Passive cooling system of small modular reactor

Abstract

The present invention relates to a passive cooling system of a small modular reactor, and to the passive cooling system of the small modular reactor, the system comprising: a reactor building having an inner space; an integral reactor which is located in the reactor building and which includes a reactor core and a steam generator; a containment vessel, which is located in the reactor building, accommodates the integral reactor and has a cooling space encompassing the integral reactor; a first heat exchanger which is formed in the cooling space, and which cools and condenses the steam discharged from the integral reactor; and a passive cooling unit, which condenses, by means of passive heat exchange, the steam discharged from the steam generator, re-supplies the condensed steam to the steam generator, and passively removes the heat generated in the first heat exchanger.

Description

Passive cooling system of a small modular reactor

[0001] The present invention relates to a passive cooling system for a small modular nuclear reactor.

[0002] Unlike conventional reactors, the conventional small modular reactor is designed in such a way that the steam generator and reactor core are integrated into a single vessel.

[0003] Here, existing small modular reactors and containment cooling systems face the problem of corrosion of the containment vessel's outer wall, as the containment vessel is operated partially or fully submerged in water. Furthermore, instruments and devices located outside the containment vessel for normal operation must be designed to maintain their original functions even when permanently submerged, making maintenance difficult.

[0004] An object of the present invention is to provide a passive cooling system for a small modular reactor.

[0005] The present invention relates to a passive cooling system for a small modular reactor, comprising: a reactor building forming an internal space; an integral reactor located within the reactor building and including a core and a steam generator; a containment vessel located within the reactor building and having a cooling space surrounding the integral reactor and accommodating the integral reactor; a first heat exchanger formed within the cooling space and cooling and condensing steam discharged from the integral reactor; and a passive cooling unit that condenses steam discharged from the steam generator through passive heat exchange and resupplies the condensed steam to the steam generator, and passively removes heat generated in the first heat exchanger.

[0006] The above first heat exchanger is located above the integral reactor, and the outer surface of the containment vessel can be in contact with the atmosphere of the internal space.

[0007] The above passive cooling unit may include a cooling water tank containing cooling water; a second heat exchanger positioned within the cooling water; an air flow structure positioned above the cooling water tank and forming an air flow space; a first circulation unit connecting the steam generator and the second heat exchanger; and a second circulation unit connecting the first heat exchanger and the cooling water cooler.

[0008] A first communication port may be formed on the upper wall surface of the above cooling water tank, and a second communication port may be formed on the wall surface of the above air flow structure to connect the above air flow space with the outside atmosphere.

[0009] The above passive cooling unit may further include a moisture separation unit that is at least partially connected to the first communication port and separates moisture from steam discharged into the airflow space through the first communication port.

[0010] The above first circulation section may be formed as a closed loop in which the steam generator and the second heat exchanger are connected to each other.

[0011] The second circulation unit may include a first discharge pipe for delivering heated cooling water inside the first heat exchanger to the cooling water tank; and a first supply pipe for delivering the cooling water from the cooling water tank to the first heat exchanger.

[0012] The above passive cooling unit may further include a partition wall that divides the cooling water into a first zone and a second zone, the second heat exchanger may be located in the first zone, and the second circulation unit may be connected to the second zone.

[0013] A third communication port may be formed in the above bulkhead to enable the flow of cooling water between the first zone and the second zone.

[0014] A first air vent is formed on the upper wall of the reactor building, and external air can be introduced into the internal space through the first air vent.

[0015] The container may further include a support structure supporting the container, and at least a portion of the support structure may have a second air communication section formed therein to allow the flow of external air introduced into the internal space.

[0016] According to the present invention, a passive cooling system for a small modular reactor is provided.

[0017] FIG. 1 is a diagram of a passive cooling system of a small modular reactor according to an embodiment of the present invention.

[0018] FIG. 2 is a passive cooling system of a small modular reactor according to another embodiment of the present invention.

[0019] Figure 3 illustrates a support structure that supports the containment vessel.

[0020] The present invention will be described in more detail with reference to the drawings below.

[0021] The attached drawings are merely examples intended to more specifically illustrate the technical concepts of the present invention, and therefore, the scope of the present invention is not limited to the attached drawings. Furthermore, the attached drawings may exaggerate the size and spacing of components to illustrate the relationships between components.

[0022] Hereinafter, the “small modular reactor” or “integrated reactor” in the present invention is also called a small modular reactor, and refers to a reactor in which a steam generator and a pressurizer are arranged within the reactor.

[0023] A passive cooling system (hereinafter referred to as “cooling system”) of a small modular reactor according to one embodiment and another embodiment of the present invention is described through FIGS. 1 and 2.

[0024] FIG. 1 is a diagram of a passive cooling system of a small modular reactor according to an embodiment of the present invention.

[0025] The cooling system (10) includes a reactor building (100), an integral reactor (200), a containment vessel (300), and a passive cooling unit (400).

[0026] The reactor building (100) forms an interior space (T) and can be made of concrete. An integrated reactor (200), a containment vessel (300), a passive cooling unit (400), and a support structure (500) are appropriately arranged within the building.

[0027] A first air passage (110) is formed on the upper wall of the reactor building (100), and external air is introduced into the internal space (T) through the first air passage (110).

[0028] Even if the water in the passive cooling unit (400) is exhausted through the first air communication unit (110), cooling can continue by smoothly flowing air to the outer wall of the containment vessel (300).

[0029] The first air ventilation unit (110) may be configured in multiple units on the upper portion of the reactor building (100), but is not limited thereto. In addition, although not illustrated, a separate intake / exhaust device may be additionally installed on the reactor building (100) to enable the introduction and exhaust of air into and from the internal space (T).

[0030] The reactor building (100) further includes a support structure (120) that supports the containment vessel (300), and a second air communication portion (121) is formed in at least a portion of the support structure (120) to allow the flow of external atmosphere introduced into the internal space (T).

[0031] The external air introduced into the internal space (T) through the second air communication unit (121) flows smoothly to the upper and lower parts of the containment vessel (300), and by this flow, the external surface of the containment vessel (300) can come into contact with the atmosphere of the internal space (T), and as a result, the containment vessel (300) is cooled by the atmosphere introduced into the internal space (T).

[0032] The integral reactor (200) is located within the reactor building (100) and includes a core (210), a steam generator (220), a pressure relief valve (230), and a circulation valve (240). Although not shown, a separate passive residual heat removal system may be additionally installed, which is connected to the steam generator (220) and can remove heat generated from the core (210) to a containment vessel (300).

[0033] Here, the steam generator (220) is located above the core (210), and the pressure relief valve (230) is located above the steam generator (220).

[0034] The pressure relief valve (230) discharges the steam generated by the core (210) into the containment vessel (300), and the circulation valve (240) recirculates the condensate condensed inside the containment vessel (300) back into the integral reactor (200).

[0035] Although not shown, a separate fixing structure may be further provided for erecting and fixing the integral reactor (200), and the integral reactor (200) may be fixed to the containment vessel (300) through the fixing structure.

[0036] Figure 3 illustrates a support structure that supports the containment vessel.

[0037] The containment vessel (300) is located within the reactor building (100), accommodates an integral reactor (200), and has a cooling space (S) surrounding the integral reactor (200).

[0038] The containment vessel (300) can be made of a steel structure, and the containment vessel (300) is fixed to the reactor building (100) without touching the ground of the reactor building (100) by a support structure (120).

[0039] The containment vessel (300) includes a first heat exchanger (310) and a recirculation collection tank (320).

[0040] The first heat exchanger (310) is placed in the cooling space (S) and cools and condenses the discharged steam. Specifically, the first heat exchanger (310) supplies (transfers) cooling water, the temperature of which has been increased by heat exchange with the steam discharged from the integral reactor (200) to the cooling space (S), to the passive cooling unit (400).

[0041] The first heat exchanger (310) is connected to the passive cooling unit (400) through the second circulation unit (450), and the cooling water whose temperature has increased through heat exchange with the steam discharged from the integral reactor (200) to the cooling space (S) is supplied to the passive cooling unit (400) through the second circulation unit (450), and thereafter, the cooling water is cooled through the passive cooling water (400), and the cooling water that has completed cooling is supplied to the first heat exchanger (310) through the second circulation unit (450).

[0042] Although not shown, in the present invention, the first heat exchanger (310) may be arranged in a ring-shaped manner surrounding the integral reactor (200) within the containment vessel (300), but is not limited thereto.

[0043] The recirculation collection tank (320) is placed below the first heat exchanger (310) and collects condensate that condenses and falls on the surface of the first heat exchanger (310). The condensate stored in the recirculation collection tank (320) is resupplied into the interior of the integrated reactor (200) through the circulation valve (240).

[0044] The passive cooling unit (400) is located outside the containment vessel (300), condenses steam generated from the steam generator (220) through passive heat exchange, resupplies it to the steam generator, and passively removes heat generated from the first heat exchanger (310).

[0045] The passive cooling unit (400) includes a cooling water tank (410), a second heat exchanger (420), an air flow structure (430), a first circulation unit (440), a second circulation unit (450), and a moisture separation unit (460).

[0046] The cooling water tank (410) has a receiving space (W) formed therein where cooling water is received, and a second heat exchanger (420) is positioned within the cooling water tank (410). In the present invention, only one heat exchanger, i.e., the second heat exchanger (420), is shown as being positioned within the cooling water tank (410), but the present invention is not limited thereto.

[0047] A first communication port (411) is formed on the upper wall of the cooling water tank (410). Here, steam generated in the receiving space (W) is discharged through the first communication port (411), or air flowing in from the air flow structure (430) is introduced.

[0048] During normal operation, the steam generated in the steam generator (220) is not transferred to the second heat exchanger (420), but to the turbine. The pipe penetrating the containment vessel (300) is automatically isolated upon receiving a signal to prevent radioactive materials from leaking out of the containment vessel (300) in the event of an accident, and the valve supplying steam to the second heat exchanger (420) is simultaneously opened. (Although not shown) The containment vessel isolation valve is directly connected to the outer base material of the containment vessel, so there is no need to consider pipe damage. (Although not shown) The second heat exchanger operating valve opens in a safe open direction (Fail-safe) when power is lost or an operating signal is received.

[0049] The second heat exchanger (420) cools and condenses the steam discharged from the steam generator (220) in the integral reactor (200) through heat exchange.

[0050] The second heat exchanger (420) is connected to the steam generator (220) through the first circulation section (440), and the steam generated from the steam generator (220) is transferred to the second heat exchanger (420) through the first circulation section (440), and the second heat exchanger (420) cools and condenses the steam through heat exchange using cooling water in the cooling water tank (410).

[0051] The air flow structure (430) is located at the top of the cooling water tank (410) and forms an air flow space (A).

[0052] A second communication port (431) is formed on the wall surface of the air flow structure (430) to connect the air flow space (A) with the external atmosphere. Air introduced into the air flow space (A) through the second communication port (431) can be introduced into the receiving space (W) through the first communication port (411).

[0053] The first circulation section (440) is composed of a closed loop in which a steam generator (220) and a second heat exchanger (420) are connected to each other. Here, the passive cooling section (400) is positioned above the containment vessel (300), so that the cooling water of the first circulation section (440), which is connected to the closed loop, is smoothly circulated.

[0054] The second circulation section (450) includes a first discharge pipe (451) and a first supply pipe (452).

[0055] The first discharge pipe (451) transfers the heated cooling water inside the first heat exchanger (310) to the cooling water tank (410), and the first supply pipe (452) transfers the cooling water from the cooling water tank (410) to the first heat exchanger (310).

[0056] The moisture separation unit (460) is at least partially connected to the first communication port (411) and separates moisture from the vapor discharged into the air flow space (A) through the first communication port (411).

[0057] The vapor that escapes from the receiving space (W) to the air flow space (A) by the moisture separator (460) is separated into gas and liquid states, and the separated liquid is re-stored in the cooling water tank (410).

[0058] Although not shown, it may further include an external reservoir located outside the reactor building and capable of receiving cooling water from an external source.

[0059] The external tank is connected to the cooling water tank (410), and the cooling water in the external tank is used when replenishing the cooling water in the cooling water tank (410).

[0060] FIG. 2 is a diagram of a passive cooling system of a small modular reactor according to another embodiment of the present invention.

[0061] Referring to FIG. 2, a passive cooling system (10) in another embodiment includes a reactor building (100), an integral reactor (200), a containment vessel (300), and a passive cooling unit (400').

[0062] The passive cooling unit (400') further includes a partition wall (470) that divides the cooling water into a first zone and a second zone. Within the passive cooling unit (400'), the second heat exchanger (420) is located in the first zone (a), and the second circulation unit (450) is connected to the second zone (b).

[0063] A third communication port (471) is formed in the bulkhead (470) to allow the flow of cooling water between the first zone (a) and the second zone (b).

[0064] According to the present invention, the outside of the containment vessel can be operated in a dry state, corrosion of the outer wall of the containment vessel can be prevented, and since the devices and instruments existing on the outer wall of the containment vessel can be operated in a dry state, maintenance and management become easier.

[0065] Furthermore, because the outer wall of the containment vessel remains dry at all times, unlike conventional submerged containment vessels, heat is transferred solely to the passive cooling section. This prevents vaporization of the reactor building, and passive cooling is smoothly achieved through natural convection heat transfer by the inflowing air. Additionally, the introduction of the passive cooling section reduces the maximum pressure within the containment vessel, significantly reducing manufacturing and maintenance costs through designs capable of lowering this pressure.

[0066] The embodiments of the present invention described above and illustrated in the drawings should not be construed as limiting the technical concept of the present invention. The scope of protection of the present invention is limited only by the matters set forth in the claims, and those skilled in the art will be able to make various improvements and modifications to the technical concept of the present invention. Accordingly, such improvements and modifications, as long as they are obvious to those skilled in the art, will fall within the scope of protection of the present invention.

Claims

1. Regarding the passive cooling system of a small modular reactor, A reactor building forming an interior space; An integral reactor located within the reactor building and including a core and a steam generator; A containment vessel located within the reactor building, accommodating the integral reactor and having a cooling space surrounding the integral reactor; A first heat exchanger formed in the above cooling space and cooling and condensing the steam discharged from the integrated reactor; and A passive cooling system for a small modular reactor, comprising: a passive cooling unit for condensing steam discharged from the steam generator through passive heat exchange and re-supplying it to the steam generator, and passively removing heat generated in the first heat exchanger.

2. In paragraph 1, The above first heat exchanger is located above the integral reactor, A passive cooling system of a small modular reactor in which the outer surface of the above containment vessel is in contact with the atmosphere of the internal space.

3. In paragraph 1, The above passive cooling unit, A coolant tank containing coolant; A second heat exchanger located within the above cooling water; An airflow structure located at the upper part of the above cooling water tank and forming an airflow space; A first circulation section connecting the steam generator and the second heat exchanger; and A passive cooling system for a small modular reactor, comprising: a second circulation section connecting the first heat exchanger and the cooling water cooler; 4. In paragraph 3, A first communication port is formed on the upper wall of the above cooling water tank. A passive cooling system for a small modular reactor, in which a second communication port is formed on the wall surface of the above airflow structure to connect the above airflow space with the outside atmosphere.

5. In paragraph 3, The above passive cooling unit, A passive cooling system for a small modular reactor further comprising a moisture separator that is at least partially connected to the first communication port and separates moisture from steam discharged into the airflow space through the first communication port.

6. In paragraph 4, The above first circulation section, A passive cooling system of a small modular reactor consisting of a closed loop in which the above steam generator and the second heat exchanger are connected to each other.

7. In paragraph 3, The above second circulation section, A first discharge pipe that transfers the heated cooling water inside the first heat exchanger to the cooling water tank; and A passive cooling system for a small modular reactor, comprising: a first supply pipe for delivering the cooling water from the cooling water tank to the first heat exchanger; 8. In paragraph 3, The above passive cooling unit is, Further comprising a bulkhead dividing the cooling water into a first zone and a second zone, The above second heat exchanger is located in the above first zone, The above second circulation section is a passive cooling system of a small modular reactor connected to the above second section.

9. In paragraph 8, In the above bulkhead, A passive cooling system of a small modular reactor having a third communication port formed to enable the flow of coolant between the first and second zones.

10. In paragraph 1, A first air vent is formed on the upper wall of the above reactor building. A passive cooling system for a small modular reactor in which outside air is introduced into the internal space through the first air passage.

11. In paragraph 1, The above reactor building, Further comprising a support structure supporting the above containment vessel, A passive cooling system for a small modular reactor, wherein a second air passage is formed in at least a portion of the above support structure to allow the flow of external air introduced into the internal space.

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