JPH0814634B2 - Distributed reactor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of use] The present invention relates to a distributed reactor in which a small core and a steam generator are modularized as one set or integrated.

[Conventional technology]

In a conventional nuclear reactor, for example, a fast breeder reactor plant, the heat generated in the nuclear reactor has good thermal conductivity, and heat is removed with sodium that is easy to obtain high-temperature steam without pressurization, and high-temperature sodium is piped, pumped, etc. It was transported and the steam generator installed outside the reactor containment facility exchanged heat with water to generate steam and drive the turbine.

The fast breeder reactor "Monju" will be explained as a representative example of this system.

Fig. 4 is a diagram showing the main system of the fast breeder reactor "Monju". In the figure, 1 is a nuclear reactor, 2 is an intermediate heat exchanger, 3 is a primary main circulation pump, 4 is a steam generator, and 5 is 2 Next main circulation pump,
6 is an air cooler, 7 is a turbine, and 8 is a generator.

In the figure, the cooling system is an intermediate heat exchanger 2 in the reactor containment facility, a primary main circulation pump 3, a primary sodium system consisting of pipes and valves, a steam generator 4 outside the reactor containment facility, The secondary main circulation pump 5, a secondary sodium system including pipes and valves, and an auxiliary core cooling system including an air cooler 6 are included.

Sodium in the reactor 1, which has been heated to a high temperature by the heat generated by the fission chain reaction in the reactor, flows out from the outlet nozzle of the reactor 1 and transfers the heat to the secondary sodium system in the intermediate heat exchanger 2. Reactor vessel 9 through main circulation pump 3
Flows in from the nozzle provided at the bottom of the.

Secondary sodium-based sodium flows in from the upper part of the intermediate heat exchanger 2, reverses in the lower plenum, rises in the pipe, absorbs heat from the primary sodium, and flows out from the upper part. Then, it passes through the steam generator 4 and returns to the intermediate heat exchanger 2 through the secondary main circulation pump 5.

In this way, the heat generated in the reactor 1 is taken out of the reactor containment facility via sodium, and the steam generator 4 transfers the heat of sodium to water to generate steam, which drives the turbine 7. Is being generated by the generator 8.

[Problems to be solved by the invention]

As described above, in the conventional fast breeder reactor, the steam generator installed outside the reactor containment facility exchanges the heat generated in the core of the reactor with water through the primary and secondary sodium systems. Since the steam required to drive the turbine was generated, sodium piping, an intermediate heat exchanger, a pump, etc. were required, which was a problem from the viewpoint of high reliability and cost reduction.

In addition, when the reactor power is increased, the core becomes large, and the intrinsic reactivity of the core becomes a positive region, resulting in a decrease in safety.

The present invention is for solving the above-mentioned problems, and a plurality of small-scale core parts having a small-scale core and steam generators are modularized and arranged in a single cooling container, and a core is generated by a natural circulating coolant. Since heat is transferred to the steam generator and taken out of the reactor containment facility, sodium piping, intermediate heat exchangers, pumps, etc. are not required, improving reliability and economic efficiency, and changing the output by changing the number of modules It is an object of the present invention to provide a decentralized nuclear reactor that can deal with such problems and improve safety.

[Means for solving the problem]

Therefore, the present invention is fixed to the bottom surface of the container filled with the coolant, has a flow hole on the side surface, and a small fast reactor having a small core housed in an outer cylinder of the upper end opening narrowed upward, An inner cylinder having a lower end opening fixed to a seal plug of the container and facing the upper part of the small fast reactor and having a flow hole on a side surface, an outer cylinder having a lower end opening enclosing the inner cylinder, and a lower end enclosing the outer cylinder. With an opening protection tube,
A steam generator in which a coil-shaped heat transfer tube is wound around the inner cylinder, a heat transfer tube feed water inlet is provided between the outer cylinder and the protective tube, and a heat transfer tube steam outlet is provided between the inner cylinder and the outer cylinder. In a distributed reactor in which one and more modules are combined into a module and one or more modules are arranged in a cooling container, heat is exchanged by natural circulation of the coolant to generate steam. Characterize.

