JP2013134204A - Condenser exhaust gas monitor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a condenser exhaust gas monitor with high reliability that can prevent corrosion due to ammonia by making ammonia gas concentration low even when ammonia gas with high concentration is included in sample gas.SOLUTION: The condenser exhaust gas monitor includes a filter 7 which passes sample gas including ammonia introduced from an exhaust pipe of a condenser through, and is uniformly filled inside with thread-like members, a cooling device 8 which cools the sample gas having been passed through the filter 7, and monitoring means 24 of measuring radioactivity concentration in the sample gas having been passed through the cooling device 8.

Description

  The present invention relates to a condenser exhaust monitor, and more particularly, to a condenser exhaust monitor that measures a radioactivity concentration in a gas flowing through an exhaust pipe of a condenser in a pressurized water reactor facility.

  The conventional condenser exhaust monitor samples and removes the sample gas from the condenser exhaust pipe, cools and dehumidifies the sample gas, and dissolves and removes the corrosive gas ammonia in the generated drain. The plastic scintillation detector as a radiation detector was protected from corrosion of ammonia gas. In addition, β-rays radiated from the gaseous radioactive material to be measured contained in the sample gas are stably detected under suitable conditions, and the detection signal pulses are counted by the measurement unit to determine the count rate, thereby providing a high alarm. By determining, leakage from the primary system to the secondary system in the steam generator is monitored (see, for example, Patent Document 1).

  Gaseous radioactive materials to be measured are radiated from fission products (Xe-133, etc.) generated in the fuel rod by the operation of the nuclear reactor, primary cooling water and impurities contained in it, or structures around the fuel rod. Condensator exhaust monitor for radioactive products (Ar-41, etc.) generated by conversion and not detected in secondary system cooling water Monitoring with.

  In addition, the plastic scintillation detector uses a large-diameter scintillator as a radiation sensor to detect β-rays of gaseous radioactive substances in the sample gas with high sensitivity, and is close to the incident surface of the plastic scintillator. The reflective film placed in a face-to-face configuration uses a Mylar sheet deposited with aluminum, and is made as thin as possible so that the β-rays to be measured are not attenuated. In order to prevent the reflective film from being distorted, a vent hole is provided through the surfaces of the film so that the plastic scintillator becomes a boundary (see, for example, Patent Document 2).

JP-A-6-242291 JP-A-58-55778

  The conventional condenser exhaust monitor has a very high concentration of ammonia in the exhaust gas in accordance with the recent shift to high pH control of the secondary cooling water. This is because part of the ammonia in the secondary cooling water is extracted by a vacuum pump and mixed into the condenser exhaust, and is exhausted from the condenser exhaust mother pipe that is the exhaust pipe of the condenser. This is because part of the exhaust from the mother pipe is introduced into the condenser exhaust monitor as sample gas.

  The conventional simple dehumidification alone does not lower the ammonia concentration to the extent that it has no effect, and ammonia is concentrated at a high concentration directly through the ventilation holes, so that corrosion becomes significant. Corrosion occurs on the aluminum deposition surface, and the reflection efficiency that reflects the fluorescent light emitted when β rays act on the plastic scintillator in the opposite direction to the photomultiplier tube toward the photomultiplier tube is short-term. As a result, there is a problem that the detector signal pulse of the radiation detector has a large peak value drift drift, and as a result, the leak detection sensitivity of the steam generator is lowered and the detection sensitivity of the plastic scintillation detector is lowered. It was.

  The present invention has been made to solve the above-described problems. Along with the high pH water management, even when a high concentration of ammonia gas is contained in the sample gas, the ammonia gas concentration is reduced. An object of the present invention is to provide a highly reliable condenser exhaust gas monitor that can prevent corrosion due to ammonia by concentration.

  The condenser exhaust monitor of the present invention allows a sample gas introduced from the exhaust pipe of the condenser to pass therethrough, and a cooling device that cools the sample gas that has passed through the filter filled with a thread-like member inside. And a monitoring means for measuring the radioactivity concentration in the sample gas that has passed through the cooling device.

  According to the present invention, even when a high concentration of ammonia gas is contained in the sample gas, the ammonia gas in the sample gas is removed with high efficiency by the filter in which the filamentary member is filled. Thus, corrosion due to ammonia in the detector for measuring the radioactivity concentration can be prevented, and a highly reliable condenser exhaust monitor that does not cause a decrease in detection sensitivity can be obtained.

It is a figure which shows the structure of the condenser exhaust monitor of Embodiment 1 of this invention. It is a figure which shows the structure of the separator used for the condenser exhaust gas monitor of Embodiment 1 of this invention. It is a figure which shows the structure of the coarse filter used for the condenser exhaust gas monitor of Embodiment 1 of this invention. It is a figure which shows the structure of the cooling device used for the condenser exhaust gas monitor of Embodiment 1 of this invention. It is a figure which shows the structure of the separator used for the condenser exhaust gas monitor of Embodiment 2 of this invention. It is a figure which shows the structure of the coarse filter used for the condenser exhaust gas monitor of Embodiment 3 of this invention. It is a figure which shows the structure of the condenser exhaust gas monitor of Embodiment 4 of this invention. It is a figure which shows the structure of the cooling device used for the condenser exhaust gas monitor of Embodiment 4 of this invention. It is a figure which shows the structure of the condenser exhaust monitor of Embodiment 5 of this invention. It is a figure which shows the structure of the cooling device used for the condenser exhaust gas monitor of Embodiment 5 of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, in each figure, the same code | symbol is attached | subjected about the part which is the same or it corresponds, and the description is not repeated.

Embodiment 1.
FIG. 1 is a diagram showing a configuration of a condenser exhaust monitor according to Embodiment 1 of the present invention. In FIG. 1, a condenser exhaust mother pipe 1 is an exhaust pipe connected to the condenser, and a gas flowing in the condenser exhaust mother pipe 1 is released into the atmosphere. The condenser exhaust monitor is a monitor that monitors the radioactivity concentration of the gas flowing in the condenser exhaust mother pipe 1.

  The condenser exhaust monitor includes a separator 5, a U-seal drainage mechanism 6, a filter 7 (hereinafter referred to as a coarse filter 7), a cooling device 8, fine filters 9 and 10, a flow meter 15, and a pressure gauge. 16, a detection device 17, a measurement device 18, and a pump 19.

  In FIG. 1, all components except the measuring device 18 are connected by piping. The intake pipe 2 to the intake valve 4 are the intake pipe 3, the exhaust valve 20 to the exhaust nozzle 22 are the exhaust pipe 21, and the other pipes are the circulation pipe 25.

  The separator 5 is connected to the condenser exhaust mother pipe 1 via the intake nozzle 2 and the intake valve 4. The separator 5 is connected to a U-seal drainage mechanism 6 and a coarse filter 7. The cooling device 8 is connected to the coarse filter 7 and the U seal drainage mechanism 6. The circulation pipe 25 exiting from the cooling device 8 is branched into two, connected to the fine filter 9 via the filter inlet valve 11, joined again to one circulation pipe 25 via the filter outlet valve 13, and the like Are connected to the fine filter 10 via the filter inlet valve 12, and are joined again to one circulation pipe 25 via the filter outlet valve 14. The circulation pipe 25 is connected to the exhaust valve 20 via a flow meter 15, a pressure gauge 16, a detection device 17, and a pump 19. The exhaust pipe 21 is connected to the condenser exhaust mother pipe 1 from the exhaust valve 20 through the exhaust nozzle 22.

  Next, functions of each component and device of the condenser exhaust monitor according to the first embodiment will be described.

  The condenser exhaust monitor sucks and samples the sample gas from the intake nozzle 2 inserted into the condenser exhaust mother pipe 1. The sample gas sampled is introduced from the intake valve 4 for shutting off the system when the sampling is stopped via the intake pipe 3.

