JPS59107296A - Fuel exchanging facility of pressure tube type reactor - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to fuel exchange equipment for pressure tube nuclear reactors, and in particular to improvement of earthquake resistance of reactor buildings, rationalization of space for fuel exchange, and fuel exchange equipment. This invention relates to fuel exchange equipment that is simpler and easier to handle.

[Prior art]

FIG. 1 shows a conventional example of a space dedicated to a fuel exchanger and fuel transfer in the building structure of a pressure tube nuclear reactor. In this figure, 1 is a nuclear reactor, 2 is its pressure pipe, 3 is a reactor containment vessel, 4 is a foundation mat, 5 is an underground waterway provided in the foundation mat 4, 6 is a spent fuel storage pool, and 7 is their A refueling machine supported by a transverse truck 9 that moves horizontally at right angles on a traveling truck 8 that moves horizontally left and right in the drawing on a track laid below the reactor 1. 10//i Snout 11 coupled to pressure pipe 2
, a grab (not shown) that raises and lowers the fuel rod (not shown)
, a magazine (not shown) that accommodates the fuel rods, a fuel shielding plug attaching/detaching device (not shown) that connects or separates the fuel rods and the lower shielding plug (not shown), water supply to the fuel exchanger 10, and a used fuel rod. Feed water cooling system that removes the decay heat of fuel (
(not shown).

When performing fuel exchange, new fuel rods and new seal plugs are stored in the magazine in the fuel exchanger 10, moved to the lower part of the designated pressure pipe 2 by the trolley 8.9, and after positioning, the snout 11 is It is connected to the pressure pipe 2. Next, the spent seal plugs, spent fuel rods, and lower shielding plugs inserted into the pressure pipe 2 are pulled out by a grab, and the new fuel rods and new seal plugs housed in the magazine in the fuel exchanger 10 are removed. and exchange each. Thereafter, the snout 11 is moved through the pressure pipe 2, and the refueling machine 10 is moved to the upper part of the access boat 12 using the platform 8.9. Next, after connecting the lower part of the fuel exchanger 10 and the inlet/outlet boat 12, the upper fuel rod inlet/outlet gripper 13 grips the spent fuel rods and seal plugs in the magazine of the fuel exchanger 10, and then removes the spent fuel rods and seal plugs from the inlet/outlet port 12.
After that, the underwater transfer cart 14 is transferred to the water 7 in the underground waterway 5 provided in the foundation mat 4.
The spent fuel rods and seal plugs in the underwater transfer vehicle 14 are transferred to the water 7 of the spent fuel storage pool 6 via the delivery boat 15. However, the above conventional technology has the following drawbacks.

(1) Providing an underground waterway 5 in the foundation mat 4 is not at all preferable in terms of structure, strength, and construction work.

(2) Since the fuel exchanger 10 incorporates the various devices described above, its height needs to be 3.5 times the length of the fuel rods it handles, and this, combined with the presence of the access boat 12, So,
Since the height H in Figure 1 cannot be reduced, the earthquake resistance of the building is poor and it is difficult to make the building compact.

(3) As the above-mentioned steps for transferring fuel rods from one device to another must be performed in multiple stages, it is not only difficult to shorten the fuel exchange time, but also accidents that occur when fuel rods fall during the exchange work. As the number of opportunities for fuel exchange increases, a large number of equipment are required for each step, making the entire fuel exchange facility complex.

[Purpose of the invention]

In view of the above-mentioned drawbacks of the conventional technology, the present invention aims to improve the earthquake resistance and make the building more compact by making the foundation mat rational in terms of structure, strength, and construction, and by reducing the height occupied by the fuel exchange equipment inside the building. Another object of the present invention is to provide fuel exchange equipment for a pressure tube nuclear reactor that can shorten the time required for fuel exchange, simplify the work, and simplify the fuel exchange equipment.

[Summary of the invention]

The fuel exchange equipment for a pressure tube type nuclear reactor according to the present invention has a first movable system having a degree of freedom of movement in two horizontal directions so that it can be located directly under any pressure pipe of the reactor installed in the reactor building. a second movable conveyance device which is movable in at least horizontal left and right directions and is provided at a lower height than the first movable conveyance device; a lower end of any of the pressure pipes supported by the first movable conveyance device; a fuel rod handling device for moving fuel rods in and out of a pressure pipe that can be detachably connected to the fuel rod; A handling device, a fuel rod storage box for receiving and receiving fuel rods, and a second mobile transportation device that moves horizontally and the fuel rod storage box supported by the reactor lower area and the spent fuel. It is characterized by comprising a transport port that communicates with the storage pool.

[Embodiments of the invention]

One embodiment of the invention is generally shown in FIG.

In this figure, parts corresponding to those in FIG. 1 are designated by the same reference numerals.

