WO2021248388A1 - Nuclear fuel assembly loading/unloading container and method for loading/unloading nuclear fuel assembly - Google Patents

Abstract

A nuclear fuel assembly loading/unloading container and a method for loading/unloading a nuclear fuel assembly. The nuclear fuel loading/unloading container comprises a shielding cylinder (10) provided therein with a fuel accommodating cavity (100) for accommodating a fuel assembly and cooling water, a grabbing mechanism (20) provided within the fuel accommodating cavity (100), a support base (30) provided above the shielding cylinder (10), a lifting/lowering mechanism (40) provided on the support base (30), and an opening/closing mechanism (50) provided at the bottom of the shielding cylinder (10). The lifting/lowering mechanism (40) is connected to and drives the grabbing mechanism (20) to move vertically back and forth in the axial direction of the fuel accommodating cavity (100). An opening in communication with the fuel accommodating cavity (100) is provided at the bottom of the shielding cylinder (10). The opening/closing mechanism (50) opens or closes the opening. The lifting/lowering mechanism (40) is located above the shielding cylinder (10). The nuclear fuel assembly loading/unloading container and the method for loading/unloading the nuclear fuel assembly implement the loading, unloading, and transfer of the nuclear fuel assembly, the loading/unloading container is provided with a semi-closed space closed at the bottom and opened at the top when transferring the fuel assembly, thus reducing the requirement on sealing performance and reducing the difficulty of sealing. The lifting/lowering mechanism does not need to be submerged in the cooling water, thus reducing waterproof performance and avoiding the problem of maintenance difficulty brought forth by contamination.

Description

Nuclear fuel assembly loading and unloading container and nuclear fuel assembly loading and unloading method Technical field

The invention relates to the technical field of reactor nuclear fuel loading and unloading, in particular to a nuclear fuel assembly loading and unloading container and a nuclear fuel assembly loading and unloading method.

Background technique

When refueling is carried out on a marine reactor, the fuel assembly needs to be transported off the surface of the water. When the fuel assembly is transported off the water surface, the radiation protection problem needs to be solved, and the fuel assembly needs to be cooled at the same time. Most of the existing equipment is used for underwater transportation of fuel assemblies, and some are used for water transportation of fuel assemblies. Current equipment used for water transport, such as Chinese patent CN205487370U, discloses a fuel assembly refueling device, which is a fully enclosed space and requires high sealing performance. In addition, it involves temperature changes and dynamic sealing, which further increase the difficulty of sealing; The lifting mechanism is in cooling water, which requires high waterproof performance for electric control components such as motors; the lifting mechanism is in a closed water environment, and the equipment is contaminated and difficult to repair. The fuel assembly needs to be immersed in water when grabbing the fuel assembly, and the bottom of the fuel assembly needs to be cleaned and decontaminated each time the fuel assembly is grabbed.

technical problem

The technical problem to be solved by the present invention is to provide a nuclear fuel assembly loading and unloading container and a nuclear fuel assembly loading and unloading method in view of the above-mentioned defects in the prior art.

Technical solutions

The technical solution adopted by the present invention to solve its technical problem is to provide a nuclear fuel assembly loading and unloading container, which includes a shielding cylinder with a fuel cavity for accommodating the fuel assembly and cooling water; A grabbing mechanism for grabbing and placing fuel assemblies, a support seat provided above the shielding cylinder, a lifting mechanism provided on the support seat, and an opening and closing mechanism provided at the bottom of the shielding cylinder;

The lifting mechanism is connected to and drives the grasping mechanism to move up and down along the axial direction of the fuel cavity; the bottom of the shielding cylinder is provided with an opening communicating with the fuel cavity for fuel assembly to pass in and out; The opening and closing mechanism closes or opens the opening.

Preferably, the lifting mechanism includes a lifting drum wound with a steel wire rope, a motor, and a reducer;

The support seat is provided with a through hole communicating with the fuel cavity; the steel wire rope on the lifting drum enters the fuel cavity through the through hole, and is connected to the grasping mechanism;

The motor and the reducer are connected and drive the lifting drum to rotate to retract the steel wire rope, and drive the grabbing mechanism to move up and down.

Preferably, the lifting mechanism further includes a weighing mechanism that monitors the weight of the grasping mechanism to determine whether to grasp the fuel assembly; the weighing mechanism and the lifting drum are located on the support seat. The opposite sides of the fuel cavity;

After the steel wire rope passes through the grabbing mechanism in the fuel cavity, its end extends out of the fuel cavity and is connected to the weighing mechanism.

