Spent fuel storage system for reusing decommissioned nuclear power plant

Abstract

The present invention relates to a spent fuel storage system for reusing a decommissioned nuclear power plant, the spent fuel storage system comprising: a refueling pool which is located inside a containment building of the decommissioned nuclear power plant and has a storage space filled with cooling water; a storage rack which is installed inside the refueling pool and stores spent fuel; and a residual heat removal unit for cooling the cooling water heated by the spent fuel.

Description

Spent fuel storage system for reusing decommissioned nuclear power plants

[0001] The present invention relates to a spent fuel storage system for reusing nuclear power plants that have ceased operation.

[0002] Nuclear fuel from nuclear power plants that have ceased operation (hereinafter referred to as “spent fuel”) is stored in a storage location while contained in specially designed storage containers.

[0003] Storage methods for spent fuel are broadly classified into wet storage and dry storage methods. Until the mid-1980s, wet storage methods, which have extensive application experience, were primarily used; however, dry storage methods, which are advantageous in terms of capacity expansion and long-term management, were adopted, and dry storage facilities applying dry storage methods are being utilized in many countries. Meanwhile, spent fuel is transferred to spent fuel storage tanks for storage and safekeeping.

[0004] Domestic nuclear power plants lack separate interim or permanent storage facilities for such spent fuel, so the entire amount is temporarily stored on-site.

[0005] Therefore, since current spent fuel storage is nearly saturated due to long-term accumulation in separate temporary storage facilities, securing additional storage facilities is essential for stable nuclear power plant operation.

[0006] The objective of the present invention is to provide a spent fuel storage system for reusing nuclear power plants that have ceased operation.

[0007] The present invention relates to a spent fuel storage system for reusing a nuclear power plant that has ceased operation, comprising: a reloading tank located inside the containment building of the nuclear power plant that has ceased operation and having a storage space formed therein for filling with cooling water; a storage rack installed inside the reloading tank for storing spent fuel; and a residual heat removal unit for cooling the cooling water heated by the spent fuel.

[0008] The above residual heat removal unit may use a residual heat removal system that was used during the normal operation of the above nuclear power plant.

[0009] The above residual heat removal unit may include: a decommissioned reactor that is disposed adjacent to the reloading tank so as not to be included in the storage space of the reloading tank and has cooling water filled inside; a cooling water cooling pipe extending from the internal space of the decommissioned reactor to the storage space; and a cooling system for cooling the cooling water inside the decommissioned reactor.

[0010] The above residual heat removal unit may further include a flange coupled to the upper part of the above-mentioned nuclear reactor to form the internal space.

[0011] The above cooling water cooling pipe includes: a discharge pipe fixed to the flange and supplying cooling water heated by spent fuel in the storage space to the internal space of the spent reactor; and a supply pipe fixed to the flange and supplying cooling water cooled by the cooling system to the storage space; wherein the discharge pipe may have a flow path separated from the internal space.

[0012] The above cooling system may include a heat exchanger that cools cooling water introduced from the spent reactor; and a pump located between the spent reactor and the heat exchanger.

[0013] The above storage space includes: a first storage space located above the decommissioned reactor; a second storage space connected to the first storage space and forming a step in the vertical direction with respect to the first storage space; and a transfer space for transferring the spent fuel; wherein at least a portion of the second storage space may be connected to the transfer space.

[0014] The present invention relates to a method for storing spent fuel by reusing a nuclear power plant that has ceased operation, comprising the steps of: providing a storage space capable of accommodating cooling water in a reloading pool of the nuclear power plant that has ceased operation; installing a storage rack in the storage space and filling it with cooling water; and storing spent fuel in the storage rack.

[0015] The method further includes a step of cooling the cooling water heated by the above-mentioned spent fuel through a residual heat removal unit, and comprises: a spent reactor that is disposed adjacent to the reloading tank so as not to be included in the storage space of the reloading tank and has cooling water filled inside; a cooling water cooling pipe extending from the internal space of the spent reactor to the storage space; and a cooling system for cooling the cooling water inside the spent reactor; wherein the cooling step through the residual heat removal unit may include a step of discharging the heated cooling water through the cooling water cooling pipe to the spent reactor; and a step of cooling the discharged cooling water through the cooling system.

[0016] The above cooling system includes a heat exchanger for cooling water introduced from the spent reactor; and a pump located between the spent reactor and the heat exchanger; and the cooling water cooling step through the cooling system may include the step of supplying heated cooling water introduced into the internal space of the spent reactor to the heat exchanger using the pump; and the step of cooling the cooling water using the heat exchanger.

[0017] According to the present invention, a spent fuel storage system for reusing a nuclear power plant that has ceased use is provided.

[0018] FIG. 1 shows a spent fuel storage system for reusing a nuclear power plant that has ceased use according to an embodiment of the present invention, and

[0019] FIG. 2 shows a reloading tank of a spent fuel storage system for reusing a decommissioned nuclear power plant according to an embodiment of the present invention, and

[0020] FIGS. 3 and 4 show a storage rack of a spent fuel storage system for recycling a decommissioned nuclear power plant according to an embodiment of the present invention, and

[0021] FIGS. 5 and 6 illustrate a residual heat removal unit of a spent fuel storage system for recycling a decommissioned nuclear power plant according to an embodiment of the present invention, and

[0022] FIG. 7 is a flowchart illustrating a method for storing spent fuel by reusing a nuclear power plant that has ceased use according to an embodiment of the present invention.

[0023] The present invention will be described in more detail below with reference to the drawings.

[0024] The attached drawings are merely examples illustrated to further explain the technical concept of the present invention, and therefore the concept of the present invention is not limited to the attached drawings. Additionally, the sizes and spacing, etc., in the attached drawings may be exaggerated from reality to explain the relationships between the components.

[0025] FIG. 1 shows a spent fuel storage system for reusing a nuclear power plant that has ceased use according to an embodiment of the present invention, FIG. 2 shows a reloading tank of a spent fuel storage system for reusing a nuclear power plant that has ceased use according to an embodiment of the present invention, FIG. 3 and FIG. 4 show a storage rack of a spent fuel storage system for recycling a nuclear power plant that has ceased use according to an embodiment of the present invention, and FIG. 5 and FIG. 6 show a residual heat removal unit of a spent fuel storage system for recycling a nuclear power plant that has ceased use according to an embodiment of the present invention.

[0026] As illustrated in FIGS. 1 to 6, a spent fuel storage system (10) according to one embodiment of the present invention includes a reloading tank (100), a storage rack (200), and a residual heat removal unit (300).

[0027] Referring to FIG. 2, the reloading tank (100) is located inside the containment building of a nuclear power plant that has ceased operation, and a storage space (110) filled with cooling water is formed inside.

[0028] The reloading tank (100) is located inside the nuclear power plant containment building, and the reloading tank currently in use at the existing nuclear power plant can be used as is.

[0029] (Although not shown) a separate reinforcing structure may be installed at the bottom of the storage space (110) of the reload tank (100), and such reinforcing structure may serve to support the bottom and side of the storage rack (200).

[0030] The storage rack (200) is installed inside the reload tank (100) and stores fuel after use.

[0031] In one embodiment of the present invention, a storage rack (200) is installed within a storage space (110) of a reloading tank (100), and the storage space (110) includes a first storage space (111), a second storage space (112), and a transfer space (113).

[0032] The first storage space (111) is located at the top of the decommissioned reactor (310) described later.

[0033] The second storage space (112) is connected to the first storage space (111) and forms a step in the vertical direction with respect to the first storage space (111).

[0034] The transfer space (113) is connected to the second storage space (112) and transfers used fuel from the first storage space (111) and the second storage space (112) to the outside.

[0035] In one embodiment of the present invention, the storage rack (200) includes an upper storage rack (210) and a lower storage rack (220), and used fuel is inserted into the interior through the upper / lower storage racks (210, 220) which have an open top. Here, the upper storage rack (210) is located within the first storage space (111), and the lower storage rack (220) is located across the second storage space (112) and the transfer space (113).

[0036] The upper storage rack (210) and the lower storage rack (220) are exemplarily described as being installed with the upper part open so that used fuel can be inserted inside, but are not necessarily limited thereto.

[0037] The upper storage rack (210) and the lower storage rack (220) can be designed so that each of the multiple used fuel storage cells is arranged at equal intervals. Additionally, (although not illustrated) a separate fixing plate may be further installed to secure the upper / lower storage racks (210, 220) within the reload tank (100).

[0038] The residual heat removal unit (300) cools the cooling water heated by the spent fuel. In one embodiment of the present invention, the residual heat removal unit (300) uses the cooling system that was used during the normal operation of the nuclear power plant as is in the residual heat removal system.

[0039] Referring to FIGS. 1, 5 and 6, the residual heat removal unit (300) includes a decommissioned reactor (310), a cooling water cooling pipe (320), and a cooling system (330).

[0040] Referring to FIG. 5, the decommissioned reactor (310) is positioned adjacent to the reloading tank (100) so as not to be included in the storage space of the reloading tank (100), and is filled with cooling water inside.

[0041] The decommissioned reactor (310) separates the existing upper head and attaches a new flange (311) to form an internal space into which cooling water can be filled.

[0042] The cooling water cooling pipe (320) extends from the internal space of the decommissioned reactor (310) to the storage space (110) of the reloading tank (100) and includes a discharge pipe (321) and a supply pipe (322).

