Nuclear reactor control rod drive device

Abstract

A reactor control rod drive device according to the present invention is characterized by comprising: a plurality of control rod guide tubes installed between a plurality of nuclear fuel rods and having a control rod inserted therein; a control rod cylinder coupled to the upper part of the control rod guide tubes; a pipe connecting the control rod cylinder to the reactor side wall to guide an operating fluid flowing in from outside the reactor into the control rod cylinder; and a control rod piston coupled to the upper part of the control rod and configured to move in an up-and-down direction by the pressure of the operating fluid.

Description

Technology Field

[0001] The present invention relates to a device for controlling the operation of a control rod installed for controlling a nuclear reactor to be withdrawn or inserted from the core. Background Technology

[0002] A reactor control system is required for the smooth operation of the reactor. The configuration of the control system varies depending on the reactor type; in most types, mechanical control rods are used as the primary method, with additional nuclear reactivity control devices employed in addition.

[0003] In the case of pressurized water reactors, a combination of controlling nuclear reactions by inserting mechanical control rods into the reactor core and controlling nuclear reactions by adding boric acid solution to the coolant is used. Control rods are used to control local and immediate reactor reactions, while boric acid solution is used to control the reactor's average nuclear reactions. In the event of an emergency shutdown of the reactor, all control rods are inserted and high-concentration boric acid solution is injected to stop the nuclear reactions.

[0004] In the case of boiling water reactors, nuclear reactions are controlled solely by mechanical control rods. Since nuclear reactivity converges according to the boiling temperature of the coolant in boiling water reactors, control rods are inserted or withdrawn to regulate nuclear reactivity if the reactor deviates excessively from this temperature.

[0005] FIG. 1 is a perspective view and cross-sectional view of a conventional pressurized water reactor, FIG. 2 is a perspective view and cross-sectional view (A-A') of a conventional nuclear fuel assembly, FIG. 3 is a horizontal cross-sectional view and partial enlarged view of a conventional reactor core, and FIG. 4 is a perspective view of a conventional control rod assembly.

[0006] First, as illustrated in FIG. 1, most pressurized water reactors, including the Korean-type new pressurized water reactor APR1400, have a control rod protection tube (40) installed on the upper part of the core (30) where nuclear fuel is installed, and a control rod drive device (50) installed on the upper part of the reactor cover (20). As the control rod drive device (50) operates electrically, heat is generated, and a cooling device (not shown) for cooling the heat is installed on top of it.

[0007] Additionally, as illustrated in FIG. 2, in the case of a conventional nuclear fuel assembly, a plurality of control rod guide tubes (70) are formed so that control rods are inserted into the nuclear fuel assembly (60), and the number and diameter of the control rod guide tubes (70) vary depending on the nuclear fuel used in the reactor. In the case of FIG. 2, it is shown that control rod guide tubes (70) are formed to insert four control rods.

[0008] Next, as shown in FIG. 3, the white circle (A) shown in the horizontal cross-section of the reactor core is the location where the control rods are inserted. The control rods are not controlled individually, but rather the reactor is controlled by inserting or withdrawing multiple rods into or from the core simultaneously.

[0009] In the case of FIG. 3, a bundle of four control rods (4-element control rod assembly, 80) and a bundle of twelve control rods (12-element control rod assembly, 90) are shown.

[0010] FIG. 4 illustrates a 4-element control rod assembly (80) and a 12-element control rod assembly (90), and the method of binding the control rods as described above may vary depending on the reactor type.

[0011] As mentioned above, the method of bundling multiple control rods to simultaneously insert or withdraw them from the reactor has the disadvantage of causing significant changes in the local nuclear reactivity of the reactor.

[0012] In addition, as multiple control rods are bundled together and their weight increases, the actuator must operate with greater force, which consequently leads to a larger structure for the control rod actuator. When control rods are grouped in this way, it becomes difficult to control the nuclear reactivity of the entire core evenly and gradually using only the control rods; instead, boric acid is mixed into the reactor coolant and its concentration is adjusted to control the average nuclear reactivity of the reactor.

[0013] The control rod actuator (CRDM) is installed on top of the reactor cover, which results in the disadvantage of significantly increasing the height of the reactor. Consequently, this structural configuration is vulnerable to seismic loads, adding substantial dynamic loads to the reactor system in the event of an earthquake. Prior art literature

[0015] Republic of Korea, Registered Patent Publication, No. 10-2187262 (2020.11.30) The problem to be solved

[0016] The present invention was devised to solve the aforementioned problems. By improving the existing mechanical control rod structure and introducing a hydraulic cylinder-type single control rod system, the control rods can be controlled individually to finely adjust the reactor's output control, maintain the nuclear reactivity of the reactor core in an optimal state, and increase the combustion rate of nuclear fuel to maximize its utilization. This provides the effect of enabling the reactor's output control to be finely adjusted, maintaining the nuclear reactivity of the reactor core in an optimal state, and maximizing the utilization of nuclear fuel.

[0017] In addition, while conventional large nuclear power plants apply a centralized control system that bundles multiple control rods into the reactor core for insertion or withdrawal, the present invention applies a distributed control system that individually inserts or withdraws control rods into the reactor core, thereby enabling optimal control of the core nuclear reactivity. One of these effects is the ability to operate without boric acid, which eliminates the need for additional systems related to the injection and removal of boric acid solution, thereby providing the effect of simplifying the reactor control system.

[0018] Since the hydraulic cylinder-based control system controls a single control rod, it handles a relatively small weight, eliminating the need for significant force to operate the cylinder. Additionally, because the control circuit can be installed separately from the reactor, the weight of the control system is not transferred to the reactor.

[0019] The total mass of the reactor can be reduced by not installing the control system, including control devices and control circuits, in the reactor cover. As a result, in the event of an earthquake near the nuclear power plant, the seismic load acting on the reactor is reduced, and the seismic load transmitted to the nuclear fuel is also reduced. This provides the same effect as increasing the seismic strength of the nuclear fuel assemblies in the reactor core. means of solving the problem

[0021] A reactor control rod drive device according to the present invention is characterized by comprising: a plurality of control rod guide tubes installed between a plurality of nuclear fuel rods and having a control rod inserted therein; a control rod cylinder coupled to the upper part of the control rod guide tubes; a pipe connecting the control rod cylinder to the reactor side wall to guide an operating fluid flowing in from outside the reactor into the control rod cylinder; and a control rod piston coupled to the upper part of the control rod and configured to move in an up-and-down direction by the pressure of the operating fluid.

[0022] In addition, preferably, it further includes a coaxial cable installed along the inside of the pipe and a quick connector coupled to the end of the coaxial cable and provided inside the control rod cylinder, and is characterized in that a space is formed on the upper surface of the control rod piston so as to insert and connect the quick connector.