Preferably, the weighing mechanism includes a supporting beam fixed on the supporting base, a connecting plate that is vertically suspended on the supporting beam relative to the supporting beam, and a weighing probe arranged on the connecting plate;

The end of the steel wire rope protruding from the fuel cavity is connected to the connecting plate.

Preferably, the lifting mechanism further comprises a safety brake connected to the lifting drum; and/or, the lifting mechanism further comprises an emergency hand wheel connected to the motor and the reducer.

Preferably, the grasping mechanism includes a support frame, a pulley assembly arranged at the upper end of the support frame, a gripper arranged at the lower end of the support frame that can be opened and closed to grasp and release the fuel assembly, and is arranged in the support frame and Connected to a driving device that drives the opening and closing of the gripper;

The steel wire rope of the lifting mechanism wraps the pulley assembly and is connected to drive the grasping mechanism to move up and down.

Preferably, the driving device is an air cylinder; the grasping mechanism further includes a trachea reel with a trachea wound on the support seat, and the trachea reel can rotate to retract and retract the trachea;

The air pipe is released from the air pipe reel and connected to the air cylinder, and an external air source drives the air cylinder to move.

Preferably, the grasping mechanism further includes a limit switch arranged on the supporting frame and located on one side of the driving device, and a cable reel with a cable wound on the supporting base;

The cable reel can rotate to take up and take up the cable; the cable is released from the cable reel and connected to the limit switch.

Preferably, the grasping mechanism further includes an encoder assembly arranged on the support base for measuring the vertical position of the grasping mechanism in the fuel cavity.

Preferably, the top of the shielding cylinder is provided with a first flange for connecting with the support base; the bottom of the shielding cylinder is provided with a second flange for connecting with the opening and closing mechanism.

Preferably, the inner wall surface of the fuel containing cavity is provided with a guiding structure extending along the axial direction of the fuel containing cavity and slidingly fitted with the grasping mechanism.

Preferably, the shielding cylinder includes an inner cylinder, an outer cylinder sleeved outside the inner cylinder, and a shielding layer provided between the inner cylinder and the outer cylinder; the inside of the inner cylinder The space forms the fuel cavity.

Preferably, the opening and closing mechanism includes a valve body, a ball rotatably arranged in the valve body, a valve stem that passes through the valve body and connects to the ball, and a drive motor that connects and drives the valve stem to rotate;

The valve body is provided with a valve body passage that penetrates opposite ends of the valve body and communicates with the opening; the ball is provided with a sphere passage that can communicate with the valve body passage;

When the sphere is in the first position, the sphere passage and the valve body passage are connected in parallel to open the opening of the shielding cylinder;

When the sphere is in the second position, the sphere passage and the valve passage are staggered to close the opening of the shielding cylinder.

Preferably, the nuclear fuel assembly loading and unloading container further includes a water inlet pipe which is arranged in the fuel cavity and delivers cooling water to the fuel cavity; the water inlet end of the water inlet pipe extends above the shielding cylinder Take an external cooling water circulation system.

Preferably, the nuclear fuel assembly loading and unloading container further includes a water outlet pipe which is arranged in the fuel cavity and draws out the cooling water in the fuel cavity; the water outlet end of the water outlet pipe extends above the shielding cylinder The external cooling water circulation system forms a cooling water circulation loop with the cooling water circulation system and the water inlet pipe.

Preferably, the nuclear fuel assembly loading and unloading container further includes a wall surrounding the outer periphery of the support base.

Preferably, the nuclear fuel assembly loading and unloading container further includes a spreader connected to the outer side of the shielding cylinder.

The present invention also provides a method for loading and unloading a nuclear fuel assembly, which includes the following steps:

S1. Lifting and positioning the nuclear fuel assembly loading and unloading container of any one of claims 1-17 at the fuel assembly storage place or above the core;

S2, the opening and closing mechanism of the nuclear fuel assembly loading and unloading container operates to open the opening of the shielding cylinder;

S3. The lifting mechanism above the shielding cylinder acts to drive the grabbing mechanism in the fuel cavity of the shielding cylinder to descend onto the fuel assembly;

S4. The grabbing mechanism grabs the fuel assembly, and the lifting mechanism acts to drive the grabbing mechanism up to transport the grabbed fuel assembly into the fuel cavity;

S5. The opening and closing mechanism closes the opening.

