JPH0337158B2 - - Google Patents

Description

[Detailed description of the invention] [Technical field to which the invention pertains]

This invention relates to a fuel exchange machine for loading and unloading core components such as fuel, seal plugs, and shielding plugs for pressure tube nuclear reactors, and in particular, a magazine stopper opening/closing mechanism for a fuel magazine tube installed in the fuel exchange machine. Regarding the configuration of

[Prior art and its problems]

As a fuel exchanger for the pressure tube reactor mentioned above, a rotating drum type magazine assembly consisting of a plurality of magazine tubes with a magazine stopper mechanism is housed in the pressure vessel of the fuel exchanger that runs below the reactor core. , and among the fuel guide pipes installed above and below the magazine assembly, loading and unloading of fuel, etc. is carried out through the upper guide pipe through the pipe between the reactor pressure pipe and the magazine tube by a grab operation inside the aircraft. There is a known fuel exchange machine configured to perform the above operations and to transfer fuel, etc., to and from an external fuel transfer facility through a lower guide pipe (Japanese Patent Application Laid-Open No. 197893). The fuel exchanger is provided with a sliding horizontal shutter plate as its magazine stopper mechanism, and this shutter plate is opened and closed by a cam mechanism installed on the movable guide tube on the lower guide tube side, thereby simplifying the structure. A similar application has already been filed by the same applicant. (Patent application No. 59-263442
-140894) Next, the configuration of the above fuel exchanger is shown in Figures 3 to 6.
This will be explained with reference to the diagram. First, in FIGS. 3 and 4, reference numeral 1 indicates a pressure vessel of a fuel exchanger mounted on a traveling truck (not shown). A rotating drum type magazine assembly 3 equipped with a plurality of magazine tubes 2 is housed. on the other hand,
An upper guide tube 4 with a snout and a gripper guide tube 5 with a port valve are disposed above the magazine assembly 3 in the center, and a fixed guide tube 6 is disposed below the magazine assembly 3. A lower guide tube combined with a movable guide tube 7 and a grab guide tube 9 housing a grab mechanism 8 are each pulled out from the pressure vessel 1 and installed. Each magazine tube 2 constituting the magazine assembly 3 is equipped with an opening/closing type magazine stopper mechanism 10 at its lower end, the detailed structure of which will be described later. A cam mechanism 11 for opening/closing the magazine stopper mechanism is mounted on the upper end of the movable guide tube 7 on the opposite side. Further, a cylinder for driving up and down, indicated by reference numeral 12, is connected to the movable guide tube. The above-mentioned magazine stopper mechanism 10 supports the weight of the fuel 13 etc. stored in the magazine tube 2 and holds it in the magazine tube, and when the fuel 13 is carried in and out through the lower guide pipe by operating the gripper. In this case, the stopper mechanism 10 of the magazine tube communicating with the lower guide pipe 6 is opened to allow fuel to pass through. Here, to explain the procedure for exchanging fuel with the above configuration, first connect the snout to the pressure pipe of the reactor, and by lifting and lowering the grab 8 and rotating the magazine assembly 3, the used fuel is pulled out from the pressure pipe side. Core components such as fuel are drawn into the magazine tube 2, and new fuel previously stored and held in another magazine tube is loaded into the pressure tube instead. In addition, in this state, the magazine stopper mechanism 1
0 is closed, and in this state, only the grab 8 freely passes through the remaining passage inside the stopper mechanism and is operated up and down. When the fuel exchange work with the reactor is completed in this way, the fuel exchange machine moves to another fuel delivery position, and at this position connects the port of the lower guide pipe to the transfer port on the fuel transfer equipment side. In this state, a gripper of a fuel handling device (not shown) is suspended through the upper guide pipe 5 to grasp the spent fuel 13 housed in the magazine tube. Subsequently, the magazine stopper mechanism 10 provided in the magazine tube is opened, and the gripper is operated to lower the spent fuel to the transport equipment side through the lower guide pipes 6 and 7 and carry it out. Conversely, when carrying in fuel, the new fuel is drawn into the magazine tube in the reverse order to the above. As mentioned in the above procedure, the magazine stopper mechanism is opened only when carrying out or carrying in fuel through the lower guide tube, and is closed when other fuel is stored in the magazine tube.
