KR20200119703A - system for reducing the release of radioactive material to the atmosphere under severe accident - Google Patents

Abstract

Provided is a system for reducing emission of radioactive materials to the atmosphere in case of a serious accident. According to an embodiment of the present invention, the system for reducing emission of radioactive materials to the atmosphere in case of a serious accident comprises: a steam generator disposed inside a containment building, producing steam by using heat of coolant heated in a reactor, and connected to a turbine via a main steam line; and a desalination water tank connected to the main steam line via a connection line, and containing demineralized water for reducing emission of radioactive substances to the atmosphere by desalting the steam transferred from the steam generator in case of a serious accident. The desalination water tank is disposed inside the containment building.

Description

System for reducing the release of radioactive material to the atmosphere under severe accident}

The present invention relates to a system for reducing the emission of radioactive materials to the atmosphere in the event of a serious accident that can mitigate the emission of radioactive materials to the atmosphere by bypassing the containment building in case of a serious accident of a nuclear power plant.

After the Fukushima nuclear accident, countries around the world are tightening regulations to secure the ability to cope with serious accidents, not only for improved light water reactors but also for nuclear power plants already in operation.

In the event of a serious accident, the most important measure to prevent the release of radioactive materials is to ensure the integrity of the containment building. To this end, various follow-up measures such as mobile diesel power generation, installation of waterproof sluice gates, and installation of filtering exhaust facilities were undertaken for nuclear power plants in operation or under construction after the Fukushima accident. Through this, the safety of nuclear power plants has been greatly improved.

However, in the event of a serious accident such as a Steam Generator Tube Rupture (SGTR) or a loss of coolant at the low pressure boundary (ISLOCA), radioactive materials bypass the containment building and are discharged directly into the atmosphere even if the containment is secured. As such, it remains an important issue in terms of reactor safety.

KR 10-1905724 B1

The present invention has been devised in consideration of the above points, and provides a system for reducing air emissions of radioactive materials in the event of a serious accident that can alleviate the accident in which radioactive materials are released into the atmosphere by bypassing the containment building in case of a serious accident. There is a purpose.

In order to achieve the above object, the present invention is a steam generator disposed inside a containment building and producing steam using heat of a coolant heated in a nuclear reactor and connected to a turbine via a main steam line; And a decontamination water tank connected via the main steam line and the connection line, and including demineralized water for reducing air emission of radioactive substances by decontaminating the steam transferred from the steam generator in the event of a serious accident. The water tank provides a system for reducing air emissions of radioactive materials in the event of a serious accident disposed inside the containment building.

According to the present invention, when a serious accident occurs, a decontamination tank for removing radioactive substances from the steam introduced from the steam generator is disposed inside the containment building, so that even if the decontamination tank is partially damaged due to an instantaneous pressure increase, the leakage of radioactive materials occurs. The discharge to the outside can be fundamentally blocked by the containment building. Through this, the present invention can improve the safety of a nuclear power plant by bypassing the containment building in the event of a serious accident, thereby preventing accidents in which radioactive materials are released.

In addition, the present invention can improve the performance and safety of the decontamination tank by preventing an instantaneous increase in pressure inside the decontamination tank by introducing high-temperature and high-pressure steam into the decontamination tank.

Moreover, the present invention reduces the pressure of the steam supplied to the decontamination tank through the decompression power generation means and generates emergency power, so that even in the event of a serious accident, driving power can be supplied to the electric equipment that uses electricity. It is possible to check the status and improve the stability of the nuclear power plant.

1 is a schematic diagram showing a system for reducing air emissions of radioactive materials in the event of a serious accident according to an embodiment of the present invention.
2 is a schematic diagram showing a system for reducing air emissions of radioactive materials when a serious accident occurs according to another embodiment of the present invention.
3 is a view showing a detailed configuration of a decontamination tank that can be applied to the system for reducing air emission of radioactive materials in case of a serious accident according to the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those of ordinary skill in the art can easily implement the present invention. The present invention may be implemented in various different forms, and is not limited to the embodiments described herein. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and the same reference numerals are added to the same or similar components throughout the specification.

