, a reactor in which reaction materials formed in a cylindrical container are laminated and arranged, and the like can be used. A plurality of in-line type reactors 14 can be arranged in parallel and attached to the filter vent container 6 . It can also be arranged at a position in contact with the liquid phase portion in the filter vent container 6 or at a position submerged in the liquid phase portion.

Next, a method for collecting organic iodine using the collecting device 1000 will be specifically described.

In the collection device 1000, the non-volatile liquid L1 placed in the filter vent container 6 is heated by the reaction heat of the fluid in the reactor containment vessel 10, and the inside of the dry well 11 and the wet well 12 of the reactor containment vessel 10 is heated. At least one gas (fluid) containing organic iodine is passed through the heated nonvolatile liquid L1, and the organic iodine contained in the gas is decomposed into the nonvolatile liquid L1 and collected. The nonvolatile liquid L1 decomposes the organic iodine while being heated within the filter vent container 6 .

When high-temperature, high-pressure steam (gas) is released into the reactor containment vessel 10 in the event of a nuclear reactor accident, the temperature and pressure within the reactor containment vessel 10 rise. When the temperature of the core becomes high, the coolant water reacts with the zirconium of the fuel rod cladding, and a large amount of hydrogen is generated.

When the pressure in the containment vessel 10 becomes high and it is determined that the dry well 11 or the wet well 12 needs to be vented, the isolation valve 5 of the dry vent pipe 2c and the isolation valve 5 of the wet vent pipe 2d are opened. is released. When the isolation valve 5 is opened, the gas containing hydrogen and water vapor in the dry well 11 and the gas containing hydrogen and water vapor in the wet well 12 pass through the upstream vent pipes (2c, 2d, 2e) and react. It flows into vessel 14 . Since hydrogen or steam causes an exothermic reaction when it comes into contact with the predetermined reactants filled in the reactor 14 , the gas flowing into the reactor 14 becomes hotter and flows into the filter vent container 6 . The non-volatile liquid L1 provided in the filter vent container 6 is further heated by such gas and starts to react with the organic iodine in the gas.

In the filter vent container 6, the organic iodine contained in the vented gas reacts with the nonvolatile liquid L1 and is decomposed into iodine ions and organic matter. In addition, dissociated iodine ions, aerosols contained in the vented gas, inorganic iodine, and the like are dissolved and aggregated in the nonvolatile liquid L1 and the scrubbing water L2 and collected. The aerosol released into the gas phase without being collected in the liquid phase is collected by the metal filter 7 . After that, the gas from which the radioactive substances have been removed is released into the environment through the exhaust stack 9 .

According to the collection device 1000 and the collection method described above, the nonvolatile liquid L1 is heated by the reaction heat of the fluid in the reactor containment vessel 10, so that the reaction between the nonvolatile liquid L1 and the organic iodine during venting speed can be increased. The non-volatile liquid L1 can be preheated by reaction heat before coming into contact with a large amount of organic iodine. Since it can be heated to a high temperature, the collection efficiency can be increased over a wide period of time including the initial stage of venting. Therefore, it is possible to provide an apparatus and method capable of efficiently collecting organic iodine in the containment vessel.

In addition, according to the collection apparatus 1000 and the collection method described above, since the reactor 14 that generates reaction heat is provided in the middle of the inlet pipe 2e, substances in the reactor containment vessel 10 that generate exothermic reactions are removed from the reactor containment vessel. A pressure difference across 10 allows it to flow into reactor 14 . Since there is no need to install a blower or the like for sending gas, high collection efficiency can be obtained even when power is lost. Moreover, since the liquid container 1 is not required, the reaction rate between the nonvolatile liquid L1 and the organic iodine can be increased without providing an installation place for the liquid container 1 inside or outside the containment vessel 10 .

FIG. 11 is a cross-sectional view schematically showing an example of the organic iodine trapping device according to the present invention.
In FIG. 11, a liquid container containing a non-volatile liquid that can decompose organic iodine is installed in a dry well in the reactor containment vessel, and the non-volatile liquid is heated by the heat in the reactor containment vessel. Figure 1 shows the collection device used.

