JP2019152484A - Filter vent facility, filter vent method, and nuclear plant - Google Patents

Abstract

To provide a compact filter vent facility which does not require a large scrubber container or a water storage tank.SOLUTION: A filter vent facility that processes an ambient gas inside a reactor containment vessel 3 includes a venturi nozzle 12; a vent pipe 5 for connecting a vapor phase portion and the venturi nozzle of the reactor containment vessel; a nozzle piping 13 for connecting a liquid phase portion of the reactor containment vessel and a throttle portion 12a of the venturi nozzle; a gas-liquid separator 14 disposed downstream of the venturi nozzle; a return pipe 15 for returning water separated by the gas-liquid separator back to the liquid phase portion of the reactor containment vessel; and an exhaust piping 6 for discharging the ambient gas separated by the gas-liquid separator outdoors.SELECTED DRAWING: Figure 1

Description

  Embodiments described herein relate generally to a filter vent facility, a filter vent method, and a nuclear power plant used in a nuclear power plant.

  Generally, a filter vent facility is provided as a facility for preventing damage to the reactor containment vessel when there is a possibility of significant damage to the core of a nuclear power plant or when significant damage occurs in the core.

  When the internal pressure of the containment vessel rises, the filter vent equipment introduces atmospheric gas from the dry well or suppression chamber of the containment vessel to the scrubber vessel, removes radioactive substances contained in the atmospheric gas from the atmospheric gas, and then removes from the exhaust stack. Release into the atmosphere.

The scrubber vessel is composed of a venturi nozzle and water kept at a predetermined water level, and the atmospheric gas released from the reactor containment vessel is brought into contact with water by the venturi nozzle to transfer the radioactive substance from the atmospheric gas to the water ( Scrubbing effect). A water storage tank is installed to adjust the water level in the scrubber container.
The filter vent facility reduces the pressure of the reactor containment vessel through the above-described process, prevents damage due to overpressure, and suppresses the amount of radioactive material released to the atmosphere.

Special table 2009-513926 gazette

  In the conventional filter vent equipment described above, the water in the scrubber vessel may evaporate due to the heat generated from the radioactive material, and the water level may decrease. When the water level falls below the height of the venturi nozzle, the function of removing the radioactive material by the venturi nozzle is lost.

  Therefore, in order to maintain the function of removing the radioactive substance of the venturi nozzle, it is necessary to store the amount of water in the scrubber container in view of the amount of evaporation, and there is a problem that the scrubber container is enlarged.

  Further, if the radioactive material removal function of the venturi nozzle is to be maintained for a long time, it is necessary to provide a water storage tank for replenishing water from the outside, and there is a problem that the equipment becomes large.

  Embodiments of the present invention have been made to solve the above-described problems, and an object thereof is to provide a compact filter vent facility, a filter vent method, and a nuclear power plant that do not require a large scrubber container or a water storage tank.

  In order to solve the above-described problem, a filter vent facility according to the present embodiment includes a venturi nozzle, a gas phase portion of the reactor containment vessel, and a filter vent facility that processes atmospheric gas inside the reactor containment vessel. A vent pipe connecting a venturi nozzle, a nozzle pipe connecting a liquid phase part of the reactor containment vessel and a throttle part of the venturi nozzle, a steam separator provided downstream of the venturi nozzle, and the gas A return pipe for returning the water separated by the water separator to the liquid phase part of the reactor containment vessel, and an exhaust pipe for releasing the atmospheric gas separated by the steam separator to the outside.

  Further, the filter vent facility according to the present embodiment includes a scrubber vessel disposed below the liquid surface of the liquid phase portion of the reactor containment vessel in the filter vent facility for processing the atmospheric gas inside the reactor containment vessel. A venturi nozzle provided inside the scrubber vessel, a water level meter for measuring the water level of the scrubber vessel, a vent pipe connecting the gas phase portion of the reactor containment vessel and the venturi nozzle, and the reactor containment A replenishment pipe connecting the liquid phase part of the container and the scrubber container, a water level adjustment valve provided in the replenishment pipe and opened and closed according to the measured value of the water level meter, and provided downstream of the scrubber container A steam / water separator, a return pipe for returning the water separated by the steam / water separator to the scrubber container, and an exhaust pipe for releasing the atmospheric gas separated by the steam / water separator to the outside , Comprising a.

