KR101535479B1 - Depressurization system of reactor coolant system and nuclear power plant having the same - Google Patents

Abstract

A depressurization system of a reactor coolant system according to an embodiment of the present invention comprises: a pressurization unit to maintain a reactor coolant system at a constant pressure; and a depressurization unit to decrease the pressure of the reactor coolant system when the pressure of the reactor is higher than or equal to the reference pressure. The depressurization unit comprises: a condensation unit to receive steam from the pressurization unit and condense the steam to prevent a coolant loss accident where the coolant is discharged outside the pressurization unit when the depressurization unit is opened; and a storage unit with internal space to store condensed liquid condensed by the condensation unit, which is set below the condensation unit to receive the condensed liquid by head pressure as well as by pressure difference.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a nuclear reactor coolant system decompression system,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a nuclear reactor coolant system depressurization system for preventing the occurrence of a coolant loss accident caused by opening of a nuclear reactor coolant system decompression system and a nuclear power plant having the same.

A reactor is a separate reactor (eg, a domestic pressurized light water reactor) in which major equipment (steam generator, pressurizer, pump impeller, etc.) is installed outside the reactor depending on the installation location of the main equipment and an integrated reactor in which the main equipment is installed inside the reactor vessel , SMART reactor).

In addition, reactors are divided into active reactors and passive reactors depending on how safety systems are implemented. An active reactor is a reactor that uses active equipment such as a pump operated by an electric power such as an emergency generator to drive the safety system. The passive reactor is operated by gravity or gas pressure to drive the safety system It is a reactor that uses passive devices.

Passive safety systems in passive reactors are built into the system without an AC power source such as an operator action or emergency diesel generator for more than the time (72 hours) required by regulatory requirements in the event of an accident. It is a system in which the reactor is safely maintained only by its natural force, and after 72 hours, the safety system can be assisted by a driver action or a non-safety system.

The reactor coolant system depressurization facility is generally installed above the pressurizer and is installed to prevent overpressure of the reactor coolant system when the pressure in the reactor coolant system increases.

Generally, the downstream end of the decompression facility is configured to be discharged into the reactor drainage tank, the rupture disc, the containment vessel internal storage tank, or the internal atmosphere of the containment building. Therefore, if the decompression facility is continuously operated, it will develop into a coolant loss accident. The loss of coolant is a radioactive material contained in the reactor coolant that is released, which causes most of the equipment exposed to the environment inside the containment building to be polluted, making it difficult to follow up after the accident.

Accordingly, the development of a pressure reducing facility configured to prevent the loss of a non-coolant loss from being spread to a coolant loss accident can be considered.

1. Japanese Unexamined Patent Application Publication No. 2012-233711 (November 29, 2012) 2. Korean Patent Registration No. 10-1172901 (Aug. 20, 2012) 3. JP-A-07-253492 (April, 2003)

The present invention provides a nuclear reactor coolant system depressurization system for preventing an open accident of a decompression system due to overpressure of a reactor coolant system from spreading to a coolant loss accident, and a nuclear power plant having the same.

To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described herein, there is provided a system for reducing pressure in a nuclear reactor coolant system, comprising: a pressure unit for maintaining a pressure of a reactor coolant system constant; Wherein the pressure reducing unit is configured to receive steam from the pressurizing unit to prevent a loss of a coolant generated outside the pressurizing unit when the pressure reducing unit is opened, A condenser for condensing the steam, and an internal space for storing the condensed water condensed in the condenser, and a receiver disposed below the condenser to receive the condensed water by the head and pressure difference.

According to one example of the present invention, the reactor coolant system decompression system further includes an injection pipe connected between the accommodating portion and the reactor coolant system, and the injection pipe is connected between the decompression portion and the reactor coolant system And the condensed water in the receiving portion may be supplied to the reactor coolant system by the head difference if the pressure of the decompression portion and the reactor coolant system is changed to an equilibrium state in order to circulate the condensed water and remove the residual heat of the reactor coolant system .

The injection piping may be connected to a safety injection system for injecting a coolant into the reactor coolant system in the event of an accident.

The injection piping may be formed to extend from a lower portion of the accommodating portion to be connected to the reactor coolant system.

According to another embodiment of the present invention, the nuclear reactor coolant system decompression system further includes a cooling water storage unit configured to store cooling water therein, wherein the condensed water is condensed by the cooling water, So as to be immersed in the cooling water stored in the cooling water storage part.

The cooling water reservoir may be configured to recover the condensed condensed water by a compartment cooling system disposed inside the compartment and condensing the vapor inside the compartment to lower the pressure.

