JPH0325196Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention relates to a handling tool used when transporting reactor internals such as an upper core structure and a lower core structure into and out of a nuclear reactor vessel. It is.

[Prior Art] In conventional handling tools of this kind, for example, when lifting reactor internals from a reactor vessel, an alignment tool is installed upright on the flange surface of the reactor vessel from which the lid has been removed in advance. The guide bush of the handling tool is fitted into the pin, and while positioning the handling tool, the handling tool is gradually lowered to the flange surface of the reactor internals, and the handling tool is connected to the reactor internals. were connected using special joints, and then the handling tools were lifted to lift the reactor internals. Furthermore, the lowering of the reactor internals into the reactor vessel was performed in the reverse order to the above.

However, when the guide bush rises and separates from the alignment pins as the reactor internals are lifted by the handling tool, the lower part of the reactor internals is still inside the reactor vessel. When lowering objects, the lower part of the reactor internals has already begun to enter the reactor vessel before the guide bushings engage with the alignment pins. Since there are situations in which objects are not positioned with respect to the reactor vessel, interference between the reactor vessel and the reactor internals may occur, resulting in damage to the reactor internals.

In particular, it is difficult to adequately monitor the lifting and lowering of reactor internals after the start of operation of the reactor, as this is done underwater, and there is a high possibility of interference between the reactor internals and the reactor vessel. . Therefore, in order to avoid interference, lifting and lowering operations must be carried out extremely carefully, leading to problems such as an increase in reactor shutdown time and an increase in radiation exposure for workers due to the extension of the work time.

[Problems to be solved by the invention] Therefore, conventional handling tools have the potential to cause damage due to interference between the reactor vessel and the reactor internals, and to prevent interference, the work time may be extended. There were various problems such as increased reactor shutdown time and increased radiation exposure for workers. The present invention aims to solve such problems.

[Means for Solving the Problems] For this purpose, the reactor internal structure handling tool according to the present invention has a means for detachably engaging the reactor internal structure, and is capable of being hung by a crane. a main body, a fixed guide provided on the main body so as to be able to engage with an alignment pin vertically installed on a flange surface of the reactor vessel, and an operating rod provided on the main body so as to be extendable and retractable in the longitudinal direction; The operating rod is arranged in alignment in the axial direction below the fixed guide so as to be able to engage with the alignment pin, and is detachably engaged with the lower end of the operating rod. The movable guide is movable with respect to the fixed guide.

[Function] The movable guide is provided to prevent mutual interference between the reactor vessel and the reactor internals due to a narrow gap when lifting and lowering the reactor internals. In other words, when lifting the reactor internals from the reactor vessel, when the fixed guide above the movable guide leaves the alignment pin, the lower part of the reactor internals is in the narrow space between it and the reactor vessel. Although it is passing through the gap, since the movable guide located below is guided by the alignment pin, there will be no interference between the reactor vessel and the reactor internals. On the contrary, when the reactor internals are suspended from the reactor vessel, when the movable guide is inserted into the alignment pin 42, the reactor internals are still in the narrow gap between them and the reactor vessel. has not been reached. Through such action, the intended purpose can be achieved.

[Embodiments] Next, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings, in which the same reference numerals indicate the same or corresponding parts.

FIG. 1 is a side view of the handling tool of the present invention, FIG. 2 is a plan view, and FIG. 3 is a sectional view particularly showing the extension/retraction mechanism and attachment/detachment mechanism of the movable guide. 1 and 2, the handling tool of the present invention includes a triangular workbench 23 to which a handrail 24 is attached, and the workbench 2.
3 is a triangular spreader 1 suspended by six workbench support columns 20 (only two are shown in the figure).
8 and an annular support ring 6 suspended from the spreader 18 by three support columns 10 (only two are shown in the figure), and these structures form the main body framework of the handling tool. It consists of

The support column 10 is attached to the support ring 6 with a bolt (not shown) and then welded to the fixing metal fitting 32.
(Fig. 3). Three lower U-rings 19 are attached to the spreader 18, and the workbench 2
Three corresponding upper U-rings 22 are attached to the block ring 25 projecting above the block ring 3, and each pair of corresponding U-rigs 19, 22 is firmly connected by a connecting rod 21, respectively. Therefore, by suspending the block ring 25 using a crane or the like (not shown), the handling tool of the present invention can be lifted and lowered.

