JP4300097B2 - Ventilation air conditioning equipment for nuclear power plant and control method thereof - Google Patents

Description

  The present invention relates to a ventilation air conditioning facility for a nuclear power plant and a method for controlling the ventilation air conditioning facility, and in particular, when maintaining the room temperature in a building of a nuclear power plant is possible even if the ventilation air flow is reduced, the exhaust air flow is reduced and the public exposure is reduced. The present invention relates to a ventilation air-conditioning facility for a nuclear power plant capable of suppressing a dose and a control method thereof.

  Ventilation and air conditioning equipment at nuclear power plants supplies clean air to the building of the nuclear power plant, heats or cools the air as necessary, and cools the heat generated by each device installed in the building. While maintaining the building to have an appropriate room temperature, the radiation generated in the building's room should be kept within an appropriate value by ventilation, and when exhausted outside the nuclear power plant It is a facility that uses diffuse exhaust to keep the public exposure dose below the specified value. For this reason, the ventilation air-conditioning equipment includes a supply-side air-conditioning equipment that supplies clean air to an area that may contain radioactivity in the air such as a reactor building (hereinafter referred to as a radioactive area), and the above-mentioned radioactive area. And an exhaust-side air conditioning system that guides the exhaust air that has been ventilated to blow up from the exhaust pipe to a high place and diffuse it.

  This ventilation air-conditioning system at the nuclear power plant suppresses the radioactivity generated in the building interior to within an appropriate value by ventilation. On the other hand, when exhausting from the building outside the nuclear power plant, the exhaust is blown up to a high place from the stack. By diffusing and releasing, the public exposure dose is kept below the target value that is lower than the standard value stipulated by the Electricity Business Law, so that the surrounding environment is not adversely affected.

  As conventional ventilation air conditioning equipment for nuclear power plants, there are those disclosed in JP-A-3-183997 (Patent Document 1) and JP-A-6-230180 (Patent Document 2).

  The ventilation air conditioning system of a nuclear power plant disclosed in Patent Document 1 combines exhausts from radioactive buildings such as a reactor building, a turbine building, and a waste treatment building, and uses the waste heat of the nuclear power plant after this merging. The exhaust is heated to raise the temperature. The exhaust from the nuclear power plant is diffused and released from the height of the exhaust stack, or the exhaust temperature is raised, so that the rising action force by natural convection is increased and blown up from the exhaust stack to a higher position, and exposed to the public. The dose equivalent of the dose is further reduced.

Moreover, the ventilation air conditioning equipment of the nuclear power plant disclosed in Patent Document 2 is combined with the exhaust from each building such as the reactor building and the air from the non-radioactive area such as the seawater heat exchanger building to form an exhaust pipe. The amount of exhaust gas diffused and released from the high part of the stack is controlled below the radioactive concentration specified in the Electricity Business Law, etc., and sufficient consideration is given so as not to adversely affect the surrounding environment of the nuclear power plant. ing.
JP-A-3-183997 JP-A-6-230180

  In conventional nuclear power plant ventilation and air conditioning systems, the supply air temperature during cooling in summer is the highest in the design, so calculations are made so that each room in the nuclear power plant building can be maintained at an appropriate temperature at this supply air temperature. The rated capacity (rated supply air volume and rated exhaust air volume) of the supply fan of the supply side air conditioning equipment and the exhaust fan of the exhaust side air conditioning equipment is determined based on the total supply air volume.

  In this nuclear power plant ventilation air conditioning system, if the outside air temperature is low in winter, etc., and the air supply temperature is low even if it is not cooled by the cooler of the air supply side air conditioning system, the supply air volume is reduced. In addition, each room of the building can be sufficiently maintained at a predetermined room temperature.

  However, when the supply air volume is reduced, the exhaust air volume is also reduced, the flow velocity at the outlet of the exhaust pipe is lowered, and the effective height of the discharge source is lowered. Depending on the effective height of the emission source, the public exposure dose evaluated during the construction of the nuclear power plant will change. The public exposure dose decreases as the effective height of the emission source increases. When the exhaust air volume is small and the effective height of the radiation source is low, there is a possibility that the public exposure dose will be locally increased, although it is below the value specified by the Electricity Business Act.

