JPS5948687A - Control rod guide tube support structure - 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 provides a support structure for a control rod guide tube that has a multi-tube structure in a pressure tube reactor.
The present invention relates to a structure suitable for ensuring sufficient properties and preventing large deformation.

The entire arrangement of control rod guide tubes in the upper part of the reactor of a conventional pressure tube Ji nuclear reactor is shown in FIG.

The control rod 1 is suspended by the middle upper wire rogue 3 of the control rod guide tube 2 and moves up and down. Misaki Keyaki g! The IHT device 4 is housed in a control rod storage caning 5 and fixed to a control rod drive device support structure 6. The control rod guide tube 2 is inserted into the lower end of the control rod drive unit storage casing 5 and connected via a bellows 7. Further, the guide pipe 2 is supported in two horizontal directions by a grating 8 on the way, and then passes through the upper iron water shed body 9.

It is fixed by welding to the upper tube plate lO of the calandria tank. Note that the inside of the guide tube 2 is filled with heavy water 11 for cooling.

The detailed structure of the part of the guide 1i2 in which the outlet piping group is arranged in the upper part of the TC slave furnace will be explained with reference to FIG. 2 and FIG. GA.

As shown in Fig. 4, in the upper part of a pressure '# type nuclear reactor, the distribution f# of the outlet piping 12 containing all the high temperature and high pressure fluid for extracting the heat of the reactor is densely arranged. A guide tube 2 stands up in the gap. The area around the distribution group f of the outlet piping 12 containing high-temperature and high-pressure fluid is #L-? It is composed of a heat insulating material 13 for the insulation and a heat insulating material support frame 14 for completely preventing the heat insulating material 13 from deforming. Therefore, distribution f#
Since the guide f2 inside is placed in a high temperature atmosphere, the guide -
It is wrapped in a cold insulating material 15 for keeping the cooling water 11 in the tit 2 cold.

In order to obtain a sufficient cooling effect from the cold insulating material 15, the thickness of the cold insulating material 15 must be approximately equal to the thickness, and therefore, the outer diameter of the guide tube 2 should be set to the same thickness as the pipes of the determined outlet power distribution group. It will be limited by the pinch of 12. i. The inner diameter of the guide tube 2 is such that the control rod 1, which is suspended by a wire rope 3 and moves up and down smoothly, has a diameter t of light for the sake of reactor shutdown, as required by the design. Since this is necessary, it is subject to restrictions. Therefore, the wall thickness of the guide tube 2 cannot exceed a certain value, which makes it impossible to ensure the rigidity of the guide tube 2). The control rod 1l17) for stopping the nuclear reactor may be caused to have an adverse effect on the insertability due to the deformation during the swing ltb of 2.

Furthermore, the fact that the wall thickness of guide/a2 is more than a certain value is considered to be unfavorable.
In the accident 4 when the outlet pipe 12 broke, the broken pipe swung around), the guide pipe was severely deformed due to the center of the guide pipe 2, and the problem was that the reactor would be in a bad shape rather than shutting down.

Furthermore, the installation of the cold insulating material 15 to the outer periphery of the millet inner pipe 2 of the control 41i is not easy and takes time because the work space within the outlet pipe group 2 before the control 715 control lIi guide is narrow. Rarely.

In order to eliminate the drawbacks of the above technology, in the outlet piping group? 1111## A control m guide tube in which the guide tube 2 has a multi-tube structure will be explained with reference to FIGS. 5 to 9.

The portion arranged within the outlet piping group has a triple pipe structure. These three pipes are integrally closed with a circular mound 16 at the upper part of the heat insulation support frame 14, and the lower end is connected to the outer and inner pipes by a socket 17 at the upper part of the bellows 7. 1
9 is integrated and closed. The lower end of the central tube 20 forms a gap with the socket 17, and communicates between the circular passage for the cooling fluid and the external electric passage. Further, a nozzle 21 for introducing cooling fluid and a nozzle 22 for discharging cooling fluid are connected to the upper end side surfaces of the central tube 20 and the outer tube 18, respectively.

Furthermore, a lug 23 is attached to the central chamber 20 to increase the rigidity of the triple pipe.

This has the effect of increasing the rigidity of the outlet piping portion of the control rod guide tube and eliminating the work of installing the cold insulation material.

However, since this structure has a triple-pipe structure, the upper part of the socket 17 is heavy, and this part shakes during vibrations such as earthquakes, causing the welded part of the socket 17 and inner pipe 19 as shown in Fg in FIG. In addition, there are disadvantages in that stress is applied and that the control rods for shutting down the reactor can be inserted into a bad shape.