[0043] The discharge pipe (321) is fixed to the flange (311) and supplies cooling water heated by heat generated by spent fuel stored in the storage space (110) of the reloading tank (100) to the internal space of the decommissioned reactor (310).

[0044] The supply pipe (322) is fixed to the flange (311) and supplies cooling water, cooled by the cooling system (300) described later, to the storage space (110).

[0045] In one embodiment of the present invention, a separate spray nozzle is installed in the supply pipe (322) installed in the storage space (110) to spray cooled water, but the invention is not limited thereto.

[0046] Referring to FIG. 1, the cooling system (330) cools the cooling water in the decommissioned reactor (310) and includes a heat exchanger (331) and a pump (332).

[0047] The heat exchanger (331) cools the cooling water flowing in from the decommissioned reactor (310).

[0048] The pump (332) is located between the decommissioned reactor (310) and the heat exchanger (331) and can provide pumping driving force to supply cooling water discharged through the decommissioned reactor (310) to the heat exchanger (331).

[0049] The cooling system (330) includes a circulation line connected to the decommissioned reactor (310), and through the circulation line, cooling water cooled through the heat exchanger (331) is supplied to the storage space (110) of the reloading tank (100).

[0050] Specifically, referring to FIG. 1, the circulation line can be separated into a flow path that delivers heated cooling water through a discharge pipe (321) to a heat exchanger (331) via a pump (332), and a flow path that delivers cooled cooling water through a heat exchanger (331) to a storage space (110) via a supply pipe (322).

[0051] At this time, the flow path and supply pipe (322) that deliver the cooling water cooled through the heat exchanger (331) among the separated flow paths are connected to each other, and through this connection, the cooled cooling water is supplied to the storage space (110) in a state where the temperature rise caused by the cooling water in the spent reactor (310) is minimized.

[0052] Referring to FIG. 1, in one embodiment of the present invention, the discharge pipe (321) is shown as being separated and not connected to the flow path that delivers heated cooling water to the heat exchanger (331) via the pump (332), but is not limited thereto. In another embodiment, the discharge pipe (321) may be connected to the flow path that delivers heated cooling water to the heat exchanger (331) via the pump (332).

[0053] Referring to FIG. 7, a method for storing spent fuel by reusing a nuclear power plant that has ceased use according to an embodiment of the present invention will be described.

[0054] FIG. 7 is a flowchart illustrating a method for storing spent fuel by reusing a nuclear power plant that has ceased use according to an embodiment of the present invention.

[0055] First, a storage space (110) capable of accommodating cooling water is provided in the reloading tank (100) of a decommissioned nuclear power plant. (S100)

[0056] The step of providing a storage space (110) involves providing a circular internal space within the reactor containment building body of a nuclear power plant that has ceased operation or has been decided for decommissioning, such that a storage rack (200) for storing spent fuel can be inserted therein. Accordingly, it is possible to utilize the existing reactor containment building as a means for storing spent fuel without using a separate structure for storing spent fuel, thereby making it easy to secure a space for storing spent fuel.

[0057] In addition, it is possible to perform decontamination work on the internal facilities and structures of the reactor containment building in advance during the step (S100) of preparing the storage space (110). Furthermore, a separate reinforcing structure capable of supporting the bottom and sides of the storage rack (200) to be subsequently installed at the bottom of the storage space (110) may also be installed.

[0058] As a subsequent step, a storage rack (200) is installed in the storage space (110) provided, and cooling water is filled inside. (S200)

[0059] A storage rack (200) is installed within a storage space (110) of a reloading tank (100) that includes a first storage space (111), a second storage space (112), and a transfer space (113). Here, an upper storage rack (210) is installed in the first storage space (111), and a lower storage rack (220) is installed across the second storage space (112) and the transfer space (113).

[0060] The upper storage rack (210) and the lower storage rack (220) can be installed such that each of the multiple used fuel storage cells is spaced at equal intervals, and (although not illustrated) the installation can be made smoother by using a separate fixing plate to secure the upper / lower storage racks (210, 220) within the reload tank (100).

[0061] Afterwards, used fuel is stored in a storage rack (200) filled with coolant. (S300)

[0062] Next, the cooling water heated by the spent fuel is cooled through the residual heat removal unit (300). (S400)

[0063] The cooling step (S400) through the residual heat removal unit (300) involves discharging heated cooling water to the decommissioned reactor (310) through the cooling water cooling pipe (320), and then cooling the discharged cooling water through the cooling system (330).

[0064] Specifically, cooling water heated by heat generated by spent fuel stored in the storage space (110) of the reloading tank (100) is supplied to the internal space of the decommissioned reactor (310) through the discharge pipe (321). Subsequently, the heated cooling water inside the decommissioned reactor (310) is supplied to the heat exchanger (331) through the circulation line and pump (332), and the cooling water is cooled by heat exchange.