[0023] Additionally, preferably, the system further includes a control rod position measuring system located outside the reactor and controlling the forward and backward movement of the coaxial cable, wherein the control rod position measuring system comprises a housing, a pulley located inside the housing on which the coaxial cable is wound, a magnet receiving groove provided on the upper part of the pulley, a pulley shaft having a guide tube formed therein to guide the end of the coaxial cable wound on the pulley toward the magnet receiving groove, a permanent magnet inserted into the magnet receiving groove and to which the end of the coaxial cable is connected and fixed, and a solenoid electromagnet coupled to the upper side of the housing.

[0024] Additionally, preferably, the control rod position measuring system further comprises a magnet receiving groove provided at the bottom of the pulley, an encoder magnet inserted into the magnet receiving groove at the bottom, a mainspring provided along the lower outer surface of the pulley with both ends connected to the pulley and the housing, respectively, and an encoder connected to the bottom of the housing to measure the rotation of the encoder magnet, thereby measuring the position of the control rod according to the forward and backward movement of the coaxial cable.

[0025] Additionally, preferably, the system further includes an external pipe connected to the downstream end of the pipe, and on one side of the external pipe, a pipe purging system is provided, comprising a steam collection unit having an internal space for collecting the steam-state working fluid formed in the pipe for removing the steam-state working fluid formed in the pipe, a purge pipe connecting the steam collection unit to a reactor coolant high-pressure storage tank, and a purge valve formed on one side of the purge pipe.

[0026] Additionally, preferably, the system further includes a control rod drive system located outside the reactor and controlling the insertion or withdrawal position of a control rod piston by supplying a working fluid, wherein the control rod drive system comprises: a first working fluid supply pipe formed at the downstream end of the pipe and supplying a working fluid within a reactor coolant high-pressure storage tank to the pipe; a drive pump provided on one side of the first working fluid supply pipe; a first working fluid high-pressure tank that supplies a working fluid to the drive pump; a first injection pump provided between the first working fluid high-pressure tank and the reactor coolant high-pressure storage tank and discharges a working fluid supplied from the reactor coolant high-pressure storage tank toward the first working fluid high-pressure tank; a first shut-off valve provided at the downstream end of the first metering pump; and a first supply valve provided at the upstream end of the first injection pump.

[0027] Additionally, preferably, the system further includes a reactor emergency shutdown system that stops the reactor by supplying a working fluid at high pressure and inserting control rods into the core during abnormal operation of the reactor, wherein the reactor emergency shutdown system comprises: a second working fluid supply pipe formed at the downstream end of the pipe and supplying a working fluid from a reactor coolant high-pressure storage tank to the pipe during abnormal operation of the reactor; a second working fluid high-pressure tank provided on one side of the second working fluid supply pipe; a second injection pump provided between the second working fluid high-pressure tank and the reactor coolant high-pressure storage tank and discharging a working fluid supplied from the reactor coolant high-pressure storage tank toward the second working fluid high-pressure tank; a second shut-off valve provided at the downstream end of the second working fluid high-pressure tank; and a second supply valve provided at the upstream end of the second injection pump.

[0028] In addition, preferably, for simultaneously connecting the plurality of pipes with an external pipe, the multi-connector is further provided between the pipe and the external pipe, and the multi-connector is characterized by comprising a multi-connector nozzle provided at the end of the plurality of pipes, a multi-connector adapter provided at the end of the plurality of external pipes and coupled to one side of the multi-connector nozzle, and a socket provided at the coupling portion of the multi-connector nozzle and the multi-connector adapter.

[0029] Additionally, preferably, for measuring the position of the control rod, it further comprises a coil wound on the outer surface of the control rod cylinder and a linear potentiometer coupled along the outer surface of the coil, or a distance measuring sensor disposed on the upper side of the control rod cylinder. Effects of the invention

[0031] The present invention relates to a method for controlling control rods inserted into or withdrawn from a reactor core. Instead of a conventional method of controlling multiple control rods as a group, the invention relates to a method of controlling them individually. By allowing the control rods to be inserted or withdrawn by the pressure of an operating fluid within a control rod cylinder and enabling the independent control of multiple control rods, the invention provides the effect of maintaining the nuclear reactivity of the reactor core in an optimal state and maximizing the burnup of the nuclear fuel.

[0032] In addition, by making the cross-section of each control rod smaller, the nuclear reactivity of individual control rods is lowered and they are controlled independently, enabling distributed control, which allows for boric acid-free operation. This eliminates the need for additional systems related to boric acid injection and removal, thereby providing the effect of reducing related installation and operating costs.

[0033] In addition, the control circuit is configured to be connected through nozzles formed on the sidewalls of the reactor, thereby separating the control system from the reactor and preventing the weight of the control system from being transferred to the reactor. This reduces the overall mass of the reactor, lowers the height of the reactor, and lowers the position of the center of gravity. Consequently, the seismic load acting on the reactor is reduced, the seismic load transmitted to the nuclear fuel is reduced, and the seismic strength of the reactor and core fuel is increased. Brief explanation of the drawing

[0035] Figure 1 is a perspective view and a cross-sectional view of a conventional pressurized water reactor. FIG. 2 is a perspective view and a cross-sectional view of a conventional nuclear fuel assembly. Figure 3 is a horizontal cross-sectional view and a partial enlarged view of a conventional reactor core. FIG. 4 is a perspective view of a conventional control rod assembly. FIG. 5 is a perspective view of an example reactor in which a reactor control rod driving device according to the present invention is formed. FIG. 6 is (A) a cross-sectional view and (B) a partial enlarged view of an example reactor in which a reactor control rod driving device according to the present invention is formed. FIG. 7 is an exploded perspective view of an example of a reactor in which a reactor control rod driving device according to the present invention is formed. FIG. 8 is a (A) perspective view and (B) cross-sectional view illustrating the combination of a control rod cylinder housing, a control circuit support ring, and a control rod drive device of a nuclear reactor according to the present invention. FIG. 9 is (A) a perspective view and (B) a cross-sectional view of a reactor control rod drive device according to the present invention. FIG. 10 is a (A) perspective view and (B) cross-sectional view illustrating an example of installing a linear potensiometer in a reactor control rod drive device according to the present invention. FIG. 11 is a (A) perspective view and (B) cross-sectional view illustrating an example of installing a distance measuring sensor in a reactor control rod drive device according to the present invention. FIG. 12 is an enlarged cross-sectional view illustrating the combined structure of the piping and external piping of FIG. 9. FIG. 13 is a conceptual diagram illustrating the combination of a quick connector and a control rod piston according to the present invention. FIG. 14 is a configuration diagram of a piping purge system, a control rod driving system, a control rod position measurement system, and a reactor emergency shutdown system according to the present invention. FIG. 15 is a cross-sectional view of a control rod position measuring system according to the present invention. FIG. 16 is a cross-sectional perspective view of a control rod position measuring system according to the present invention. FIG. 17 is a (A) perspective view and (B) cross-sectional view illustrating the combined structure of an external piping and a piping purge system according to the present invention. FIG. 18 is a (A) perspective view and (B) exploded view illustrating the combination of a pipe, an external pipe, and a multi-connector according to the present invention. Specific details for implementing the invention

[0036] Hereinafter, the technical concept of the present invention will be explained in more detail using the attached drawings.

