KR101802840B1 - Reactor coolant pump and integral reactor having the same - Google Patents

Abstract

The present invention relates to a reactor coolant pump and an integrated reactor having the same, comprising: a motor mounted on an external wall side surface of a reactor container; an impeller accommodated in the reactor container, connected to the motor, receiving power from the motor, and circulating a reactor coolant of an internal structure of the reactor container; and a bypass flow reduction portion provided in a gap between an internal structure of the reactor container guiding the reactor coolant to the impeller and a pump channel structure for guiding the reactor coolant sent by the impeller to a steam generator, sealing the gap between the internal structure of the reactor container and the pump channel structure by using at least one of elasticity and length expansion caused by temperature increase of the reactor coolant, and reducing the bypass flow of the reactor coolant that is to be bypassed through the gap, thereby capable of minimizing the bypass flow that can be occurred due to the gap between the internal structure of the reactor vessel and the pump channel structure.

Description

REACTOR COOLANT PUMP AND INTEGRAL REACTOR HAVING THE SAME BACKGROUND OF THE INVENTION 1. Field of the Invention [0001]

The present invention relates to a reactor coolant pump capable of more efficiently utilizing a circulating flow rate of a reactor coolant and an integrated reactor having the same.

Nuclear reactors consist of a separate reactor (eg commercial reactor: Korea) in which the main equipment (steam generator, pressurizer, impeller of the reactor coolant pump, etc.) is installed outside the reactor vessel depending on the installation position of the main equipment (For example, SMART reactor: Korea).

In addition, the water-tight reactor can be classified into a boiling light-water reactor that allows the boil-off of the reactor coolant and a pressurized light-water reactor that does not allow boiling and maintains a supercooled state by the pressurizer.

In the pressurized light water reactor, the reactor coolant pump circulates the reactor coolant to transfer heat generated from the core to the steam generator.

The reactor coolant pump includes an electric motor that generates rotational power and an impeller that converts rotational power into fluid power.

The reactor coolant pump is divided into a horizontal type and a vertical type according to the installation direction of the pump, and is classified into a centrifugal type, a quadrature type, and an axial type depending on the type of the impeller.

In a separate reactor, the reactor coolant pump is installed in the main pipe connecting the steam generator and the reactor.

In the integrated reactor, the reactor coolant pump is a type in which the motor is mounted on the reactor vessel in such a manner that the motor protrudes outwardly from the outer wall of the reactor vessel and the impeller is accommodated in the reactor vessel or the entire pump including the impeller and the motor is accommodated in the reactor vessel As shown in FIG.

On the other hand, a non-leakage magnetic pump of a type in which two permanent magnets are installed between plates separated from each other to drive the pump while one (main) magnet is rotated (driven) (Refer to the following patent document 1). In addition, a system in which a reactor coolant pump is configured to drive a turbine is proposed (refer to the prior patent document 2 below).

Fig. 1 is a conceptual view showing an integral nuclear reactor 10 and Fig. 2 is a schematic view showing the gap 6 between the pump channel structure 3 of the reactor coolant pump 1 and the internal structure 18 of the reactor vessel 11 in Fig. (7) is generated by the circulation flow.

The integrated reactor 10 is provided with a core 12, a steam generator 13, an impeller 2 of a reactor coolant pump 1, a pressurizer 16 and the like, which are main components of the reactor coolant system, Lt; / RTI >

The reactor coolant pump 1 is mounted on the side surface of the reactor vessel 11 and the impeller 2 and the pump flow path structure 3 are mounted on the flow path of the reactor coolant system inside the reactor vessel 11 And the electric motor is connected to the outer wall connection nozzle 17 of the reactor vessel 11.

Inside the reactor vessel 11 is provided an internal structure 18 for guiding the reactor coolant to the impeller 2 of the reactor coolant pump 1.

The pump channel structure 3 is configured to discharge the reactor coolant that has passed through the impeller 2 from the internal structure 18 to the outside of the heat transfer tube of the steam generator 13. [

The reactor coolant is circulated in the order of the core 12, the reactor coolant pump 1, the steam generator 13, and the core 12 in the reactor coolant system.

The reactor coolant is circulated by a reactor coolant pump 1 mounted on the side of the reactor vessel 11 and is circulated by a core 12 located at the lower center of the reactor vessel 11, A forced circulation flow of the reactor coolant is formed between the steam generators 13 positioned in the annular space between the inner walls of the steam generators 13 and 11 so that the heat generated in the core 12 can be transferred to the secondary side of the steam generator 13 .

The heat transfer in the reactor coolant system is made between the reactor coolant passing through the heat transfer tube outside of the steam generator 13 and the secondary water supply passing through the inside of the heat transfer tube of the steam generator 13. [ The water in the inner side of the heat transfer tube is heated through heat exchange with the reactor coolant and is phase-transformed from abnormal flow to superheated steam flow in a supercooled flow (mixed fluid of liquid and gas) through the header of the steam generator 13 .

The conventional reactor coolant pump 1 receives power from the motor 4 and rotates the impeller 2 to cool the reactor coolant from the internal structure 18 of the reactor vessel 11 to the inside of the pump flow path structure 3 And is discharged into the steam generator 13 through the discharge part 5 at the rear end of the pump flow path structure 3. [

However, in such a structure, it is difficult to form the sealing structure through welding or the like between the inner structure 18 of the reactor vessel 11 and the pump flow path structure 3, The discharged reactor coolant flows into the gap 6 between the internal structure 18 and the pump flow path structure 3 without circulating through the flow path of the reactor coolant system and flows through the gap 6, (7) is generated. The generation of the bypass flow 7 leads to a power loss of the reactor coolant pump 1, which increases the required capacity of the pump.

D1: Patent No. 10-0482982 (Apr. 04, 2005) D2: Patent No. 10-1513139 (Apr. 13, 2015)

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a reactor coolant pump capable of minimizing a bypass flow that can be generated due to a clearance between an internal structure of a reactor vessel and a pump flow path structure in a mounting structure of a reactor coolant pump mounted on a side surface of an integral reactor And to provide an integrated reactor having the same.

To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described herein, there is provided a reactor coolant pump comprising: an electric motor mounted on an outer wall of a reactor vessel; An impeller which is accommodated in the reactor vessel and receives power from the motor to circulate the reactor coolant inside the reactor vessel; Wherein the inner structure of the reactor vessel and the pump flow path structure surrounding the impeller are formed by using at least one of elasticity and expansion due to temperature rise of the reactor coolant, And a bypass flow rate reducing section for reducing the bypass flow rate of the reactor coolant to bypass through the gap.

According to one embodiment of the present invention, the bypass flow reducing portion may include a bellows or a spring.

