JP2011133315A - Cooling structure of reactor containment vessel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce a size of a nuclear plant and to reduce its cost, and to provide reliable cooling structure of a reactor containment vessel utilizing passive drive force by reducing or omitting volume of an upper cooling water storage tank installed at an upper portion of the reactor containment vessel. <P>SOLUTION: The cooling structure of a reactor containment vessel includes: an annular air passage 4 surrounding an outer peripheral surface of the reactor containment vessel 2; a side face cooling water storage tank 8 disposed at an outer periphery of the air passage 4; an annular gutter 10 provided on an outer peripheral surface of the containment vessel 3; a flow-down hole 12 provided at the bottom of the gutter 10; and a plurality of water supply ducts 9 for supplying cooling water of the side face cooling water storage tank 8 to the gutter 10. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a reactor containment cooling structure, and more particularly to a reactor containment cooling structure using passive driving force.

  In the nuclear power plant, when the coolant is discharged into the reactor containment vessel due to pipe breakage or the like, the coolant becomes high-temperature steam due to decompression, and thus the pressure in the reactor containment vessel increases. Conventionally, in order to suppress the pressure rise and ensure the soundness of the containment vessel, the generated steam is guided to the pressure suppression pool in the containment vessel to condense, or the upper part of the containment vessel is sprayed into the containment vessel spray to A method for condensing the water is known. In these methods, heat accumulated in the pressure suppression pool and spray water is finally released to the outside through a heat exchanger by a dynamic device such as a pump.

  In recent years, in order to improve the reliability of the safety system, the pressure suppression method inside the containment vessel is not a dynamic device as in the past, but the natural passive force such as gravity is used as the driving force for the containment vessel. A method of removing heat has been proposed (Patent Document 1).

  FIG. 10 shows a specific example. Between the containment vessel 2 containing the reactor pressure vessel 1 and the reactor building 3, there is an annular air passage 4 surrounding the containment vessel 2, and the coolant is discharged into the containment vessel 2 so that the pressure and temperature are increased. Is raised, the air flowing in from the lower part of the air flow path 4 is heated from the surface of the containment vessel 2 and is exhausted from the chimney 5 at the upper part of the containment vessel due to the chimney effect while removing the heat.

  Further, an upper cooling water storage tank 6 is provided at the upper part of the containment vessel 2, and water is sprinkled from the upper sprinkling pipe 7 communicating with the tank 6 to the upper surface of the containment vessel. The water evaporates by heat transfer from the wall surface in the process of flowing down the outer peripheral side surface of the containment vessel 2 as it is due to gravity, and rises along the annular flow path 4 together with the air and is discharged from the chimney 5. With these effects, the inside of the storage container 2 can be cooled and decompressed without using a dynamic device.

Japanese Patent No. 2813412

  As described above, when water is sprinkled on the upper surface of the containment vessel 2 by gravity to remove heat from the containment vessel, it is not necessary to consider the failure of the drive device because the power device is not used. On the other hand, in order to use gravity, it is necessary to install the upper cooling water storage tank 6 on the upper part of the containment vessel, and there is a problem that the overall height of the reactor building 3 increases and the center of gravity increases.

  In particular, in a plant having a large reactor output, the containment vessel 2 and the upper cooling water storage tank 6 are enlarged in order to secure a necessary heat removal amount, leading to an increase in the size of the entire reactor building 3. On the other hand, from the viewpoint of seismic design and construction cost, it is desirable to make the plant building height and center of gravity as low as possible.

  The present invention has been made to solve the above-mentioned problems, and by reducing or omitting the volume of the upper cooling water storage tank installed in the upper part of the reactor containment vessel, the nuclear power plant can be reduced in size and cost. An object of the present invention is to provide a highly reliable reactor containment cooling structure using passive driving force.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and a reactor containment vessel cooling structure according to the present invention comprises an annular air flow path surrounding the outer peripheral surface of the nuclear reactor containment vessel, and an outer periphery of the air flow path. The side cooling water storage tank disposed on the outer periphery of the containment vessel, an annular trough provided on the outer peripheral surface of the containment vessel, a flow hole provided in the bottom of the trough, and the cooling water in the side cooling water storage tank are provided in the trough. And a plurality of water distribution ducts for distributing water.
Further, the present invention is characterized in that a plurality of stages of the reactor containment cooling structure according to the present invention are provided in the height direction of the containment vessel.

  According to the present invention, it is possible to reduce the size and cost of the nuclear power plant by reducing or omitting the volume of the upper cooling water storage tank installed on the upper part of the reactor containment vessel, and passively. It is possible to provide a highly reliable reactor containment cooling structure using driving force.

The whole block diagram of the cooling structure of the nuclear reactor containment vessel concerning the 1st Embodiment of this invention. FIG. 2 is a view taken along the line A-A ′ of FIG. 1. The partial notch figure of the scissors which concern on the 1st Embodiment of this invention. The modification of the cooling structure of the reactor containment vessel which concerns on the 1st Embodiment of this invention. The whole block diagram of the cooling structure of the nuclear reactor containment vessel which concerns on the 2nd Embodiment of this invention. The expanded sectional view of the bag which concerns on the 3rd Embodiment of this invention. The cross-sectional view of the reactor containment cooling structure according to the fourth embodiment of the present invention. The whole block diagram of the cooling structure of the reactor containment vessel which concerns on the 5th Embodiment of this invention. The upper part enlarged view of the cooling structure of the nuclear reactor containment vessel which concerns on the 5th Embodiment of this invention. The whole block diagram of the cooling structure of the conventional reactor containment vessel.

  Hereinafter, an embodiment of a reactor containment cooling structure according to the present invention will be described with reference to the drawings.

(First embodiment)
A reactor containment cooling structure according to a first embodiment of the present invention will be described with reference to FIGS.
FIG. 1 is an overall configuration diagram of a reactor containment cooling structure according to a first embodiment of the present invention, and FIG. 2 is an AA cross-sectional view thereof. In FIG. 1 and FIG. 2, a side cooling water storage tank 8 is provided so as to surround the outer side of the annular air flow path 4 that surrounds the outer periphery of the storage container 2. As shown in FIG. 2, the side cooling water storage tank 8 is composed of one annular tank or a plurality of divided annular tanks (not shown) surrounding the entire circumference.

  A water distribution duct 9 is connected to the side cooling water storage tank 8 at regular intervals in the circumferential direction, and its tip extends to the top of an annular trough 10 installed on the outer peripheral surface of the containment vessel. Further, as shown in FIG. 3, flow-down holes 12 are provided at the bottom of the tub 10 at predetermined intervals along the circumferential direction at the joint between the tub 10 and the storage container 2.

  In the reactor containment vessel cooling structure configured as described above, when high-temperature steam is released into the containment vessel 2 and pressure reduction is required, it is caused by gravity from the side cooling water storage tank 8 through the water distribution duct 9. Pour cooling water into the bowl 10. The cooling water that has flowed into the tub 10 flows down the outer peripheral surface of the storage container 2 through the flow-down hole 12 provided in the joint surface between the storage container 2 and the tub 10.

  At this time, since the flow-down hole 12 is provided so as to contact the outer peripheral surface of the storage container 2, the cooling water that has passed through the flow-down hole 12 flows down while contacting the outer peripheral surface of the storage container. The cooling water evaporates by heat transfer from the containment vessel 2 in the process of flowing down the outer peripheral surface, and ascends the air flow path 4 as indicated by an arrow 11 and is exhausted from the chimney 5 to the outside. In addition, by providing the plurality of flow-down holes 12 at the bottom of the bowl 10 so as to contact the outer peripheral surface of the storage container 2, the entire outer peripheral surface of the storage container is uniformly cooled.

  In addition, as shown in FIG. 4, when the storage container 2 has a shape in which the diameter changes in the height direction and becomes larger as the position is lower, the tip of the water distribution duct 9 is located above the position where the diameter changes. By arranging such that the cooling water flowing out can be sprinkled on the side surface of the storage container without providing a structure such as the eaves 10 and the flow-down hole 12 on the outer peripheral surface of the storage container.

  According to the first embodiment, the cooling water source required to remove heat from the side surface of the storage container 2 is the side surface cooling water storage tank 8, so that the upper cooling water storage tank 6 moves to the upper surface of the storage container 2. Since the cooling water to be injected needs only to secure an amount necessary for cooling only the upper surface, the volume of the upper cooling water storage tank can be reduced and the height and center of gravity of the building can be lowered. Therefore, it is possible to provide an efficient and highly reliable cooling structure for a containment vessel using a passive driving force.

