JP7399044B2 - Control rod drives and reactors - Google Patents

Description

The present disclosure relates to control rod drives and nuclear reactors.

A pressurized water reactor (PWR) uses control rods to absorb neutrons generated within the reactor core, thereby adjusting the number of neutrons and controlling the reactor output. Control rods are moved in and out of the reactor core by a control rod drive mechanism (CRDM).

As a control rod drive device for a pressurized water reactor, for example, a magnetic jack shown in Patent Document 1 is generally applied. A magnetic jack uses electromagnetic force to move a latch that intermittently grips the control rod drive shaft (hereinafter simply referred to as the drive shaft) to drive the drive shaft in the axial direction. Housed within the drive housing. The control rod drive device housing includes a drive shaft housing that houses a drive shaft, and a latch housing that supports an electromagnetic coil on the outside and houses a latch inside. The lower end of the latch housing is connected to a nozzle stub that is welded to the inside and outside of the reactor vessel lid.

For example, Patent Document 2 describes a modular nuclear reactor system in which the core, upper reactor internals, steam generator, pressurizer, and inlet and outlet of the primary loop circulation pump are housed in the same reactor vessel. A furnace is shown. In this nuclear reactor, the entire control rod drive is located inside the reactor vessel, immersed in coolant.

Japanese Patent Application Publication No. 10-123276 Patent No. 6422189

By the way, in a control rod drive device disposed outside the reactor vessel, since it is connected to a nozzle stub that penetrates the lid, a pressure boundary for the primary coolant is formed at the welded part of the nozzle stub. Therefore, the integrity of the welded area must be ensured at all times. In the unlikely event that the weld breaks, there is a risk that the primary coolant will leak, and the control rod and drive shaft may fly out of the reactor vessel due to the pressure difference between the inside and outside of the reactor vessel. Therefore, it is necessary to design with these accidents in mind.

The present disclosure solves the above-mentioned problems, and makes it possible to improve the safety of a nuclear reactor vessel without having to design a system that takes into account accidents such as primary coolant leakage or control rods and drive shafts popping out. The purpose is to provide control rod drives and nuclear reactors.

In order to achieve the above object, a control rod drive device according to one aspect of the present disclosure includes a drive motor, a gear driven by the drive motor, and a control rod drive device that is provided to be movable up and down by the drive of the gear and installed in a reactor core. A drive shaft to which a control rod that can be taken in and out is connected, and an electromagnetic clutch that connects or disconnects transmission of driving force from the drive motor to the drive shaft, and all of the above components are arranged inside the reactor vessel. has been done.

In order to achieve the above object, a nuclear reactor according to one aspect of the present disclosure includes the control rod drive device, a reactor core controlled by the control rod drive device, and a reactor core controlled by the control rod drive device and the core. A reactor vessel to be placed.

According to the present disclosure, the safety of a nuclear reactor vessel can be improved.

FIG. 1 is a schematic diagram showing a nuclear reactor according to an embodiment. FIG. 2 is a schematic side view showing the control rod drive device of the embodiment. FIG. 3 is a partially enlarged sectional view showing the control rod drive device of the embodiment. FIG. 4 is a schematic perspective view showing a cable of an electromagnetic coil in the control rod drive device of the embodiment. FIG. 5 is a perspective view showing the control rod drive device of the embodiment. FIG. 6 is a bottom view showing the control rod drive device of the embodiment. FIG. 7 is a schematic diagram showing a typical nuclear reactor.

Embodiments according to the present disclosure will be described in detail below based on the drawings. Note that the present invention is not limited to this embodiment. Furthermore, the constituent elements in the embodiments described below include those that can be easily replaced by those skilled in the art, or those that are substantially the same.

FIG. 1 is a schematic diagram showing a nuclear reactor according to an embodiment.

