JPS62278485A - Nuclear reactor 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] 3. Detailed description of the invention [Industrial application field] The present invention relates to fast breeder reactor vessels, and more particularly to fast breeder reactor vessels.

The present invention relates to a nuclear reactor structure suitable for reducing the construction cost of a nuclear reactor vessel.

[Conventional technology]

A conventional nuclear reactor structure is the one described in Japanese Patent Application Laid-Open No. 60-80788. As shown in Figure 2.

In a fast breeder reactor vessel that has a reactor core and heat exchange equipment, the primary high temperature liquid sodium that has passed through the reactor core 1 is in the hot plenum (26KAl).

It exchanges heat with the secondary im liquid sodium flowing in the helical coil type heat exchanger tubes 24 installed around the entire circumference, is cooled, and collects in the cold plenum 27. This low-temperature primary sodium is pressurized by the mechanical circulation pump 23, passes through the reactor core f25, reaches the high-pressure part in the lower part of the reactor core, and passes through the reactor core 1 again to reach a high temperature.

Furthermore, there is a conventional nuclear reactor structure shown in FIG.

The primary high-temperature liquid (IJ) that has passed through the reactor core passes through the intermediate heat exchanger 28, is pressurized by the electromagnetic pump 29 at the bottom, passes through the in-core piping 25, and enters the high-pressure section at the bottom of the core. Once there, it passes through the core 1 again and reaches a high temperature.

Furthermore, Japanese Patent Application Laid-open No. 57-84391 discloses a nuclear reactor structure in which heat exchanger tubes are of unit type, as shown in FIG.

In all three examples above, a mechanical pump or several intermediate heat exchangers are arranged around the circumference of the reactor core.
The atomic diameter was quite large.

Therefore, no consideration was given to downsizing the reactor vessel, shortening on-site work, and simplifying the structure by reducing the diameter of the reactor.

[Problem that the invention seeks to solve]

The above-mentioned conventional technology does not take into account miniaturization of the reactor vessel, shortening of on-site work, and simplification of the structure from the viewpoint of reducing construction costs, and therefore, the following problems occur frequently.

Since it is not possible to downsize the reactor vessel, the total volume of the vessel is large, which increases construction costs.

Since the container is large, its earthquake resistance is poor, and it is necessary to increase the wall thickness of each part and provide earthquake-resistant ports at various locations, which is undesirable from the viewpoint of generating thermal stress.

Also, when working on-site, it is not possible to transport large pieces all at once.
There was a lot of inefficient on-site work such as the need to assemble the entire product on-site, welding work during on-site installation, assembly work, and scaffolding work.

Furthermore, regarding the structure, internal piping is provided inside the reactor vessel to form a flow path for pumping pressurized liquid sodium into the P core by a circulation pump. The number of piping inside the reactor and the configuration of the seismic support port are determined by the number of pipes inside the reactor and the number of electromagnetic pumps located at the bottom of the intermediate heat exchanger, making the inside of the reactor vessel complex.

An object of the present invention is to provide a nuclear reactor structure that can solve these problems and reduce construction costs.

[Means for solving problems]

The above objectives were achieved in the following manner.

Namely.

(υ - Several annual three"6 induction pump type electromagnetic pumps were installed at the bottom of the core as circulation pumps in the downstream liquid sodium flow path. These electromagnetic pumps were installed in the cold plenum at the bottom of the sb and f core. A high pressure plenum is formed at the

C) Instead of an intermediate heat exchanger, only heat transfer tubes were arranged on the circumference in parallel with the P core so that the primary mg sodium flowed through the heat transfer tubes.

(3) A structure was adopted in which the secondary 11111 liquid sodium passed through the outer circumference of the heat transfer tube, and a cold plenum containing the low-temperature secondary 11g liquid sodium was formed in the outer shell of the reactor vessel.

[Effect]

Several annulus linear induction pump type electromagnetic pumps are installed at the bottom of the reactor core.

A high-pressure plenum is formed at the bottom of the f-core in order to ensure the necessary pressure for next-side liquid sodium to pass through the core, and to properly cool the IJ-umn reactor core. Unlike a type circulation pump or an electromagnetic pump at the bottom of an intermediate heat exchanger, the space required in parallel with the reactor core is no longer required, and the core diameter of the reactor vessel can be reduced.