(Second Embodiment)
A reactor containment cooling structure according to a second embodiment of the present invention will be described with reference to FIG.
The second embodiment is characterized in that a plurality of cooling structures including the side cooling water storage tank 8 and the corresponding basket 10 are provided in accordance with the height of the containment vessel 2.

  FIG. 5 shows an example in which the cooling structure is arranged in two stages. In the building 3 on the outer periphery of the reactor containment vessel 2, the upper side cooling water storage tank 8 a, the water distribution duct 9 a, the eaves 10 a, and the lower side cooling water storage tank. 8b, a water distribution duct 9b, and a gutter 10b are provided. In this case, it is desirable to provide the lower ridge 10b below the position where the cooling water film flowing down from the upper ridge 10a and forming on the outer peripheral surface of the storage container 2 disappears due to evaporation.

According to the second embodiment, by providing a plurality of cooling structures including the side cooling water storage tank 8 and the eaves 10 in the height direction of the containment vessel, the outer circumference of the containment vessel and the overall length in the height direction are provided. Therefore, the height and center of gravity of the building can be further reduced.
In addition, although this embodiment demonstrated the example which has arrange | positioned 2 steps | paragraphs of cooling structures, it is not limited to it, For example, you may arrange | position 3 steps | paragraphs or more.

(Third embodiment)
A reactor containment cooling structure according to a third embodiment of the present invention will be described with reference to FIG.
In the present embodiment, in order to reliably form the cooling water film 13 on the outer peripheral surface of the storage container 2, the flow-down hole 12 provided in the bottom of the tub 10 is shaped so as to be narrowed toward the storage container as it approaches the outlet. .
In addition, a weir 14 is provided in the height direction of the eaves 10 around the inlet of the downflow hole 12.

In the cooling structure configured in this manner, the cooling water that has flowed into the dredging 10 from the water distribution duct 9 once accumulates in the dredging 10, and starts to flow down the downhole 12 beyond the weir after the water level reaches the height of the weir 14. Therefore, the amount of cooling water flowing down from the plurality of flow holes 12 in the circumferential direction becomes equal, the amount of heat removed from the outer peripheral surface of the containment vessel 2 is equalized in the circumferential direction, and the temperature distribution of the containment vessel becomes uneven. To prevent.
According to the third embodiment, since the bag is configured as described above, it is possible to uniformly and efficiently cool the entire outer peripheral surface of the storage container.

(Fourth embodiment)
A reactor containment cooling structure according to a fourth embodiment of the present invention will be described with reference to FIG.
In the present embodiment, a flow control valve 15 is provided in a plurality of water distribution ducts 9 arranged in the circumferential direction, and a thermometer 16 is installed on the inner peripheral side of the containment vessel 2 corresponding to the installation position of the water distribution duct 9.

  The trough 10 at the lower part of the outlet of the water distribution duct 9 is partitioned in the circumferential direction by a partition plate 17 at a predetermined interval, and the containment container 2 through the water level in each section of the trough 10 and the downhole 12 from the trough 10. The amount of water flowing through the side surface of the water can be adjusted by the amount of cooling water flowing from the water distribution duct 9 corresponding to the section.

  In the cooling structure configured as described above, when the containment vessel cooling system is operating, the opening degree of the flow rate adjusting valve 15 provided in each water distribution duct 9 is adjusted based on the detection value of the thermometer 16. That is, when the detected value of the thermometer 16 at a certain location shows a higher value than the others, the opening degree of the flow control valve 15 of the corresponding water distribution duct 9 is made larger than the others, so that The amount of cooling water flowing down the inflow amount and the side surface can be increased, and the amount of heat removal at the location can be improved.

  According to the fourth embodiment, the cage is partitioned in the circumferential direction, and each distribution duct is provided with a flow control valve and a thermometer in the containment vessel, so that the outer peripheral surface of the containment vessel is in accordance with the temperature distribution of the containment vessel. More uniformly and efficiently.

(Fifth embodiment)
A reactor containment cooling structure according to a fifth embodiment of the present invention will be described with reference to FIGS.

  In this embodiment, the cooling air flow path 18 is provided in the outer peripheral part of the area where the air flow path 4 passes the upper part of the storage container. The inlet 19 of the cooling air passage 18 is installed on the outer side surface of the reactor building 3, and the height of the outlet 20 is equal to the height of the chimney 5 corresponding to the outlet of the air passage 4. To do. Thereby, the air flow path in the upper part of the containment vessel 2 is duplexed into the air flow path 4 continuing from the outer peripheral surface of the containment vessel 2 and the cooling air flow path 18 flowing in the vicinity of the reactor building 3 in the upper part of the containment vessel 2. Is done.

