JPS5813159Y2 - Buffer support device used in a highly radioactive atmosphere - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for supporting structures in an atmosphere with high radiation levels.

Equipment used in an atmosphere with high radiation levels must be able to withstand the effects of that radiation.

For example, atomic couplants are required to have high safety against earthquakes due to their nature.

One of the most important parts of a nuclear couplant is the reactor vessel that houses the source reactor core, and coolant piping is connected to the vessel.

Since such piping is susceptible to vibration, it is supported by a support device in a building housing the piping.

Since various problems will occur if the supported structure, such as piping, is not allowed to move at all, the support device has a function that only restrains specific movements that may cause problems due to the strength of the piping, such as sudden vibrations during an earthquake. is required, and therefore a damping support device is used.

Hydraulic or mechanical shock absorbers have traditionally been used, but in environments with high levels of radioactivity, their components, such as hydraulic oil and sealing pads, are exposed to radiation. In addition, human access to the installation location of the device is restricted to avoid radiation damage, so it cannot be used.

An example of an atmosphere with high levels of radiation is around the reactor vessel of a fast breeder reactor.

This invention was devised in view of the above-mentioned circumstances.
It is an object of the present invention to provide a buffer support device that does not suffer from radiation damage even when used in a radiation atmosphere of a bell.

Hereinafter, the present invention will be explained based on the illustrated embodiments.

In FIGS. 1 and 2, side walls 1a, lb.

1(!, 1d, and a ceiling plate 1e) is fixed to the floor 2 of the building by suitable means such as anchor bolts (not shown) passing through a flange 1g extending outward from a horizontal bottom plate 1f. .

A side wall 1a having an opening 3 at the top and a side wall 1 facing it
In b, there are cylindrical members, that is, round bars 5 that are facing each other and are concentric.
a and 5b are fixed, and the same round bar 5a.

5b is connected to these by a connecting rod 6 which is coaxial and has a circular cross section.

The cylinder 7 has circumferential grooves 7a and 7b on both ends of its inner peripheral surface,
It fits into the round bars 5a and 5b and has a circumferential groove 7a.

It is slidably supported via piston rings 9a and 9b inserted into piston ring 7b.

The inner edge of the partition member, that is, the partition plate 11 extending inward from the center of the cylinder 7 terminates close to the connecting rod 6, and the piston ring 14 is inserted into the circumferential groove 12 of the partition plate 11.
It is in contact with the surface of the connecting rod 6 via.

A space 16 formed by the round bars 5a, 5b, the connecting rod 6 and the cylinder I is connected to the partition plate 11 and the piston ring 14.
It is divided into two pressure chambers 16a and 16b.

FIG. 3 shows the details of the assembly of the piston ring 14, in which a small gap 21 is formed between both ends, and the pressure chambers 16a and 16b are slightly in communication via the gap 21.

Instead of the gap 21, a thin through hole (not shown) may be formed in the partition plate 11.

Lips 23a and 2 extending from the side walls 1c and 1d of the tank 1
A support rod 27 is slidably supported by a boss 25 integrally formed with the support rod 3b and extends through the opening 3 in parallel with the axis of the round rods 5a and 5b (sliding force direction of the cylinder 7). The end communicates with cylinder 7 as shown.

The tank 1 is filled with liquid metal, ie, mercury 32, with a liquid level indicated by 31, and an inert gas is filled above the liquid level 31.

Bellows seal 35 interposed between side wall 1a and support rod 27
This isolates the inside and outside of the tank 1.

The other end of the support rod 27 connects to a primary coolant pipe of a fast breeder reactor (not shown) to horizontally support it, and the outside of the tank 1 is filled with inert gas during operation of the reactor.

The pressure chambers 16a, 16b are filled with liquid metal, ie mercury 32.

Piston rings 9a, 9b, 14 are made of steel.

