JPH0225193Y2 - - Google Patents

Description

[Detailed description of the invention] [Technical field to which the invention pertains] The present invention is a high-temperature gas-cooled nuclear reactor that surrounds and stacks the in-core components arranged outside the reactor core and is arranged by an in-reactor restraint mechanism. The present invention relates to a support structure for a shield body for supporting a shield body to be tightened by a heat shield on the furnace internal components.

[Prior art and its problems] High-temperature gas-cooled nuclear reactor vessels that house reactor core structures are subject to temperature increases and material deterioration due to irradiation from the reactor core. Therefore, it is necessary to insert a shield between the reactor core structure and the reactor vessel to lower the irradiation level and prevent the above-mentioned temperature rise and material deterioration of the reactor vessel due to irradiation. .

FIG. 4 is a partial sectional view of a nuclear reactor showing a quarter core of a high-temperature gas reactor equipped with such a shell or shell.
In the figure, the fuel body, control body, etc. made of hexagonal columnar graphite are arranged in a honeycomb shape as the reactor internal components, and are shown as 1, around which reflectors 2 as the reactor components are arranged. form the reactor core,
It is arranged within the reactor vessel 10. Adjacent reflectors 2 are provided with keys 2a to maintain alignment. The shield bodies 3 are constructed by housing a shield body in a metal case, and are supported by the outer surface of the reflector 2 and arranged so as to surround the outer surface of the reactor core. A core restraint mechanism 4 is disposed between the core apparel 11 and the reactor core. The core restraint mechanism 4 surrounds the core by connecting restraint bands 4a. And band support 4b and support body 3
, and tightens the shield body 3 to the reflector 2 and simultaneously tightens the reactor core.

FIG. 5 is a plan view showing a structure for supporting a conventional stiffening body, and FIG.
FIG. In Figures 5 and 6, the reflector 2
A slot 2b is vertically provided in the side surface of the slot 2b, and the support leg 3a of the shield body 3 is supported by being rested on the bottom surface 2c of the slot 2b as shown in FIG. And the band support 4 of the core restraint mechanism 4
b is supported by a support plate 3b etc. attached to the shield body 3, and comes into contact with the shield body 3 through the liner 4c, and the core restraint mechanism 4 causes the shield body 3 to be attached to the reflector 2. It's tightened.

However, in the above structure, the reflector 2 is made of graphite, while the slot 2 of the reflector 2
Since the outer case of the shield body 6 inserted in b is made of metal, a difference in thermal expansion of the materials occurs due to the difference in their thermal expansion coefficients depending on the operating temperature of the reactor, and when tightening the shield body 2, Due to the thermal expansion of the insulation body, there is a possibility that a crack may form at the corner of the bottom surface 2c of the slot hole 2b of the insulation body 2, as indicated by the broken line 12, as shown in FIG. In addition, in FIG. 5, the distance between the groove of the key 2a and each corner of the slot 2b, which is shown by the broken line 11, is provided on the side of the reflector 2 to maintain the alignment in the event of an earthquake. This broken line 1
One part has the disadvantage of being easily damaged by stress.

[Purpose of invention]

In view of the above-mentioned drawbacks, the present invention has been developed to simplify the support structure of the shield body attached to the internal components on the outside of the reactor core, thereby making it difficult for damage to the internal components to occur, thereby increasing reliability. The purpose of the present invention is to provide a support structure for the flexible body that can improve the flexibility of the body.

[Summary of the idea]

According to the present invention, the shield body surrounding the furnace components is provided with a pair of support legs on the upper and lower sides of the side surface in contact with the furnace components, and the upper pair of support legs are provided with projections. A hole larger than the protrusion and sized to absorb the displacement of the protrusion due to thermal expansion of the shrinkage body is provided on the side surface of the furnace component opposite to the protrusion, The protrusion is loosely fitted into the hole of the component, and the support surface of the upper support leg is brought into contact with the side surface of the furnace component, and the support surface of the lower pair of support legs is brought into contact with the furnace component. This is achieved by a support structure that supports the flexible body by coming into contact with the side surface of the flexible body.

[Embodiments of the invention] Examples of the invention will be described below based on the drawings. FIG. 1 is a plan view showing a support structure for a stiffening body according to an embodiment of the present invention, FIG. 2 is a cross-sectional view taken along line A-A in FIG. 1, and FIG.
-B sectional view. In FIGS. 1 to 3, the same parts as in FIGS. 4 to 6 are designated by the same reference numerals. In FIGS. 1 and 2, a reflector 2 as an in-core component disposed at the outermost part of the reactor core is provided with a band support 4b of a core restraint mechanism 4.
The structure of each device, including the core restraint mechanism 4, the shield body 3, and the reflector 2, is the same as that described in the prior art section. However, in this embodiment, a pair of support legs 3c are provided at the same level on the upper part of the surface where the shield body 3 covers the outer peripheral surface of the reflector 2, and a pair of support legs 3d are provided at equal distances below each support leg 3c. . A projection 3e is provided on each of the upper pair of support legs 3c. The protrusions 3e are loosely fitted into holes 2c provided on the outer surface of the reflector 2, respectively. In other words, as shown in FIG.
is inserted into the hole 2c of the reflector 2 and supported by the projection 3e. Therefore, the outer surface of the reflector 2 has a surface 3f of a pair of support legs 3c having a protrusion 3e of a flexible body 3, and a pair of support legs 3d without a protrusion.
is in contact with the surface 3g.

