JPS60263891A - Fast breeder reactor - 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 [Technical Field of the Invention] The present invention relates to a fast breeder reactor with an improved vibration damping structure for damping horizontal vibrations of a reactor core.

[Technical Background of the Invention] A conventional example will be explained with reference to FIG. The code 1 in the figure is
A reactor vessel is shown, and inside this reactor vessel 1 there is a coolant 2.
and a reactor core 3 are housed therein.

The reactor core 3 is composed of a plurality of fuel assemblies, control rods, etc. (not shown). Further, a roof slab 4 is installed so as to close the upper opening 1A of the reactor vessel 1. This roof slab 4 includes a fixed plug 4A fixed in the reactor vessel, a large rotating plug 4B rotatably installed on the inner circumferential side of this fixed plug 4A, and a large rotating plug 4B rotatable on the inner circumferential side of this large rotating plug 4B. It consists of a small rotation plug 4C installed in the. The above reactor vessel 1
A safety container 5 is installed on the outer periphery of the reactor vessel 1, and in the event that the reactor vessel 1 is damaged and the coolant 2 inside leaks, the safety container 5 will contain the leaked coolant 2. Coolant 2
This structure prevents the leakage of water to the outside and the occurrence of secondary disasters due to this.

Note that the safety vessel 5 has a skirt portion 5A in the reactor building 6.
The reactor vessel 1 is supported by the reactor building 6 together with the roof slab 2 via a ring gutter 7. The reactor core 4 is accommodated and supported by a core support mechanism 8 that is erected from a mirror portion 1B within the reactor vessel 1. A core upper mechanism 9 is installed above the core 4, passing through the small rotating plug 4C.

A partition wall "11" is installed between the core support mechanism 8 and the heat shielding part 10 installed on the inner circumferential side of the reactor vessel 1. The upper part is a high-temperature, high-pressure upper plenum 12, and the lower part is a low-temperature, low-pressure lower plenum 13. Also, between the core support mechanism 8 and the reactor vessel 1, an intermediate heat exchanger 14 and .

A circulation pump 15 is connected to the fixed plug 4A and the partition wall 11.
They are installed alternately at equal intervals in the circumferential direction.

A core vibration damping member 16 is installed between the reactor C> support structure 8 and the reactor vessel 1 at a position below the distance M111. The core vibration damping member 16 effectively controls the horizontal vibration of the core 4 and the core support mechanism 8 when a horizontal earthquake occurs, for example, to maintain the integrity of the core. A radial key mechanism 17 is interposed between the core vibration damping member 16 and the core support mechanism 8, and this radial key mechanism 17 allows the difference in thermal expansion between the core vibration damping member 16 and the core support mechanism 8 to be This structure absorbs the energy and damps the vibration of the core 3 without restricting the thermal expansion of both.

[Problems with Background Art] According to the above configuration, a horizontal load acts on the radial key mechanism 17 when an earthquake occurs, for example.
This is a heavy load, and since it is installed immersed in the high-temperature coolant 2, the radial key mechanism 16 will wear out and become galled.

There is a risk that local deformation may occur, and the design is designed accordingly.

Even in the manufacturing process, the above-mentioned wear and the like had to be taken into consideration, which was difficult.

[Purpose of the invention]

The present invention has been made based on the above points, and its purpose is to solve various problems that occur in mechanical coupling structures such as the above-mentioned radial key mechanism, and to solve design and manufacturing problems. The object of the present invention is to provide a fast breeder reactor that can overcome these difficulties.

[Summary of the invention]

In other words, the fast breeder reactor according to the present invention includes a reactor vessel that houses a coolant and a reactor core therein, a roof slab that is installed to close the upper opening of the reactor vessel, and a A core support mechanism that is erected from the lower part and supports the reactor core so as to accommodate the reactor core, and at least one of the outer circumferential side of the core support mechanism and the inner circumferential side of the reactor vessel is formed on one side, and the reactor core is supported by the fluid force of the coolant. This configuration includes a core vibration damping region that suppresses horizontal vibrations of the core.

[Embodiments of the invention]

A first embodiment of the present invention will be described below with reference to FIG. Note that parts that are the same as those in the prior art are denoted by the same reference numerals, and their explanations will be omitted. FIG. 1 is a vertical sectional view showing a schematic configuration of a fast breeder reactor according to this embodiment. On the outer peripheral side of the core support mechanism 8, a fluid oscillator cylinder 101 is installed concentrically with a certain gap 102 between them. The fluid damping cylinder 101 is supported by a core vibration damping member 16 extending from the reactor vessel 1 toward the core support mechanism 8, and its upper and lower ends are free ends. By installing such a fluid damping cylinder 101 on the outer peripheral side of the core support mechanism 8, the fluid force of the coolant 2 located in the gap 102 causes the core 3 and the reactor core 3 to
This structure restricts the horizontal vibration of the core support mechanism 8 that houses the core support mechanism 8.