Preferably, the loading and unloading method further includes the following steps:

S6. Inject cooling water into the fuel cavity to submerge the fuel assembly.

Preferably, the loading and unloading method further includes the following steps:

S7. The crane lifts the nuclear fuel assembly loading and unloading container with the fuel assembly to the designated location;

S8. The opening and closing mechanism acts to open the opening of the shielding cylinder and discharge the cooling water;

S9. The lifting mechanism acts to drive the grabbing mechanism down, lowering the grabbed fuel assembly to a specified height, and the grabbing mechanism releases the fuel assembly;

S10. The lifting mechanism acts to drive the grabbing mechanism to rise into the fuel cavity, and the opening and closing mechanism closes the opening.

Beneficial effect

In the nuclear fuel assembly loading and unloading container of the present invention, the lifting mechanism outside the shielding cylinder cooperates with the grabbing mechanism inside the shielding cylinder to realize the loading, unloading and transferring of the fuel assembly; wherein the lifting mechanism is arranged above the shielding cylinder through the support seat, and cooperates with the opening and closing mechanism in the shielding The arrangement of the bottom of the cylinder makes the loading and unloading container form a semi-closed space with a closed bottom and an open top when transferring the fuel assembly, which reduces the requirements for sealing performance, thereby reducing the difficulty of sealing; in addition, the lifting mechanism and other related electronic control devices are in the shielding cylinder. The setting outside the body does not need to be immersed in the cooling water inside the shielding cylinder, which reduces the waterproof performance of the electronic control device and avoids the problem of difficult maintenance caused by contamination.

Description of the drawings

The present invention will be further described below in conjunction with the accompanying drawings and embodiments. In the accompanying drawings:

Fig. 1 is a schematic diagram of a three-dimensional structure of a nuclear fuel assembly loading and unloading container according to an embodiment of the present invention;

2 is a schematic cross-sectional structure diagram of a nuclear fuel assembly loading and unloading container according to an embodiment of the present invention;

FIG. 3 is a schematic diagram of the structure of the lifting mechanism and the lifting mechanism in FIG. 2;

Fig. 4 is a schematic structural diagram of the lifting mechanism and the lifting mechanism in Fig. 2 at another angle;

Fig. 5 is a top view of the support base and its upper lifting mechanism in Fig. 2.

Embodiments of the present invention

In order to have a clearer understanding of the technical features, objectives and effects of the present invention, the specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

As shown in FIGS. 1 and 2, the nuclear fuel assembly loading and unloading container according to an embodiment of the present invention includes a shielding cylinder 10, a grasping mechanism 20, a support base 30, a lifting mechanism 40, and an opening and closing mechanism 50.

The shield cylinder 10 has a fuel accommodating cavity 100 for accommodating the fuel assembly, and also for accommodating cooling water to cool the fuel assembly. An opening is provided at the bottom of the shield cylinder 10 to communicate with the fuel cavity 100 for the fuel assembly to enter and exit the fuel cavity 100. The grasping mechanism 20 is arranged in the fuel cavity 100 and can move up and down along the axial direction of the fuel cavity 100. The grasping mechanism 20 is used for grasping and placing the fuel assembly. The support base 30 is arranged above the shield cylinder 10 (also can be understood as the top), and is located outside the fuel cavity 100. The lifting mechanism 40 is arranged on the support base 30, and is connected to and drives the grasping mechanism 20 to move up and down along the axial direction of the fuel cavity 100. The opening and closing mechanism 50 is provided at the bottom of the shielding cylinder 10 to close or open the opening.

Among them, structurally, the shielding cylinder 10 may include an inner cylinder 11, an outer cylinder 12 sheathed outside the inner cylinder 11, and a shielding layer 13 arranged between the inner cylinder 11 and the outer cylinder 12. The inner space of the inner cylinder 11 forms a fuel cavity 100. In the shielding cylinder 10, the shielding layer 13 is the main body of the radiation shielding of the fuel assembly; the outer cylinder 12 and the inner cylinder 11 realize the envelope and support of the shielding layer 13.

In order to be connected to the support base 30, a first flange 14 is provided on the top of the shielding cylinder 10, and the support base 30 is fitted on the first flange 14 and is fixedly connected to the first flange 14 by fasteners or the like. The bottom of the shielding cylinder 10 is provided with a second flange 15 for connecting with the opening and closing mechanism 50. Both the first flange 14 and the second flange 15 are provided with a central through hole to communicate with the fuel cavity 100.

