KR101658476B1 - Reactor coolant system depressurization system and nuclear power plant having the same - Google Patents

Abstract

Disclosed are a reactor coolant system depressurization system and a nuclear power plant having the same. The reactor coolant system depressurization system comprises: a pressurizer which maintains a pressurized state of a reactor coolant system; a condensation heat exchanger which is a driven residual heat removal system which removes heat from the reactor coolant system and residual heat of a reactor core by heat exchange between types of fluid; and depressurization facilities formed to prevent overpressure of the reactor coolant system by using the condensation heat exchanger during an operation failure of the driven residual heat removal system. The depressurization facilities comprise: a depressurization pipe which is connected to the pressurizer and the condensation heat exchanger to provide vapor, discharged by the pressurizer, to the condensation heat exchanger; and an injection pipe which is connected to the condensation heat exchanger and the reactor coolant system to inject condensed water, generated by the condensation heat exchanger, into the reactor coolant system. The present invention is to provide the reactor coolant system depressurization system for preventing an increase of pressure in the reactor coolant system.

Description

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

The present invention relates to a decompression system for suppressing overpressure of a reactor coolant system and a nuclear power plant having the same.

1. Types of reactors

Reactors can be distinguished by the location of the main equipment and the way the safety system is implemented.

(1) First, reactors are divided into separate reactors and integral reactors depending on the installation location of main equipment. Major equipment refers to steam generators, pressurizers, and pumps. The main equipment of the separable reactor is installed outside the reactor vessel. Korea's commercial reactor is an example of a separate reactor. The main instrument of the integral reactor is installed inside the reactor vessel. Korea's SMART reactor (System-integrated Modular Advanced ReacTor) is an example of an integrated reactor.

(2) Next, the reactor is divided into an active reactor and a passive reactor depending on the implementation of the safety system. Active devices are used in the safety system of active reactors. An active device refers to a device that operates by the power supplied from an emergency generator or the like. For example, a pump is an example of an active device. The safety system of a passive nuclear reactor refers to a device that is operated by force. The driving force includes, for example, gravity or gas pressure.

The passive reactor includes a passive safety system. The passive safety system ensures safe operation of the reactor with only the natural forces built into the system without any operator action or safety class AC (AC) power source (eg emergency diesel generator) for the time required for regulatory requirements (more than 72 hours) , And after 72 hours, it is a system that can be assisted by the driver's action or non-safety system.

2. Passive residual heat removal system

(1) The passive safety system includes a passive residual heat removal system (auxiliary water supply system or residual heat removal system of general nuclear power plants). In the nuclear industry, passive residual heat removal systems are employed in a variety of nuclear power plants, including integrated reactors. The passive residual heat removal system removes the heat of the reactor coolant system (the sensible heat of the reactor coolant system and the residual heat of the core) in the event of an accident at the nuclear power plant. BACKGROUND ART [0002] The related art related to the passive residual heat removal system is described in the prior patent documents below.

1) Patent Registration No. 10-0261752 (July 15, 2000)

2) Patent Registration No. 10-0419194 (Feb. 19, 2004)

3) Patent Registration No. 10-1234570 (Feb.

(2) The passive residual heat removal system can be classified according to the cooling water circulation system and the heat exchanger cooling system.

First, the circulation method of cooling water includes: 1) a method of cooling the reactor by directly circulating the primary cooling water of the reactor (AP1000: Westinghouse, USA) and 2) a method of cooling the reactor by circulating the secondary cooling water by using the steam generator SMART reactor: Domestic) are mainly used. 3) A method of directly condensing the primary cooling water into the tank (CAREM: Argentina) is used in some cases.

Next, the cooling system for the opposite side of the heat exchanger (condensation heat exchanger) in the passive residual heat removal system is 1) water-cooled (AP1000) applied in most reactors, 2) some air- cooled, WWER 1000: Russia), and 3) water-cooled air-combined type (IMR: Japan). The heat exchanger of the passive residual heat removal system performs the function of transferring the heat received from the reactor to the emergency cooling tank or the like. The heat is discharged to the outside through the emergency cooling tank or the like due to the final heat sink. In the heat exchanger system, a condensation heat exchanger which exhibits excellent heat transfer efficiency by using vapor condensation phenomenon is widely used

3. Reactor Coolant System Reducing Equipment

If the pressure in the reactor coolant system rises abnormally, the reactor coolant system can be damaged by overpressure. The reactor coolant system depressurization system protects the reactor coolant system by suppressing pressure build up in the reactor coolant system.

Conventional reactor coolant system depressurization facilities were configured to discharge steam to 1) reactor drainage tank, 2) containment tank, or 3) to the atmosphere inside the containment building. Accordingly, the conventional reactor coolant system depressurization equipment has a problem that it develops as a coolant loss accident if it is continuously operated. The loss of a coolant is a radioactive material contained in the coolant, which pollutes most of the equipment exposed to the environment inside the containment building, resulting in a great deal of difficulty in following up after the accident. Therefore, it is desirable that the loss of a non-coolant is extended to a coolant loss accident as far as possible in terms of ensuring the safety of the nuclear power plant and securing ease of follow-up measures.

It is an object of the present invention to provide a reactor coolant system depressurization system for suppressing a pressure rise in a reactor coolant system. In particular, the present invention is to provide a nuclear reactor coolant system depressurization system that simplifies the configuration and a nuclear power plant having the same.

Conventional techniques for suppressing the pressure rise of the reactor coolant system may cause a loss of coolant. The present invention proposes a nuclear reactor coolant-based decompression system capable of preventing an overpressure accident of a reactor coolant system from expanding into a coolant loss accident even if the reactor coolant system is continuously operated to suppress a pressure rise, and a nuclear reactor equipped with the same .

To achieve the above object, according to one aspect of the present invention, there is provided a nuclear reactor coolant system depressurization system comprising: a pressurizer for maintaining a pressurized state of a reactor coolant system; A condensation heat exchanger for removing the sensible heat of the reactor coolant system and the residual heat of the core through heat exchange between fluids; And a decompression facility for preventing an overpressure of the reactor coolant system using the condensation heat exchanger when a design standard excess accident in which the function of the passive residual heat elimination system is lost occurs, A pressure reducing pipe connected to the pressurizer and the condensation heat exchanger to supply steam to the condensation heat exchanger; And an injection pipe connected to the condensation heat exchanger and the reactor coolant system to inject the condensed water formed in the condensation heat exchanger into the reactor coolant system.

According to an example of the present invention, the depressurization facility includes a pressurizer safety pipe connected to the pressurizer and the reactor drainage tank; And a pressurizer safety valve installed in the pressurizer safety pipe, the pressurizer safety valve being opened and closed based on a preset pressure to suppress an abrupt pressure rise of the reactor coolant system.

According to another embodiment of the present invention, the pressure reducing apparatus includes a pressure reducing valve installed in the pressure reducing pipe or the injection pipe, and when a design standard excess accident in which the function of the driven residual heat eliminating system is lost occurs, The valve can be opened to lower the pressure of the reactor coolant system.

At least a partial region of the decompression pipe or at least a partial region of the injection pipe may be composed of a plurality of branches, and the at least one pressure reducing valve may be provided for each of the plurality of branches.

According to another embodiment of the present invention, the depressurization facility includes a pilot-operated safe discharge valve installed in the depressurization pipe, and the pilot-operated safety relief valve is provided for suppressing an abrupt pressure rise of the reactor coolant system A first valve comprising: And a second valve operated to lower the pressure of the reactor coolant system when the function of the driven residual heat elimination system is lost due to occurrence of an accident exceeding the design standard.

At least a partial region of the pressure reducing pipe is composed of a plurality of branches, and the pilot drive safe discharge valve may be provided for each of the plurality of branches.

The condensing water accommodating unit may include a condensing water reservoir for storing the condensed water discharged from the condensing heat exchanger, and the condensing water reservoir for condensing the condensed water stored in the condensing water reservoir to the reactor coolant system .

The decompression facility may further include a rupture plate installed at least one of the decompression pipe, the injection pipe, and the condensed water storage unit. The rupture plate may be ruptured when the pressure of the decompression facility rises above a preset reference.

The decompression facility further includes an air release isolation valve disposed at least one of the decompression pipe, the injection pipe, and the condensed water storage unit. When the pressure of the decompression facility rises above a predetermined reference value Can be opened.

The non-condensable gas exhaust pipe is connected to a lower portion of the condensation heat exchanger, an upper portion of the condensed water accommodating portion, or the injection pipe. The non-condensable gas exhaust pipe includes a non-condensable gas exhaust pipe configured to remove non-condensable gas flowing through the injection pipe. .

According to another embodiment of the present invention, the driven residual heat elimination system includes an emergency cooling water storage part formed to store cooling water, and the emergency cooling water storage part has an opening for discharging steam formed by evaporation of the cooling water .

The emergency cooling water storage part is installed outside the compartment, the condensing heat exchanger is installed inside the compartment, and the emergency cooling water storage part and the condensation heat exchanger are connected to the first and second circulation pipes for circulation of the cooling water Respectively.

The emergency cooling water storage part may be provided outside the compartment, and the condensation heat exchanger may be installed inside the emergency cooling water storage part.

The emergency cooling water storage part may be installed inside the storage part, and the condensation heat exchanger may be installed inside the emergency cooling water storage part.

According to another example of the present invention, the passive residual heat eliminating system is connected to the reactor coolant system to circulate a primary fluid, and the pressure reducing piping is connected to the passive residual heat eliminating system for operation of the driven residual heat eliminating system and operation of the pressure reducing equipment The passive residual heat eliminating system may include a water supply pipe connected to the condensing heat exchanger and the reactor coolant system bypassing the injection pipe.

The passive residual heat elimination system includes an isolation valve installed in the water supply pipe, and the isolation valve is opened during operation of the driven residual heat removal system and may be closed during operation of the pressure reduction facility.

According to another embodiment of the present invention, the driven residual heat elimination system is connected to a steam generator installed at the boundary between the primary system and the secondary system so as to circulate the secondary fluid, and the driven residual heat elimination system includes: A steam pipe branched from the main steam turbine connected to the generator and the turbine system and connected to the condensation heat exchanger; And a water supply pipe branched from the main water supply pipe connected to the steam generator and the water supply system and connected to the condensation heat exchanger.

The passive residual heat removal system includes isolation pipes installed in the steam pipe and the water supply pipe, and the isolation valves are opened when the passive residual heat removal system is operated and closed when the decompression facility is operated.

According to another embodiment of the present invention, the depressurization facility includes an automatic depressurization piping branching from the depressurization piping and connected to the reactor building internal recharging tank; And an automatic pressure reducing valve installed in the automatic pressure reducing pipe and opened when the pressure of the reactor coolant system reaches a predetermined operating value.