  Further, the filter vent method according to the present embodiment causes the atmosphere gas in the reactor containment vessel to be guided to the venturi nozzle so that the water in the liquid phase portion of the reactor containment vessel is sucked into the throttle portion of the venturi nozzle, and the atmosphere A step of scrubbing the gas, a step of separating the mixed fluid of the atmospheric gas and water after the scrubbing step into the air, a step of releasing the atmospheric gas after the separation of the water into the atmosphere, and the water after the separation of the water Returning to the liquid phase part of the reactor containment vessel.

  Further, the nuclear power plant according to the present embodiment includes a nuclear reactor building, a secondary containment facility enclosed in the reactor building and configured to be airtight, and a liquid that is contained in the secondary containment facility and stores water. A reactor containment vessel having a phase portion therein, a venturi nozzle, a vent pipe connecting the gas phase portion of the reactor containment vessel and the venturi nozzle, a liquid phase portion of the reactor containment vessel, and the venturi nozzle A nozzle pipe for connecting the throttle part, a steam / water separator provided on the downstream side of the venturi nozzle, and a return pipe for returning the water separated by the steam / water separator to the liquid phase part of the reactor containment vessel An exhaust pipe that discharges atmospheric gas separated by the steam separator to the outside, and the venturi nozzle and the steam separator are disposed inside the secondary containment facility and outside the reactor containment vessel. Installation It is.

  According to the embodiment of the present invention, it is possible to provide a compact filter vent facility, a filter vent method, and a nuclear power plant that do not require a large scrubber container or a water storage tank.

The block diagram of the filter vent equipment which concerns on 1st Embodiment. The block diagram of the filter vent equipment which concerns on 2nd Embodiment. The block diagram of the filter vent equipment which concerns on 3rd Embodiment. The block diagram of the filter vent equipment which concerns on 4th Embodiment. The block diagram of the filter vent equipment which concerns on 5th Embodiment. The block diagram of the filter vent equipment which concerns on 6th Embodiment. The block diagram of the filter vent equipment which concerns on 7th Embodiment. The block diagram of the filter vent equipment which concerns on 8th Embodiment. The block diagram of the filter vent equipment which concerns on 9th Embodiment.

Hereinafter, embodiments of a filter vent facility, a filter vent method, and a nuclear power plant according to the present invention will be described with reference to the drawings.
[First Embodiment]
The filter vent facility according to the first embodiment will be described with reference to FIG.

(Constitution)
As shown in FIG. 1, the filter vent facility according to the first embodiment includes a venturi nozzle 12 having a throttle portion 12a, a dry well 3 of a reactor containment vessel 2, and a gas phase portion of a suppression chamber 4 (“reactor Vent pipe 5 that connects the venturi nozzle 12 to the venturi nozzle 12, the liquid phase portion of the suppression chamber 4 (also referred to as “the liquid phase portion of the reactor containment vessel”) and the venturi nozzle 12. Nozzle pipe 13 connecting the throttle part 12a, steam-water separator 14, the pipe 8 connecting the venturi nozzle 12 and the steam-water separator 14, and the liquid phase part of the steam-water separator 14 and the suppression chamber 4 are checked. The return pipe 15 is connected via a valve 24, the exhaust pipe 6 is connected to the steam separator 14 and the outside, and the flow restriction orifice 16 is provided in the exhaust pipe 6. That.

(Function)
In the first embodiment configured as described above, when the internal pressure of the reactor containment vessel 2 rises due to an accident of the reactor or the like, the atmospheric gas containing the radioactive substance in the reactor containment vessel 2 passes through the vent pipe 5. It is led to the venturi nozzle 12 through. At that time, the water in the suppression chamber 4 is sucked into the throttle portion 12 a of the venturi nozzle 12 through the nozzle pipe 13 due to the venturi effect of the venturi nozzle 12. And the radioactive substance contained in atmospheric gas is transferred to water by the scrubbing effect which generate | occur | produces in the venturi nozzle 12. FIG.

  Next, the water (radiated water) containing the radioactive substance and the atmospheric gas are led to the steam separator 14 via the pipe 8 to separate the atmospheric gas and the activated water. The atmospheric gas separated by the steam separator 14 is discharged to the atmosphere via the exhaust pipe 6, and the activated water is returned to the suppression chamber 4 via the return pipe 15.

  The check valve 24 provided in the return pipe 15 is provided in order to prevent water from flowing back through the return pipe 15 during normal time (when not vented). Further, the flow restriction orifice 16 provided in the exhaust pipe 6 has a function of relaxing the fluctuation of the flow velocity of the atmospheric gas passing through the venturi nozzle 12 and maintaining the scrubbing effect and the venturi effect.

(effect)
As described above, according to the first embodiment, by supplying the water of the suppression chamber 4 to the venturi nozzle 12, the atmosphere gas in the reactor containment vessel 2 can be reduced without providing a scrubber vessel or a water storage tank. Venting can be performed.

Further, by circulating water through the steam separator 14 and the return pipe 15, the filter vent facility can be continuously operated. That is, in the conventional filter vent equipment, a scrubber container and a water storage tank that require water level adjustment are required. However, in this embodiment, it is necessary to collect water around the venturi nozzle 12 or to supply water by the water storage tank. Disappears. As a result, the filter vent facility can be downsized, and venting can be performed continuously without external water supply.
Furthermore, by using the high-temperature water of the suppression chamber 4, it is possible to prevent vapor condensation of the atmospheric gas and to mitigate an increase in hydrogen concentration.

[Second Embodiment]
A filter vent facility according to the second embodiment will be described with reference to FIG. In addition, the same code | symbol is attached | subjected to the same or similar structure as the said embodiment, and duplication description is abbreviate | omitted.

  In the second embodiment, the vent pipe 5 is branched, a plurality of venturi nozzles 12 are installed in parallel, and each venturi nozzle 12 is provided with a nozzle pipe communicating with the suppression chamber 4. Further, on the upstream side of each venturi nozzle 12, an on-off valve 7 (in the present embodiment, an electric valve) is provided.

In the second embodiment configured as described above, when a plurality of venturi nozzles 12 are installed in parallel, the pressure of the dry well 3 and the suppression chamber 4 decreases after venting, and the flow rate of the atmospheric gas decreases. By closing some open / close valves 7 among the plurality of venturi nozzles 12, the flow velocity at the venturi nozzle 12 with the open / close valves 7 open is increased, and the scrubbing effect and the venturi effect are maintained.
According to the present embodiment, in addition to the same effects as those of the first embodiment described above, the function of removing the radioactive substance can be maintained for a long time by the plurality of venturi nozzles 12.

[Third Embodiment]
A filter vent facility according to a third embodiment will be described with reference to FIG. In addition, the same code | symbol is attached | subjected to the same or similar structure as the said embodiment, and duplication description is abbreviate | omitted.
In the third embodiment, a safety valve 9 is provided on the upstream side of each venturi nozzle 12 in place of the on-off valve 7 and the flow restriction orifice 16 used in the second embodiment.

  In the third embodiment configured as described above, when the pressure of the dry well 3 and the suppression chamber 4 decreases after the venting and the flow rate of the atmospheric gas decreases, the safety valve 9 automatically maintains the flow rate of the atmospheric gas. And maintain the scrubbing effect and the venturi effect.

  More specifically, after venting, the pressure of the atmospheric gas in the reactor containment vessel 2 decreases, and as a result, some of the safety valves 9 are closed, and the venturi nozzle 12 connected to the opened safety valve 9 The flow rate of the atmospheric gas is maintained. When the pressure in the reactor containment vessel 2 decreases to such an extent that venting is unnecessary, all the safety valves 9 are closed.

  After venting, the pressure in the reactor containment vessel 2 basically decreases. However, if some or all of the safety valves 9 are closed and then the pressure rises again due to some event, the safety valve is closed. 9 opens again.