According to an embodiment of the present invention, the bypass flow reducing section may have one side fixed to the pump flow path structure and the other side expanding to an internal structure of the reactor vessel.

According to another embodiment of the present invention, the bypass flow reducing portion may have one side fixed to the internal structure of the reactor vessel and the other side expanding to the pump flow path structure.

According to an embodiment of the present invention, the bypass flow reducing unit further includes a sealing member formed integrally with the bellows and moved by the expansion of the bellows to closely contact the internal structure of the reactor vessel or the pump flow path structure can do.

According to another embodiment of the present invention, the bypass flow reducing portion is formed integrally with the spring, and the sealing member is moved by the expansion of the spring to closely contact the inner structure of the reactor vessel or the pump flow path structure .

According to another aspect of the present invention, the bypass flow reduction unit may include a portion of the spring to enclose the outer side and the inner side of the spring, And a sealing member which is in close contact with the pump flow path structure.

According to an embodiment of the present invention, the bypass flow reducing portion includes a guide portion provided in the pump channel structure to guide the expansion of the spring, wherein the guide portion includes: an inner guide portion surrounding the inside of the spring; And an outer guiding portion surrounding the outer side of the spring.

According to another embodiment of the present invention, the bypass flow reducing section includes a guide portion provided in the pump channel structure to guide the expansion of the bellows, wherein the guide portion includes: an inner guide portion surrounding the inside of the bellows; And an outer guiding portion surrounding the outer side of the bellows.

According to one embodiment of the present invention, the bypass flow reducing portion may be fastened by a screw or welding.

According to an embodiment of the present invention, the spring may be any one of a coil spring, a disk spring, and a volute spring.

According to an embodiment related to the present invention, the sealing member is integrally formed on the front end of the bellows, and an incision part in which the end of the sealing member is partially cut is disposed so as to be spaced apart in the circumferential direction, It can be pushed radially inward of the sealing member or can be spread outward.

According to an embodiment related to the present invention, the sealing member is integrally formed at the front end of the spring, and a cutout portion in which the end of the sealing member is partially cut is disposed so as to be spaced apart in the circumferential direction, It can be pushed radially inward of the sealing member or can be spread outward.

According to one example related to the present invention, the end portions of the sealing member may be alternately arranged in the circumferential direction and alternately arranged in the circumferential direction by the cut-out portion, and may be alternately pinched or widened radially inwardly and outwardly of the sealing member.

According to an embodiment of the present invention, the electric motor includes: a stator and a rotor that generate a rotational force by an electromagnetic interaction; A rotary shaft having one side connected to the rotor and the other side projecting to the inside of the reactor vessel and connected to the impeller; And a casing that protrudes outward from an outer wall side of the reactor vessel and surrounds the stator and the rotor and a part of the rotation shaft.

According to an embodiment of the present invention, the rotary shaft may be disposed to extend in the radial direction of the reactor vessel.

According to another aspect of the present invention, there is provided an integrated nuclear reactor comprising: a reactor vessel for receiving therein a core, a steam generator, and a pressurizer; A reactor coolant pump for circulating the reactor coolant stored in the reactor vessel, the reactor coolant pump including an impeller rotatably received in the reactor vessel and an electric motor rotating the impeller; A pump channel structure accommodated in the reactor vessel and surrounding a periphery of the impeller and discharging the reactor coolant discharged by the impeller to the steam generator; An internal structure provided inside the reactor vessel for guiding the reactor coolant from the core to a front end of the impeller; And a spring or a bellows between the pump channel structure and the internal structure, wherein a gap between the pump channel structure and the internal structure is formed by elasticity of the spring or the bellows or by expansion of the spring or bellows due to heat of the reactor coolant, And a bypass flow rate reducing section for sealing the bypass flow rate.

According to the present invention configured as described above, the following effects can be obtained.

First, the circulation flow rate of the reactor coolant circulated by the reactor coolant pump can be efficiently utilized by reducing the bypass flow rate by minimizing the gap formed between the reactor coolant pump and the reactor internal structure in the integral reactor.

Second, as the circulation flow rate of the reactor coolant increases, the thermal margin of the core can be increased to enhance the safety of the nuclear reactor.

Third, as the bypass flow rate of the reactor coolant not participating in the cooling of the reactor is reduced, the capacity of the reactor coolant pump can be efficiently reduced while maintaining the cooling performance of the reactor coolant system, and the reactor coolant pump can be downsized. The economic efficiency can be improved.

1 is a conceptual diagram showing an integral nuclear reactor.
FIG. 2 is a conceptual diagram showing a bypass flow rate generated by a gap between a pump flow path structure of a reactor coolant pump and an internal structure of a reactor vessel in FIG.
3 is a conceptual diagram showing a state in which a reactor coolant pump to which a bypass flow reduction apparatus according to the first embodiment of the present invention is applied is installed in an integrated reactor.
FIG. 4 is a conceptual view showing a state in which a spring is accommodated in the interior of the sealing member in FIG. 3 in a stereoscopic manner.
FIG. 5 is a conceptual view showing the operation of the reactor coolant pump in FIG. 3.
6 is a conceptual diagram showing a state in which a reactor coolant pump to which a bypass flow reduction apparatus according to a second embodiment of the present invention is applied is installed in an integrated reactor.
FIG. 7 is a conceptual view showing the operation of the reactor coolant pump in FIG.
8 is a conceptual diagram showing a state where a reactor coolant pump to which a bypass flow reduction apparatus according to a third embodiment of the present invention is applied is installed in an integrated reactor.
9 is a conceptual diagram showing a state in which a reactor coolant pump to which a bypass flow reduction apparatus according to a fourth embodiment of the present invention is applied is installed in an integrated reactor.
10 is a conceptual diagram showing a state where a reactor coolant pump to which a bypass flow reducing apparatus according to a fifth embodiment of the present invention is applied is installed in an integrated reactor.
11 is a conceptual diagram showing a state in which a reactor coolant pump to which a bypass flow reducing apparatus according to a sixth embodiment of the present invention is applied is installed in an integrated reactor.
12 is a conceptual diagram showing a state in which a reactor coolant pump to which a bypass flow reduction apparatus according to a seventh embodiment of the present invention is applied is installed in an integrated reactor.
13 is a conceptual diagram showing a state where a reactor coolant pump to which a bypass flow reduction apparatus according to an eighth embodiment of the present invention is applied is installed in an integrated reactor.
FIG. 14 is a conceptual diagram showing a state in which a reactor coolant pump to which a bypass flow reduction apparatus according to a ninth embodiment of the present invention is applied is installed in an integrated reactor.
15 is a conceptual diagram showing a bypass flow reducing apparatus according to a tenth embodiment of the present invention.
16 is a conceptual diagram showing a bypass flow reducing apparatus according to an eleventh embodiment of the present invention.
17 is a conceptual diagram showing a bypass flow reducing apparatus according to a twelfth embodiment of the present invention.
18 is a conceptual diagram showing a bypass flow reducing apparatus according to a thirteenth embodiment of the present invention.
19 to 24 are conceptual diagrams showing various spring and bellows shapes according to an embodiment of the present invention.