In FIG. 2, a fuel tank is mounted on a traveling truck 8 that moves in the horizontal left and right directions in the figure on a track provided below the pressure tube reactor 1, and is supported by a transverse truck 9 that moves in the horizontal direction at right angles. The return handling machine 16 has a snout 11 that connects with the reactor G pressure pipe 2. Further, a fuel rod storage box 19 is supported by a traversing truck 18 that moves in a perpendicular horizontal direction while riding on a traveling truck 17 that moves in horizontal left and right directions in the figure on another track laid below the above-mentioned track. The upper part of the fuel rod storage box 19 is detachable from the lower part of the fuel rod handling machine 16.

FIG. 3 is a vertical sectional view showing the outline of the structure of the fuel rod handling machine 16 and the fuel rod storage box 19, and shows a state in which the two are connected. The fuel rod handling machine 16 is equipped with a snout 11 that can be connected to the pressure pipe 2 at the upper part, and inside is a chain 21 that moves the fuel rods 20 up and down, and a chain 21 that connects the fuel rods and a lower shielding plug (not shown). or a separating fuel shielding plug attaching/detaching device (not shown), a case 22 for storing the separated lower shielding plug, and a rod 23 for moving fuel rods in and out of the reactor.
It is equipped with The rod 23 is loosely fitted into a hole in an arm plate 26 fixed to a shaft 25 that can be rotated by a motor 24.
The lower end rests on a pedestal 27 fixed to the shaft 25.

The fuel rod handling machine 19 is equipped with a snout 29 that can be connected to the lower pipe 28 of the fuel rod handling machine 16, and is equipped with a chain 30 for raising and lowering the fuel rods 20 inside.

FIG. 4 is a sectional view showing an example of the structure of a connecting portion (section A in FIG. 3) that removably connects the pressure pipe 2 and the snout 11, and the lower tube 28 and the snout 29, respectively. In the same figure, 33 is a connecting pipe provided at the upper end of the snout 11 (29), which extends by the hydraulic cylinder 32 and can be fitted and connected to the pressure pipe 2 (or lower pipe 28), and 31 is the connecting pipe. This is a tension spring for withdrawal.

FIG. 5 is a cross-sectional view taken along line BB in FIG. In the figure, 34 is a motor for driving the chain 21, and the fuel rod 20
The movement into and out of the pressure pipe takes place by cooperating with said rod 23. That is, the chain 21 is provided with a plurality of protrusions 21'ζ21"..., and the protrusions 21' correspond to the actual rod 23', the fuel rod protrusion 20',
20'' and performs the operation of inserting and removing the fuel rods into and out of the pressure pipe 2.

The fuel rod handling machine 16 and the fuel rod storage box 19 are equipped with a water supply cooling system (not shown) for supplying water thereto and removing decay heat from the spent fuel.

In the above configuration, a process for performing fuel exchange will be described below with reference to FIGS. 6 to 10.

When the fuel rod handling machine 16 and the fuel storage box 19 are both horizontally moving and can be moved, they are connected to the lower pipe 28 and the snout 29, and then moved to the bogies 8.9 and 17.18. After moving to the lower part of the pressure pipe 2 and positioning it, the snout 11 is connected to the pressure pipe 2. Next motor 2
4, rotate the shaft 25 to move the rod 23 from the position shown in FIG.
When driven clockwise, its protrusion 21' engages with the lower side of the protrusion 23' of the rod 23 as shown in FIG.
is inserted into the pressure pipe 2, and then when the chain 21 is driven counterclockwise, the spent fuel rod 2o in the pressure pipe 2 is pulled down together with the rod 23, and the second protrusion 2 of the chain 21 is pulled down. It engages with and supports the lower side of the protrusion 20' (FIG. 7) of the fuel rod 20. At this point, install the fuel shielding plug attachment/detachment device (
A lower shielding plug (not shown) is separated from the spent fuel rod 20 (not shown) and is housed in the case 22. Next, when the chain is further driven counterclockwise, the spent fuel rod 2o and the rod 23 from which the lower shielding plug has been separated are moved further downward, and as shown in FIG. ' and 23' become unconsolidated. In this state, the motor 24 rotates the shaft 25 by 180 degrees to rotationally move the rod 23 to the position shown in FIG. During this time, the spent fuel rod 20 is immovably supported by the protrusion 21''.Then, from the state shown in FIG.
When the fuel rod 1 is driven counterclockwise, the fuel rod 2° is further lowered, and the protrusion 20' is separated from the protrusion 21'' while the protrusion 20'' is supported by the protrusion 21' of the chain 21. The fuel rod 20 is connected to the lower pipe 28 and the snout 2 as shown in FIG.
9 into the fuel storage box 19, and its protrusion 20' is supported by the protrusion 30' of the chain 30. Then, by driving the chain 21.30 counterclockwise,
After the protrusion 20'' is removed from the protrusion 21', the spent fuel rod 20 is finally completely stored in the fuel storage box 19 as shown in FIG.