Fuel is held within the magazine tube. Next, the structure and operation of the magazine stopper mechanism and its opening/closing operation mechanism in the previously applied fuel exchanger will be explained with reference to FIGS. 5 and 6. 5 and 6, the magazine stopper mechanism 10 includes a housing 14 attached to the lower end of the magazine tube 2, and a housing 14 attached to the lower end of the magazine tube 2.
A sliding horizontal shutter plate 15 is sandwiched between the upper and lower guide plates 14a and 14b and arranged on both the left and right sides, and a biasing spring that biases the shutter plate 15 from behind to protrude into the fuel passage. 16, and the shutter plate 15 has a guide pin 17 projecting laterally from both sides thereof, which passes through a horizontal long groove 10a cut out in the side surface of the housing 14, and extends in the horizontal direction of arrow A. Supported in a slidable manner. On the other hand, the movable guide tube 7 is located opposite the magazine stopper mechanism 10.
The cam mechanism 11 for opening/closing the stopper mechanism mounted on the upper end has a guide cam groove bent at a midway point, as shown by reference numeral 18, formed on the inner wall surface of the cam mechanism 11 facing the guide pin 17. It becomes something. Here, the guide cam groove 18 is bent such that its upper end opens opposite to the guide pin 17 of the shutter plate in the illustrated closed position, and recedes outward from there. Next, the operation of the above configuration will be explained. First, as shown in the figure, when the movable guide tube 7 is in the lowered position, the magazine stopper mechanism 10 and the cam mechanism 11 are separated from each other, and the magazine assembly is
The shutter plate 15 is not restricted by the cam mechanism 11 and can rotate freely without interference with the spring 1.
6, it protrudes into the fuel passage and holds the stopper mechanism in the closed position. From this state, when the movable guide tube 7 is raised in the direction of arrow B by driving the cylinder 12 shown in FIG. The guide pin 17 on the shutter plate side comes to fit into the guide cam groove 18. Then, as the movable guide tube rises further,
The cam mechanism 11 moves to the position indicated by the chain line in FIG.
The stopper mechanism is opened by moving the stopper mechanism backward from the fuel passage. In this state, fuel can freely pass between the magazine tube 2 and the lower guide tube 7. Furthermore, when the movable guide tube 7 is lowered again after the fuel carrying-out and carrying-in operations are completed, the shutter plate 15 is guided in the opposite direction to close along the guide cam groove 18 of the cam mechanism 11, and the magazine stopper mechanism 10 and cam mechanism 1
1 is released, the magazine stopper mechanism is held in the closed position by the biasing force of the biasing spring 16, thereby completing a series of opening and closing operations of the magazine stopper mechanism. The opening/closing stroke of the shutter plate 15 in the above operation is represented by S in FIG. However, it has been found that the magazine stopper mechanism equipped with the sliding shutter plate described above has the following problems. That is, the inner diameter of the magazine tube 2 is set to match the fuel and the shielding plug, which are core components housed here, and which have a large diameter, and are larger than the diameter of the fuel. For this reason, when the magazine stopper mechanism is in the closed state, when the fuel is suspended in the magazine tube 2, if the fuel storage position is biased toward the magazine tube and eccentric, the fuel 13 will be stored as shown by the chain line in FIG. The posture is tilted, and as a result, the lower edge of the fuel 13 comes off the shutter plate 15 and a part of it falls between the shutter plates 15. On the other hand, in this supported state, the shutter plate 15 receives a force in the direction of arrow F due to the weight G of the fuel, and the shutter plate 15 is pushed back in the opening direction against the biasing spring 16. As a result, there is a risk that a serious accident may occur in which the fuel unexpectedly falls out of the magazine tube 2. Further, in order to stroke the shutter plate 15 in the horizontal direction, a large space is required to accommodate the shutter plate in the retracted position, and the housing 14 becomes larger accordingly. Furthermore, when the shutter plate is opened and closed, galling occurs between the upper and lower guide plates 14a, 14b and the shutter plate, making the opening and closing operation unstable.