The cooling water storage unit may be configured to recover the coolant that is disposed inside the compartment and spills into the compartment by the compartment watering system in the event of an accident.

The coolant storage unit may be configured to supply the coolant to the safety injection system for injecting the coolant into the reactor coolant system in the event of an accident.

According to another embodiment of the present invention, the nuclear reactor coolant system decompression system further includes a cooling water storage unit configured to store cooling water therein, wherein the cooling water storage unit is disposed outside the compartment, And the cooling water stored in the cooling water storage part can be moved to the condenser part by the difference in the water level and the density generated between the condensation part and the cooling water storage part.

According to another embodiment of the present invention, the reactor coolant system decompression system is connected to the pressurizing unit and the condensing unit, respectively, so as to transfer steam generated outside the pressurizing unit to the condensing unit when the decompressing unit is opened And may further include at least one pressure reducing pipe.

The pressure reducing pipe may include at least one safety discharge valve installed to selectively open and close the flow path according to whether the pressure of the reactor coolant system rises above a reference pressure.

The decompression pipe includes a first decompression pipe connected to the pressurizing unit and an upper portion of the condensing unit to transfer steam generated outside the pressurizing unit to the condensing unit when the decompression unit is opened, And at least one second pressure reducing pipe connected to the pressurizing unit.

Wherein the first pressure reducing pipe is opened when the pressure of the reactor coolant system rises above a reference pressure and is closed when the pressure of the reactor coolant system falls below a reference pressure, The second pressure reducing pipe may include at least one safety reducing valve selectively installed to open and close the flow path depending on whether the pressure of the reactor coolant system rises above a reference pressure.

The first pressure reducing pipe may include at least one pressurizing portion safety valve that is opened when the pressure of the reactor coolant system rises above a reference pressure and is closed when the pressure of the reactor coolant system falls below a reference pressure And the second pressure reducing pipe may include at least one automatic pressure reducing valve installed to open when the pressure of the reactor coolant system rises above a reference pressure.

According to another aspect of the present invention, there is provided a nuclear reactor coolant system depressurizing system, comprising: a flow path formed between the pressurizing portion and a condensing portion; a flow path formed between the condensing portion and the accommodating portion; And a rupture plate installed to lower the pressure when the pressure rises above a predetermined pressure.

According to another aspect of the present invention, there is provided a nuclear reactor coolant system depressurizing system, comprising: a flow path formed between the pressurizing portion and a condensing portion; a flow path formed between the condensing portion and the accommodating portion; And an atmospheric release valve installed to selectively open and close the passage when the pressure rises above a predetermined pressure.

The condenser may be formed of at least one plate heat exchanger having a plurality of flow channel channels.

The plate heat exchanger may include a flow path resistance portion for generating a resistance to the flow of the cooling water so as to stabilize the flow of the cooling water stored in the cooling water storage portion.

In addition, the plate heat exchanger may be formed such that the flow path of the cooling water is entirely opened to smooth the flow of the cooling water stored in the cooling water storage part.

According to another aspect of the present invention, there is provided an exhaust gas recirculation system comprising: an exhaust pipe branched from the accommodating portion and connected to the interior of the reactor coolant system; and an exhaust pipe extending from the accommodating portion to the non- And may further include an exhaust valve.

Also, in order to realize the above-mentioned problem, the present invention proposes a nuclear power plant having a nuclear reactor coolant system decompression system.

The nuclear power plant includes a reactor coolant system, a compartment for enclosing the reactor coolant system to prevent leakage of radioactive material at the time of an accident, and a coolant or steam discharged from the reactor coolant system or the secondary system at the time of accident, A pressure reducing system for suppressing an increase in pressure of the reactor coolant system; a pressure reducing unit for maintaining a pressure of the reactor coolant system at a constant level; Wherein the pressure reducing unit is configured to receive steam from the pressurizing unit to prevent a loss of a coolant generated outside the pressurizing unit when the pressure reducing unit is opened, A condenser for condensing the vapor, Having an internal space for storing the condensed water condensed in the condensing section, and to receive the condensate passes by the head, and the pressure difference includes a receiving portion disposed under the condensing part.

The reactor coolant system depressurization system according to the present invention and the effect of a nuclear power plant having the same will now be described.

According to at least one of the embodiments of the present invention, the decompression unit configured to lower the pressure of the reactor coolant system when the pressure of the reactor coolant system rises above the reference pressure includes a condenser for condensing the vapor generated in the compression unit, And a receiving portion formed to receive and receive the condensed condensed water in the condensing portion. According to the configuration of the decompression unit, there is an advantage that the loss of the coolant loss that may occur when the decompression unit operates can be basically eliminated.