A nuclear reactor 100 shown in FIG. 1 is a pressurized water reactor used in a pressurized water nuclear power plant. In a pressurized water nuclear power plant, light water, which is a primary coolant, is heated in a nuclear reactor 100, and then the heated primary coolant is sent to a steam generator (not shown). In a nuclear power plant, the high temperature primary coolant is exchanged with the secondary coolant in the steam generator to evaporate the secondary coolant, and the steam from the evaporated secondary coolant is sent to the turbine. Electricity is generated by sending energy to drive a generator. Furthermore, the high temperature primary coolant that has flowed into the steam generator is cooled by exchanging heat with the secondary coolant, returned to the nuclear reactor 100, and heated to a high temperature again. On the other hand, the steam of the secondary coolant used in the turbine for power generation is cooled in the condenser, returned to liquid, and returned to the steam generator via the condensate water pipe, where it is re-steamed by heat exchange with the primary coolant. becomes.

The nuclear reactor 100 has a reactor vessel 101 that is a pressure vessel. In the reactor vessel 101, a reactor vessel lid 101B is fixed to a reactor vessel main body 101A with a plurality of stud bolts and nuts. The reactor vessel main body 101A includes an outlet nozzle 101Aa that sends the primary coolant to the steam generator, and an inlet nozzle 101Ab that returns the primary coolant that has been cooled by exchanging heat with the secondary coolant in the steam generator. It is provided. A control rod drive device 1 and a fuel assembly 102 are housed inside this reactor vessel 101 . The details of the control rod drive device 1 will be described later, but it is arranged inside and above the reactor vessel 101. The fuel assembly 102 is a nuclear fuel material and is arranged in a reactor core 103 provided on the lower side inside the reactor vessel 101 . Although not shown, the fuel assembly 102 has a vertically elongated structure in which a large number of fuel rods are bundled in a lattice shape by a support lattice. A large number of fuel assemblies 102 are arranged with their upper ends facing upward and their lower ends facing downward with respect to the reactor core 103 . Furthermore, control rods 104 are arranged inside the reactor core 103 . The control rods 104 are inserted into and removed from the interior of the multiple fuel assemblies 102 from above. The control rods 104 are made of a control material that absorbs neutrons, and are inserted into the fuel assembly 102 to absorb neutrons associated with the fission reaction of the nuclear fuel material in the fuel assembly 102 and prevent it from becoming critical. can be controlled. On the other hand, by removing the control rods 104 from inside the fuel assembly 102, the number of neutrons in the reactor 100 can be increased, and the reaction can be increased from critical to rated power. Further, inside the reactor vessel 101, between the reactor core 103 and the control rod drive device 1, a large number of control rod guide tubes 105 are arranged to guide the control rods 104 in ascending and descending directions.

FIG. 2 is a schematic side view showing the control rod drive device of the embodiment. FIG. 3 is a partially enlarged sectional view showing the control rod drive device of the embodiment. FIG. 4 is a schematic perspective view showing a cable of an electromagnetic coil in the control rod drive device of the embodiment. FIG. 5 is a perspective view showing the control rod drive device of the embodiment. FIG. 6 is a bottom view showing the control rod drive device of the embodiment.

The control rod drive device 1 is housed inside the reactor vessel 101 as described above. The control rod drive device 1 controls the insertion and removal of the control rods 104 into and out of the fuel assembly 102 by moving the control rods 104 in the vertical direction. The control rod drive device 1 includes a drive motor 2, an electromagnetic clutch 3, a gear group 4, a drive shaft 5, and a biasing means 6.

The drive motor 2 is arranged at the upper side of the control rod drive device 1, as shown in FIG. As shown in FIG. 3, the drive motor 2 includes a rotor 2A and a stator 2B.

The rotor 2A is provided to extend in the vertical direction on a central axis CL that extends in the vertical direction. The vertical direction in which the central axis CL extends is also referred to as the axial direction. The rotor 2A is rotatably provided around a central axis CL with respect to a case 7 that accommodates the drive motor 2, the electromagnetic clutch 3, and the gear group 4. The rotor 2A is made of magnetic material. The rotor 2A has salient poles 2Aa. The salient poles 2Aa are protrusions extending inward in the radial direction away from the central axis CL in the rotor 2A, and a plurality of salient poles 2Aa are provided at intervals in the circumferential direction around the central axis CL. Further, the rotor 2A has a hollow portion 2Ab formed therein, which is a through hole penetrating in the axial direction on the central axis CL.