Also, compared to the conventional atomic f-container with several intermediate heat exchangers arranged, the intermediate heat exchangers are spaced apart from each other in order to allow the high-temperature liquid sodium on the downstream side to flow through the heat transfer tubes. Unlike the configuration in which the heat exchanger tubes are arranged on the circumference, extra space is not required, and the area occupied by the heat exchanger tubes can be reduced.

Therefore, the area occupied by the space corresponding to the conventional mechanical circulation pump and intermediate heat exchanger becomes smaller, resulting in a smaller furnace diameter.

Since the reactor diameter can be made smaller, the reactor vessel can be assembled in the factory instead of being assembled on-site, greatly increasing work efficiency. In addition, on-site welding and assembly work is eliminated, the on-site work process is shortened, and the overall process can be clearly understood.

Piping inside the reactor becomes unnecessary, and the structure inside the atomic f-vessel becomes simple.

〔Example〕

An embodiment of the present invention will be described below with reference to FIG.

The primary liquid in the reactor vessel is pressurized by passing through the electromagnetic pump 2 from the lower plenum 12, which serves as a cold plenum, and reaches the high-pressure plenum 21. pass through. When passing through this reactor core 1, the generated heat t of the -order system liquid sodium riF core 1
``Take it away and make it high temperature.''

It flows into the upper plenum 11, which is the upper hot plenum. This high-temperature liquid sodium flows down from the upper tube plate 4 into the heat transfer tube 6, passes through the lower tube plate 5, and reaches the F section plenum 12 located at the lower part.

After exchanging heat with the secondary steam generator, the secondary system liquid sodium becomes low temperature and is transferred to the reactor vessel outer shell 15.
It flows into the side wall space 13 on the entire circumference of the cold plenum between the inner shell 14 and the inner shell 14.

In the lower part of this side wall space 13, there is a secondary system inlet nozzle 7, which was located in the inner shell 141111, and through this artificial nozzle 7, the secondary system liquid sodium rises in the area outside the heat exchanger tube 6, and flows into the inner shell. It passes through the secondary system outlet nozzles 8 provided at several locations in the upper part of the shell 14 and flows into the high-temperature side wall space 20 where it simmers in the hot plenum located in the entire circumferential area inside the soil part of the side wall space 13.
It passes through the outlet pipe 10' and returns to the secondary system.

The reactor vessel outer shell 15 is supported on the building by an upper flange 17, and the equipment and members within the inner shell 14 are attached to the outer shell 15 in the gas layer above the reactor vessel. atom f
A shield plug 18 is installed at the top of the container, and the fuel is put in and taken out in the center.

A reactor upper mechanism 19 having a control rod drive mechanism is installed.

The liquid surface of the primary liquid sodium is in contact with the inner body plate of the high temperature side wall space 20. A heat insulating material 22 is installed between the outer shell plate of the high temperature side wall space 20 and the inner shell 14 of the reactor vessel. This inner trunk 14+'! , is attached to the outer shell 15 at the upper part with a gas layer. Therefore, the outer shell 15 of the reactor vessel always serves as a cold plenum in a low temperature region. Furthermore, although the upper tube plate 4 and the inner body plate of the high temperature side wall space 20 become high temperature,
- There is no occurrence of thermal stress at high temperatures in both the secondary liquid sodium and the secondary liquid sodium. The lower tube plate 5 is at a low temperature like the secondary system liquid sodium at the secondary system inlet nozzle 7, and no thermal stress is generated.

The reactor core 1 and electromagnetic pump 2 are held by an inner shroud 3, which is fixed to an inner shell 14 by an upper tube sheet 4 and a lower tube sheet 5.

The structure of the 1-magnetic pump 2 will be explained with reference to FIG.

The annular linear induction pump S''i is equipped with 61 points of annular linear induction pumps in one row, and the capacity is increased by increasing the number of pumps.・Flow velocity is obtained by the primary sodium body passing through the gap between g31 and the cylindrical inner core 30. On the outside of the inner tube, there are several rows of block-shaped laminated cores 33 in the axial direction. Once installed, a coil 32 is wound circumferentially within the coil 32. By manipulating the current within this coil, the magnetic field within the laminated iron core 33 is adjusted.