As shown in FIG. 11, a collection device 1100 according to this embodiment is incorporated in the reactor containment vessel 10 and the filter vent device 20, like the collection device 200 described above. The collection device 1100 includes a liquid container 1, upstream vent pipes (2a, 2b), a pressure release valve 4, an isolation valve 5, a filter vent container 6, a metal filter 7, and a downstream vent pipe 8. , and an exhaust stack 9 .

A collection device 1100 according to this embodiment differs from the collection device 200 described above in that it includes a heater 18 installed around the liquid container 1 and an emergency power supply 19 connected to the heater 18. This is the point. Other device configurations of the collection device 1100 are substantially the same as those of the collection device 200 described above.

The heater 18 is a device that generates heat by being driven by the emergency power supply 19 and is provided to further heat the non-volatile liquid L1 heated by the heat in the containment vessel 10 . The output of the heater 18 may be controlled to be constant or variably controlled. The heater 18 can be controlled, for example, so that the nonvolatile liquid L1 is kept at a predetermined temperature or higher.

The heater 18 may be a red heat radiant heater such as a halogen heater, a panel heater such as a ceramic heater or quartz heater, a liquid-filled radiator heater such as an oil heater, a fan heater such as an electric fan heater, an air conditioner, a duct heater, or the like. Various heating devices can be used, such as convection heaters.

In the collection device 1100 , as the heater 18 , an indoor installation type device is arranged so as to surround the side surface of the liquid container 1 . However, as long as the heater 18 is of the indoor installation type, the arrangement, number of installations, shape, heat generation method, etc. are not particularly limited. The non-volatile liquid L1 contained in the liquid container 1 may be heated using any of heat conduction from the heater 18 to the liquid container 1, heat transfer from the gas heated by the heater 18 to the liquid container 1, and the like. .

The emergency power supply 19 is a power supply that can operate even in the event of a nuclear reactor accident, and is used to supply power to the heater 18 in the event of power failure or the like. Various power sources such as a diesel generator, a gas turbine generator, and a storage battery can be used as the emergency power source 19 . The emergency power supply 19 may be a stationary power supply that is always connected to the heater 18, or a mobile power supply such as a power supply car that is connected in an emergency.

Next, a method for collecting organic iodine using the collecting device 1100 will be specifically described.

In the collection device 1100, the nonvolatile liquid L1 placed in the liquid container 1 is heated by the heat in the dry well 11 of the nuclear reactor containment vessel 10 and the heat generated by the heater 18, and the The gas (fluid) containing organic iodine in the dry well 11 is passed through the heated nonvolatile liquid L1, and the organic iodine contained in the gas is decomposed into the nonvolatile liquid L1 and collected. The nonvolatile liquid L1 decomposes the organic iodine while being heated within the liquid container 1 .

When high-temperature, high-pressure steam (gas) is released into the reactor containment vessel 10 in the event of a nuclear reactor accident, the temperature and pressure within the reactor containment vessel 10 rise. A liquid container 1 is installed in a dry well 11 inside a nuclear reactor containment vessel 10 . Therefore, the nonvolatile liquid L1 prepared in the liquid container 1 is heated by the heat inside the dry well 11 .

In the event of a nuclear reactor accident, high-temperature, high-pressure gas is released into the containment vessel 10, and when the pressure inside the dry well 11 exceeds a set pressure, the pressure release valve 4 opens. When the pressure relief valve 4 opens, the high-temperature, high-pressure gas in the drywell 11 flows into the liquid container 1 through the introduction pipe 2a. The nonvolatile liquid L1 prepared in the liquid container 1 is further heated by contact with the inflowing gas and starts to react with the organic iodine in the gas.

When the pressure inside the containment vessel 10 becomes high and it is determined that the dry well 11 needs to be vented, the heater 18 is activated. The heater 18 may be started at the same time as the pressure release valve 4 is opened, may be started before the pressure release valve 4 is opened, or may be started after the pressure release valve 4 is opened. . When the heater 18 is activated, the nonvolatile liquid L1 prepared in the liquid container 1 is further heated to a temperature higher than the temperature inside the dry well 11 .

In the liquid container 1, the organic iodine contained in the vented gas reacts with the nonvolatile liquid L1 and decomposes into iodine ions and organic substances. In addition, dissociated iodine ions, aerosols contained in the vented gas, inorganic iodine, etc. are dissolved in the nonvolatile liquid L1 and collected. Heating of the non-volatile liquid L1 by the heater 18 may be performed continuously or intermittently while the vented gas flows into the liquid container 1 .

