JPS5961797A - Fast breeder - 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 invention] The present invention relates to 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 suspended from the roof slab 'f3 by a suspension shell 7. This suspension body 7 has an open lower lower A formed therein. The core 4
A core upper mechanism 8 is provided on the ground by passing through the roof slab 3 and being supported by the roof slab 3. In other words, since the core support mechanism 5 housing the core 4 and the core upper mechanism 8 are both supported by the roof slab 3, even if a vertical seismic motion occurs, for example, the core support mechanism housing the core 4 will not work. 5 and the core upper mechanism 8 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. A horizontal restraining member 9 is provided between the core support mechanism 5 and the reactor vessel 1 to prevent the core 4 and the core support mechanism 5 from swaying in the horizontal direction. A partition wall 11 is provided between a partition wall 10 provided on the inner peripheral side of the reactor vessel 1 above the horizontal steady rest member 9 and the suspension shell 7 . The partition wall 11 divides the interior of the reactor vessel 1 into upper and lower halves, with the upper part serving as an upper solenum 12 and the lower part serving as a lower plenum 13. Between the suspension shell 7 and the reactor vessel 1, an intermediate heat exchanger 14 having an inlet J4A and an outlet 14B and a circulation pump 15 penetrate the roof slab 3 and the partition wall 1, and the roof slab 3 It is supported and installed. A sealing mechanism 16 is provided between the intermediate heat exchanger 14 and the partition wall 11 to seal the upper plenum 12 side and the lower plenum 13 side. The sealing mechanism 16 is connected to the partition wall 1 as shown in FIG.
1 and intermediate heat exchanger 14, respectively, and a bellows 19 is provided between the thin plates 17 and 18.

According to the fast breeder reactor having the above configuration, the coolant 2 flows through the reactor core 4 from below to above, and is heated at this time.

The coolant 2' flowing from the core 4 into the suspension shell 7
flows out of the hanging cylinder 7 through the open lower A of the hanging cylinder 7, and flows into the intermediate heat exchanger 14 through the inlet 14k. Then, it exchanges heat with the secondary coolant in the intermediate heat exchanger 14, and flows out into the lower lunum 13 from the outlet 14B. Then, it is pressurized by the circulation pump 15 and sent to the lower part of the reactor core 4 again.

[Problems with background technology]

According to the above configuration, the partition wall 11 includes the partition wall 10 and the hanging cylinder 7.
The reactor vessel 1 is provided in a completely connected state and forms 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 reactor core 4 and the core support mechanism 5 vibrate in the vertical or horizontal direction. At that time, there is a possibility that high stress may be generated at the joints between the partition wall 11, the partition wall 1°, and the hanging body 7. Furthermore, due to the occurrence of severe temperature distribution, thermal stress may occur particularly near the joint with the hanging cylinder 7.

[Purpose of the invention]

The purpose of the present invention is to reduce the stress generated in the bulkhead during vertical and horizontal displacement of the core and core support mechanism, and to reduce the thermal stress generated due to temperature distribution, thereby improving safety. The purpose is to provide fast breeder reactors.

[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 m 474 that accommodates and supports the reactor core, a suspension shell that suspends the core support mechanism housing the core from the roof slag, and a core and core support mechanism provided between the core support mechanism and the reactor vessel. a horizontal steady rest member for providing steady rest in the horizontal direction; an intermediate heat exchanger 32' 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 of the reactor vessel, the hanging shell and the intermediate heat converter, and a partition wall provided between the reactor core support mechanism and the horizontal steady rest member, and provided between the reactor vessel, the suspended shell and the intermediate heat converter, and the upper and lower parts of the reactor vessel. This configuration includes a pressure boundary forming mechanism that forms a pressure boundary in the direction.

In other words, the reactor vessel is placed above the horizontal steady rest member.

A bulkhead is provided in an unconstrained state with at least two of the hanging shells and intermediate heat exchangers to form a thermal boundary, and a pressure boundary forming mechanism is provided between the core support mechanism and the horizontal steady rest member. This configuration forms 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 will be absorbed by the pressure boundary forming mechanism, so it will not be necessary to use the bulkhead or horizontal photographic stop member. A large load is not applied to the structure, and high stress can be prevented from occurring. As a result, the displacement of the core and the core support mechanism can be tolerated to a certain degree, so that it is possible to reduce the amount of material, such as reducing the weight of the roof slab, for example. Since the bulkhead is provided in at least two of the interiors of the reactor vessel, suspension shell, and intermediate heat exchanger in an unrestricted state, it does not restrict thermal deformation.
Further, since thermal deformation is also absorbed by the pressure boundary forming mechanism, the occurrence of thermal stress can be reduced and safety can be improved.

[Embodiments of the invention]

An embodiment of the present invention will be described with reference to FIGS. 2 and 3. FIG. 2 is a schematic diagram of a tank-type fast breeder reactor. In the figure, 101 indicates a reactor vessel. This reactor vessel 10
1 contains a coolant 102. A roof slab 103 is provided to close the upper opening 101k of the reactor vessel 101. Inside the reactor vessel 101, a reactor core 1θ4 is installed, which is composed of a plurality of fuel assemblies (not shown), control rods (not shown), etc.
1 This core 1θ4 is accommodated and supported by a core support mechanism 105.

