JPS6226720B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION This invention is applied to a pressure tube nuclear reactor to load fuel assemblies, seal plugs and seal plugs,
This invention relates to a fuel exchange machine that performs extraction.

Pressure tube nuclear reactors are well known, and include a large number of pressure tubes filled with primary cooling water, in which fuel assemblies, shield plugs, and seal plugs are loaded to form a reactor core. Then, for fuel exchange, connect the fuel exchanger to the lower end of the specified pressure pipe, and use a grab operation to remove the seal plug, seal plug, etc.
The spent fuel is extracted and stored in the exchanger, and then new fuel, etc., previously stored in the exchanger is inserted into the pressure pipe. In addition, spent fuel, etc. is transferred to the fuel exchange pool by the running of the fuel exchange machine, from here it is transferred into the pool through the transfer port, and then transported to the spent fuel handling facility via the fuel loading/unloading machine, transfer asyute, etc. Ru.

By the way, conventional fuel exchange machines for pressure tube nuclear reactors are configured so that the transfer of fuel between the reactor core and the fuel exchange machine and between the fuel exchange machine and the fuel exchange pool are all carried out through the upper port of the fuel exchange machine. ing. Therefore, in order to transfer spent fuel to a fuel storage pool, it is necessary to first lift it into another fuel exchange pool located above the fuel exchange machine and then lower it back into the fuel storage pool. A transfer port is used to maintain the water level in the fuel exchange pool.
This makes the operation of opening and closing the transfer shaft troublesome, which in turn hinders the efficiency of fuel exchange work.

As a solution to this problem, the fuel exchange pool is installed at the same height as the fuel exchange room, and instead, the transfer between the fuel exchange machine and the fuel exchange pool is carried out via an underground underwater transfer passage. A new fuel exchange method has already been proposed. Such a system is shown in FIG. In the figure, 1 is the reactor core, and 2 is its pressure tube. A fuel exchange chamber 3 is defined below the reactor core 1, and a fuel exchange pool 5 is defined in the fuel handling building 4 at the same level as the fuel exchange chamber 3, and a straddle is provided between the chamber 3 and the pool 5. An underground underwater transfer passageway 6 is constructed. A fuel exchange machine 8 that runs along a running rail 7 is installed in the fuel exchange room 3, a fuel inlet/out machine 9 is installed above the pool 5, and an underwater transfer machine 10 is installed in the underwater transfer passage 6. There is. Further, the fuel exchange chamber 3 and the underwater transfer passage 6 communicate with each other through a transfer port 12 equipped with a snout 11 with a valve on the upper part, and the communication between the fuel exchange pool 5 and the underwater transfer passage 6 is through a transfer port 13. There is a continuous connection.

The fuel exchanger 8 is a traveling trolley 1 that runs between the reactor core 1 and the transfer port 12 along the rails 7.
4. A pressure vessel 15 that accommodates the fuel loaded on the truck 14, a magazine that individually accommodates the fuel assemblies, seal plugs, and seal plugs housed in the pressure vessel 15, its drive mechanism, fuel, etc. pressure tube 2
It is equipped with a grab mechanism for inserting and withdrawing the device. Then, a snout 16 provided at the upper part of the pressure vessel 15 is connected to the pressure pipe 2 at the position shown by the chain line, and fuel, etc. is pulled out and inserted by a grab operation. Next, when the traveling trolley 14 is moved to the solid line position, the snout 12 is connected to the lower port 17 provided at the lower part of the pressure vessel 15, and in this state, the gripper 18 installed, for example, on the fuel exchange chamber side is passed through the upper port 19 to the pressure vessel 15. Suspended into 15,
Furthermore, the already contained spent fuel and the like are grabbed by the gripper 18 and transferred to the underwater transfer device 10 via the lower port 17 and the transfer port 12. The underwater transfer device 10 moves from left to right in the passage 6, and fuel is pulled up to the fuel exchange pool 5 by the fuel inlet/output device 9 through the transfer port 13.

The above fuel exchange method differs from the conventional fuel exchange method in that fuel is transferred from the upper and lower parts of the pressure vessel 15 of the fuel exchange machine 8 to the pressure pipe 2 of the reactor core 1 and between the underwater transfer machine 10, respectively. etc. need to be delivered. For this reason, if the conventional fuel exchanger is used as is, it is not possible to carry out the above-mentioned delivery of fuel, etc., and it is necessary to develop a new fuel exchanger in accordance with the new fuel exchange method.