  At present, the supply fan of the air supply side air conditioning equipment and the exhaust fan of the exhaust side air conditioning equipment are operated at the rated air volume throughout the year, and the high velocity is blown out from the exhaust pipe so that the flow velocity at the exhaust pipe outlet exceeds the predetermined value. Is going. By operating the air supply and exhaust fans at the rated air flow rate, the public exposure dose evaluated at the time of construction of the nuclear power plant is maintained below a large specified value, and consideration is given so as not to adversely affect the surrounding environment. .

  However, since air supply fans and exhaust fans are used for indoor ventilation of buildings such as reactor buildings, fan motors need to be operated with a large (water head) head difference and require a large driving force. There is a problem that a large amount of energy is consumed (power consumption).

  The present invention has been made in consideration of the above-described circumstances. When the supply air volume can be reduced and the room temperature of the building of the nuclear power plant can be maintained, the supply air volume and the exhaust air volume can be reduced, and the power energy can be reduced. An object of the present invention is to provide a ventilation air-conditioning facility for a nuclear power plant and a control method thereof that can reduce consumption while significantly reducing the public exposure dose from a specified value.

In order to solve the above-described problems, a ventilation air conditioning system for a nuclear power plant according to the present invention includes a cooling / heating device and an air supply fan, and the outside air is radiated from the radioactive zone of the nuclear power plant. Supply air-conditioning equipment, exhaust-side air-conditioning equipment having an exhaust fan for exhausting the air ventilated in the radioactive area, and exhaust pipe that diffuses and discharges the exhaust from the exhaust-side air-conditioning equipment into the atmosphere from high places If, when the radioactivity concentration in the exhaust was measured through a radioactivity detector, this measured activity concentration equal to or greater than building the generated radioactive concentration satisfying public dose calculated air volume reduction A radioactivity concentration detection device that outputs a restriction signal; and a thermometer provided at least at one location downstream of the supply fan of the supply side air conditioning equipment, inside the building of the radioactive area, or downstream of the radioactive area; and Temperature from thermometer An air flow control device for controlling the air flow of the air supply facility and the exhaust air fan of the exhaust air conditioning facility based on the output signal so as to reduce the amount of air that is supplied to or exhausted from the radioactive area; If the limit signal is input to the air volume control device, the air supply fan and the exhaust fan, the temperature detection signal operation control is stopped by, and is controlled actuated by the air flow reduction limit signal.

Further, in order to solve the above-described problems, a ventilation air-conditioning facility for a nuclear power plant according to the present invention is characterized in that, as described in claim 2, the radioactivity concentration detection device includes an exhaust air volume from a building of the nuclear power plant. The radioactivity concentration detection device further measures a radioactivity concentration in the exhaust gas, calculates a necessary exhaust air volume required for the measured radioactivity measurement value, and calculates the calculation result. When the exhaust air volume measured by the flow meter is smaller than the required exhaust air volume, an air volume reduction restriction signal is output, and when the air volume reduction restriction signal is input to the air volume control device, the air supply fan and the exhaust gas are exhausted. The fan is controlled by the temperature detection signal , and is controlled by the air volume reduction restriction signal .

On the other hand, the ventilation air conditioning control method for a nuclear power plant according to the present invention has a cooling / heating device and an air supply fan as described in claim 4 in order to solve the above-described problems. Supply air-conditioning equipment that supplies air to the radioactive area, exhaust-side air-conditioning equipment that has an exhaust fan that exhausts the air that ventilated the radioactive area, and exhaust from the exhaust-side air-conditioning equipment diffuses into the atmosphere from high places an exhaust pipe that, the radioactivity concentration in the exhaust was measured through a radioactivity detector, when this measured activity concentration equal to or greater than building the generated radioactive concentration satisfying public dose calculated , A radioactivity concentration detection device for outputting an air volume reduction restriction signal, and a thermometer provided at least at one location on the downstream side of the supply fan of the supply side air-conditioning equipment, in the building of the radioactive section, or on the downstream side of the radioactive section And air supply side air conditioning In a ventilation air conditioning control method for a nuclear power plant having an air supply control device for operating and controlling the amount of air supplied to or exhausted from an air supply facility and an exhaust fan of an exhaust air conditioning facility, the temperature from the thermometer a step of, based on the detection signal air volume control device for reducing the air volume which is air supply or exhaust the radioactive zone, if the air amount reducing limit signal is input to the air volume control device, the air supply fan and the exhaust fan, the The operation control by the temperature detection signal is stopped, and the operation is controlled by the air volume reduction restriction signal .

  According to the ventilation air-conditioning equipment and control method of a nuclear power plant according to the present invention, when room temperature can be maintained even if the air supply amount to each building of the nuclear power plant is reduced, the supply air amount and thus the exhaust air amount are reduced. As a result, the consumption of electric power can be reduced, while the public exposure dose can be significantly reduced from the specified value.

  If the supply air temperature is low and the room temperature can be maintained in each building of the nuclear power plant even if the supply air volume is reduced, the supply air volume to each building and thus the exhaust air volume can be reduced, greatly increasing the electric energy consumption. It is possible to reduce the air-conditioning costs and the fan power of the air supply fan and the exhaust fan.

  DESCRIPTION OF EMBODIMENTS Embodiments of a ventilation air-conditioning facility and control method for a nuclear power plant according to the present invention will be described with reference to the accompanying drawings.

  FIG. 1 is a schematic view systematically illustrating a first embodiment of a ventilation air conditioning facility for a nuclear power plant according to the present invention.

  This nuclear power plant 10 includes a reactor building 11 constructed on the site of the nuclear power plant, a turbine building (not shown), a radioactive waste treatment building, and the like. The reactor building 11, the turbine building, the radioactive waste The processing building has an area (hereinafter referred to as a radioactive area 12) that may contain radioactivity in the air. The ventilation air conditioner in the radioactive area 12 includes an air supply side air conditioner 13 that supplies clean outside air to the radioactive area 12, an exhaust side air conditioner 14 that guides exhaust from the radioactive area 12, and the exhaust side air conditioner 14 And an exhaust cylinder 15 for diffusing and releasing the exhaust from the high place to the atmosphere.

  The air supply side air conditioner 13 is configured to remove the outside air taken in from the outside air intake port 17 and clean it, and to cool or heat the outside air (air) cleaned by the air supply filter 18. A heater 19 and a plurality of air supply fans 21 that supply clean air from the cooler / heater 19 into the reactor building 11 in the radioactive zone 12 through the air supply duct 20. The cooling / heating device 19 may be configured as an integrated structure in which the cooling coil and the heating coil are accommodated in one casing, or may be configured by connecting independent cooling devices and heating devices in series.

  For example, four air supply fans 21 are arranged in parallel, and one of them is configured as a spare air supply fan. Further, the air supply duct 20 is provided with an isolation valve 22, and the partition valve 22 can isolate the inside of the reactor building 11 from the surroundings in an emergency.

For example, in the boiling water nuclear power plant 1.1 million kW class, the ventilation air volume of approximately 200,000 m ^{3 /} hr during reactor operation the reactor building 11 is guided, in the turbine building approximately 400,000 m ³ / Hr ventilation air volume is guided.

  On the other hand, the exhaust-side air conditioning equipment 14 is filtered by an exhaust filter 26 that filters the exhaust discharged from the reactor building 11 through the exhaust duct 25 to remove part of the particulate radioactivity, and the exhaust filter 26. And a plurality of exhaust fans 27 for blowing the exhaust gas from which foreign matter has been removed. The exhaust fans 27 pass through the main exhaust duct 28 and are guided to the (main) exhaust cylinder 15. The exhaust fan 27 has, for example, four units, and one unit is configured as a spare exhaust fan.

  An isolation valve 29 is provided in the exhaust duct 25 for guiding the exhaust from the reactor building 11 to the exhaust side air conditioning equipment 14, and this isolation valve 29 cooperates with the isolation valve 22 of the air supply side air conditioning equipment 13. The inside of the reactor building 11 can be isolated from the surroundings. The isolation valves 22 and 29 are automatically closed when the radiation dose (radioactivity concentration) of the exhaust gas passing through the exhaust duct 25 exceeds a predetermined value, and the release of the radioactive gas is performed to ventilate the nuclear power plant 10. The air conditioner is switched to an emergency gas processing system (not shown).