1 to 3, the support ring 6 has a fixed guide or upper guide bush 5 in a radially outwardly projecting position. This support ring 6
As can be understood from FIG. 3, a protection ring 1 having a larger diameter than the support ring 6 is arranged in a manner described later in order to cover the sealing surface, that is, the flange surface, of the reactor vessel 41. The protective ring 1 is provided with a lower guide bush 2 which is axially aligned with the upper guide bush 5. In this embodiment, the guard ring 1 and the lower guide bush 2 form a movable guide that is movable with respect to the fixed guide.

Inside the hollow support column 10, an operating rod 13 extends in the axial direction, which can be operated from the workbench 23 at the upper end and which can be engaged with a reactor internal structure, which will be described later, at the engaging means at the lower end, that is, the engaging part 4. ing. The handling tool detachably engages with the reactor internal structure at this engaging portion 4 .

Further, as can be understood from FIGS. 1 and 3, and FIG. 3A showing the cross section taken along the line A-A, the support column 10 has bushings inside the lower guide 7 and the upper guide 8 attached thereto. Outer cylinder 9 via 29, 31
is slidably held, and the protective ring 1 is provided with three adapters 3 for hanging the protective ring 1 at positions aligned in the axial direction with this outer cylinder 9. As shown in FIG. 3, the adapter 3 has a groove 3a, into which a pin 27 provided at the lower end of the operating rod 12 extending in the axial direction inside the outer cylinder 9 can be engaged and detached. This allows the protective ring 1 to be attached and detached from the handling tool body. That is, when the three operating rods 12 are pushed downward and rotated by 90 degrees by operating the handle 38 from above the workbench 23, the pin 27 is engaged with the groove 3a of the adapter 3, and the protective ring 1 is moved together with the handling tool body. It becomes possible to lift and lower.

The operating rod 12 is held by the outer cylinder 9 and a guide tube 14 welded to the lower part of the workbench 23.
is always biased upward by a spring 30 inside. The lower end of the spring 30 is received by a plug 28 at the bottom of the outer cylinder 9. The protective ring 1 extends downward with respect to the handling tool body until the cap 11 provided at the top of the outer cylinder 9 reaches the upper guide 8 (in the embodiment, a distance approximately half the axial length of the support column 10).
It is movable. When the handling tool is not in use, it is preferable to attach the holding fitting 40 (FIG. 3) in the recess of the outer cylinder 9 in the state shown in FIG. 1 to prevent the outer cylinder 9 and the operating rod 12 from falling.

The operation of the above-mentioned handling tool will be described later, but when lifting and lowering only the upper core structure 43, the handling tool is used with the holding fitting 40 attached to the outer cylinder 9. Lower core structure 45
When carrying out the lifting and lowering work, the holding fitting 40 is removed and the outer cylinder 9 and the protective ring 1 are used in a state in which they can both be moved downward.

Next, the action of the handling tool of the present invention is shown in Figures 4 to 9.
This will be explained with reference to the figures.

In FIG. 4, in order to suspend only the upper core structure 43, the handling tool shown in the front view in FIG.
Lifted by a crane (not shown), reactor vessel 41
The lower guide bush 2 of the handling tool is attached to the alignment pin 42 vertically installed on the seal surface or flange surface of the
This shows the point in time when the upper guide bush 5 and the upper guide bush 5 are inserted. At this time, since the control rod drive shaft 44 protruding above the upper core structure 43 is located within the diameter of the annular support ring 6, it does not interfere with the lowering of the handling tool.

FIG. 5 shows that the handling tool is further lowered from the state shown in FIG. Shows the state connected to.
After this state, the handle 38 is operated on the workbench 23, and the pin 27 of the operating rod 12, which was engaged with the adapter 3 welded to the protective ring 1, is removed from the adapter 3.
When the operating rod 12, which is constantly pushed upward by the spring 30 inside the outer cylinder 9, moves upward together with the pin 27, the protective ring 1 is separated from the handling tool, and the reactor vessel It is placed on the flange surface of 41.

FIG. 6 shows a state in which the handling tool and the upper core structure 43 are lifted upward by a crane from the state shown in FIG. The protective ring 1 remains on the flange surface of the reactor vessel 41, and the upper core structure 43 is guided and suspended by the upper guide bush 5 inserted into the alignment pin 42 while being held by the engaging part 4 of the operating rod 13. Served.

FIG. 7 shows the state before the lower core structure 45 is lifted out following the upper core structure 43. From this state, the axes of the upper guide bush 5 and alignment pin 42 of the handling tool are aligned, and the handling tool is gradually lowered. At this time, since the holding fitting 40 has already been removed from the outer cylinder 9, the outer cylinder 9
The cap 11 has been lowered to the position shown where it engages the upper guide 8.