Further, when the pressure inside the containment vessel 10 becomes high and it is determined that the dry well 11 and the liquid container 1 need to be vented, the isolation valve 5 is opened. The isolation valve 5 may be opened at the same time as the heater 18 is activated, or may be opened after the heater 18 is activated. When the isolation valve 5 is opened, the radioactive substances released into the gas phase without being captured in the liquid phase in the liquid container 1 are sent to the filter vent container 6 through the discharge pipe 2b.

In the filter vent container 6, radioactive substances remaining in the vented gas are dissolved and aggregated in the scrubbing water L2 and collected. The aerosol released into the gas phase without being collected in the liquid phase is collected by the metal filter 7 . After that, the gas from which the radioactive substances have been removed is released into the environment through the exhaust stack 9 .

According to the collection device 1100 and the collection method described above, the liquid container 1 is installed in the dry well 11 inside the nuclear reactor containment vessel 10, and the nonvolatile liquid L1 is stored in the dry well 11 inside the nuclear reactor containment vessel 10. and the heater 18, the reaction rate between the nonvolatile liquid L1 and the organic iodine during venting can be increased. Since the non-volatile liquid L1 is preheated before contact with a large amount of organic iodine and heated during the reaction, the collection efficiency can be increased over a wide period of time including the initial stage of venting. Therefore, it is possible to provide an apparatus and method capable of efficiently collecting organic iodine in the containment vessel.

Further, according to the collection device 1100 and the collection method described above, since the heater 18 connected to the emergency power supply 19 is provided around the liquid vessel 1, even if the temperature inside the reactor containment vessel 10 is not sufficiently high, The nonvolatile liquid L1 can be reliably preheated to a temperature at which a high reaction rate is obtained. The heater 18 can heat the non-volatile liquid L1 even when the power is lost or when the temperature inside the reactor containment vessel 10 is reduced after an accident, so the collection efficiency can be maintained over a wider period of time. can be maintained.

FIG. 12 is a cross-sectional view schematically showing an example of the organic iodine trapping device according to the present invention.
In FIG. 12, a liquid container containing a non-volatile liquid capable of decomposing organic iodine is installed outside the containment vessel, and the non-volatile liquid is heated by the heat inside the containment vessel. shows a collection device.

As shown in FIG. 12, a collection device 1200 according to this embodiment is incorporated in the reactor containment vessel 10 and the filter vent device 20, like the collection device 300 described above. The collection device 1200 includes a liquid container 1, an upstream vent pipe (introduction pipe) 2f, an isolation valve 5, a filter vent container 6, a metal filter 7, a downstream vent pipe 8, an exhaust pipe 9, A circulation pipe 13 is provided.

A collection device 1200 according to this embodiment differs from the collection device 300 described above in that the liquid container 1 is not provided and the non-volatile liquid L1 is prepared in the filter vent container 6 . Other device configurations of the collection device 1200 are substantially the same as those of the collection device 300 described above.

In the collection device 1200 , the dry well 11 is connected to an upstream vent pipe 2 f for venting the gas inside the dry well 11 . The other end of the upstream vent pipe 2 f is connected to the filter vent container 6 . An outlet of the upstream side vent pipe 2 f opens to the liquid phase portion in the filter vent container 6 .

The upstream vent pipe 2f is used to introduce the gas (fluid) containing organic iodine in the reactor containment vessel 10 into the nonvolatile liquid L1. An isolation valve 5 is provided in the upstream vent pipe 2f.

A non-volatile liquid L1 is prepared in the filter vent container 6 . A scrubber nozzle (not shown) formed of, for example, a multiple venturi nozzle or the like can be attached to the outlet of the upstream vent pipe 2f. A baffle may also be provided to resist the high-temperature, high-pressure gas ejected into the liquid.

The circulation pipe 13 forms a closed ring flow path from the filter vent vessel 6 through the dry well 11 of the reactor containment vessel 10 and back to the filter vent vessel 6 in the same manner as the liquid vessel 1 of the collection device 300 described above. are doing. One end of the circulation pipe 13 is connected to the lower portion of the filter vent container 6, and the other end is connected to the upper side thereof. An intermediate portion of the circulation pipe 13 is located inside the drywell 11, and the pipe line is laid vertically along the vertical direction.