The stator 2B is formed into a cylindrical shape centered on the central axis CL so as to surround the rotor 2A. Stator 2B is made of magnetic material. The stator 2B has a plurality of core portions 2Ba that extend radially inward toward the center axis CL, face the rotor 2A, and are provided at intervals in the circumferential direction around the center axis CL. In the stator 2B, an electromagnetic coil 2C is wound around each core portion 2Ba with an insulating material (not shown) interposed therebetween. Further, in the stator 2B, the electromagnetic coil 2C is constituted by an inorganic insulated cable 8 shown in FIG.

The inorganic insulated cable 8 has a core wire 8a surrounded by a metal sheath 8b, and an inorganic insulator 8c such as magnesium oxide is filled between the core wire 8a and the metal sheath 8b, and is called an MI cable (Mineral Insulated Cable). ) Also called. In the present embodiment, the inorganic insulated cable 8 has a metal sheath 8b made of a heat-resistant and corrosion-resistant alloy having excellent heat resistance and corrosion resistance, such as Inconel 690 (registered trademark).

In this drive motor 2, the salient poles 2Aa of the rotor 2A are attracted by the attractive force of the magnetic field generated by passing a current through the electromagnetic coil 2C of the stator 2B, and the rotor 2A rotates around the central axis CL. That is, the drive motor 2 constitutes a reluctance motor that rotates the rotor 2A made of a magnetic material by the attractive force of the magnetic field generated in the electromagnetic coil 2C of the stator 2B without using a permanent magnet.

As shown in FIG. 3, the electromagnetic clutch 3 includes a first magnetic pole 3A, a second magnetic pole 3B, and an electromagnetic coil 3C.

The first magnetic pole 3A is made of a magnetic material and is fixed to the rotor 2A of the drive motor 2. Therefore, the first magnetic pole 3A rotates as the rotor 2A of the drive motor 2 rotates. The first magnetic pole 3A has an adsorption portion 3Aa formed at its lower end in the axial direction that projects outward in the radial direction and has a flat lower end surface.

The second magnetic pole 3B is made of a magnetic material, can be magnetically attached to the first magnetic pole 3A, and is provided so as to be movable in the axial direction with respect to the case 7. Further, the second magnetic pole 3B is provided to be rotatable about the central axis CL with respect to the case 7. The second magnetic pole 3B has an adsorption portion 3Ba formed at its upper end in the axial direction that protrudes outward in the radial direction and has a flat upper end surface. The suction portion 3Ba is provided so that its upper end surface faces the lower end surface of the suction portion 3Aa of the first magnetic pole 3A. The second magnetic pole 3B is connected to the gear group 4 at its lower end.

The first magnetic pole 3A and the second magnetic pole 3B have a hollow portion 3D formed therein, which is a through hole that penetrates in the axial direction on the central axis CL. The hollow part 3D is formed to have the same inner diameter as the hollow part 2Ab formed in the rotor 2A of the drive motor 2, and communicates with the hollow part 2Ab.

The electromagnetic coil 3C is fixed to the case 7 and is provided to generate a magnetic field in the axial direction between the first magnetic pole 3A and the second magnetic pole 3B. The electromagnetic coil 3C is composed of an inorganic insulated cable 8 shown in FIG.

In this electromagnetic clutch 3, a magnetic field is generated in the axial direction by passing a current through the electromagnetic coil 3C, which acts on the attraction portion 3Aa of the first magnetic pole 3A and the attraction portion 3Ba of the second magnetic pole 3B. When a magnetic field acts on the attracting portion 3Aa and the attracting portion 3Ba, an attractive force that attracts them to each other is generated, and the second magnetic pole 3B is attracted to the first magnetic pole 3A and attracted thereto. When the second magnetic pole 3B is attracted to the first magnetic pole 3A, the rotation of the drive motor 2 is transmitted to the gear group 4 via the first magnetic pole 3A and the second magnetic pole 3B. On the other hand, in the electromagnetic clutch 3, if no current is passed through the electromagnetic coil 3C, the magnetic field does not act on the attraction part 3Aa of the first magnetic pole 3A and the attraction part 3Ba of the second magnetic pole 3B, and the first magnetic pole 3A and the second magnetic pole The adsorption with 3B is released. When the attraction between the first magnetic pole 3A and the second magnetic pole 3B is released, the rotation of the drive motor 2 is no longer transmitted to the gear group 4, and the gear group 4 becomes free.

