JPS5933869B2 - How to store the connecting waterway gate of a radioactive waste storage pool - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for storing a waterway gate used in transferring stored radioactive waste between a plurality of radioactive waste storage pools in a nuclear power plant or nuclear fuel reprocessing facility.

A radioactive waste storage pool (hereinafter referred to as a pool) is a rectangular box-shaped structure with thick concrete side walls and a bottom, for the purpose of attenuating the radioactivity of spent nuclear fuel, used control rods, and radioactive waste. The inner surfaces of the side walls and bottom are lined with stainless steel plates to maintain watertightness.

A pool generally consists of a combination of multiple pools, and the multiple pools are connected to each other via a waterway for transporting stored materials, and when water leaks in one pool or when the pool is inspected, the pools are connected to each other through the waterway. The storage radioactive waste is arranged so that it can be easily transferred underwater to other pools.

An example of the arrangement and structure of a conventional pool is shown in FIGS. 1 and 2 in the case where two pools are connected.

Figure 1 is a plan view showing two pools connected by a waterway, and Figure 2 is a vertical cross-sectional view of the pool when the hoist moves the radioactive waste and reaches the middle of the waterway. It is.

Pool 1 and pool 2 are connected by a waterway 3 as shown in FIG.

The waterway 3 has a gate 4 and a gate 5, and the pools 1, 2, and the waterway 3 are filled with water for radiation shielding.

The gates 4 and 5 are plate-shaped and have a hoist 15 (second
The hanging portions of the hooks 16 shown in the figure are fixed and come into close contact with the vertical watertight portions 7 and 7' of the partition walls 6 of the pools 1 and 2, thereby preventing communication between the pools 1 and 2.

There are also storage grids 9, 9' at the bottoms 8 and 8' of the pools 1 and 2, in which the radioactive waste 10 is stored.

The transport of stored radioactive waste 10 will now be described.

Although not shown in FIG. 1, the soil on the rail 14 installed horizontally on the poolside 13 (FIG. 2) is lifted up from the position shown by the solid line using the hook 16 of the freely moving portal hoist 15. With the gate more than half submerged in water, it is moved to position 11 shown by the dashed line next to the partition wall 6 and stored, and the gate 5 is similarly moved to position 12 shown by the dashed line and stored, and the waterway 3 open.

Next, the stored radioactive waste 10 to be moved is similarly lifted from the storage grate 9 of the pool 1 using the hoist 15 so that it is entirely underwater, and is then quietly moved underwater and passed through the waterway 3. and placed in a designated storage grid 9' at the bottom 8' of the pool 2.

As mentioned above, in order to open the waterway 3, the gates 4 and 5 must be moved and stored, which requires a large space within the pools 1 and 2, and the radioactive waste 10 is placed near the waterway 3. This is a loss in space utilization for each pool.

In addition, when the stored radioactive waste 10 passes through the waterway 3, there is a risk that the hoist 15 may accidentally explode or collide with the side wall of the narrow waterway 3 due to vibrations during an earthquake or movement.

This invention takes into consideration the drawbacks of the conventional gate moving and storing method, which has the above-mentioned losses and risks, and makes it possible to safely store a large amount of radioactive waste in a limited space. To provide a method for moving and storing a gate so as not to damage the waterway wall by colliding with it when moving from one pool to another, and to protect the waterway wall.

An embodiment of the invention will be described with reference to FIGS. 3 to 5.

FIG. 3 shows a state in which the water channel 3 is closed, and differs from FIG. 1 in that the pools 1 and 2 are provided with storage grids 9 and 9' up to the vicinity of the water channel 3.

To move the gates 4 and 5, use the hoist 15 to lift each gate so that it is more than half underwater, move it slightly away from the watertight parts 7 and 7', and rotate it slightly within its horizontal plane. While moving it into the waterway 3, its vertical surface is almost in contact with the vertical surface of the waterway wall 17° 17', and the fasteners protruding perpendicularly from the vertical surface are attached to the soil edges of each of the gates 1-4 and 5. The gates 4 and 5 are lowered by the hoist 15 until the lower surface of the portion 18 comes into contact with the horizontal upper end surface of the receiving portion 19 which is integrally provided at the upper end of both side walls of the water channel 3, and the gates 4 and 5 are lowered by the bolt 20. Each receiving part 19
It is removably fastened and fixed.

As a result, both side walls of the waterway 3 are protected by the gates 4 and 5, which are easy to repair and replace.

As explained above, by adopting the gate storage method for a radioactive waste storage pool of the present invention, it is possible to effectively use the space that was previously unusable and required for the conventional gate storage position and gate movement. becomes possible,
In addition, it prevents damage to the channel wall due to collision between the radioactive waste and the channel wall when passing through a narrow channel, which occurs when moving radioactive waste conventionally stored in pools, and even if a collision occurs, the channel wall can be prevented from being damaged. Since the wall is protected by a gate, it is the gate that is damaged and can be immediately pulled up and repaired or replaced.

This means more storage space allows more radioactive waste to be stored safely, and the stainless steel plate lining on the channel walls keeps the radioactive waste watertight when moving the stored radioactive waste in the pool. You can safely move it without damaging it.

[Brief explanation of the drawing]

Figure 1 is a plan view of two radioactive waste storage pools connected by a waterway, showing the closed state of the gate and the open and retracted state of the conventional gate, and Figure 2 shows the radioactive waste storage pool. In longitudinal section, from one radioactive waste storage pool,
3, 4 and 5 are plan views and longitudinal sections of the radioactive waste storage pool when the method of the present invention is carried out. FIG. 3 shows the gate in a closed state, and FIG. 4-5 shows the gate in an open and retracted state. 1.2...Radioactive waste storage pool, 3...
...Waterway, 4,5...Gate, 15...
...lifting machine.

Claims (1)

[Claims] 1. At both ends of a waterway that connects multiple adjacent radioactive waste storage pools and has sufficient space to move radioactive waste underwater, plate gates are installed to open and close the waterway, with both ends of the waterway closed. A hoist installed above the waterway in the pool moves the gate to a position where the vertical flat side surface of the gate is almost in contact with the vertical sidewall of the waterway, and at that position, the gate is detachably attached to the sidewall of the waterway. How to store the connecting waterway gate of the radioactive waste storage pool to be concluded.