In this embodiment having the above-described configuration, the pipes supported in the horizontal direction by the support rods 27 move slowly when the plant is started or stopped, or due to thermal expansion, etc.
When the cylinder 7 moves, for example, to the right in the figure, the cylinder I slides on the surfaces of the round bars 5a and 5b in the right direction.

As a result, the partition plate 11 also moves to the right, and the pressure chamber 16
The pressure of mercury in a increases, and the mercury moves to the pressure chamber 16b through the gap 12 of the piston ring 14.

Since there is no gap between the piston rings 9a and 9b under normal conditions, the mercury in the pressure chambers 16a and 16b does not leak to the outside of the cylinder 1.

When the moving speed of the piping and thus of the partition plate 11 is low, the resistance when the mercury 32 passes through the gap 21 is -1 JbJz, and its movement is not restricted.

On the other hand, if the piping moves rapidly, such as during an earthquake, the movement will be from support rod 2T → cylinder 7 →
The mercury is transmitted sequentially to the partition plate 11, but because the speed at which the mercury passes through the gap 21 is high, its resistance becomes large, preventing rapid displacement of the partition plate 11 and, in turn, the piping, and restraining the piping.

Mercury 32 and steel piston ring 9alb-14 are not damaged by radiation.

According to this embodiment having the above-described configuration and operation, gradual displacement of the piping during normal operation of the plant is allowed, while rapid displacement of the piping during an abnormality such as an earthquake occurs due to the resistance of mercury. This is prevented by increasing the amount of force, so that the piping can be restrained and supported with an appropriate amount of force when necessary.

Furthermore, mercury 32 and steel piston ring 9a.

9b and 14 are not damaged even when exposed to high levels of radiation, so they retain their function for long periods of time even in high-level radiation atmospheres, and can not only properly support the piping, but also be able to Piston rings 9a, 9 due to side
Even if the bellows seal 35 is damaged or the bellows seal 35 is damaged, since the pressure chambers 16a and 16b are below the liquid level 31 of the mercury 32, loss of the mercury 32 in the pressure chambers 16a and 16b is prevented, and repair is possible. It can perform its function for a sufficient long period without any need.

Furthermore, under normal conditions, the mercury 32 reciprocates between the pressure chambers i6a and 16b and does not circulate inside or outside the cylinder 7.
The liquid level 31 can be maintained at the lowest position, the entire device can be made compact, there are fewer restrictions on the installation space, and the piping can be appropriately supported.

Although the embodiments for supporting piping have been described above, the structure to be supported is not limited to the piping described above, and it is possible to support structures that need to avoid sudden displacement and vibration. Any suitable liquid metal can be used, such as an alloy of potassium and potassium.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of the present invention, FIG. 2 is a sectional view taken along line A--A in FIG. 1, and FIG. 3 is a partially enlarged view of FIG. 1. 1...tank, 1a, 1b, IC91d...
...Side wall, 1e...Ceiling board, 1f...
・Bottom plate, 1g...Flange, 3...Opening, 5a, 5b...Round bar, 6...-Connecting rod, 7...Cylinder , 7a, 7b... Circumferential groove, 9a, 9b... Piston ring, 11.
...Partition plate, 12...Circumferential groove, 14...
... Piston ring, 16 ... Space, 16
a, 16b...--Pressure chamber, 21...Gap, 27...Support rod, 31...Liquid level, 3
2...Mercury.

Claims (1)

[Scope of utility model registration request] A sealed tank containing liquid metal, a cylindrical member extending horizontally and fixed within the liquid metal of the tank, a cylinder surrounding the cylindrical member and slidably fitted into the cylindrical member; a seal ring fitted to both ends of the inner peripheral surface of the cylinder; and a horizontal support member having one end fixed to the cylinder and extending in the sliding direction of the cylinder through the outer shell of the tank. , characterized in that a thin through hole is bored in a partition member that extends inward from the inner surface of the cylinder and partitions the space formed between the columnar member and the cylinder into at least two pressure chambers. A buffer support device used in a highly radioactive atmosphere.