Further, the present invention includes a small fast reactor having a small-scale core that is housed in a container filled with a coolant and is supported by a support plate at the lower end of an outer cylinder that is narrowed upward, and is fixed to a seal plug of the container. , An inner cylinder having a flow hole on the side surface,
It has an outer cylinder with a lower end opening that surrounds the inner cylinder, and a protective tube with a lower end opening that surrounds the outer cylinder. A coil-shaped heat transfer tube is wound around the inner cylinder, and a heat transfer tube water supply inlet is used as an outer cylinder. A distributed type in which a heat transfer tube vapor outlet is provided between the protective tube and a steam generator provided between an inner cylinder and an outer cylinder to make a module, and one or more modules are arranged in a cooling container. In the nuclear reactor, the outer cylinder supporting the core and the inner cylinder of the steam generator are integrated, and heat is exchanged by natural circulation of the coolant to generate steam.

[Action]

The present invention modularizes a small-scale core portion having a small-scale core and a steam generator provided above the small-scale core portion, and arranges a plurality of them in a cooling container, and heat generated by the core is naturally circulated in the steam generator. It is designed to be used for power generation by exchanging heat with the water in the reactor and being taken out of the reactor containment facility. The naturally circulating coolant transfers the heat generated in the core to the steam generator and takes it out of the reactor containment facility. For sodium piping,
Intermediate heat exchangers and pumps are not required, and reliability and economy are improved, and output changes can be dealt with by increasing or decreasing the number of modules, thus improving safety.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is an explanatory view showing an embodiment of a distributed fast reactor according to the present invention, and FIG. 2 is a vertical sectional view showing an embodiment of a core-steam generator module according to the present invention, in which 20 is sodium. , 21 is the main vessel, 22 is the core / steam generator module, 23
Is a small core, 24 is a steam generator, 25 is a seal plug, 26
Is a small core, 27 is a core vessel, 26 is a core outer tube, 29 is a flow hole, 30 is a communicating tube, 31 is a support plate, 33 is an inner tube, 34 is an outer tube, 35 is a protective tube, 36 is a heat transfer tube, 37 is a water supply inlet, 38 is a steam outlet, and 40 is a fluid flow.

In the distributed fast reactor shown in FIG. 1, a plurality of core / steam generator modules 22 are installed in sodium 20 as a coolant in a main vessel 21 according to the output scale of the reactor.
This module 22 includes a small core portion 23 having a small-scale fast reactor core provided on the bottom plate of the main container 21 and a steam generator 24 provided in a seal plug 25 above the main container 21 so as to face the small core portion 23.
And are modularized as one set.

As shown in FIG. 2, a core vessel containing a small core 26.
27 is a core outer tube 28 fixed to the main vessel 21 and a plurality of support plates 31
Is supported through. The upper portion of the core outer cylinder 28 is narrowed down with an inclined surface, and a plurality of flow holes 29 are provided on the side surface below the small core vessel 27 for circulating sodium 20. Further, a pressure-resistant communication pipe 30 for operating a control rod or the like is provided between the main container 21 and the core container 27.

The steam generator 24 is an inner cylinder 33 fixed to a seal plug 25,
It is composed of an outer cylinder 34, a protection cylinder 35 on the outer side thereof, and a heat transfer tube 36 wound in a coil shape on the outer side of the inner cylinder 33. Also, the inner cylinder 33
A plurality of flow holes 39 are provided above the liquid surface of the sodium 20 for circulation of sodium, and the lower opening faces the opening of the core outer cylinder 28. In addition, the heat transfer tube 36
The upper end of the coil shape passes between the outer cylinder 34 and the protection cylinder 35 to form the water supply inlet 37 outside the seal plug 35, and the other end of the coil shape extends from between the inner cylinder 33 and the outer cylinder 34 to the seal plug 35. The steam outlet 38 is located outside the.