[Purpose of the invention]

The present invention has been made in consideration of the above points, and an object of the present invention is to provide a highly reliable fuel exchanger that eliminates the drawbacks of the conventional configuration described above and enables reliable opening and closing operations of the magazine stopper mechanism. do.

[Key points of the invention]

In order to achieve the above object, the present invention uses a swing-type shutter plate that tilts around a support shaft as a shutter plate in a magazine stopper mechanism, and tilts the shutter plate through a cam mechanism by raising and lowering a movable guide tube. This prevents the shutter plate from galling, which was a problem with conventional sliding shutter plates, and from accidentally opening the shutter plate due to the eccentric load of the fuel stored in the magazine tube. This is how it was done.

[Embodiments of the invention]

1 and 2 show the main structure of a fuel exchanger according to an embodiment of the present invention, and the same members corresponding to those in FIG. 5 are given the same reference numerals.
Here, the configuration of the entire fuel exchanger is the same as that shown in FIG. 5, and its explanation will be omitted. That is, according to the present invention, the magazine stopper mechanism 10 includes a housing 14 attached to the lower end of the magazine tube 2, two swing-type shutter plates 19 disposed on both sides inside the housing, and a magazine stopper mechanism 10 that constantly controls the shutter plates 19. It is an assembly with a tension spring 20 that urges it toward the closed position so as to protrude into the fuel passage. Here, the shutter plate 19 has a rotary shaft 21 attached to one end thereof, which is pivotally supported by a bearing bush 22 fixed to the housing 14 side, and a guide pin 23 protruding from both left and right sides of the shutter plate 19 is attached to the side surface of the housing 14. It penetrates through the long groove 24 and protrudes. Note that 25 is a stopper member for regulating the closed position of the shutter plate 19. On the other hand, the magazine stopper mechanism 1
A guide cam groove 18 is formed in the cam mechanism 11 on the side of the movable guide tube 7 opposite to the movable guide tube 7. The guide cam groove 18 fits into the guide pin 23 described above. Next, the operation of the above configuration will be explained. First, when the movable guide tube 7 is in the lowered position as shown in the figure, the magazine stopper mechanism 10 and the cam mechanism 11 are separated from each other, and the shutter plate 19 of the magazine stopper mechanism 10 is biased by the tension spring 20. The magazine tube 2 is held in a closed position in response to this, and in this state, core components such as fuel contained in the magazine tube 2 are held within the tube. On the other hand, when the movable guide tube 7 is lifted from this state, the cam mechanism 11 rises together with the movable guide tube 7 and is coupled to the magazine stopper mechanism 10, and the guide cam groove 18 is inserted into the guide cam mechanism 11 on the shutter plate 19 side. Pin 23 is inserted. From here, if you move up the movable guide tube further, you will see guide pin 2.
3 is restrained and guided along the guide cam groove 18,
The shutter plate 19 has a tension spring 2 centered around the rotating shaft 21.
It tilts as shown by arrow C toward the open position shown by the chain line against the spring force of 0, and retreats from the inside of the fuel passage. In this state, fuel can freely pass between the magazine tube 2 and the lower guide tube. In addition, if the movable guide tube 7 is lowered again after the fuel transfer operation between the magazine tube 2 and the fuel transfer equipment outside the machine is completed, the shutter plate 1
9 is guided in the closing direction, and when the coupling between the magazine stopper mechanism 10 and the cam mechanism 11 is released, the shutter plate 19 is again biased by the spring and held in the closed position. In this case, with the shutter plate 19 of the magazine stopper mechanism 10 closed, the magazine tube 7
Even if the fuel stored in the magazine tube is tilted to one side in the magazine tube as shown in FIG. Since the rotating shaft 21 is rotatably supported, there is no fear that the shutter plate will open unexpectedly due to the weight of the fuel acting from above.
This makes it possible to reliably prevent fuel from falling out, which has been a problem with conventional sliding shutter plate structures. Furthermore, the swing type shutter plate does not cause galling unlike the slide type structure when opening and closing the shutter plate, and since the shutter plate is housed in the housing 14 in a vertical position in the open position, it is possible to move the shutter plate away from the magazine tube 2. There are also advantages such as the ability to reduce the size of the housing 14 that protrudes toward the side, thereby making the housing more compact in terms of space.