According to at least one of the embodiments of the present invention, as the pressure in the decompression portion and the reactor coolant system is changed to an equilibrium state, the condensed water in the accommodating portion is condensed by the water coolant system So that the decompression of the reactor coolant system and the removal of the residual heat can be effectively performed.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1A is a conceptual diagram showing a nuclear reactor coolant system depressurization system according to an embodiment of the present invention and a normal operation of a nuclear power plant having the same. FIG.
FIG. 1B is a conceptual diagram showing a state in which the pressurizing portion safety valve shown in FIG. 1A is opened. FIG.
Fig. 1C is a conceptual diagram showing the opening early stage of the safety reducing valve shown in Fig. 1A. Fig.
FIG. 1D is a conceptual view showing the second half of the safety reducing valve shown in FIG. 1A; FIG.
FIG. 2 is a conceptual diagram showing a nuclear reactor coolant system depressurization system according to another embodiment of the present invention, and a nuclear power plant having the same. FIG.
FIG. 3 is a conceptual diagram showing a nuclear reactor coolant system depressurization system according to another embodiment of the present invention and a normal operation of a nuclear power plant having the same.
4A to 4H are schematic diagrams showing a nuclear reactor coolant system depressurization system according to another embodiment of the present invention and a normal operation of a nuclear power plant having the same.
FIG. 5 is a conceptual diagram showing an example in which the condensing portion shown in FIG. 1A is formed by a plurality of heat exchangers. FIG.
6A to 6C are conceptual diagrams showing examples in which the condenser shown in FIG. 1A is formed by a plate heat exchanger.
FIG. 7 is a conceptual view showing an example of a flow path formed between the condensing portion and the pressurizing portion shown in FIG. 1A; FIG.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a nuclear reactor coolant system depressurization system and a nuclear power plant having the nuclear reactor coolant system of the present invention will be described in detail with reference to the accompanying drawings.

In the present specification, the same or similar reference numerals are given to different embodiments in the same or similar configurations. As used herein, the singular forms "a", "an" and "the" include plural referents unless the context clearly dictates otherwise.

FIG. 1A is a conceptual view showing a nuclear reactor coolant system depressurization system according to an embodiment of the present invention and a nuclear power plant having the nuclear reactor coolant system. FIG. 1B shows a state in which the pressurizing portion safety valve 172 shown in FIG. Fig. 1C is a conceptual diagram showing the opening early stage of the safety reducing valve 176 shown in Fig. 1A, and Fig. 1D is a conceptual diagram showing the second half opening of the safety reducing valve 176 shown in Fig. 1A.

Referring to FIGS. 1A to 1D, the reactor coolant system 11 is a system for transporting heat energy generated by nuclear fission of nuclear fuel in the core 11a. The core 11a is installed inside the reactor coolant system 11 and the chamber 12 is installed outside the reactor coolant system 11. [

Various piping for operating the nuclear power plant 10 are connected to the reactor coolant system 11 and isolation valves are installed in the piping. The piping necessary for the normal operation of the nuclear power plant 10 is opened, Is closed by a related signal when an accident occurs.

The compartment 12 surrounds the reactor coolant system 11 to prevent leakage of radioactive material during an accident. The compartment 12 is the last means for preventing the radioactive material from leaking to the external environment. The compartment 12 is collectively referred to as a containment building, a reactor building, a containment vessel, and a safety protection vessel, and may be formed of any one of a containment building, a nuclear reactor building, a containment vessel, and a safety protection vessel.

Here, the containment vessel is a large vessel designed as a low-pressure vessel like a containment building, and the safety vessel is a small vessel designed to be small in size by increasing the design pressure. In the present invention, the containment, the reactor building, the containment vessel or the safety protection vessel are collectively referred to as a containment unit unless otherwise specified.

The residual heat eliminating system 13 removes the sensible heat of the reactor coolant system 11 and the residual heat of the core 11a. The safety injection system 14 injects the coolant into the reactor coolant system 11 to maintain the water level of the reactor coolant system 11.

The reactor coolant system decompression system may be configured to reduce the pressure inside the reactor coolant system 11 to below a certain level so as to prevent overpressure of the reactor coolant system 11 during overpressure of the nuclear power plant 10. [ . To this end, the reactor coolant system decompression system includes a pressurization unit 110 and a decompression unit 120.

The pressurizing portion 110 is made to keep the pressure of the reactor coolant system 11 constant. Specifically, the pressurizing portion 110 is configured to maintain a pressurized state exceeding the saturation pressure in order to suppress the boiling of the coolant in the core 11a, and is configured to maintain the operating pressure of the reactor coolant system 11 within a predetermined range do. The pressurizing portion 110 can be disposed inside the reactor coolant system 11 in the integral nuclear reactor as shown in FIG.