In FIG. 8, the handling tool is lowered further from the position shown in FIG. The state is shown in which the connection is made, and then the handle 38 is operated on the workbench 23, and the pin 27 of the operating rod 12 is inserted into the groove 3a of the adapter 3 welded to the protective ring 1 and locked.

FIG. 9 shows a state in which the handling tool is lifted upward from the state shown in FIG. As the lower core structure 45 is lifted from the state shown in FIG. , 2 are both guided by the alignment pin 42, and when the upper guide bush 5 comes off the alignment pin 42, it is guided only by the lower guide bush 2,
The lower core structure 45 is lifted out without interfering with the reactor vessel 41.

When lowering the lower core structure 45 and the upper core structure 43, the lowering is carried out in the reverse order of lifting from the state shown in FIG. 9 to the state shown in FIG. That is, in FIG. 9, when the lower core structure 45 is lowered, the lower guide bush 2 attached to the protective ring 1 extends downward;
At the time when the lower guide bush 2 is inserted into the alignment pin 42, there is a sufficient gap between the reactor vessel 41 and the lower core structure 45 to prevent interference. When the handling tool is further lowered, the lower guide bush 2 fits into the alignment pin 42 and is guided, so that the reactor vessel 41 is inserted into the reactor vessel 41 even before the upper guide bush 5 is inserted into the alignment pin 42.
Although the gap between the lower core structure 45 and the lower core structure 45 becomes narrower, the lower core structure 45 is suspended without interfering with the reactor vessel 41.

As described above, the lower guide bush 2 is provided to prevent mutual interference due to the narrow gap between the reactor vessel 41 and the lower core structure 45 when the lower core structure 45 is lifted and lowered. . That is, from the reactor vessel 41 to the lower core structure 4
5, when the upper guide bushing 5 leaves the alignment pin 42, the lower part of the lower core structure 45 is passing through the narrow gap between it and the reactor vessel 41;
are guided by the alignment pins 42, so that interference between the reactor vessel 41 and the lower core structure 45 does not occur. On the contrary, reactor vessel 41
When lowering the lower core structure 45, the lower core structure 45 has not yet reached the narrow gap between it and the reactor vessel 41 when the lower guide bushing 2 is inserted into the alignment pin 42. .

[Effects of the invention] By providing an extendable movable guide according to the invention, it is possible to prevent interference between the reactor internals and the reactor vessel due to the narrow gap between them, and to prevent It is possible to eliminate the difficulty of lifting and lowering structures, further shorten the work time, shorten reactor shutdown time, and reduce radiation exposure for workers.

[Brief explanation of drawings]

Fig. 1 is a front view showing the overall configuration of the handling tool according to the present invention, Fig. 2 is a plan view of the handling tool shown in Fig. 1, and Fig. 3 is a telescopic mechanism and attachment/detachment mechanism of the movable guide of the handling tool. 3A is a sectional view showing the 3rd
4 to 9 are explanatory diagrams showing various states during operation of the handling tool of the present invention. Figure 5 is a diagram when the upper core structure is lifted (hanged down), showing the state in which it has been carried into the reactor vessel.
Figure 6 shows the state in which the upper core structure is lifted (hanged down), Figure 7 shows the state before the lower core structure is lifted out, and Figure 8 shows the handling tools installed on the reactor vessel flange surface. Figure 9 shows the lower core structure being lifted (hanged down).
It is a figure showing a state. DESCRIPTION OF SYMBOLS 1... Protective ring, 2... Lower guide bush, 4... Engaging means, 5... Upper guide bush, 10... Support column, 12... Operating rod, 18...
Spreader, 21... Connecting rod, 25... Block ring, 41... Reactor vessel, 42... Alignment pin, 43... Upper core structure, 45...
Lower core structure.

Claims (1)

[Scope of Claim for Utility Model Registration] A handling tool for lifting and lowering the reactor internals of a reactor vessel, which has a means for detachably engaging the reactor internals, and is capable of being used by a crane. a main body that can be hung; a fixed guide provided on the main body so as to be engageable with an alignment pin vertically provided on a flange surface of the reactor vessel; and a fixed guide provided on the main body so as to be extendable and contractable in the longitudinal direction. an operating rod disposed in axial alignment below the fixed guide so as to be engageable with the alignment pin;
A tool for handling reactor internals, comprising: a movable guide that is movable with respect to the fixed guide and that detachably engages with the lower end of the operating rod.