The shape of the protrusion 3e of the support leg 3c is rectangular,
The shape of the hole 2c of the reflector 2 into which the protrusion 3e is loosely fitted is a rectangle larger than the protrusion 3e, and as shown in FIG. 3, gaps 2d and 2e are provided on the upper side and in the outer circumferential direction on the outside of the band support, respectively. Note that the depth of the hole 2c is also made larger than the height of the protrusion 3e to provide a gap. These gaps are sized to absorb and absorb the elongation due to the difference in thermal expansion coefficient between the reflector made of graphite and the case made of metal containing boron-containing graphite 5 (see Figure 2).

By tightening the shield body 3 and the reflector 2 having the above structure by the core restraint mechanism 4, the shield body 3 is supported by the reflector 2 by the protrusion 3e and supported by the support legs 3c and 3d. Side 3
Abuts on f and 3g, respectively.

Now, when the operating temperature is reached due to operation of the nuclear reactor, a difference in thermal expansion occurs between the shield body 3 and the reflector 2 due to the difference in materials. However, the support leg 3c of the stiff body
Since the protrusion 3e is loosely fitted into the hole 2c on the outer surface of the reflector with the above-mentioned gap, and the lower support leg 3d is flat, the elongation of the flexible body in the circumferential direction can be avoided. On the other hand, when the upper support leg 3c having the protrusion 3e is restrained, the elongation in the vertical direction is allowed to escape downward, and even when the lower support leg 3d is restrained, the extension is allowed to escape upward due to the loose fitting of the protrusion 3e. Therefore, as explained in the section of the prior art, there is little possibility of damage occurring longitudinally across the reflector 2 from the corner of the hole 2c.

Furthermore, since the hole 2c provided on the side surface of the reflector is relatively small and shallow, the distance between the keyway and the corner of the hole 2c, as explained in the prior art section, becomes relatively large. , which significantly reduces the possibility of damage due to stress in this part.

In addition, in the above, the support surfaces 3f and 3g of the support leg 3c
Although it is made to protrude from the case surface 3h of the shield body 3, the same effect can be obtained even if it is made on the same plane.

[Effect of idea]

As is clear from the above description, according to the present invention, at least a pair of protrusions protruding from the support legs above the shield body are provided on the outer surface of the reactor internal components disposed at the outer diameter of the reactor core. The upper support leg is loosely fitted into the hole with a gap that absorbs the difference in thermal expansion between the shield body and the furnace component, and the support surface of the upper support leg is brought into contact with the side surface of the furnace component. At the same time, by supporting the support surfaces of the lower pair of support legs in contact with the side surfaces of the in-reactor components, the shield body and the in-reactor components come into contact with each other during operation of the reactor. Even if a difference in thermal expansion occurs, the elongation of the flexible body can be escaped, so that the possibility of damage to the components in the furnace due to restraint of thermal expansion is significantly reduced. In addition, the holes provided on the side surfaces of the furnace components can be relatively small and shallow, so they can be used with grooves provided on the abutment surfaces of the furnace components, such as the corners of keyways for retaining the arrangement. The distance from the corner of the hole, that is, the distance, is longer than that of the prior art, and there is also the effect that the possibility of stress-induced damage occurring in this portion is significantly reduced.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing the supporting structure of the shield body according to the embodiment of the present invention, and FIG. 2 is an A in FIG. 1.
-A sectional view, FIG. 3 is a partial sectional view taken along line B-B in FIG. FIG. 6 is a sectional view taken along line CC in FIG. 5. 1: Fuel body as a component in the reactor, 2: Reflector as a component in the reactor, 2c: Hole, 3: Shrink body, 3c, 3d: Support leg, 3e: Projection, 3f, 3
g: Support surface.

Claims (1)

[Scope of utility model registration request] A plurality of shingles are stacked vertically to surround a plurality of in-core components arranged on the outer diameter side of the reactor core, and are arranged in a stacked manner in a vertical direction.A reactor restraint mechanism is used to tighten around these shingles. A support structure for supporting each of the shingle bodies on the reactor internal components of the high temperature gas cooled nuclear reactor, the support structure comprising: a support structure for supporting each of the shingle bodies on the reactor internal components, and comprising: a support structure that supports each of the shingle bodies on the top and bottom of the side surfaces of the shivering bodies that are in contact with the reactor internal components; A pair of support legs are provided, and the upper pair of support legs is provided with a protrusion, and the side surface of the furnace component opposite to the protrusion is provided with a A hole of a size that can absorb the displacement of the protrusion is provided, the protrusion is loosely fitted into the hole of the furnace component, and the support surface of the upper support leg is brought into contact with the side surface of the furnace component. . A supporting structure for a shield body, characterized in that the support surface of the lower pair of support legs is brought into contact with a side surface of the furnace internal component to support the shield body.