Further, in order to realize the above-mentioned problem, the present invention discloses a nuclear power plant having a nuclear reactor coolant system depressurization system. Nuclear reactors, reactor coolant system; A compartment formed to enclose the reactor coolant system; And a reactor coolant system depressurization system for preventing overpressure of the reactor coolant system, wherein the reactor coolant system depressurization system comprises: a pressurizer that maintains a pressurized state of the reactor coolant system; A condensation heat exchanger for removing the sensible heat of the reactor coolant system and the residual heat of the core through heat exchange between fluids; And a depressurization facility for preventing overpressure of the reactor coolant system by using the condensation heat exchanger when the passive residual heat elimination system can not operate, wherein the depressurization facility is provided with a condenser for cooling the steam discharged from the reactor coolant system to the condensation heat exchanger A decompression pipe connected to the reactor coolant system and the condensation heat exchanger to supply the reactant coolant; And an injection pipe connected to the condensation heat exchanger and the reactor coolant system to inject the condensed water formed in the condensation heat exchanger into the reactor coolant system.

According to an example of the present invention, the nuclear power plant includes a safety injection system configured to inject a coolant into the reactor coolant system, and the safety injection system includes a safety injection system connected to the reactor coolant system to form an injection path of the coolant, And the injection piping may be connected to the safety injection piping.

According to the present invention having the above-described structure, since the decompression facility shares the condensation heat exchanger of the driven residual heat elimination system, the configuration of the reactor coolant system decompression system can be simplified. The simplicity of the reactor coolant system means that the probability of nuclear accidents is low and the safety of nuclear power plants is improved.

In the present invention, the steam discharged from the reactor coolant system is condensed in the condensation heat exchanger of the passive residual heat removal system, and the condensed water formed by the condensation of the steam in the condensation heat exchanger is supplied again to the reactor coolant system. Therefore, the decompression system of the reactor coolant system of the present invention can prevent the overpressure accident of the reactor coolant system from spreading to the coolant loss accident even if it operates continuously.

1 is a conceptual diagram showing a normal operation state of a nuclear reactor coolant system depressurization system and a nuclear power plant having the same according to a first embodiment of the present invention;
FIG. 2 is a conceptual view showing the operation state of a passive residual heat removal system or a reactor coolant system decompression system in the event of a virtual accident in the nuclear power plant shown in FIG. 1;
3 is a conceptual diagram showing a normal operation state of a nuclear reactor coolant system depressurization system and a nuclear power plant having the same according to a second embodiment of the present invention.
FIG. 4 is a conceptual view showing the operation state of a passive residual heat removal system or a reactor coolant system decompression system in the event of a virtual accident in the nuclear power plant shown in FIG.
FIG. 5 is a conceptual view showing a normal operation state of a nuclear reactor coolant system depressurization system and a nuclear power plant having the same according to a third embodiment of the present invention. FIG.
FIG. 6 is a conceptual diagram showing the operating state of a passive residual heat eliminating system or a reactor coolant system decompression system in the event of a virtual accident in the nuclear power plant shown in FIG. 5;
FIG. 7 is a conceptual diagram showing a nuclear reactor coolant system depressurization system according to a fourth embodiment of the present invention and a normal operation state of a nuclear power plant having the same. FIG.
FIG. 8 is a conceptual view showing the operation state of a passive residual heat removal system or a reactor coolant system decompression system at the time of a virtual accident in the nuclear power plant shown in FIG.
9 is a conceptual diagram showing a normal operation state of a nuclear reactor coolant system depressurization system and a nuclear power plant having the same according to a fifth embodiment of the present invention.
FIG. 10 is a conceptual view showing the operation state of a passive residual heat removal system or a reactor coolant system decompression system at the time of a virtual accident in the nuclear power plant shown in FIG.
FIG. 11 is a conceptual diagram showing a nuclear reactor coolant system depressurization system according to a sixth embodiment of the present invention and a normal operation state of a nuclear power plant having the same.
FIG. 12 is a conceptual view showing the operation state of a passive residual heat eliminating system or a reactor coolant system decompression system in a nuclear accident shown in FIG. 11; FIG.
FIG. 13 is a conceptual view showing a normal operation state of a nuclear reactor coolant system depressurization system and a nuclear power plant having the same according to a seventh embodiment of the present invention. FIG.
FIG. 14 is a conceptual view showing the operation state of a passive residual heat removal system or a reactor coolant system decompression system at the time of a virtual accident in the nuclear power plant shown in FIG.
15 is a conceptual view showing a normal operation state of a nuclear reactor coolant system depressurization system and a nuclear power plant having the same according to an eighth embodiment of the present invention.
FIG. 16 is a conceptual view showing the operating state of a passive residual heat removal system or a reactor coolant system decompression system at the time of a virtual accident in the nuclear power plant shown in FIG. 15;
17 is a schematic diagram showing a nuclear reactor coolant system depressurization system according to a ninth embodiment of the present invention and a normal operation state of a nuclear power plant having the same.
18 is a conceptual view showing the operation state of a passive residual heat removal system or a reactor coolant system decompression system in the event of a virtual accident in the nuclear power plant shown in FIG.
FIG. 19 is a conceptual diagram showing a normal operation state of a nuclear reactor coolant system depressurization system and a nuclear power plant having the same according to a tenth embodiment of the present invention; FIG.
20 is a conceptual view showing the operation state of a passive residual heat removal system or a reactor coolant system decompression system at the time of a virtual accident in the nuclear power plant shown in FIG.

Hereinafter, a nuclear reactor coolant system depressurization system and a nuclear power plant having the nuclear reactor coolant system according to the present invention will be described in detail with reference to the drawings. In the present specification, the same reference numerals are given to the same components in different embodiments, and the description thereof is replaced with the first explanation. As used herein, the singular forms "a", "an" and "the" include plural referents unless the context clearly dictates otherwise.

1, 3, 5, 7, 9, 11, 13, 15, 17, and 19 show the normal operation states of the nuclear power plants in each of the embodiments. Figures 2, 4, 6, 8, 10, 12, 14, 16, 18 and 20 illustrate the occurrence of a virtual accident in each of the embodiments. In the drawings, the left and right sides are shown differently for convenience of explanation. It should be noted, however, that this is merely for convenience of explanation, and the left and right sides of the drawings do not represent different nuclear power plants.

In addition, depending on the characteristics of the safety equipment of the nuclear power plant, the number of series of the passive residual heat removal system and the decompression system may not be the same. For example, if the passive residual heat removal system is composed of 4 series and the decompression system is composed of 2 series, the passive residual heat removal system 2 series may not have a decompression system.

1 is a conceptual view showing a normal operation state of a nuclear reactor coolant system depressurization system 1000 and a nuclear power plant 100 having the same according to the first embodiment of the present invention.

The nuclear power plant 100 includes a reactor coolant system 101 (or a reactor 101 of an integral nuclear reactor), a core 101a, a reactor coolant pump 101b, a steam generator 102, a storage unit 103, a water supply system 104, (105) and a compartment cooling system (or equivalent dispensing cooling system, 106). In addition to the components shown in FIG. 1, the nuclear power plant 100 may include systems for normal operation of the other nuclear power plants 100 and various systems for securing the safety of the nuclear power plant 100.

The reactor coolant system 101 (RCS) is installed inside the compartment 103. The reactor coolant system 101 is a system for transferring and transporting thermal energy generated by nuclear fission of fuel in the core 101a. The inside of the reactor coolant system 101 is filled with a coolant (primary fluid). In the event of an accident such as a loss of coolant, steam may be discharged from the reactor coolant system 101, and the storage part 103 may block leakage of the radioactive material contained in the steam to the outside.

Core 101a (Reactor Core) refers to a region within the reactor where a chain reaction can take place. Nuclear fuel exists in the core 101a, and nuclear fission occurs actively in the core 101a. Generally, the core 101a is composed of a fuel and a moderator. In a pressurized water reactor, the coolant passes between the nuclear fuel in a liquid state and acts as a moderator while cooling the nuclear fuel.

Reactor coolant pump 101b (RCP) is arranged to facilitate the circulation of the coolant, which is the primary fluid. The reactor coolant pump 101b assists in the flow of the coolant entering the core 101a. As shown in FIG. 1, the reactor coolant pump 101b may be installed in a horizontal direction. However, the installation position and installation direction of the reactor coolant pump 101b are not limited thereto.

The steam generator 102 is installed at the boundary between the primary system and the secondary system. The primary system produces nuclear energy and delivers the produced energy to the steam generator 102. The reactor coolant system 101, the core 101a, the reactor coolant pump 101b, the pressurizer 1010, and the like correspond to the primary system. The primary fluid refers to the fluid (coolant) circulating through the primary system. The secondary system supplies water to the steam generator (102) and produces electricity using the steam produced in the steam generator (102). The water supply system 104, the turbine system 105, and the like correspond to the secondary system. The secondary fluid refers to the fluid (water, steam) circulating in the secondary system. The primary fluid and the secondary fluid are thoroughly isolated from each other.

The steam generator 102 supplies the high-temperature and high-pressure coolant heated by the core 101a to heat the feed water. In the steam generator 102, heat exchange is performed between the coolant and the water, and the water is heated to become steam. The water supply system 104 supplies water to the steam generator 102 through the main water supply pipe 104a when the power plant 100 is operated normally. The steam generated in the steam generator 102 is supplied to the turbine system 105 through the main engine 105a and used for power generation in the turbine system 105. [

The steam generator 102 operates not only when the nuclear reactor 100 is in the settling operation but also when an accident such as a coolant loss accident occurs. At least a portion of the safety systems such as the passive residual heat removal system 1020 are connected to the main water supply pipe 104a and the main steam pipe 105a and are configured to remove the heat of the reactor coolant system 101 using the steam generator 102 .

The compartment 103 is formed to enclose the reactor coolant system 101. The compartment 103 serves as a final barrier to prevent leakage of the radioactive material from the nuclear power plant 100 to the external environment. The compartment 103 can be distinguished according to the material constituting the pressure boundary. The containment building (or reactor building) consists of reinforced concrete. The containment vessel and safety protection vessel consist of steel vessel. A containment vessel is a large vessel designed to be a low-pressure vessel like a containment building. A safety protective container is a compact container that is designed to be small by increasing the design pressure. Unless otherwise stated, in this specification, the compartment 103 is used to include both containment buildings, reactor buildings, containment vessels, and safety protection containers.

The compartment cooling system or the PCCS (Passive Containment Cooling System) 106 is configured to maintain the integrity of the compartment 103 when an accident occurs in which the pressure of the compartment 103 rises. The compartment cooling system cools and condenses the vapor inside the compartment 103 to suppress the pressure rise of the compartment 103. [

Nuclear power plant 100 includes a reactor coolant system depressurization system 1000.

