Shielding device

Abstract

To provide a shielding device which presents a better operability and is smaller in size than an existing one.SOLUTION: The present invention includes: an upper lead storage room 1 for storing lead grains 15; a meter shielding unit 4 arranged around the meter 5; a heat exchanger 7 for cooling the lead grains 15; a ball lifting machine 8 for supplying the lead grains 15 after cooling into the upper lead storage unit 1; a detector 9 for outputting an opening-closing operation signal of an opening-closing unit 2 provided in the upper lead storage room 1; a pipe 3A connecting the opening-closing unit 2 and the meter shielding unit 4; a pipe 3B connecting the meter shielding unit 4 and the heat exchanger 7 to each other; and pipes 3C and 3D connecting the heat exchanger 7 and the upper lead storage room 1 to each other.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a shielding device that also has a cooling function. [Background technology]

[0002] In response to the problem that radiation irradiating the elements that make up a pressure transmission device causes the elements to deteriorate, causing pressure measurement values ​​to drift and preventing accurate numerical values ​​from being output, Patent Document 1 describes a pressure transmission device that transmits pressure received by a pressure-receiving diaphragm to a sensor, which is configured to include a radiation measuring device that measures the amount of radiation irradiated to the pressure transmission device, a drift diagnosis device that diagnoses the amount of drift in the pressure transmission device, a database that stores drift data due to radiation for each component of the pressure transmission device, a drift correction device that corrects the drift, and a pressure value display device that displays the pressure measurement value. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2018-119820 A Summary of the Invention [Problem to be solved by the invention]

[0004] In environments exposed to radiation, such as nuclear power plants, there is a need to measure various physical quantities, including temperature, water level, radiation, etc. For measuring instruments that are exposed to radiation, measures are taken such as shielding with lead or keeping the instruments away from the radiation source.

[0005] In plants such as nuclear power plants, instruments such as pressure gauges and flow meters used to know the operating status of the plant are required to function normally without malfunction or failure even in a severe accident environment (see, for example, Patent Document 1).

[0006] Therefore, in order for the instruments to function properly, it is necessary to take measures against radiation and heat. However, in existing plants, the space to install new equipment to take these measures is limited, so separate measures must be taken.

[0007] For example, a conventional solution was to install lead shielding and a cooler to cool the instruments separately, but this resulted in a large and heavy casing structure, leaving room for improvement in the ease of installation and relocation.

[0008] The present invention provides a compact shielding device that is easier to work with than conventional devices. [Means for solving the problem]

[0009] The present invention includes multiple means for solving the above-mentioned problems, and one example is a shielding device for protecting an instrument from radiation, comprising a storage chamber for storing lead pellets, an instrument shielding section arranged around the instrument, a heat exchanger for cooling the lead pellets, a supply section for supplying the cooled lead pellets to the storage chamber, and a command section for outputting an opening / closing operation command signal for an opening / closing section provided in the storage chamber. Effect of the Invention

[0010] According to the present invention, it is possible to provide a compact shielding device that is easier to work with than the conventional device. Problems, configurations and effects other than those described above will become apparent from the following description of the embodiments. [Brief description of the drawings]

[0011] [Figure 1] 1 is a diagram showing a schematic configuration of a shading device according to an embodiment of the present invention; [Diagram 2] 4 is a flowchart showing the flow of operations of the shading device according to the embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] An embodiment of the shielding device of the present invention will be described with reference to Figures 1 and 2. In the drawings used in this specification, the same or corresponding components are denoted by the same or similar reference numerals, and repeated description of these components may be omitted.

[0013] First, the overall configuration of a shading device 20 will be described with reference to Fig. 1. Fig. 1 is a diagram showing a schematic configuration of a shading device according to an embodiment of the present invention.

