Small nuclear reactor cooling device and cooling method

Abstract

A small-scale nuclear reactor cooling device and a cooling method are provided. The small-scale nuclear reactor cooling device includes a reactor vessel in which cooling water circulates along a flow path structure, and a cooling water storage unit that is provided inside the reactor vessel and is filled with the cooling water based on the circulating flow, and when a molten core occurs in the reactor vessel due to the occurrence of a serious accident, the cooling water storage unit comes into contact with the molten core via the cooling water filled inside to cool the molten core and prevent the molten core from leaking out to the outside.

Description

[Technical Field]

[0001] The present invention relates to a small nuclear reactor cooling system and method. [Background technology]

[0002] In the field of nuclear power plant-related technology, small modular reactors (SMRs) have been developed with an emphasis on improving safety. However, despite the existence of various related safety shutdown systems, there have been no specific developments of measures to prevent the external leakage of molten material from the reactor core of an SMR in the event of a severe accident, which has an extremely low probability of occurring.

[0003] In the event of a severe accident at a typical large-scale commercial nuclear power plant, various countermeasures are taken to contain and cool the molten core so that it does not react directly with the concrete floor of the cavity below the reactor building in order to deal with the loss of integrity of the reactor building. For example, a typical facility is the Core Catcher, which collects, holds, and cools the molten core in the cavity below the reactor building by supplying cooling water.

[0004] This core catcher was developed by installing a cooling channel below the conventional core melt collection vessel to cool the molten core. This technology has been applied to Areva's EPR and GE's ESBWR. Areva's EPR core catcher consists of a pre-catcher that collects the molten core, a core melt transfer channel, and a space for spreading and cooling the molten core. Areva's EPR's cooling channel is horizontal and has a square cooling channel shape that is separated by a structure that holds the molten core and supports the diffusion vessel.

[0005] GE's ESBWR core catcher is a funnel-shaped container installed directly below the reactor to collect, spread, and cool the molten core. All of these existing core catchers are installed outside the reactor. However, in the case of SMRs, which do not have a containment building or are designed to be almost in close contact with the reactor vessel, it is not possible to install such a core catcher. Summary of the Invention [Problem to be solved by the invention]

[0006] The problem to be solved by the present invention is to enable in-vessel retention of the internal molten core in the event of a severe accident in an SMR.

[0007] Another purpose is to ensure that in the event of a serious accident, molten core material is caught in the upper part of the cooling water tank below the reactor.

[0008] Another object is to ensure that other passive or active safety measures are used to allow time for the system to be smoothly shut down and cooled.

[0009] The objects of the present invention are not limited to those mentioned above, and other objects not mentioned herein will be clearly understood by those skilled in the art from the following description. [Means for solving the problem]

[0010] To achieve the above object, a small reactor cooling method according to one aspect of the present invention includes the steps of: circulating cooling water inside a reactor vessel along a flow path structure; filling the circulating cooling water into a cooling water storage unit inside the reactor vessel; generating a core melt in the reactor vessel due to the occurrence of a severe accident; and cooling the core melt using the cooling water filled inside the cooling water storage unit to prevent the core melt from leaking out.

[0011] The cooling water storage unit includes a container located under the inner circumferential surface of the reactor vessel, and an injector provided in the container into which the cooling water is injected by the circulating flow.

[0012] The injector allows the cooling water to flow from the outside to the inside, and prevents the cooling water from flowing from the inside to the outside.

[0013] Also, the injection body prevents leakage by a unidirectional opening and closing operation.

[0014] The opening and closing operation of the injection body is performed by a check valve method.

[0015] The container has a lower portion formed to correspond to the lower inner circumferential surface of the reactor vessel, and an upper portion formed to be rounded downward.

[0016] The injector is provided on at least a portion of the upper periphery of the container, based on the downwardly rounded upper portion, and receives the cooling water injected by the circulating flow.

[0017] To achieve the above object, according to another aspect of the present invention, a small-scale reactor cooling device includes a reactor vessel in which cooling water inside circulates along a flow path structure; and a cooling water storage unit that is provided inside the reactor vessel and into which the cooling water is filled based on the circulating flow. When a core melt occurs in the reactor vessel due to the occurrence of a serious accident, the cooling water storage unit comes into contact with the core melt via the cooling water filled inside, thereby cooling the core melt and preventing the core melt from leaking out. [Effects of the Invention]

[0018] The small-scale nuclear reactor cooling system and cooling method of the present invention as described above have one or more of the following advantages.