[0037] The attached drawings are merely examples illustrated to further explain the technical concept of the present invention, and therefore the technical concept of the present invention is not limited to the form of the attached drawings.

[0039] The present invention relates to a control rod drive device for controlling the operation of a control rod installed for controlling a nuclear reactor to be withdrawn from or inserted into the core. By improving the existing mechanical control rod structure and introducing a hydraulic cylinder-type single control rod system, the device is configured to enable independent control of multiple control rods.

[0040] FIG. 5 is a perspective view of an example reactor having a reactor control rod drive device formed according to the present invention, FIG. 6 is a cross-sectional view (A) and a partial enlarged view (B) of an example reactor having a reactor control rod drive device formed according to the present invention, FIG. 7 is an exploded perspective view of an example reactor having a reactor control rod drive device formed according to the present invention, and FIG. 8 is a perspective view and a cross-sectional view illustrating the combination of a control rod cylinder housing, a control circuit support ring, and a control rod drive device of a reactor according to the present invention.

[0042] First, as illustrated in FIGS. 5 to 7, the reactor (10) according to the present invention comprises a reactor vessel (100), a steam generator (200), a core shroud (300), a core support barrel (400), a nuclear fuel assembly (500), a control rod cylinder housing (600), a control circuit support ring (700), a reactor cover (800), a cooling water pump (900), and a control rod drive device (1000).

[0043] The reactor vessel (100) has an upper flange formed thereon to facilitate connection with the steam generator (200), control circuit support ring (700), and reactor cover (800), and details will be described later.

[0044] A steam generator (200) is provided inside the reactor vessel (100), and a plurality of steam discharge sections (210) are provided on the upper flange to discharge steam generated inside.

[0045] The core shroud (300) is inserted into the steam generator (200), and a space for installing nuclear fuel is formed inside, and an integrated nuclear fuel assembly (500) is inserted and coupled into the internal space.

[0046] In addition, a neutron reflector (310) is formed to surround the outer surface of the core shroud (300). This is intended to reduce neutron loss from the core, and it is preferable that it be formed of a material having neutron deceleration and reflection properties (such as graphite material).

[0047] The core support barrel (400) is provided above the core shroud (300) and serves to support and protect the core including the nuclear fuel assembly (500).

[0048] The control rod cylinder housing (600) is located on the upper part of the nuclear fuel assembly (500) and accommodates a control rod cylinder (1200), which will be described later, inside.

[0049] More specifically, as illustrated in FIG. 8, the control rod cylinder housing (600) is structured such that a control rod cylinder (1200) is inserted and coupled through a plurality of through holes formed in the upper plate (610) and lower plate (620), respectively, and the control rod cylinder (1200) is fixed by being joined to the upper plate (610) and lower plate (620), respectively, and is supported by a side plate (630) provided between the upper plate (610) and lower plate (620), thereby ensuring structural rigidity and enabling precise alignment with the control rod guide tube (1100).

[0050] In addition, the pipe (1300) connected to the control rod cylinder (1200) is fixed at a predetermined position, thereby providing the effect of stably supporting and aligning the control rod drive device (1000).

[0051] Next, the control circuit support ring (700) is coupled to the upper side of the upper flange of the steam generator (200) and is equipped with a plurality of control circuit ring nozzles (710) to be connected to the piping (1300) of the control rod drive device (1000).

[0052] Here, the control circuit refers to an element for controlling the insertion or withdrawal position of a control rod (1500) and a control rod piston (1400) coupled thereto, including a working fluid and a coaxial cable to be described later.

[0053] The reactor cover (800) is coupled to the upper side of the control circuit support ring (700), and it is preferable that the abutting flange surfaces of the reactor cover (800), the control circuit support ring (700), the upper flange of the steam generator (200), and the upper flange of the reactor vessel (100) are fastened together by stud bolts (B) and nuts (N).

[0054] The cooling water pump (900) is connected to the reactor cover (800) and serves to circulate cooling water to remove heat generated in the reactor.

[0055] Next, the control rod drive device (1000) is coupled to a control rod guide tube (1100) installed between the nuclear fuel assemblies (500) so as to control the withdrawal or insertion position of a plurality of control rods (1500) inserted into the nuclear fuel assembly (500), and details will be described later.

[0057] Hereinafter, a reactor control rod driving device according to the present invention will be described, with reference to FIG. 9.

[0058] FIG. 9 is (A) a perspective view and (B) a cross-sectional view of a reactor control rod drive device according to the present invention.

[0059] As illustrated in (A) of FIG. 9, the reactor control rod drive device (1000) according to the present invention comprises a control rod guide tube (1100), a control rod cylinder (1200), a pipe (1300), and a control rod piston (1400), and the control rod (1500) is inserted into the control rod guide tube (1100) and is then inserted or withdrawn by the pressure of the working fluid in the pipe (1300).

[0060] First, a control rod guide tube (1100) is installed between a plurality of nuclear fuel rods (510), and a control rod (1500) is inserted inside.

[0061] When assembling the reactor, it is preferable that the nuclear fuel assembly (500) be installed in the reactor with the control rod (1500) inserted into the control rod guide tube (1100).

[0062] The control rod cylinder (1200) is coupled to the upper part of the control rod guide tube (1100).

[0063] More specifically, the control rod cylinder (1200) is fixed to the control rod cylinder housing (600) and, during reactor assembly, is aligned with the upper part of the control rod guide tube (1100) and assembled in a contact state.

[0064] The piping (1300) connects the control rod cylinder (1200) and the reactor side wall to guide the working fluid flowing in from outside the reactor into the control rod cylinder (1200).

[0065] In detail, it is preferable that the pipe (1300) connects the control rod cylinder (1200) and the front end of the control circuit ring nozzle (710) of the control circuit support ring (700) to guide the working fluid flowing in through the control circuit ring nozzle (710) into the control rod cylinder (1200).

[0066] At this time, the working fluid is identical to the reactor's coolant and is preferably supplied from a reactor coolant high-pressure storage tank formed outside the reactor.

[0067] Next, the control rod piston (1400) is coupled to the upper part of the control rod (1500) and is configured to be movable in the up and down direction by the pressure of the working fluid.

[0068] In addition, it is desirable to provide a seal ring (1410) on the outer surface of the control rod piston (1400) to prevent leakage of the working fluid.

[0069] This serves to improve the sealing force with the control rod cylinder (1200), thereby enabling the working fluid flowing into the control rod cylinder (1200) to accurately transmit pressure to the control rod piston (1400).