The reactor coolant system depressurization system 1000 suppresses the pressure rise of the reactor coolant system 101 when an accident occurs in which the pressure of the reactor coolant system 101 is suddenly increased. The reactor coolant system depressurization system 1000 includes a pressurizer 1010, a condensation heat exchanger 1021, and a depressurization facility 1030.

The pressurizer 1010 functions to maintain the pressurized state exceeding the saturated pressure of the cooling water so as to suppress the boiling of the coolant in the pressurized water reactor. The pressurizer 1010 may be applied in any form as well as a steam or nitrogen gas type, and is not limited to a particular type of pressurizer 1010. The pressurizer 1010 may be installed in the upper space of the reactor coolant system 101.

The passive residual heat removal system 1020 removes the sensible heat of the reactor coolant system 101 and the residual heat of the core 101a through heat exchange between fluids in the condensation heat exchanger 1021. [ The depressurization facility 1030 of the depressurization system 1000 of the reactor coolant system of the present invention is configured to operate in conjunction with the condensation heat exchanger 1021 of the driven residual heat elimination system 1020. Since the depressurization facility 1030 is configured to operate in a limited manner for a design basis excess accident (design basis excess accident where all of the driven residual heat removal system 1020 does not operate), the driven residual heat removal system 1020 and the condensation heat exchanger 1021, Can be used jointly.

First, referring to the left part of FIG. 1, a driven residual heat elimination system 1020 that operates normally at the time of an accident will be described. Next, referring to the right side of FIG. 1, a depressurization facility 1030 that operates in conjunction with the condensation heat exchanger 1021 in an overpressure accident where the passive residual heat elimination system 1020 does not operate normally will be described. The left and right sides of FIG. 1 are distinguished based on the vertical dotted line of the reactor coolant system 101. The dotted line separating left and right is for the convenience of explanation only and is not intended to distinguish left and right sides from each other.

On the left side of the dotted line, the driven residual heat removal system 1020 and the pressurizer safety valve 1035 are shown. For ease of understanding, the left drift residual heat removal system 1020 is shown to be distinct from the reactor coolant system 101 pressurization system. And the reactor coolant system decompression system 1000 using the condensation heat exchanger 1021 of the driven residual heat elimination system 1020 is shown on the right side of the dotted line.

The driven residual heat elimination system 1020 shown in FIG. 1 is configured to circulate the secondary fluid using the steam generator 102. The driven residual heat removal system 1020 includes a condensation heat exchanger 1021, a steam pipe 1022, a water supply pipe 1023, an emergency cooling water storage unit 1025, circulation pipes 1026 and 1027, (1022a, 1023a, 1023b, 1026a, 1026b, 1027a).

The condensation heat exchanger 1021 is a place where heat exchange is performed between fluids. The fluid to be heat-exchanged in the condensation heat exchanger 1021 may vary depending on the operating state of the nuclear power plant 100. The operating state of the nuclear power plant 100 can be divided into (1) a case where the driven residual heat elimination system 1020 operates, and (2) a case where the reduced-pressure facility 1030 operates. (1) When the driven residual heat elimination system 1020 is operated, 1) the fluid circulating the steam generator 102 and the cooling water of the emergency cooling water reservoir 1025 heat-exchange with each other in the condensing heat exchanger 1021. (2) When the depressurization facility 1030 is operated, the condensation heat exchanger 1021 is configured such that 1) steam emitted from the reactor coolant system 101 and 2) cooling water of the emergency cooling water storage part 1025 (in the case of air- Are exchanged with each other.

The installation position of the condensation heat exchanger 1021 may vary depending on the design of the nuclear power plant 100. The condensing heat exchanger 1021 of FIG. 1 is installed in the internal space of the compartment 103, but is not limited thereto.

A shell-and-tube heat exchanger or a plate heat exchanger may be applied to the condensation heat exchanger 1021. The condensing heat exchanger 1021 shown in Fig. 1 corresponds to a plate heat exchanger. The shell-and-tube heat exchanger will be described later with reference to Figs. 3 and 4. Fig.

The plate type heat exchanger is a concept including a plate type heat exchanger and a plate type heat exchanger.

The plate-type heat exchanger is a heat exchange structure in which welding is eliminated between the plates of the heat exchanger by using a dense flow path arrangement and diffusion bonding technique. The plate-type heat exchanger has advantages such as durability against high-temperature and high-pressure environment and excellent heat exchange performance with high degree of integration.

The plate-type heat exchanger is a heat exchange structure in which a plate is extruded to form a channel channel, and plates are joined by gasket, general welding or brazing welding. Plate heat exchangers have applications similar to those of plate-type heat exchangers, but are mainly used in low-pressure environments. The heat exchange performance of a plate heat exchanger is lower than that of a plate heat exchanger and is superior to that of a shell and tube heat exchanger. Also, the plate heat exchanger can be manufactured more easily than the plate heat exchanger.

The plate-type heat exchanger in the present invention encompasses not only a plate-type heat exchanger and a plate-type heat exchanger, but also a case where there are differences in the processing method and the joining method of the plate (plate). In the case of applying the plate heat exchanger to the condensation heat exchanger 1021, the facility can be optimized by using the high degree of integration.

A plurality of condensation heat exchangers 1021 may be gathered to form a condensation heat exchanger aggregate (not shown). Since the aggregate of the condensing heat exchanger 1021 has a smaller flow path resistance than that of one condensing heat exchanger 1021, the natural circulation of the cooling water stored in the emergency cooling water storage unit 1025 can be improved. At this time, the improvement of the natural circulation is achieved not only by the micro flow path inside the plate type heat exchanger but also by the natural convection through the side flow path between the condensation heat exchangers 1021.

The flow path of the condensation heat exchanger 1021 includes a first flow path (not shown) and a second flow path (not shown). In the first flow path, the fluid of the passive residual heat removing system 1020 and the pressure reducing equipment 1030 flows. And the cooling water of the emergency cooling water storage portion 1025 (in the case of the air-cooling type, the outside atmosphere) flows in the second flow path. In the case of the plate type heat exchanger, the first flow path and the second flow path are formed alternately for each plate. For example, the plate having the first flow path and the plate having the second flow path are alternately arranged.

The condensation heat exchanger 1021 shown in Fig. 1 has a closed flow path. The concept of a closed channel is distinguished from an open channel. The closed flow path means a flow path in which the fluid flows in and out only through the inlet and outlet formed respectively at the upper and lower portions of the condensation heat exchanger 1021. The open-type flow path means a flow path in which fluid flows in and out through outer surfaces other than the upper and lower ports. In the drawings, whether the first flow path and the second flow path are closed type or open type can be deduced from the arrows indicating inflow and outflow of the fluid.

The closed flow path and the open flow path can be determined as follows according to the installation positions of the emergency cooling water storage section 1025 and the condensation heat exchanger 1021. The following (1) to (4) are explanations that apply to all of FIGS. 1 to 20.

(1) When the emergency cooling water storage portion 1025 is provided outside the compartment portion 103 and the condensation heat exchanger 1021 is installed inside the compartment portion 103, the first flow path and the second flow path are both closed type Lt; / RTI >

(2) When the emergency cooling water storage part 1025 is installed inside the compartment part 103 and the condensation heat exchanger 1021 is installed inside the emergency cooling water storage part 1025, the first flow path is closed The second flow path is open type.

(3) When the emergency cooling water storage portion 1025 is not installed and the condensing heat exchanger 1021 is installed inside the compartment 103, the first flow path and the second flow path (the outside air flow) Lt; / RTI >

(4) When the emergency cooling water storage section 1025 is not provided and the condensing heat exchanger 1021 is provided outside the compartment 103, the first flow path is closed and the second flow path Is made open.

The steam pipe 1022 branches (or branches) from the main engine 105a and is connected to the condensation heat exchanger 1021. [ The steam generated in the steam generator 102 is discharged to the main steam pipe 105a and the steam pipe 1022 is connected to the steam generated in the steam generator 105a during operation of the driven residual heat elimination system 1020 or the reduced- To the condensation heat exchanger (1021).

The steam pipe 1022 is provided with an isolation valve 1022a. The isolation valve 1022a provided in the steam pipe 1022 may be open or closed during normal operation of the nuclear power plant 100. [ The isolation valve 1022a provided in the steam pipe 1022 is opened when the driven residual heat removal system 1020 is operated and closed when the reduced pressure facility 1030 is operated. The isolation valve 1022a prevents fluid from entering the steam line 1022 during operation of the depressurization facility 1030.

The water supply pipe 1023 is branched from the main water supply pipe 104a and connected to the condensation heat exchanger 1021. [ The water feed pipe 1023 in the operation of the driven residual heat elimination system 1020 or the reduced pressure facility 1030 forms a flow path for flowing the condensed water from the condensing heat exchanger 1021 to the main water supply pipe 104a.

The water supply pipe 1023 is provided with an isolation valve 1023a and a check valve 1023b. The isolation valve 1023a provided in the water supply pipe 1023 is closed at the time of normal operation of the nuclear reactor 100. [ The isolation valve 1023a provided in the water supply pipe 1023 is opened when the driven residual heat removal system 1020 is operated and closed when the reduced pressure facility 1030 is operated. The check valve 1023b prevents backward flow of water.

Emergency cooling water storage portion 1025 is formed to store cooling water. The installation position of the emergency cooling water storage unit 1025 may vary depending on the design of the nuclear power plant 100. In FIG. 1, an emergency cooling water storage portion 1025 is provided outside the storage portion 103. The emergency cooling water storage portion 1025 has an opening portion 1025a for discharging steam formed by the evaporation of the cooling water. The opening 1025a may be formed on the upper portion of the emergency cooling water storage portion 1025 as shown in FIG.

The emergency cooling water storage unit 1025 is an optional configuration. When the air-cooling type is adopted according to the design of the nuclear power plant 100, the driven residual heat removal system 1020 may not include the emergency cooling water storage portion 1025.

The circulation pipes 1026 and 1027 include a first circulation pipe 1026 and a second circulation pipe 1027. The first circulation pipe 1026 and the second circulation pipe 1027 are connected to different places of the emergency cooling water storage unit 1025 and the condensation heat exchanger 1021. Circulating piping 1026 and 1027 are for circulating the cooling water stored in the emergency cooling water storage portion 1025. [ During operation of the driven residual heat elimination system 1020 or the depressurization facility 1030, the cooling water circulates continuously through the circulation piping 1026, 1027 to the emergency cooling water reservoir 1025 and the condensation heat exchanger 1021.

The first circulation pipe 1026 forms a flow path for supplying the cooling water of the emergency cooling water storage unit 1025 to the condensation heat exchanger 1021. The first circulation pipe 1026 is connected to the lower portion of the emergency cooling water storage portion 1025 and the lower portion of the condensation heat exchanger 1021.