Hereinafter, a reactor coolant pump according to the present invention and an integral nuclear reactor having the same will be described in detail with reference to the drawings. The singular expressions include plural expressions unless the context clearly dictates otherwise.

In the following description of the embodiments of the present invention, a detailed description of related arts will be omitted when it is determined that the gist of the embodiments disclosed herein may be obscured.

3 is a conceptual view showing a state where a reactor coolant pump to which a bypass flow reduction apparatus according to the first embodiment of the present invention is applied is installed in an integrated reactor, FIG. 4 is a cross- FIG. 5 is a conceptual view showing the operation of the reactor coolant pump in FIG. 3. FIG.

Referring to FIG. 1, the reactor coolant system is a system for transferring thermal energy generated by nuclear fission in a core 12 to a secondary system through a steam generator 13. The reactor coolant system in the integrated reactor (10) includes facilities installed inside the reactor vessel (11) and the reactor vessel (11).

The reactor vessel 11 is filled with a primary fluid (also referred to as a 'reactor coolant') that cools the nuclear fuel. The steam generator 12 receives heat energy from the core 12 and converts the water in the secondary system into steam. (13).

The steam generator 13 receives heat from the core 12 and receives steam (secondary fluid) from the secondary water supply (secondary fluid) supplied through the main water supply pipe 14 connected to the lower inlet header, . The feed water is converted into steam in the steam generator 13 and is transferred to the turbine system (not shown) through the main engine 15.

The reactor coolant system forms a pressure boundary between the primary fluid accommodated in the reactor vessel 11 and the secondary fluid passing through the steam generator 13 to isolate the primary fluid and the secondary fluid from each other, .

The reactor coolant pump 20 circulates the primary fluid filled in the reactor coolant system to cool the fuel. The high temperature primary fluid that has received heat from the core 12 while cooling the core 12 rises and the reactor coolant pump 20 circulates the primary fluid (hereinafter referred to as reactor coolant) back down.

An internal structure 18 is provided inside the reactor vessel 11 and an internal structure 18 between the core 12 and the reactor coolant pump 20 is provided for circulating the reactor coolant by the reactor coolant pump 20. [ It is possible to provide a flow path for circulating the reactor coolant.

Referring to FIGS. 1 and 3, a core 12 is disposed at the inner lower center of the reactor vessel 11. The reactor coolant pump 20 is mounted on the upper side of the outer wall of the reactor vessel 11 through a connecting nozzle 17. However, since the installation position of the reactor coolant pump 20 may differ depending on the characteristics of the nuclear power plant, the installation position is not limited to the upper side of the outer wall side of the reactor vessel 11.

The reactor coolant pump 20 may include an impeller 21, a rotary shaft 23, an electric motor 25, a diffuser 22, and a pump flow path structure 24. The impeller 21 of the reactor coolant pump 20, the rotary shaft 23, the diffuser 22 and the pump flow path structure 24 are connected to the reactor vessel 11 through the connection nozzle 17 on the side of the reactor vessel 11, The reactor coolant pump 20 can be mounted on the side of the reactor vessel 11 such that the motor 25 of the reactor coolant pump 20 protrudes from the outer wall of the reactor vessel 11 .

The reactor coolant pump 20 may be a canned motor pump that does not use a pump shaft sealing device.

The impeller 21 converts circulating power into fluid power, thereby providing circulating power to the reactor coolant. The impeller 21 is coupled to the front end of the rotary shaft 23 and can be rotated together with the rotary shaft 23.

The diffuser 22 is disposed inside the reactor vessel 11 and is used for a process of changing the dynamic energy (flow rate) of the reactor coolant (fluid) discharged from the impeller 21 to the static energy (static pressure) It is installed to reduce the pressure loss.

The pump flow path structure 24 may be formed in a cylindrical shape to enclose the impeller 21 and the diffuser 22. An inlet 24a is formed on the front surface of the pump channel structure 24 on the basis of the direction in which the reactor coolant flows and a discharge portion 24b is formed radially in the rear end portion of the pump channel structure 24 .

An internal structure (18) is provided inside the reactor vessel (11) to provide a flow path for the circulation of the reactor coolant.

The lower side of the inner structure 18 is connected to the core 12 and the upper side of the inner structure 18 is connected to the front side of the pump flow path structure 24 so that the reactor coolant of the reactor vessel 11 is connected to the core 12 to rise along the internal structure 18 and reach the impeller 21 of the reactor coolant pump 20 through the inlet 24a of the pump flow path structure 24.

The core 12 and the steam generator 13 may be partitioned by the inner structure 18 with the inner structure 18 therebetween. The core 12 is received inside the lower portion of the inner structure 18 and the steam generator 13 is positioned higher than the core 12 and disposed outside the inner structure 18. [

The reactor coolant heated from the core 12 can be transferred to the reactor coolant pump 20 while rising along the internal flow path of the internal structure 18 without flowing out to the steam generator 13 located outside the internal structure 18 have.

The coolant discharged by the impeller 21 passes through the discharge portion 24b of the pump flow path structure 24 and flows out between the outer side of the inner structure 18 and the inner wall of the reactor vessel 11, It can flow outward.

The lower side of the inner structure 18 is opened downwardly from the core 12 so that the reactor coolant discharged from the steam generator 13 can be led to the core 12. [

The rotating shaft 23 connects the impeller 21 and the electric motor 25 and transmits the power of the electric motor 25 to the impeller 21. One side of the rotary shaft 23 is disposed inside the reactor vessel 11 and a part of the rotary shaft 23 can be accommodated inside the diffuser 22 and the pump flow path structure 24.

The other side of the rotary shaft 23 is disposed outside the reactor vessel 11 and can be accommodated in the casing 251 of the electric motor 25. [ The rotary shaft 23 can pass through the side surface of the reactor vessel 11 through the connecting nozzle 17. The rotary shaft 23 can be rotatably supported by a bearing 254 provided inside the casing 251.

The electric motor 25 can be used as a power source for driving the impeller 21. [ The electric motor 25 may include a casing 251, a rotary shaft 23, a rotor 252, a stator 253, and the like.

The casing (251) serves as a body of the electric motor (25). A part of the rotary shaft 23, the rotor 252 and the stator 253 can be accommodated in the casing 251. [ The casing 251 may be configured to surround the outside of the stator 253.

The stator 253 and the rotor 252 generate rotational power by electromagnetic interaction. The rotor 252 is disposed inside the stator 253 and can be installed to be rotatable with respect to the stator 253.

The rotor 252 houses a part of the rotating shaft 23 and a bearing 254 is provided between the rotor 252 and the rotating shaft 23 so that the rotor 252 is rotated by the bearing 254 And can be rotatably supported.

A connecting nozzle 17 is formed on the outer wall of the reactor vessel 11 so as to protrude. A penetrating portion is formed inside the connecting nozzle 17, and one side of the casing 251 is inserted into the penetrating portion. The connection nozzle 17 may be formed by thickly forming a part of the reactor vessel 11 in order to enhance the coupling force between the reactor coolant pump 20 and the reactor vessel 11.

The joint portions are formed at the upper and lower portions of the outer side of the casing 251 so that the coupling portions and the connection nozzles 17 of the reactor vessel 11 are fastened by the stud bolts 256, 20 can be firmly fixed to the side surface of the reactor vessel 11.

The other part of the rotary shaft 23 may extend from the casing 251 to the inside of the reactor vessel 11 through a through hole formed in one side of the casing 251. [ At this time, another portion of the rotating shaft 23 housed inside the reactor vessel 11 is surrounded by the diffuser 22, and the end of the rotating shaft 23 is coupled to the impeller 21, Is transmitted to the impeller (21) through the rotary shaft (23).

The discharge portion 24b and the fastening portion (not shown) may be alternately formed in the circumferential direction at the rear end of the pump flow path structure 24. The coupling portion (not shown) is fastened or welded to the casing 251 of the electric motor 25 by a fastening element such as a screw or the like so that the pump flow path structure 24 can be engaged with the casing 251 of the electric motor 25 . The discharge portion 24b is disposed adjacent to the inner wall of the reactor vessel 11 so that the reactor coolant discharged from the diffuser 22 is discharged through the discharge portion 24b between the inner wall of the reactor vessel 11 and the inner structure 18 And the like.

The internal structure 18 may further include a connection portion 18b for connection with a part of the pump flow path structure 24. [ The connection portion 18b may be formed to protrude from the outer surface of the inner structure 18 so as to cover a part of the pump flow path structure 24. [ Portions of the connection portion 18b and the pump flow path structure 24 may be arranged to overlap in a radial direction or a thickness direction. The front end portion of the pump flow path structure 24 may be inserted into the inside of the connection portion 18b of the internal structure 18 and coupled to each other.

At this time, a gap 24c is formed between the connecting portion 18b of the internal structure 18 and the front end portion of the pump flow path structure 24.

Here, the present invention provides a bypass flow reducing section 26. [

The bypass flow reducing portion 26 is provided in a gap 24c formed between the internal structure 18 and the pump flow path structure 24 and is made of elastic material such as a spring 261 or a bellows 262, And seals the gap 24c through a length expansion due to a temperature rise. The reactor coolant discharged from the discharge portion 24b of the pump flow path structure 24 flows into the gap 24c between the internal structure 18 and the pump flow path structure 24 by applying the bypass flow reducing portion 26 So that the inflow can be minimized.

3 may include a spring 261, a sealing member 263, and a guide portion 264. As shown in Fig.

The internal structure 18 of the reactor vessel 11 is provided with an inlet portion 18a formed to communicate with the inlet port 24a of the pump flow path structure 24 and the pump flow path structure 24, respectively.

The inner structure 18 of the reactor vessel 11 is opposed to the front end of the pump flow path structure 24 with the clearance 24c and the connecting portion 18b of the inner structure 18 based on the direction in which the reactor coolant flows, Is configured to surround the pump channel structure (24) with a predetermined clearance (24c) with the outer surface of the front end of the pump channel structure (24).

The spring 261 may be provided in the gap 24c between the front end of the pump flow path structure 24 and the internal structure 18 of the reactor vessel 11. One end of the spring 261 (the rear end of the spring 261 with respect to the flow direction of the reactor coolant) is attached to the pump flow path structure 24 by welding or the like, or attached to the inner structure 18 of the reactor vessel 11 . FIG. 3A shows a state in which one side (right end in the drawing) of the spring 261 is attached to the pump flow path structure 24.

The sealing member 263 is provided in the gap 24c between the internal structure 18 of the reactor vessel 11 and the pump flow path structure 24 and is formed by using the elasticity of the spring 261 or the expansion due to the temperature rise So as to seal the clearance 24c.

The sealing member 263 shown in Fig. 4 may be configured to receive a portion of the spring 261 to take advantage of the elasticity of the spring 261 and / or the length expansion due to the temperature rise.

Specifically, the sealing member 263 may include an outer peripheral surface portion 263b, an inner peripheral surface portion 263a, and a contact portion 263c.

The outer circumferential surface portion 263b is arranged on the outer side of the spring 261 so as to surround the outer side of the spring 261 and the inner circumferential surface portion 263a is arranged on the inner side of the spring 261 so as to surround the inside of the spring 261 Are arranged in the circumferential direction. The sealing member 263 is configured to receive the spring 261 inwardly between the outer circumferential surface portion 263b and the inner circumferential surface portion 263a.

The contact portion 263c is disposed on one side of the outer circumferential surface portion 263b and the inner circumferential surface portion 263a and connects the outer circumferential surface portion 263b and one end portion of the inner circumferential surface portion 263a. The adhered portion 263c may be provided on one side (left end) or the other side (right end) of the outer circumferential surface portion 263b and the inner circumferential surface portion 263a. The sealing member 263 shown in Fig. 4 is provided at the left end portion of the outer circumferential surface portion 263b and the inner circumferential surface portion 263a, and covers the space between the outer circumferential surface portion 263b and the inner circumferential surface portion 263a. An opening is formed on the other side of the outer circumferential surface portion 263b and the inner circumferential surface portion 263a in the direction opposite to the tight contact portion 263c so that the spring 261 is accommodated in the space between the outer circumferential surface portion 263b and the inner circumferential surface portion 263a Can be inserted into the space.

When one side (right end) of the spring 261 is attached to the front end of the pump flow path structure 24 in a state in which the spring 261 is housed inside the sealing member 263, the close contact portion 263c is connected to the spring 261 Of the reactor vessel 11 by the elasticity of the reactor vessel 11 or the expansion of the length due to the temperature rise.

The guide portion 264 is provided at the front end of the pump channel structure 24 and serves to guide the expansion of the spring 261.

The guide portion 264 may be configured to include an inner guide portion 264a and an outer guide portion 264b. The inner guide portion 264a and the outer guide portion 264b are spaced apart from each other with the seal member 263 and the spring 261 interposed therebetween. The inner guide portion 264a surrounds the inner side of the sealing member 263 and the spring 261 and the outer guide portion 264b encloses the outer side of the sealing member 263 and the spring 261. [

The inner guide portion 264a may be formed integrally with the pump flow path structure 24. [ The outer guide portion 264b is provided separately from the pump channel structure 24 so that the outer guide portion 264b and the pump channel structure 24 can be fastened by fastening elements such as screws or by welding.