In the fuel cavity 100 of the shield cylinder 10, the grabbing mechanism 20 can move up and down along the fuel cavity 100 to deliver the grabbed fuel assembly into the fuel cavity 100 or out of the fuel cavity 100. In order to make the grasping mechanism 20 move back and forth stably along the axial direction of the fuel chamber 200, the inner wall surface of the fuel chamber 100 (that is, the inner wall surface of the inner cylinder 11) is provided with an axial extension of the fuel chamber 100. The guiding structure 16 is slidingly matched with the grasping mechanism 20.

The support base 30 is fixed above the shielding cylinder 10 through the first flange 14. The support base 30 is provided with a through hole communicating with the fuel chamber 100, and the lifting mechanism 40 is connected to the grasping mechanism 20 through the through hole, so that the top of the shielding cylinder 10 is not closed, and the bottom opening is closed and a semi-closed state is formed.

As shown in FIGS. 3-5, the grasping mechanism 20 may include a supporting frame 21, a grab 22 arranged at the lower end of the supporting frame 21, and a driving device 23 arranged in the supporting frame 21. The gripper 22 can be opened and closed for grasping and releasing the fuel assembly; the driving device 23 is connected to and drives the gripper 22 to open and close. The lifting mechanism 40 is connected with and drives the support frame 21 to move up and down to drive the gripper 22 and the fuel assembly grasped by it to move up and down.

The guide structure 16 in the fuel cavity 100 is mainly in sliding fit with the support frame 21, and is set according to the support frame 21. For example, for the support frame 21 with a rectangular cross-section, the guide structure 16 may include two long strips arranged at intervals to interfere with at least one corner of the support frame 21 to restrict the rotation of the support frame 21.

Alternatively, the driving device 23 is an air cylinder. The grasping mechanism 20 also includes a rotatable tracheal reel 24 arranged on the support base 30, and a trachea is wound on the tracheal reel 24. The air pipe is released from the air pipe reel 24 and connected to the air cylinder for driving the air cylinder to act with an external air source. As the support frame 21, the gripper 22, the driving device 23, etc. move up and down, the air tube reel 24 also rotates to retract and release the air tube to ensure the normal connection between the air tube and the air cylinder.

The grasping mechanism 20 further includes a limit switch (not shown) arranged on the supporting frame 21 and located on the side of the driving device 23, and a cable reel 25 with a cable wound on the supporting base 30. The cable reel 25 can rotate to take up and take up the cable; the cable is released from the cable reel 25 and connected to the limit switch. When the driving device 23 acts, the limit switch is triggered, and the limit switch transmits a signal to the control terminal through a cable to feedback the grasping and placing situation of the grasping mechanism 20.

The grasping mechanism 20 further includes an encoder assembly 26 arranged on the support base 30 for measuring the vertical position of the grasping mechanism 20 in the fuel cavity 100.

Further, in this embodiment, the grasping mechanism 20 further includes a pulley assembly 27 provided at the upper end of the support frame 21 for the wire rope winding connection of the lifting mechanism 40. The wire rope of the lifting mechanism 40 wraps around the pulley assembly 27 and is connected to drive the grasping mechanism 20 to move up and down. Depending on the number of steel ropes of the lifting mechanism 40 is one or two, the pulley assembly 27 includes one or two pulleys.

As shown in FIGS. 3-5, the lifting mechanism 40 may include a lifting drum 41 wound with a wire rope, a motor, and a reducer 42. The steel wire rope is released from the lifting drum 41, passes through the through hole on the support base 30 and enters the fuel cavity 100, and is connected to the grasping mechanism 20. The motor and the reducer 42 are connected to the lifting drum 41, which drives the lifting drum 41 to rotate to retract the steel wire rope, and drive the grasping mechanism 20 to move up and down.

The lifting mechanism 40 also includes a weighing mechanism 43 that monitors the weight of the grasping mechanism 20 to determine whether to grasp the fuel assembly; the weighing mechanism 43 and the lifting drum 41 are located on opposite sides of the fuel cavity 100 on the support 30 . After the wire rope penetrates the grasping mechanism 20 in the fuel cavity 100, the end extends out of the fuel cavity 100 and is connected to the weighing mechanism 43.