The systems 100 and 200 for reducing air emission of radioactive materials in the event of a serious accident according to an embodiment of the present invention include a steam generator 110 and a decontamination tank 120 as shown in FIGS. 1 and 2.

The steam generator 110 may be disposed inside the containment building 101, and after generating steam for nuclear power generation, it may be supplied to a turbine (not shown). That is, the steam generator 110 may be connected to the turbine via the main steam line 151 so as to supply the steam to the turbine side.

At this time, at least one valve may be provided on the main steam line 151 to perform various functions such as allowing, blocking, and discharging the flow of steam.

As an example, the at least one valve is a main steam safety valve (MSSV) 161 for preventing excessive pressure in the main steam line 151, and steam when the main steam line 151 is damaged. In order to prevent excessive cooling of the reactor coolant system due to discharge, a main steam isolation valve (MSIV) 163 for isolating the steam generator 110 may be included.

In addition, the at least one valve is an atmospheric release valve 162 for cooling the coolant system of the reactor by directly discharging excess steam to the atmosphere when the steam generator 110 is isolated or when the turbine is stopped or the function of the condenser is lost. (atmospheric dump valve: ADV) may be further included. However, the types and numbers of the valves are not limited thereto and may be appropriately changed according to design conditions.

In this way, the steam generated from the steam generator 110 may be collected in one main steam cavity pipe in the turbine building through at least one valve and then supplied to the turbine.

Here, the main steam safety valve 161 may be automatically opened when the steam pressure reaches a set value, and the atmospheric release valve 162 may be manually operated in a main control room or a remote stop panel.

In addition, inside the containment building 101, a reactor 140 that heats a coolant and supplies the heated coolant to the steam generator 110, and generates steam using the heat of the coolant supplied from the reactor 140. A steam generator 110 or the like may be disposed, and a nuclear fuel reloading tank 105 for supplying nuclear fuel to the reactor 140 may be configured. Since the internal structure of the containment building 101 is known, detailed description will be omitted.

The decontamination water tank 120 may decontaminate the steam transferred from the steam generator 110 in the event of a serious accident such as the breakage of the custom tube 112 of the steam generator 110. Through this, when a serious accident occurs, the amount of radioactive material directly discharged to the atmosphere may be reduced by removing the radioactive material from the steam generated from the steam generator 110 through decontamination.

To this end, the desalination water tank 120 may be filled with demineralized water 121 for desalting the steam, and may be connected to the main steam line 151 and the connection line 152 as a medium.

As an example, the connection line 152 may have one end connected to the decontamination tank 120 and the other end connected to an air emission reduction valve 165 installed on the main steam line 151, and the air emission reduction The valve 165 may be provided as a three-way valve.

Accordingly, during normal operation, the high-pressure steam generated by the steam generator 110 is supplied to the turbine side along the main steam line 151 to generate power, and in case of a design-based accident, the steam generator 110 generates power. High-pressure steam may be discharged to the atmosphere through the atmospheric release valve 162, and in the event of a serious accident, the high-pressure steam generated by the steam generator 110 is transferred to the desalination tank 120 through the connection line 152. ) Can be transferred.

Accordingly, when a serious accident occurs, radioactive materials contained in the high-temperature steam are decontaminated through the decontamination water 121 in the decontamination water tank 120, thereby reducing the emission of radioactive materials contained in the high-temperature steam to the atmosphere.

Here, the serious accident may be a bypass accident of the containment building 101, such as a steam generator tube rupture (SGTR) of the steam generator tube 112 or a loss of coolant at the low pressure boundary (ISLOCA).