Next, a method for collecting organic iodine using the collecting device 1200 will be specifically described.

In the collection device 1200, the nonvolatile liquid L1 placed in the filter vent container 6 is heated by the heat in the dry well 11 of the reactor containment vessel 10, and the organic iodine in the dry well 11 of the reactor containment vessel 10 is removed. The contained gas (fluid) is passed through the heated nonvolatile liquid L1, and the organic iodine contained in the gas is decomposed into the nonvolatile liquid L1 and collected. The nonvolatile liquid L1 decomposes the organic iodine while being heated within the filter vent container 6 .

When high-temperature, high-pressure steam (gas) is released into the reactor containment vessel 10 in the event of a nuclear reactor accident, the temperature and pressure within the reactor containment vessel 10 rise. Although the liquid container 1 is installed outside the reactor containment vessel 10, the non-volatile liquid L1 in the circulation pipe 13 passing through the reactor containment vessel 10 is heated. Therefore, the nonvolatile liquid L1 is heated by the heat in the reactor containment vessel 10 while naturally circulating through the circulation pipe 13 between the liquid vessel 1 and the reactor containment vessel 10 .

When the pressure inside the containment vessel 10 becomes high and it is determined that the dry well 11 needs to be vented, the isolation valve 5 is opened. When the isolation valve 5 is opened, the high-temperature, high-pressure gas in the drywell 11 flows into the filter vent container 6 through the upstream vent pipe 2f. The non-volatile liquid L1 provided in the filter vent container 6 is further heated by contact with the incoming gas and begins to react with the organic iodine in the gas.

In the filter vent container 6, the organic iodine contained in the vented gas reacts with the nonvolatile liquid L1 and is decomposed into iodine ions and organic matter. In addition, dissociated iodine ions, aerosols contained in the vented gas, inorganic iodine, and the like are dissolved and aggregated in the nonvolatile liquid L1 and collected. The aerosol released into the gas phase without being collected in the liquid phase is collected by the metal filter 7 . After that, the gas from which the radioactive substances have been removed is released into the environment through the exhaust stack 9 .

According to the collection device 1200 and the collection method described above, the liquid container 1 is installed outside the containment vessel 10, but the non-volatile liquid L1 is Since the liquid container 1 is heated, the reaction rate between the nonvolatile liquid L1 and the organic iodine during venting can be increased without providing an installation location for the liquid container 1 in the reactor containment vessel 10 . Since the non-volatile liquid L1 is preheated before contact with a large amount of organic iodine and heated during the reaction, the collection efficiency can be increased over a wide period of time including the initial stage of venting. Therefore, it is possible to provide an apparatus and method capable of efficiently collecting organic iodine in the containment vessel.

In addition, according to the collection device 1200 and the collection method described above, the nonvolatile liquid L1 in the filter vent container 6 is entirely heated by natural circulation. High collection efficiency can be obtained even at times. In addition, since the liquid is agitated by natural circulation, the nonvolatile liquid L1 and the organic iodine can be efficiently reacted.

Although the embodiments of the organic iodine collection device and the organic iodine collection method according to the present invention have been described above, the present invention is not limited to the above-described embodiments and does not depart from the technical scope. As long as various modifications are included. For example, the above embodiments are not necessarily limited to having all the configurations described. Also, it is possible to replace part of the configuration of an embodiment with another configuration, or add another configuration to the configuration of a certain embodiment. Moreover, it is also possible to add another configuration, delete a configuration, or replace a part of the configuration of a certain embodiment.

For example, each collection device and collection method described above may be applied to either a dry vent or a wet vent. In the collection devices 100, 200, 800, 900 and 1100 described above, the system of the liquid container 1 and the discharge piping can be moved to the wet well 12 side to configure the device. Also, the collection devices 200 , 700 , 800 , 1100 , 1200 described above can be applied to the vents of the wet well 12 .