[0019] The present invention can provide in-vessel retention of the internal molten core in the event of a severe accident in an SMR.

[0020] In addition, in the event of a serious accident, the molten core material can be caught above the cooling water tank below the reactor.

[0021] Additionally, other passive or active safety features may allow time for the system to smoothly shut down and cool down. [Brief explanation of the drawings]

[0022] [Figure 1] 1 is a block diagram showing the configuration of a small nuclear reactor cooling device according to an embodiment of the present invention. [Figure 2] FIG. 2 is a block diagram showing the configuration of FIG. 1 in detail. [Figure 3] FIG. 2 is a diagram showing the configuration according to FIG. 1. [Figure 4] FIG. 2 is a schematic diagram showing an embodiment of the arrangement according to FIG. 1; [Figure 5] 2 is a schematic diagram showing another embodiment of the arrangement according to FIG. 1; [Figure 6] 1 is a flowchart sequentially illustrating a method for cooling a small nuclear reactor according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0023] Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Advantages and features of the present invention will be described in detail below with reference to the accompanying drawings. The advantages and features of the present invention, as well as methods for achieving them, will become clear from the following detailed description of the embodiments in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, and can be embodied in various different forms. The present embodiments are provided merely to complete the disclosure of the present invention and to fully convey the scope of the invention to those skilled in the art to which the present invention pertains, and the present invention is defined solely by the scope of the claims. The same reference symbols refer to the same elements throughout the specification.

[0024] 1, a small reactor cooling system 100 according to an embodiment of the present invention includes a reactor vessel 110, a flow path structure 120, a reactor core 130, and a coolant storage unit 140. Referring to FIG. 2, the coolant storage unit 140 includes a container 141 and an injector 142.

[0025] 2 to 4, the reactor vessel 110 of the small reactor cooling device 100 is provided with the flow path structure 120 therein. The flow path structure 120 is for circulating the cooling water W1 inside the reactor vessel 110.

[0026] The flow path structure 120 corresponds to a predetermined structure or area for circulating the cooling water W1. The cooling water storage unit 140 is provided inside the reactor vessel 110.

[0027] 4, the cooling water storage unit 140 is at least partially filled with the cooling water W1 based on the circulating flow of the cooling water W1. When a meltdown occurs in the reactor vessel 110 due to a severe accident, the cooling water storage unit 140 comes into contact with the meltdown through the cooling water W1 filled therein.

[0028] The cooling water storage unit 140 cools the molten core by contacting with the molten core, and at the same time, prevents the molten core from leaking out.

[0029] Here, the cooling water storage unit 140 serves to collect the molten core and prevent direct heat transfer with the lower outer wall of the reactor vessel 110. The container 141 of the cooling water storage unit 140 is located below the inner circumferential surface of the reactor vessel 110.

[0030] The inlet 142 of the cooling water storage unit 140 is provided in the container 141. The inlet 142 receives the cooling water W1 through the circulating flow of the cooling water.

[0031] Furthermore, the injector 142 allows the cooling water W1 to flow from the outside to the inside, and prevents the cooling water W1 from flowing from the inside to the outside.

[0032] The injection body 142 prevents the outflow by a unidirectional opening and closing operation, and the opening and closing operation of the injection body 142 is performed by a check valve or the like.

[0033] The container 141 has a lower portion 1412 that corresponds to the lower inner circumferential surface of the reactor vessel 110. The container 141 has an upper portion 1411 that is rounded downward.

[0034] The injector 142 is provided on at least a portion of the upper periphery of the receiving body 141 based on the downwardly rounded upper part 1411. The cooling water W1 is injected into the injector 142 by the circulating flow of the cooling water W1.

[0035] Here, the container 141 is provided so that a part of the outer periphery has a double structure as shown in Fig. 3. Furthermore, the container 141 may be provided so that the entire outer periphery on the top, bottom, left and right sides has a double structure as shown in Fig. 4.

[0036] 6, in a small-scale nuclear reactor cooling method S100 according to an embodiment of the present invention, cooling water W1 inside a reactor vessel 110 circulates along a flow path structure 120. The circulating cooling water W1 is filled inside a cooling water storage unit 140 inside the reactor vessel 110.

[0037] If a serious accident occurs, a molten core occurs in the reactor vessel 110. The cooling water storage unit 140 cools the molten core using the cooling water W1 filled therein.

[0038] Furthermore, the cooling water storage unit 140 prevents the molten core from leaking out. The container 141 of the cooling water storage unit 140 is located at the bottom of the inner periphery of the reactor vessel 110.