[0065] Cooling water cooled by the heat exchanger is supplied to the storage space (110) in the reloading tank (100) by the supply pipe (322).

[0066] As described above, the method for storing spent fuel by reusing a decommissioned nuclear power plant according to one embodiment of the present invention is economical because it does not require the construction of a separate new facility for processing spent fuel, and it allows the continued use of the reactor containment building, whose stability, including radiation shielding and seismic performance, has already been verified. Furthermore, the method of storing spent fuel by reusing a decommissioned nuclear power plant offers the advantage of requiring less cost compared to the installation of existing new dry storage facilities, while enabling the securing of a facility capable of storing a large amount of spent fuel in a short period of time.

[0067] In addition, by recycling most of the existing facilities within the nuclear power plant containment building, such as the reloading pool and residual heat removal system, it is possible to be environmentally friendly and simultaneously reduce the amount of waste generated.

[0068] Although the present invention has been described with reference to an embodiment illustrated in the accompanying drawings, this is merely illustrative, and those skilled in the art will understand that various modifications can be made to the present invention. Accordingly, the technical scope of protection of the present invention should be determined by the appended claims.

Claims

1. In a spent fuel storage system for reusing decommissioned nuclear power plants, A reloading tank located inside the containment building of a decommissioned nuclear power plant, having a storage space formed for filling with coolant; A storage rack installed inside the above-mentioned reloading tank and storing spent fuel; and A spent fuel storage system comprising: a residual heat removal unit for cooling water heated by the spent fuel.

2. In Paragraph 1, The above residual heat removal unit is, A spent fuel storage system using a residual heat removal system that was used during the normal operation of the above-mentioned nuclear power plant.

3. In Paragraph 2, The above residual heat removal unit is, A decommissioned nuclear reactor positioned adjacent to the reloading tank so as not to be included in the storage space of the reloading tank, and filled with cooling water inside; Cooling water cooling pipes extending from the internal space of the above-mentioned decommissioned reactor to the storage space; and A spent fuel storage system comprising a cooling system for cooling the cooling water inside the above-mentioned spent nuclear reactor.

4. In Paragraph 3, The above residual heat removal unit is, A spent fuel storage system further comprising a flange coupled to the upper part of the above-mentioned decommissioned reactor to form the internal space.

5. In Paragraph 3, The above cooling water cooling pipe is, A discharge pipe fixed to the above flange and supplying cooling water heated by spent fuel in the storage space to the internal space of the above-mentioned spent reactor; and It includes a supply pipe that is fixed to the above flange and supplies cooling water cooled by the above cooling system to the above storage space; The above discharge pipe is a spent fuel storage system having a flow path separated from the above internal space.

6. In Paragraph 3, The above cooling system is, A heat exchanger for cooling the cooling water flowing in from the above-mentioned spent nuclear reactor; and A spent fuel storage system comprising: a pump located between the above-mentioned spent reactor and the above-mentioned heat exchanger.

7. In Paragraph 3, The above storage space is, A first storage space located at the top of the above-mentioned decommissioned reactor; A second storage space connected to the first storage space and forming a step in the vertical direction with respect to the first storage space; and A transfer space for transferring the above-mentioned used fuel; is included, A spent fuel storage system in which at least a portion of the second storage space is connected to the transfer space.

8. In a method of storing spent fuel by reusing a decommissioned nuclear power plant, A step of providing a storage space capable of accommodating cooling water in the reloading pool of a decommissioned nuclear power plant; A step of installing a storage rack in the above storage space and filling the interior with cooling water; and A method for storing spent fuel comprising the step of storing spent fuel in the storage rack above.

9. In Paragraph 8, The method further includes the step of cooling the cooling water heated by the above-mentioned used fuel through a residual heat removal unit, and A decommissioned reactor disposed adjacent to the decommissioned reactor and filled with cooling water, so as not to be included in the storage space of the decommissioned reactor; a cooling water cooling pipe extending from the internal space of the decommissioned reactor to the storage space; and a cooling system for cooling the cooling water inside the decommissioned reactor; comprising The cooling step through the above residual heat removal unit is, A step of discharging heated cooling water through the above cooling water cooling pipe to the above-mentioned spent reactor; and A method for storing spent fuel comprising the step of cooling the discharged coolant through the cooling system.

10. In Paragraph 8, The above cooling system includes: a heat exchanger for cooling water introduced from the spent reactor; and a pump located between the spent reactor and the heat exchanger. The cooling water cooling step through the above cooling system is, A step of supplying heated cooling water introduced into the internal space of the decommissioned reactor using the above pump to the heat exchanger; and A method for storing spent fuel comprising the step of cooling the cooling water using the heat exchanger.

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