  Since a large amount of water vapor is extracted together with air in the condenser exhaust mother pipe 1, the exhaust gas in the condenser exhaust mother pipe 1 is generated in a supersaturated state as water vapor is drained. Thus, drain is a liquid waste. On the other hand, the main component of sludge is iron rust of piping, including suspended matter. Thus, sludge is a solid waste. Since drain and sludge are secondary systems, both are usually not radioactive waste.

  The separator 5 is used to separate and remove drain and sludge from the sample gas sucked from the condenser exhaust mother pipe 1. A detailed description of the separator 5 will be described later with reference to FIG.

  The coarse filter 7 removes relatively large dust floating in the sample gas on the surface layer, and grows mist mixed in the sample gas into water droplets while proceeding to the deep layer, and the water droplets are included in the sample gas. Ammonia is dissolved into ammonia water and scattered downstream. The detailed configuration of the coarse filter 7 will be described later with reference to FIG.

  The cooling device 8 introduces and cools the sample gas together with the ammonia water scattered from the coarse filter 7, condenses the water vapor contained in the sample gas, and discharges it as a drain to the U-seal drainage mechanism 6. , 10 are discharged. The detailed configuration of the cooling device 8 will be described later with reference to FIG.

  The U-seal drainage mechanism 6 is used when discharging sludge and drain. The drain containing the sludge discharged from the separator and the drain discharged from the cooling device are discharged from the U-seal drainage mechanism 6.

  The fine filters 9 and 10 are provided as a pretreatment for measuring the radioactivity concentration in the sample gas in order to remove fine particulate matter contained in the sample gas on the upstream side of the detection device 17 to be described later. A material that removes 99% or more of particulate matter of 0.3 μm or more is used.

  Two fine filters 9 and 10 are provided in parallel so that one can be used even if the other is under maintenance. The filter inlet valves 11 and 12 and the filter outlet valves 13 and 14 are respectively provided, the filter inlet and outlet valves to be operated are opened, the filter inlet and outlet valves to be stopped are closed, and the filter can be replaced even during operation. Yes. The fine filters 9 and 10 are manufactured by sticking glass fibers to a cold chill. At this time, the fine filters 9 and 10 are used by being punched into, for example, φ50 mm and mounted on a case. The coarse filter 7 is removed on the surface layer, while the fine filters 9 and 10 remove particulate matter on the surface. After passing through the fine filters 9 and 10, the ammonia concentration is lowered to such an extent that corrosion of the scintillator aluminum does not occur.

  The flow meter 15 is provided to measure the flow rate of the sample gas from which fine particulate matter in the condenser exhaust monitor has been removed. The pressure gauge 16 is provided for measuring the pressure in the condenser exhaust monitor.

  It can be confirmed from the measurement value of the flow meter 15 that the sampling function is operating normally, and the concentration of the gaseous radioactive substance is corrected to the atmospheric pressure conversion value based on the measurement value of the pressure gauge 16.

  The detection device 17 detects β rays emitted from the gaseous radioactive substance in the sample gas with a plastic scintillation detector (not shown) and outputs a detection signal pulse.

  The measuring device 18 counts the detection signal pulses to measure the count rate, performs a high alarm determination based on the count rate, and outputs a high alarm and a count rate as a result of the determination. Therefore, the concentration of the gaseous radioactive substance is obtained based on the count rate output from the measuring device 18.

  The monitoring unit 24 includes a detection device 17 and a measurement device 18.

  The pump 19 is used for increasing the pressure of the sample gas in the pipe downstream from the pump of the condenser exhaust monitor and exhausting it.

  The sample gas discharged from the detection device 17 is exhausted from the exhaust valve 20 for shutting off the system when sampling is stopped, through the exhaust pipe 21 and from the exhaust nozzle 22 to the condenser exhaust mother pipe 1.

  FIG. 2 is a diagram showing the structure of the separator 5 used in the condenser exhaust monitor according to Embodiment 1 of the present invention. The separator 5 separates and removes the drain and sludge that flow in with the sample gas.