5, when the electric motor 25 of the reactor coolant pump 20 is operated during the operation of the reactor coolant pump 20, the electromagnetic interactions between the stator 253 and the rotor 252 inside the electric motor 25 The rotor 252 starts to rotate with respect to the stator 253 by the action. The rotating shaft 23 rotates in conjunction with the rotor 252 and the impeller 21 coupled to the front end of the rotating shaft 23 rotates.

As the impeller 21 rotates, a flow of the reactor coolant is formed from the front to the rear of the impeller 21. The impeller 21 sucks the reactor coolant to the diffuser 22 and the diffuser 22 reduces the speed of the sucked fluid and converts it to pressure energy so as to smoothly discharge the fluid through the discharge portion 24b .

The reactor coolant discharged through the discharge portion 24b of the pump flow path structure 24 moves toward the steam generator 13. [

Here, the bypass flow reducing section 26 can seal the gap 24c between the internal structure 18 of the reactor vessel 11 and the pump flow path structure 24 by utilizing elasticity or thermal expansion of the spring 261 . 3 shows a state in which the sealing member 263 is in close contact with the elasticity of the spring 261 when the reactor coolant pump 20 is assembled to the reactor vessel 11. As shown in Fig.

For example, when the reactor coolant pump 20 is assembled to the reactor vessel 11, the sealing member 263 is elastically deformed by the elasticity of the spring 261 by using the elasticity of the spring 261, The gap between the internal structure 18 of the reactor vessel 11 and the pump flow path structure 24 is sealed by being in close contact with the pump flow path structure 24.

Referring again to FIG. 5, both elasticity and thermal expansion of the spring 261 may be utilized. When the reactor coolant pump 20 is assembled to the reactor vessel 11, the sealing member 263 is inserted between the internal structure 18 of the reactor vessel 11 and the pump flow path structure 24 using the elasticity of the spring 261 And the gap 24c can be sealed by making a close contact with each other and utilizing the expansion of the length of the spring 261 due to the temperature rise when the temperature of the reactor coolant rises.

FIG. 6 is a conceptual view showing a state where a reactor coolant pump 20 to which a bypass flow reduction apparatus according to the second embodiment of the present invention is applied is installed in an integrated reactor, FIG. 7 is a schematic view showing the operation of the reactor coolant pump 20 It is a conceptual diagram showing the figure.

The bypass flow reducing section 126 of the present embodiment can be configured by employing the bellows 262 instead of the spring.

In the second embodiment, description of the same components as those in the first embodiment will be omitted, and differences will be mainly described.

The bellows 262 may be in the form of a corrugated tube.

The bellows 262 is provided in a gap 24c between the inner structure 18 of the reactor vessel 11 and the pump flow path structure 24 and is formed by the elasticity and / or thermal expansion of the bellows 262, Can be sealed. 6 shows a state in which the gap 24c is sealed by using the thermal expansion of the bellows 262. As shown in Fig.

One side of the bellows 262 may be attached to the pump flow path structure 24 or attached to the internal structure 18 of the reactor vessel 11. 6 shows a state in which one side of the bellows 262 is attached to the internal structure 18 of the reactor vessel 11.

6 and 7, the other side of the bellows 262 is slightly apart from the step of assembling the reactor coolant pump 20 to the reactor vessel 11 (see FIG. 6), and when the temperature of the reactor coolant rises The bellows 262 can seal the gap 24c by closely contacting the internal structure 18 of the reactor vessel 11 due to the expansion of the bellows 262 due to the temperature rise. The other side of the bellows 262, that is, the right end of the bellows 262, may be attached to the pump flow path structure 24 by welding or the like. The outer guiding portion 264b of the guiding portion 264 can be removed.

8 is a conceptual diagram showing a state in which a reactor coolant pump 20 to which a bypass flow reduction apparatus 226 according to the third embodiment of the present invention is applied is installed in an integrated reactor.

Since the present embodiment is the same as or similar to the first embodiment shown in FIG. 3, duplicated description will be omitted.

3, the gap 24c between the inner structure 18 of the reactor vessel 11 and the pump flow path structure 24 is sealed by using the thermal expansion of the spring 261, unlike the first embodiment of FIG. .

The bypass flow reducing portion 226 shown in FIG. 8 is slightly spaced apart from the step of assembling the reactor coolant pump 20 to the reactor vessel 11, and the spring 261 due to the temperature rise when the temperature of the reactor coolant rises. The sealing member 263 closely contacts the gap 24c between the internal structure 18 of the reactor vessel 11 and the pump flow path structure 24 to seal the gap 24c.

9 is a conceptual diagram showing a state in which a reactor coolant pump 20 to which a bypass flow reduction apparatus 326 according to the fourth embodiment of the present invention is applied is installed in an integrated reactor.

Since the present embodiment is the same as or similar to the second embodiment shown in FIG. 6, a duplicate description will be omitted.

The present embodiment is a structure for sealing the gap 24c between the internal structure 18 of the reactor vessel 11 and the pump flow path structure 24 by using the elasticity of the bellows 262. [

The bypass flow reducing portion 326 shown in FIG. 9 uses the elasticity of the bellows 262 when the reactor coolant pump 20 is assembled to the reactor vessel 11 so that the bellows 262 is inserted into the inside of the reactor vessel 11 Tightly between the structure 18 and the pump flow path structure 24 to seal the gap 24c.

The bellows 262 may also be configured to allow the bellows 262 to move relative to the inner structure 18 of the reactor vessel 11 and the pump 262 using the resiliency of the bellows 262 when the reactor coolant pump 20 is assembled to the reactor vessel 11. [ And the gap 24c may be sealed by making a close contact with the flow path structure 24 and making a secondary contact with the expansion of the bellows 262 when the temperature of the reactor coolant rises.

10 is a conceptual diagram showing a state in which a reactor coolant pump 20 to which a bypass flow reducing apparatus 426 according to a fifth embodiment of the present invention is applied is installed in an integrated reactor 10. FIG.

Since the present embodiment is the same as or similar to the first embodiment shown in FIG. 3, duplicated description will be omitted.

In this embodiment, however, the outer wall guide portion 264b of the guide portion 264 is removed, but the sealing member 263 is formed by the elasticity of the spring 261 and the inner structure 18 of the reactor vessel 11 The gap between the internal structure 18 of the reactor vessel 11 and the gap 24c between the pump flow path structure 24 can be sealed.