After the spent fuel rods 20 are stored in the fuel rod storage box 19,
The snout 29 of the fuel rod storage box 19 is separated from the lower pipe 28 of the fuel rod handling machine 16.

The fuel rod storage box 19 separated from the fuel rod handling machine 16 is carried by a cart 17.18 through the entrance 35 provided in the lower wall of the reactor containment vessel 3 on the side of the spent fuel storage pool 6. The spent fuel rods 20 in the storage box 19 are transferred to a predetermined storage location by the delivery boat 15. The entrance 35 is equipped with a reactor side door and a spent fuel storage pool side door, so that the water in the spent fuel storage pool 6 flows into the lower space 35 of the reactor containment vessel.
In order to prevent water from flowing into the tank, one of the doors is kept closed when the carts 17 and 18 pass.

Loading of new fuel rods is performed by reversing the above procedure.

In the above configuration, the height of the fuel rod handling machine 16 can be suppressed to approximately 1.5 times the length of the fuel rods, and the height of the fuel rod storage box 19 can be suppressed to a level slightly longer than the length of the fuel rods. Therefore, as a whole, the height H' shown in FIG. 2 can be made much smaller than the height H in the conventional example shown in FIG. Its earthquake resistance can be improved. Furthermore, unlike the conventional example, it is possible to install multiple fuel transfer carts 17, 18 and fuel rod storage boxes 19.
In that case, the fuel exchange time can be further shortened.In addition, in Fig. 2, water may also be filled in the transfer passage 36 of the fuel rod storage box 19 at the bottom of the reactor containment vessel. It is not necessary to open and close the door of the loading port 35 during transfer, and it has the effect of shortening the fuel exchange time. It also helps prevent accidents caused by accidental dropping of fuel rods during fuel exchange, and This has the effect of increasing the weight of the building and improving the earthquake resistance of the building.

〔Effect of the invention〕

According to the present invention, when the refueling equipment of a pressure tube reactor is simplified, the co-inclined refueling work process is simplified, the refueling time is shortened, and the fuel rods fall during the work. The chances of an accident occurring can be reduced. In addition, there is no need to provide an underground waterway in the foundation mat, which is advantageous for its structure, strength, and construction work, and the height of the fuel handling device and fuel storage box does not need to be so large compared to the length of the fuel rods. Therefore, the height of the space required for fuel exchange can be made smaller than before, and as a result, the earthquake resistance of the building can be improved and the building can be made more compact.

[Brief explanation of the drawing]

FIG. 1 shows a conventional example of a fuel exchange machine and a dedicated space for fuel transfer inside a pressure tube nuclear reactor building. FIG. 2 shows equipment for fuel exchange and a fuel transfer space inside a building of a pressure tube nuclear reactor according to an embodiment of the present invention. FIG. 3 shows a schematic structure of a fuel rod handling machine and a fuel rod storage box in an embodiment of the present invention, FIG. 4 shows details of part A in FIG. 3, and FIG. A BB cross section is shown. Figures 6 to 10 show the operating conditions of the fuel rod handling machine and the fuel rod storage box. 1...Pressure tube reactor 2...Pressure pipe 3...Reactor containment vessel 4...Foundation mat 5...Underground waterway
6... Spent fuel storage pool 8... Traveling trolley
9...Traversing trolley 10...Fuel exchange machine 11
...Snout 12...Input/output boat 13...Fuel rod in/out gripper 14...Underwater transfer trolley 15...Delivery boat 16...Fuel rod handling machine 17...Traveling trolley 18...Transverse trolley 19...Fuel rod storage box 20
... Fuel rod 21 ... Lifting chain 22 ...
・Lower shielding plug storage case 23...Fuel rod entry/exit rod 24...Motor 25...Rotating shaft 26...
Arm plate 27... pedestal 28... lower tube
29...Snout 30...Elevating chain 31.
...Spring 32...Hydraulic cylinder 33...Connecting pipe 3
4...Motor 35...Inlet port 36...Transfer path Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 Fig. 7 Fig. 8 Fig. 9 Fig. 10

Claims (1)

[Claims] A first mobile transport device having a degree of freedom of movement in two horizontal directions, which can be located directly under any pressure pipe of a pressure tube type nuclear reactor installed in a reactor building; a second movable conveyance device installed at a lower level than the first movable conveyance device, which can be removably connected to the lower end of any of the pressure pipes supported by the first movable conveyance device; A fuel rod handling device for moving fuel in and out of the pipe; a fuel rod handling device supported by the second mobile transport device and detachably connected to the lower end of the fuel handling device to receive and receive fuel rods from the fuel rod handling device; a rod storage box, and the horizontally movable second mobile transport device and the fuel storage box supported thereon from a transfer port connecting the lower reactor area in the building and the spent fuel storage pool. Fuel exchange equipment for a pressure tube nuclear reactor, which is characterized by: