JP6308929B2 - Ventilation and air conditioning equipment for nuclear power plants - Google Patents

Description

  The present invention relates to a ventilation air conditioner for a nuclear power plant.

  The nuclear power plant has a central control room where workers stay in order to perform operation control and monitoring. Ventilation air-conditioning equipment is connected to the central control room, taking outside air to supply to the central control room and exhausting the air in the central control room to the outside environment to keep the environment (temperature and humidity) in the central control room properly ing. In the unlikely event that a radioactive material leakage accident occurs at a nuclear power plant due to the use of ventilation air conditioning equipment, the indoor environment of the central control room is maintained and workers are prevented from being exposed to radiation. There is a need to.

  For this reason, the central control room ventilation air conditioner is equipped with a filter that removes radioactive substances contained in the outside air taken into the central control room, and in the event of an accident, the ventilation mode is switched from the normal ventilation mode to the emergency ventilation mode. The inflow of radioactive material from is restricted. An example of such a central control room ventilation facility is described in Patent Literature 1 and Patent Literature 2.

  In addition, in the emergency ventilation mode of the above ventilation air conditioning equipment, the concentration of radioactive materials in the room and the concentration of radioactive materials in the external environment are measured and compared, and the exposure of workers is controlled by controlling the amount of outside air intake and the amount of recirculated air. A method of reducing is described in Patent Document 3.

JP 9-133788 A JP-A-9-159207 JP 2010-223602 A

  The worker exposure standards for radioactive material leaks in the event of an accident at a nuclear power plant are reviewed. This review of worker exposure standards has led to the need to solve the following new issues.

  In the event of an accident at a nuclear power plant, workers stay in the central control room in the building and carry out the accident convergence work. At this time, the building is ventilated and air-conditioned in the emergency ventilation mode by the ventilation air-conditioning equipment. Specifically, in the current ventilation air-conditioning equipment, supply ducts and exhaust ducts are respectively provided in an area where a worker stays in the building (such as a central control room) and in other areas (such as machinery parts rooms) in the building. (Or a recirculation line) is provided, and air is supplied to all areas where ventilation air-conditioning is performed when outside air is taken in.

  The 1st subject in the premise which concerns arises by the whole area air supply of external air. In the unlikely event that radioactive material remains in the supplied air, the entire area may be contaminated with the radioactive material, so the first problem is that it is necessary to prevent this.

  At nuclear power plants, ventilation air conditioning equipment keeps the building at a positive pressure relative to outside air, preventing contaminated outside air from flowing in from outside the ventilation air conditioning equipment (ducts, air supply / exhaust ports, etc.). . However, in the current ventilation air-conditioning equipment configuration, in-leakage of radioactive material into the building (central control room, etc.) has been confirmed by tests, and there is concern that workers may be exposed to radioactive material flowing into the interior. .

  Therefore, the second problem is that it is necessary to reliably maintain positive pressure in the building, particularly in an area where a worker stays (such as a central control room).

  Furthermore, in nuclear power plants, there is a possibility of implementing filter venting at the time of an accident, but radioactive noble gases released at the time of filter venting cannot be removed by the currently installed filter (iodine charcoal filter).

  Therefore, the third problem is that it is necessary to protect workers from exposure even when radioactive noble gases are released.

  In view of the above, an object of the present invention is to provide a ventilation air-conditioning facility for a nuclear power plant capable of preventing the entire area from being contaminated with radioactive substances.

  Moreover, in the Example of this invention, it aims at providing the ventilation air conditioning equipment of the nuclear power plant which can maintain the area (central control room etc.) where an operator stays positively reliably. A still further object of the present invention is to provide a ventilation air conditioning facility for a nuclear power plant that can protect workers from exposure even when radioactive noble gases are released. More preferably, in the embodiment of the present invention, in order to solve the first to third problems and reduce the exposure of the worker, the area where the worker stays (such as the central control room) is isolated as a boundary. The present invention provides a ventilation and air conditioning system that reliably prevents the inflow of radioactive substances from outside by ensuring the positive pressure in the area.

  In order to solve the problems of the present invention, in the ventilation air conditioning system of the nuclear power plant of the present invention, the building is divided into an isolation request area including a central control room and other areas, and air is supplied to the building area from the outside. In order to do so, the first air supply duct in which the blower and the air supply processing device are installed, and the recirculation fan and the recirculation filter device in which the recirculation fan and the recirculation filter device are installed to exhaust air from the building and introduce air into the building again It comprises a circulation duct, an exhaust duct in which an exhaust fan is installed to exhaust air from the building, and an inter-area duct communicating between the building areas.

  According to the present invention, it is possible to prevent the spread of radioactive material contamination by isolating the “isolation request area” where the worker stays. Furthermore, in the embodiment, the building can be reliably maintained at a positive pressure. Further, in the embodiment, pressurization and supply of fresh air can be performed even when radioactive noble gas is released, and the exposure of workers can be reduced.

1 is a system diagram showing an overview of a central control room ventilation air conditioning facility of a nuclear power plant according to Embodiment 1. FIG. The system diagram which shows the outline | summary of the central control room ventilation air conditioning equipment of the nuclear power plant which concerns on Example 2. FIG. The system diagram which shows the outline | summary of the central control room ventilation air conditioning equipment of the nuclear power station which concerns on Example 3. FIG. The system diagram which shows the outline | summary of the central control room ventilation air conditioning equipment of the nuclear power plant which concerns on Example 4. FIG. The system diagram which shows the outline | summary of the central control room ventilation air conditioning equipment of the nuclear power station which concerns on Example 5. FIG. The system diagram which shows the outline | summary of the central control room ventilation air conditioning equipment of the nuclear power plant which concerns on Example 6. FIG. The system diagram which shows the outline | summary of the central control room ventilation air conditioning equipment of the nuclear power plant which concerns on Example 7. FIG. The system diagram which shows the outline | summary of the central control room ventilation air conditioning equipment of the nuclear power plant which concerns on Example 8. FIG.

  Hereinafter, embodiments according to the present invention will be described with reference to the drawings. In addition, the same code | symbol is attached | subjected to the same or similar structure, and the overlapping description is abbreviate | omitted.

  FIG. 1 is a system diagram illustrating an overview of a central control room ventilation air conditioning facility of a nuclear power plant according to a first embodiment.

  In FIG. 1, a building B of a nuclear power plant that is the target of ventilation air conditioning is divided into an isolation request area (such as a central control room) A1, another area (such as a machinery room) A2, a passage A3, and the like. The isolation request area A1 and the other area A2 are supplied with air from the air supply ducts DI1 and DI2, respectively, and finally exhausted from the exhaust duct DO provided in the other area A2 of the building B. Further, the exhaust gas taken out from the recirculation duct DR provided in the passage area A3 of the building B is used again as the air supply from the air supply ducts DI1 and DI2. Note that inter-area ducts D13 and D23 are provided between the isolation request area A1 and the passage area A3 and between the other area A2 and the passage area A3 for ventilation between the divided areas.

  Equipment for supplying air from the outside to the duct installed in the building, equipment for exhaust, and equipment for recirculation are configured as follows.

  First, as equipment for supplying air from the outside, an air supply isolation valve 7, an air supply processing device 6, and a blower 5 are installed in order from the outside air inlet 8, and an isolation request area A1 from the air supply ducts DI1 and DI2 is provided. In addition, air is supplied to the other area A2.

  In addition, as an equipment for exhaust, an exhaust fan 14, an exhaust isolation valve 15, and an exhaust port 16 are installed sequentially from an exhaust duct DO connected to the other area A2. In addition, regarding exhausting from the other area A2, hydrogen gas that can be emitted from equipment in the area A2 can be discharged to the outside.

  Further, as equipment for recirculation, a recirculation line isolation valve 12, a recirculation filter device 11, and a recirculation blower 10 are installed sequentially from the recirculation duct DR connected to the passage area A3, and the air supply processing device 6 is installed. The air supply ducts DI1 and DI2 are connected via the blower 5.

  According to the area division of FIG. 1, the isolation request area A1 including the central control room is set as the highest priority environment, and the environments of the other areas A2 and A3 in the building are secured and maintained.

  According to the first embodiment of the present invention, the facility is operated as follows during normal times and accidents.

  First, in normal time, outside air taken in through the outside air inlet 8 is processed by the air supply processing device 6, and then supplied to the isolation request area A1 and other areas A2 through the air supply ducts DI1 and DI2 by the blower 5. A part of the indoor air in the other area A2 is exhausted to the external environment through the exhaust duct DO and the exhaust fan 14. The remaining room air in the isolation request area A1 and the other area A2 passes through the inter-area ducts D13 and D23 and is supplied to the passage area A3, and returns to the supply ducts DI1 and DI2 again by the recirculation duct DR. It will be recirculated by joining the newly introduced outside air. This state is referred to as a partially outside air recirculation mode.