Specifically, in this embodiment, after the steel wire enters the fuel cavity 100 and passes under the pulley assembly of the grasping mechanism 20, it extends upwards from the fuel cavity 100 to be connected to the weighing mechanism 43. As the lifting drum 41 lowers the steel wire rope, the grasping mechanism 20 can move downward along the fuel cavity 100; when the lifting drum 41 winds up the steel wire rope, the grasping mechanism 20 is driven to move upward along the fuel cavity 100. The weighing mechanism 43 detects the weight of the grabbing mechanism 20 suspended by the wire rope, and determines whether to grab the fuel assembly according to the weight change.

As shown in FIG. 4, the weighing mechanism 43 includes a support beam 431 fixed on the support base 30, a connecting plate 432 vertically suspended on the support beam 431 relative to the support beam 431, and a weighing probe 433 arranged on the connecting plate 432. . The end of the wire rope protruding from the fuel cavity 100 is connected to the connecting plate 432.

To improve safety, the lifting mechanism 40 may further include a safety brake 44 connected to the lifting drum 41. When the built-in brake on the motor and reducer 42 fails, the safety brake 44 acts to lock the lifting drum 41 and stop the retracting and unwinding of the wire rope. According to requirements, the lifting mechanism 40 may further include an emergency hand wheel 45 connected to the motor and the reducer 42. In an emergency state, the fuel assembly lifting or lowering action is completed by manually operating the emergency handwheel 45.

The opening and closing mechanism 50 is mainly used for opening and closing the opening at the bottom of the shielding cylinder 10, and the setting method is not limited, for example, a sealing cover that can be opened and closed, a valve, and the like.

In this embodiment, as shown in FIGS. 1 and 2, the opening and closing mechanism 50 is a closed ball valve structure.

Specifically, the opening and closing mechanism 50 includes a valve body 51, a ball 52 rotatably disposed in the valve body 51, a valve rod 53 connecting the ball 52 through the valve body 51, and a driving motor 54 connected and driving the valve rod 53 to rotate.

The valve body 51 is provided with a valve body passage 510 passing through opposite ends of the valve body 51. The valve body passage 510 communicates with the opening and communicates with the fuel chamber 100 through the opening. The ball 52 is provided with a ball channel 520 that can communicate with the valve body channel 510. The ball 52 can be rotated relative to the valve body 51 between a first position and a second position under the driving of the driving motor 54 and the valve stem 53; the angle between the first position and the second position can be 90°.

When the ball 52 is in the first position, the ball passage 520 communicates with the valve body passage 510 in parallel (as shown in FIG. 2), thereby opening the opening of the shielding cylinder 10. At this time, the fuel assembly can pass in and out of the fuel container through the opening and closing mechanism 50. Cavity 100. When the sphere 52 is in the second position, the sphere passage 520 and the valve passage 510 are staggered (for example, relatively vertical), thereby closing the opening of the shield cylinder 10, that is, closing the bottom of the fuel cavity 100, so that the fuel assembly can be enclosed in the fuel.内内100。 In the cavity 100.

Further, the nuclear fuel assembly loading and unloading container of the present invention further includes a water inlet pipe 60 arranged in the fuel cavity 100. The water inlet end of the water inlet pipe 60 extends above the shielding cylinder 10 to externally connect the cooling water circulation system, which is used to deliver the cooling water to the fuel cavity 100 and immerse the fuel assembly to cool it, so as to prevent the fuel assembly from being warmed during loading, unloading and transportation. Rise too high. There may be one or more inlet pipes 60.

The nuclear fuel assembly loading and unloading container of the present invention also includes a water outlet pipe 70 arranged in the fuel containing cavity 100 for pumping out the cooling water in the fuel containing cavity 100. The water outlet end of the water outlet pipe 70 extends above the shielding cylinder 10 to externally connect the cooling water circulation system, and forms a cooling water circulation circuit with the cooling water circulation system and the water inlet pipe 60 to drive the cooling water to circulate between the fuel cavity 100 and the cooling water circulation system.

Preferably, the water inlet end of the water outlet pipe 70 is located at the lower end of the fuel cavity 100, and the water outlet end of the water inlet pipe 60 may be at the upper end or the middle of the fuel cavity 100.

Further, the nuclear fuel assembly loading and unloading container of the present invention further includes a surrounding wall 80 surrounding the outer periphery of the support base 30. The surrounding wall 80 encloses the lifting mechanism 40 and the like provided on the support base 30 on the inside thereof, and at the same time also plays a role of protecting personnel.

In order to facilitate the lifting and transportation, the nuclear fuel assembly loading and unloading container of the present invention further includes a lifting device 90 connected to the outer surface of the shielding cylinder 10. A lifting lug 17 is correspondingly provided on the outer surface of the shielding cylinder 10 for the connection of a sling.