The present invention has been made in view of the above points, and its object is to provide a novel fuel exchanger that is not conventional and is compatible with the above-mentioned new fuel exchange method.

The present invention will be described in detail below based on illustrated embodiments.

First, the overall structure of the fuel exchanger main body will be described with reference to FIG. A rotating drum type magazine assembly 20 is housed inside a pressure vessel 15 mounted on a traveling carriage (not shown). The assembly includes a disk 22 supported via bearings 21 at the top and bottom;
It also includes a plurality of magazine tubes 23 supported between upper and lower disks and arranged on the same circumference. In the illustrated example, the magazine tube 23 is the third
As shown in the figure, there are eight of them, for example, four of them are used for new fuel and spent fuel, two are used for seal plugs, and the rest are used for seal plugs.
Reference numeral 24 indicates a fuel assembly accommodated in the magazine tube 23. Note that the magazine assembly 20 is rotationally controlled to any rotational position by a drive mechanism (not shown). On the other hand, in the pressure vessel 15, an upper guide tube 25 with a snout 16 attached above the magazine assembly 20 is connected to the magazine tube 23.
The guide pipe 2 is fixedly installed through the pressure vessel at a predetermined position on the same half-way as the arrangement of
A grab mechanism 27 including a grab 26 is provided directly below the grip 5. In addition, at another position with a phase shift of, for example, 180 degrees from the above, a gripper guide tube 28 with an upper port 19 at the top and a lower port 17 at the lower end sandwiching the magazine assembly 20 is located above the magazine assembly 20. Lower guide pipes 29 serving as elevating and lowering guide passages for fuel, etc., are fixedly installed and penetrate through the pressure vessels 15, respectively. Furthermore, the lower end of each magazine tube 23 is equipped with an open/close type magazine stopper 30, the detailed structure of which will be described later, and two locations corresponding to the grab mechanism 27 and lower guide tube 29 are equipped with An opening/closing operation mechanism 31 that opens and closes the magazine stopper 30 based on the pressure vessel is provided on the pressure vessel side. This magazine stopper 30 supports the weight of the fuel assembly 24 etc. stored in the magazine tube 23 and holds it in the tube. Lift up the fuel assembly 24 inside,
When suspending the magazine, the magazine stopper 30 of the corresponding magazine tube is opened. Note that the gripper 18 shown in FIG. 1 may be installed at the top of the pressure vessel 15 if installation space permits.

The foregoing description will describe the procedure for the fuel exchange operation based on the configuration shown in FIG. 2. First, the snout 16 is connected to the pressure pipe 2 of the reactor, and by lifting and lowering the grab 26 and rotating the magazine assembly 20, the spent fuel, etc. is separated into the seal plug, seal plug, and fuel assembly in that order. The fuel is drawn into the magazine tube 23, and fresh fuel, etc. prepared in advance in another magazine tube is loaded into the pressure tube. During this work process, while the glove 26 passes through the magazine tube 23, the magazine stopper 30 is opened by the opening/closing operation mechanism 31 in response to a command. Next, move the fuel exchanger 8 and connect the snout 1 of the transfer port 12 to the lower port 17 at the delivery position to the underwater transfer passage 6.
1 is connected, the gripper 18 removes the spent fuel 2 stored in the magazine tube 23.
Grab 4. Here, the magazine stopper 30 of the magazine tube is opened, and the spent fuel is suspended and transferred to the underwater transfer machine 10 through the lower guide pipe 29 and the lower port 17 by operating the gripper.

As described in the above operation procedure, the magazine stopper 30 is opened only when performing a grab operation and a gripper operation through the magazine tube 23, and the magazine stopper 30 is opened only when performing a grab operation and a gripper operation through the magazine tube 23.
When housed inside, it is closed and supports the weight of the fuel, etc. Next, specific embodiments of the magazine stopper 30 and the magazine stopper opening/closing operation mechanism 31 will be described with reference to FIGS. 4 to 6. Magazine stopper 30 is magazine tube 2
Two left and right stopper pieces 3 are swingably supported via pins 33 on a support stand 32 attached to the lower end of 3.
4, and this stopper piece 34 is arranged so as to enter and exit the magazine tube 23 from the side. Further, the stopper piece 34 has a cam portion 35 formed at its rear end, and the actuator 3 faces the cam portion.
6 is installed. The actuator 36 has a shaft 37 extending vertically, and a compression spring 38
The stopper piece 34 is urged to operate toward the closed position shown by the solid line. Note that 39 is a positioning stopper installed behind and facing the actuator 36. On the other hand, the magazine stopper opening/closing operation mechanism 31 includes a U-shaped bracket 41 slidably supported on a rail 40 provided on a support stand on the pressure vessel side, and an operation shaft 42 attached to the bracket 41.
The bracket 41 is formed with a circumferential groove 44 along the movement trajectory T of the actuator shaft 37 as the magazine assembly 20 rotates.