The gear group 4 is driven by the drive motor 2 in a state where the electromagnetic clutch 3 is engaged, and raises and lowers the drive shaft 5. As shown in FIGS. 5 and 6, the gear group 4 includes a first gear 4A, a second gear 4B, a third gear 4C, a fourth gear 4D, a fifth gear 4E, and a rack tooth 4F. has.

The first gear 4A is formed on the first rotating shaft 4G. The first rotating shaft 4G is provided to extend in the axial direction on the central axis CL, and is fixed to the lower end of the second magnetic pole 3B of the electromagnetic clutch 3. Therefore, the rotation around the center axis CL of the drive motor 2 is transmitted to the first rotation shaft 4G. The first rotating shaft 4G has a hollow portion 4H formed of a through hole that penetrates in the axial direction on the central axis CL. The hollow part 4H is formed to have the same inner diameter as the hollow part 3D formed in the first magnetic pole 3A and the second magnetic pole 3B of the electromagnetic clutch 3, and communicates with the hollow part 3D. The first gear 4A is formed with a plurality of meshing teeth arranged at a predetermined pitch in the circumferential direction on the outer circumference of the first rotating shaft 4G.

The second gear 4B is formed on the second rotating shaft 4I. The second rotating shaft 4I is provided to extend in the axial direction parallel to the central axis CL, and is arranged to be rotatable with respect to the case 7 around the central axis parallel to the central axis CL. The second gear 4B is formed with a plurality of meshing teeth arranged at a predetermined pitch in the circumferential direction on the outer periphery of the upper end of the second rotating shaft 4I. The second gear 4B is provided to mesh with the first gear 4A. Therefore, the rotation of the first rotation shaft 4G about the central axis CL is transmitted to the second rotation shaft 4I through the meshing of the first gear 4A and the second gear 4B.

The third gear 4C is formed by a plurality of meshing teeth arranged at a predetermined pitch in the circumferential direction on the outer periphery of the lower end of the second rotating shaft 4I. Therefore, the third gear 4C rotates with the rotation of the second rotating shaft 4I.

The fourth gear 4D is formed on the third rotating shaft 4J. The third rotating shaft 4J is provided to extend in a direction perpendicular to the central axis CL, and is arranged to be rotatable about the central axis perpendicular to the central axis CL with respect to the case 7. The third rotating shaft 4J has a disk-shaped disk portion 4Ja fixed to its one end side, and the fourth gear 4D is fixed to one end of the third rotation shaft 4J. A plurality of meshing teeth are arranged at a predetermined pitch in the circumferential direction of the disc portion 4Ja along the periphery. The fourth gear 4D is provided to mesh with the third gear 4C. Therefore, the rotation of the second rotation shaft 4I is transmitted to the third rotation shaft 4J through the meshing of the third gear 4C and the fourth gear 4D.

The fifth gear 4E is formed on the third rotating shaft 4J. The fifth gear 4E is formed with a plurality of meshing teeth arranged at a predetermined pitch in the circumferential direction of the third rotating shaft 4J on the outer peripheral portion of the other end side of the third rotating shaft 4J. Therefore, the fifth gear 4E rotates with the rotation of the third rotating shaft 4J.

Rack teeth 4F are formed on the drive shaft 5. The drive shaft 5 is provided so as to be movable up and down in the axial direction on the central axis CL with respect to the case 7 . When the drive shaft 5 moves up and down, it moves through a hollow part 4H formed in the first rotating shaft, a hollow part 3D formed in the first magnetic pole 3A and second magnetic pole 3B of the electromagnetic clutch 3, and a hollow part formed in the rotor 2A. 2Ab is inserted. Further, the drive shaft 5 is also inserted through the control rod guide tube 105. The rack teeth 4F are formed by a plurality of meshing teeth arranged at a predetermined pitch in the axial direction on the outer circumference of the drive shaft 5. The rack teeth 4F are provided to mesh with the fifth gear 4E. The fifth gear 4E constitutes pinion teeth that mesh with the rack teeth 4F. Therefore, the rotation of the third rotation shaft 4J is transmitted to the drive shaft 5 through the meshing of the fifth gear 4E and the rack teeth 4F. The drive shaft 5 moves up and down based on the direction in which the third rotation shaft 4J rotates due to the engagement between the fifth gear 4E and the rack teeth 4F. A control rod 104 is connected to the drive shaft 5 at its lower end.

Therefore, the gear group 4 is attracted by the electromagnetic clutch 3 and connected to transmit the driving force from the drive motor 2, and rotation in one direction is transmitted by the drive motor 2, and the drive shaft 5 (control rod 104) to rise. Further, the gear group 4 is connected to the electromagnetic clutch 3 to which the driving force is transmitted from the drive motor 2, and rotation in the other direction is transmitted by the drive motor 2, and the drive shaft 5 (control rod 104) is connected to the gear group 4. lower. In addition, when the electromagnetic clutch 3 is attracted and the gear group 4 is connected to the drive motor 2, the drive shaft 5 (control rod 104) is raised or lowered to a predetermined position when the drive motor 2 is not driven. It is held at In addition, in the gear group 4, the transmission of driving force from the drive motor 2 is cut off when the electromagnetic clutch 3 is released from attraction, so that the rotation shafts 4G, 4I, and 4J are free to rotate, and the drive shaft 5 is free to rotate. Free descent is allowed, and control rod 104 with drive shaft 5 is allowed to fall freely. Therefore, by disengaging the electromagnetic clutch 3, the scram operation in which the control rod 104 freely falls is compensated for, and the nuclear fission reaction of the nuclear fuel material inserted into the fuel assembly 102 is suppressed and the nuclear fuel material in the fuel assembly 102 reaches a critical state. control so that it does not become

As shown in FIG. 2, the biasing means 6 is provided in the control rod guide tube 105 in this embodiment. The biasing means 6 is provided inside the control rod guide tube 105 and constitutes a compression spring that always biases the drive shaft 5 inserted through the control rod guide tube 105 downward toward the reactor core 103 side. The biasing means 6, which is a compression spring, has an upper end caught on an upper end engaging portion 105a inside the control rod guide tube 105, and a lower end caught on an engaging portion 5a of the drive shaft 5 inside the control rod guide tube 105. It is provided. Therefore, the biasing means 6 assists the free descent of the drive shaft 5 by cutting off the transmission of the driving force from the drive motor 2 when the electromagnetic clutch 3 is released from attraction, and the biasing means 6 assists the free descent of the drive shaft 5. Assists control rod 104 in free fall. When the electromagnetic clutch 3 is released from attraction, a load is generated in the meshing of the gear group 4, but the biasing means 6 resists this load and supports the free descent of the drive shaft 5. Assists control rod 104 in free fall. The action of the biasing means 6 ensures that the control rods 104 are inserted into the fuel assembly 102 even in the event of tilting, rocking, or overturning of the reactor (ship) when assuming a nuclear reactor for a marine reactor. Responsible for the function of

In this way, the control rod drive device 1 of the present embodiment is equipped with a drive motor 2, a gear (fifth gear 4E of gear group 4) driven by the drive motor 2, and a gear that can be moved up and down by driving the gear. A drive shaft 5 to which a control rod 104 that can be taken in and out of the reactor core 103 is connected, and an electromagnetic clutch 3 that connects or disconnects the transmission of driving force from the drive motor 2 to the drive shaft 5, and all of the above configurations ( A drive motor 2, a gear group 4, a drive shaft 5, an electromagnetic clutch 3, a reactor core 103, and a control rod 104) are arranged inside the reactor vessel 101.

According to this control rod drive device 1, the drive motor 2, the gear (the fifth gear 4E of the gear group 4), the drive shaft 5, and the electromagnetic clutch 3 are arranged inside the reactor vessel 101. Therefore, there is no configuration for driving the control rods 104 outside the reactor vessel 101. That is, the control rod drive device 1 of this embodiment eliminates the need for a nozzle that penetrates from the inside of the reactor vessel 101 to the outside. Therefore, by applying the control rod drive device 1 of this embodiment, the nozzle There is no need to design with the assumption that welds will break. As a result, according to the control rod drive device 1 of this embodiment, the safety of the reactor vessel 101 can be improved.

Here, in a control rod drive device 1001 disposed outside the reactor vessel 1101 via a nozzle 1106, as in a general nuclear reactor 1000 illustrated in FIG. Since the control rods are moved in and out of the reactor core inside the reactor vessel 1101 by the shaft, the length of the drive shaft becomes long, so the case 1009 through which the drive rods are inserted into the outside of the reactor vessel 1101 is extended upward. It will be established. The total height of the reactor vessel 1101 including the control rod drive device 1001 and the case 1009 is La. On the other hand, when the control rod drive device 1 of this embodiment is applied, the drive motor 2, the gear (the fifth gear 4E of the gear group 4), the drive shaft 5, and the electromagnetic clutch 3 are connected to the inside of the reactor vessel 101. As shown in FIG. 1, when the inner diameter Db is equal to the inner diameter Da of the reactor 1000, the overall height Lb of the reactor vessel 101 is , is lower than the overall height La of the reactor vessel 1101. As a result, according to the control rod drive device 1 of this embodiment, the size of the reactor vessel 101 can be reduced.

In the control rod drive device 1 of the present embodiment, the gear (the fifth gear 4E of the gear group 4) is connected to the drive shaft 5 such that the fifth gear 4E, which is a pinion tooth, is connected to the rack tooth 4F of the drive shaft 5. Depends on the mesh. The control rod drive device 1 of this embodiment drives the drive shaft 5 up and down by such simple engagement of rack and pinions. As a result, according to the control rod drive device 1 of this embodiment, the control rods 104 can be reliably driven in a high temperature and underwater environment with a simple configuration with few failures.

Further, in the control rod drive device 1 of the present embodiment, the electromagnetic clutch 3 connects or disconnects the transmission of the driving force from the drive motor 2 to the drive shaft 5. By cutting off the transmission, the drive shaft 5 can be freely lowered through the gear, and the control rod 104 can be freely dropped together with the drive shaft 5. Therefore, according to the control rod drive device 1 of the present embodiment, by disengaging the electromagnetic clutch 3, the control rods 104 fall freely and are inserted into the fuel assembly 102. It is possible to suppress the fission reaction of nuclear fuel materials and control them so that they do not reach a critical state.

Moreover, in the control rod drive device 1 of this embodiment, the drive motor 2 rotates the rotor 2A made of a magnetic material by the attraction force of the magnetic field generated in the electromagnetic coil 2C of the stator 2B.

According to this control rod drive device 1, the drive motor 2 can constitute a reluctance motor that does not use a permanent magnet. Permanent magnets have low heat resistance and are difficult to use inside the reactor vessel 101 where the temperature is 350° C. or higher. As a result, according to the control rod drive device 1 of this embodiment, placement inside the high-temperature reactor vessel 101 can be realized.

Further, in the control rod drive device 1 of this embodiment, the cables of the electromagnetic coils 2C and 3C of the drive motor 2 and the electromagnetic clutch 3 are made of an inorganic insulated cable 8.

According to this control rod drive device 1, by using the inorganic insulated cable 8, the functions of the electromagnetic coils 2C and 3C can be maintained even when water floods into the stator 2B.

Furthermore, in the control rod drive device 1 of this embodiment, the metal sheath 8b of the inorganic insulated cable 8 is made of a heat-resistant and corrosion-resistant alloy.