The second circulation pipe 1027 forms a flow path for recovering the cooling water heated in the condensation heat exchanger 1021 to the emergency cooling water storage part 1025. The second circulation pipe 1027 is connected to the upper portion of the condensation heat exchanger 1021 and the emergency cooling water storage portion 1025 and the connection position of the emergency cooling water storage portion 1025 is higher than the connection position of the first circulation pipe 1026 .

The first circulation pipe 1026 is provided with an isolation valve 1026a and a check valve 1026b. The second circulation pipe 1027 is provided with an isolation valve 1027a. The isolation valve 1026a of the first circulation pipe 1026 and the isolation valve 1027a of the second circulation pipe 1027 are for maintenance and repair of the driven residual heat removal system 1020. [ Normally, the isolation valves 1026a and 1027a are opened and closed at a time when maintenance and repair are required. The check valve 1026b provided in the first circulation pipe 1026 is configured so as to pass only the flow in the direction of the arrow and to prevent the reverse flow of the cooling water.

The first circulation pipe 1026 and the second circulation pipe 1027 may be provided with a flow path resistance region. The flow path resistance region forms a flow path resistance larger than that of the other regions, so that the flow of the cooling water can be stabilized. However, it is necessary to increase the size of the condensation heat exchanger 1021 to compensate for the loss of the heat transfer amount due to the reduction in the flow passage.

The cooling water stored in the emergency cooling water storage portion 1025 is heated while circulating the condensation heat exchanger 1021 continuously through the circulation pipes 1026 and 1027. [ The heated cooling water evaporates and becomes steam, and the steam is discharged through the opening 1025a to the outside of the final heat sink cause.

The depressurization facility 1030 has operating conditions of high temperature and high pressure. Therefore, in order for the condensation heat exchanger 1021 of the passive residual heat removal system 1020 to be utilized in the nuclear reactor coolant system decompression system 1000, it must have durability against the operating conditions of the decompression facility 1030. In general, the driven residual heat removal system 1020 uses a primary fluid or a secondary fluid, and acts as a pressure boundary with the primary system or the secondary system, so that it is designed to have durability against high temperature and high pressure environments. Therefore, the condensation heat exchanger 1021 of the driven residual heat removal system 1020 can be utilized in the reactor coolant system depressurization system 1000.

The depressurization facility 1030 performs a pressurizer safety valve function and a safety depressurization function. The pressurizer safety valve function is a function for suppressing the pressure rise when the pressure of the reactor coolant system (101) rises sharply. The safety decompression function is a function of the reactor coolant system 101 when the reactor coolant system 101 is maintained at a high temperature and a high pressure state due to an excessive design standard such as a loss of non-coolant accident, To reduce the pressure.

1, the depressurization facility 1030 is configured to prevent the overpressure of the reactor coolant system 101 by using the condensation heat exchanger 1021 of the driven residual heat elimination system 1020. As shown in FIG. The depressurization facility 1030 includes a depressurization line 1031, an injection line 1032, depressurization valves 1033a and 1033b, and a pressurization safety valve 1035. [

The decompression piping 1031 is connected to the reactor coolant system 101 and the condensation heat exchanger 1021 so as to supply the steam discharged from the reactor coolant system 101 to the condensation heat exchanger 1021. The pressure reducing pipe 1031 is connected to the inlet header of the condensing heat exchanger 1021.

At least a partial area of the pressure reducing pipe 1031 may be composed of a plurality of fork 1031a and 1031b. For example, the pressure reducing pipe 1031 may be connected to the pressurizer 1010 by a single pipe as shown in Fig. 1, and may be branched into bifurcations 1031a and 1031b in the inner space of the compartment 103. Fig. The decompression pipes 1031 of the bifurcations 1031a and 1031b can be joined to the condensing heat exchanger 1021 by joining them with a single pipe. The pressure reducing pipe 1031 may be joined to the steam pipe 1022 of the driven residual heat removing system 1020 before being connected to the condensation heat exchanger 1021. [

In the present invention, various structures can be considered that the pressure reducing pipe 1031 or the injection pipe 1032 is composed of a plurality of forklifts 1031a and 1031b. The description of the injection piping 1032 related to the plurality of forkings 1031a and 1031b may be overlapped with the description of the pressure reducing piping 1031. [ The description of the injection piping 1032 related to the plurality of fork 1031a and 1031b is replaced with a description of the decompression pipe 1031 connected from the pusher 1010 to the condensing heat exchanger 1021. [ The following description is equally applicable to a pilot-driven safety relief valve (see Figs. 7 and 8) to be described later.

(1) Pressurizer: Part of the decompression pipe: Condensation heat exchanger = Single pipe: Multiple pipe: Single pipe

A single depressurization pipe 1031 is connected to the pressurizer 1010 and is divided into a plurality of fork 1031a and 1031b in a partial region of the depressurization pipe 1031 and then a plurality of fork 1031a, 1031b are joined to a single pipe and then connected to the condensing heat exchanger 1021 as a single pipe. (1) can be understood as a structure shown in Fig. 1 and the like.

(2) Pressurizer: partial area of decompression piping: condensation heat exchanger = plural fork: plural fork: single pipe

(2), a plurality of pipes are connected to a pressurizer, a plurality of pipes continue to be joined and joined to a single pipe before being connected to a condensation heat exchanger, and then connected to a condensing heat exchanger as a single pipe. (2) can be understood as the structures shown in Figs. 7 and 8 and the like.

(3) Pressurizer: Part of the decompression piping: Condensation heat exchanger = (Single piping: Single piping: Single piping) × n (n is a natural number of 2 or more)

The configuration of the condenser 3 is a configuration in which a single pipe is connected from the pressurizer 1010 to the condensing heat exchanger 1021 and the pressure reducing pipes 1031 are connected to the plurality of condensing heat exchangers 1021 one by one. (3) can be understood as a structure in which both the left side and the right side of FIG. 2 are combined.

The injection piping 1032 is connected to the condensing heat exchanger 1021 and the reactor coolant system 101 to inject the condensate formed in the condensing heat exchanger 1021 into the reactor coolant system 101. The injection piping 1032 may be connected to the outlet header of the condensation heat exchanger 1021. The injection piping 1032 may be branched from the water supply piping 1023 of the driven residual heat removal system 1020. The injection piping 1032 may be provided with an isolation valve and a check valve. The isolation valve provided in the injection pipe 1032 is closed during normal operation of the nuclear power plant 100 and during operation of the driven residual heat elimination system 1020 and is opened upon operation of the decompression facility 1030. The check valve provided in the injection pipe 1032 is made to pass only one directional flow and prevents the coolant from flowing backward from the reactor coolant system 101 to the injection pipe 1032.

The depressurization valves 1033a and 1033b (DV) are installed in the depressurization piping 1031 or the injection piping 1032. Referring to Fig. 1, the pressure reducing valves 1033a and 1033b are installed in the pressure reducing pipe 1031. Fig. In the case where at least a partial area of the pressure reducing pipe 1031 is composed of a plurality of fork 1031a and 1031b, at least one pressure reducing valve 1033a and 1033b may be provided for each of the plurality of fork 1031a and 1031b.

The safety relief function described above can be implemented by the pressure reducing valves 1033a and 1033b. When the operator inputs an operation signal, the pressure reducing valves 1033a and 1033b are opened by a driving force such as electric power. When the decompression valves 1033a and 1033b are opened by the judgment of the operator, the coolant (steam) of the reactor coolant system 101 is discharged through the decompression pipe 1031 so that the pressure rise of the reactor coolant system 101 can be suppressed have.

A pressurizer safety valve (PSV) is installed in the pressurizer safety pipe (1034). The pressurizer safety line 1034 is connected to the pressurizer 1010 and the reactor drain tank (RDT) 1074. The pressurizer safety valve 1035 is opened and closed based on a predetermined pressure to suppress a sudden pressure rise of the reactor coolant system 101. [

The pressurizer safety valve function described above can be implemented by the pressurizer safety valve 1035. [ The pressurizer safety valve 1035 is opened and closed by the force of the spring and the pressure difference of the reactor coolant system 101. When the pressure of the reactor coolant system 101 becomes higher than the reference pressure, the pressurizer safety valve 1035 is opened, and when the pressure of the reactor coolant system 101 becomes lower than the reference pressure, the pressurizer safety valve 1035 is closed. When the pressurizer safety valve 1035 is opened by the pressure difference, the coolant (vapor) in the reactor coolant system 101 is discharged to the reactor drainage tank 107 through the pressurizer safety pipe 1034, The rise can be suppressed.

A condensate receiving portion 1036 may be installed in the injection pipe 1032. The condensate storage portion 1036 is formed to store the condensed water discharged from the condensation heat exchanger 1021. The condensate receiving portion 1036 may be implemented in the form of a tank or a water tank. The condensate receiving portion 1036 is for maintaining the decompression capability of the depressurization facility 1030 for a required time.

When the depressurization facility 1030 operates for a long time, the depressurization facility 1030 forms a pressure-type with the reactor coolant system 101. When the depressurization facility 1030 forms a pressure balance with the reactor coolant system 101, the condensed water collected in the condensate water receiving portion 1036 is injected into the reactor coolant system 101 by the gravity head.

The condensate receiving portion 1036 is an optional configuration. If the depressurizing capability of the condensing heat exchanger 1021 is sufficiently high depending on the characteristics of the nuclear power plant 100, the depressurization facility 1030 may not include the condensed water accommodating portion 1036.

The depressurization facility 1030 may further include a rupture plate (not shown) or an air release isolation valve (not shown).

The depressurization facility 1030 includes a closed channel consisting of a reactor coolant system 101, a depressurization piping 1031, a condensation heat exchanger 1021, an injection piping 1032 and a condensed water accommodating portion 1036. If the pressure of the closed channel excessively increases, the pressure reducing equipment 1030 may lose the pressure reducing capability. The rupture disk or the air release isolation valve is for protecting the decompression facility 1030 and for recovering the decompression capability.

The installation position of the rupture plate or the air discharge isolation valve may vary depending on the design of the nuclear reactor 100. For example, the rupture plate or the air discharge isolation valve may be installed between 1) the pressure reducing valve 1033a, 1033b in the pressure reducing pipe 1031 and the condensing heat exchanger 1021, or 2) the condensing heat exchanger 1021 ) And the condensed water receiving portion 1036, or 3) installed in the condensed water receiving portion 1036.

The rupture plate ruptures when the pressure of the closing passage rises above a predetermined reference. When the pressure of the closed channel rises above a predetermined reference, the atmosphere release valve is opened by the judgment of the operator.