[0070] The above sealing (1410) is formed of a lubricating material and can be implemented in various ways, such as coating or alloy.

[0072] Next, as illustrated in (B) of FIG. 9, the reactor control rod drive device (1000) according to the present invention may further include a coaxial cable (1600) and a quick connector (1700), as shown in FIG. 13.

[0073] FIG. 13 is a conceptual diagram illustrating the combination of a quick connector and a control rod piston according to the present invention, wherein (A) is a conceptual diagram illustrating the state before the combination of the quick connector (1700) and the control rod piston (1400), and (B) is a conceptual diagram illustrating the state after the combination of the quick connector (1700) and the control rod piston (1400), which illustrates the positional change of the locking rod (1730) and the locking ball (1750) to be described later.

[0074] The specific details regarding this are explained in detail below.

[0075] The coaxial cable (1600) is installed along the inside of the pipe (1300), and in detail, it is preferable that it be inserted from outside the reactor through the control circuit ring nozzle (710).

[0076] The quick connector (1700) is coupled to the end of the coaxial cable (1600) and is provided inside the control rod cylinder (1200). Additionally, it is preferable that the quick connector (1700) be provided to be movable in the up and down direction by the pressure of the working fluid.

[0077] In addition, a space (1430) is formed on the upper surface of the control rod piston (1400) so that the quick connector (1700) can be inserted and coupled.

[0078] In detail, as illustrated in FIG. 13, the quick connector (1700) is composed of a body part (1710), a locking rod (1730), and a locking ball (1750), and may further include a spring (1770).

[0079] First, the body part (1710) has a cavity formed in the center, and the rear end is connected to the coaxial cable sheath (O).

[0080] A locking rod (1730) is inserted and coupled into the cavity of the body part (1710), and its rear end is coupled to the internal wire (W) of the coaxial cable, and preferably, a spring (1770) may be coupled to one side of the outer surface of the locking rod (1730).

[0081] A locking ball (1750) is radially arranged on one side of the front end of the body part (1710) and is configured to be pushed outward as the locking rod (1730) moves backward and forward, thereby engaging with or disengaging from the control rod piston (1400).

[0082] A space (1430) is provided on the upper surface of the control rod piston (1400) so that the quick connector (1700) is inserted therein. More specifically, the space (1430) preferably has an insertion groove (1450) formed therein to accommodate a locking ball (1750) that is pushed outward by the insertion of the locking rod (1730). By having the locking ball (1750) seated in the insertion groove (1450), the quick connector (1700) can be locked inside the control rod piston (1400).

[0084] That is, when assembling the reactor, internal reactor components including a steam generator (200), core shroud (300), core support barrel (400), nuclear fuel assembly (500), control rod cylinder housing (600), control circuit support ring (700), and control rod drive device (1000) are sequentially stacked, and when the reactor cover (800) is covered and the assembly is completed, the control rod cylinder (1200) is combined with the upper part of the control rod guide tube (1100).

[0085] Afterwards, when the control rod drive system (2200) described later is operated, the working fluid flows into the control rod cylinder (1200), and accordingly, the quick connector (1700) moves downward and is inserted and coupled into the space (1430) of the control rod piston (1400).

[0086] At this time, it is preferable that the internal wire (W) of the coaxial cable be kept in a retracted state so that the quick connector (1700) can be inserted into the space (1430).

[0087] Afterwards, the internal wire (W) of the coaxial cable is advanced so that the locking rod (1730) moves along the cavity of the body part (1710) by the force of the spring (1770), causing the locking ball (1750) to be pushed outward and seated in the insertion groove (1450), thereby ensuring that the quick connector (1700) is completely coupled to the control rod piston (1400) so as not to be separated.

[0088] In addition, when the reactor cover (800) is opened to remove nuclear fuel after the reactor is shut down, it is preferable to allow the quick connector (1700) to be separated from the control rod piston (1400) after the coaxial cable internal wire (W) is retracted.

[0089] At this time, the coaxial cable (1600) is automatically rewound by the recovery elastic force of the coil spring (2380) provided in the control rod position measuring system (2300) to be described later, and accordingly, the quick connector (1700) is retracted and positioned at the home position (HP), and the position of the home position (HP) is indicated by FIG. 12.

[0090] Additionally, the control rod (1500) remains in the control rod guide tube (1100), and when the quick connector (1700) is fully retracted, it reaches a state where the reactor cover (800) can be separated.

[0092] FIG. 12 is an enlarged cross-sectional view illustrating the combined structure of the piping and external piping of FIG. 9.

[0093] As shown in FIG. 12, an external pipe (1310) may be connected to the rear end of the pipe (1300), and more specifically, the external pipe (1310) is preferably connected to the rear end of the control circuit ring nozzle (710) with a socket head nut (N) to communicate with the pipe (1300).

[0094] To this end, it is preferable that a thread for fastening a nut is formed on one end of the control circuit ring nozzle (710) and the external pipe (1310).

[0095] That is, by connecting or disconnecting the socket head nut (N) to the control circuit ring nozzle (710), the external piping (1310) can be easily connected or disconnected from the reactor.

[0096] In detail, when separating the external piping (1310) from the reactor, the control rod (1500) is fully inserted into the core while the reactor is stopped, and then the quick connector (1700) is retracted to the groove position (HP) at the end of the external piping (1310), and then the socket head nut (N) is loosened to separate it, thereby separating the reactor control system (2000) described later.

[0097] At the same time, the steam collection unit (2110) of the piping purge system (2100) described later can be separated to complete preparations for disassembling the reactor.

[0099] Unlike conventional technology, the reactor control rod drive device (1000) according to the present invention utilizes a hydraulic cylinder method. In the case of the hydraulic system, it is connected through the reactor side wall (preferably, the control circuit ring nozzle (710)) rather than the reactor cover, thereby separating the reactor control system from the reactor, thus facilitating convenience during nuclear fuel replacement and preventing the weight of the control system for controlling the control rods from being transferred to the reactor.

[0100] However, the installation location of the hydraulic system described above is merely an example and is not limited thereto, as it may be placed in other locations depending on the reactor design.

[0102] Below, we will describe a configuration for measuring the position of a control rod when driving the control rod, referring to FIGS. 9 to 11.

[0103] FIG. 9 is a (A) perspective view and (B) cross-sectional view of a reactor control rod drive device according to the present invention, FIG. 10 is a (A) perspective view and (B) cross-sectional view illustrating an example of installation of a linear potensiometer in a reactor control rod drive device according to the present invention, and FIG. 11 is a (A) perspective view and (B) cross-sectional view illustrating an example of installation of a distance measuring sensor in a reactor control rod drive device according to the present invention.

[0105] As illustrated in FIGS. 10 to 11, the reactor control rod drive device (1000) according to the present invention may further include a method for measuring the position of a control rod (1500) by applying a coil (1810) wound on the outer surface of the control rod cylinder (1200) and a linear potentiometer (1800) coupled along the outer surface of the coil (1810) to measure the position of the control rod (1500), or by applying an ultrasonic sensor or a laser sensor, which is a distance measuring sensor (1900) placed on the upper side of the control rod cylinder (1200), to measure a reflected wave reflected from the top of the control rod (1500) to measure the position of the control rod (1500).

[0106] In the case of the above-mentioned linear potentiometer (1800) or distance measuring sensor (1900) method, the above-mentioned quick connector (1700) and control rod position measuring system (2300) become unnecessary.

[0107] First, FIG. 9 shows a method of measuring the position of a control rod (1500) by directly connecting a coaxial cable (1600) to a control rod (1500) and measuring the length of the coaxial cable (1600). This method is not affected by radiation generated in the reactor, so it can prevent radioactive deterioration of the position measurement system, and has the advantage of being able to withdraw the control rod (1500) using the coaxial cable (1600) in the event that the pump of the control rod drive system (2200) fails.

[0109] Additionally, FIG. 10 describes a method for measuring the position of a control rod (1500) by applying a linear potentiometer (1800). Specifically, a coil (1810) is wound around the outer surface of the control rod cylinder (1200), and the linear potentiometer (1800) measures the position of the control rod (1500) by measuring the change in electromagnetic force generated in the coil (1810) as the position of the control rod (1500) moves.

[0110] Unlike conventional resistance measurement methods, this method can measure the position of the control rods by utilizing changes in inductance.

[0112] Additionally, FIG. 11 is a method for measuring the position of a control rod (1500) by applying a distance measuring sensor (1900) including an ultrasonic sensor or an optical sensor, and the method has the disadvantage that the sensitivity of the sensor must not be degraded by radiation.

[0114] Next, the reactor control system (2000) of the reactor control rod driving device (1000) according to the present invention will be described in detail.

[0115] The reactor control system (2000) is provided outside the reactor and includes a pipe purge system (2100), a control rod drive system (2200), a control rod position measurement system (2300), and a reactor emergency shutdown system (2400), as shown in FIG. 14.

[0116] FIG. 14 is a configuration diagram of a piping purge system, a control rod driving system, a control rod position measurement system, and a reactor emergency shutdown system according to the present invention.

[0117] As illustrated in FIG. 14, the pipe purge system (2100) according to the present invention is intended to remove the working fluid in a steam state formed in the pipe (1300) so that the reactor control system (2000) can operate normally. It is preferably formed on one side of an external pipe (1310) connected to the rear end of the pipe (1300), and more specifically, on one side of a control circuit ring nozzle (710).

[0118] More specifically, the piping purge system (2100) comprises a steam collection unit (2110) having an internal space for collecting the working fluid in a steam state, a purge pipe (2130) connecting the steam collection unit (2110) and a reactor coolant high-pressure storage tank, and a purge valve (2150) formed on one side of the purge pipe (2130).

[0119] More specifically, steam may be generated inside the control rod cylinder (1200) and piping (1300) due to high temperature during reactor operation, and this must be discharged.

[0120] Additionally, during the assembly process of the reactor, it is necessary to discharge air remaining inside the piping (1300). To this end, it is preferable to form a steam collection unit (2110) for steam discharge at the uppermost position of the external piping (1310) connected to the rear end of the piping (1300) or the control circuit support ring (710), and the steam collected in the steam collection unit (2110) is returned to the reactor coolant high-pressure storage tank through the purge piping (2130), as shown in FIG. 17.

[0121] FIG. 17 is a (A) perspective view and (B) cross-sectional view illustrating the combined structure of an external piping and a piping purge system according to the present invention.

[0122] In detail, when the cooling fluid evaporates inside the pipe (1300) and steam is formed, the internal pressure expands as a result, and the pressure is pushed in the insertion direction of the control rod (1500) or detected as a pressure rise signal by a pressure sensor.

[0123] Such abnormal conditions can be detected by the control rod position measurement system (2300) as a change in position, and when such an abnormal signal occurs, the purge valve (2150) must be opened to discharge steam, and during normal operation, the purge valve (2150) remains in a closed state.

[0124] The above purge valve (2150) also performs the function of discharging bubbles formed in the piping (1300) before initial operation after reactor assembly, and the steam and bubbles discharged through the above purge valve (2150) are discharged into a high-pressure storage tank for reactor cooling water to prevent radioactive material from leaking to the outside.

[0125] The above purge valve (2150) is merely an example, and it is preferable to remove the steam formed inside the pipe (1300) by other methods, such as by naturally condensing the steam due to a low temperature outside the reactor or by injecting low-temperature cooling water into the uppermost part of the pipe (1300) to condense the steam, so as not to cause problems in the operation of the reactor control system (2000).

[0127] As illustrated in FIG. 14, the control rod drive system (2200) is for controlling the insertion or withdrawal position of the control rod piston (1400) by supplying working fluid into the control rod cylinder (1200), and includes a first working fluid supply pipe (2210), a drive pump (2220), a first working fluid high-pressure tank (2230), a first injection pump (2240), a first shut-off valve (2250), and a first supply valve (2260), and is driven when adjusting the position of the control rod (1500) in the nuclear fuel assembly (500) during normal operation of the reactor.

[0128] The first working fluid supply pipe (2210) is connected to the rear end of the pipe (1300) to supply working fluid from the reactor coolant high-pressure storage tank to the pipe (1300).

[0129] In detail, it is preferable that the first working fluid supply pipe (2210) is connected to one side of the external pipe (1310) and communicates with the pipe (1300) that guides the flow of working fluid into the reactor.

[0130] The drive pump (2220) is provided on one side of the first working fluid supply pipe (2210), and it is preferable that it be configured to supply or discharge a certain amount of working fluid into or out of the control rod cylinder (1200) by using a metering pump.

[0131] Accordingly, it is possible to indirectly determine the position of the control rod (1500) based on the volume of the working fluid supplied or discharged by the drive pump (2220).

[0132] The first working fluid high-pressure tank (2230) supplies working fluid to the drive pump (2220).

[0133] The first injection pump (2240) is provided between the first working fluid high-pressure tank (2230) and the reactor coolant high-pressure storage tank, and discharges the working fluid supplied from the reactor coolant high-pressure storage tank to the first working fluid high-pressure tank (2230).

[0134] The first shut-off valve (2250) is provided at the rear end of the drive pump (2220), and the first supply valve (2260) is provided at the front end of the first injection pump (2240).

[0135] That is, the first injection pump (2240) operates to receive working fluid from the reactor coolant high-pressure storage tank and maintain a constant level in the first working fluid high-pressure tank (2230).

[0136] The drive pump (2220) is a metering pump configured to discharge a certain amount of working fluid into the control rod cylinder (1200) or to discharge a certain amount of working fluid from the control rod cylinder (1200).

[0137] In addition, the control rod drive system (2200) is equipped with a first shut-off valve (2250) and a first supply valve (2260) so that the pressure within the system is stably maintained.