At this time, the system 100 and 200 for reducing air emissions of radioactive materials in the event of a serious accident according to an embodiment of the present invention, as shown in FIG. 3, the connection line 152 is at the lower side of the desalination tank 120 It may be connected, and at least one nozzle 122 may be provided at an end of the connection line 152.

Here, the nozzle 122 may be disposed at a lower end of the desalination tank 120. Through this, the nozzle 122 can always be kept submerged in the decontamination water 121 filled in the decontamination water tank 120.

In addition, the desalination water tank 120 may include an outlet, and the outlet may be provided on the upper side of the desalination water tank 120. Accordingly, the vapor that is not dissolved in the demineralized water 121 after being transferred to the desalination water tank 120 may be discharged to the outside through the outlet.

In this case, the vapor not dissolved in the demineralized water 121 may contain radioactive materials. Accordingly, if the steam not dissolved in the demineralized water 121 is directly discharged to the outside through the outlet of the demineralized water 121, the radioactive material contained in the steam not dissolved in the demineralized water 121 is discharged to the outside. Can be.

In order to prevent this, the system (100, 200) for reducing the emission of radioactive materials to the atmosphere in the event of a serious accident according to an embodiment of the present invention includes the desalination tank 120 through a bypass line 153 as a medium to the filter and exhaust device 130. Can be connected with. Through this, the vapor that has passed through the decontamination tank 120 is not directly discharged to the atmosphere through the outlet, but may be discharged to the outside after passing through the filter and exhaust device 130.

Here, the bypass line 153 may be connected through a nuclear fuel reloading tank 105 and a discharge line 154 provided inside the containment building 101, and a valve 164 at the side of the bypass line 153 May be provided.

As a non-limiting example, the valve 164 may be a three-way valve. Accordingly, the steam discharged from the decontamination tank 120 may move toward the filter and exhaust system 130 or the nuclear fuel reload tank 105 in the containment building 101 through the adjustment of the three-way valve.

Through this, the vapor discharged from the decontamination tank 120 may be further decontaminated with radioactive materials through the filter and exhaust device 130 or the nuclear fuel reloading tank 105.

In the present invention, the decontamination tank 120 may be disposed inside the containment building 101 as shown in FIGS. 1 and 2.

In such a case, when a serious accident occurs, the desalination tank 120 is placed inside the containment building 101 to remove the radioactive material of the steam introduced from the steam generator 110, so that the desalination tank 120 momentarily increases the pressure. Even if the radioactive material is partially damaged and leaks out from the decontamination tank 120, the radioactive material leaked from the decontamination tank 120 may be discharged into the containment building 101.

Through this, the radioactive material discharged from the decontamination tank 120 can be moored inside the containment building 101, so that discharge to the outside atmosphere can be fundamentally blocked. Accordingly, the system 100 and 200 for reducing air emissions of radioactive materials in case of a serious accident according to an embodiment of the present invention bypasses the containment building 101 in the event of a serious accident and prevents accidents in which radioactive materials are released to the outside. By being able to do so, the safety of nuclear power plants can be further improved.

In this case, the systems 100 and 200 for reducing air emission of radioactive materials in the event of a serious accident according to an embodiment of the present invention may further include a cooling means 124. Such cooling means 124 may be arranged to surround the outside of the decontamination water tank 120 as shown in FIG. 3. Accordingly, the cooling means 124 may cool the desalination water tank 120.

That is, the cooling means 124 may sufficiently condense the steam introduced into the desalination water tank 120 by reducing the pressure and temperature in the desalination water tank 120 through cooling. Through this, it is possible to prevent the risk of damage to the decontamination tank due to dynamic load.

Here, the cooling means 124 may be installed outside the desalination tank 120 and may be in the form of a water tank. In addition, the cooling means 124 may include at least one cooling fin to improve external cooling performance, and fire water or the like may be filled therein.

Meanwhile, the system 200 for reducing air emission of radioactive materials in the event of a serious accident according to an embodiment of the present invention may further include decompression power generation means 170 and 180 as shown in FIG. 2.

The decompression power generation means 170 and 180 may generate emergency power while lowering the pressure of the steam transferred from the steam generator 110 to the desalination tank 120 when a serious accident occurs.

To this end, the pressure-reducing power generation means 170 and 180 may be disposed on a connection line 152 connecting the main steam line 151 and the decontamination tank 120 as shown in FIG. 2.

Through this, the high-pressure steam generated from the steam generator 110 can pass through the decompression power generation means 170 and 180 through the main steam line 151 and the connection line 152 and then move to the desalination tank 120. have.

As an example, the decompression generating means (170, 180) includes a turbine 170 including a plurality of blades rotating through the high-pressure steam transferred from the steam generator 110, and emergency power through the rotation of the turbine 170 It may include a generator 180 to produce.

Accordingly, the high-pressure steam transferred from the steam generator 110 can be decompressed in the process of passing through the turbine 170, and the high-pressure steam transferred from the steam generator 110 is decontaminated in a reduced pressure state. It may be transferred to the water tank 120 side.

Accordingly, since the supply of instantaneous high-pressure steam from the steam generator 110 to the decontamination tank 120 is blocked, the risk of damage to the desalination tank 120 by the high-pressure steam can be significantly reduced. .

That is, the high-pressure steam supplied from the steam generator 110 to the decompression power generation means 170 and 180 is depressurized in the process of passing through the decompression power generation means 170 and 180 to reduce the momentum, and the steam in a state of reduced momentum By being supplied to the desalination water tank 120 side, it is possible to prevent damage of the desalination water tank 120 due to high-pressure steam.

Through this, the system 200 for reducing air emission of radioactive materials in the event of a serious accident according to an embodiment of the present invention can increase the stability of the decontamination tank 120.

In addition, in the system 200 for reducing air emission of radioactive materials in the event of a serious accident according to an embodiment of the present invention, since the decontamination tank 120 is disposed inside the containment building 101, decontamination by high-pressure steam Even if some damage of the water tank 120 occurs, radioactive materials discharged from the decontamination tank 120 may be blocked from being discharged to the outside by the containment building 101, thereby fundamentally blocking the shed from which radioactive materials are discharged. have.

In addition, the system 200 for reducing the emission of radioactive materials to the atmosphere in the event of a serious accident according to an embodiment of the present invention uses the high-pressure steam transferred from the steam generator 110 in the emergency power generation means (170, 180). It can produce electricity.

Accordingly, the system 200 for reducing the emission of radioactive materials to the atmosphere in the event of a serious accident according to an embodiment of the present invention is emergency power generated by the decompression power generation means 170 and 180 even if the power supplied from the outside is cut off when a serious accident occurs. It is possible to monitor the state of the interior of the containment building 101 by using.

To this end, the system 200 for reducing air emission of radioactive materials in the event of a serious accident according to an embodiment of the present invention is provided in the containment building 101 to detect the internal state of the containment building 101. At least one sensor 190 may be included, and the at least one sensor 190 may use emergency power generated through the decompression power generation means 170 and 180 as driving power.

Here, the at least one sensor 190 may be applied to various known sensors such as a temperature sensor, a water level sensor, and a pressure sensor for detecting a state inside the containment building.

Accordingly, the system 200 for reducing air emissions of radioactive materials in the event of a serious accident according to an embodiment of the present invention is the reduced pressure power generation means even if the supply of power is stopped due to the occurrence of a serious accident inside the containment building 101. Various electric devices installed in the containment building 101 can be driven by using the emergency power produced through (170, 180). For this reason, the system 200 for reducing air emission of radioactive materials in the event of a serious accident according to an embodiment of the present invention can quickly grasp the initial state of the occurrence of the serious accident and can quickly perform an appropriate response.

The decompression power generation means 170 and 180 may be installed inside the containment building 101 like the decontamination tank 120 as shown in FIG. 2.

In this case, the connection line 152 connecting the main steam line 151 and the desalination tank 120 has one end connected to the decontamination tank 120 and the other end installed on the main steam line 151 to reduce air emissions. While being connected to the valve 165 may be disposed to be located inside the containment building 101, the pressure-reducing power generation means 170 and 180 may be installed in the connection line 152.

Through this, it is possible to facilitate wiring of a cable (not shown) for providing the electric power generated from the decompression power generation means 170 and 180 to the at least one sensor 190.

Although an embodiment of the present invention has been described above, the spirit of the present invention is not limited to the embodiment presented in the present specification, and those skilled in the art who understand the spirit of the present invention can add components within the scope of the same idea. Other embodiments may be easily proposed by changing, deleting, adding, etc., but it will be said that this is also within the scope of the present invention.

100,200: A system for reducing the emission of radioactive materials to the atmosphere in the event of a serious accident
101: containment building 105: nuclear fuel reload tank
110: steam generator 112: customs
120: desalting water tank 121: desalting water
122: nozzle 124: cooling means
130: filtering and exhaust device 140: nuclear reactor
151: main steam line 152: connection line
153: bypass line 154: discharge line
161: main steam safety valve 162: atmosphere release valve
163: main steam isolation valve 164: valve
165: valve for reducing air emission 170: turbine
180: generator 190: sensor

Claims (10)

A steam generator disposed inside the containment building, producing steam using heat of the coolant heated in the reactor, and connected to the turbine via the main steam line; And
Including; a desalination water tank connected via the main steam line and the connection line and containing demineralized water for reducing air emission of radioactive substances by decontaminating the steam transferred from the steam generator when a serious accident occurs, and
The decontamination tank is a system for reducing air emissions of radioactive materials in the event of a serious accident disposed inside the containment building. The method of claim 1,
In the event of a serious accident, the system for reducing the emission of radioactive substances to the atmosphere further comprises: a decompression power generation means for generating emergency power while lowering the pressure of the steam transferred from the steam generator to the decontamination tank when a serious accident occurs. A system for reducing the emission of radioactive materials to the atmosphere. The method of claim 2,
The decompression power generation means includes a turbine including a plurality of blades rotating through the steam transferred from the steam generator, and a generator that generates power through rotation of the turbine, for reducing the emission of radioactive materials to the atmosphere in the event of a serious accident. system. The method of claim 2,
The reduced-pressure power generation means is a system for reducing air emissions of radioactive materials when a serious accident occurs, which is disposed on the connection line so as to be located inside the containment building. The method of claim 2,
The system for reducing the emission of radioactive materials to the atmosphere when the serious accident occurs,
A system for reducing air emission of radioactive materials in the event of a serious accident, wherein at least one sensor for checking the internal state of the containment building is disposed inside the containment building when a serious accident occurs. The method of claim 5,
The at least one sensor is a system for reducing the emission of radioactive materials to the atmosphere in the event of a serious accident driven by emergency power produced through the decompression power generation means. The method of claim 1,
The serious accident is a system for reducing the emission of radioactive materials to the atmosphere in the event of a serious accident, which is a breakage of a customs pipe of a steam generator or a loss of coolant at a low pressure boundary. The method of claim 1,
The decontamination water tank includes at least one nozzle provided at an end of the connection line. A system for reducing air emission of radioactive materials in the event of a serious accident. The method of claim 1,
The system for reducing the emission of radioactive materials to the atmosphere in the event of a serious accident, the system for reducing the emission of radioactive materials to the atmosphere in the event of a serious accident, further comprising a filter and exhaust device connected through an outlet of the decontamination tank and a bypass line. The method of claim 1,
The system for reducing air emission of radioactive substances in the event of a serious accident, a cooling means arranged to surround the outside of the decontamination water tank to cool the desalination water tank; a system for reducing air emission of radioactive materials in the event of a serious accident .

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