The depressurization facility 1030 may further include non-condensable gas exhaust piping (not shown).

The non-condensable gas exhaust piping is configured to remove non-condensable gas flowing through the injection piping 1032. The installation position of the non-condensable gas exhaust pipe may vary depending on the design of the nuclear power plant 100. For example, the non-condensable gas exhaust piping may include: 1) a lower portion (outlet header) of the condensation heat exchanger 1021, 2) an upper portion of the condensate receiving portion 1036, or 3) a condensing heat exchanger 1021 Condensate receiving portion 1036. [0064]

When the non-condensable gas exists in the flow path of the depressurization facility 1030, the heat transfer performance may be greatly reduced in the latter period of operation of the depressurization facility 1030 where the pressure of the reactor coolant system 101 is reduced to the atmospheric pressure level. Non-condensable gas exhaust piping can discharge the non-condensable gas from the flow path of the depressurization facility 1030, so that deterioration of the heat transfer performance can be suppressed.

The depressurization facility 1030 operates when all of the driven residual heat removal systems 1020 are not operating. Therefore, even if the depressurization facility 1030 and the driven residual heat removal system 1020 have a structure sharing the condensation heat exchanger 1021, the depressurization facility 1030 and the driven residual heat removal system 1020 do not mutually interfere.

Hereinafter, the operation of the passive residual heat elimination system 1020 or the reactor coolant system decompression system 1000 when a virtual accident occurs in the nuclear power plant 100 will be described.

FIG. 2 is a conceptual view showing the operation state of the passive residual heat elimination system 1020 or the reactor coolant system decompression system 1000 in the event of a virtual accident in the nuclear power plant 100 shown in FIG.

On the left side of the middle dotted line, the driven residual heat elimination system 1020 is shown in a state where the driven residual heat elimination system 1020 operates normally in the event of an accident. And the right side of the dotted line shows the reactor coolant system decompression system 1000 in a state in which all of the passive residual heat removal system 1020 at the time of an accident does not operate. For the sake of convenience, the pressurizer safety pipe 1034 and the pressurizer safety valve 1035 are shown on the left side.

First, referring to the left side of FIG. 2, the driven residual heat removal system 1020 operates when an accident requiring the operation of the driven residual heat elimination system 1020 in the nuclear power plant 100 occurs. The isolation valves 104b and 105b provided in the main water pipe 104a and the main pipe 105a are closed and the isolation valves 1022a and 1023a provided in the steam pipe 1022 and the water pipe 1023 are opened. The steam generated in the steam generator 102 is in turn supplied to the condensing heat exchanger 1021 through the main steam pipe 105a and the steam pipe 1022. [ The cooling water in the emergency cooling water storage unit 1025 is also supplied to the condensation heat exchanger 1021 through the first circulation pipe 1026.

In the condensation heat exchanger 1021, heat exchange is performed between the steam and the cooling water, the steam is cooled, and the cooling water is heated. The steam is condensed to form condensate, which in turn is supplied to the steam generator 102 via the feed water pipe 1023 and the main feed pipe 104a. The heated cooling water is recovered to the emergency cooling water storage portion 1025 through the second circulation pipe 1027. The continuously heated cooling water is evaporated and discharged to the outside through the opening 1025a. The sensible heat of the reactor coolant system 101 and the residual heat of the core 101a are removed by the operation of the passive residual heat removal system 1020. [

Next, referring to the right side of FIG. 2, it can be seen that, when a total loss of residual heat (an accident that requires operation of the residual heat removal equipment, such as a complete water supply system loss accident or a complete loss of secondary system heat removal, And the residual heat removal system such as the residual heat removal system 1020 does not operate), the depressurization facility 1030 operates when the driven residual heat removal system 1020 is disabled. The isolation valves 1022a and 1023a provided in the steam pipe 1022 and the water supply pipe 1023 are closed and the decompression valves 1033a and 1033b provided in the decompression pipe 1031 and the isolation valve 1032a provided in the injection pipe 1032 are closed, Is opened. The steam is discharged from the pressurizer 1010 through the pressure reducing pipe 1031 and is supplied to the condensing heat exchanger 1021 through the pressure reducing valves 1033a and 1033b.

The cooling water for cooling the steam is supplied from the emergency cooling water storage portion 1025. The steam is cooled and condensed by the cooling water in the condensing heat exchanger 1021 to form condensed water. The condensate is cumulatively collected in the condensate receiving portion 1036 through the injection pipe 1032.

The pressurizer safety valve 1035 is also opened or closed in response to the pressure change of the reactor coolant system 101 to suppress the sudden pressure rise of the reactor coolant system 101. When the pressure of the reactor coolant system 101 rises above a predetermined reference, the pressurizer safety valve 1035 is opened. The steam is discharged from the pressurizer 1010 and through the pressurizer safety valve 1035 to the reactor drainage tank 107. When the pressure of the reactor coolant system 101 falls below a predetermined reference level, the pressurizer safety valve 1035 closes and the vapor stops being released. As the pressure of the reactor coolant system 101 increases and the pressure decreases, 1035 may be repeatedly opened and closed. In general, when the operation of the pressurizer safety valve 1035 is repeated, the pressure reducing valves 1033a and 1033b are opened.

The pressure rise of the reactor coolant system 101 can be suppressed by the operation of the pressure reducing valves 1033a and 1033b and the pressurizing device safety valve 1035. [ Generally, when the decompression valves 1033a and 1033b are operated, the reactor coolant system 101 is decompressed, and the pressurizer safety valve 1035 stops operating.

When the pressure reducing equipments 1030 and the reactor coolant system 101 form pressure equilibrium over time, the condensed water collected in the condensed water receiving portion 1036 is injected into the reactor coolant system 101 through the injection pipe 1032 do. When the reactor coolant system 101 and the pressure reducing apparatus 1030 are pressure balanced, the condensed water collected in the condensed water receiving portion 1036 is injected into the reactor coolant system 101 by gravity, And performs the passive residual heat eliminating function while circulating the coolant system 101 and the reduced pressure facility 1030. The safe decompression function continues until the operator closes the decompression valves 1033a and 1033b.

In the initial stage of operation of the reactor coolant system depressurization system 1000 as described above, steam emitted from the reactor coolant system 101 is quickly condensed in the condensation heat exchanger 1021 and stored in the condensed water accommodating portion 1036. Thus, the reactor coolant system depressurization system 1000 can quickly depressurize the pressure of the reactor coolant system 101. Also, when the reactor coolant system decompression system 1000 is continuously operated, the reactor coolant system 101 and the decompression apparatus 1030 are pressure balanced, and the condensed water lowers the pressure of the reactor coolant system 101 through long-term natural circulation Remove the residual heat. Thus, the reactor coolant system depressurization system 1000 can safely maintain the reactor coolant system 101.

Condensate formed by the operation of the reactor coolant system depressurization system 1000 continuously circulates through the reactor coolant system 101 and the depressurization facility 1030. Therefore, even when a complete loss of residual heat removal system such as a complete water loss accident (domestic commercial nuclear power plant) or a secondary system heat removal complete failure (domestic SMART) occurs, the overpressure accident of the reactor coolant system 101 causes the coolant It is possible to prevent the accident from spreading to the accident and to simplify the follow-up action.

In addition, the reactor coolant system decompression system 1000 of the present invention shares the passive residual heat elimination system 1020 with the condensation heat exchanger 1021, so that facility cost can be minimized.

1 and 2, the description has been limited to the open type driven residual heat elimination system 1020 in which the condensation heat exchanger 1021 is installed only inside the compartment 103. However, However, the driven residual heat removal system 1020 may be configured as a circulation type or an air-cooling type depending on the characteristics of the nuclear power plant. The cooling heat exchanger of the circulating type driven residual heat elimination system is installed both inside and outside the compartment, and the air-cooled type of residual heat elimination system does not have the emergency cooling water storage part 1025. The present invention is not necessarily limited to the open passive residual heat removal system.

Hereinafter, other embodiments of the present invention will be described. The overlapping description in each embodiment is the same as that described above.

3 is a conceptual view showing a normal operation state of a nuclear reactor coolant system depressurization system 1100 and a nuclear power plant 110 having the same according to a second embodiment of the present invention. 4 is a conceptual view showing the operating state of the passive residual heat eliminating system 1120 or the reactor coolant system depressurizing system 1100 in the event of a virtual accident in the nuclear power plant 110 shown in FIG.

The nuclear power plant 110 includes a Passive Safety Injection System (PSIS).

The passive safety injection system 118 is for maintaining the coolant level of the reactor coolant system 111. When a coolant loss accident occurs, the coolant level in the reactor coolant system 111 gradually decreases. When the coolant level in the reactor coolant system 111 is lowered due to a coolant accident or the like, the passive safety injection system 118 injects the stored coolant into the reactor coolant system 111.

The passive safety injection system 118 may include various tanks for injecting coolant using natural forces such as a core filler tank (not shown) and a safety filler tank (not shown). Each tank is connected to a reactor coolant system 111 by a safety injection piping 118a. The safety infusion piping 118a forms an inflow passage for the coolant. The safety injection pipe 118a may be provided with check valves 118b for preventing the backflow of the coolant.

The injection piping 1132 is connected to the safety injection piping 118a, not directly to the reactor coolant system 111. [ As a result, the injection piping 1132 is connected to the reactor coolant system 111 via the safety injection piping 118a.

The condensing heat exchanger 1121 shown in Figs. 3 and 4 corresponds to a shell and tube heat exchanger.

The shell and tube heat exchanger includes a shell and a tube. The shell means the outside of the tube. The shell and the tube form a first flow path and a second flow path which are separated from each other. A first flow path is formed in the inner space of the tube, and a second flow path is formed in the shell between the tubes. And the second flow path corresponds to a space between the outer circumferential surfaces of the tubes. In some cases, the condensation heat exchanger 1121 may have an outer tube that surrounds the entire tube. In this case, the second flow path corresponds to a space between the outer peripheral surfaces of the tubes inside the outer casing of the condensing heat exchanger 1121.

Generally, in the first flow path, steam that flows from the reactor coolant system 111 or the steam generator 112 flows. The cooling water supplied from the emergency cooling water storage portion 1125 flows in the second flow path. If it is an air-cooled type demagnetizing system 1120, an external atmosphere will flow through the second flow path. However, depending on the characteristics of the nuclear reactor 110, the fluid flowing through the first flow path and the fluid flowing through the second flow path may be opposite to each other.

The pressure reducing pipe 1131 is connected to the inlet header of the condensing heat exchanger 1121. In the case where the steam discharged from the reactor coolant system 111 or the steam generator 112 flows toward the shell, the inlet header may not be installed in the second flow path depending on the characteristics of the nuclear power plant 110, (1131) may be directly connected to the outer tube of the condensation heat exchanger (1121).