According to the above configuration, when a horizontal earthquake occurs, for example, a relative displacement occurs between the reactor core 3 side and the fluid oscillating cylinder 101 side. At that time, the coolant 2 in the gap 102
A flow field is generated, and fluid force acts on the fluid oscillating tube 101 and the core support mechanism 8 due to this flow field.

If the vibration system is evaluated by assuming, for example, that the flow of the coolant 2 in the gap 102 is a potential source, this fluid force becomes a so-called mass rate generating system. In this mass attainment system, the vibration modes of the reactor core 3 and the fluid oscillator 101 generally exhibit negative phase in the first mode and in phase in the second mode. Furthermore, the occurrence of such a mode depends on the size of the gap 102, the length of the gap 102 in the axial direction, the rigidity of the fluid oscillating cylinder 101, and the like. Each element such as the size of the gap 102, the axial length of the gap 102, and the rigidity of the fluid oscillating cylinder 101,
Appropriate evaluation makes it difficult for the reverse phase mode to occur and enables effective support of the core support mechanism 8 that accommodates the reactor core 3.

As described above, according to this embodiment, by installing the fluid oscillator 101 on the outer circumferential side of the core support mechanism 8 through the gap 102, it is possible to prevent the core 3 and the core support mechanism 8 from becoming horizontal when a horizontal earthquake occurs, for example. It becomes possible to effectively control the vibration in the direction by the fluid force of the coolant 2 within the gap 102, and the integrity of the core 3 can be maintained reliably. In addition, in the case of a vibration damping structure using the fluid vibration cylinder 101, a mechanical coupling structure such as a conventional radial key mechanism is not required, so problems that arise when a mechanical coupling structure is used, such as wear and galling, are eliminated. 1, local deformation, etc. can be eliminated, and there is no need to consider such various conditions at the design and manufacturing stages, making it easier.

Next, a second embodiment will be described with reference to FIG.

A certain gap 112 is provided on the inner peripheral side of the chain portion 1B of the reactor vessel 1.
A fluid vibration container 111 is installed. The fluid vibration vessel 111 is supported by a core vibration damping member 16 extending from the core support mechanism 8 in the direction of the reactor vessel 1 . That is, in the first embodiment, the core vibration damping region was formed on the outer peripheral side of the core support mechanism 8, whereas in this second embodiment, the core vibration damping region was formed on the outer peripheral side of the core support mechanism 8.
In this embodiment, a core vibration damping area is formed on the inner circumferential side of the chain portion 1B of the reactor vessel 1, and the fluid force of the coolant 2 in the reactor vessel 1 is used to create a reactor core 3 and a core support mechanism that accommodates the core 3. This configuration attempts to restrict the horizontal vibration of 8.

According to the above configuration, similarly to the first embodiment, the gap 11
2 and the rigidity of the fluid vibration vessel 111, the fluid force of the coolant 2 in the gap 112 can be used to stabilize the reactor core 3 and the core support mechanism 8 horizontally in the event of a horizontal earthquake, etc. It becomes possible to effectively restrict directional vibrations, and the integrity of the core 3 and the core support mechanism 8 can be maintained reliably. In addition, since no mechanical coupling structure is employed, the same effects as the first embodiment can be achieved, such as being able to solve the problems that would arise when a conventional radial key mechanism is employed. It becomes possible.

Next, a third embodiment will be described with reference to FIG.

The number 121 in FIG. 3 indicates a fluid vibration bulkhead. This fluid vibration partition wall 121 has its lower end fixed to the core support mechanism 8, and has a lower cylindrical body 121A installed on the outer peripheral side of the core support mechanism 8 with a gap 122, and a lower cylindrical body 121A. Heat shielding part 1 from the upper end to the inner circumferential side of the reactor vessel 1
a partition wall 121B installed annularly extending in the 0 direction;
and an upper cylindrical body part 121C installed on the inner peripheral side of the heat shielding part 10 with a gap 213 extending upward from the partition wall part 121B. The partition wall part 1
21B is the partition wall 1 in the first and second embodiments.
The inside of the reactor vessel 1 is divided into upper and lower halves, and the upper part is divided into upper and lower blemishes 12. The lower part is called the lower Blenheim 13.

