JP5055330B2 - Seismic isolation structure of trolley or fuel changer and operation method thereof - Google Patents

Description

  The present invention relates to an improvement in the operation method of a lifting equipment and a carriage that moves on a traveling track and a transverse track, and more particularly to a fuel changer installed on an operating floor of a nuclear power plant and an operation method thereof.

  A conventional fuel changer will be described with reference to FIG. FIG. 1 is a diagram showing an overall configuration of a fuel changer according to the present invention.

  In a nuclear reactor installed at a nuclear power plant, the fuel assembly in the reactor pressure vessel 2 is loaded or replaced by using the fuel changer 1 at the periodic inspection that is performed before the reactor is started and during the shutdown of the reactor. It is carried out. In this work, the spent fuel assembly is taken out of the reactor pressure vessel 2 and moved to the fuel storage pool 3 side, or a new fuel assembly is loaded into the reactor pressure vessel 2. Together with the work, the fuel assemblies having a variation in burnup in the core are rearranged.

  The fuel changer 1 is installed so as to straddle the fuel storage pool 3, the reactor well pool 4, and the reactor pressure vessel 2, and can travel freely on a traveling rail 6 laid on the operating floor 5. A fuel assembly having a carriage 7 that can freely traverse on a carriage 7 and a transverse rail 8 installed on the traveling carriage 7 and disposed in the core of a reactor pressure vessel located below the reactor well pool 4 The body is held by the gripping mechanism 11 at the lower end of the fuel gripping device 10 that is suspended from the traversing carriage 9, and the fuel gripping device 10 is lifted up to run, traverse, and store the fuel storage pool 3. The fuel assembly is transferred into the rack and operates so as to be separated from the gripping mechanism 11. These series of operations are controlled by a fuel changer control device installed on the fuel changer 1 or in a remote control room.

  In order to prevent the traveling carriage 7 and the traversing carriage 9 from derailing from the rails or falling over when the earthquake occurs, the fuel changer 1 has a traveling rail 6 or a traversal as shown in FIGS. A fall prevention fitting 21 is attached from the traveling carriage 7 and the traversing carriage 9 so as to surround the rail 8. The fall prevention metal fitting 21 has a strength that can withstand a load generated at that time by bringing the surface of the fall prevention metal fitting 21 into contact with the rail when the side carriage 7 or the transverse carriage 9 is skid or lifted. Further, since the fall prevention metal fitting 21 is provided, the traveling carriage 7 and the traversing carriage 9 are not derailed or fallen. Further, in a lifting machine having a carriage structure composed of a similar traveling carriage and a traversing carriage, a structure in which an interference 22 is provided along a track such as a rail as shown in FIG. 3 in response to an earthquake, as shown in FIG. There is a structure in which the derailment prevention metal fitting 23 is provided on the traveling carriage 7 and the transverse carriage 9 as described above. These are used to prevent derailment against the side slip of the hoisting machine subjected to earthquake motion by contact between the traveling carriage 7 or the transverse carriage 9 and the obstacle 22 and contact between the traveling rail 6 or the transverse rail 8 and the derailment prevention metal fitting 23. For lifting of the lifting machine, derailment is prevented by setting the height of the interference 22 and the derailment prevention fitting 23 to be higher than the lifting amount of the lifting machine.

  As a technology related to the earthquake of the fuel changer, the braking of the carriage is released or activated by the signal of the earthquake detection device provided in the fuel changer described in JP-A-9-17884, and the fuel change due to the seismic force is performed. There are structures and operation methods that do not hinder the drive function and safety of the replacement machine. Further, in order to reduce the seismic input at the time of the earthquake of the fuel changer described in JP-A-10-15368, a vibration control device is provided on the fuel changer to avoid resonance between the fuel changer and the ground motion. There is a way to do it. In Japanese Patent Laid-Open No. 2002-82193, a drive device for a fuel changer is a linear motor, and when an earthquake is detected by a seismic wave detection device, a steady suction force is generated between the moving coil and the stationary coil of the linear motor. In addition, there is a method for preventing the danger of being moved or overturned by the vibration of an earthquake by fixing the traveling carriage and the traversing carriage.