The depressurization portion 120 is formed so as to lower the pressure of the reactor coolant system 11 when the pressure of the reactor coolant system 11 rises above the reference pressure. For this, the depressurization unit 120 includes a condenser 130 and a receiver 140.

The condenser 130 receives the overpressure steam from the pressurizing unit 110 and condenses the received steam so as to prevent a coolant loss accident occurring outside the pressurizing unit 110 when the decompression unit 120 is opened . For example, the condenser 130 may be formed as a heat exchanger that condenses the steam through heat transfer between two fluids having different temperatures.

The receiving portion 140 has an internal space formed to store the condensed water condensed in the condensing portion 130 and is configured to receive the condensed water from the condensing portion by the pressure and water head, (130).

According to the structure of the present invention described above, even when the decompression unit 120 operates to decompress the reactor coolant system and the coolant flows to the outside of the pressurizing unit 110, the coolant loss accident can be basically eliminated, So that the radioactive material contained in the compartment 12 does not contaminate the environment inside the compartment 12.

Meanwhile, the reactor coolant system decompression system may further include an injection pipe 150.

The injection piping 150 is connected between the accommodating portion 140 and the reactor coolant system 11 and circulates the condensed water condensed in the condenser 130 between the depressurizing portion 120 and the reactor coolant system 11, So as to remove residual heat of the coolant system (11). To this end, the injection piping 150 is formed to supply the condensed water in the receiving portion to the reactor coolant system 11 by the head difference when the pressure of the decompression portion 120 and the reactor coolant system 11 are changed to the equilibrium state.

Accordingly, the overpressure steam discharged from the reactor coolant system 11 in accordance with the operation of the decompression unit 120 is primarily condensed by the condenser 130 and converted into condensed water, and the converted condensed water is condensed by the condenser 130 140, and then supplied into the reactor coolant system 11 again by the injection piping 150, and can be continuously circulated. As a result, the decompression and residual heat removal of the reactor coolant system 11 can be effectively performed by the connected structure of the condenser 130, the accommodating portion 140, and the reactor coolant system 11.

The injection piping 150 may be connected to the flow path of the safety injection system 14 for injecting the coolant into the reactor coolant system 11 in the event of an accident. The safety injection system 14 supplies the coolant to the primary cooling system to maintain the water level of the core 11a when the primary coolant is lost in the reactor coolant system 11, 11a.

Meanwhile, the reactor coolant system decompression system may further include a cooling water storage unit 160.

The cooling water storage unit 160 is formed to store cooling water therein. At this time, the cooling water storage unit 160 is not necessarily limited to the illustrated form, and the internal space in which the cooling water is stored may be cut off from the outside, and a general storage unit internal water storage tank (IRWST) may be used have. Here, the condenser 130 is disposed so that at least a part of the water is immersed in the cooling water stored in the cooling water storage unit 160 so that the steam transferred to the condenser 130 can be condensed by the cooling water and converted into condensed water . At this time, the condenser 130 is shown as being entirely immersed in the cooling water storage 160, but the upper and lower portions of the condenser 130 may be formed to be heat-exchanged in a mixed manner of air-cooling type and water-cooling type.

The cooling water storage portion 160 is disposed inside the compartment 12 and collects the condensed condensed water by the compartment cooling system 15 which is configured to condense the vapor inside the compartment 12 to lower the pressure . Accordingly, it can be formed to replenish the evaporated and lost cooling water.

The cooling water storage unit 160 may be disposed inside the storage unit 12 and may be configured to recover a coolant that spills into the storage unit 12 by a sprinkling system (not shown).

The cooling water storage unit 160 is formed to supply the coolant stored in the reactor coolant system 11 to the residual heat removal system 13 or the safety injection system 14 for injecting the coolant into the reactor coolant system 11 at the time of an accident It is possible.

Meanwhile, the reactor coolant system decompression system may further include the decompression pipe 170.

The decompression pipe 170 may be formed to be connected to at least one of the pressurizing unit 10 and the condensing unit 130 so as to transfer the steam generated outside the pressurizing unit 110 to the condensing unit 130. For example, the reduced pressure pipe 170 may include a first reduced pressure pipe 171 and a second reduced pressure pipe 175, as shown in FIG. 1A.

The first pressure reducing pipe 171 may be connected to the pressurizing unit 110 and the upper portion of the condensing unit 130 so as to transmit the overpressure steam generated outside the pressurizing unit 110 to the condensing unit when the pressure reducing unit 120 is opened. have.