[0138] That is, when a certain amount of working fluid is supplied into the control rod cylinder (1200) by the control rod driving system (2200) of the configuration described above, the control rod (1500) reaches a target position within the core.

[0139] Afterwards, by stopping the operation of the drive pump (2220) and closing the first shut-off valve (2250), the position of the control rod (1500) is fixed, and the internal and external pressures of the control rod cylinder (1200) are maintained equally.

[0141] Next, the control rod position measuring system (2300) is configured to control the forward and backward movement of the coaxial cable (1600) and consists of a housing (2310), a pulley (2320), a magnet receiving groove (2330), a pulley shaft (2340), a permanent magnet (2350), and a solenoid electromagnet (2360).

[0142] Additionally, the control rod position measuring system (2300) may further include an encoder magnet (2370), a clock spring (2380), and an encoder (2390) to measure the position of the control rod (1500) according to the forward and backward movement of the coaxial cable (1600), as shown in FIG. 15 and FIG. 16.

[0143] FIG. 15 is a cross-sectional view of a control rod position measuring system according to the present invention, and FIG. 16 is a cross-sectional perspective view of a control rod position measuring system according to the present invention.

[0145] As shown in FIG. 15, it is preferable that the housing (2310) be connected to the end of the external pipe (1310) so that a coaxial cable (1600) can be inserted on one side.

[0146] In addition, the housing (2310) is connected to the reactor through the external pipe (1310), so it forms a reactor pressure boundary and must be completely sealed to prevent leakage of the radioactive working fluid (reactor coolant) flowing inside.

[0147] The pulley (2320) is located inside the housing (2310), where the coaxial cable (1600) is wound, and magnet receiving grooves (2330) are provided at the top and bottom respectively.

[0148] The pulley shaft (2340) is formed with a guide tube (2341) that guides the end of the coaxial cable (1600) wound on the pulley (2320) toward the upper magnet receiving groove (2330).

[0149] Preferably, the guide tube (2341) is formed with a coaxial cable fixing part (2343) that protrudes inwardly from the inner circumference of the end adjacent to the upper magnet receiving groove (2330) and is formed so that the inner diameter narrows.

[0150] The inner circumferential diameter of the above-mentioned coaxial cable fixing part (2343) is formed to be the same or similar diameter as the coaxial cable outer sheath (O), so that the coaxial cable outer sheath (O) is caught on the coaxial cable fixing part (2343) and cannot pass through, thus being fixed to the coaxial cable fixing part (2343), and the coaxial cable inner wire (W) passes through the coaxial cable fixing part (2343) and is coupled to one end of the permanent magnet (2350) to be described later (specifically, the coaxial cable wire fixing part (2351)).

[0151] The permanent magnet (2350) is inserted into the upper magnet receiving groove (2330), and the end of the coaxial cable internal wire (W) is connected and fixed to the coaxial cable wire fixing part (2351) to be described later.

[0152] That is, as shown in (B) of FIG. 15, it is preferable that a coaxial cable wire fixing part (2351) be formed in the central part of the permanent magnet (2350) so that the end of the coaxial cable internal wire (W) can be inserted and coupled.

[0153] The solenoid electromagnet (2360) is coupled to the upper outer side of the housing (2310), and an attractive or repulsive force is generated on the permanent magnet (2350) by the magnetic field applied to the solenoid electromagnet (2360), causing the internal wire (W) of the coaxial cable to move forward or backward. That is, the permanent magnet (2350) is located inside the reactor pressure boundary, and the solenoid electromagnet (2360) is located outside the reactor pressure boundary to prevent leakage of radioactive reactor coolant.

[0154] This advances or retracts the locking rod (1730) of the quick connector (1700) connected to the opposite end of the coaxial cable (1600), and as a result, the quick connector (1700) and the control rod piston (1400) are connected or separated.

[0156] Below, the configuration of the encoder magnet (2370), the mainspring (2380), and the encoder (2390) will be described in detail.

[0157] First, the encoder magnet (2370) is inserted into the lower magnet receiving groove (2330) and is preferably coupled to rotate integrally with the pulley (2320).

[0158] The encoder (2390) is coupled to the lower outer side of the housing (2310) to measure the rotation (i.e., number of rotations and angle of rotation) of the encoder magnet (2370) and calculate the position of the control rod (1500). Similar to the solenoid electromagnet (2360), the encoder (2390) is installed outside the reactor pressure boundary.

[0159] In detail, the encoder magnet (2370) is in the form of a plurality of small magnets arranged along the circumferential direction and is positioned to face each other with the encoder (2390).

[0160] That is, when the pulley (2320) rotates, the amount of rotation of the pulley (2320) can be measured through the encoder (2390), and based on the amount of rotation of the pulley (2320), the amount of winding or unfolding of the coaxial cable (1600) can be calculated, respectively, and through this, it is possible to calculate the insertion or withdrawal distance of the control rod (1500).

[0161] In detail, the present invention calculates the rotational speed of the drive pump (2220) of the control rod drive system (2200) to estimate the insertion and withdrawal positions of the control rod (1500) according to the flow rate, but since this may result in errors due to leakage of the working fluid, the invention intends to measure the accurate position of the control rod (1500) by a direct method by installing an encoder magnet (2370) and an encoder (2390).

[0162] Next, a mainspring (2380) is provided along the lower outer surface of the pulley (2320), with both ends connected to the pulley (2320) and the housing (2310), respectively, to provide a rewinding rotational force to the pulley (2320).

[0163] More specifically, the mainspring is a type of spring having a spirally wound structure, one end of which is fixed to a pulley (2320) and the other end is connected to a housing (2310).

[0164] The coaxial cable (1600) is maintained wound on the pulley (2320) by the initial tension of the mainspring (2380).

[0165] At this time, when pressure is applied to the quick connector (1700) and it moves forward according to the operation of the drive pump (2220), the coaxial cable (1600) wound on the pulley (2320) is unwound, and the quick connector (1700) is connected to the control rod piston (1400).

[0166] Afterwards, when the solenoid electromagnet (2360) is energized, it pushes out the permanent magnet (2350), and accordingly, the locking rod (1730) of the quick connector (1700) at the opposite end connected to the coaxial cable internal wire (W) advances, and the quick connector (1700) is coupled to the space (1430) of the control rod piston (1400).

[0167] Additionally, when the magnetic force of the solenoid electromagnet (2360) is removed, the locking rod (1730) of the quick connector (1700) is retracted by the elastic force of the spring (1770) of the quick connector (1700), and as a result, the quick connector (1700) is separated from the control rod piston (1400).

[0168] At this time, the quick connector (1700) is retracted by the drive pump (2220) while separated from the control rod piston (1400), and the coaxial cable (1600) connected to the quick connector (1700) must also be retracted.