[0039] The inlet 142 of the cooling water storage unit 140 is provided in the container 141, and the cooling water W1 is injected into the inlet 142 by the circulating flow. The inlet 142 allows the cooling water W1 to flow from the outside to the inside, and prevents the cooling water W1 from flowing out from the inside to the outside.

[0040] The injection body 142 prevents leakage by opening and closing in one direction. The opening and closing operation of the injection body 142 is performed by a check valve. The container 141 has a lower part 1412 formed to correspond to the lower inner circumferential surface of the reactor vessel 110, and an upper part 1411 formed to be rounded downward.

[0041] Here, the injector 142 is provided on at least a part of the upper periphery of the receiving body 141 based on the downwardly rounded upper part 1411. The injector 142 receives the cooling water W1 injected by the circulating flow.

[0042] Although the embodiments of the present invention have been described above with reference to the accompanying drawings, those skilled in the art will understand that the present invention can be embodied in other specific forms without changing the technical spirit or essential features of the present invention. Therefore, it should be understood that the above-described embodiment is illustrative in all respects and is not limiting.

Claims

1. A method for cooling a small nuclear reactor, comprising: a step in which the cooling water inside the reactor vessel circulates along the flow path structure; charging the cooling water into a cooling water storage unit within the reactor vessel; A stage in which a severe accident occurs and a core meltdown occurs in the reactor vessel; and The cooling water storage unit cools the molten core using the cooling water filled therein to prevent the molten core from leaking out, The cooling water storage unit includes: a containment body located at a lower portion of the inner circumferential surface of the reactor vessel; an injector provided in the container and into which the cooling water is injected by the circulating flow, The injector is A small-scale nuclear reactor cooling method, wherein the cooling water flows from the outside to the inside, and the cooling water is prevented from flowing from the inside to the outside.

2. 2. The method of cooling a small nuclear reactor according to claim 1, wherein the injector prevents the leakage by a unidirectional opening and closing action.

3. 3. The method for cooling a small nuclear reactor according to claim 2, wherein the injection body is opened and closed by a check valve system.

4. The container is 2. The method for cooling a small nuclear reactor according to claim 1, wherein the lower portion is formed to correspond to the lower inner peripheral surface of the reactor vessel, and the upper portion is formed to be rounded downward.

5. A method for cooling a small nuclear reactor, comprising: a step in which the cooling water inside the reactor vessel circulates along the flow path structure; charging the cooling water into a cooling water storage unit within the reactor vessel; A stage in which a severe accident occurs and a core meltdown occurs in the reactor vessel; and The cooling water storage unit cools the molten core using the cooling water filled therein to prevent the molten core from leaking out, The cooling water storage unit includes: a containment body that contains the cooling water and has a lower portion provided along a lower inner peripheral surface of the reactor vessel and an upper portion facing the lower inner peripheral surface of the reactor vessel with the lower portion in between; an injector provided on at least a portion of the periphery of the upper part of the containment body, and causing the cooling water injected by the circulating flow to flow into the containment body.

6. A small nuclear reactor cooling device, comprising: A reactor vessel in which cooling water circulates along a flow path structure; a cooling water storage unit provided inside the reactor vessel and filled with the cooling water based on the circulating flow; The cooling water storage unit includes: If a serious accident occurs and a molten core occurs in the reactor vessel, the cooling water filled inside contacts the molten core material to perform a cooling process on the molten core material, thereby preventing the molten core material from leaking out; The cooling water storage unit includes: a containment body located at a lower portion of the inner circumferential surface of the reactor vessel; an injector provided in the container and into which the cooling water is injected by the circulating flow, The injector is A small-scale nuclear reactor cooling device in which the cooling water flows from the outside to the inside and the cooling water is prevented from flowing from the inside to the outside.

7. A small nuclear reactor cooling device, A reactor vessel in which cooling water circulates along a flow path structure; a cooling water storage unit provided inside the reactor vessel and filled with the cooling water based on the circulating flow; The cooling water storage unit includes: If a serious accident occurs and a molten core occurs in the reactor vessel, the cooling water filled inside contacts the molten core material to perform a cooling process on the molten core material, thereby preventing the molten core material from leaking out; The cooling water storage unit includes: a containment body that contains the cooling water and has a lower portion provided along a lower inner peripheral surface of the reactor vessel and an upper portion facing the lower inner peripheral surface of the reactor vessel with the lower portion in between; an injector provided on at least a portion of the periphery of the upper part of the containment body, and causing the cooling water injected by the circulating flow to flow into the containment body.

Images