The purpose of Kimi's Akira is to eliminate the drawbacks of the above-mentioned conventional technology and to provide a support for the control rod guide tube consisting of a multi-layered structure that can greatly prevent the vibration of the inner tube when the P control rods are connected to the ground. It's about providing structure.

In order to achieve the above object, in the present invention.

Connect the cylinder to the outside of the socket at the bottom end of the multiplex tube.

The cylinder is characterized in that the lower part of the control mIl guide tube is supported.

An embodiment of the present invention is shown below with reference to FIGS. 10 and 11.)
explain.

Reference numeral 9 indicates an upper iron/water layer shield body provided for the purpose of layer shielding and heat insulation. Inside it, there is a calandria tank (not shown) filled with water, which is a moderator, and a pressure pipe assembly (not shown) containing fuel is installed completely through it. ing. Several six pressure tube fruit combinations were installed closely together.

It forms the reactor core. Above the pressure tube fruit assembly.

The outlet pipes 12 are connected to each other, and the cooling water is sent from the pressure tube assembly to the outlet pipe group. Also, the cooling water is
The outlet pipe group is covered with a heat insulating material 13 and a heat retaining support frame 14 in order to be heated while passing through the fruit and vegetable joints and to maintain the high temperature even after being sent to the outlet pipe group.

A guide tube 2 with a multi-tube structure that guides the reactor control ## (not shown) is connected to a control rod drive device housing casing (not shown).
The control rod drive unit support structure (not shown) with a (not shown) when welding f! It has been fixed. The guide tube 2
Dozens of control rods are placed in the gaps between the pressure pipes and the joints, which are several sigma of pressure rods.

A socket 17 is attached to the lower end of the multi-tube structure in #2 in the thread, and a cylinder 25 is welded to the outside of the socket 17.

The cylinder 25 has a thickness that reduces the gap between the control rod guide tube 114 and the bellows cover in contact with the lower part of the control rod guide tube by an optical amount, and also has a thickness that reduces the gap between the control rod guide tube and the upper iron water shield 9. The length has a small gap that does not completely suppress thermal deformation.

According to the non-structural method, by making the gigang between the cylinder 25 and the bellows cover 224 as small as possible, it is possible to suppress the horizontal movement of the guide tube during an earthquake. Therefore, the rigidity of the lower part of the guide tube can be sufficiently increased.

As described above, in the present invention, by welding and attaching a cylinder to the outside of the lower end of the multi-tube structure of the control rod guide tube, the horizontal rigidity of the guide tube can be ensured by a light amount. This has the effect of ensuring the insertion curve of the control rods to shut down the reactor when the guide tube vibrates due to vibrations, etc.

[Brief explanation of drawings]

Figure 1 is a layout diagram of the control rod guide tube in the upper part of the pressure tube wall reactor.
Figure 2 is a detailed view of the part where the outlet piping group in the upper part of the reactor is arranged, Figure 43 is a sectional view taken along A-Ad in Figure 2, and Figure 4 is a diagram of the guide pipe and outlet power distribution in the upper part of the reactor. Figure 5 is an explanatory diagram of the guide tube constituting the triple pipe; Figure 6 is a diagram showing the positional relationship;
The figure is a sectional view taken along the line B-D in Figure 5, and Figure 7 is a cross-sectional view taken along the line C-C in Figure 6.
8 is a sectional view taken along line D-D in FIG. 6, FIG. 9 is an enlarged view of the upper part of FIG. 6, and FIGS. 10 and 11 are sectional views showing one embodiment of the present invention. be. 1...control 1 salary, 2...control 44! Guide tube, 3...
・Wire rope, 4... Control rod excitation device, butt... Control rod drive device storage couching, 6... Control rod drive device support structure. 7... Bellows, 8... Grating, 9... Upper iron water shield body, lO... Upper front plate of calandria tank. 11...Heavy water, 12...Outlet piping, 13...Heat insulation material. 14...Heat insulation support frame, 15...Cold insulation material, 16...
Round burial mound, 17...'/'jr7to, 18...outer tube%
19...Inner pipe %20...Central pipe, 21...Introduction nozzle, 22...Discharge nozzle Xk, 23...Rough %2
4...Bellows cover, 25...Cylinder. No. / Concave No. 2 Camellia 31! l No. 4 Kokyo S Mebō 6th country 7th day 8th country No. 9 Figure 70 Maro No. /l country

Claims (1)

[Claims] 1. The control rod guide tube located at the location where the reactor outlet piping group of the pressure tube reactor is located has a fully multiple tube structure, and the outer tube and inner tube are integrated with a socket at the lower end above the bellows. In the three control rod guide tubes that are closed and blocked,
A support structure for a control rod guide tube, in which a cylinder is attached to the outside of the socket, and the lower part of the control rod guide tube is supported by the cylinder.