Further, a heat shielding plate 125 is installed above the partition wall 121B and supported by the partition wall 121B via a support member 126. This heat shielding plate 125 is configured to shield excessive heat from the upper blemish 12 side. This third
In the embodiment, the gap 122. between the lower cylindrical body 121A and the core support mechanism 8. The horizontal vibration of the core 3 and the core support mechanism 8 is effectively controlled by the fluid force of the coolant 2 in the gap 124 between the heat shielding part 10 and the upper cylindrical circumferential part 121G.

According to the above configuration, the gap 122 between the lower cylindrical body 121A of the fluid vibration partition wall 121 and the core support mechanism 8 and the gap 124 between the heat shielding part 10 and the upper cylindrical body 121C
The horizontal vibration of the core 3 and the core support mechanism 8 can be effectively restricted by the fluid force of the coolant 2 inside. In particular, the fluid vibration region is
Since it is formed on both sides of o, effective vibration damping can be achieved. Furthermore, since no mechanical coupling structure is employed, it is possible to achieve the same effects as the first and second embodiments, such as being able to eliminate problems that would otherwise occur when a mechanical coupling structure is employed.

Next, a fourth embodiment will be described with reference to FIG.

On the outer circumferential side of the core support mechanism 8, a double-structured fluid vibration damping double cylindrical structure 131 is suspended and supported by the core vibration damping member 16. This fluid oscillating double cylindrical structure 131 is
It is composed of an inner tube 131'A located on the core support mechanism 8 side and an outer tube 131B located on the outer peripheral side of the inner tube 131A. And these inner cylinder 131A and outer cylinder 1
31B, a cylindrical fluid vibration cylindrical support 133 is provided upright from the core support mechanism 8. The gaps 134 and 135 formed between the fluid vibration cylindrical bearing 133 and the inner tube 131A and the outer tube 131B have the same width in the radial direction and are constant in the axial direction. In this embodiment, the fluid force of the coolant 2 in the gaps 134 and 135 formed by the fluid vibration double cylindrical structure 131 and the fluid vibration cylindrical receiver 133 causes the core 3 and the core support mechanism 8 to This configuration effectively restricts vibrations in the horizontal direction.

According to the above configuration, the fluid-oscillating double cylindrical structure 131;
The gap 13 formed by the fluid vibration cylindrical receiver 133
The fluid force of the coolant 2 in the core 3 and the core support mechanism 8 can be effectively controlled by the fluid force of the coolant 2 in the core 3 and the core support mechanism 8. , it is possible to achieve the same effects as in the first to third embodiments, such as solving the problems that would occur when a mechanical coupling structure is employed.

Next, a fifth embodiment will be described with reference to FIG.

This fifth embodiment has a configuration that is a combination of the second and third embodiments, and a fluid vibration vessel 141 is installed on the inner peripheral side of the chain portion 1B of the reactor vessel 1. . Between this fluid vibration vessel 141 and the chain portion 1B of the reactor vessel 1,
A gap 142 is formed. This fluid shaking container 141
The upper end portion extends directly toward the core support mechanism 8 and serves as a core vibration damping member 143 . A fluid vibration partition wall 144 is installed from the core support mechanism 8. This fluid vibration partition wall 144 has the same configuration as the fluid vibration partition wall of the second embodiment, and includes a lower cylindrical body portion 144A,
It is composed of a partition wall part 144'B and an upper cylindrical body part 144C. The core vibration damping member 143 is integrally joined to the upper part of the lower cylindrical body 144A. Further, a gap 145 is formed between the lower cylindrical body 144A and the core support mechanism 8, and the upper cylindrical body 1
A gap 146 is formed between 44C and the heat shielding part 10. A heat shielding plate 1 is provided on the upper surface side of the partition wall portion 144B.
47 connects to the partition wall portion 144B via the support member 148.
It is supported and installed. In this embodiment, the regions that function as fluid vibration regions include a gap 142 between the fluid vibration container 141 and the chain portion 1B, a gap 145 between the lower cylindrical body portion 144A and the core support mechanism 8, and These are the regions of the gap 146 between the upper cylindrical circumferential portion 144C and the heat shielding portion 10.

According to the above configuration, similar to the first to fourth embodiments,
The fluid force of the coolant 2 in each region makes it possible to effectively control horizontal vibrations of the core 3 and core support mechanism 8, and also to prevent problems when a mechanical coupling structure is adopted. It is possible to eliminate everything.

Next, a sixth embodiment will be described with reference to FIG.

In this sixth embodiment, a fluid vibration vessel 151 is installed on the inner peripheral side of the mirror portion 1B of the reactor vessel 1 with a gap 152 interposed therebetween, and the lower end of the fluid vibration vessel 151 is connected to the reactor core. It is connected to the support mechanism 8.