The condensation heat exchanger 1121 is provided outside the compartment 113 and is disposed inside the emergency cooling water reservoir 1125. As the condensation heat exchanger 1121 is disposed in the emergency cooling water storage 1125, the flow path configuration is changed. First, the first and second circulation pipes 1026 and 1027 described in FIGS. 1 and 2 are removed. At least a part of the decompression pipe 1131, the injection pipe 1132, the steam pipe 1122 and the water pipe 1123 can pass through the storage part 113 and the emergency cooling water storage part 1125.

5 is a conceptual view showing a normal operation state of a nuclear reactor coolant system depressurization system 1200 and a nuclear power plant 120 having the same according to a third embodiment of the present invention.

The passive residual heat eliminating system 1220 shown in FIG. 5 is connected to the reactor coolant system 121 to circulate the primary fluid. The passive residual heat removal system 1220 is independent of the steam generator 122.

Since the driven residual heat elimination system 1220 is arranged to circulate the primary fluid, the decompression pipe 1231 and the steam pipe 1222 are not separated from each other but formed of one pipe. The pressure reducing pipe 1231 corresponds to the steam pipe 1222 and the steam pipe 1222 corresponds to the pressure reducing pipe 1231. The pressure reducing pipe 1231 or the steam pipe 1222 is connected to the pressurizer 1210 and the condensing heat exchanger 1221. In the structure in which the driven residual heat removing system 1220 is configured to circulate the primary fluid, an isolation valve may not be provided in the pressure reducing pipe 1231 or the steam pipe 1222.

The pressure reducing valves 1233a and 1033b are installed in the injection pipe 1232. At least a partial region of the injection pipe 1232 may be composed of a plurality of fork 1232a and 1232b. A plurality of forkings 1232a and 1232b may be branched from the water supply pipe 1223. [ At least one pressure reducing valves 1233a and 1233b may be provided for each of the plurality of fork 1232a and 1232b.

FIG. 6 is a conceptual view showing the operating state of the passive residual heat eliminating system 1220 or the reactor coolant system depressurizing system 1200 at the occurrence of a virtual accident in the nuclear power plant 120 shown in FIG.

On the left side of the middle dotted line, the driven residual heat elimination system 1220 is shown in a state where the driven residual heat elimination system 1220 operates normally in the event of an accident. And the right side of the dotted line shows the reactor coolant system decompression system 1200 in a state in which all of the passive residual heat elimination system 1220 at the time of the accident is not operated. For convenience, the pressurizer safety pipe 1234 and the pressurizer safety valve 1235 are shown on the left.

First, referring to the left side of FIG. 6, the driven residual heat removal system 1220 operates when an accident that requires operation of the driven residual heat removal system 1220 in the nuclear power plant 120 occurs. The isolation valves 124b and 125b provided in the main water supply pipe 124a and the main combustion chamber 125a are closed and the isolation valve 1223a provided in the water supply pipe 1223 is opened. The steam generated in the reactor coolant system 121 is supplied to the condensation heat exchanger 1221 through the steam pipe 1222 or the reduced pressure pipe 1231. The cooling water in the emergency cooling water storage unit 1225 is also supplied to the condensation heat exchanger 1221 through the first circulation pipe 1226.

In the condensation heat exchanger 1221, heat exchange is performed between the steam and the cooling water, the steam is cooled, and the cooling water is heated. The steam is condensed to form condensate and is supplied to the reactor coolant system 121 via the feed water line 1223. The heated cooling water is recovered to the emergency cooling water storage portion 1225 through the second circulation pipe 1227. The continuously heated cooling water is evaporated and discharged to the outside through the opening 1225a. The sensible heat of the reactor coolant system 121 and the residual heat of the core 121a are removed by the operation of the driven residual heat elimination system 1220. [

Next, referring to the right side of FIG. 6, it can be seen that, in the event of a complete loss of residual heat (an accident that requires operation of the residual heat removal equipment, such as a complete water supply system failure or a complete loss of secondary system heat, And the residual heat removal system such as the residual heat removal system 1220 does not operate), the depressurization facility 1230 operates when the driven residual heat removal system 1220 becomes inoperable. The isolation valve 1223a provided in the water supply pipe 1223 is closed and the pressure reducing valves 1233a and 1233b provided in the injection pipe 1232 are opened. The steam is discharged from the pressurizer 1210 through the pressure reducing pipe 1231 or the steam pipe 1222 and is supplied to the condensing heat exchanger 1221 through the pressure reducing pipe 1231. [

The cooling water is supplied from the emergency cooling water storage section 1225 to the condensation heat exchanger 1221. The steam is cooled and condensed by the cooling water in the condensation heat exchanger 1221 to form condensed water. The condensed water passes through the pressure reducing valves 1233a and 1233b and is accumulated in the condensed water receiving portion 1236 cumulatively. Also, the pressurizer safety valve 1235 is opened or closed in accordance with the pressure change of the reactor coolant system 121 to suppress the sudden pressure rise of the reactor coolant system 121. The pressure rise of the reactor coolant system 121 can be suppressed by the operation of the depressurization facility 1230. [

The condensed water stored in the condensed water receiving portion 1236 is injected into the reactor coolant system 121 through the injection piping 1232 when the decompression facility 1230 and the reactor coolant system 121 form pressure equilibrium . The condensed water stored in the condensed water accommodating portion 1236 after pressure equalization between the reactor coolant system 121 and the reduced pressure facility 1230 is injected into the reactor coolant system 121 by gravity and the reactor coolant is introduced into the reactor coolant system 121 by natural circulation, System 121 and the decompression facility 1230 while performing a passive residual heat eliminating function.

FIG. 7 is a conceptual view showing a normal operation state of a nuclear reactor coolant system depressurization system 1300 and a nuclear power plant 130 having the nuclear reactor coolant system according to a fourth embodiment of the present invention. FIG. 8 is a conceptual view showing the operation state of the passive residual heat eliminating system 1320 or the reactor coolant system decompression system 1300 in the event of a virtual accident in the nuclear power plant 130 shown in FIG.

The depressurization facility 1330 includes a pilot operated safety relief valve 1337 (POSRV) installed in the depressurization pipe 1331. The pilot operated safe release valve 1337 includes a first valve 1337a that performs a function of a pressurizer safety valve 1335 and a second valve 1337b that performs a safety depressurization function. Pilot-operated safety relief valve 1337 performs both the functions of pressure relief valve 1335 and pressure relief valves 1333a and 1033b substantially as previously described.

The first valve 1337a may be driven by a spring, in which case the first valve 1337a may be referred to as a spring-loaded pilot-actuated valve. The first valve 1337a is configured to suppress an abrupt pressure rise of the reactor coolant system 131. [ The first valve 1337a can be opened by a spring when the pressure of the reactor coolant system 131 rises sharply and becomes higher than a preset reference. The second valve 1337b can be closed if the pressure of the reactor coolant system 131 becomes lower than a preset reference.

The second valve 1337b may be driven by an electric motor, in which case the second valve 1337b may be referred to as a motor drive pilot valve. The second valve 1337b operates upon occurrence of a design basis excess accident in which the function of all the driven residual heat elimination system 1320 is lost, thereby lowering the pressure of the reactor coolant system 131. [ When the residual heat removal system of the nuclear power plant 130 is lost and the reactor coolant system 131 is maintained in a high temperature and high pressure state, the second valve 1337b is driven by the electric motor and is opened.

At least a partial area of the pressure reducing pipe 1331 may be composed of a plurality of forkings 1331a and 1331b. Referring to FIG. 7, a plurality of prongs 1331a and 1331b may mean that a plurality of prestressing pipes 1331 are connected to a single pusher 1310, unlike the prongs 1331a and 1331b shown in FIGS. The structure of Fig. 7 corresponds to the structure of (2) described in Fig.

The pilot drive safe discharge valve 1337 may be provided for each of a plurality of forkings 1331a and 1331b. The decompression pipe 1331 formed of a plurality of forkings 1331a and 1331b is divided into a fork provided with the first valve 1337a and a fork provided with the second valve 1337b for each of the forked portions. The branch where the first valve 1337a is installed is connected to the reactor drainage tank 137. The branch where the second valve 1337b is installed is connected to the condensation heat exchanger 1321.

9 is a conceptual view showing a normal operation state of a nuclear reactor coolant system depressurization system 1400 and a nuclear power plant 140 having the same according to a fifth embodiment of the present invention. FIG. 10 is a concept view showing the operation state of the passive residual heat elimination system 1420 or the reactor coolant system depressurization system 1400 in the event of a virtual accident in the nuclear power plant 140 shown in FIG.

The condensate receiving portion 1036 (see FIG. 1) is an optional configuration. The depressurization facility 1430 may not include the condensate storage portion 1036 when the decompression capacity of the condensation heat exchanger 1421 is sufficient depending on the characteristics of the nuclear power plant 140. [ The depressurization equipment 1430 shown in Figs. 9 and 10 does not include the condensed water accommodating portion 1036. Fig.

The decompression facility 1430 that does not include the condensate storage portion 1036 is prematurely in equilibrium with the reactor coolant system 141. Accordingly, the condensed water formed in the condensation heat exchanger 1421 is injected into the reactor coolant system 141 in an early stage, and the remaining heat is removed by continuously circulating the reactor coolant system 141 and the reduced-pressure facility 1430.

11 is a conceptual view showing a normal operation state of a nuclear reactor coolant system depressurization system 1500 and a nuclear power plant 150 having the same according to a sixth embodiment of the present invention. 12 is a conceptual view showing the operating state of the passive residual heat removing system 1520 or the reactor coolant system depressurizing system 1500 at the occurrence of a virtual accident in the nuclear power plant 150 shown in FIG.

The emergency cooling water storage portion 1525 is installed inside the storage portion 153. In this case, even if the cooling water in the emergency cooling water storage portion 1525 is evaporated, it is not discharged to the outside but is discharged to the inner space of the storage portion 153. The discharged vapors are cooled and condensed by the equivalent copper cooling system (156).

The condensation heat exchanger 1521 is disposed inside the emergency cooling water storage portion 1525. The condensation heat exchanger 1521 shown in Figs. 11 and 12 corresponds to a plate heat exchanger. When the condensation heat exchanger 1521 is disposed inside the emergency cooling water storage 1525, an open flow path can be applied to the condensation heat exchanger 1521 to facilitate natural circulation. The open flow path refers to a configuration in which fluids can flow in and out of the outer side surface in addition to the top and bottom direction inlet and outlet of the condensation heat exchanger 1521.

Since the emergency cooling water storage 1525 is installed inside the compartment 153 and the condensation heat exchanger 1521 is installed inside the emergency cooling water storage 1525, the flow path configuration is different from the embodiments described above. First, the first and second circulation pipes 1026 and 1027 (see FIG. 1) are removed as the condensation heat exchanger 1521 is installed inside the emergency cooling water storage unit 1525. At least a part of the decompression pipe 1531, the injection pipe 1532, the steam pipe 1522 and the water pipe 1523 penetrate the emergency cooling water storage 1525.

13 is a conceptual view showing a normal operation state of a nuclear reactor coolant system depressurization system 1600 and a nuclear power plant 160 having the same according to a seventh embodiment of the present invention. FIG. 14 is a concept view showing the operation state of the passive residual heat eliminating system 1620 or the reactor coolant system decompression system 1600 in the event of a virtual accident in the nuclear power plant 160 shown in FIG.

The emergency cooling water storage portion 1625 is installed inside the storage portion 163.

The condensation heat exchanger 1621 is installed inside the emergency cooling water storage portion 1625.

The pressure reducing valves 1633a and 1633b are installed in the injection pipe 1632. In this case, the pressure reducing pipe 1631 becomes the steam pipe 1622, and the steam pipe 1622 becomes the pressure reducing pipe 1631.

15 is a conceptual view showing a normal operation state of a nuclear reactor coolant system depressurization system 1700 and a nuclear power plant 170 having the same according to an eighth embodiment of the present invention. FIG. 16 is a concept view showing the operation state of the passive residual heat eliminating system 1720 or the reactor coolant system decompression system 1700 in the event of a virtual accident in the nuclear power plant 170 shown in FIG.

The compartment cooling system or equivalent dispensing cooling system 176 includes a condensate recovery unit 176a.

The condensate recovery unit 176a is connected to the emergency cooling water storage unit 1725. [ The condensed water formed by the operation of the compartment cooling system or the dispensed cooling system 176 is recovered to the emergency cooling water reservoir 1725 through the condensate recovery unit 176a. The water level of the emergency cooling water storage portion 1725 can be maintained at an appropriate water level by the condensed water recovered through the condensate water recovery portion 176a.

The cooling water sprinkled in the sprinkling water sprinkling system (not shown) as well as the vapor evaporated in the emergency cooling water storage portion 1725 are recovered to the emergency cooling water storage portion 1725 as well as the storage portion cooling system or the aspirated water cooling system 176 . The water level of the emergency cooling water storage portion 1725 can be maintained at an appropriate water level by the recovered cooling water or steam.

The condensate receiving portion 1036 (see FIG. 1) is not provided in the injection pipe 1732.

The injection pipe 1732 is branched from the water supply pipe 1723 and connected to the water supply pipe 1723 again. The injection pipe 1732 is connected to an area between the isolation valve 1723a provided in the water supply pipe 1723 and the check valve 1723b. The check valve 1723b provided in the water supply pipe 1723 prevents the coolant from flowing back to the water supply pipe 1723 and also prevents the coolant from flowing back into the injection pipe 1732. [ Therefore, a separate check valve may not be installed in the injection pipe 1732.

17 is a conceptual view showing a normal operation state of a nuclear reactor coolant system depressurization system 1800 and a nuclear power plant 180 having the same according to a ninth embodiment of the present invention. FIG. 18 is a conceptual view showing the operation state of the passive residual heat eliminating system 1820 or the reactor coolant system decompression system 1800 at the occurrence of a virtual accident in the nuclear power plant 180 shown in FIG.

The pressure reducing pipe 1831 is composed of a plurality of fork 1831a and 1831b. A plurality of pipes are connected to the pressurizer 1810 and the plurality of pipes continue to be joined to the single pipe before being connected to the condensing heat exchanger 1821 and then connected to the condensing heat exchanger 1821 as a single pipe. The pressure reducing pipe 1831 shown in Figs. 17 and 18 can be understood as the constitution (2) explained in Fig.

19 is a conceptual view showing a normal operation state of a nuclear reactor coolant system depressurization system 1900 and a nuclear power plant 190 having the same according to a tenth embodiment of the present invention. 20 is a conceptual view showing the operation state of the passive residual heat eliminating system 1920 or the reactor coolant system decompression system 1900 in the event of a virtual accident in the nuclear power plant 190 shown in FIG.

The nuclear power plant 190 includes automatic decompression pipes 1928a and 1928b and automatic decompression valves 1929a and 1929b.

The automatic decompression pipes 1928a and 1928b are connected to the nuclear reactor coolant system 191 and the nuclear reactor internal building water storage tank 198 (IRWST; In-containment Refueling Water Storage Tank). The automatic decompression piping 1928a and 1928b may be branched from the decompression piping 1931 and connected to the reactor building internal storage tank 198 as shown in Figs.

The automatic pressure reducing valves 1929a and 1929b are installed in the automatic pressure reducing pipes 1928a and 1928b. The automatic pressure reducing valves 1929a and 1929b are generally part of the safety system and operate with the operation of the relevant safety system. When the pressure of the reactor coolant system 191 reaches the operating set value of the automatic pressure reducing valves 1929a and 1929b in the event of an accident, the automatic pressure reducing valves 1929a and 1929b are automatically opened.

In the case of the nuclear reactor 190 to which the automatic pressure reducing valves 1929a and 1929b are applied, the passive residual heat eliminating system 1920 and the automatic pressure reducing valves 1929a and 1929b may interfere with each other. However, the nuclear power plants 190 constructed as shown in Figs. 19 and 20 can avoid mutual interference.

As described above, the present invention can fundamentally exclude the overpressure accident of the reactor coolant system due to the loss of the coolant, thereby facilitating the operator's judgment and action. In addition, the safety of the nuclear power plant is strengthened by implementing the decompression facility that can be operated by the judgment of the operator in conjunction with the condensation heat exchanger of the passive residual heat removal system. The sharing of the condensation heat exchanger with the decompression facility and the drift eliminator system helps to improve the economics of nuclear power plants. Particularly, the plate type heat exchanger has a high degree of heat exchange performance and durability against high temperature and high pressure and can be easily utilized as a condensation heat exchanger.

The reactor coolant system depressurization system and the nuclear power plant 190 having the nuclear reactor coolant system described above are not limited to the configurations and the methods of the embodiments described above, but the embodiments can be applied to all or some of the embodiments May be selectively combined.

1. First Embodiment (Figs. 1 and 2)
100: Nuclear power plant
101: reactor coolant system, 102: steam generator, 103: storage part, 104: water supply system, 105: turbine system, 106: passive containment building cooling system, 107:
1000: Reactor coolant system decompression system
1010: Presser
1020: Passive residual heat removal system
A first circulation pipe, 1027 a second circulation pipe, a second circulation pipe, and a second circulation pipe,
1030: Pressure reducing equipment
1031: decompression piping, 1032: injection piping, 1033: decompression valve, 1034: pressurizer safety pipe, 1035: pressurizer safety valve, 1036:
2. Second Embodiment (Figs. 3 to 4)
The same reference numerals as those in Figs. 1 to 2 are given as follows.
110: Nuclear power plant
1100: Reactor coolant system decompression system
1110: Presser
1120: Passive residual heat removal system
1130: Pressure reducing equipment
3. Third Embodiment (Figs. 5 to 6)
The same reference numerals as those in Figs. 1 to 2 are given as follows.
120: Nuclear power plant
1200: Reactor coolant system decompression system
1210: Presser
1220: Passive residual heat removal system
1230: Pressure reducing equipment
4. Fourth Embodiment (Figs. 7 to 8)
The same reference numerals as those in Figs. 1 to 2 are given as follows.
130: Nuclear power plant
1300: Reactor coolant system decompression system
1310: Presser
1320: Passive residual heat removal system
1330: Pressure reducing equipment
5. Fifth Embodiment (Figs. 9 to 10)
The same reference numerals as those in Figs. 1 to 2 are given as follows.
140: Nuclear power plant
1400: Reactor coolant system decompression system
1410: Presser
1420: Passive residual heat removal system
1430: Pressure reducing equipment
6. Sixth Embodiment (Figs. 11 to 12)
The same reference numerals as those in Figs. 1 to 2 are given as follows.
150: Nuclear power plant
1500: Reactor coolant system decompression system
1510: Presser
1520: Passive residual heat removal system
1530: Pressure reducing equipment
7. Seventh Embodiment (Figs. 13 to 14)
The same reference numerals as those in Figs. 1 to 2 are given as follows.
160: Nuclear power plant
1600: Reactor coolant system decompression system
1610: Presser
1620: Passive residual heat removal system
1630: Pressure reducing equipment
8. Eighth Embodiment (Figs. 15 to 16)
The same reference numerals as those in Figs. 1 to 2 are given as follows.
170: Nuclear power plant
1700: Reactor coolant system decompression system
1710: Presser
1720: Passive residual heat removal system
1730: Pressure reducing equipment
9. Ninth embodiment (Figs. 17 to 18)
The same reference numerals as those in Figs. 1 to 2 are given as follows.
180: Nuclear power plant
1800: Reactor coolant system decompression system
1810: Pressurizer
1820: Passive residual heat removal system
1830: Pressure reducing equipment
10. Tenth Embodiment (Figs. 19 to 20)
The same reference numerals as those in Figs. 1 to 2 are given as follows.
190: Nuclear power plant
1900: Reactor coolant system decompression system
1910: Pressurizer
1920: Passive Residual Removal System
1930: Pressure reducing equipment

Claims (21)