  On the other hand, at the time of an accident, the air supply isolation valve 7 and the exhaust isolation valve 15 are closed, the central control room ventilation air conditioning equipment is shut off from the external environment, and the entire quantity recirculation mode is set. This makes it possible to carry out ventilation air conditioning in the ventilation area without taking outside air contaminated with radioactive material into the building.

  As described above, according to the first embodiment, as a response to the first problem, the building is blocked from outside air at the time of an accident, and the entire area is prevented from being contaminated with radioactive substances by recirculating the building air. doing.

  FIG. 2 is a system diagram illustrating an overview of a central control room ventilation air conditioning facility of a nuclear power plant according to a second embodiment. In contrast to FIG. 1, a dotted line portion X1 is newly added in FIG. The configuration of the additional portion X1 further addresses the second problem.

  In the central control room ventilation air conditioning system of FIG. 2, the recirculation duct DR is measured by the differential pressure control device 20 that measures the differential pressure between the passage area A3 and the outdoor atmosphere with the differential pressure gauge 19 and adjusts so as to ensure an appropriate differential pressure. The opening of the differential pressure adjusting damper 21 installed in is controlled.

  By controlling the opening of the differential pressure adjusting damper 21, the indoor pressure is adjusted in accordance with the fluctuation of the atmospheric pressure, and the ventilation areas A1, A2, and A3 are reliably kept at a positive pressure to prevent the inflow of contaminated outside air. It is possible to reduce the exposure of workers.

  As described above, according to the second embodiment, as a response to the second problem, an area where the worker stays (such as the central control room) is positively positively adjusted by adjusting the indoor pressure according to the fluctuation of the atmospheric pressure. It is possible to maintain.

  FIG. 3 is a system diagram illustrating an overview of a central control room ventilation air conditioning facility of a nuclear power plant according to a third embodiment. In contrast to FIG. 2, a dotted line portion X2 is newly added in FIG. FIG. 3 also corresponds to the second problem due to the configuration of the additional portion X2.

  In the central control room ventilation air conditioning system of FIG. 3, an isolation valve 22 is installed in each of the air supply duct DI1 connected to the isolation request area A1 and the inter-area duct D13 connecting the isolation request area A1 to the passage area A3. is there.

  In the event of an accident, the isolation valve 22 at the doorway is closed, thereby isolating the isolation request area A1 from the external environment and reducing the exposure of workers.

  As described above, according to the third embodiment, as a countermeasure to the second problem, by closing the entrance / exit isolation valve 22 in the event of an accident, the area where the worker stays (such as the central control room) is surely positive pressure. It is possible to maintain.

  FIG. 4 is a system diagram illustrating an overview of a central control room ventilation air conditioning facility of a nuclear power plant according to a fourth embodiment. In contrast to FIG. 3, a dotted line portion X3 is newly added in FIG. Due to the configuration of the additional portion X3, FIG. 4 shows a response to a new problem that occurs accompanying the countermeasure of the third embodiment. In short, the new issue is the elimination of shortness of breath due to the isolation of areas where workers stay (such as the central control room).

  In the central control room ventilation air conditioner of FIG. 4, a local air conditioner (local cooler) 23 is installed in the isolation request area A1.

  By installing the local cooler 23, it becomes possible to appropriately manage the room temperature in the isolation request area A1, improve the comfortability of workers, and satisfy the specification requirements of the equipment used in the area A1. .

  As described above, according to the third embodiment, as a response to the new problem that occurs accompanying the countermeasure of the third embodiment, the room temperature in the isolation request area A1 is appropriately managed, thereby eliminating the stuffyness of the worker. It is a thing.

  FIG. 5 is a system diagram illustrating an overview of a central control room ventilation air conditioning facility of a nuclear power plant according to a fifth embodiment. In contrast to FIG. 4, a dotted line portion X4 is newly added in FIG. FIG. 4 also corresponds to the second problem due to the configuration of the additional portion X4.

  In the central control room ventilation air conditioning system of FIG. 5, a pressurizing duct DA provided with a pressurizing blower 25, a pressurizing filter device 26, a pressurizing isolation valve 27, and a pressurizing outside air inlet 28 is connected to the isolation request area A1. It is.