The second pressure reducing pipe 175 may be branched from the first pressure reducing pipe 171 and connected to the pressure applying unit 110. At this time, the first decompression pipe 171 or the second decompression pipe 175 may be formed in two or more.

The first pressure reducing pipe 171 and the second pressure reducing pipe 175 may each include a pressurizing portion safety valve 172 and a safety reducing valve 176. [

The pressure relief valve 172 is provided in the first pressure reducing pipe 171 and is opened when the pressure of the reactor coolant system 11 rises above the reference pressure and the pressure of the reactor coolant system 11 is lower than the reference pressure Lt; RTI ID = 0.0 > and / or < / RTI > For example, the pressure relief valve 172 can be operated to open or close by the elastic force of the spring and the pressure difference of the reactor coolant system 11.

The safety reducing valve 176 may be provided in the second pressure reducing pipe 175 and selectively open or close the passage depending on whether the pressure of the reactor coolant system 11 rises above the reference pressure. For example, the safety pressure reducing valve 176 may be operated to open or close with electric power as a driving force according to an operation signal of a driver.

Hereinafter, the operation of the reactor coolant system decompression system in the event of a nuclear accident will be described.

First, referring to FIG. 1B, when the pressure of the reactor coolant system 11 rises above the reference pressure at the time of an accident, the pressurizing portion safety valve 172 is actuated to pressurize the pressurized steam Is discharged to the condenser (130). The steam discharged to the condenser 130 is condensed by the heat exchange in the condenser 130 and the cooling water storage 160 and the condensed condensed water is condensed in the condenser 130 And gradually increases the water level of the accommodating portion 140. [0064]

At this time, the heat transferred to the condenser 130 is transferred to the cooling water stored in the cooling water storage 160 through the natural circulation flow of the condenser 130, and the heat of the cooling water stored in the cooling water storage 160 The temperature gradually rises.

When the pressure falls below a predetermined pressure, the pressurizing portion safety valve 172 is closed to block the vapor from the pressurizing portion 110. At this time, the process described above is repeated according to the rise and fall of the pressure of the reactor coolant system (11).

At this time, the condensed water condensed in the compartment cooling system 15, the coolant sprayed in the compartment sprinkling system, or the vapor evaporated in the cooling water storage unit 160 is recovered to the cooling water storage unit 160.

Next, referring to FIG. 1C, when the opening and closing of the pressurizing portion safety valve 172 is repeated due to a complete loss of residual heat (such as a complete supply system loss accident or a complete system thermal elimination accident) , The operator determines that the safety reducing valve 176 is opened.

When the safety reducing valve 176 is opened, the overpressure steam from the pressurizing portion 110 is discharged to the condensing portion 130. In addition, the vapor discharged to the condenser 130 is condensed, and the condensed condensed water is returned to the receiver 140 again. As the condensed water is collected in the receiving portion 140, the water level of the receiving portion 140 gradually increases.

Next, referring to FIG. 1D, as the safety reducing valve 176 continues to be opened, the water level of the accommodating portion 140 gradually increases, and the pressure of the reactor coolant system 11 gradually decreases. When the pressure of the depressurizing portion 120 and the pressure of the reactor coolant system 11 are changed to the equilibrium state, the flow path of the injection piping 150 is opened and the condensed water recovered to the receiving portion 140 by the water head difference is supplied to the reactor coolant system 11 ). At this time, the injection pipe 150 may be provided with a check valve formed to open the flow path from the receiving portion 140 to the reactor coolant system.

According to the configuration of the reactor coolant system decompression system described above, when the pressure of the reactor coolant system 11 and the pressure reducing unit 120 are changed to the equilibrium state, the steam is condensed in the condenser 130 to be condensed water, Can be supplied to the reactor coolant system (11) and circulated to perform a residual heat eliminating function, so that the temperature and pressure of the reactor coolant system (11) can be maintained in a safe state. Further, the operation of the reactor coolant system depressurization system according to the opening of the safety pressure reducing valve 176 is continued until the safety pressure reducing valve 176 closes the flow path.

Hereinafter, a nuclear reactor coolant system depressurization system according to another embodiment of the present invention and other embodiments of nuclear power plants having the same will be described with reference to FIGS. 2 and 3. FIG.

FIG. 2 is a conceptual diagram showing a nuclear reactor coolant system depressurization system according to another embodiment of the present invention and a nuclear power plant having the nuclear reactor coolant system decompression system according to another embodiment of the present invention, FIG. Fig. 2 is a conceptual diagram showing a normal operation of a nuclear power plant.

