JPS6056288A - 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] Kiyomi is about fast breeder reactors.

[Technical background of the invention]

A conventional example will be explained with reference to FIG. FIG. 1 is a schematic diagram of a tank-type fast breeder reactor. In the figure, 1 indicates the reactor vessel. A coolant 2 is housed within the reactor vessel 1 . A roof slab 3 is provided to close the upper opening IA of the reactor vessel 1. A reactor core 4 is installed within the reactor vessel 1 and is comprised of a plurality of fuel assemblies (not shown), control rods (not shown), and the like. This core 4 is accommodated and supported by a core support mechanism 5. The core support mechanism 5 containing the reactor core 4 is quickly lowered from the roof slab 3 by a wrapper 7. This hanging barrel 7 has an open lower lower A formed therein. Above the core 4, a core upper mechanism 8 penetrates the roof slab 3,
The roof slab 3 (2) is supported by the roof slab 3. In other words, the core support mechanism 5 housing the reactor core 4 and the core upper mechanism 8 are both supported by the roof slab 3, so that, for example, vertical seismic motion may occur. However, the relative displacement between the core support mechanism 5 housing the core 4 and the core upper mechanism 8 is extremely small.Therefore, it is possible to prevent a situation in which the control rods are misaligned and the core output fluctuates. In addition, a horizontal vibration damping member 9 is provided between the core support mechanism 5 and the reactor vessel 1 (= indicates horizontal vibration damping member 9 for suppressing the horizontal vibration of the core 4 and the core support mechanism 5. A partition wall 1] is provided between the hanging shell 7 and the partition wall 1o provided on the inner peripheral side C2 of the reactor vessel 1 above the vibration damping member 9.Then, this partition wall III=therefore, the inside of the reactor vessel 1 is divided into upper and lower halves, with the upper part being an upper blemish 12 and the lower part being a lower blemish 13.Then, an intermediate heat exchanger having an inlet 14k and an outlet 14B is formed between the IT1 cylinder 7 and the reactor vessel 1. 14 and a circulation pump 15 are provided that penetrate the roof slab 3 and the partition wall 11 and are supported by the roof slab 3. A seal mechanism 16 is provided between the intermediate heat exchanger 14 and the partition wall 11. 12 side of the upper blenheim and the lower blennium 1
The third side is sealed. The sealing mechanism 16 is attached to the corner wall 1
1 and the lower outer periphery of the intermediate heat exchanger 14 (=consisting of thin plates 17 and 18 provided respectively and a bellows 19 provided between the thin plates 17 and 18).

According to the fast breeder reactor having the above-mentioned configuration, the coolant 2 flows through the reactor core 4 from the bottom to the top, and the temperature rises at that time.

Then, the coolant 2 flowing into the suspension shell 7 from the core 4
The water flows out of the marking cylinder 7 through the open lower A of the printing cylinder 7, and flows into the intermediate heat exchanger 14 through the inlet 14A.

The coolant then exchanges heat with the secondary coolant in the intermediate heat exchanger 14, and flows out into the lower blenheim 13 from the outlet 14B. Then, it is pressurized by the circulation pump 15 and sent downward to the core 4 again.

[Problems with background technology]

According to the above configuration, the partition wall 1 includes the partition wall 10 and the hanging body 7.
The reactor vessel 1 is provided in a completely connected state, forming both a thermal boundary and a pressure boundary between the upper and lower parts of the reactor vessel 1.

For example, when a vertical or horizontal seismic motion occurs, the core 4 and the core support mechanism 5 vibrate in the vertical or horizontal direction. At this time, there is a risk that high stress may occur at the joints between the partition wall 11, the partition wall 10, and the hanging body 7.

In addition, there is a risk that thermal stress may occur due to the occurrence of severe temperature distribution (particularly in the vicinity of the joint with the lifting cylinder 7).