[0014] 1 is a device for protecting instruments 5, such as pressure gauges and flow meters, used to know the operating state of a plant such as a nuclear power plant, from radiation, and includes an upper lead storage chamber 1, a switch section 2, an instrument shielding section 4, a lower lead storage chamber 6, a heat exchanger 7, a lifting machine 8, a detector 9, pipes 3A, 3B, 3C, and 3D, and signal lines 10, 11, and 12. It is desirable for these shielding devices 20 to be permanently installed around the instruments 5, but they may be temporary.

[0015] The upper lead storage chamber 1 is a facility that normally stores all the lead pellets 15, and is located vertically above the instrument shielding section 4, which is upstream of the instruments 5, and has an opening / closing section 2 at its bottom. This structure, which uses lead pellets 15 and stores them inside the upper lead storage chamber 1, has the advantage of being more compact than conventional lead shields, making it easier to transport during construction.

[0016] There are no particular limitations on the particle size or shape of the lead pellets 15 to be stored, and the speed and amount of the lead pellets 15 circulated are also appropriately determined depending on the radiation dose and temperature in the environment in which the device is installed.

[0017] The detector 9 is a control device that outputs an opening / closing operation command signal for the opening / closing unit 2 provided in the upper lead storage room 1, and when it detects an abnormality such as an earthquake, temperature, or radiation level, it outputs an opening operation command signal to the opening / closing unit 2 via signal line 10, a start command signal to the heat exchanger 7 via signal line 11, and a start command signal to the ball lifting machine 8 via signal line 12.

[0018] In the illustrated example, the detector 9 outputs a command signal when it detects an abnormality such as an earthquake, temperature, or radiation level. However, the detector may be configured to output a command signal to the opening / closing section 2, the heat exchanger 7, or the ball lifting machine 8 when it is determined that a command signal instruction from an operator has been input.

[0019] In addition, the timing at which the detector 9 outputs a closing operation command signal or a stop command signal (timing at which the circulation of the lead pellets 15 is stopped) is not particularly limited to the timing at which it is determined that the necessary measurements by the instrument 5 have been completed, the timing at which the detector 9 detects that the abnormality has been resolved, the timing at which a specific time has elapsed since the output of an operator's instruction, an opening operation command signal, etc.

[0020] The instrument shielding section 4 is shaped to surround the instrument 5 and has a configuration in which lead particles 15 circulate inside. More specifically, it is composed of an object such as a sphere or a rectangular parallelepiped covered with transparent resin with a double-structure space for circulating lead particles 15, with one part open for measuring the physical quantity of the instrument 5.

[0021] Therefore, when the opening / closing section 2 is opened, the lead particles 15 flow by gravity through the piping 3A to the instrument shielding section 4, and a structure is realized in which the lead particles 15 circulate inside the double structure, covering the instruments 5 with lead, thereby protecting the instruments 5 by blocking radiation and heat from the outside.

[0022] Lead particles 15 circulating within the instrument shielding section 4 move to the lower lead storage chamber 6 via piping 3B.

[0023] The lower lead storage chamber 6 is a facility for storing the lead pellets 15 that have flowed in from the instrument shielding section 4, and a heat exchanger 7 for cooling the lead pellets 15 is provided in part of it. Thus, the heat exchanger 7 is disposed vertically below the instrument shielding section 4.

[0024] The heat exchanger 7 is a device that cools by directly exchanging heat with the lead pellets 15, and the hot lead pellets 15 are cooled in the lower lead storage room 6. The lead pellets 15 cooled by the heat exchanger 7 move to the lifting machine 8 located vertically below the instrument shielding section 4 via the piping 3C.

[0025] The heat exchange method in the heat exchanger 7 is not particularly limited, and may be appropriately determined according to the environment in which it is installed, such as a method of blowing gas such as air cooled to below room temperature, or a method of contacting cooled lead with a liquid that does not react with lead.

[0026] The heat exchanger 7 does not need to be of a type that directly exchanges heat with the lead grains 15, but may be of a type that indirectly exchanges heat with the lead grains 15.