JP-A-9-17884 Japanese Patent Laid-Open No. 10-15368 JP 2002-82193 A

  Regarding the earthquake resistance of the conventional fuel changer, a method of preventing derailment by giving the metal fittings and rails of the fuel changer a strength that is not damaged by an earthquake is common. Similarly, the members of the fuel changer main body need to be configured with members that are not damaged by the earthquake. In response to an increase in the design seismic intensity due to the review of ground motion at the nuclear power plant, the fuel changer increases these dimensions to increase the generated stress in order to ensure the strength of the fall-prevention brackets, rails, and fuel changer body members. It is necessary to take measures such as reducing the number, increasing the quantity and distributing the load, or changing the material used for these parts to one having high mechanical strength. However, in the case where the dimensions and quantity cannot be changed due to physical interference between parts and the functional restrictions of the refueling machine, or when the material with the maximum mechanical strength already available is used. It is difficult to improve the earthquake resistance.

  When implementing the above modifications to improve the seismic resistance of existing fuel changers, it is necessary to install and process the change members while the fuel changers are installed in the nuclear power plant. Therefore, it is necessary to refrain from complicated and large amount of work, and reduction of the work amount is one of the problems.

  In addition, the ground-level ground motion at which the fuel changer is installed becomes the input ground motion to the fuel changer, but this seismic motion is different for each nuclear power plant. Here, since the fuel changer has few changes in the shape and function of the reactor building, the shape of the fuel changer has not been changed significantly in order to avoid creating an unknown cause of failure due to the structural change. For this reason, there is a possibility of setting up a fuel changer in a nuclear power plant having an earthquake motion that has a large vibration component that resonates with the fuel changer, and it is necessary to consider the reduction of this earthquake motion.

  Furthermore, the conventional method for dealing with earthquakes of fuel changers starts an effective function by detecting earthquakes caused by earthquake detection devices attached to the fuel changers. The effective function is started based on the above, and safety against earthquakes is not secured in advance.

  The above problem can be achieved as follows.

  The fuel changer needs to have an earthquake prediction information receiving device that receives the earthquake prediction information and transmits the signal to the fuel changer control device.

  It has been found that the natural period of the fuel changer varies depending on the position on the traverse rail of the traverse carriage. This is because the natural period changes almost smoothly when the traversing carriage is moved from the center of the traversing rail to the end. Therefore, when the strength of the structure frame of the fuel changer is examined by numerical analysis, the fluctuation range of the natural period is confirmed in advance. Then, by comparing the vibration component corresponding to each frequency with the seismic motion of the target nuclear power plant, the natural period having the least influence of the seismic motion is confirmed, and the position of the traverse carriage is determined.

  As a method of actual operation based on the above, when the earthquake prediction information receiving device of the fuel changer receives the earthquake prediction information, the device sends a signal to the fuel changer control device and controls the fuel changer control. When the device receives it, it issues a command to stop the operation of the refueling machine so far and a command to move the traversing cart to the position where the influence of the most seismic motion is least. Thereby, before the main vibration of the earthquake arrives, the fuel changer is moved to a state having a low influence on the earthquake.

According to the present invention, a cart structure composed of a traveling cart and a traversing cart, such as a fuel changer, is input to the cart by setting the cart position where the influence of the earthquake is small before the earthquake motion arrives. Since the seismic motion can be reduced and the load applied to the structure at the time of the earthquake can be reduced, a cart with excellent earthquake resistance can be provided.

Overall view of the fuel changer. The block diagram of the fall prevention metal fitting of a prior art. The block diagram of the derailment prevention method of a prior art. The block diagram of the derailment prevention method of a prior art. The block diagram of the fuel change machine of Embodiment 1 of this invention. BRIEF DESCRIPTION OF THE DRAWINGS FIG. BRIEF DESCRIPTION OF THE DRAWINGS FIG. The block diagram of the fuel change machine of Embodiment 2 of this invention. The block diagram of the fuel change machine of Embodiment 3 of this invention.

  Embodiments of the present invention will be described below with reference to the drawings.

  The configuration and function of the first embodiment of the present invention will be described below with reference to FIG.

