JPS58144789A - Fuel storage rack for 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 The present invention relates to a high-density fuel rack for nine-atomic diesel engines.

In nuclear couplants, spent fuel removed from the reactor core is temporarily stored until it is reprocessed. In recent years, improvements have been made to shorten the distance between stored fuels in order to effectively utilize the space within the spent fuel pool, and racks based on this idea are called high-density racks. The rack needs to be structured so that the fuels do not reach criticality due to mutual influence), and a neutron absorbing material is inserted between the fuels to minimize the spacing between them. In addition, since the rack stores fuel, it is an important piece of equipment in terms of earthquake resistance, and its strength must be sufficient.

As shown in Fig. 1 and Fig. 2, in the conventional rack, corners ml are assembled to form an upper reinforcing member 2, middle reinforcing members 3 and 4.
, is considered to be an integral part of Base 5. Also, the square tube l is the outer tube 6.
, an inner cylinder 7, a neutron absorber 8, and a spacer 9, and has a triple structure. Here, as the neutron absorbing material, Boral (a mixture of B4C and aluminum 9m and sintered) is used. In the case of such a rack, the manufacturing tolerance of the square tube becomes significant, the manufacturing efficiency is poor, seal welding is required at the top and bottom ends of the square tube, and the wall thickness increases and the weight increases by 4, so it is necessary to increase the density of the rack. It is not possible to aim for

An object of the present invention is to provide a fuel rack for a nuclear reactor that can be easily increased in density.

The present invention eliminates the need for a conventional outer cylinder by winding a long material made of a neutron absorbing material around the outer periphery of the cylinder, making it easier to manufacture and reducing the wall thickness. It is something.

Hereinafter, the present invention will be described in detail based on the attached vAIij.

In FIGS. 3 to 7, an amorphous alloy ribbon 11 is spirally wound around the outer periphery of a corner 11i1100.

The amorphous alloy ribbon is wound in a multilayered manner as shown in FIG. 5, and the amorphous alloy ribbons 11 do not overlap each other between the layers.

A part of the corner of the rectangular cylinder lO is formed round, and the amorphous alloy ribbon 11 wound around this corner part is fixed to the rectangular cylinder lO by a bottle 12.

In this embodiment, an amorphous alloy thin layer 11 is provided on the outer periphery of the rectangular tube 10.
41 neutron absorbers consisting of 11 are surrounded. Amorphous alloys can be formed into extremely thin strips and have excellent toughness and corrosion resistance. For example, even if an amorphous alloy ribbon is constantly brought into contact with approximately 550% pure water, no corrosion will occur. Therefore, when winding the amorphous alloy ribbon around the rectangular tube 10, stress (tensile stress) can be applied, so it can be tightly wound and the work is simple. Also, when used as a fuel storage rack, corrosion of the amorphous alloy ribbon does not pose a problem. Next, it is necessary for the amorphous alloy ribbon to have neutron absorption ability, but in general, amorphous alloys contain one or more of B, P, C, and Si or 2s or more before becoming amorphous. It is formed by ultra-quenching and solidifying molten metal containing these in a liquid state. In particular, boron has a high neutron absorption ability, and in this case, the distribution of boron in the thin plate is completely uniform because it is ultra-quenched, and the neutron absorption ability is high. Furthermore, in general, crevice corrosion is likely to occur when a single barrier is formed in a neutron absorbing material, but as shown in FIG.
Since Ichinoseki does not occur in the wound state of , it is highly effective in preventing Ichinoseki corrosion.

FIG. 7 shows a plan view of a storage rack for nine nuclear reactors using the rectangular tubes shown in FIGS. 3 to 6. In FIG. 7, the amorphous alloy ribbon 11 is wound seven times between the upper reinforcing material 20 and the nine-sided tube 10 (11
7) are arranged, and these rectangular tubes 100 are arranged.
A rectangular tube in which amorphous alloy ribbons 11 are not wound alternately between the tubes.
10 (indicated by B in FIG. 7) are arranged. In such an arrangement of the rectangular tubes 10, a portion of the corner of each rectangular tube 10 is formed round, so that the corner 5taII of each rectangular tube 10 can be formed without being restricted by the bottle 12. Since a neutron absorbing material is interposed between the fuel in each rectangular tube, it is possible to maintain the subcriticality of the fuel.

In the above embodiment, a thin ribbon made of an amorphous alloy is used, and a wire made of an amorphous alloy is wound around a rectangular tube. However, thin strips are more advantageous in terms of workability during winding and prevention of gap formation. Furthermore, 41 in the square tube
The member to be rotated is not limited to an amorphous alloy, but any member can be used as long as it has a neutron absorption ability and has strength and toughness that do not interfere with the winding operation.

As described above, according to the present invention, it is sufficient to simply wrap the neutron absorbing material around the outer periphery of the cylindrical body constituting the fuel storage rack for a nuclear reactor, so the work is easy and an outer cylinder is not required. High density can be achieved by reducing the size and weight of the cylinder.

[Brief explanation of the drawing]

Figure 1 is a front view of a conventional nuclear reactor fuel storage rack;
The figure is a sectional view of a square tube used in the rack of FIG. 1, FIG. 3 is a sectional view showing an example of a square tube in the present invention, FIG. 4 is a plan view of FIG. 3, and FIG. FIG. 6 is an enlarged sectional view taken along the line A-A, FIG. 6 is an enlarged view of the Australian part of FIG. 4, and FIG. 7 is a plan view of a fuel gauge X rack showing an example of the present invention. 10... Square tube, 11... Amorphous alloy ribbon, 12...
·bottle. Figure 2 Figure 4

Claims (1)

[Scope of Claims] 1. In a reactor fuel storage rack, a raw material equipped with a round cylindrical body that holds a plurality of fuel-electric combinations in an upright state at predetermined intervals is placed in a reactor fuel storage rack, and neutrons are applied to the outer periphery of the cylindrical body. A nuclear reactor fuel storage rack characterized by winding a long length of absorbent material. 2. The fuel storage rack for a nuclear reactor according to claim 1, wherein the elongated material is an amorphous alloy ribbon. 3.4111! A fuel storage rack for a nuclear reactor, characterized in that a plurality of the elongated materials are piled up in a helical shape and wound nine times in the first item or the snowy item of the FIII requirement.