In this embodiment, as shown in FIG. 1, the sling 90 is U-shaped as a whole, the two sides of the open end are connected to the lifting lugs 17, and the closed end is located above the surrounding wall 80.

The nuclear fuel assembly loading and unloading container of the present invention realizes the air transportation of the fuel assembly of the core and the fuel assembly of the spent fuel pool between different compartments. During the transfer process, the loading and unloading container has a protective effect on the fuel assembly, and has the functions of radiation shielding and waste heat export.

The nuclear fuel assembly loading and unloading container of the present invention realizes the loading and unloading of nuclear fuel assemblies. Referring to Figures 1-5, the nuclear fuel assembly loading and unloading method may include the following steps:

S1. Lift and position the nuclear fuel assembly loading and unloading container at the fuel assembly storage place or above the core.

This hoisting is mainly carried out by hoisting the hoisting tool 90 on the shielding cylinder 10 by a crane, and hoisting the entire loading and unloading container to a predetermined position and docking with related equipment.

S2. The opening and closing mechanism 50 of the nuclear fuel assembly loading and unloading container operates to open the opening of the shield cylinder 10.

Among them, the drive motor 54 of the opening and closing mechanism 50 starts to drive the valve stem 53 to rotate, which drives the ball 52 to rotate at an equal angle of 90°, so that the ball passage 520 in the ball 52 communicates with the valve body passage 510 in parallel, thereby opening the opening and connecting with the fuel. The cavity 100 is connected.

After the opening is opened, the fuel cavity 100 in the shielding cylinder 10 communicates with the outside through the opening and the opening and closing mechanism 50.

S3. The lifting mechanism 40 above the shielding cylinder 10 operates to drive the grabbing mechanism 20 in the fuel cavity 100 of the shielding cylinder 10 to descend onto the fuel assembly.

The actions of the lifting mechanism 40 are as follows: the motor and the reducer 42 start to drive the lifting drum 41 to rotate and lower the wire rope, the grabbing mechanism 20 moves down along the fuel cavity 100 under the action of gravity, passes through the opening and closing mechanism 50 and enters the core and Align the fuel assembly to be grasped.

S4. The grasping mechanism 20 grasps the fuel assembly, and the lifting mechanism 40 acts to drive the grasping mechanism 20 to rise to transport the grasped fuel assembly into the fuel cavity 100.

After aligning and contacting the fuel assembly, the lifting mechanism 40 stops lowering the wire rope, and the grabbing mechanism 20 acts to grab the fuel assembly. After grabbing the fuel assembly, the motor of the lifting mechanism 40 and the speed reducer 42 drive the lifting drum 41 to rotate the winding wire rope, drive the grabbing mechanism 20 and the fuel assembly it grabs to rise, pass through the opening and closing mechanism 50 and enter the fuel cavity 100 , The lifting mechanism 40 stops winding the wire rope until it is in place, so that the grabbing mechanism 20 and the fuel assembly are suspended inside the shielding cylinder 10. The shield cylinder 10 functions as a radiation shield for the fuel assembly.

S5. The opening and closing mechanism 50 closes the opening.

When the opening is closed, the drive motor 54 of the opening and closing mechanism 50 starts to drive the valve stem 53 to rotate, which drives the ball 52 to rotate at an equal angle of 90°, so that the ball passage 520 in the ball 52 and the valve passage 510 are staggered (preferably perpendicular). The opening of the shield cylinder 10 is closed by communicating with the outside.

Through the above steps, the operation of transferring the fuel assembly to the container (charging) is completed.

Further, the loading and unloading method further includes the following steps:

S6. Inject cooling water into the fuel cavity 100 to submerge the fuel assembly to prevent the waste heat of the fuel assembly from causing excessive temperature rise of the fuel assembly.

S7. The crane lifts the nuclear fuel assembly loading and unloading container with the fuel assembly to the designated location, and docks the nuclear fuel assembly loading and unloading container with the related equipment at the designated location.

Designated locations include fuel assembly receiving devices, spent fuel pools, etc. During the lifting process, the shielding cylinder 10 and the opening and closing mechanism 50 jointly shield the radiation radiation of the fuel assembly. The guide structure 16 in the shielding cylinder 10 can prevent the fuel assembly from shaking and colliding with the inner wall of the shielding cylinder 10.

S8. The opening and closing mechanism 50 operates to open the opening of the shielding cylinder 10 and discharge the cooling water.