11 is a conceptual diagram showing a state in which a reactor coolant pump 20 to which a bypass flow reducing apparatus 526 according to a sixth embodiment of the present invention is applied is installed in the integrated reactor 10. [

Since the present embodiment is the same as or similar to the second embodiment shown in FIG. 6, a duplicate description will be omitted.

However, in this embodiment, the inner guide portion 264a of the guide portion 264 and the outer guide portion 264b are provided to guide the expansion of the bellows 262 in a state where one side of the bellows 262 is fixed. can do. The outer guiding portion 264b can be fastened to the pump channel structure 24 by a fastening element such as a screw or by welding.

Also, in this embodiment, the sealing member 263 encloses the inside and the outside of the bellows 262, and the bellows 262 can be received inside. The sealing member 263 includes an inner circumferential surface portion 263a surrounding the inner side of the bellows 262, an outer circumferential surface portion 263b surrounding the outer side of the bellows 262, and an inner circumferential surface portion 263b connecting the inner circumferential surface portion 263a and the outer circumferential surface portion 263b, And a tight fitting portion 263c that is brought into close contact with the inner structure 18 of the reactor vessel 11 by utilizing the expansion of the length of the reactor vessel 262.

The sealing member 263 is slightly spaced from the internal structure 18 of the reactor vessel 11 when the reactor coolant pump 20 is assembled to the reactor vessel 11 and the bellows 262 The sealing member 263 is brought into close contact with the inner structure 18 of the reactor vessel 11 and the pump flow path structure 24 by the expansion of the length of the inner wall of the reactor vessel 11, The gap 24c between the pump flow path structures 24 can be sealed.

12 is a conceptual diagram showing a state in which a reactor coolant pump 20 to which a bypass flow reducing apparatus 626 according to a seventh embodiment of the present invention is applied is installed in an integrated reactor 10.

The bypass flow reducing section 626 according to the present embodiment forms a sealing structure in which the bellows 262 and the sealing member 263 are integrally formed.

For example, the sealing member 262b is integrally formed at the front end portion of the bellows 262. [ The fastening portion 262a is integrally formed at the rear end of the bellows 262 so that the bellows 262 can be attached to the pump flow path structure 24 through the fastening portion 262a. The fastening portion 262a can be welded to the front end of the pump channel structure 24.

In this embodiment, the outer guiding portion 264b of the guiding portion 264 can be eliminated.

The sealing member 262b can seal the gap 24c between the internal structure 18 of the reactor vessel 11 and the pump flow path structure 24 by utilizing the thermal expansion of the bellows 262. [

The sealing member 262b) is slightly spaced from the internal structure 18 of the reactor vessel 11 when the reactor coolant pump 20 is assembled to the reactor vessel 11 and the bellows The sealing member 262b advances due to the expansion of the length of the reactor vessel 11 due to the temperature increase of the reactor vessel 262 and is brought into close contact with the inner structure 18 of the reactor vessel 11 and the pump flow path structure 24, 18 and the pump flow path structure 24 can be sealed.

FIG. 13 is a conceptual diagram showing a state in which a reactor coolant pump 20 to which a bypass flow reduction apparatus 726 according to an eighth embodiment of the present invention is applied is installed in an integrated reactor 10. FIG.

The bypass flow reducing apparatus according to the present embodiment forms a sealing structure in which the spring 261 and the sealing member 261b are integrally formed.

For example, the sealing member 261b is integrally formed at the front end portion of the spring 261. [ The fastening portion is integrally formed at the rear end of the spring 261 so that the spring 261 can be attached to the pump flow path structure 24 through the fastening portion 261a. The fastening portion 261a of the spring 261 can be welded to the front end of the pump channel structure 24.

In this embodiment, the outer guiding portion 264b of the guiding portion 264 can be eliminated.

The sealing member 261b can seal the gap 24c between the internal structure 18 of the reactor vessel 11 and the pump flow path structure 24 by utilizing the thermal expansion of the spring 261. [

That is, the sealing member 261b is slightly spaced from the internal structure 18 of the reactor vessel 11 when the reactor coolant pump 20 is assembled to the reactor vessel 11, and when the temperature of the reactor coolant rises, The sealing member 261b advances due to the expansion of the temperature of the reactor vessel 11 and the internal structure 18 of the reactor vessel 11 so as to be in close contact with the internal structure 18 of the reactor vessel 11 and the pump flow path structure 24 And the pump flow path structure 24 can be sealed.

As described above, the bypass flow reducing section 26 is provided with a spring 261 (see Figs. 3, 5 and 10) inside the sealing member 263, and a configuration including only the bellows 262 6, 7 and 9), a configuration in which the bellows 262 is housed in the sealing member 263 (see FIG. 11), the sealing member 262b and the bellows 262 are integrally formed (FIGS. (See Figs. 13, 14, 15 and 17), in the case of a seal (not shown) such as a "disk spring washer" And the like.

14 is a conceptual diagram showing a state in which a reactor coolant pump 20 to which a bypass flow reducing apparatus 826 according to a ninth embodiment of the present invention is applied is installed in an integrated reactor 10. FIG.

In this embodiment, the bypass flow reducing portion 826 can form a sealing structure in a form attached to the internal structure 18 of the reactor vessel 11.

For example, one side of the integral spring 261 of the sealing member 261b may be attached to the inner structure 18 of the reactor vessel 11. The sealing member 261b shown in Fig. 14 is integrally formed at the rear end of the spring 261 (with reference to the moving direction of the fluid), and the fastening portion is formed at the front end of the spring 261. [ The fastening portion 261a can fasten the front end portion of the spring 261 and the internal structure 18 of the reactor vessel 11 by welding.

In the present embodiment, the sealing member 263 can form a sealing structure by utilizing the thermal expansion of the integral spring 261. [

The sealing member 261b is spaced a little from the front end of the pump flow path structure 24 when the reactor coolant pump 20 is assembled into the reactor vessel 11 and is expanded to a length due to temperature rise when the temperature of the reactor coolant rises The gap between the pump flow path structure 24 and the internal structure 18 of the reactor vessel 11 is sealed to seal the gap 24c between the pump flow path structure 24 and the internal structure 18 of the reactor vessel 11.

The connecting portion 18b of the inner structure 18 of the reactor vessel 11 serves as the guiding portion 264 and the length of the integral spring 261 of the sealing member 263 It can guide the expansion.

15 is a conceptual diagram showing a bypass flow reducing apparatus 926 according to a tenth embodiment of the present invention.

The bypass flow reducing device 926 according to the present embodiment can be configured as the integral spring 261 of the sealing member 261b. A sealing member 261b is integrally formed at the upper end of the spring 261 and a fastening portion 261a is integrally formed at the lower end of the spring 261. [ The fastening portion 261a is a portion for fastening the spring 261 to the pump flow path structure 24 or the internal structure 18 of the reactor vessel 11 with the integral spring 261. [

An incision 261b 'may be disposed in a part of the sealing member 261b so as to be spaced apart in the circumferential direction.