The core support mechanism 105 containing the reactor core 104 is suspended from the roof slab 103 by a suspension shell 107. This suspension barrel 107 has an opening 107A formed therein. Above the core 104 is a core upper mechanism 1.
08 is provided passing through the roof slab 103 and being supported by the roof slab 103. That is, since both the core support structure 105 that accommodates the core 104 and the core upper mechanism 108 are supported by the roof slab 103, even if a vertical seismic motion occurs, the core support mechanism 105 that accommodates the core 104 and the core upper mechanism 108 are both supported by the roof slab 103. The relative displacement with the upper core mechanism 108 is extremely small. Therefore, it is possible to prevent a situation in which the core output fluctuates due to misalignment of the control rods. Further, between the core support mechanism 105 and the reactor vessel 101, there is a core 10.
4 and a horizontal steadying member 109 for stabilizing the core support mechanism 105 in the horizontal direction. A partition wall 111 is supported by the horizontal steady rest member 109 and is provided between a partition wall 110 provided on the inner peripheral side of the reactor vessel 101 above the horizontal steady rest member 109 and the suspension shell 107. This partition wall 111 is connected to the hanging cylinder 107. The partition is 1
10 is installed in a free state. The partition wall 111 divides the interior of the reactor vessel 101 into upper and lower halves, with an upper plenum 112 at the top and a lower plenum 113 at the bottom, forming a thermal boundary. Between the suspension shell 107 and the reactor vessel 101, an inlet 114A and an outlet 1 are provided.
Intermediate heat exchanger 114 and circulation pump 1 with 14B
15 is provided to penetrate the roof slab 103 and the partition wall 111 and to be supported by the roof slab 103. The intermediate heat exchanger 114 is installed free from the partition wall 111. and the horizontal steady rest member 10
9 and the core support mechanism 105 is provided with a manometer knoll mechanism 116 as a pressure boundary forming mechanism.

As shown in FIG. 3, this manometer seal mechanism 116 is provided between an annular member 117 provided on the outer periphery of the core support mechanism 105 and whose upper end is in contact with the core support mechanism 105, and an annular member 117 and the core support mechanism 105. It consists of an annular member 118 that stands up from a horizontal photographic stop member 109 located at the position , and the inside thereof is filled with argon gas 119 . The pressure difference between the cylindrical portion/high pressure upper plenum 112 side and the lower temperature/low pressure lower plenum I J 31+114 is balanced and sealed by the coolant water head (6).

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 suspended shell 1θ7 from the core 104
flows out of the hanging cylinder 107 through the opening 107A of the hanging cylinder 1θ7, and flows into the intermediate heat exchanger 114 through the inlet 114A. Then, heat is exchanged with the secondary cooling in the intermediate heat exchanger 114, and from the outlet 114B to the lower plenum 113.
Then, it is pressurized by the circulation pump 115 and sent to the lower part of the reactor core 104 again.

Next, the core 10 due to vertical or horizontal seismic motion
4 and the case where vertical or horizontal vibration of the core support mechanism 105 occurs will be explained. First, when vibration occurs in the vertical direction, the annular part control 7 provided in the core support mechanism 105 vibrates in the vertical direction together with the core support @ structure 105. This is absorbed by the relative vertical displacement of the manometer seal mechanism 116, which is made up of an annular member 118 and an annular member 118. Since the horizontal photographic stopper member 109 or the bulkhead 11) is provided in a free state from the core support mechanism 105 or the suspension shell 107, a large load is not transmitted to it, and it is not necessary to use the bulkhead as in the past. There is no possibility that a high stress will be generated at the joint between the hanging cylinder 107 and the hanging cylinder 111. Next, when horizontal vibration occurs in the P core 104 and the core support mechanism 105 due to horizontal ground movement, the vibration is suppressed by the horizontal steady rest part side 109, and at the same time the vertical vibration is suppressed. As in the case of vibration, the displacement is absorbed by the relative horizontal displacement of the manometer sealing machine.

In addition, the core support machine Ml 05 and the suspension shell 107. Thermal deformation caused by the difference in temperature distribution between the horizontal steady rest member 109 and the distance Vt 111'i and rl can also be absorbed by the relative displacement of the manometer seal mechanism 116 to prevent generation of thermal stress.

That is, a partition wall 111 is provided above the horizontal steady rest member 109 to form a thermal boundary, and a manometer seal mechanism 11 is provided between the horizontal steady rest member 109 and the core support mechanism 105.
6 forms a pressure boundary. The partition wall Jll is supported by the horizontal steady rest member 109, and the suspension body 1
07, the partition wall 110 and the intermediate heat exchanger 114 are provided in a free state.