  Further, the partition wall 21 between the cooling air flow path 18 and the air flow path 4 is made of a metal or the like having good thermal conductivity, and the surface is provided with cooling fins 22 extending vertically downward as shown in FIG. Also good.

  In the cooling structure configured as described above, when the containment vessel cooling system is operating, the cooling water flowing down the outer peripheral surface of the containment vessel 2 from the side cooling water storage tank 8 through the eaves 10 and the flow-down holes 12 is stored. It receives heat from the container and gradually evaporates, and ascends the air flow path 4 with air as water vapor. When the rising air and steam reach the upper part of the containment vessel 2, a part of the water vapor 23 is condensed on the partition wall 21 due to heat exchange with the airflow flowing through the cooling air flow path 18, and the water droplets 23 adhere. These fall to the upper surface of the storage container 2 through the fins 22 provided on the partition wall 21. The dropped water drop 23 takes heat from the storage container 2 and evaporates again. Thereby, even when the upper cooling water storage tank used for cooling the upper surface of the storage container is not installed at the upper part, the upper surface of the storage container 2 is covered with the cooling water, and heat can be removed by the latent heat.

  According to the fifth embodiment, by doubling the cooling structure of the containment vessel, the cooling upper cooling water storage tank above the containment vessel can be omitted, and the upper surface and outer peripheral surface of the containment vessel can be efficiently cooled. Therefore, the height and center of gravity of the building can be further reduced.

  As mentioned above, although embodiment of the cooling structure of the containment vessel concerning this invention was described, this invention is not limited to this, You may comprise the cooling structure of a containment vessel suitably combining these.

DESCRIPTION OF SYMBOLS 1 ... Reactor pressure vessel, 2 ... Containment vessel, 3 ... Reactor building, 4 ... Air flow path, 5 ... Chimney, 6 ... Upper cooling water storage tank, 7 ... Upper water spray pipe, 8 ... Side cooling water storage tank, DESCRIPTION OF SYMBOLS 9 ... Water distribution duct, 10 ... Soot, 12 ... Downflow hole, 13 ... Cooling water film, 14 ... Weir, 15 ... Flow control valve, 16 ... Thermometer, 17 ... Partition plate, 18 ... Cooling air flow path, 19 ... Cooling Air channel inlet, 20 ... cooling air channel outlet, 21 ... partition, 22 ... fin, 23 ... water droplet.

Claims (10)

  An annular air passage surrounding the outer peripheral surface of the reactor containment vessel, a side cooling water storage tank disposed on the outer periphery of the air passage, an annular trough provided on the outer peripheral surface of the containment vessel, and A reactor containment vessel cooling structure comprising a down hole provided in a bottom portion and a plurality of water distribution ducts for distributing cooling water of the side surface cooling water storage tank to the trough.   2. The reactor containment vessel cooling structure according to claim 1, wherein the side cooling water storage tank is an annular storage tank or an annular storage tank divided into a plurality of parts.   3. The reactor containment vessel cooling structure according to claim 1, wherein the flow-down hole is provided in contact with an outer peripheral surface of the containment vessel.   The reactor containment vessel cooling structure according to claim 3, wherein a weir is provided on the side of the containment vessel of the dredger and around the downflow hole.   The reactor containment vessel cooling structure according to claim 4, wherein the downflow hole has a shape that is narrowed toward the containment vessel as it approaches the outflow port.   5. The reactor containment vessel cooling structure according to claim 1, wherein the annular dredger is divided into a plurality of compartments, and a flow control valve is provided in the water distribution duct arranged in each compartment. .   The reactor according to claim 6, wherein a thermometer is provided on the inner peripheral surface of the containment vessel corresponding to the section, and the opening degree of the flow control valve is adjusted based on a detection value of the thermometer. Containment container cooling structure.   8. A reactor containment vessel cooling structure according to claim 1, wherein the reactor containment vessel cooling structure according to any one of claims 1 to 7 is provided in a plurality of stages in a height direction of the containment vessel.   9. The reactor containment vessel cooling structure according to claim 1, wherein a cooling air passage is provided on an outer periphery of a partition wall of an air passage above the reactor containment vessel.   The reactor containment vessel cooling structure according to claim 9, wherein the partition wall is provided with cooling fins toward an upper surface of the containment vessel.

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