JPH0247717B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pressure tube nuclear reactor, and is particularly suitable for preventing vibrations of various guide tubes in a calandria tank that are prone to shake during an earthquake, and has improved ease of handling, manufacturing and installation. This invention relates to a vibration-proof structure for a guide pipe in a calandria tank, taking into account alignment workability.

Figure 1 shows the structure of a conventional pressure tube reactor.

This nuclear reactor consists of a calandria tank 1 that holds heavy water as a moderator, an iron water shield 3 installed around it that shields radiation and heat, and
It holds nuclear fuel and light water as a coolant, and is composed of calandria tubes 2 connected in a grid pattern to the upper and lower tube plates of a calandria tank 1 and a pressure tube assembly 5 passing through an iron water shield body 3. .

Note that the calandria tubes 2 arranged in a lattice shape are arranged in a forest, and a guide tube 6 for a control and measurement device for the nuclear reactor is installed between the lattice of the calandria tubes 2 arranged in a lattice shape.

This guide pipe 6 needs to be provided with an earthquake-resistant upper rest, and a vibration isolation plate 4 is installed inside the calandria tank 1 as a countermeasure.

The structure of the vibration isolating plate 4 is a disk shape, and holes for the guide tube 6 and the calandria tube 2 are provided. Since the calandria tube 2 structurally does not require a vibration isolation function, the gap between the calandria tube 2 and the hole for the calandria tube 2 made in the vibration isolation plate 4 is made large.

When the output of the nuclear reactor is small and the number of pressure tube assemblies 5 is small, the diameter of the calandria tank 1 and the diameter of the vibration isolator 4 will not be large, and they can be manufactured and installed using the conventional structure of the vibration isolator 4. There are no particular problems in terms of work or alignment work.

Note that the alignment work was performed by installing the vibration isolating plate 4 in the calandria tank 1 and then adjusting it by moving the entire vibration isolating plate 4. At this time, since the movement of the vibration isolating plate 4 is limited, there is a limit to the alignment with respect to each guide tube 6. Therefore, the hole diameter of the vibration isolating plate 4 is determined in consideration of manufacturing and installation tolerances of the guide tube 6 within a range that does not impair the vibration isolating function.

However, when increasing the output and increasing the size of the nuclear reactor, the diameter of the calandria tank 1 also increases, and the diameter of the vibration isolating plate 4 also inevitably increases.

Therefore, the vibration isolating plate 4 is connected to the calandria tank 1.
If installed inside, handling efficiency will be reduced. Further, when manufacturing a plate, it is impossible to manufacture a single plate, so it is necessary to join many plates together by welding, which reduces the productivity.

An object of the present invention is to provide a vibration isolation structure having a more effective vibration isolation function, which prevents a decrease in workability in manufacturing and installing vibration isolation plates as nuclear reactors increase in size.

The present invention targets only guide tubes that require anti-vibration measures, and includes a divided auxiliary ring on the outer periphery of the guide tube to prevent damage to the guide tube due to contact with the guide tube and to facilitate installation work. On the outside of this auxiliary ring, a ring divided into two parts is provided in two stages, upper and lower, in consideration of installation and alignment work. The directions of the upper and lower rings are shifted by 90 degrees, and the adjacent rings are connected by connecting rods, and the outermost ring and the calandria tank body are connected by connecting rods with adjustable length turnbuckles to connect them to the guide pipe. It has an anti-vibration structure that is characterized by anti-vibration measures.

FIGS. 2 to 7 show specific embodiments most suitable for implementing the vibration isolation structure according to the present invention.

FIG. 2 shows an example of the arrangement of the guide tubes 6 that require anti-vibration measures, and the guide tubes 6 are installed between grid intervals of a forest of calandria tubes 2.

FIG. 3 shows an example in which the vibration isolation structure according to the present invention is installed, in which the guide tubes are connected as shown in the figure,
It is supported by the calandria tank 1 via a turnbuckle 12. A detailed explanation of the vibration isolation structure according to the present invention will be given below.

4 and 5 show details of the structure of section A shown in FIG. 3.

In this example, an auxiliary ring 7 is installed on the outer periphery of the guide tube 6 and is divided into two parts for attachment after the guide tube 6 is installed. The auxiliary ring 7 is a part that comes into contact with the guide tube 6, and is made of the same material or a softer material than the guide tube 6 so that the outer surface of the guide tube 6 is less likely to be damaged due to contact between the auxiliary ring 7 and the guide tube 6.

Rings 8 and 9 are each divided as shown in the figure, and are placed on the outer circumference of the auxiliary ring 7 by 90 degrees at the top and bottom.
1. After the bolts and nuts 11 are tightened, they are prevented from rotating to prevent the bolts and nuts 11 from loosening during nuclear reactor operation, causing the rings 8 and 9 to come off and losing the vibration damping function.

Installing rings 8 and 9 separately into upper and lower parts is
This structure allows for easy alignment after installation, and since the vibration isolation support for each guide tube 6 can be done in two directions, alignment can be done at the optimal position for each row. It's getting old.

6 and 7 show details of the structure of section B shown in FIG. 3.

A connecting body 13 is attached to the calandria tank 1, and a connecting rod 10 is attached to it with bolts.
It is supported by a nut 14. Note that the bolt/nut 14 shall be prevented from rotating.

The connecting rod 10 connected to the guide tube 6 is connected by a turnbuckle 12 to a connecting rod 10 supported on a connecting body 13.

Since the body of the calandria tank 1 is a welded structure, the manufacturing tolerance for its diameter is large. Therefore, the turnbuckle 12 connects the conrod 10 between the calandria tank 1 and the guide pipe 6.
The length shall be adjusted. Also, at this time, the guide tubes 6 are aligned for each row.

It is assumed that the turnbuckle 12 and connecting rod 10 are prevented from rotating after alignment.

As described above, the present vibration isolation structure is easy to handle and install because each component is small in size and weight.

According to the present invention, there is an effect that the handling and installation work of the vibration isolating structure for the guide pipe in the calandria tank is facilitated.

[Brief explanation of drawings]

Figure 1 is a structural diagram of a conventional pressure tube reactor, Figure 2 is a layout diagram of a guide tube that requires vibration isolation, and Figure 3 is a diagram of the vibration isolation structure installed in the guide tube shown in Figure 2. Figure 4 is a detailed view of section A in Figure 3, and Figure 5 is a detailed view of section C in Figure 4.
6 is a detailed view of section B in FIG. 3, and FIG. 7 is a DD view in FIG. 6. 7...Auxiliary ring, 8...Ring, 9...Ring, 10...Conrod, 11...Bolt/Nut, 12...Turnbuckle, 13...Connection body,
14...Boruto Natsuto.

Claims (1)

[Claims] 1. In a guide tube installed in the calandria tank of a pressure tube reactor that requires a vibration isolation function, a divided auxiliary ring is attached to the outside of the guide tube, and a 90° shift upward and downward is attached to the outside of the guide tube. A vibration-proof structure characterized by attaching a split ring, connecting adjacent rings in two directions with connecting rods, and connecting the outermost connecting rod to a calandria tank via a turnbuckle.