Furthermore, the circumferential direction within the printed version sodium! 11 a'fc
adjustment and, as a result, the streamwise flow rate of the sodium hydroxide can be varied. The inner core 30 is fixed to the inner tube by an inner core support beam 34. The inside of this electromagnetic pump includes an inner pipe 31 and an electromagnetic pump upper plate 36. The electromagnetic pump outer body 35 and the electromagnetic pump lower plate 37 form a sealed structure. Since the electromagnetic pump is installed in the cold plenum, the operating temperature is 300C to 400C.
Considering the coil's heat resistance temperature of approximately 700C, this is sufficiently permissible.

FIG. 6 shows the detailed structure of the atomic f container. As shown in this structure, the upper part of the inner shroud 3 is attached to an upper tube plate 4, and a large number of heat transfer tubes 6 through which the primary liquid sodium passes are attached to the upper tube plate 4. Further, the upper tube plate is attached to the inner shell plate of the high temperature side wall space 20 filled with secondary liquid sodium, and is connected to the inner shell 14 through a gas layer.
5 in a Y-shape. The inside of the outer shell 15 is a low-temperature side wall space 13 filled with secondary liquid.
A heat insulating material 22 is filled between the holes to prevent the heat from flowing out of the high temperature secondary liquid. Since the inside of the outer shell is kept in a low-temperature region, the outer shell of the reactor vessel can be designed to have a low temperature, making it easy to ensure structural integrity. Further, although a high temperature primary liquid sodium region and a high temperature secondary liquid sodium region are formed with the upper tube plate 4 as a boundary, thermal stress hardly occurs because the two liquids have a higher weight resistance due to the difference in temperature.

According to these examples, several annulus linear induction pump type electromagnetic pumps are arranged as circulation pumps, and heat transfer tubes are arranged in parallel with the reactor core as heat exchange equipment, so it is not necessary to use circulation pumps as in the past. There is no need to place it in parallel with the reactor core, and it can be brought to the bottom of the reactor core 1. This results in a reduction in the diameter of the furnace. Also,
In-furnace piping to form a circulation loop becomes unnecessary. −
The secondary liquid sodium heat exchanger requires only heat transfer tubes, and the volume can be reduced at the same time. Furthermore, since the outer shell of the atomic f-container is in a low-temperature region, the integrity of the container increases.

〔Effect of the invention〕

According to the present invention, since the reactor vessel can be made smaller by eliminating piping inside the reactor, on-site assembly is not necessary, and integrated production can be performed at a factory, thereby reducing the number of on-site assembly man-hours and the amount of materials. Construction costs can now be reduced.

[Brief Description of the Drawings] Figure 1 is a cross-sectional view of a nuclear reactor vessel according to an embodiment of the present invention;
4 are schematic diagrams of conventional reactor vessels, FIG. 5 is a perspective view of the electromagnetic pump used in the present invention, and FIG. 6 is a structural assembly of the heat exchanger tube holder of the present invention. .1《1 Fulham 23, Toshii %Eip'>7' 24 Helica 1 and Koi 1shi & (Ebebe Shoken 25-f, f'R Shinkokan 2ro, Bozutobushi Tsum 27, Ko 1shi Dobushisumu 3 Mouth 25. Ugly piping 2g, frli 1% flame protection answer 2 Zoro heavy weight hon 2゜ 5th b 3o, inner Buddha 411 ji 31 round arm 3'' 1.4 tj Ii control posture J reaction certain Otsu Roa 2 ti'tji, material

Claims (1)

[Claims] 1. In a fast breeder reactor reactor vessel having a reactor core and heat exchange equipment inside, a heat transfer tube is arranged around the core, through which the primary sodium flows down, and the secondary sodium A nuclear reactor structure in which the primary sodium passes through an electromagnetic pump located at the lower part of the reactor core and forms a route back to the reactor core. 2. A nuclear reactor structure according to claim 1, wherein the reactor vessel wall is a double wall and forms a cold plenum as an inflow route for the secondary sodium system.