[Purpose of the invention]

The purpose of the present invention is to reduce the stress generated in the bulkhead due to vertical and horizontal displacement of the core and core support mechanism, and to reduce the thermal stress generated due to temperature distribution, thereby improving the soundness and reliability of the structure. The objective is to provide a fast breeder reactor that can

[Summary of the invention]

The fast breeder reactor according to the present invention includes a reactor vessel containing a coolant and having an opening at the top, a roof slab provided to close the opening, a reactor core provided in the reactor vessel, and A core support mechanism that accommodates and supports the reactor core, a marking cylinder that suspends the core support mechanism that accommodates the core from the roof slab, and a marking cylinder that is provided between the core support mechanism and the reactor vessel to support the core and core support mechanism A horizontal vibration damping member for suppressing vibration in the horizontal direction; an intermediate heat exchanger provided through the roof slab between the reactor vessel and the suspension shell; A partition wall provided in an unrestricted manner with at least two internal parts of the reactor vessel, hanging shell, and intermediate heat exchanger, and a partition wall provided between the core support mechanism and the horizontal vibration damping member in the vertical direction within the reactor vessel. The structure includes a labyrinth rule mechanism that forms a pressure boundary.

That is, above the horizontal damping member (provide a bulkhead in an unrestricted state with at least two of the two reactor vessels, the suspension shell, and the intermediate heat exchanger to form a thermal boundary, and horizontally with the core support mechanism). A pressure boundary is formed by providing a labyrinth seal mechanism between the vibration damping member and the vibration damping member.

Therefore, even if a vertical or horizontal earthquake occurs, it will be absorbed by the labyrinth seal mechanism, so the large load will be absorbed by the bulkhead or horizontal damping member (2). This can be achieved by preventing the generation of high stress without causing any damage to the core.As a result, the displacement of the core and core support mechanism can be tolerated to a certain degree, so it is possible to reduce the amount of material by reducing the weight of the roof slab, for example. Since the reactor vessel, hanging shell, and intermediate heat exchanger are installed in a state where they are tightly constrained, thermal deformation is not restrained, and the pressure boundary formation mechanism (both of which prevent thermal deformation is absorbed, so long-term safety can be improved by reducing the generation of thermal stress.

[Embodiments of the invention]

An embodiment of the present invention will be described with reference to Figures 2 and 3. FIG. 2 is a schematic diagram of a tank-type fast breeder reactor. In the figure, 101 indicates the reactor vessel. This reactor vessel 1
01 (2) contains a coolant 102 (2) to close the upper opening 101A of the reactor vessel 101 (2).
= A roof slab 103 is provided. Reactor vessel 1
A reactor core 104 is installed within the reactor core 104, which is comprised of a plurality of fuel assemblies (not shown), control rods (not shown), and the like. This core 104 is a core support mechanism 105
(Accommodation is supported from the second.

And the core support mechanism 105 that accommodates the core 104
is suspended from the roof slab 103 by a hanging cylinder 07. This hanging body 107 has an open lower 07
A is formed. A core upper mechanism 108 is provided above the core 104, passing through the roof slurry j103 and being supported by the roof slab 103. That is, since the core support mechanism 105 that accommodates the core 104 and the core upper mechanism 108 are both supported by the roof slab 103, even if a vertical seismic motion occurs, for example, the core support mechanism 1' that accommodates the core 104 will not be affected. 05 and the core upper mechanism 10B is extremely small. Therefore, it is possible to prevent a situation in which the core output fluctuates due to a shift in the position of the control rod. In addition, the core support mechanism 105 and the reactor vessel 1
01 and a reactor core 104 and a core support mechanism 10.
5. Horizontal vibration damping member 109 for steadying in the horizontal direction
is provided. A partition wall 110 provided on the inner circumferential side of the reactor vessel 101 above this horizontal vibration damping part paulownia 1θg and a suspension barrel. A partition wall 11 is provided between the horizontal damping member 109 and the horizontal damping member 109. This partition wall 11
1 is installed in a free state from (1) the trunk 107 and the partition wall 110. The partition wall 111 divides the inside of the reactor vessel 101 into upper and lower halves, with the upper part being an upper plenum 112 and the lower part being a lower plenum 113, forming a thermal boundary. (the second is the inlet 114A and the outlet 11
Intermediate heat exchanger with 4B] 14 and circulation pump 11
5 is supported by the roof slab 103 through the roof slab 103 and the partition wall 11. The intermediate heat exchanger 114 is installed free from the partition wall 111. and the horizontal vibration damping member'
JO! ? A labyrinth seal tlNljtl16 is provided between the core support mechanism 105 and the core support mechanism 105.