  In addition, an exhaust duct 30 from the turbine building and an exhaust duct 31 from the radioactive waste treatment building are connected to the main exhaust duct 28 of the exhaust-side air conditioning equipment 14, and the exhaust from the reactor building 11 is transmitted to the turbine building and the radioactive building. The exhaust gas from the waste building is joined to the exhaust cylinder 15.

  The exhaust stack 15 has a ground height H different from the topography of the construction site of the nuclear power plant, but generally has a ground height H of several hundreds of meters, for example 150 m. The exhaust cylinder 15 changes the height of the exhaust air exhausted from the top outlet according to the change in the amount of exhaust air flowing through the inside or the exhaust duct 25, and is usually several tens of meters, for example, 20 m to 30 m. Exhaust gas is diffused and released into the atmosphere from high altitudes.

The exhaust height ΔH (m) of the exhaust from the exhaust cylinder 15 is

It is represented by

  From this equation (1), it can be seen that the blowing height ΔH depends on the diameter and flow velocity of the outlet of the exhaust cylinder 15, and the blowing height ΔH has a relationship of (ΔH∝flow velocity / caliber).

Considering this blowing height ΔH, the effective height V of the emission source is theoretically a value obtained by adding the blowing height ΔH to the ground height H of the exhaust pipe 15 (H + ΔH). As the effective height V _H of the emission source, a value (V _H ≦ V) obtained by correcting the added value in the wind tunnel experiment is used.

  FIG. 2 is a diagram illustrating a method for evaluating a public exposure dose from a nuclear power plant.

When evaluating the public exposure dose, the boundary of the site of the nuclear power plant is divided into, for example, 16 directions with the (main) exhaust pipe 15 as the center, and the effective emission source is determined for each peripheral monitoring area boundary point P of the nuclear power plant. as building the generated radiation from the height V _H is diffused, in consideration of wind direction and velocity frequency annually in effective height V _H of the emission source to calculate the annual average concentration of radiation dose, calculated radiation dose is doing. Reference numeral 44 denotes a turbine building.

Using the relationship described above, the exhaust air volume evaluated at the time of construction of the nuclear power plant from the estimated radiation concentration generated at the time of construction of the nuclear power plant and the amount of public exposure assessed at the time of construction of the nuclear power plant ( Supply air volume). At this time, the radiation concentration actually generated in the reactor building is smaller than the assumed radiation concentration generated during the construction of the nuclear power plant. (Evaluated supply airflow))) Even if the exhaust airflow (supply airflow) is smaller, the actual public exposure dose should satisfy the public exposure dose evaluated at the time of nuclear power plant construction. it can.

  On the other hand, the ventilation air conditioning system of the nuclear power plant 10 measures the radioactivity concentration in the atmosphere passing through the main exhaust duct 28, and outputs a radioactivity concentration detection device 35 that outputs an air volume reduction restriction signal, and this concentration detection signal. An air volume control device 36 that inputs and controls the air supply fan 21 of the air supply side air conditioning facility 13 and the exhaust fan 27 of the exhaust side air conditioning facility 14; and a thermometer 37 that outputs a temperature detection signal to the air volume control device 36; Is provided.

  The thermometer 37 is provided on the downstream side of the air supply side air conditioning equipment 13, for example, in the air supply duct 20, and measures and detects the temperature of the air supply passing through the air supply duct 20. The thermometer 37 may be provided in the building of the radioactive zone 12 such as the reactor building 11 or on the downstream side of the radioactive zone 12. A temperature detection signal from a thermometer 37 provided in at least one location downstream of the air supply side air conditioning equipment 13, in the building of the radioactive zone 12 and downstream of the radioactive zone 12 is input to the air volume control device 36.

  In the air volume control device 36, a relational expression between the supply air temperature (or ventilation temperature, exhaust temperature) and the minimum supply air volume (or minimum exhaust air volume) is set in advance, and the supply air temperature detected by the thermometer 37 is set. Accordingly, the required minimum supply air volume is calculated by the air volume control device 36. The air volume control device 36 determines the possibility of air volume reduction according to the supply air temperature (or ventilation temperature, exhaust temperature) detected by the thermometer 37, and reduces the air volume to the minimum supply air volume within the range of air volume reduction possibility. The air supply fan 21 and the exhaust fan 27 are controlled to operate.