With the above structure, when the magazine assembly 20 rotates and reaches a predetermined fuel handling position, the actuator shaft 37 of the magazine stopper 30 fits into the circumferential groove 44 of the bracket 41 of the opening/closing operation mechanism 31. At this point, the magazine assembly 20 is stopped;
Next, a command is given to the hydraulic cylinder 43 to push the bracket 41 to the right. Therefore, bracket 41
The actuator 36 that is engaged moves to the right against the spring 38 and pushes the stopper piece 34 open toward the chain line position. When the grab operation or gripper operation is completed, the bracket 41 is returned to its original position, and the magazine stopper 30 returns to its closed state.

With the configuration of the magazine stopper 30 and the opening/closing operation mechanism 31, it is possible to prevent the fuel, etc. stored in the magazine tube 23 from falling out unexpectedly, and the opening/closing operation mechanism 31 is slightly moved from the position where the fuel, etc. is handled by the grab 26 and the gripper 18. They only need to be provided at two corresponding locations, and have the advantage that the overall structure can be constructed simply.

As described above, according to the fuel exchange machine of the present invention, it is possible to extract and insert fuel, etc. to and from the nuclear reactor located above, and to transfer fuel, etc. to and from the underwater transfer machine located below. This can be carried out smoothly without any problems, thus making it possible to realize the new fuel exchange method described in FIG. 1, as well as to rationalize the fuel exchange equipment and shorten the fuel exchange time based on the fuel exchange method.

[Brief explanation of the drawing]

Fig. 1 is an overall configuration layout diagram of a fuel exchange facility that employs the fuel exchange machine of the present invention, Fig. 2 is a cross-sectional view of the main parts of an embodiment of the present invention, and Fig. 3 is a cross-sectional view taken in the direction of the arrow in Fig. 2. 4 are enlarged views showing the detailed structure of the magazine stopper portion in FIG. 2, and FIGS. 5 and 6 are cross-sectional plan views of the main components in FIG. 4, respectively. 1: Reactor core, 2: Pressure pipe, 8: Fuel exchange machine, 14: Traveling truck, 15: Pressure vessel, 16: Snout, 17: Lower port, 18: Gripper, 2
0: Magazine assembly, 23: Magazine tube,
24: fuel assembly, 25, 29: elevating guide pipe for fuel, etc., 27: grab mechanism, 28: gripper guide pipe, 30: magazine stopper, 31: magazine stopper opening/closing mechanism, 36: actuator.

Claims (1)

[Scope of Claims] 1. A pressure tube nuclear reactor having a traveling truck running below the core, a pressure vessel mounted on the traveling truck, and a plurality of magazine tubes arranged on the same circumference, and inside the pressure vessel. A rotating drum-type magazine assembly rotatably supported, a fuel etc. lifting guide pipe with a snout installed at the top of the pressure vessel in alignment with the magazine tube, and a fuel etc. lifting guide pipe with a snout placed directly below the guide pipe with the magazine assembly in between. A grab mechanism is installed, a gripper guide tube is installed above the magazine assembly at a different position from the guide tube, and a fuel elevating guide tube with a lower port is provided below, installed at the lower end of each magazine tube. This is a fuel exchanger for a pressure tube nuclear reactor, consisting of an opening/closing magazine stopper for supporting fuel, etc., and a mechanism for opening/closing the magazine stopper. 2. In the fuel exchanger according to claim 1, the magazine stopper opening/closing operation mechanism is configured to engage with the actuator of the magazine stopper to open/close the stopper, and the grab mechanism and the lower part A fuel exchanger for a pressure tube type nuclear reactor, characterized in that it is arranged on a fixed side of a pressure tube in a position corresponding to each of the ported lifting guide tubes.