According to this control rod drive device 1, by using a heat-resistant and corrosion-resistant alloy for the metal sheath 8b of the inorganic insulated cable 8, heat resistance is improved and the functions of the electromagnetic coils 2C and 3C can be maintained in a high-temperature environment.

In addition, in the control rod drive device 1 of this embodiment, hollow portions 2Ab, 3D, and 4H are formed that penetrate in the axial direction on the central axis CL of the rotor 2A of the drive motor 2, and the hollow portions 2Ab, 3D, and 4H are driven. The shaft 5 is inserted.

According to this control rod drive device 1, the drive shaft 5 can be arranged on the central axis CL of the rotor 2A of the drive motor 2, and the device can be downsized.

Furthermore, the control rod drive device 1 of this embodiment includes a biasing means 6 that always biases the drive shaft 5 toward the reactor core 103 side.

According to this control rod drive device 1, when the electromagnetic clutch 3 is released from adsorption, a load is generated due to meshing of the gears, but the biasing means 6 resists this load and assists the drive shaft 5 to freely descend. However, the free fall of the control rod 104 along with the drive shaft 5 can be assisted. As a result, according to the control rod drive device 1 of this embodiment, the nuclear fission reaction of the nuclear fuel material in the fuel assembly 102 can be reliably suppressed and safely controlled so as not to reach a critical state. The action of the biasing means 6 ensures that the control rods 104 are inserted into the fuel assembly 102 even in the event of tilting, rocking, or overturning of the reactor (ship) when assuming a nuclear reactor for a marine reactor. Responsible for the function of

Moreover, the nuclear reactor 100 of this embodiment has the control rod drive device 1 of this embodiment described above, a reactor core 103 controlled by the control rod drive device 1, and the control rod drive device 1 and the reactor core 103 disposed inside. A reactor vessel 101 is provided.

According to this reactor vessel 101, the safety of the reactor vessel 101 can be improved, the reactor vessel 101 can be made smaller, the control rods 104 can be reliably driven in high-temperature and underwater environments, and the safety of the reactor vessel 101 can be improved. control.

1 Control rod drive device 2 Drive motor 2A Rotor 2Ab Hollow part 2B Stator 2C Electromagnetic coil 3 Electromagnetic clutch 3C Electromagnetic coil 3D Hollow part 4 Gear group 4E Fifth gear 4F Rack teeth 5 Drive shaft 6 Biasing means 8 Inorganic insulated cable 8b Metal Sheath 100 Reactor 101 Reactor vessel 103 Core 104 Control rod

Claims (7)

a drive motor;
a gear driven by the drive motor;
a drive shaft that is connected to a control rod that can be moved up and down by the drive of the gear and that can be taken in and out of the reactor core;
an electromagnetic clutch that connects or disconnects transmission of driving force from the drive motor to the drive shaft;
The drive motor, the gear, the drive shaft, and the electromagnetic clutch are arranged inside a reactor vessel, and the reactor vessel is provided with a reactor vessel lid on an upper part of the reactor vessel body. A control rod drive device in which a portion of the reactor vessel lid is exposed from the reactor vessel body when the reactor vessel lid is removed from the reactor vessel body . The control rod drive device according to claim 1, wherein the drive motor rotates a rotor made of a magnetic material by the attraction force of a magnetic field generated in an electromagnetic coil of a stator. 3. The control rod drive device according to claim 1, wherein a cable of an electromagnetic coil of the drive motor and the electromagnetic clutch is made of an inorganic insulated cable. The control rod drive device according to claim 3, wherein the metal sheath of the inorganic insulated cable is made of a heat-resistant and corrosion-resistant alloy. The control rod drive device according to any one of claims 1 to 4, wherein a hollow portion is formed on the central axis of the rotor of the drive motor and penetrates in the axial direction, and the drive shaft is inserted into the hollow portion. . The control rod drive device according to any one of claims 1 to 5, further comprising a biasing means that always biases the drive shaft toward the reactor core. A control rod drive device according to any one of claims 1 to 6,
a reactor core controlled by the control rod drive device;
a nuclear reactor vessel disposed inside the control rod drive device and the reactor core;
A nuclear reactor equipped with

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