【Effect of the invention】

As described above, according to the present invention, the shutter plate installed in the magazine stopper mechanism is a swing type shutter plate, and the shutter plate is tilted and opened/closed via the cam mechanism by raising and lowering the movable guide tube. This structure eliminates all the problems of the conventional sliding shutter plate structure, such as the accidental falling of the stored fuel, the galling of the shutter plate, and the large housing space required to open and close the shutter plate. Accordingly, it is possible to provide a fuel exchanger that has reliable opening/closing operations and is highly reliable in storing and holding fuel.

[Brief explanation of the drawing]

Fig. 1 is a partially cutaway side view showing the main structure of a fuel exchange machine according to an embodiment of the present invention, Fig. 2 is a cross-sectional view taken in the direction of the arrow in Fig. 1, and Fig. 3 is a cross-sectional view of the overall structure of the fuel exchange machine. , FIG. 4 is a sectional view taken along the arrow in FIG. 3, FIG. 5 is a conventional structural diagram corresponding to FIG. 1, FIG. 6 is a sectional view taken along the arrow in FIG.
It is a state explanatory diagram when the stored fuel is eccentric in the figure. 2: Magazine tube, 3: Magazine assembly,
6: Lower guide tube, 7: Movable guide tube, 10: Magazine stopper mechanism, 11: Cam mechanism, 12: Drive cylinder of movable guide tube, 13: Fuel, 18: Guide cam groove of cam mechanism, 19: Swing type Shutter plate, 20: biasing spring of the shutter plate, 21: rotating shaft of the shutter plate, 23: guide pin of the shutter plate.

Claims (1)

[Scope of Claims] 1. A rotary drum type magazine assembly consisting of a plurality of fuel storage magazine tubes equipped with a magazine stopper mechanism at the lower end, with piping arranged above and below the magazine assembly, sandwiching the magazine assembly. In a fuel exchange machine that exchanges fuel with the reactor and transfers fuel to and from the fuel transfer equipment outside the aircraft through each fuel guide pipe, the magazine is equipped with a swing type shutter plate that is always biased in the closing direction. a stopper mechanism, a movable guide tube that is movable up and down and forming a part of the lower guide tube, and a cam mechanism for opening and closing the shutter plate mounted on the upper end of the movable guide tube facing the magazine stopper mechanism; A pressure tube characterized in that the pressure tube is equipped with means for driving a movable guide tube up and down, and is configured to open and close by tilting a shutter plate of a magazine stopper mechanism via a cam mechanism by lifting and lowering the movable guide tube. Refueling machine for nuclear reactor. 2. In the fuel exchange machine according to claim 1, the shutter plate installed in the magazine stopper mechanism is a swing type shutter plate with one end pivotally supported in the housing, and the shutter plate facing the magazine stopper mechanism The cam mechanism for opening and closing the plate is formed with a guide cam groove that engages with a guide pin protruding laterally from the shutter plate and tilts the shutter plate to the open position when the movable guide tube is raised. A fuel exchange machine for a pressure tube nuclear reactor characterized by the following.