The labyrinth seal mechanism 116 has a structure in which a plurality of rows of annular grooves 116B are provided on the outer periphery of a hollow cylindrical portion 116A, as shown in FIG. The labyrinth seal mechanism 116 and the core support mechanism 105 are provided in a fitted state to allow for slight eccentric movement in the direction (two directions). By making the gap between the labyrinth seal mechanism 116 C2 small (within a few meters), it is possible to suppress the leakage in the labyrinth seal mechanism 116 C2 to an extent that does not affect the performance and efficiency of the plant. Furthermore, annular leak flow guides 117 and 118 are provided above and below the labyrinth seal mechanism 116, respectively.

The cooling member 10 leaked through the labyrinth seal mechanism 116 due to the leak flow guides 117 and 118.
2 (This is a configuration that reduces the temperature difference between the two and reduces the influence of the temperature difference on the surroundings.

According to the fast breeder reactor having the above configuration, the coolant 102 is used in the core 10.
4 is passed from the bottom to the top and the temperature is raised at that time. The coolant 102 that has flowed into the suspension shell 107 from the core 104 flows out of the dusting shell 107 through the opening 107k of the bowed shell 107 and flows into the intermediate heat exchanger 114 via the inlet 114k. . and intermediate heat exchanger 11
The coolant exchanges heat with the secondary coolant within the reactor core 104, and flows out from the outlet 114B into the lower brenum 113.Then, it is pressurized by the circulation pump 115 and sent again to the lower part of the core 104. Although some leak flow will occur, the gap with the core support mechanism 105 should be made sufficiently small (within a few miles) (from the second point).
It can be suppressed to the extent that it does not affect the performance and efficiency of the plant.

Next, the core 10 due to vertical or horizontal seismic motion
4 and when vertical or horizontal vibrations occur in the core support mechanism 105 (explained in two cases. First, when vertical vibrations occur, C2 is the core support mechanism 10
5 and the horizontal vibration damping member 109 occurs, but the labyrinth seal mechanism 116 does not restrict this relative displacement. And horizontal vibration damping member 10
9 Alternatively, since the bulkhead 111 is provided in a free state from the core support mechanism 105 or the bulkhead 107, a large load is often transmitted. Joint part with body 107 (
2. High stress will not occur. Next (two horizontal seismic motions caused the reactor core 104 and core support mechanism 10 to
5 (2) When horizontal vibration occurs, the vibration is suppressed by the horizontal vibration damping member 109, and at the same time (the nira pilin-sun mechanism 116 is held loosely in the horizontal direction by the horizontal vibration damping member 109). Furthermore, thermal deformation due to differences in temperature distribution between the core support mechanism 105, bow shell 107, horizontal damping member 109, and bulkhead 111 is also absorbed by the labyrinth seal mechanism 116. This is achieved by preventing the generation of thermal stress which is absorbed by the relative displacement of the

That is, a partition wall 111 is provided above the horizontal damping member 109 to form a thermal boundary, and a labyrinth seal mechanism 116 is provided between the horizontal damping member 109 and the core support structure to form a pressure boundary. .

The partition wall 111 is supported by a horizontal damping member 109, and the hanging member 107, partition wall 110, and intermediate heat exchanger 114 are provided in a free state.

Therefore, vertical or horizontal vibrations of the core 104 and the core support mechanism 105 occur due to vertical or horizontal seismic motion [7], but are absorbed by the vertical or horizontal relative displacement of the labyrinth seal mechanism 116 Partition wall 11) and horizontal vibration damping member 10
9 (Secondly, no large load is applied, so stress generation can be prevented and the impact on structural strength can be reduced.