According to the present embodiment, the venting can be efficiently performed by the safety valve 9 having the same function and effect as the second embodiment described above and having an automatic flow rate maintaining function.
The safety valve 9 can also be applied to the above-described filter vent facility of the first embodiment.

[Fourth Embodiment]
A filter vent facility according to a fourth embodiment will be described with reference to FIG. In addition, the same code | symbol is attached | subjected to the same or similar structure as the said embodiment, and duplication description is abbreviate | omitted.

  In the fourth embodiment, the vent pipe 5, the nozzle pipe 13, the return pipe 15 and the exhaust pipe 6 are provided with on-off valves 25, and the test gas supply equipment 17 a and the test aerosol supply equipment 17 b are provided upstream of the venturi nozzle 12. A test water supply facility 17 c is provided in the nozzle pipe 13, a test recovery facility 17 d is provided in the exhaust pipe 6 connected to the steam separator 14, and a test wastewater treatment facility 17 e is provided in the return pipe 15. The configuration is provided.

  In the fourth embodiment configured as described above, the venturi nozzle 12 is configured by the test gas supply equipment 17a, the test aerosol supply equipment 17b, the test water supply equipment 17c, the test recovery equipment 17d, and the test wastewater treatment equipment 17e. Perform performance tests. At that time, each on-off valve 25 is appropriately opened and closed depending on the content and type of the performance test.

For example, when the performance test of the venturi nozzle 12 and the steam separator 14 is performed with the reactor containment vessel 2 side shut off, all the three on-off valves 25 in FIG. 4 are closed.
According to this embodiment, since various performance tests of the venturi nozzle 12 and the like can be performed as necessary, the reliability of the filter vent facility can be improved.

[Fifth Embodiment]
A filter vent facility according to a fifth embodiment will be described with reference to FIG. In addition, the same code | symbol is attached | subjected to the same or similar structure as the said embodiment, and duplication description is abbreviate | omitted.

(Constitution)
In the filter vent facility according to the fifth embodiment, the scrubber vessel 18 is disposed below the liquid level of the suppression chamber 4 (the liquid level of the liquid phase part of the reactor containment vessel). The venturi nozzle 12 is disposed in the scrubber vessel 18 and water from the suppression chamber 4 is supplied through the strainer 21 and the replenishing pipe 19 to keep a constant water level.

  The pipe 8 connected to the downstream side of the scrubber container 18 is provided with a steam / water separator 14, and the water separated by the steam / water separator 14 is returned to the scrubber container 18 by a return pipe 15 via a check valve 24. Returned to

  An electric water level adjustment valve 26 that operates in response to an electrical signal (measured value) from the water level gauge 20a, a steam separator 14 and a scrubber vessel 18 are connected to the supply pipe 19 via a check valve 24. A return pipe 15 is provided. The water level gauge 20a measures the water level in the scrubber container 18.

(Function)
In the fifth embodiment configured as described above, when the water level gauge 20a detects a decrease in the water level of the scrubber vessel 18, the water in the suppression chamber 4 is supplied through the supply pipe 19 by opening the water level adjustment valve 26. The water level is controlled by supplying to the scrubber container 18.

(effect)
According to this embodiment, since the water level of the scrubber container 18 can be controlled using the water of the suppression chamber 4 without any external water supply such as a water storage tank, the venting can be continued for a long time. It becomes possible.

[Sixth Embodiment]
A filter vent facility according to the sixth embodiment will be described with reference to FIG. In addition, the same code | symbol is attached | subjected to the same or similar structure as the said embodiment, and duplication description is abbreviate | omitted.
In the present embodiment, a level switch 20b is provided instead of the water level gauge 20a described in the fifth embodiment, and the water level adjusting valve 26 is mechanically interlocked.

  In the present embodiment configured as described above, the level switch 20b for detecting the water level is installed, the water level adjusting valve 26 is automatically opened and closed according to the water level, and the scrubber vessel 18 is replenished with water.

  According to this embodiment, in addition to the same effects as the fifth embodiment described above, the level switch 20b can be used to automatically control the water level without using electricity. It becomes possible to do.

[Seventh Embodiment]
A filter vent facility according to the seventh embodiment will be described with reference to FIG. In addition, the same code | symbol is attached | subjected to the same or similar structure as the said embodiment, and duplication description is abbreviate | omitted.
In the present embodiment, a spray head 27 is used instead of the venturi nozzle 12 described in the fifth and sixth embodiments.

In the seventh embodiment configured as described above, the radioactive substance is transferred from the atmospheric gas to water by the spray head 27 in the same manner as the venturi nozzle 12.
In the case of the spray type, since the spray head 27 is disposed at a certain level below the liquid level, it is necessary to maintain the water level at a predetermined height.

  In the scrubber container 18 described in the fifth or sixth embodiment, the water inside the scrubber container 18 is maintained at a constant water level. Therefore, in the seventh embodiment, the venturi nozzle 12 is replaced with the spray head 27, and the fifth And while having the effect similar to 6th Embodiment, the structure of the scrubber container 18 can be simplified by using the general purpose spray head 27. FIG.

[Eighth Embodiment]
A filter vent facility according to the eighth embodiment will be described with reference to FIG. In addition, the same code | symbol is attached | subjected to the same or similar structure as the said embodiment, and duplication description is abbreviate | omitted.

  In the eighth embodiment, a metal fiber filter 22 is disposed between the steam separator 14 and the flow restriction orifice 16, and an iodine removal filter 23 is provided on the downstream side of the flow restriction orifice 16.

  In the eighth embodiment configured as described above, a minute radioactive material that cannot be removed by the venturi nozzle 12 is removed by installing the metal fiber filter 22 between the steam separator 14 and the flow restriction orifice 16.

  Further, by adjusting the flow rate of the atmospheric gas by the flow restriction orifice 16, radioactive iodine that cannot be removed by the venturi nozzle 12 or the metal fiber filter 22 is removed by the iodine removal filter 23.

  According to the present embodiment, in addition to the same effects as the above-described embodiment, by installing the metal fiber filter 22 and the iodine removal filter 23, the minute radioactive substance that cannot be removed by the venturi nozzle 12 is removed. Is possible.

[Ninth Embodiment]
A filter vent facility in a nuclear power plant according to the ninth embodiment will be described with reference to FIG. In addition, the same code | symbol is attached | subjected to the same or similar structure as the said embodiment, and duplication description is abbreviate | omitted.

  In the filter vent facility according to the ninth embodiment, the venturi nozzle 12, the steam separator 14, and the flow restriction orifice 16 in the configuration of the first embodiment are provided in the secondary storage facility 40 of the reactor building. . The secondary containment facility 40 here is a nuclear power plant facility that is located inside the reactor building 30 and is hermetically configured to contain the reactor containment vessel 2.

  Since conventional filter vent equipment requires a large installation space, it has been installed in underground pits outside the reactor building. In contrast, the filter vent facility of the first embodiment, which is smaller than the conventional one, can be installed near the suppression chamber or in a space such as a gap between the existing device and the device as shown in the present embodiment. it can. Since the venturi nozzle 12 and the steam separator 14 are installed in the secondary containment facility 40 and the removal of the aerosol-like radioactive material is carried out in the secondary containment facility 40 of the reactor building, the aerosol-like radioactive material Release from the secondary storage facility 40 to the outside can be prevented.

  The flow restriction orifice 16 may be outside the secondary storage facility 40. Moreover, it is applicable also to the filter vent equipment after 2nd Embodiment. At this time, for example, some devices such as the test gas supply facility 17 a of the fourth embodiment may be installed outside the secondary storage facility 40.

  As mentioned above, although several embodiment of this invention was described, these embodiment is shown as an example and is not intending limiting the range of invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

2 ... Primary containment vessel, 3 ... Dry well, 4 ... Suppression chamber, 5 ... Vent piping, 6 ... Exhaust piping, 7 ... Open / close valve (motor valve), 8 ... Piping, 9 ... Safety valve, 12 ... Venturi nozzle, 13 DESCRIPTION OF SYMBOLS ... Nozzle piping, 14 ... Air-water separator, 15 ... Return piping, 16 ... Flow restriction orifice, 17a ... Test gas supply equipment, 17b ... Test aerosol supply equipment, 17c ... Test water supply equipment, 17d ... Test recovery Equipment, 17e ... Waste water treatment facility for testing, 18 ... Scrubber container, 19 ... Supply pipe, 20a ... Water level gauge, 20b ... Level switch, 21 ... Strainer, 22 ... Metal fiber filter, 23 ... Iodine removal filter, 24 ... Reverse Stop valve, 25 ... Open / close valve, 26 ... Water level adjustment valve, 27 ... Spray head, 30 ... Reactor building, 40 ... Secondary containment facility

Claims (9)

In the filter vent facility that processes the atmospheric gas inside the reactor containment vessel,
A venturi nozzle, a vent pipe connecting the gas phase part of the reactor containment vessel and the venturi nozzle, a nozzle pipe connecting the liquid phase part of the reactor containment vessel and the throttle part of the venturi nozzle, and the venturi nozzle A steam / water separator provided downstream, a return pipe for returning water separated by the steam / water separator to the liquid phase part of the reactor containment vessel, and an atmospheric gas separated by the steam / water separator Filter vent equipment equipped with exhaust piping that discharges water outdoors.   2. The filter vent facility according to claim 1, wherein a plurality of the venturi nozzles are provided in parallel, and an on-off valve is provided upstream of each venturi nozzle.   2. The filter vent facility according to claim 1, wherein a plurality of the venturi nozzles are provided in parallel, and a safety valve capable of adjusting a flow rate of the atmospheric gas is provided upstream of each venturi nozzle.   A test gas supply facility and a test aerosol supply facility are connected to the vent pipe, a test water supply facility is connected to the nozzle pipe, a test recovery facility is connected to the exhaust pipe, and a test wastewater is connected to the return pipe. The filter vent equipment according to any one of claims 1 to 3, wherein a processing facility is connected. In the filter vent facility that processes the atmospheric gas inside the reactor containment vessel,
A scrubber vessel disposed below the liquid level of the liquid phase portion of the reactor containment vessel; a venturi nozzle provided in the scrubber vessel; a water level meter for measuring the water level of the scrubber vessel; and the reactor A vent pipe connecting the gas phase part of the containment vessel and the venturi nozzle, a replenishment pipe connecting the liquid phase part of the reactor containment vessel and the scrubber vessel, and a measured value of the water level meter provided in the replenishment pipe A water level adjusting valve that is opened and closed in response, a steam / water separator provided on the downstream side of the scrubber container, a return pipe for returning water separated by the steam / water separator to the scrubber container, and the steam water An exhaust pipe that discharges atmospheric gas separated by the separator to the outside, and a filter vent facility.   6. A filter vent facility according to claim 5, wherein a spray head is provided in place of the venturi nozzle.   The filter vent facility according to claim 5 or 6, wherein a level switch for detecting the water level of the scrubber container is provided instead of the water level gauge, and the water level adjusting valve is opened and closed according to the operation of the level switch. Guiding the atmosphere gas of the reactor containment vessel to the venturi nozzle to cause the liquid phase portion of the reactor containment vessel to be sucked into the throttle portion of the venturi nozzle and scrubbing the atmosphere gas; and
A step of separating the mixed gas of the atmospheric gas and water after the scrubbing step into air and water;
Releasing the atmospheric gas after the air-water separation into the atmosphere;
Returning the water after the gas-water separation to the liquid phase part of the reactor containment vessel. The reactor building,
A secondary containment facility enclosed in the reactor building and configured to be airtight;
A reactor containment vessel contained in the secondary containment facility and having a liquid phase part in which water is stored;
A venturi nozzle,
A vent pipe connecting the gas phase part of the containment vessel and the venturi nozzle;
A nozzle pipe connecting the liquid phase part of the reactor containment vessel and the throttle part of the venturi nozzle;
A steam separator provided downstream of the venturi nozzle;
A return pipe for returning the water separated by the steam separator to the liquid phase part of the reactor containment vessel;
An exhaust pipe for discharging the atmospheric gas separated by the steam separator to the outside;
A nuclear power plant in which the venturi nozzle and the steam separator are installed inside the secondary containment facility and outside the reactor containment vessel.

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