  The fuel changer of the present invention uses an alarm issued from a system that predicts an earthquake and generates an alarm, for example, an emergency earthquake warning issued by the Japan Meteorological Agency, and the receiving terminal 31 that receives the signal receives control of the fuel changer. The fuel changer control device 32 is connected to the device 32, and the fuel changer control device 32 controls the driving of the traveling carriage 33 of the fuel changer, the transverse drive of the transverse carriage 34, and the raising / lowering drive of the fuel gripper 35. It is connected to the.

When the receiving terminal 31 receives the issued emergency earthquake bulletin, the reception terminal 31 transmits the received information to the fuel changer control device 32, and the fuel changer control device 32 responds to the earthquake motion that arrives after the warning is issued. issues a drive command to the small transverse carriage positions 3 7 affect the structure of any current transverse carriage positions 3 6 moves the transverse carriage 34. Here, if the fuel changer is in automatic operation, the automatic operation is terminated, and if it is handling fuel, the fuel changer control device is set in the movement route at the time of earthquake set in advance in the fuel changer control device. A drive command is issued to drive the lift of the fuel gripper along with the traveling drive of the traveling carriage, and move to the specified coordinates to avoid interference with the reactor building wall surface due to the movement of the transverse carriage. Move the traversing cart. The order may be given by a person or automatically.

Here, the position of the traversing carriage that has little influence on the structure of the fuel changer with respect to the earthquake can be raised as follows: When carrying out, confirm the fluctuation range of the natural cycle, compare the vibration component corresponding to each cycle with the earthquake motion of the target nuclear power plant, and the traversing cart position corresponding to the natural cycle with the least influence of the earthquake motion.
(2) As shown in FIG. 6, when the ground motion is inputted to the fuel changer, the girder 38 of the traveling carriage vibrates and the traversing carriage 34 is affected by the vibration amplitude. Since the vibration amplitude is larger than the saddle 39, which is the fixed portion of the girder 38 having the smallest vibration amplitude.
(3) As shown in FIG. 7, for the purpose of preventing only the derailment of the traversing carriage 34, it is not a moving range during normal operation but a part in the traversing direction that does not hinder the work, for example, the end, and is firmly there An interference 40 for preventing derailment and the like is installed on the traveling carriage to be a retreat position at the time of the earthquake.

  In the first embodiment, when the seismic reinforcement is carried out on the existing equipment in the fuel changer, basically, only the installation of the receiving terminal and the control software of the fuel changer control device are modified, so that the modification work is easy. It is. Therefore, the introduction is possible with a short time and at a low cost.

  Embodiment 2 is shown below as a modification of the present invention. The configuration and function of the second embodiment will be described below with reference to FIG.

  Similarly to the first embodiment, the fuel changer according to the second embodiment uses the earthquake early warning, and the receiving terminal 31 that receives the signal is connected to the fuel changer control device 32, and the fuel changer control is performed. The device 32 is connected to these drive units in order to control the travel drive of the travel carriage 33 of the fuel changer, the traverse drive of the traverse carriage 34, and the lift drive of the fuel gripper 35. Further, the fuel changer has an additional moving carriage 50 different from the traversing carriage on the traveling carriage, and the fuel changer control device is also connected to the drive unit of the moving carriage 50. The second embodiment is added when the method of moving the traversing cart to the traversing cart position corresponding to the natural cycle having the least influence of the ground motion is used when a desired natural cycle cannot be changed only by moving the traversing cart. The moving cart is moved to increase the natural period variation. It can also be used when the natural period is changed without moving the traversing carriage. With this configuration, it is possible to cope with larger vibrations.

  Embodiment 3 is shown below as a modification of the present invention. The configuration and function of the third embodiment will be described below with reference to FIG.