2, the first pressure reducing pipe 271 and the second pressure reducing pipe 275 may each include a pressure portion safety valve 272 and an automatic pressure reducing valve 277. [

The pressure relief valve 272 is provided in the first pressure reducing pipe 271 and is opened when the pressure of the reactor coolant system 21 rises above the reference pressure and the pressure of the reactor coolant system 21 is lower than the reference pressure Lt; RTI ID = 0.0 > and / or < / RTI > For example, the pressurization safety valve 272 can be operated to open or close by the elastic force of the spring and the pressure difference of the reactor coolant system 21.

The automatic pressure reducing valve 277 is provided in the second pressure reducing pipe 275 and can be made open when the pressure of the reactor coolant system 21 rises above the reference pressure. For example, the automatic pressure reducing valve 277 is operated together with the operation of the related safety system as part of the safety system, and the flow path is automatically opened when the pressure reaches a predetermined set value in the event of an accident, It can be operated to open or close with electricity or the like as a driving force.

Referring to FIG. 3, the pressure reducing pipe 370 may include a safety relief valve 373.

The safety discharge valve 373 is provided in the pressure reducing pipe 370 and can be selectively opened and closed depending on whether the pressure of the reactor coolant system 31 rises above the reference pressure or not. Specifically, the safety relief valve 373 may be configured to simultaneously perform the functions of the pressure relief valve 172 and the safety relief valve 176 shown in FIG. 1A. For example, the safety relief valve 373 may be configured such that a pilot operated valve operated by a spring performs a pusher safety valve 172 function and a pilot operated valve operated by the motor is operated by a safety pressure reducing valve 176 Function.

4A to 4H, a reactor coolant system depressurization system and a nuclear power plant having the same according to still another embodiment of the present invention will be described.

4A to 4H are schematic diagrams showing a nuclear reactor coolant system depressurization system according to another embodiment of the present invention and a normal operation of a nuclear power plant having the same.

Referring to FIG. 4A, the pressure reducing pipe 470 may include a first pressure reducing pipe 471 and a plurality of second pressure reducing pipes 473 and 475.

The first pressure reducing pipe 471 may be provided with a pressurizing portion safety valve 472 and the plurality of second pressure reducing pipes 473 and 475 may be provided with first and second safety reducing valves 474 and 476, .

4B, the pressure reducing pipe 470 may include a first pressure reducing pipe 471 and a plurality of second pressure reducing pipes 473, 475 and 477. [

The first pressure relief valve 472a may be provided in the first pressure reducing pipe 471 and the second pressure relief valve 472b may be provided in the plurality of second pressure reducing pipes 473, A valve 476a and a second safety reducing valve 476b may be provided.

4C, the injection pipe 450 injects a coolant into the reactor coolant system 41 at the time of an accident, and supplies the coolant to the safety injection system 44 for maintaining the temperature and the pressure of the reactor coolant system 41 in a safe state. And may be formed to be connected directly to the reactor coolant system 41. [

4D, the reactor coolant system depressurizing system may further include an air discharge valve 480. [

The atmosphere discharge valve 480 is installed in a flow path formed between the pressurizing portion 410 and the condensing portion 430 and selectively opens and closes the flow path when the pressure rises above a predetermined pressure to open the reactor coolant system 41 And the decompression efficiency of the decompression unit 420 can be improved. The atmosphere discharge valve 480 may be installed directly in the flow path formed between the condenser 430 and the accommodating portion 440 or the accommodating portion 440.

4E, the reactor coolant system decompression system may further include a rupture plate 490. [

The rupture plate 490 is installed in a flow path formed between the pressurizing portion 410 and the condensing portion 430 and is formed to lower the pressure when the pressure rises above a predetermined pressure, And the decompression efficiency of the decompression unit 420 can be improved. The rupture plate 490 may be installed directly in the flow path formed between the condensing portion 430 and the accommodating portion 440 or the accommodating portion 440.

4F, the pressure reducing pipe 470 may include a first pressure reducing pipe 471 and a plurality of second pressure reducing pipes 473, 475, 477, 479. [

The first pressure relief valve 472a may be provided in the first pressure reducing pipe 471 and the second pressure relief valve 472b may be provided in the second pressure reducing pipes 473, 475, 477, 479, A valve 476a, a second safety pressure reducing valve 476b, and a third safety pressure reducing valve 476c. One end of the second pressure reducing pipe 479 in which the third safety reducing valve 476c is installed may be formed to communicate with the atmosphere inside the chamber 42.

On the other hand, referring to FIG. 4G, the reactor coolant system decompression system may further include an exhaust pipe 441 and an exhaust valve 443.

The exhaust pipe 441 is branched from the accommodating portion 440 and connected to the inside of the reactor coolant system 41.

The exhaust valve 443 opens the flow path so that the non-condensable gas accommodated in the accommodating portion 440 flows into the reactor coolant system 41. In addition, the exhaust valve 443 may be configured to block the flow of the fluid inside the reactor coolant system 41 into the receiving portion 440.

Referring to FIG. 4H, the nuclear reactor coolant system decompression system may further include a coolant storage unit 460.

The cooling water storage portion 460 is formed to store the cooling water therein.

The cooling water storage portion 460 is disposed outside the compartment portion 42 and is connected to the upper and lower portions of the condensation portion 430 and is connected between the condensation portion 430 and the cooling water storage portion 460 The cooling water stored in the cooling water storage part 460 may be moved to the condensing part 430 to condense the steam flowing into the condensing part 430. [

Hereinafter, embodiments of the construction of the condensing portion of the present invention will be described with reference to Figs. 5 to 7. Fig.

FIG. 5 is a conceptual diagram showing an example in which the condenser shown in FIG. 1A is formed by a plurality of heat exchangers, FIGS. 6A to 6C are conceptual diagrams showing examples in which the condenser shown in FIG. 7 is a conceptual view illustrating an example of a flow path formed between the condensing portion and the pressurizing portion shown in FIG. 1A.

5 and 6A, the condenser (see FIG. 1A) may be an aggregate formed by two or more heat exchangers 530a coupled to each other. Here, the condenser may be formed of a plate heat exchanger 630a having a plurality of flow channel channels as shown in FIG. 6A.

6B, the plate-type heat exchanger 630a includes a flow path resistance portion (not shown) formed to generate resistance to the flow of cooling water so as to stabilize the flow of the cooling water stored in the cooling water storage portion 633).

Referring to FIG. 6C, the plate-type heat exchanger 630a includes a plate type heat exchanger 630a in which a channel of the cooling water is entirely opened to facilitate the flow of cooling water stored in the cooling water storage portion (see FIG. 1A) 630a may be formed to have a flow path opened to the entire part thereof.

7, the plate-type heat exchanger 730a includes an inlet solenoid 733 and an outlet solenoid 735, which are introduced in a steam state from the pressurizing portion (see FIG. 1A) and discharged as condensed water, respectively , The flow path of the fluid flowing from the pressurizing portion may be formed to be isolated from the flow path of the cooling water stored in the cooling water storage portion (see FIG. 1A).

However, the scope of the present invention is not limited to the configuration and method of the embodiments described above, and all or some of the embodiments may be selectively combined so that various modifications may be made to the embodiments. In addition, the present invention can be applied to all equivalents of inventions, such as inventions that can be modified, added, deleted, or replaced at the level of those skilled in the art, It belongs to the scope is self-evident.

110: pressure applying unit 120:
130: condenser part 140: accommodating part
150: injection piping 160: cooling water storage part
170: Pressure reducing piping

Claims (21)