  In the separator 5, a boundary is formed by a packing 53 that seals both the container 51 and the lid 52, and a partition wall 54 that bisects the upper space of the container 51 is attached to the lid 52. The partition wall 54 is a plate-like member having a wide wall surface in a direction substantially perpendicular to the flow direction of the sample gas. That is, the partition wall 54 has a wall surface that changes the flow direction of the sample gas. The drain introduced together with the sample gas from the intake port 55 hits the partition wall 54 and falls along it, and is discharged from the drain port 56. The sample gas from which the drain is separated has a structure that bypasses the partition wall 54 and is discharged from the exhaust port 57. The drain discharged from the drain port 56 is introduced into the U-seal drain mechanism 6.

  Drain and sludge contained in the sample gas flowing from the condenser exhaust pipe 1 through the intake nozzle 2 can be separated from the sample gas by creating a space in the separator 5 and reducing the flow velocity. Even if the sludge is iron rust powder, it falls by gravity. The partition wall 54 is necessary in the separator 5 to reliably separate the drain and sludge from the sample gas.

  FIG. 3 is a diagram showing the structure of the coarse filter 7 according to the first embodiment of the present invention. The coarse filter 7 has a boundary formed by a container 73 and a lid 72 and a packing 73 that seals both, and a steel wool that is a thin thread-like member serving as a filter element by a lower wire mesh 74 and an upper wire mesh 75 attached to the inside of the container 71. 76 is uniformly filled and sandwiched. As a member that easily wets and does not corrode with ammonia, for example, a commercially available stainless steel member can be easily obtained. In addition, maintenance is facilitated by replacing only the surface steel wool 76 in accordance with the periodic inspection of the plant. The filter element uniformly spreads and fills the steel wool 76 in the container 71.

  A sample gas containing dust and mist is introduced from the intake port 77, and relatively large dust contained in the sample gas is removed from the surface layer of the steel wool 76. Then, mist in the sample gas grows on the surface of the steel wool 76 while passing through the layer of the steel wool 76 to generate a water film. When ammonia gas is dissolved and taken into the water film and grows into water droplets of ammonia water, the ammonia water is scattered and discharged from the exhaust port 78 together with the sample gas.

  FIG. 4 is a diagram showing the structure of the cooling device 8 according to the first embodiment of the present invention. The cooling device 8 includes an evaporator 81 and a refrigerator unit 82. In the evaporator 81, sample gas is introduced into the container 811 from the intake port 812. The cooling fins 813 inside the sample container 811 have a structure in which a passage time is formed so that the sample gas sequentially changes its direction between the bottom and the ceiling, thereby extending the residence time of the sample gas. The sample gas comes into contact with the cooling fins 813 and is cooled by heat exchange, whereby water vapor contained in the sample gas is condensed, and drain is generated together with the introduced ammonia water droplets. The refrigerator unit 82 supplies the refrigerant to the refrigerant pipe 814 and cools the cooling fins 813. The cooled sample gas is discharged from the exhaust port 815, and the generated drain is discharged from the drain port 816. The drain discharged from the drain port 816 is gathered together with the drain discharged from the drain port 56 of the separator 5 in the U-seal drain mechanism 6 and discharged outside the system.

  In the above-described embodiment, an example in which the steel wool 76 is used as an example of the thread-like member has been described. However, in addition to the steel wool 76, a thin thread-like member that can be replaced may be used. The same applies to the following embodiments. As an alternative material, a thread-like member made of a material having a hydrophilic surface that is easily wetted and hardly deteriorated by ammonia is used, and any material such as a ceramic material, a polymer material, or a metal material can be used as long as this condition is satisfied. It may be.

  As described above, according to the first embodiment, most of ammonia is removed as ammonia water by the water film having a large surface area generated in the filled steel wool 76, and the remaining ammonia is sample gas by the cooling device 8. Since the water is cooled and taken into the condensed water for removal, the ammonia concentration can be reduced to the level of the general environment. A vacuum state is maintained in the condenser (not shown) during plant operation. The ammonia concentration in the condenser exhaust mother pipe 1 has a large range of several hundred ppm to 20000 ppm. There is a possibility that a problem may occur when the ammonia concentration in the condenser exhaust mother pipe 1 exceeds about 2000 ppm, since the ammonia concentration is processed at a low concentration in this embodiment. There is no problem. Furthermore, since corrosion deterioration of the aluminum vapor deposition surface due to ammonia in the plastic scintillation detector of the detection device 17 can be prevented, the condenser exhaust having high sensitivity, high reliability, and good maintainability without being affected by the recent high pH water management. A gas monitor is obtained.

  Further, according to the first embodiment, since the separator 5 is provided in front of the coarse filter 7, most of the drain and sludge mixed with the sample gas can be removed, and the water of the steel wool of the coarse filter can be removed. The reduction of the membrane surface area can be suppressed, and the clogging of the coarse filter due to the sludge can be suppressed. Therefore, the frequency of replacing the steel wool 76 of the coarse filter 7 can be reduced, and maintenance is facilitated.

  Further, since the separator 5 includes a partition wall 54 having a wall surface that changes the flow direction of the sample gas, the separator 5 can drain and sludge from the sample gas more efficiently than the container 51 without the partition wall 54. Can be separated. Therefore, the separator 5 can reduce the space of the container 51 and can reduce the size of the separator 5.

  There is a method in which a strainer having a mesh filter is provided in front of the cooling device 8, and dust in the sample gas is removed by the strainer. However, with this strainer method, if the filter mesh is large, the sludge separation ability is low, and dust cannot be removed sufficiently. Conversely, if the mesh is small, the dust is quickly clogged and the filter is frequently replaced. There is a problem that must be done. In the method using the strainer, it takes time to disassemble and clean the strainer and the cooling device 8 in order to remove the dust adhering to the strainer and to remove the dust adhering in the cooling device 8 at the subsequent stage. descend. Further, since the strainer cannot secure a large surface area, the ammonia cannot be melted into water vapor and grown into water droplets, and the ammonia concentration cannot be lowered sufficiently.

  Further, according to the first embodiment, by removing relatively large dust contained in the sample gas at the surface layer of the steel wool 76 of the coarse filter 7, the cooling fins 813 of the cooling device 8 are protected and the thermal efficiency is deteriorated. Can be prevented. Furthermore, it is not necessary to perform large-scale disassembly and cleaning of the cooling device 8 during periodic plant inspections.

  Further, according to the first embodiment, since the coarse filter 7 is uniformly filled with the thread-like member, the coarse filter 7 efficiently separates evenly when the dust contained in the sample gas is removed by the steel wool 76. can do.

  Furthermore, the steel wool 76 may be uniformly laminated when the coarse filter 7 is uniformly filled with the thread-like member. By uniformly laminating the steel wool 76 from the upper part, dust accumulates without unevenness. Since the steel wool 76 is uniformly deteriorated from the upper layer by dust collecting on the steel wool 76 without bias, the steel wool 76 only needs to be replaced when the deterioration progresses. The replacement frequency of the wool 76 can be reduced.

Embodiment 2.
FIG. 5 is a diagram showing the structure of the separator 50 according to the second embodiment of the present invention. In the first embodiment, a structure is provided in which the partition wall 54 that bisects the upper space of the container 51 is attached to the lid 52 of the separator 5, or the partition wall 54 is not attached to the lid 52 and the intake port 55 is positioned lower than the exhaust port 57. It was set as the structure provided. In the separator 50 of the second embodiment, the lid 51 is provided with a roof 58, and the intake port 55 is arranged so that the sample gas blows down toward the roof 58. In addition, the separator 50 has an exhaust port 59 so that the sample gas is sucked and discharged from the space directly below the roof 58, and drain and sludge are collected along the roof 58 and then along the inner wall of the container 51. The structure is such that it flows down and is discharged from the drain outlet 56.

  The roof 58 has an umbrella shape with a conical shape with no bottom and a space inside. The exhaust port 59 is provided with one inlet so as to be positioned higher than the bottom of the cone, and provided with the other outlet so as to go out of the container from a position lower than the roof 58. Further, the drain port 56 is located at the center of the bottom of the container 51. In the second embodiment, the outer surface of the roof 58 functions as a wall surface that changes the flow direction of the sample gas. Further, the air inlet 55 is disposed at a position higher than the bottom of the roof 58 so as to change the flow direction of the sample gas.

  The roof 58 may have any shape as long as it covers the upper part of the exhaust port 59. Specifically, the shape may be a polygonal pyramid including a triangular pyramid in addition to the conical shape as long as the tip has an umbrella shape with an acute angle or an obtuse angle.

  As described above, according to the second embodiment, the separator 50 includes the umbrella-shaped roof 58 having a wall surface, and the exhaust port 56 is provided at a position higher than the inside and lower end of the roof 58. Drain and sludge can be separated more efficiently than in the first embodiment.

Embodiment 3.
FIG. 6 is a diagram showing the structure of the coarse filter 70 according to the third embodiment of the present invention. In the coarse filter 7 of the first embodiment, as shown in FIG. 3, the steel wool 76 is uniformly filled and sandwiched between the lower metal mesh 74 and the upper metal mesh 75 attached to the inside of the container 71. In the coarse filter 70 according to the third aspect, as shown in FIG. 6, the steel wool 76 is uniformly filled and loaded into the removable inner container 79 having a mesh structure on the upper surface and the lower surface, and the steel wool 76 is loaded with the upper metal mesh 75. The structure is to hold down.

  As described above, since the configuration of the third embodiment is adopted, the inner container 79 can be taken out of the container 71 and the steel wool 76 can be replaced, and the maintenance of the coarse filter can be facilitated.

Embodiment 4.
FIG. 7 is a diagram showing a configuration of a condenser exhaust monitor according to the fourth embodiment of the present invention. FIG. 8 shows a structure of cooling apparatus 800 according to the fourth embodiment of the present invention. In the fourth embodiment, instead of the coarse filter 7 and the cooling device 8 of the first embodiment, as shown in FIG. 7, a cooling device 800 in which they are integrated is provided.

  The cooling device 800 includes a coarse filter unit 820 and a cooling unit 810. As shown in FIG. 8, the coarse filter unit 820 forms a sample gas boundary with a container 821 formed by extending the container 811 of the cooling unit 810, a removable lid 822, and a packing 823, and the sample gas is supplied from the inlet 824. The steel wool 826 is uniformly filled between the wire mesh 825 following the space where the flow direction is changed inside the lid 822 and the cooling fin 813 of the cooling unit 810, and a part of the steel wool 826 is filled. Is in contact with the refrigerant pipe 814 of the cooling unit 810.

  As described above, according to the fourth embodiment, since the cooling device 800 including the coarse filter unit 820 and the cooling unit 810 is provided, the metabolism of the water film is accelerated, so that ammonia can be removed more efficiently. In addition, since the coarse filter unit 820 and the cooling unit 810 are integrally formed, the system is simplified, the steel wool 826 can be easily replaced from the lid 822, and it is highly reliable, has good maintainability, and has a low installation space. A condenser exhaust gas monitor can be provided.

Embodiment 5.
FIG. 9 is a diagram showing the structure of a condenser exhaust monitor according to the fifth embodiment of the present invention, and FIG. 10 is a diagram showing the structure of a cooling device 8000 according to the fifth embodiment of the present invention. As shown in FIG. 9, in the fifth embodiment, a cooling device 8000 is provided instead of the cooling device 800 of the fourth embodiment. As shown in FIG. 10, the cooling device 8000 of the fifth embodiment includes a mist separation unit 830 subsequent to the cooling unit 810, and the coarse filter unit 820, the cooling unit 810, and the mist separation unit 830 are integrally formed. Has been.

  The cooling device 8000 of the fifth embodiment includes a coarse filter unit 820, a cooling unit 810, and a mist separation unit 830 as shown in FIG.

As shown in FIG. 10, the cooling device 8000 of the present embodiment provides a sample gas boundary with a container 831 of a mist separation unit 830 formed by extending a container 811 of a cooling unit 810, a removable lid 832, and a packing 833. It is composed.
The mist separation unit 830 includes a packing 833, a direction change plate 834, a steel wool 835 that is a thread-like member, and a lid 832. The mist separation unit 830 is for separating the mist, and is attached to the rear portion of the refrigerant pipe 814 in the cooling unit 810. The cooling unit 810 is filled with steel wool 835 between the final stage of the cooling fins 813 and the direction change plate 834 that converts the direction of the sample gas in the mist separation unit 830.

  In the cooling unit 810, the condensed water containing drain generated at the final stage of the cooling fin 813 is removed by the steel wool 835, gathered and discharged from the drain port 837, and the sample gas is discharged from the exhaust port 836.

  As described above, according to the fifth embodiment, since the mist separation unit 830 is provided at the subsequent stage of the cooling unit 810, the mist scattered downstream from the cooling device 8000 can be minimized, and ammonia can be further reduced. Since the concentration can be lowered, corrosion deterioration of the aluminum vapor deposition surface due to ammonia in the plastic scintillation detector of the detection device 17 can be prevented, so that a condenser exhaust monitor with higher reliability than that of the first embodiment can be provided.

DESCRIPTION OF SYMBOLS 1 Condenser exhaust mother pipe 3 Intake piping 5,50 Separator 51 Container 54 Partition 56 Drain outlet 57 Exhaust outlet 58 Roof 59 Exhaust outlet 7,70 Coarse filter (filter)
71 Container 76 Steel wool 78 Exhaust port 79 Inner container 8,800,8000 Cooling device 811 Container 815 Exhaust port 821 Container 826 Steel wool 830 Mist separation part 831 Container 835 Steel wool 836 Exhaust port 24 Monitoring means

Claims (11)

A filter through which the sample gas introduced from the exhaust pipe of the condenser is passed and filled with a thread-like member;
A cooling device for cooling the sample gas that has passed through the filter;
A condenser exhaust monitor, comprising: monitoring means for measuring a radioactivity concentration in the sample gas that has passed through the cooling device.   2. The condenser exhaust monitor according to claim 1, further comprising a separator that separates drain and sludge from the sample gas introduced from the exhaust pipe before the filter. The separator includes an inlet for introducing a sample gas from the exhaust pipe;
A wall surface that changes the flow direction of the sample gas introduced from the inlet;
A drain outlet for drainage and sludge;
The condenser exhaust monitor according to claim 2, further comprising a container having an exhaust port for discharging the sample gas from which the drain and sludge are separated.   The condenser exhaust monitor according to claim 3, wherein the plate-like member having the wall surface is provided on an inner surface of the container, is fixed from an upper part of the container, and is provided to a position lower than the exhaust port. The separator includes an umbrella-shaped roof having the wall surface,
The condenser exhaust monitor according to claim 3, wherein the exhaust port is provided at a position inside the roof and higher than a lower end.   The condenser exhaust monitor according to any one of claims 1 to 5, wherein the filter includes an inner container having a mesh structure on an upper surface and a lower surface, and the inner container is filled with the thread-like member. .   The condenser exhaust monitor according to any one of claims 1 to 6, wherein the filter and the cooling device are integrally formed.   The condenser exhaust monitor according to any one of claims 1 to 7, wherein the filter is formed by laminating the thread-like members.   The condenser exhaust monitor according to any one of claims 1 to 8, wherein the thread-like member is steel wool.   The condenser exhaust monitor according to any one of claims 1 to 9, further comprising a mist separation unit that prevents mist from being scattered downstream of the cooling device.   The condenser exhaust monitor according to claim 10, wherein the mist separation unit is filled with the thread-like member.

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