  This facility is an additional installation for supplying air from the outside to the isolation request area A1. The facility uses the pressurizing device (25-28) when it is necessary to further pressurize the isolation request area A1 or when it is necessary to supply fresh air to reduce the carbon dioxide concentration or the like. Thus, it is possible to supply outside air with a reduced concentration of radioactive substance.

  The outside air supply facility can be performed using the recirculation line isolation valve 12, the recirculation filter device 11, and the recirculation blower 10. This is possible by introducing outside air from the inlet side of the recirculation line isolation valve 12 and configuring the line L to be introduced into the isolation request area A1. In FIG. 5, the system in this case is shown as an additional portion X41.

  The outside air supply facility can be introduced by introducing outside air using a recirculation line, but the following effects are produced by newly installing the additional portion X4. That is, in the new facility, unlike the conventional central control room ventilation air conditioning system, by providing an independent outside air intake line and a filter device for an accident, the introduced outside air is supplied to the pressurizing filter device 26 and the recirculation filter device 11. It is possible to pass through both, and it is expected that the removal rate of radioactive substances will be higher.

  As described above, according to the fifth embodiment, as a countermeasure for the third problem, the facility for supplying air from the outside to the isolation request area A1 is installed at the time of the accident, so that the work can be performed even when the radioactive noble gas is released. It is possible to protect personnel from exposure.

  FIG. 6 is a system diagram illustrating an overview of a central control room ventilation air conditioning facility of a nuclear power plant according to a sixth embodiment. In contrast to FIG. 5, a dotted line portion X5 is newly added in FIG. FIG. 6 also corresponds to the third problem due to the configuration of the additional portion X5.

  In the central control room ventilation air conditioning system of FIG. 6, the heating coil 29 is installed upstream of the pressurizing filter device 26 (on the pressurizing outside air inlet 28 side). The pressurizing filter device 26 is provided with a charcoal filter for the purpose of removing radioactive iodine.

  The efficiency of the charcoal filter decreases as the humidity increases. However, the efficiency of the charcoal filter can be prevented from decreasing by reducing the relative humidity by installing the heating coil 29 and heating the outside air.

  As described above, according to the sixth embodiment, as a countermeasure against the third problem, the heating coil 29 is installed on the upstream side of the pressurizing filter device 26, so that workers are protected from exposure even when radioactive noble gas is released. It is possible to do.

  FIG. 7 is a system diagram illustrating an overview of a central control room ventilation air conditioning facility of a nuclear power plant according to a seventh embodiment. Compared with FIGS. 5 and 6, a dotted line portion X <b> 6 is newly added in FIG. 7. FIG. 7 also corresponds to the third problem due to the configuration of the additional portion X6.

  In the central control room ventilation air conditioning system of FIG. 7, the heating coil 29 of FIG. 6 is changed to an electric heater 30.

  As described above, according to the seventh embodiment, as a countermeasure to the third problem, the electric heater 30 is installed on the upstream side of the pressurizing filter device 26, so that workers are protected from exposure even when radioactive noble gas is released. It is possible to do.

  FIG. 8 is a system diagram illustrating an overview of a central control room ventilation air conditioning facility of a nuclear power plant according to an eighth embodiment. Compared with FIGS. 5, 6, and 7, a dotted line portion X <b> 7 is newly added in FIG. 8. FIG. 8 also corresponds to the third problem due to the configuration of the additional portion X7.

  In the central control room ventilation air conditioner of FIG. 7, a pressurizing air cylinder 31 that pressurizes the inside of the isolation request area A1 and supplies fresh air is connected.

  When it is necessary to pressurize the isolation required area A1, or when it is necessary to supply fresh air to the isolation required area A1 for reasons such as reducing carbon dioxide concentration, fresh air is used using the pressurizing air cylinder 31. Is directly supplied to the isolation request area A1, so that the request can be satisfied.

  The pressurizing air cylinder 31 performs a filter vent or the like after an accident, and in a situation where radioactive rare gas that cannot be processed by the charcoal filter included in the recirculation filter device 11 and the pressurizing filter device 26 is included in the external environment. Also has the advantage of being usable.

  As described above, according to the eighth embodiment, as a countermeasure against the third problem, the pressurization air cylinder 31 that pressurizes the inside of the isolation request area A1 and supplies fresh air is connected. It is possible to protect workers from exposure.

A1: Isolation request area A2: Other area A3: Passage area B: Building D13, D23: Inter-area duct DA: Pressurization duct DI1, DI2: Air supply duct DO: Exhaust duct DR: Recirculation duct 5: Blower 6: Supply Air treatment device 7: Air supply isolation valve 8: Outside air intake 10: Recirculation blower 11: Recirculation filter device 12: Recirculation line isolation valve 14: Blower 15: Exhaust isolation valve 16: Exhaust port 19: Differential pressure gauge 20 : Differential pressure control device 21: differential pressure adjustment damper 22: isolation required area isolation valve 23: local cooler 25: pressurization blower 26: pressurization filter device 27: pressurization air supply isolation valve 28: pressurization outside air intake port 29: Heating coil 30: Electric heater 31: Pressurizing air cylinder

Claims (12)

A building is divided into an isolation requirement area including a central control room and other areas, and a first air supply duct in which a blower and an air supply processing device are installed to supply air from outside to the building area, and the building A recirculation duct in which a recirculation fan and a recirculation filter device are installed to exhaust air from the interior and introduce air into the building again, an exhaust duct in which an exhaust fan is installed to exhaust from the building, Consists of inter-area ducts communicating between indoor areas ,
The other area is divided into a machine room area for storing equipment and a passage area, and at least the isolation request area and the machine room area are provided with the first air supply duct for supplying air from the outside. Ventilation air conditioning equipment for nuclear power plants. A ventilation air conditioning system for a nuclear power plant according to claim 1 ,
The recirculation duct recirculates the exhaust from the passage area, and is a ventilation air conditioning system for a nuclear power plant. A ventilation air conditioning system for a nuclear power plant according to claim 1 or claim 2 ,
A ventilation air conditioner for a nuclear power plant, wherein the exhaust duct is exhausted from the machine room area. A ventilation air conditioning system for a nuclear power plant according to any one of claims 1 to 3 ,
In the event of an accident at a nuclear power plant, the ventilation air conditioning system of the nuclear power plant is characterized in that the supply air from the first air supply duct and the exhaust air through the exhaust duct are shut off and the recirculation air supply is performed through the recirculation duct. . A ventilation air conditioner for a nuclear power plant according to any one of claims 1 to 4 ,
Depending on the pressure difference between the building and the atmosphere , the opening of the differential pressure adjustment damper provided in the recirculation duct is controlled to adjust the indoor pressure according to the fluctuation of atmospheric pressure, and positive pressure in the area ventilation air conditioning equipment of the nuclear power plant, characterized in that to keep. A ventilation air conditioning facility for a nuclear power plant according to any one of claims 1 to 5 ,
At the time of an accident at a nuclear power plant, the supply of air from the first supply duct to the isolation required area and the exhaust by the inter-area duct communicating between the isolation required area and other areas are shut off, and the isolation required area Ventilation and air conditioning equipment for nuclear power plants, characterized in that A ventilation air conditioning system for a nuclear power plant according to claim 6 ,
A ventilation air-conditioning system for a nuclear power plant, wherein cooling air from a local air-conditioning system is supplied to the isolation request area that is an independent area. A ventilation air conditioning system for a nuclear power plant according to claim 6 or 7 ,
In the nuclear power plant, the isolation request area, which is an independent area, is supplied with air from a second air supply duct in which a blower and an air supply processing device are installed to supply air from outside. Ventilation air conditioning equipment. A ventilation air conditioning system for a nuclear power plant according to claim 8 ,
The second air supply duct uses the first air supply duct, and is a ventilation air conditioner for a nuclear power plant. A ventilation air conditioning system for a nuclear power plant according to claim 8 or claim 9 ,
A ventilation air conditioning system for a nuclear power plant, comprising a charcoal filter for removing radioactive iodine upstream of the air supply processing device of the second air supply duct. A ventilation air conditioning system for a nuclear power plant according to claim 8 or claim 9 ,
A ventilation air conditioner for a nuclear power plant, comprising an electric heater for removing radioactive iodine on the upstream side of the air supply processing device of the second air supply duct. A ventilation air conditioner for a nuclear power plant according to any one of claims 6 to 11 ,
A ventilation air conditioning system for a nuclear power plant, characterized in that air is supplied from a pressurized air cylinder to the isolation request area which is an independent area.

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