[0027] The lifting machine 8 is a device that lifts the cooled lead pellets 15 in the lower lead storage chamber 6 vertically upward toward the upper lead storage chamber 1, and is composed of various mechanisms that physically launch the lead pellets 15 toward the upper lead storage chamber 1 via piping 3D, as well as a pumping mechanism using pulleys, conveyor belts, baskets, etc.

[0028] In this manner, the lead pellets 15 circulate around the instrument shielding portion 4 in this series of steps until the ball lifting machine 8 stops, thereby protecting the instrument 5 from radiation and heat even in a severe accident environment.

[0029] Piping 3A connects the opening / closing section 2 and the instrument shielding section 4, pipe 3B connects the instrument shielding section 4 and the heat exchanger 7, pipe 3C connects the lower lead storage chamber 6 in which the heat exchanger 7 is located and the balling machine 8, and pipe 3D connects the balling machine 8 and the upper lead storage chamber 1.

[0030] The upper lead storage chamber 1, the instrument shielding section 4, the lower lead storage chamber 6, the lifting machine 8, and the pipes 3A, 3B, 3C, and 3D are assumed to be filled with air, but the material to be filled is not limited to air. It does not have to be a gas, and liquids such as water or a special refrigerant can be filled.

[0031] Next, the flow of operations of the shading device according to the embodiment of the present invention will be described with reference to Fig. 2. Fig. 2 is a flowchart showing the flow of operations of the shading device.

[0032] As shown in FIG. 2, when operation starts and detector 9 determines that it has detected an abnormality such as an earthquake, temperature, radiation level, etc. (S1), detector 9 outputs an opening operation command signal to opening / closing unit 2 via signal line 10, and opens opening / closing unit 2 (S2).

[0033] As a result, the lead pellets 15 stored in the upper lead storage chamber 1 are supplied by free fall to the instrument shielding portion 4 via the pipe 3A, shielding the instrument 5 from radiation entering the instrument 5 (S3).

[0034] Furthermore, due to further free fall, the lead pellets 15 are stored in the lower lead storage chamber 6 via the pipe 3B (S4), where the lead pellets 15 are cooled by the heat exchanger 7 (S5). After that, the cooled lead pellets 15 are transported by the ball lifter 8 to the upper lead storage chamber 1 (S6), where the lead pellets 15 are stored in the upper lead storage chamber 1 (S7), and the lead pellets 15 are supplied to the instrument shielding section 4 by free fall again via the pipe 3A, and this cycle is repeated.

[0035] As described above, the circulation of steps S3 to S7 may be stopped when it is determined that the necessary measurements by the instrument 5 have been completed, when the detector 9 detects that the abnormality has been resolved, when a specific time has elapsed since the operator's instruction or the output of an opening operation command signal, etc., and is not limited to this.

[0036] Next, the effects of this embodiment will be described.

[0037] The shielding device 20 for protecting the instrument 5 of the above-mentioned embodiment from radiation comprises an upper lead storage chamber 1 for storing lead pellets 15, an instrument shielding section 4 arranged around the instrument 5, a heat exchanger 7 for cooling the lead pellets 15, a ball lifting machine 8 for supplying the cooled lead pellets 15 to the upper lead storage chamber 1, and a detector 9 for outputting an opening / closing operation command signal for the opening / closing section 2 provided in the upper lead storage chamber 1.

[0038] In this way, the heated lead particles 15 are physically circulated and cooled by the radiation shielding, ensuring shielding performance and preventing overheating of the lead particles 15. Therefore, since the continuity of measurement by the measuring instrument 5 can be improved with a more compact housing compared to the conventional configuration, the housing structure of the shielding device can be made compact so that the measuring instrument can operate normally even in a high-temperature, high-radiation environment, and it can be installed in a limited space in an existing plant. In addition, the shielding device 20 has excellent maintainability and workability.