Thereby, the core 104 and the core support mechanism 105
It is possible to tolerate vertical or horizontal displacement of up to a certain large value, for example)
It is also possible to reduce the amount of material by reducing the weight. The partition wall 111 is the suspension body 107.
Since the partition wall 110 and the intermediate heat exchanger 114 are provided in a free state, thermal deformation is not restrained, and the relative displacement of the labyrinth seal mechanism 116 (2) also absorbs thermal deformation, so the thermal deformation is absorbed. The generation of stress can be suppressed, and since leak flow guides 117 and 118 are provided above and below the labyrinth seal mechanism 116, even if the coolant 102 leaks through the labyrinth seal mechanism 116, the temperature will not reach the surroundings. The difference can be reduced and a highly safe fast breeder reactor can be obtained.

〔Effect of the invention〕

The fast breeder reactor according to the present invention includes: a reactor vessel containing a coolant and having an upper part (two openings), a roof slab provided to close the openings, and a reactor core provided in the reactor vessel. A core support mechanism that accommodates and supports this core, a suspension shell that lowers the core support [4%] from the roof slab, and a core and a core that are provided between the core support mechanism and the reactor vessel. Between the horizontal vibration damping member that suppresses the horizontal vibration of the support mechanism, the reactor vessel and the (a) shell (the intermediate heat exchanger provided through the Niluf slab, and the space above the horizontal vibration damping member) a bulkhead provided in an unrestricted manner with at least two of the reactor vessel, the trunk and the intermediate heat exchanger; and the reactor reed provided between the reactor core support mechanism and the horizontal vibration damping member. It has a configuration that includes a roasting mechanism.

That is, a bulkhead is provided above the horizontal damping member in a state where it is not constrained by at least two of the reactor vessel, wall shell, and intermediate heat exchanger, and a thermal boundary is formed between the reactor core support mechanism and the horizontal damping member. A labyrinth seal mechanism is provided in between to form a pressure boundary.

Therefore, even if vertical or horizontal vibration occurs in the core and core support mechanism due to vertical or horizontal seismic motion, it is absorbed by the pressure boundary formation mechanism, so no large load is applied to the bulkhead or horizontal vibration damping members, causing stress. Occurrence can be prevented. Therefore, the displacement of the reactor core and the core support mechanism can be tolerated to a certain extent, so it is possible to reduce the amount of material, such as reducing the weight of the roof slab, for example. Since it is installed in an unrestricted state, thermal deformation is not restricted, and thermal deformation is absorbed by the labyrinth seal mechanism, which reduces the occurrence of thermal stress and improves safety. The effects are great, such as being able to achieve the following.

[Brief explanation of drawings]

Figure 1 is a vertical cross-sectional view of a conventional tank-type fast breeder reactor.
Figures 1 and 3 (not Figure 2) are views showing one embodiment of the present invention, Figure 2 is a longitudinal sectional view of a tank-type fast breeder reactor, and Figure 3 is a partially enlarged view of Figure 2. Two. 10]...Reactor vessel, 103...Roof slab, 1
04... Core, 105... Core support mechanism, 107.
...Hanging body, 109...Horizontal vibration damping member, 111...
Partition wall, 116...Labyrinth seal mechanism.

Claims (2)

[Claims] (1) A reactor vessel that accommodates coolant and has an upper opening, a roof slab that is bifurcated to close the opening, a reactor core installed in the reactor vessel, and a reactor vessel that houses the reactor core. A core support mechanism that supports the core support mechanism, a hinged shell that lowers the core support mechanism that accommodates the core from the roof slab, and a space between the core support mechanism and the reactor vessel (seismic a horizontal vibration damping member for suppressing horizontal shaking during operation; an intermediate heat exchanger provided through the roof slab between the reactor vessel and the wrapping shell; A bulkhead provided in an unrestricted manner with at least two internal parts of the reactor vessel, the hanging shell and the intermediate heat exchanger, and a partition wall provided between the core support mechanism and the horizontal vibration damping member, which is provided between the upper and lower parts of the reactor vessel. A fast breeder reactor characterized by comprising a labyrinth seal mechanism that forms a directional pressure boundary. (2) The above labyrinth seal mechanism is installed on the outer periphery of the horizontal vibration damping member (
2. The fast breeder reactor according to claim 1, wherein the fast breeder reactor is fitted into the inner diameter portion formed so as to be able to move slightly eccentrically in the horizontal direction.