Further, its upper end portion extends above the liquid level of the coolant 2. Reference numeral 153 in the figure indicates a fluid vibration partition wall, and this fluid vibration partition wall 153 is comprised of a lower cylindrical body 153A erected from the core support machine 411I8 and a lower cylindrical body 15
It consists of a partition part 153B extending downward from the upper end of the heat shielding part 10, and an upper cylindrical body part 153C extending upward from the partition part 153B. A gap 154 is formed between the lower cylindrical body 153A and the core support mechanism 8, and a gap 154 is formed between the upper cylindrical body 153C and the fluid vibration vessel 151.
55 is formed. In this embodiment, this gap 1.
54, 155 and the fluid force of the coolant 2 within the gap 152, this structure effectively restricts horizontal vibration of the core 3 and the core support mechanism 8.

According to the above configuration, the gaps 154, 155 and 15
Due to the fluid force of the coolant 2 in the reactor 2, horizontal vibrations of the core 3 and the core support mechanism 8 can be effectively restricted, and the integrity of the reactor core 3 can be significantly improved. In particular, three gaps 154 and 15 are used as core vibration damping areas.
5.152 is formed, the core 3 is more effectively
Also, vibration of the core support mechanism 8 can be damped. Furthermore, since a mechanical coupling structure unlike the conventional radial key structure is not employed, it is possible to eliminate the problems that would otherwise occur when a mechanical coupling structure is adopted.

Next, a seventh embodiment will be described with reference to FIG.

On the inner peripheral side of the chain portion 1B of the reactor vessel 1, there is a fluid vibration vessel 1.
61 are installed with a gap 162 between them. The lower end of this fluid vibration vessel 161 is connected to the core support mechanism 8 . Further, a core vibration damping member 163 is joined to the upper end of the fluid vibration vessel 161. Furthermore, this core vibration damping member 163 is joined to the upper end of a fluid vibration cylinder 164 installed on the outer peripheral side of the core support mechanism 8 . A gap 165 is formed between the fluid oscillating cylinder 164 and the core support mechanism 8. Above the core vibration damping member 163, there is a partition wall 1
66 are installed. Both ends of this partition wall 166 are connected to the core support mechanism 8 and the heat shield section 10, respectively. In this embodiment, the horizontal vibration of the core 3 and the core support mechanism 8 is effectively restricted by the fluid force of the coolant 2 within the gaps 162 and 165.

In the case of this seventh embodiment as well, it is possible to achieve the same effects as in the first to sixth embodiments.

Next, an eighth embodiment will be described with reference to FIG.

A fluid vibration structure 171 is installed in a torus shape with a gap 172 on the inner peripheral side of the chain portion 1B of the reactor vessel 1. In addition, at the bottom of this fluid vibration structure 171,
A seal plate 174 is installed with a gap 173 between it and the core support mechanism 8 . This seal plate 174 and the fluid vibration structure 171 form a low temperature region 176 (corresponding to the lower brenum 13), and the fluid vibration structure 171 and the seal plate 174 also have a function as a so-called partition wall. are doing. A heat shielding plate 177 is installed above the fluid vibration structure 171, and both ends of the heat shielding plate 177 are supported by the core support mechanism 8 and the heat shielding part 10 via support members 178 and 179. has been done. In the case of this embodiment, the gap 17 formed between the fluid vibration structure 171 and the chain portion 1B of the reactor vessel 1
The structure is such that the horizontal vibration of the core 3 and the core support mechanism 8 is effectively restricted by the fluid force of the coolant 2 in the core 2 .

Therefore, the same effects as those of the first to seventh embodiments can be achieved, and the structure can be simplified since the fluid vibration structure and structural part 171 also have a function as a partition wall. becomes possible.

Next, a ninth embodiment will be described with reference to FIG.

This ninth embodiment is based on the partition wall 1 in the first embodiment.
1 is located below the core vibration damping member 16, and a heat shielding plate 182 is installed above the core vibration damping member 16. In the case of this ninth embodiment as well, the gap 102 formed between the fluid system imaging cylinder 101 and the core support mechanism 8 is similar to the case of the first embodiment.
This configuration effectively restricts horizontal vibrations of the core 3 and core support mechanism 8 by the fluid force of the coolant 2 inside.

Therefore, the same effects as in the first embodiment can be achieved, and the partition wall 181 can be protected. Note that the core vibration damping member 1G and the fluid damping cylinder 101 are located in the upper plenum 12, but the heat shield plate 1
By installing 81, it becomes possible to sufficiently avoid the influence of heat.