Further, in each collection device described above, a plurality of types of mechanisms can be incorporated in one liquid container 1 or filter vent container 6 . For example, liquid container 1 with circulation pipe 13 of collection devices 300 and 500, filter vent container 6 with circulation pipe 13 of collection device 1200, indoor reactor 14 of collection device 700, collection device 800 At least one or more of the in-line reactor 14 , the gas injection device 15 of the collection device 900 , and the heater 18 of the collection device 1100 may be incorporated into one liquid container 1 .

Moreover, in each of the collection devices described above, it is also possible to provide a plurality of systems of the liquid container 1, the introduction pipe, and the discharge pipe. A plurality of series may be configured to have the same mechanism, or may be configured to have different mechanisms.

For example, a first liquid container 1 having an indoor-type reactor 14 and a gas injection device 15 and a second liquid container 1 having an in-line reactor 14 and a heater 18 are placed in a dry well 11. It can also be installed. According to the second liquid container 1, it is possible to use the preheated nonvolatile liquid L1 while compensating for the lack of reaction heat with the heater . Further, according to the first liquid container 1, the non-volatile liquid L1 preheated using reaction heat can be injected by the gas injection device 15 at the required time.

Alternatively, for example, the first liquid container 1 having the heater 18 and the second liquid container 1 having the indoor reactor 14 and the in-line reactor 14 may be installed in the drywell 11. can. According to the second liquid container 1, it is possible to preheat the non-volatile liquid L1 by making maximum use of the heat of reaction. Further, according to the first liquid container 1, the heater 18 can be used to preheat the nonvolatile liquid L1 even in a situation where the reaction heat is insufficient.

Further, for example, the liquid container 1 with the circulation pipe 13 of the collection device 500 may be provided with the heater 18 and the in-line reactor 14 . According to such a liquid container 1, the heat exchange with the dry well 11, the reaction heat of hydrogen and water vapor in the wet well 12, and the heat of the heater 18 compensate for each other's heat deficiencies, thereby stably supplying the nonvolatile liquid L1. can be preheated.

Also, for example, the filter vent vessel 6 with the circulation pipe 13 of the collection device 1200 may be provided with a heater 18 and an in-line reactor 14 . According to such a filter vent container 6, the heat exchange with the dry well 11, the reaction heat of hydrogen and water vapor in the dry well 11, and the heat of the heater 18 compensate for each other's lack of heat, and stably produce a nonvolatile liquid. L1 can be preheated.

Further, in each of the collecting devices and collecting methods described above, in addition to the nonvolatile liquid L1 and the scrubbing water L2, other ionic liquids, surfactant solutions, and the like may be used in combination. Moreover, in each of the collection devices described above, in addition to the illustrated pipes and equipment, other pipes and equipment may be provided. For example, each collection device may be provided with a dry well vent bypass pipe that does not pass through the liquid container 1, a wet well vent bypass pipe that does not pass through the liquid container 1, or the like. Also, the circulation pipe 13 may be passed through the dry well 11, the wet well 12, or both of them.

In addition, in each collection device and collection method described above, the type of the nuclear reactor is not particularly limited. Various types of nuclear reactors such as Boiling Water Reactor (BWR), Advanced Boiling Water Reactor (ABWR), Pressurized Water Reactor (PWR), etc. can be applied to Ionic liquids and the like that can be used as the nonvolatile liquid L1 have been put into practical use for general industries. An ionic liquid or the like contaminated with a radioactive substance can be treated and regenerated by, for example, the method described in Japanese Patent Publication No. 2003-507185.

1 liquid container 2a upstream vent pipe (introduction pipe)
2b Upstream vent pipe (exhaust pipe)
4 Pressure release valve 5 Isolation valve 6 Filter vent container 7 Metal filter 8 Downstream vent pipe 9 Exhaust stack 10 Reactor containment vessel 11 Dry well 12 Wet well 13 Circulation pipe 14 Reactor 15 Gas injection device 16 Gas injection pipe 17 Liquid injection Piping 18 Heater 19 Emergency power supply 20 Filter vent device L1 Non-volatile liquid L2 Scrubbing water 100 Collection device 200 Collection device 300 Collection device 400 Collection device 500 Collection device 600 Collection device 700 Collection device 800 Collection device 900 collection device 1000 collection device 1100 collection device 1200 collection device

Claims (15)