For details of the operation of the opening and closing mechanism 50, refer to the above step S2. According to the designated location, the cooling water is discharged into the fuel assembly receiving device or the spent fuel pool.

S9. The lifting mechanism 40 acts to drive the grabbing mechanism 20 down, lowering the grabbed fuel assembly to a specified height, and the grabbing mechanism 20 releases the fuel assembly.

S10. The lifting mechanism 40 acts to drive the grabbing mechanism 20 to rise into the fuel chamber 100, and the opening and closing mechanism 50 closes the opening.

The above steps can complete the loading and unloading of a single fuel assembly, and the loading and unloading operations of the entire stack of fuel assemblies can be completed by repeating the above steps S1-S10.

In the above loading and unloading method, when the fuel assembly is removed from the core and transferred to the spent fuel pool, the unloading process of the fuel assembly is realized; when the fuel assembly is transferred from the fuel assembly storage place to the core, the fuel assembly is realized Loading process.

The above are only the embodiments of the present invention and do not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made by using the content of the description and drawings of the present invention, or directly or indirectly applied to other related technologies In the same way, all fields are included in the scope of patent protection of the present invention.

Claims (20)

1. A nuclear fuel assembly loading and unloading container, which is characterized in that it comprises a shielding cylinder with a fuel cavity for accommodating the fuel assembly and cooling water, a grabbing mechanism arranged in the fuel cavity for grabbing and releasing the fuel assembly, A support seat provided above the shielding cylinder, a lifting mechanism provided on the support seat, and an opening and closing mechanism provided at the bottom of the shielding cylinder;

   The lifting mechanism is connected to and drives the grasping mechanism to move up and down along the axial direction of the fuel cavity; the bottom of the shielding cylinder is provided with an opening communicating with the fuel cavity for fuel assembly to pass in and out; The opening and closing mechanism closes or opens the opening.
2. The nuclear fuel assembly loading and unloading container according to claim 1, wherein the lifting mechanism comprises a lifting drum wound with a steel wire rope, a motor, and a reducer;

   The support seat is provided with a through hole communicating with the fuel cavity; the steel wire rope on the lifting drum enters the fuel cavity through the through hole, and is connected to the grasping mechanism;

   The motor and the reducer are connected and drive the lifting drum to rotate to retract the steel wire rope, and drive the grabbing mechanism to move up and down.
3. The nuclear fuel assembly loading and unloading container according to claim 2, wherein the lifting mechanism further comprises a weighing mechanism that monitors the weight of the grasping mechanism to determine whether to grasp the fuel assembly; the weighing mechanism and The lifting drum is located on the opposite sides of the fuel cavity on the support seat;

   After the steel wire rope passes through the grabbing mechanism in the fuel cavity, its end extends out of the fuel cavity and is connected to the weighing mechanism.
4. The nuclear fuel assembly loading and unloading container according to claim 3, wherein the weighing mechanism comprises a support beam fixed on the support base, a connecting plate that is vertically suspended on the support beam relative to the support beam, A weighing probe arranged on the connecting plate;

   The end of the steel wire rope protruding from the fuel cavity is connected to the connecting plate.
5. The nuclear fuel assembly loading and unloading container according to claim 2, wherein the lifting mechanism further comprises a safety brake connected to the lifting drum; and/or, the lifting mechanism further comprises a safety brake connected to the motor and the reducer Emergency handwheel.
6. The nuclear fuel assembly loading and unloading container according to claim 2, wherein the grasping mechanism includes a support frame, a pulley assembly provided at the upper end of the support frame, and an openable and closeable grab and release fuel provided at the lower end of the support frame. The gripper of the assembly, which is arranged in the support frame and is connected to a driving device that drives the opening and closing of the gripper;

   The steel wire rope of the lifting mechanism wraps the pulley assembly and is connected to drive the grasping mechanism to move up and down.
7. The nuclear fuel assembly loading and unloading container according to claim 6, wherein the driving device is an air cylinder; the grasping mechanism further comprises a trachea reel with a trachea wound on the support seat, the trachea The reel can rotate to retract the air pipe;

   The air pipe is released from the air pipe reel and connected to the air cylinder, and an external air source drives the air cylinder to move.
8. The nuclear fuel assembly loading and unloading container according to claim 6, wherein the grasping mechanism further comprises a limit switch arranged on the supporting frame and located on one side of the driving device, and arranged on the supporting seat The cable reel with the cable wound;