Next, a tenth embodiment will be described with reference to FIG. In this tenth embodiment, a seal plate 191 is installed below the fluid vibration member 16 in the fourth embodiment, and this seal plate 191 functions as a partition wall, and the fluid vibration The upper part of the double cylindrical structure 131 is filled with gas 192. Further, a heat shielding plate 193 is installed above the fluid vibration member 16 . The heat shield plate 193 is supported at both ends by the core support mechanism 8 and the heat shield part 10 via support members 194 and 195, respectively. In other words, the fluid-oscillating double cylindrical structure 1
By filling gas 192 in 31, the space between upper plenum 12 and lower plenum 13, which are divided into two by the seal plate 191, is sealed. In the case of the tenth embodiment, the core vibration damping region is formed between the fluid damping double cylindrical structure 131 and the fluid secondary transport cylindrical receiver 133, as in the fourth embodiment. The structure is such that horizontal vibrations of the core 3 and the core support mechanism 8 are effectively restricted by the fluid force of the coolant 2 within these gaps 134 and 135. .

Therefore, the same effects as those of the first to ninth embodiments can be achieved, and since the structure also functions as a partition, the structure can be simplified.

〔Effect of the invention〕

As detailed above, the fast breeder reactor according to the present invention includes a reactor vessel that houses a coolant and a reactor core therein, a roof slab installed to close the upper opening of the reactor vessel, and A core support mechanism that is erected from the lower part of the vessel and supports the reactor core so as to accommodate the reactor core, and a core support mechanism that is formed on at least one of the outer circumferential side of the core support mechanism and the inner circumferential side of the reactor vessel to allow the flow of coolant. This structure includes a core vibration damping area that controls horizontal vibrations of the core using physical strength.

Therefore, without adopting a mechanical coupling structure as in the past, the fluid force of the coolant in the core vibration damping area can effectively suppress vibrations in the horizontal direction of the core and the core support R that accommodates and supports the core. As a result, it is possible to eliminate the problems caused by conventional mechanical coupling structures, and improve the core vibration damping function.
design.

It also becomes possible to eliminate manufacturing difficulties.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of a tank-type fast breeder reactor showing a first embodiment of the present invention, FIG. 2 is a longitudinal sectional view of a tank-type fast breeder reactor showing a second embodiment, and FIG. FIG. 4 is a longitudinal cross-sectional view of a tank-type fast breeder reactor showing a fourth embodiment, and FIG. 5 is a tank-type fast breeder reactor showing a fifth embodiment. Figure 6 is a vertical cross-sectional view of a type fast breeder reactor.
FIG. 7 is a vertical cross-sectional view of a tank-type fast breeder reactor showing a seventh embodiment; FIG.
FIG. 8 is a longitudinal sectional view of a tank-type fast breeder reactor showing the eighth embodiment, FIG. 9 is a longitudinal sectional view of the tank-type fast breeder reactor showing the ninth embodiment, and FIG. 10 is a longitudinal sectional view of the tank-type fast breeder reactor showing the ninth embodiment. FIG. 11 is a longitudinal sectional view of a tank type fast breeder reactor showing an example of the conventional tank type fast breeder reactor. 1... Reactor vessel, 2... Coolant, 3... Reactor core,
4... Roof slab, 8... Core support mechanism, 101
... Fluid damping tube, 102... Gap (core vibration damping area)
. Applicant's Representative Patent Attorney Takehiko Suzue Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 M9rlA Figure 10

Claims (4)

[Claims] (1) A reactor vessel that accommodates coolant and a reactor core inside, a roof slab installed to close the upper opening of the reactor vessel, and a roof slab that is erected from the lower part of the reactor vessel to accommodate the reactor core. a core support mechanism that supports the core so as to accommodate the core;
A core vibration damping area is provided on at least one of the outer circumferential side of the core support mechanism and the inner circumferential side of the reactor vessel to damp horizontal movement of the core by the fluid force of the coolant. A fast breeder reactor featuring: (2) Claims characterized in that the core vibration damping region is formed by a core support mechanism and a fluid installation tube installed concentrically with the core support mechanism on the outer peripheral side of the core support mechanism. The fast breeder reactor according to paragraph 1. (3) The core vibration damping region is formed by a reactor vessel and a fluid vibration vessel installed on the inner peripheral side of the reactor vessel. fast breeder reactor. (4) The core vibration damping region is inserted from below into a fluid sub-transport double cylindrical structure and a fluid vibration damping double cylindrical structure which are suspended from the outer peripheral side of the core support mechanism and are composed of an inner cylinder and an outer cylinder. 2. The fast breeder reactor according to claim 1, wherein the fast breeder reactor is formed by a fluid oscillating vessel receiver.