An organic iodine collector for collecting organic iodine in a nuclear reactor containment vessel,
a liquid container containing a non-volatile liquid capable of decomposing organic iodine;
an introduction pipe for introducing a fluid containing organic iodine in the reactor containment vessel into the nonvolatile liquid,
The non-volatile liquid is heated within the reactor containment prior to contact with the organic iodine by heat within the reactor containment or prior to contact with the organic iodine. Since it was previously circulated into the reactor containment vessel and heated, or by the heat of reaction between the fluid in the reactor containment vessel and the reactant that reacts with the material released into the reactor containment vessel, An organic iodine collector heated prior to contact with said organic iodine and then passed through said fluid to decompose said organic iodine. The organic iodine collection device according to claim 1,
The liquid container is installed in a dry well within the reactor containment vessel,
The non-volatile liquid is an organic iodine collector heated by heat in the reactor containment vessel. The organic iodine collection device according to claim 1,
The liquid container is installed in a wet well in the reactor containment vessel,
The non-volatile liquid is an organic iodine collector heated by heat in the reactor containment vessel. The organic iodine collection device according to claim 2 or 3,
A reactor is provided around the liquid container,
The reactor is an organic iodine trap that generates reaction heat by exothermic reaction of the fluid in the reactor containment vessel. The organic iodine collection device according to claim 2 or 3,
a gas injection device for injecting pressurized gas into the liquid container;
a filter vent vessel through which the fluid vented from the reactor containment vessel is passed;
The non-volatile liquid is heated by the heat in the reactor containment vessel and then sent to the filter vent vessel under the pressure of the pressurized gas to decompose the organic iodine in the filter vent vessel. Iodine collector. The organic iodine collection device according to claim 2 or 3,
A heater is provided around the liquid container,
The heater further heats the non-volatile liquid heated by the heat in the reactor containment vessel. The organic iodine collection device according to claim 1,
The liquid container is installed outside the reactor containment vessel,
The non-volatile liquid is an organic iodine collector heated by heat in the reactor containment vessel. The organic iodine collection device according to claim 7,
A circulation pipe returning from the liquid container to the liquid container through the reactor containment vessel,
The organic iodine collection device, wherein the non-volatile liquid is heated by the heat in the reactor containment vessel while circulating between the liquid container and the reactor containment vessel. The organic iodine collection device according to claim 1,
The liquid container is installed outside the reactor containment vessel,
The non-volatile liquid is an organic iodine collection device heated by heat of reaction of the fluid in the nuclear reactor containment vessel. The organic iodine collection device according to claim 9,
A reactor is provided in the introduction pipe,
The reactor is an organic iodine trapping device that causes an exothermic reaction of the fluid containing organic iodine to generate heat of reaction. The organic iodine collection device according to claim 1,
a discharge pipe for discharging the fluid introduced into the non-volatile liquid from the liquid container;
The outlet of the introduction pipe opens to the upper part of the liquid container,
The organic iodine collecting device, wherein the inlet of the discharge pipe opens to the bottom of the liquid container. The organic iodine collection device according to claim 1,
a discharge pipe for discharging the fluid introduced into the non-volatile liquid from the liquid container;
an outlet of the introduction pipe is open to a liquid phase portion in the liquid container,
The organic iodine collecting device, wherein the inlet of the discharge pipe is open to the gas phase portion in the liquid container. The organic iodine collection device according to claim 1,
An organic iodine collector in which an inlet of the introduction pipe opens to a dry well in the reactor containment vessel. The organic iodine collection device according to claim 1,
The inlet of the introduction pipe is an organic iodine collector that opens to a wet well in the containment vessel. An organic iodine collection method for collecting organic iodine in a nuclear reactor containment vessel,
A non-volatile liquid capable of decomposing organic iodine is heated in the reactor containment vessel prior to contact with the organic iodine by heat in the reactor containment vessel, or heated with the organic iodine Heating by circulating into the reactor containment vessel prior to contact, or heat of reaction between the fluid in the reactor containment vessel and the reactant that reacts with the substance released into the reactor containment vessel heating prior to contact with the organic iodine by
passing a fluid containing organic iodine in the reactor containment vessel through the heated nonvolatile liquid;
A method for collecting organic iodine, wherein the organic iodine is decomposed into the nonvolatile liquid and collected.

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