Therefore, even if vertical or horizontal vibration occurs in the core 104 and the core support mechanism 105 due to vertical or horizontal seismic motion, the relative displacement of the manometer seal mechanism 116 in the vertical or horizontal direction will not occur. The bulkhead 111 and the horizontal steady rest member 109
No large load is applied to the reactor core 104 and the core support mechanism 105, thereby reducing the vertical or horizontal displacement of the reactor core 104 and core support mechanism 105 to a somewhat large value. For example, it is possible to reduce the amount of material by reducing the weight of the roof slab 1o3. The partition wall 11 is the hanging cylinder 1o2° partition wall 11.
0 and intermediate heat exchanger 1 and 14 are provided in a free state, thermal deformation is not restricted, and thermal deformation is also absorbed by the relative displacement of the manometer seal mechanism 116. Next, as shown in FIG. Another embodiment will be described with reference to the following.

That is, the horizontal stabilization member 109 and the core support mechanism 105
In this configuration, a double manometer seal mechanism 120 is provided as a pressure boundary forming mechanism between the two. In this case, it is possible to perform sealing with a higher pressure difference than with the manometer sealing machine M1xe of the above embodiment, and it is possible to seal the core 1o4. When vertical or horizontal vibration occurs in the core support mechanism 105, the partition wall 11 and the horizontal photographic prevention member i absorb the displacement.
It has the same effects as the manometer seal mechanism 116 of the previous embodiment, such as reducing the stress generated in the og or absorbing thermal deformation to suppress the generation of thermal stress.

〔Effect of the invention〕

The heavy-speed breeder reactor according to the present invention includes a reactor vessel that houses a coolant and has an opening at the top, and a reactor vessel that contains a coolant and has an opening at the top, and a closed X? 4. A roof slab provided in such a manner that the reactor core is provided within the reactor vessel, and a core support mechanism that accommodates and supports the reactor core.
A suspension V) for suspending the core support mechanism containing the reactor core from the roof slab;
A horizontal steady rest member provided in the horizontal direction of the structure, an intermediate heat exchanger provided through the roof slab between the reactor vessel and the suspension shell, and a horizontal steady rest member provided above the horizontal steady rest member. a partition wall provided in an unrestricted state with at least two internal parts of the reactor vessel, the hanging shell, and the intermediate heat exchanger;
The structure includes a pressure boundary forming mechanism that is provided between the reactor core support mechanism and the horizontal camera stop member and forms a pressure boundary in the vertical direction inside the reactor vessel. At least two of the vessel, suspended shell, and intermediate heat exchanger are provided with a bulkhead in an unrestrained state to form a thermal boundary, and a general pressure boundary formation mechanism is provided between the core support 0144 and the horizontal steady rest member. This is a configuration in which a pressure boundary is formed by

Therefore, even if vertical or horizontal vibration occurs in the core and the core support machine 41''l due to vertical or horizontal force direction seismic motion, it will be absorbed by the pressure boundary formation mechanism, so it can be used as a bulkhead or as a horizontal steady rest member. As a result, the displacement of the core and core support mechanism can be allowed to be large to some extent, so it is possible to reduce the amount of material by, for example, making the roof slab lighter.
can be done. and lh L5f, is the reactor vessel,
Since the suspension shell and the intermediate heat exchanger are installed in an unrestricted state, thermal deformation is not restrained, and thermal deformation is absorbed by the pressure boundary formation mechanism, so thermal stress is reduced. Its effects on humans include being able to reduce the occurrence of accidents and improve safety.

[Brief explanation of drawings]

Figure 1 is a vertical cross-sectional view of a conventional tank-type fast breeder reactor.
Figures 2 and 3 are diagrams showing one embodiment of the present invention.
The figure is a longitudinal sectional view of a tank-type fast breeder reactor, FIG. 3 is a partially enlarged view of FIG. 2, and FIG. 4 is a sectional view showing another embodiment. 101... Reactor vessel, 103... Roof slab,
104... Core, 105... Core support mechanism, 107
... Hanging 9 trunks, 109 ... Horizontal steady rest, 111
...Partition wall, 116... Manometer seal mechanism (pressure boundary formation mechanism). Applicant's agent Patent attorney Takehiko Suzue 517

Claims (2)

[Claims] (1) A reactor vessel that accommodates coolant and has an opening at the top, a roof slab provided to close the opening, a reactor core provided in the reactor vessel, and a reactor vessel that accommodates and supports the core. A core support mechanism, a suspension shell that suspends the core support mechanism containing the core from the roof slab, and a suspension shell provided between the core support mechanism and the reactor vessel to prevent horizontal swing of the core and the core support mechanism. A horizontal steady rest member for stopping, an intermediate heat exchanger provided through the roof slab between the reactor vessel and the suspension shell, and an intermediate heat exchanger provided above the horizontal steady rest member for the reactor vessel and the suspension shell. A partition wall provided in an unconstrained manner with at least two of the shell and intermediate heat exchanger, and a partition wall provided between the core support mechanism and the horizontal photographic stopper, which defines a pressure boundary in the vertical direction within the reactor vessel. A fast breeder reactor characterized by comprising a pressure boundary forming mechanism. (2) The fast breeder reactor according to claim 1, wherein the pressure boundary forming mechanism is comprised of a manometer seal mechanism.