   The cable reel can rotate to take up and take up the cable; the cable is released from the cable reel and connected to the limit switch.
9. The nuclear fuel assembly loading and unloading container according to claim 6, wherein the grasping mechanism further comprises a vertical direction of the grasping mechanism arranged on the support base for measuring the vertical direction of the grasping mechanism in the fuel cavity. Position encoder component.
10. The nuclear fuel assembly loading and unloading container according to claim 1, wherein the top of the shielding cylinder is provided with a first flange for connecting with the support seat; the bottom of the shielding cylinder is provided with a second flange. The flange is used to connect with the opening and closing mechanism.
11. The nuclear fuel assembly loading and unloading container according to claim 1, wherein the inner wall of the fuel containment chamber is provided with a guide structure extending along the axial direction of the fuel containment chamber and slidingly fitted with the grasping mechanism.
12. The nuclear fuel assembly loading and unloading container according to claim 1, wherein the shielding cylinder includes an inner cylinder, an outer cylinder sleeved outside the inner cylinder, and an inner cylinder and an outer cylinder. Between the shielding layer; the inner space of the inner cylinder forms the fuel cavity.
13. The nuclear fuel assembly loading and unloading container according to claim 1, wherein the opening and closing mechanism includes a valve body, a sphere rotatably arranged in the valve body, a valve stem that passes through the valve body and connects to the sphere, A drive motor connected to and driving the valve stem to rotate;

    The valve body is provided with a valve body passage that penetrates opposite ends of the valve body and communicates with the opening; the ball is provided with a sphere passage that can communicate with the valve body passage;

    When the sphere is in the first position, the sphere passage and the valve body passage are connected in parallel to open the opening of the shielding cylinder;

    When the sphere is in the second position, the sphere passage and the valve passage are staggered to close the opening of the shielding cylinder.
14. The nuclear fuel assembly loading and unloading container according to any one of claims 1-13, wherein the nuclear fuel assembly loading and unloading container further comprises an inlet that is arranged in the fuel cavity and delivers cooling water to the fuel cavity. Water pipe; the water inlet end of the water inlet pipe extends above the shielding cylinder to externally connect the cooling water circulation system.
15. The nuclear fuel assembly loading and unloading container according to claim 14, wherein the nuclear fuel assembly loading and unloading container further comprises a water outlet pipe which is arranged in the fuel cavity and draws out the cooling water in the fuel cavity; The water outlet end of the water outlet pipe extends above the shielding cylinder to connect with the cooling water circulation system, and forms a cooling water circulation circuit with the cooling water circulation system and the water inlet pipe.
16. The nuclear fuel assembly loading and unloading container according to any one of claims 1-13, wherein the nuclear fuel assembly loading and unloading container further comprises a wall surrounding the outer periphery of the support base.
17. The nuclear fuel assembly loading and unloading container according to any one of claims 1-13, wherein the nuclear fuel assembly loading and unloading container further comprises a spreader connected to the outer side of the shielding cylinder.
18. A method for loading and unloading nuclear fuel assemblies, which is characterized in that it comprises the following steps:

    S1. Lifting and positioning the nuclear fuel assembly loading and unloading container of any one of claims 1-17 at the fuel assembly storage place or above the core;

    S2. The opening and closing mechanism of the nuclear fuel assembly loading and unloading container operates to open the opening of the shielding cylinder;

    S3. The lifting mechanism above the shielding cylinder acts to drive the grabbing mechanism in the fuel cavity of the shielding cylinder to descend onto the fuel assembly;

    S4. The grabbing mechanism grabs the fuel assembly, and the lifting mechanism acts to drive the grabbing mechanism up to transport the grabbed fuel assembly into the fuel cavity;

    S5. The opening and closing mechanism closes the opening.
19. The loading and unloading method according to claim 18, further comprising the following steps:

    S6. Inject cooling water into the fuel cavity to submerge the fuel assembly.
20. The loading and unloading method according to claim 19, further comprising the following steps:

    S7. The crane lifts the nuclear fuel assembly loading and unloading container with the fuel assembly to the designated location;

    S8. The opening and closing mechanism acts to open the opening of the shielding cylinder and discharge the cooling water;

    S9. The lifting mechanism acts to drive the grabbing mechanism down, lowering the grabbed fuel assembly to a specified height, and the grabbing mechanism releases the fuel assembly;

    S10. The lifting mechanism acts to drive the grabbing mechanism to rise into the fuel cavity, and the opening and closing mechanism closes the opening.