  Specifically, the air volume reduction is provided on the upstream side or the downstream side of the air supply fan 21 and the exhaust fan 27, or the number of fan operations of the air supply fan 21 and the exhaust fan 27 is controlled, the number of fan rotations is controlled. This is done by adjusting the aperture of an adjustment damper (not shown).

By the way, when the air volume is reduced by controlling the operation of the air supply fan 21 and the exhaust fan 27, the exhaust air volume is reduced, and the blowout flow rate from the exhaust cylinder 17 is reduced. If the blowing velocity is reduced, the effective height V _H of the radioactive emitter is lowered, there is a fear that the public dose is increased locally.

When blowing air volume from the exhaust pipe 15 is reduced, since the effective height V _H of the radioactive emitter is lowered, assuming that blowing velocity is exhausted, the effective height of emission source when the blowout velocity is gone Calculate the radioactive concentration generated in the radioactive area 11 of the nuclear power plant where the amount of public exposure required when V _H1 is the ground height H of the stack 15 is the public exposure dose evaluated during the construction of the nuclear power plant Is calculated in advance. The calculated radioactive concentration generated in the building is set in advance in the radioactive concentration detector 35 as a set value. Therefore, if the radioactivity concentration generated in the building is less than or equal to the radioactivity concentration generated in this way, the public exposure dose will be It is possible to satisfy the public exposure dose evaluated at the time of power plant construction.

  The radioactivity concentration detection device 35 has a radioactivity detector 38 for measuring the radioactivity concentration in the exhaust gas passing through the main exhaust duct 28, and a concentration when the detected radioactivity concentration is equal to or higher than a predetermined set value. And a transmitter 39 that outputs a detection signal to the air volume control device 36.

  The radioactivity concentration detection device 35 outputs an air volume reduction restriction signal from the transmitter 39 to the air volume control device 36 when the radioactivity detector 38 becomes equal to or higher than the calculated radioactivity concentration (set value) in the building. Then, the operation control of the air supply fan 21 and the exhaust fan 27 by the temperature detection signal from the thermometer 37 is stopped, and the air supply fan 21 is adjusted so that the air supply air volume (evaluated air supply volume) evaluated at the time of nuclear power plant construction is obtained. Further, the operation control of the exhaust fan 27 is performed. The air volume control device 36 is controlled by the concentration detection signal from the radioactivity concentration detection device 35 in preference to the temperature detection signal from the thermometer 37.

  Although the example in which the radiation detector 38 is provided in the straight pipe portion of the main exhaust duct 28 is illustrated, the radiation detector 38 may be inside the exhaust cylinder 15 and is discharged from the exhaust-side air conditioning equipment 14. It may be installed in a place where the radioactivity concentration contained in the exhaust gas can be accurately measured.

  However, even if the radioactivity concentration generates an air volume reduction restriction signal that is smaller than the assumed radioactivity concentration generated in the building used for evaluation at the time of construction of the nuclear power plant, the radioactivity concentration actually generated in the building of the nuclear power plant It is not so rare that the air volume reduction limit signal, which is a concentration detection signal, is emitted from the radioactive concentration detection device 35 more sufficiently.

  In the present embodiment, the case where the control is performed using the supply air volume is shown, but the control can also be performed using the exhaust air volume. In this case, the exhaust air volume evaluated at the time of construction of the nuclear power plant (evaluated exhaust air volume) may be used instead of the evaluated supply air volume.

  Next, the effect | action of the ventilation air conditioning equipment of a nuclear power station is demonstrated.

  When the ventilation air conditioning facility of the nuclear power plant 10 is activated, the outside air taken in from the outside air intake port 17 of the air supply side air conditioning facility 13 is removed by the air supply filter 18 and cleaned. The cleaned outside air is adjusted to a predetermined temperature by the cooling / heating device 19. The outside air is cooled as necessary in the summer or intermediate period and heated as necessary in the winter, and then blown through the air supply duct 20 to each room of the reactor building 11 in the radioactive zone 12 by the air supply fan 21. Is done.