The cutout portion 261b 'may be cut in the longitudinal direction of the sealing member 261b (in the vertical direction in the right-hand view of FIG. 15). However, a portion of the sealing member 261b is cut so that the sealing member 261b is not broken by the cutout portion 261b '.

The cutout portion 261b'is relatively protruded from the protruding portion when the surface of the internal structure 18 of the reactor vessel 11 to which the sealing member 261b is to be contacted or the surface of the pump flow path structure 24 is bent. The sealing member 261b may be pushed inward or open outward so that the sealing member 261b is uniformly brought into close contact with all of the non-sealed portions.

In the absence of the cutout 261b ', the sealing member 261b may be in close contact with the protruding portion of the inner structure 18 of the reactor vessel 11 and not in the portion that is not relatively protruding.

However, when the cut-out portion 261b 'is formed, the sealing member 261b is pushed to the inside of the sealing member 261b or opened outward due to the elasticity of the spring 261 or the length expansion due to the temperature rise, Is in close contact with the protruding portion of the inner structure (18) of the housing (11). Also, the sealing member 261b can be brought into close contact with the relatively non-protruding portion of the internal structure 18. [

16 is a conceptual diagram showing a bypass flow reducing apparatus 1026 according to the eleventh embodiment of the present invention.

The bypass flow reducing section 1026 according to the present embodiment includes a sealing member 262b integrally formed on the upper end of the bellows 262 and a plurality of cutouts 262b arranged in the circumferential spacing in the sealing member 262b ').

The cutout portion 262b 'is formed in a part of the sealing member 262b so that the sealing member 262b is not sliced. The sealing member 262b can be pushed into the inside of the sealing member 262b by the cutout portion 262b 'or can be spread outward.

The sealing member 262b formed with the cut-out portion 262b 'is pushed to the inside of the sealing member 262b or opened outward due to the elasticity of the bellows 262 or the expansion due to the temperature rise, As well as the protruding portions of the inner structure 18 of the first and second protrusions.

17 is a conceptual diagram showing a bypass flow reducing apparatus 1126 according to a twelfth embodiment of the present invention.

The bypass flow reducing portion 1126 according to the present embodiment includes a sealing member 261b integrally formed at an upper end portion of a spring 261 and a plurality of cut portions 261b arranged to be spaced apart from each other in the circumferential direction of the sealing member 261b Quot;).

The ends of the sealing member 261b may be cut by the plurality of cutouts 261b ", and alternately arranged in the circumferential direction and staggered from each other. For example, the end of the sealing member 261b may be alternately The sealing member 261b can be formed so as to protrude toward the inside of the sealing member 261b through elasticity of the spring 261 or expansion of the length due to temperature rise, It can be pinched or widened outwardly.

18 is a conceptual diagram showing a bypass flow reduction device 1226 according to the thirteenth embodiment of the present invention.

The bypass flow reducing portion 1226 according to the present embodiment includes a sealing member 262b integrally formed on the upper end of the bellows 262 and a plurality of cut portions 262b arranged to be spaced apart from each other in the circumferential direction of the sealing member 262b Quot;).

The ends of the sealing member 262b may be cut by the plurality of cutouts 262b "to be alternated in the circumferential direction and staggered from each other. For example, the end of the sealing member 262b may be alternately The sealing member 262b can be formed so as to protrude toward the inner side of the sealing member 262b through elasticity of the bellows 262 or expansion of the length due to temperature rise, Or may be spread outwardly.

19 to 24 are conceptual diagrams showing the shapes of various springs 261 and bellows 262 according to the embodiment of the present invention.

The spring 261 shown in Fig. 19 is a helical disk spring. The spring 261 may mean that a strand 2611 of circular or elliptical cross-sectional shape extends in the spiral direction on a cylindrical circumference having a constant diameter. The helical disk spring 261 may have a shape in which a strand 2611 having an elliptical cross-sectional shape extends along the spiral direction.

The spring 261 shown in Fig. 20 is a disk spring washer. The disk spring washer may have a shape in which two stranded strands 2612 having a rectangular cross-sectional shape extend along the spiral direction.

In the spring 261 shown in FIG. 21, the volute spring may have a shape in which a strand 2613 having a flat cross-sectional shape extends along the spiral direction.

The spring 261 shown in Fig. 22 is a coil spring. The coil spring 261 may have a shape in which a strand 2614 having a circular sectional shape on a cylindrical circumference extends in a spiral direction.

The spring 261 shown in Fig. 23 is an integral spring 261 of the sealing member 261b. 23, a sealing member 261b is integrally formed at the left end of the spring 261, a fastening portion 261a is formed at the right end of the spring 261, and a plurality of fastening holes 261a are formed in the fastening portion 261a And can be formed to be spaced apart in the circumferential direction.

The bellows 262 shown in Fig. 24 is an integral bellows 262 of the sealing member 262b. 24, a sealing member 262b is integrally formed at the front end portion of the bellows 262 and a fastening portion 261a is integrally formed at the rear end portion of the bellows 262. [

According to the present invention, the bypass flow reducing portions 26, 126, 226, 326, 426, 526, 626, 726, 826 are provided in the gap 24c between the internal structure 18 of the reactor vessel 11 and the pump flow path structure 24, and the spring 261 or bellows The seal member 263 is brought into close contact with the inner structure 18 of the reactor vessel 11 and the pump flow path structure 24 by using at least one of the elasticity of the reactor vessel 262 and the expansion of the length of the reactor vessel 11 The gap 24c between the inner structure 18 of the pump channel structure 24 and the pump channel structure 24 can be sealed.

In addition, by sealing the gap 24c between the internal structure 18 of the reactor vessel 11 and the pump flow path structure 24, it is possible to shut off the bypass flow generated due to the flow into the gap 24c.

In addition, as the bypass flow to the gap 24c formed between the reactor coolant pump 20 and the reactor internal structure in the integrated reactor 10 is minimized, the circulating flow rate of the reactor coolant circulated by the reactor coolant pump 20 And can be used efficiently.

In addition, as the circulation flow rate of the reactor coolant increases, the thermal margin of the core 12 can be increased to enhance the safety of the nuclear power plant.

In addition, as the bypass flow rate of the reactor coolant not participating in the cooling of the reactor is reduced, the capacity of the reactor coolant pump 20 can be efficiently reduced while maintaining the cooling performance of the reactor coolant system, and the reactor coolant pump 20 can be miniaturized And the economic efficiency of the nuclear power plant can be improved.

It will be apparent to those skilled in the art that various modifications, substitutions and alterations can be made hereto without departing from the spirit and scope of the invention as defined by the appended claims. will be.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed. .