[0039] Furthermore, since the upper lead storage chamber 1 is positioned vertically above the instrument shielding section 4, lead particles 15 can be supplied to the instrument shielding section 4 by free fall due to gravity, so no driving source for supplying lead to the instrument shielding section 4 is required, making it possible to further miniaturize the device and reduce the labor required.

[0040] Furthermore, since the heat exchanger 7 and the ball lifting machine 8 are arranged vertically below the instrument shielding section 4, a drive mechanism for supplying power to the heat exchanger 7 and the ball lifting machine 8 is not required, which enables further miniaturization and labor saving of the device.

[0041] In addition, the detector 9 outputs an opening command signal to the opening / closing section 2 when it detects an abnormality, thereby preventing the circulation of lead particles 15 at unnecessary times and automatically starting the supply, thereby ensuring that the measurement by the instrument 5 can continue even in the event of a serious accident, etc.

[0042] Furthermore, the instrument shielding section 4 is configured to surround the instrument 5, and lead particles 15 circulate inside it, thereby realizing a configuration in which the cooled lead particles 15 circulate sequentially around the instrument 5 while shielding it from radiation, allowing the instrument 5 to continue measuring stably even when an abnormality occurs.

[0043] In addition, since the heat exchanger 7 cools by directly exchanging heat with the lead pellets 15, the cooling efficiency can be increased and the circulation efficiency of the lead pellets 15 can be improved, which makes it possible to avoid filling the lead pellets 15 with an amount greater than necessary and to achieve miniaturization, etc.

[0044] Furthermore, by further providing piping 3A connecting the opening / closing unit 2 and the instrument shielding unit 4, piping 3B connecting the instrument shielding unit 4 and the heat exchanger 7, and piping 3C, 3D connecting the heat exchanger 7 and the upper lead storage chamber 1, it is possible to maintain an appropriate distance between the opening / closing unit 2 and the instrument shielding unit 4, between the instrument shielding unit 4 and the heat exchanger 7, and between the heat exchanger 7 and the upper lead storage chamber 1, thereby allowing freedom of design and increasing portability.

[0045] <Other> The present invention is not limited to the above-mentioned embodiment, and various modifications and applications are possible. The above-mentioned embodiment has been described in detail to explain the present invention in an easily understandable manner, and the present invention is not necessarily limited to having all of the described configurations. [Explanation of symbols]

[0046] 1. Upper lead storage chamber 2. Opening and closing section 3A…Pipe (first pipe) 3B…Pipe (second pipe) 3C,3D…Piping (3rd piping) 4...Instrument shielding section 5. Instruments 6…Lower lead storage room (supply section) 7...Heat exchanger 8...Dropping machine (supply section) 9…Detector (control unit) 10,11,12...Signal lines 15...lead grains 20...Shielding device

Claims

1. A shielding device for protecting an instrument from radiation, comprising: a storage chamber for storing lead pellets; an instrument shield disposed around the instrument; a heat exchanger for cooling the lead pellets; A supply unit that supplies the cooled lead pellets to the storage chamber; A command unit that outputs an opening / closing operation command signal for an opening / closing unit provided in the storage chamber. Shielding device.

2. 2. The shielding device according to claim 1, The storage chamber is disposed vertically above the instrument shield. Shielding device.

3. 2. The shielding device according to claim 1, The heat exchanger and the supply section are disposed vertically below the instrument shield. Shielding device.

4. 2. The shielding device according to claim 1, The command unit outputs an opening operation command signal to the opening / closing unit when an abnormality is detected. Shielding device.

5. 2. The shielding device according to claim 1, The meter shielding portion is configured to surround the meter, and the lead particles circulate therein. Shielding device.

6. 2. The shielding device according to claim 1, The heat exchanger cools the lead pellets by directly exchanging heat with them. Shielding device.

7. 2. The shielding device according to claim 1, A first pipe connecting the opening / closing unit and the instrument shielding unit; A second pipe connecting the instrument shielding portion and the heat exchanger; Further comprising a third pipe connecting the heat exchanger and the storage chamber. Shielding device.

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