A pressurizer that maintains the pressurized state of the reactor coolant system;
A condensation heat exchanger for removing the sensible heat of the reactor coolant system and the residual heat of the core through heat exchange between fluids; And
And a decompression facility for preventing an overpressure of the reactor coolant system using the condensation heat exchanger when a design basis excess accident in which the function of the passive residual heat elimination system is lost occurs,
The reduced-
A pressure reducing pipe connected to the pressurizer and the condensation heat exchanger to supply steam discharged from the pressurizer to the condensation heat exchanger;
An injection pipe connected to the condensation heat exchanger and the reactor coolant system to inject condensate formed in the condensation heat exchanger into the reactor coolant system; And
And a pressure reducing valve installed in the pressure reducing pipe or the injection pipe,
Wherein the pressure reducing valve is opened to lower the pressure of the reactor coolant system when a design standard excess accident that the function of the passive residual heat eliminating system is lost occurs,
Wherein at least a part of the area of the pressure reducing pipe or at least a part of the area of the injection pipe is composed of a plurality of sections,
Wherein the pressure reducing valve is installed at least one for each of the plurality of branches. The method according to claim 1,
The reduced-
A pressurizer safety pipe connected to the pressurizer and the reactor drainage tank; And
And a pressurizer safety valve installed in the pressurizer safety pipe, the pressurizer safety valve being opened and closed based on a predetermined pressure to suppress an abrupt pressure rise of the reactor coolant system. delete delete A pressurizer that maintains the pressurized state of the reactor coolant system;
A condensation heat exchanger for removing the sensible heat of the reactor coolant system and the residual heat of the core through heat exchange between fluids; And
And a decompression facility for preventing an overpressure of the reactor coolant system using the condensation heat exchanger when a design basis excess accident in which the function of the passive residual heat elimination system is lost occurs,
The reduced-
A pressure reducing pipe connected to the pressurizer and the condensation heat exchanger to supply steam discharged from the pressurizer to the condensation heat exchanger;
An injection pipe connected to the condensation heat exchanger and the reactor coolant system to inject condensate formed in the condensation heat exchanger into the reactor coolant system; And
And a pilot-operated safety discharge valve provided in the pressure reducing pipe,
The pilot operated safety release valve includes:
A first valve configured to suppress an abrupt pressure rise of the reactor coolant system; And
And a second valve operable to lower the pressure of the reactor coolant system when the function of the driven residual heat elimination system is lost due to occurrence of an accident exceeding a design standard. 6. The method of claim 5,
Wherein at least a partial area of the pressure reducing pipe is composed of a plurality of forkings,
And the pilot-operated safe discharge valve is installed for each of the plurality of branches. The method according to claim 1,
Wherein the depressurization facility further includes a condensed water accommodating portion installed in the injection pipe to store condensed water discharged from the condensation heat exchanger,
Wherein the condensed water accommodating portion is configured to inject condensed water stored in the reactor coolant system into the reactor coolant system when pressure equilibrium is established with the reactor coolant system. A pressurizer that maintains the pressurized state of the reactor coolant system;
A condensation heat exchanger for removing the sensible heat of the reactor coolant system and the residual heat of the core through heat exchange between fluids; And
And a decompression facility for preventing an overpressure of the reactor coolant system using the condensation heat exchanger when a design basis excess accident in which the function of the passive residual heat elimination system is lost occurs,
The reduced-
A pressure reducing pipe connected to the pressurizer and the condensation heat exchanger to supply steam discharged from the pressurizer to the condensation heat exchanger;
An injection pipe connected to the condensation heat exchanger and the reactor coolant system to inject condensate formed in the condensation heat exchanger into the reactor coolant system; And
And a condensed water accommodating portion installed in the injection pipe to store condensed water discharged from the condensation heat exchanger,
Wherein the condensed water accommodating portion is configured to inject condensed water stored therein into the reactor coolant system when pressure equilibrium is established with the reactor coolant system,
Wherein the decompression facility further comprises a rupture plate installed at least one of the decompression pipe, the injection pipe, and the condensed water container,
Wherein the rupture plate ruptures when the pressure of the decompression facility rises above a predetermined reference. 9. The method according to claim 7 or 8,
Wherein the decompression facility further comprises an atmospheric release isolation valve installed at least one of the decompression pipe, the injection pipe, and the condensed water accommodating portion,
Wherein the atmospheric release isolation valve is opened when the pressure of the decompression facility rises above a preset reference. A pressurizer that maintains the pressurized state of the reactor coolant system;
A condensation heat exchanger for removing the sensible heat of the reactor coolant system and the residual heat of the core through heat exchange between fluids; And
And a decompression facility for preventing an overpressure of the reactor coolant system using the condensation heat exchanger when a design basis excess accident in which the function of the passive residual heat elimination system is lost occurs,
The reduced-
A pressure reducing pipe connected to the pressurizer and the condensation heat exchanger to supply steam discharged from the pressurizer to the condensation heat exchanger;
An injection pipe connected to the condensation heat exchanger and the reactor coolant system to inject condensate formed in the condensation heat exchanger into the reactor coolant system; And
And a condensed water accommodating portion installed in the injection pipe to store condensed water discharged from the condensation heat exchanger,
Wherein the condensed water accommodating portion is configured to inject condensed water stored therein into the reactor coolant system when pressure equilibrium is established with the reactor coolant system,
Wherein the depressurization facility includes a non-condensable gas exhaust line configured to remove non-condensable gas flowing through the injection line,
Wherein the non-condensable gas discharge pipe is connected to a lower portion of the condensation heat exchanger, an upper portion of the condensed water storage portion, or the injection pipe. A pressurizer that maintains the pressurized state of the reactor coolant system;
A condensation heat exchanger for removing the sensible heat of the reactor coolant system and the residual heat of the core through heat exchange between fluids; And
And a decompression facility for preventing an overpressure of the reactor coolant system using the condensation heat exchanger when a design basis excess accident in which the function of the passive residual heat elimination system is lost occurs,
The reduced-
A pressure reducing pipe connected to the pressurizer and the condensation heat exchanger to supply steam discharged from the pressurizer to the condensation heat exchanger; And
And an injection pipe connected to the condensation heat exchanger and the reactor coolant system to inject condensate formed in the condensation heat exchanger into the reactor coolant system,
Wherein the driven residual heat removing system includes an emergency cooling water storage portion formed to store cooling water,
Wherein the emergency cooling water storage unit has an opening for discharging steam formed by evaporation of the cooling water. 12. The method of claim 11,
Wherein the emergency cooling water storage portion is provided outside the storage portion,
The condensing heat exchanger is installed inside the compartment,
Wherein the emergency cooling water storage unit and the condensation heat exchanger are connected to each other by first and second circulation pipes for circulation of the cooling water. 12. The method of claim 11,
Wherein the emergency cooling water storage portion is provided outside the storage portion,
And the condensation heat exchanger is installed inside the emergency cooling water storage part. 12. The method of claim 11,
The emergency cooling water storage unit is installed inside the compartment,
And the condensation heat exchanger is installed inside the emergency cooling water storage part. A pressurizer that maintains the pressurized state of the reactor coolant system;
A condensation heat exchanger for removing the sensible heat of the reactor coolant system and the residual heat of the core through heat exchange between fluids; And
And a decompression facility for preventing an overpressure of the reactor coolant system using the condensation heat exchanger when a design basis excess accident in which the function of the passive residual heat elimination system is lost occurs,
The reduced-
A pressure reducing pipe connected to the pressurizer and the condensation heat exchanger to supply steam discharged from the pressurizer to the condensation heat exchanger; And
And an injection pipe connected to the condensation heat exchanger and the reactor coolant system to inject condensate formed in the condensation heat exchanger into the reactor coolant system,
The passive residual heat removal system is connected to the reactor coolant system to circulate a primary fluid,
Wherein the pressure reducing pipe forms a flow path for supplying steam to the condensing heat exchanger for operation of the driven residual heat eliminating system and operation of the pressure reducing equipment,
Wherein the passive residual heat elimination system includes a water supply pipe bypassing the injection pipe and connected to the condensation heat exchanger and the reactor coolant system. 16. The method of claim 15,
Wherein the driven residual heat elimination system includes an isolation valve installed in the water supply pipe,
Wherein the isolation valve is opened during operation of the driven residual heat removal system and closed during operation of the reduced-pressure facility. A pressurizer that maintains the pressurized state of the reactor coolant system;
A condensation heat exchanger for removing the sensible heat of the reactor coolant system and the residual heat of the core through heat exchange between fluids; And
And a decompression facility for preventing an overpressure of the reactor coolant system using the condensation heat exchanger when a design basis excess accident in which the function of the passive residual heat elimination system is lost occurs,
The reduced-
A pressure reducing pipe connected to the pressurizer and the condensation heat exchanger to supply steam discharged from the pressurizer to the condensation heat exchanger; And
And an injection pipe connected to the condensation heat exchanger and the reactor coolant system to inject condensate formed in the condensation heat exchanger into the reactor coolant system,
The passive residual heat removing system is connected to a steam generator installed at the boundary between the primary system and the secondary system to circulate the secondary fluid,
The driven residual heat elimination system includes:
A steam pipe branched from the main steam pipe connected to the steam generator and the turbine system and connected to the condensing heat exchanger; And
And a water supply pipe branched from the main water supply pipe connected to the steam generator and the water supply system and connected to the condensation heat exchanger. 18. The method of claim 17,
Wherein the passive residual heat eliminating system includes the steam pipe and the isolation valves installed in the water supply pipe,
Wherein the isolation valves are opened during operation of the driven residual heat removal system and closed during operation of the reduced-pressure facility. A pressurizer that maintains the pressurized state of the reactor coolant system;
A condensation heat exchanger for removing the sensible heat of the reactor coolant system and the residual heat of the core through heat exchange between fluids; And
And a decompression facility for preventing an overpressure of the reactor coolant system using the condensation heat exchanger when a design basis excess accident in which the function of the passive residual heat elimination system is lost occurs,
The reduced-
A pressure reducing pipe connected to the pressurizer and the condensation heat exchanger to supply steam discharged from the pressurizer to the condensation heat exchanger;
An injection pipe connected to the condensation heat exchanger and the reactor coolant system to inject condensate formed in the condensation heat exchanger into the reactor coolant system;
An automatic decompression piping branched from the decompression piping and connected to the reactor building internal storage tank; And
And an automatic pressure reducing valve installed in the automatic pressure reducing pipe and opened when the pressure of the reactor coolant system reaches a predetermined operating value. Reactor coolant system;
A compartment formed to enclose the reactor coolant system; And
And a reactor coolant system pressure reducing system for preventing overpressure of the reactor coolant system,
The reactor coolant system decompression system comprises:
A pressurizer that maintains the pressurized state of the reactor coolant system;
A condensation heat exchanger for removing the sensible heat of the reactor coolant system and the residual heat of the core through heat exchange between fluids; And
And a decompression facility for preventing overpressure of the reactor coolant system using the condensation heat exchanger when the passive residual heat elimination system is inoperable,
The reduced-
A decompression pipe connected to the reactor coolant system and the condensation heat exchanger to supply steam discharged from the reactor coolant system to the condensation heat exchanger;
An injection pipe connected to the condensation heat exchanger and the reactor coolant system to inject condensate formed in the condensation heat exchanger into the reactor coolant system; And
And a pressure reducing valve installed in the pressure reducing pipe or the injection pipe,
Wherein the pressure reducing valve is opened to lower the pressure of the reactor coolant system when a design standard excess accident that the function of the passive residual heat eliminating system is lost occurs,
Wherein at least a part of the area of the pressure reducing pipe or at least a part of the area of the injection pipe is composed of a plurality of sections,
Wherein at least one pressure reducing valve is provided for each of the plurality of branches. 21. The method of claim 20,
Wherein the nuclear reactor comprises a safety injection system configured to inject a coolant into the reactor coolant system,
The safety infusion system comprising a safety infusion conduit connected to the reactor coolant system to form an infusion passage for the coolant,
Wherein the injection piping is connected to the safety injection piping.

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