[0169] That is, the pulley (2320) rotates in the opposite direction due to the restoring force of the mainspring (2380), and accordingly, the coaxial cable (1600) is rewound on the pulley (2320). As a result, the quick connector (1700) located at the end of the coaxial cable (1600) retracts and moves to the home position (HP).

[0171] Meanwhile, the control rod position measurement system (2300) may further include a power supply unit (not shown) and a position analysis unit (not shown), and the power supply unit may be configured to supply power to the solenoid electromagnet (2360) to form a magnetic field, and may further include a measurement control circuit that transmits a measurement signal.

[0172] Additionally, the position analysis unit receives position information of the control rod (1500) measured from the encoder (2390), and if the position of the control rod (1500) deviates from a preset range, it can operate the drive pump (2220) of the control rod drive system (2200) to adjust the position of the control rod (1500) to within the preset range and maintain it.

[0173] This concludes the description of the configuration of the control rod position measurement system (2300).

[0175] Next, as illustrated in FIG. 14, the reactor emergency shutdown system (2400) is operated to shut down the reactor by supplying a working fluid at high pressure into the control rod cylinder (1200) during abnormal operation of the reactor and rapidly inserting the control rod (1500) into the reactor core, and includes a second working fluid supply pipe (2410), a second working fluid high-pressure tank (2420), a second injection pump (2430), a second shut-off valve (2440), and a second supply valve (2450).

[0176] The second working fluid supply pipe (2410) is connected to the downstream end of the pipe (1300) and supplies the working fluid in the reactor coolant high-pressure storage tank to the pipe (1300) during abnormal operation of the reactor.

[0177] In detail, it is preferable that the second working fluid supply pipe (2410) be connected to one side of the external pipe (1310) and communicate with the pipe (1300) inside the reactor.

[0178] The second working fluid high-pressure tank (2420) is provided on one side of the second working fluid supply pipe (2410).

[0179] The second injection pump (2430) is provided between the second working fluid high-pressure tank (2420) and the reactor coolant high-pressure storage tank, and discharges the working fluid supplied from the reactor coolant high-pressure storage tank to the second working fluid high-pressure tank (2420).

[0180] The second shut-off valve (2440) is provided at the rear end of the second working fluid high-pressure tank (2420), and the second supply valve (2450) is provided at the front end of the second injection pump (2430).

[0181] Preferably, the second shut-off valve (2440) is installed in a second working fluid supply pipe (2410) coupled to each control rod drive system (2200), and the opening of the second shut-off valve (2440) is characterized by inserting the entire control rod (1500) into the core.

[0182] That is, a second supply valve (2450) is installed at the front end of the second working fluid supply pipe (2410), and a second shut-off valve (2440) is installed at the rear end to prevent pressure leakage of the second working fluid high-pressure tank (2420).

[0183] That is, the reactor emergency shutdown system (2400) of the above-described structure receives working fluid from a reactor coolant high-pressure storage tank formed outside the reactor, and the supplied working fluid is pressurized to a higher pressure through a second injection pump (2430) and stored in a second working fluid high-pressure tank (2420).

[0184] Since the second working fluid high-pressure tank (2420) must be able to insert all control rods (1500) into the core at the same time, it is desirable that it be designed to maintain a higher pressure than the first working fluid high-pressure tank (2230) and have a larger capacity.

[0185] Meanwhile, the second working fluid supply pipe (2410) is connected to a pipe (1300) or an external pipe (1310) that is connected to each control rod (1500), and it is preferable that a second shut-off valve (2440) be installed at the front end of each second working fluid supply pipe (2410).

[0186] That is, during normal operation of the reactor, the locked state is maintained to block the high pressure inside the second working fluid supply pipe (2410) from being transmitted to the first working fluid supply pipe (2210).

[0187] In the event of abnormal operation of the reactor (i.e., an emergency), the second shut-off valve (2440) is opened, and the reactor is shut down by rapidly inserting a plurality of control rods (1500) into the reactor core simultaneously.

[0188] At this time, after the control rod (1500) is fully inserted into the core, the control rod driving system (2200) operates to stably maintain the state in which the control rod is inserted.

[0189] Meanwhile, the control rod drive system (2200), control rod position measurement system (2300), and pipe purge system (2100) must be designed and manufactured to withstand the high pressure of the reactor emergency shutdown system (2400).

[0190] As described above, the reactor control system (2000) is composed of a piping purge system (2100), a control rod drive system (2200), a control rod position measurement system (2300), and a reactor emergency shutdown system (2400), and the piping connected to each system must be assembled so as not to leak reactor coolant. Accordingly, the reactor pressure boundary is formed by connecting by welding or other methods, and leakage must not occur under any operating conditions or failure conditions.

[0191] This concludes the description of the reactor control system (2000).

[0193] Next, the reactor control rod drive device (1000) according to the present invention may further include a multi-connector (3000) provided between the pipe (1300) and the external pipe (1310) for simultaneously connecting a plurality of pipes (1300) and the external pipe (1310), as shown in FIG. 18.

[0194] FIG. 18 is a (A) perspective view and (B) exploded view illustrating the combination of a pipe, an external pipe, and a multi-connector according to the present invention.

[0195] As illustrated in FIG. 18, the multi-connector (3000) is composed of a multi-connector nozzle (3100) provided at the end of a plurality of pipes (1300), a multi-connector adapter (3300) provided at the end of a plurality of external pipes (1310) and coupled to one side of the multi-connector nozzle (3100), and a socket (3500) provided at the coupling portion of the multi-connector nozzle (3100) and the multi-connector adapter (3300).

[0197] When connecting multiple pipes (1300) to the reactor side wall or the control circuit support ring (700), the multi-connector (3000) can be applied to connect multiple pipes (1300) to the external pipe (1310) all at once.

[0198] At this time, the multi-connector nozzle (3100) is connected through the reactor sidewall or the control circuit support ring (700) to become a pressure boundary connecting the pipe (1300) and the external pipe (1310).

[0199] In particular, it is desirable that the joint portion of the multi-connector nozzle (3100) and the multi-connector adapter (3300) be sealed with a face seal (S) or the like to prevent leakage of the working fluid.

[0201] That is, the present invention can provide the effect of reducing the time required for connecting and disassembling the reactor driving device and the reactor control system by introducing a multi-connector (3000), and since the above-described multi-connector configuration operates identically or similarly to the prior art, a detailed description is omitted.

[0203] Although the present invention has been described above with reference to the embodiments illustrated in the drawings, this is merely for the purpose of explaining the invention, and those skilled in the art will understand that various modifications or equivalent embodiments are possible from the detailed description of the invention.