A pressurizing portion for keeping the pressure of the reactor coolant system constant; And
And a decompression unit configured to lower the pressure of the reactor coolant system when the pressure of the reactor coolant system rises above a reference pressure,
The pressure-
A condenser for receiving steam from the pressure unit to condense the steam to prevent a loss of coolant generated outside the pressure unit when the decompression unit is opened; And
And a receiving portion disposed at a lower portion of the condenser to receive the condensed water by a head and a pressure difference, the condenser having an internal space for storing condensed water condensed in the condenser,
The reactor coolant system decompression system comprises:
Further comprising at least one decompression pipe connected to the pressurizing unit and the condensing unit, respectively, to transmit steam generated outside the pressurizing unit to the condensing unit when the decompression unit is opened. The method according to claim 1,
Further comprising an inlet pipe connected between the receiving portion and the reactor coolant system,
The injection piping may further include a pressure reducing unit and a reactor coolant system for circulating the condensed water between the decompression unit and the reactor coolant system to remove residual heat of the reactor coolant system, Wherein the reactor coolant system is configured to supply condensate in the receiver to the reactor coolant system. 3. The method of claim 2,
Wherein the injection piping is formed to be connected to a safety injection system for injecting a coolant into the reactor coolant system in the event of an accident. 3. The method of claim 2,
Wherein the injection piping is formed to extend from a lower portion of the accommodating portion to be connected to the reactor coolant system. The method according to claim 1,
Further comprising a cooling water storage portion formed to store cooling water therein,
Wherein the condenser is arranged so as to be immersed in the cooling water stored in the cooling water storage part so that the steam transferred to the condensing part can be condensed by the cooling water. 6. The method of claim 5,
Wherein the cooling water reservoir is disposed inside the compartment and is adapted to collect condensed water condensed by a compartment cooling system that reduces the pressure by condensing the vapor inside the compartment. 6. The method of claim 5,
Wherein the cooling water storage unit is disposed inside the compartment and is adapted to recover a coolant that is spilled into the compartment by the compartment water sprinkling system in the event of an accident. 6. The method of claim 5,
Wherein the cooling water reservoir is formed to supply a coolant to a safety injection system for injecting a coolant into the reactor coolant system in the event of an accident. The method according to claim 1,
Further comprising a cooling water storage portion formed to store cooling water therein,
The cooling water storage portion is disposed outside the compartment and is connected to the upper and lower portions of the condensing portion. The cooling water stored in the cooling water storage portion is condensed by the condensation portion and the cooling water storage portion, Wherein the reactor coolant system decompression system comprises: delete The method according to claim 1,
Wherein the decompression piping includes at least one safety discharge valve installed to selectively open and close the passage according to whether the pressure of the reactor coolant system rises above a reference pressure. The method according to claim 1,
The pressure-
A first pressure reducing pipe connected to the pressurizing unit and the upper portion of the condensing unit to transfer steam generated outside the pressurizing unit to the condensing unit when the pressure reducing unit is opened; And
And at least one second pressure reducing pipe branched from the first pressure reducing pipe and connected to the pressurizing portion. 13. The method of claim 12,
The first pressure reducing pipe is opened when the pressure of the reactor coolant system rises above a reference pressure and is at least one pressure relief valve closed when the pressure of the reactor coolant system falls below a reference pressure and,
Wherein the second pressure reducing pipe comprises at least one safety reducing valve selectively installed to open and close the flow path depending on whether the pressure of the reactor coolant system rises above a reference pressure. 13. The method of claim 12,
The first pressure reducing pipe is opened when the pressure of the reactor coolant system rises above a reference pressure and is at least one pressure relief valve closed when the pressure of the reactor coolant system falls below a reference pressure and,
Wherein the second decompression piping comprises at least one automatic decompression valve installed to open when the pressure of the reactor coolant system rises above a reference pressure. The method according to claim 1,
At least one of the flow path formed between the pressurizing portion and the condensing portion, the flow path formed between the condensing portion and the accommodating portion, or the accommodating portion is provided to lower the pressure when the pressure rises above a preset pressure A reactor coolant system depressurization system further comprising a rupture plate. The method according to claim 1,
At least one of the flow path formed between the pressurizing portion and the condensing portion, the flow path formed between the condensing portion and the accommodating portion, or the accommodating portion is provided so as to selectively open and close the flow path when the pressure rises above a predetermined pressure A reactor coolant system depressurization system further comprising an atmospheric release valve. 10. The method according to claim 5 or 9,
Wherein the condenser is formed of at least one plate heat exchanger having a plurality of flow channel channels. 18. The method of claim 17,
Wherein the plate type heat exchanger includes a flow path resistance portion for generating a resistance to the flow of the cooling water so as to stabilize the flow of the cooling water stored in the cooling water storage portion. 18. The method of claim 17,
Wherein the plate-type heat exchanger is formed in such a manner that the flow path of the cooling water is entirely opened so as to smoothly flow the cooling water stored in the cooling water storage part. The method according to claim 1,
An exhaust pipe branched from the accommodating portion and connected to the inside of the reactor coolant system; And
Further comprising an exhaust valve that opens the flow path so that non-condensable gas contained in the accommodating portion flows into the reactor coolant system. Reactor coolant system;
A compartment for enclosing said reactor coolant system to prevent leakage of radioactive material during an accident; And
And a reactor coolant system decompression system configured to suppress an increase in the pressure inside the reactor by cooling water or steam emitted from the reactor or the secondary system at the time of an accident,
The reactor coolant system decompression system comprises:
A pressurizing portion for keeping the pressure of the reactor coolant system constant; And
And a decompression unit configured to lower the pressure of the reactor coolant system when the pressure of the reactor coolant system rises above a reference pressure,
The pressure-
A condenser for receiving steam from the pressure unit to condense the steam to prevent a loss of coolant generated outside the pressure unit when the decompression unit is opened; And
And an accommodating portion having an inner space for storing condensed water condensed in the condensing portion and disposed at a lower portion of the condensing portion to receive the condensed water by a head and pressure difference,
The reactor coolant system decompression system comprises:
Further comprising at least one decompression pipe connected to the pressurizing unit and the condensing unit, respectively, so as to transfer steam generated outside the pressurizing unit to the condensing unit when the decompression unit is opened.

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