  As in the first embodiment, the fuel changer according to the third embodiment uses the earthquake early warning, and the receiving terminal 31 that receives the signal is connected to the fuel changer control device 32, and the fuel changer control is performed. The device 32 is connected to these drive units in order to control the travel drive of the travel carriage 33 of the fuel changer, the traverse drive of the traverse carriage 34, and the lift drive of the fuel gripper 35. Further, the fuel changer normally keeps a load on the operating floor 60, and a moving carriage 61 that moves together with the traveling carriage 33, and a pulling drive device 62 that pulls the moving carriage 61 to the traveling carriage 33 during an earthquake. The fuel changer control device is also connected to the pulling drive device 62. FIG. 9 (A) shows the state of the mobile carriage during normal times, and FIG. 9 (B) shows the state of the mobile carriage during an earthquake. In the third embodiment, the fluctuation range of the natural period is small and it is difficult to obtain the natural period in which the effect is most effective. However, the load is moved to the fuel changer by slightly raising the movable carriage 61 from the operating floor 60. Since the natural period changes, the earthquake can be dealt with more quickly than in the first embodiment. For this reason, it is an effective means when the time from the earthquake prediction information to the arrival of the actual earthquake is short.

DESCRIPTION OF SYMBOLS 1 Fuel changer 2 Reactor pressure vessel 3 Fuel storage pool 4 Reactor well pool 5,60 Operating floor 6 Traveling rails 7,33 Traveling cart 8 Traverse rails 9,34 Traversing cart 10 Fuel gripping device 11 Grasp mechanism 21 Fall prevention Metal fittings 22 and 40 Interfering object 23 Derailment prevention metal fitting 31 Receiving terminal 32 Fuel changer control device 35 Fuel gripper 36 Current transverse carriage position 37 Traverse carriage position 38 having little influence on structure Girder 39 Saddle 50 and 61 Movement Carriage 62 Lifting drive

Claims (4)

A traveling carriage that moves on a traveling track, a traveling carriage that moves on a traveling track attached on the traveling carriage, a control device that controls the position of the traveling carriage and the transverse carriage, and the traveling carriage and the transverse carriage In the cart of the structure in which the traveling cart and the traversing cart are not derailed from the traveling track and the traversing track at the time of an earthquake by the derailment preventing means attached to
A cart having a device for receiving earthquake prediction information and transmitting the received information. A traveling carriage that moves on a traveling track, a traveling carriage that moves on a traveling track attached on the traveling carriage, a control device that controls the position of the traveling carriage and the transverse carriage, and the traveling carriage and the transverse carriage In a driving method in which a carriage having a structure in which the traveling carriage or the traversing carriage does not derail from the traveling trajectory or the traversing trajectory moves on the trajectory by the derailment prevention means attached to
The earthquake prediction information is received by the device that transmits the earthquake prediction information, and the received information is transmitted to the control device, and the control device issues a command to the traversing carriage after receiving the desired position. A driving method in which the carriage moves on the track, the seismic intensity applied to the carriage is reduced by changing the natural frequency of the carriage by moving the carriage. A traveling carriage that moves on a traveling track; a traversing carriage that moves on a traveling track attached on the traveling carriage; a mast that is installed on the traveling carriage and extends downward; A fuel gripper installed at the lower end of the mast, a control device for controlling the position of the traveling carriage, the traversing carriage and the mast depth, and a derailment prevention means attached to the traveling carriage and the transverse carriage In the fuel changer having a structure in which the traveling cart or the traversing cart does not derail from the traveling track or the traversing track at the time of an earthquake,
A fuel changer comprising a device for receiving earthquake prediction information and transmitting the reception. A traveling carriage that moves on a traveling track; a traversing carriage that moves on a traveling track attached on the traveling carriage; a mast that is installed on the traveling carriage and extends downward; A fuel gripper installed at the lower end of the mast, a control device for controlling the position of the traveling carriage, the traversing carriage and the mast depth, and a derailment prevention means attached to the traveling carriage and the transverse carriage In the operation method of the fuel changer having a structure in which the traveling cart or the traversing cart does not derail from the traveling track or the traversing track at the time of an earthquake,
The earthquake prediction information is received by the device that transmits the earthquake prediction information, and the received information is transmitted to the control device, and the control device issues a command to the traversing carriage after receiving the desired position. An operation method in which a carriage moves on a track, wherein the dampness applied to the fuel changer is reduced by changing the natural frequency of the fuel changer by moving the vehicle.

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