JPH0139560B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a channel attachment device that facilitates attachment of a channel box to a fuel assembly.

Generally, the fuel assembly of a boiling water reactor includes a large number of fuel rods 3 and water rods 4 arranged in a rectangular shape between a lower tie plate 1 and an upper tie plate 2, as shown in FIG. The main body is composed of a plurality of spacers 5 that bind these fuel rods 3 and water rods 4 at regular intervals. A channel box 7 is attached to the outer periphery of the fuel assembly 6, and the channel box 7 is fixed to the upper ends of projections 8 formed at the four corners of the upper tie plate 2 by fasteners 9.

Note that a handle 10 is formed on the upper tie plate 2, and a protrusion 11 is formed on the handle 10.

The channel box 7 can be easily removed from the fuel assembly 6 by removing the fasteners 9 fixing the channel box 7 to the upper tie plate 2 and pulling the channel box 7 upward.

However, when attaching the channel box 7 to the fuel assembly 6, it is necessary to position all four corners of the lower end of the square channel box 7 outside the four protrusions 8 of the upper tie plate 2. There is, and it is very difficult.

That is, when inspecting the fuel rods 3 for damage or thermal deformation of the channel box 7, for example, the channel box 7 is pulled out from the submerged fuel assembly 6 and inspected, and then the channel box 7 is submerged again. In this case, it is necessary to attach it to the fuel assembly 6 by remote control, but this attachment is extremely difficult.

The present invention has been made in response to such conventional circumstances, and includes a jig main body whose lower surface has an outer diameter equal to the diagonal length of an upper tie plate having a rectangular shape and whose upper end is tapered, and this jig. Projection holes formed on the lower surface of the main body into which two diagonally formed projections are inserted among the projections formed at the four corners of the upper tie plate, and an operation that is removably fixed to the upper end of the jig main body. It is an object of the present invention to provide a channel device device characterized in that it consists of a pole.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the present invention will be described below with reference to an embodiment shown in the drawings.

The channel mounting device 12 shown in FIG. 2 is composed of a channel mounting jig 13 and an operating pole 14 detachably fixed to the upper end of the channel mounting jig 13.

Further, as shown in FIGS. 4 and 5, the channel installation jig 13 includes a jig main body 17 having a tapered cross section, and the operating pole 14 is inserted into the top of the jig main body 17. circular recess 18
is formed. A J-shaped groove 19 is formed in the recess 18, and a groove 19 is formed in the recess 18.
The other end of the spring 21, on which the disk 20 is placed at the upper end, is in contact with the bottom surface.

As shown in FIGS. 4 and 6, a handle hole 22 is formed in the center of the lower surface of the jig main body 17, into which the handle 10 formed on the upper tie plate 2 is inserted, and at both ends of the lower surface, A protrusion hole 23 into which the protrusion 8 of the upper tie plate 2 is inserted is bored. Note that the projections 11 provided on the handle 10 are inserted into grooves 24 formed at both ends of the handle hole 22 and perpendicular to the handle hole 22.

The channel attachment device configured as described above is used as described below.

That is, first, the protrusion 1 at the tip of the operation pole 14
6 into the groove 19 of the channel mounting jig 13 and twisting the operating pole 14 to the left to secure the operating pole 14 to the channel mounting jig 13. Then, while holding the operating pole 14 by hand, for example, As shown in FIG. 7, the channel mounting tool is moved to the upper part of the fuel assembly 6 placed in water, and the channel mounting jig 13 is fitted onto the upper tie plate 2. Thereafter, as shown in FIG. 8, the operating pole 14 is removed from the channel mounting jig 13, and the channel box 7 is gently fitted into the channel mounting jig 13. And after being fitted,
By simply pressing the channel box 7 as it is, the channel box 7 is guided by the curved surface formed on the jig main body 17 and is smoothly fitted into the fuel assembly 6.

As described above, according to the present invention, the channel box can be attached to the fuel assembly in a short time and with good workability, and the upper part of the fuel assembly and the lower part of the channel box are not damaged.

[Brief explanation of drawings]

FIG. 1 is a partially cutaway perspective view showing one embodiment of a fuel assembly, FIG. 2 is a perspective view of a channel installation device of the present invention, and FIG. 3 is a perspective view of the operating pole shown in FIG. 2. , FIG. 4 is a longitudinal sectional view of the channel mounting jig shown in FIG. 2, FIG. 5 is a top view of FIG. 4,
FIG. 6 is a bottom view of FIG. 4, and FIGS. 7 and 8 are explanatory diagrams for explaining how to use the channel attachment device shown in FIG. 2. 2...Upper tie plate, 8...Protrusion, 14...Operation pole, 17...Jig body, 23...Protrusion hole.

Claims (1)

[Claims] 1. A jig body whose lower surface has an outer diameter equal to the length of a diagonal line of an upper tie plate having a rectangular shape and a tapered upper end; A channel mounting device comprising a projection hole into which two diagonally formed projections are inserted, and an operation pole detachably fixed to the upper end of the jig main body.