  The outside air sent to each room of the reactor building 11 removes heat generated from the indoor installation equipment, ventilates each room, and is guided to the exhaust-side air conditioning equipment 14 by the exhaust duct 25.

Exhaust gas collected from each chamber of the reactor building 11 by the exhaust duct 25 removes part of the particulate radioactivity by the exhaust filter 26 of the exhaust-side air conditioning equipment 14, and then the main exhaust by the exhaust fan 27. It is sent to the exhaust pipe 15 through the duct 28, blown up from the top outlet of the exhaust pipe 15 by several tens of meters, for example, about 30 m, and diffused and exhausted at a high place. Exhaust ducts 30 and 31 from other buildings that may contain radioactivity in the exhaust are also connected to the exhaust cylinder 15 or the main exhaust duct 28, and the exhaust pipes 15 and 31 from other buildings are also joined. It is diffused and exhausted from high places.

  According to the ventilation air conditioning equipment of this nuclear power plant 10, a thermometer 37 is provided downstream of the air supply side air conditioning equipment 13 (or in the building of the radioactive area 12, downstream of the radioactive area 12) to supply air temperature (ventilation). Temperature or exhaust temperature) is detected, and a minimum supply air volume that can maintain the building of the nuclear power plant at an appropriate room temperature is obtained from the detected supply air temperature by the air volume control device 36. 21 and the exhaust fan 27 are controlled to be reduced so that the supply air volume and thus the exhaust air volume can be allowed to become the minimum supply air volume and thus the minimum value of the exhaust air volume.

  In this way, even if the supply air volume or the exhaust air volume is reduced, the building of the nuclear power plant can be maintained at an appropriate room temperature, and the building in the radioactive area 12 can be ventilated while maintaining the room temperature.

  By reducing the supply air volume or the exhaust air volume, if the radioactivity detector 38 of the radioactivity concentration detection device 35 detects a radioactivity concentration higher than a preset value, the air volume is reduced from the transmitter 39. The restriction signal is output to the air volume control device 36. The air volume control device 36 receives the input of the air volume reduction restriction signal and is controlled to operate the air supply fan 21 and the exhaust fan 27 so as not to reduce the air volume from the evaluation air supply air volume. The amount of public exposure that is being evaluated at the time of construction of the plant will not be exceeded.

  As described above, according to the ventilation air conditioning system of the nuclear power plant 10 shown in FIG. 1, the supply air flow rate and the exhaust air flow rate are satisfied after satisfying the public exposure amount evaluated at the time of construction of the nuclear power plant. It is possible to prevent wasteful energy consumption in the operation of the air supply fan and the exhaust fan.

  In addition, since the supply air volume is reduced, the energy for cooling or heating the supply air can be reduced, so that the cooling cost can be reduced in the summer and the heating cost can be reduced in the winter. Can do.

  Further, by reducing the exhaust air volume from each building of the nuclear power plant, the filter life of the air supply filter 18 and the exhaust filter 26 can be extended, while the waste amount of the exhaust filter can be reduced. The amount of radioactive waste can be reduced. Since the amount of outside air sent to each building can be reduced, adverse effects caused by bringing salt into the outside air can also be reduced.

  FIG. 3 is a simplified system diagram showing a second embodiment of a ventilation air conditioning facility for a nuclear power plant according to the present invention.

  The ventilation air conditioning equipment of the nuclear power plant 10A shown in this embodiment is different from the ventilation air conditioning equipment of the nuclear power plant 10 shown in FIG. Therefore, the same parts are denoted by the same reference numerals and description thereof is omitted.

  The radioactivity concentration detection device 45 is installed in the exhaust duct 28 to measure the exhaust air volume, the radioactivity detector 38 to detect the radioactivity concentration in the exhaust gas passing through the exhaust duct 28, and the flow meter. A transmitter 47 for inputting a flow rate measurement signal from 46 and a radioactivity concentration measurement signal from the radioactivity detector 38 is provided. The installation positions of the flow meter 46 and the radioactivity detector 38 may be in the exhaust pipe 15 and are not limited to the main exhaust duct 28.

  In the present embodiment, the indoor radioactivity concentration and the exhaust air volume that satisfies the public exposure dose evaluated at the time of construction of the nuclear power plant in the indoor radioactivity concentration (hereinafter referred to as necessary exhaust air volume) are obtained. Therefore, the required exhaust air volume is a function of the building radioactive concentration. The radioactivity concentration in the building may be a function of the required exhaust air volume.

The transmitter 47 generates an air volume reduction restriction signal from the transmitter 47 when the exhaust flow rate measured by the flow meter 46 becomes smaller than the required exhaust air volume obtained from the radioactivity concentration from the radioactivity detector 38. This signal is output to the air volume control device 36. The air volume control device 36 receives an air volume reduction restriction signal from a transmitter 47, and the air volume of the supply fan 21 of the supply side air conditioning equipment 13 and the exhaust fan 27 of the exhaust side air conditioning equipment 14 is detected by a temperature detection signal from the thermometer 37. The operation control is stopped so as to reduce, and the supply fan 21 and the exhaust fan 27 are controlled so that the exhaust air amount becomes the necessary exhaust air amount or the evaluation exhaust air amount.

  The transmitter 47 calculates the radioactivity concentration in the building that satisfies the public exposure dose evaluated at the time of construction of the nuclear power plant at the exhaust flow rate measured by the flow meter 46, and the radioactivity is calculated from the calculated radioactivity concentration in the building. When the radioactivity concentration from the detector 38 becomes large, the operation control of the supply fan 21 and the exhaust fan 27 of the supply fan 21 and the exhaust fan 27 so as to reduce the air volume by the temperature detection signal from the thermometer 37 is stopped. The operation of the supply fan 21 and the exhaust fan 27 may be controlled so that the evaluation exhaust air volume is obtained.

  According to this embodiment, the transmitter 47 of the radioactivity concentration detection device 35 detects the measured exhaust air volume and the actual radioactivity concentration and generates the air volume reduction restriction signal, and therefore generates the air volume reduction restriction signal. The actually measured radioactivity concentration is higher than the actually measured radioactivity concentration value shown in the first embodiment. As a result, the frequency at which the air volume reduction restriction signal is generated is further reduced than in the first embodiment, and wasteful energy consumption can be further prevented in the air supply fan 21 and the exhaust fan 27, as shown in the first embodiment. As with the ventilated air-conditioning equipment of the nuclear power plant 10 that has been made, the fan power costs of the supply fan 21 and the exhaust fan 27 can be reduced.

  Furthermore, by reducing the amount of air supply and exhaust air to each building of the nuclear power plant, the cooling and heating costs can be reduced, the life of the air supply filter 18 and the exhaust filter 26 can be extended, and the amount of filter waste The amount of radioactive waste can be reduced. In addition, by reducing the amount of outside air taken in from the outside air inlet (supply air volume), it is possible to effectively prevent adverse effects caused by bringing salt into the outside air.

  At this time, also in the second embodiment, the public exposure dose can always satisfy the public exposure dose evaluated at the time of construction of the nuclear power plant.

  In the embodiment of the present invention, an example is shown in which the present invention is applied to a boiling water nuclear power plant. However, the ventilation air-conditioning equipment and control method of this nuclear power plant can also be applied to a pressurized water nuclear power plant. .

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a simplified system diagram showing a first embodiment of a ventilation air conditioning facility and control method for a nuclear power plant according to the present invention. Explanatory drawing which shows the evaluation method of the public exposure dose of a nuclear power plant. The simplified systematic diagram which shows 2nd Embodiment of the ventilation air-conditioning installation and control method of the nuclear power plant which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10,10A Nuclear power plant 11 Reactor building 12 Radioactive area 13 Supply side air conditioner 14 Exhaust side air conditioner 15 Exhaust pipe 17 Outside air intake 18 Supply filter 19 Cooling / heating device (cooler and heater)
20 Air supply duct 21 Air supply fans 22 and 29 Isolation valve 25 Exhaust duct 26 Exhaust filter 27 Exhaust fan 28 Main exhaust ducts 30 and 31 Exhaust duct 35 Radioactivity concentration detector 36 Air flow control device 37 Thermometer 38 Radioactivity detector 39 Transmitter 45 Radioactivity concentration detector 46 Flow meter 47 Transmitter