The scope of protection of the present invention should be construed according to the following claims, and all technical ideas within the scope of equivalents should be interpreted as being included in the scope of the present invention.

10: Integrated reactor 11: Reactor vessel
12: core 13: steam generator
14: main water supply line 15: main engine
16: pressurizer 17: connection nozzle
18: internal structure 18a:
18b: connection 20: reactor coolant pump
21: impeller 22: diffuser
23: rotating shaft 24: pump channel structure
24a: Inlet port 24b:
24c: clearance 25: electric motor
251: casing 252: rotor
253: stator 254: bearing
255: engaging portion 256: stud bolt
26,126,226,326,426,526,626,726,826: Bypass flow reduction unit
261: spring 261a:
261b: Sealing members 261b ', 261b "
262: bellows 262a: fastening portion
262b: sealing member 262b ', 262b ": cut-
263: sealing member 263a: inner peripheral surface portion
263b: outer peripheral surface portion 263c:
263d: opening 264:
264a: inner guide portion 264b: outer guide portion

Claims (17)

An electric motor mounted on an outer wall side of the reactor vessel;
An impeller which is accommodated in the reactor vessel and receives power from the motor to circulate the reactor coolant inside the reactor vessel;
Wherein the reactor coolant discharged from the discharge portion of the pump flow path structure is disposed in the gap between the internal structure of the reactor vessel and the pump flow path structure surrounding the impeller so that both sides thereof are in contact with the internal structure and the pump flow path structure, A bypass flow reduction unit that reduces the bypass flow rate of the reactor coolant flowing back into the impeller through the gap;
Lt; / RTI >
Wherein the bypass flow-
When the reactor coolant pump is assembled, the gap is sealed by elasticity while being compressed by the internal structure and the pump flow path structure,
As the length of the reactor coolant increases, the both sides are closely contacted with the internal structure and the pump flow path structure to seal the gap,
Wherein the gap is sealed by elasticity while being compressed by the internal structure and the pump flow path structure when the reactor coolant pump is assembled, and when the temperature of the reactor coolant is increased, the length is expanded and compressed, Thereby maintaining the seal as it is absorbed. The method according to claim 1,
Wherein the bypass flow-
A bellows or a spring. The method according to claim 1,
Wherein the bypass flow-
Wherein one side is fixed to the pump channel structure and the other side is expanded to an internal structure of the reactor vessel. The method according to claim 1,
Wherein the bypass flow-
Wherein one side is fixed to the inner structure of the reactor vessel and the other side is expanded in length to the pump channel structure. 3. The method of claim 2,
Wherein the bypass flow-
Further comprising a sealing member formed integrally with the bellows and moved by the expansion of the bellows to closely contact the internal structure of the reactor vessel or the pump flow path structure. 3. The method of claim 2,
Wherein the bypass flow-
Further comprising a sealing member formed integrally with the spring, the sealing member being moved by the expansion of the spring to closely contact the internal structure of the reactor vessel or the pump flow path structure. 3. The method of claim 2,
Wherein the bypass flow-
Further comprising a sealing member which receives a part of the spring to cover an outer side and an inner side of the spring and is moved by the expansion of the spring to closely contact the inner structure of the reactor vessel or the pump flow path structure, Coolant pump. 3. The method of claim 2,
Wherein the bypass flow-
And a guide portion provided in the pump channel structure to guide a length expansion of the spring,
The guide portion
An inner guide portion surrounding the inside of the spring; And
And at least one guiding portion of the outer guiding portion surrounding the outside of the spring. 3. The method of claim 2,
Wherein the bypass flow-
And a guide portion provided in the pump channel structure to guide a length expansion of the bellows,
The guide portion
An inner guide portion surrounding the inside of the bellows; And
And at least one guiding portion of the outer guiding portion surrounding the outside of the bellows. 3. The method of claim 2,
Wherein the bypass flow reducing portion is fastened by a screw or welding. 3. The method of claim 2,
Wherein the spring is one of a coil spring, a disk spring, and a volute spring. 6. The method of claim 5,
Wherein the sealing member is integrally formed at a front end of the bellows, and an incision portion in which the end of the sealing member is partially cut is disposed so as to be spaced apart in the circumferential direction, and an end portion of the sealing member is radially inwardly Or open to the outside of the reactor coolant pump. The method according to claim 6,
Wherein the sealing member is integrally formed at the front end of the spring and the incision portion in which the end of the sealing member is partially cut is disposed so as to be spaced apart in the circumferential direction so that the end portion of the sealing member is radially inward of the sealing member Or open to the outside of the reactor coolant pump. The method according to claim 12 or 13,
Wherein the end portions of the sealing member are alternately arranged alternately in the circumferential direction by the cutout portions and alternately pushed or spread radially inwardly and outwardly of the sealing member. The method according to claim 1,
The motor includes:
A stator and a rotor for generating a rotational force by electromagnetic interaction;
A rotary shaft having one side connected to the rotor and the other side projecting to the inside of the reactor vessel and connected to the impeller; And
A casing protruding outward from an outer wall side of the reactor vessel and surrounding the stator and the rotor and a part of the rotation shaft;
And a reactor coolant pump. 16. The method of claim 15,
Wherein the rotating shaft is disposed to extend in the radial direction of the reactor vessel. A reactor vessel accommodating therein a core, a steam generator, and a pressurizer;
A reactor coolant pump for circulating the reactor coolant stored in the reactor vessel, the reactor coolant pump including an impeller rotatably accommodated in the reactor vessel and an electric motor rotating the impeller;
A pump channel structure accommodated in the reactor vessel and surrounding a periphery of the impeller and discharging the reactor coolant discharged by the impeller to the steam generator;
An internal structure provided inside the reactor vessel for guiding the reactor coolant from the core to a front end of the impeller; And
And a spring or a bellows disposed between the pump flow path structure and the internal structure so that both sides thereof can be in contact with the pump flow path structure and the internal structure, respectively, and the reactor coolant discharged from the discharge portion of the pump flow path structure, A bypass flow reduction unit for reducing the bypass flow rate of the bypass coolant flowing into the impeller through a gap between the internal structures;
Lt; / RTI >
Wherein the bypass flow-
When the reactor coolant pump is assembled, the gap is sealed by elasticity while being compressed by the internal structure and the pump flow path structure,
As the length of the reactor coolant increases, the both sides are closely contacted with the internal structure and the pump flow path structure to seal the gap,
Wherein the gap is sealed by elasticity while being compressed by the internal structure and the pump flow path structure when the reactor coolant pump is assembled, and when the temperature of the reactor coolant is increased, the length is expanded and compressed, Thereby maintaining the seal as it is absorbed.

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