[0204] Therefore, the true scope of rights of the present invention must be determined by the technical concept of the patent claims. Explanation of the symbols

[0206] 10: Reactor 20: Reactor cover 30 : Core 40: Control rod protection tube 50: Control rod drive unit 60: Nuclear fuel assembly 70: Control rod guide tube 80:4-element control rod assembly 90:12-element control rod assembly 100: Reactor vessel 200 : Steam generator 210: Steam exhaust section 300: Core Shroud 310: Neutron reflector 400 : Core support barrel 500: Nuclear fuel assembly 510: Nuclear fuel rod 600 : Control rod cylinder housing 610: Cylinder housing top plate 620 : Cylinder housing bottom plate 630 : Cylinder housing side plate 700: Control circuit support ring 710: Control circuit ring nozzle 800: Reactor cover 900: Coolant pump 1000 : Control rod drive unit 1100: Control rod guide tube 1200: Control rod cylinder 1300 : Piping 1310 : External piping N : Socket head nut 1400 : Control rod piston 1410 : Sealing 1430 : Space part 1450 : Insertion slot 1500 : Control rods 1600 : Coaxial cable O : Coaxial cable sheath W : Internal wire of coaxial cable 1700 : Quick Connector 1710 : Body 1730 : Locking rod 1750 : Locking ball 1770 : Spring 1800 : Linear potentiometer 1810 : Coil 1900: Distance measuring sensor 2000: Reactor Control System 2100 : Piping Purge System 2110: Steam collector 2130 : Purge piping 2150 : Purge valve 2200: Control Rod Drive System 2210 : 1st working fluid supply pipe 2220 : Drive pump 2230 : 1st Working Fluid High-Pressure Tank 2240 : 1st injection pump 2250 : First shut-off valve 2260 : First supply valve 2300: Control Rod Position Measurement System 2310 : Housing 2320 : Pulley 2330 : Magnet receiving groove 2340 : Pulley shaft 2341 : Guide Hall 2343 : Coaxial cable fixing part 2350: Permanent magnet 2351 : Coaxial cable wire fixing part 2360 : Solenoid electromagnet 2370 : Encoder magnet 2380 : Clockwork spring 2390 : Encoder 2400: Reactor Emergency Shutdown System 2410 : Second working fluid supply pipe 2420 : Second working fluid high-pressure tank 2430 : Second injection pump 2440 : Second shut-off valve 2450 : Second supply valve 3000 : Multi-connector 3100 : Multi-connector nozzle 3300 : Multi-connector adapter 3500 : Socket

Claims

Claim 1 A reactor control rod drive device characterized by comprising: a plurality of control rod guide tubes installed between a plurality of nuclear fuel rods, into which a control rod is inserted; a control rod cylinder coupled to the upper part of the control rod guide tubes; a pipe connecting the control rod cylinder to the reactor side wall to guide a working fluid flowing in from outside the reactor into the control rod cylinder; and a control rod piston coupled to the upper part of the control rod and configured to move in an up-and-down direction by the pressure of the working fluid. Claim 2 A reactor control rod drive device according to claim 1, further comprising: a coaxial cable installed along the inside of the pipe; and a quick connector coupled to the end of the coaxial cable and provided inside the control rod cylinder, wherein a space is formed on the upper surface of the control rod piston to allow the quick connector to be inserted and coupled. Claim 3 A reactor control rod driving device according to claim 2, further comprising a control rod position measuring system located outside the reactor and controlling the forward and backward movement of the coaxial cable, wherein the control rod position measuring system comprises a housing, a pulley located inside the housing on which the coaxial cable is wound, a magnet receiving groove provided on the upper part of the pulley, a pulley shaft having a guide tube formed therein to guide the end of the coaxial cable wound on the pulley toward the magnet receiving groove, a permanent magnet inserted into the magnet receiving groove and to which the end of the coaxial cable is connected and fixed, and a solenoid electromagnet coupled to the upper side of the housing. Claim 4 In paragraph 3, the control rod position measuring system further comprises a magnet receiving groove provided at the lower part of the pulley, an encoder magnet inserted into the magnet receiving groove at the lower part, a spring provided along the lower outer surface of the pulley with both ends connected to the pulley and the housing respectively, and an encoder connected to the lower part of the housing to measure the rotation of the encoder magnet, thereby measuring the position of the control rod according to the forward and backward movement of the coaxial cable. Claim 5 A reactor control rod drive device according to claim 1, further comprising an external pipe connected to the rear end of the pipe; wherein a pipe purging system is provided on one side of the external pipe, the external pipe comprising a steam collection unit having an internal space for collecting the steam-state working fluid formed in the pipe for removing the steam-state working fluid formed in the pipe, a purging pipe connecting the steam collection unit to a reactor coolant high-pressure storage tank, and a purging valve formed on one side of the purging pipe. Claim 6 A reactor control rod drive device according to claim 1, further comprising: a control rod drive system located outside the reactor and controlling the insertion or withdrawal position of a control rod piston by supplying a working fluid; wherein the control rod drive system comprises: a first working fluid supply pipe formed at the rear end of the pipe and supplying a working fluid within a reactor coolant high-pressure storage tank to the pipe; a drive pump provided on one side of the first working fluid supply pipe; a first working fluid high-pressure tank that supplies a working fluid to the drive pump; a first injection pump provided between the first working fluid high-pressure tank and the reactor coolant high-pressure storage tank and discharges a working fluid supplied from the reactor coolant high-pressure storage tank toward the first working fluid high-pressure tank; a first shut-off valve provided at the rear end of the first metering pump; and a first supply valve provided at the front end of the first injection pump. Claim 7 A reactor control rod driving device according to claim 6, further comprising a reactor emergency shutdown system that stops the reactor by supplying a working fluid at high pressure and inserting a control rod into the core during abnormal operation of the reactor, wherein the reactor emergency shutdown system comprises: a second working fluid supply pipe formed at the downstream end of the pipe and supplying a working fluid in a reactor coolant high-pressure storage tank to the pipe during abnormal operation of the reactor; a second working fluid high-pressure tank provided on one side of the second working fluid supply pipe; a second injection pump provided between the second working fluid high-pressure tank and the reactor coolant high-pressure storage tank and discharges a working fluid supplied from the reactor coolant high-pressure storage tank to the second working fluid high-pressure tank; a second shut-off valve provided at the downstream end of the second working fluid high-pressure tank; and a second supply valve provided at the upstream end of the second injection pump. Claim 8 A reactor control rod driving device according to claim 5, further comprising a multi-connector provided between a pipe and an external pipe for simultaneously connecting the plurality of pipes with an external pipe; wherein the multi-connector comprises a multi-connector nozzle provided at the end of a plurality of pipes, a multi-connector adapter provided at the end of a plurality of external pipes and coupled to one side of the multi-connector nozzle, and a socket provided at the coupling portion of the multi-connector nozzle and the multi-connector adapter. Claim 9 A reactor control rod driving device according to claim 1 or 2, further comprising a coil wound on the outer surface of the control rod cylinder and a linear potentiometer coupled along the outer surface of the coil, or a distance measuring sensor disposed on the upper side of the control rod cylinder, for measuring the position of the control rod.

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