Claims (4)

An air supply side air conditioning system having a cooling / heating device and an air supply fan to supply outside air to the radioactive area of the nuclear power plant;
An exhaust-side air conditioning system having an exhaust fan from which air ventilating the radioactive area is exhausted;
An exhaust pipe that diffuses and discharges the exhaust from the exhaust side air-conditioning equipment into the atmosphere from a high place,
When the radioactivity concentration in the exhaust was measured through a radioactivity detector, this measured activity concentration equal to or greater than building the generated radioactive concentration satisfying public dose calculated air volume reduction limit signal Radioactivity concentration detection device that outputs,
A thermometer provided in at least one location on the downstream side of the air supply fan of the air supply side air conditioning facility, in the building of the radioactive area, or downstream of the radioactive area;
An air volume control device for operating and controlling the air supply fan of the air supply side air conditioning equipment and the exhaust fan of the exhaust side air conditioning equipment based on the temperature detection signal from the thermometer so as to reduce the air volume supplied or exhausted to the radioactive area; With
When the air volume reduction limit signal is input to the air volume control device, the air supply fan and the exhaust fan, the temperature detection signal operation control is canceled by a being controlled actuated by the air flow reduction limit signal Ventilation air conditioning equipment for nuclear power plants. The radioactivity concentration detection apparatus further includes a flow meter for measuring an exhaust air volume from a building of a nuclear power plant,
This radioactivity concentration detection device measures the radioactivity concentration in the exhaust gas, calculates the required exhaust air volume required for the measured radioactivity measurement value, and calculates the required exhaust air volume from the calculated required exhaust air volume with the flow meter . When the measured exhaust air volume becomes small, an air volume reduction restriction signal is output,
When the air volume reduction restriction signal is input to the air volume control device, the air supply fan and the exhaust fan are stopped from operating control by the temperature detection signal, and are controlled by the air volume reduction restriction signal. A ventilation air conditioning system for a nuclear power plant according to claim 1. The radioactivity concentration detection apparatus further includes a flow meter for measuring an exhaust air volume from a building of a nuclear power plant,
The radioactivity concentration detection device calculates the radioactivity concentration in the building at the exhaust flow rate measured by the flow meter, and the radioactivity concentration measured by the radioactivity detector from the calculated radioactivity concentration in the building. When the air pressure increases, an air volume reduction limit signal is output,
When the air volume reduction restriction signal is input to the air volume control device, the air supply fan and the exhaust fan are stopped from operating control by the temperature detection signal, and are controlled by the air volume reduction restriction signal. A ventilation air conditioning system for a nuclear power plant according to claim 1. An air supply side air conditioning system having a cooling / heating device and an air supply fan to supply outside air to the radioactive area of the nuclear power plant;
An exhaust-side air conditioning system having an exhaust fan from which air ventilating the radioactive area is exhausted;
An exhaust pipe that diffuses and discharges the exhaust from the exhaust side air-conditioning equipment into the atmosphere from a high place,
When the radioactivity concentration in the exhaust was measured through a radioactivity detector, this measured activity concentration equal to or greater than building the generated radioactive concentration satisfying public dose calculated air volume reduction limit signal Radioactivity concentration detection device that outputs,
A thermometer provided in at least one location on the downstream side of the air supply fan of the air supply side air conditioning facility, in the building of the radioactive area, or downstream of the radioactive area;
In a ventilation air conditioning control method for a nuclear power plant having an air volume control device for operating and controlling an air volume supplied or exhausted to a radioactive area from an air supply fan of an air supply side air conditioning equipment and an exhaust fan of an exhaust side air conditioning equipment,
A step of reducing the air volume supplied or exhausted to the radioactive area by the air volume control device based on a temperature detection signal from the thermometer;
When the air volume reduction limit signal is input to the air volume control device, the air supply fan and the exhaust fan, the temperature detection signal operation control is canceled due, and a step which is controlled actuated by the air flow reduction limit signal Ventilation air-conditioning control method for nuclear power plant.

Images