In the core / steam generator module having such a structure, sodium in the core outer cylinder 28, which has been heated to a high temperature by the heat generated by the fission chain reaction in the core 26 of the small core portion 23,
It rises in the core outer cylinder 28, flows in and rises into the inner cylinder 33 of the steam generator 24, and flows out from the flow hole 39 between the inner cylinder 33 and the outer cylinder 34. The water in the heat transfer pipe 36 supplied from the water supply inlet 37 exchanges heat with the high temperature sodium flowing out to become steam, and is taken out of the reactor containment facility through the steam outlet 38. On the other hand, sodium cooled by heat exchange becomes stream 40 and the core outer cylinder
It descends down the slope of 28, flows out of the module, and mixes with sodium 20 in the main container 21. Then, the sodium 2-0 in the main container 21 flows into the periphery of the small core container 27 from the flow hole 29 in the lower portion of the core outer cylinder 28.

In this way, the steam necessary for power generation can be obtained by utilizing the natural circulation of sodium.

FIG. 3 is a longitudinal sectional view showing another embodiment of the core / steam generator module of the present invention. The same numbers as those in FIG. 2 indicate the same contents, 41 is a small core portion, 42 is a core outer cylinder, and 43 Is a communication pipe.

This module consists of the outer core of the small core 41 and the steam generator 24
The inner core and the steam generator are integrated into one structure and fixed to the seal plug 25 at the upper part of the main vessel 21. The heat exchange method and the steam generation method are shown in FIG. It is similar to the one. In the case of this embodiment, the operation of the control rod and the like is performed from the upper part of the main container 21.

〔The invention's effect〕

As described above, according to the present invention, a small core and a steam generator are combined into a module, and a plurality of modules are arranged in one cooling container to use the heat generated by the core by utilizing the natural circulation of the coolant. Heat exchange and take out the generated steam to the outside of the reactor containment facility, sodium pipes, intermediate heat exchangers, pumps, etc. are not required, which improves reliability and economic efficiency and reduces the number of core / steam generator modules. By increasing or decreasing, it is possible to obtain a reactor of arbitrary output. Further, since the core is small, the inherent safety is high, and even if one module fails, the other modules remove heat from the core, further improving safety and reliability. .

[Brief description of drawings]

1 is an explanatory view showing an embodiment of a distributed fast reactor according to the present invention, FIG. 2 is a longitudinal sectional view showing an embodiment of a core / steam generator module according to the present invention, and FIG. 3 is a view according to the present invention. FIG. 4 is a longitudinal sectional view showing another embodiment of the core-steam generator, and FIG. 4 is a view showing a main system of the fast breeder reactor “Monju”. 1 ... Reactor, 2 ... Intermediate heat exchanger, 3 ... Primary main circulation pump, 4 ... Steam generator, 5 ... Secondary main circulation pump,
20 …… Sodium, 21 …… Main container, 22 …… Core / steam generator module, 23 …… Small core, 24 …… Steam generator, 25 …… Seal plug, 26 …… Small core, 28 …… Core outer cylinder, 29, 39 …… Flow hole, 33 …… Inner cylinder, 34 …… Outer cylinder, 35 …… Protection tube, 36 …… Heat transfer tube.

Claims (2)

[Claims] 1. Fixed to the bottom of a container filled with a coolant,
A small fast reactor having a flow hole in the side surface and a small-scale core housed in an outer cylinder with an upper opening narrowed upward, and a small fast reactor fixed to a seal plug of the vessel and arranged to face the upper part of the small fast reactor. A lower end opening inner cylinder having a flow hole on a side surface, a lower end opening outer cylinder surrounding the inner cylinder, and a lower end opening protection tube surrounding the outer cylinder, wherein the inner cylinder has a coiled heat transfer tube And the heat transfer tube feed water inlet is provided between the outer cylinder and the protection tube, and the heat transfer tube steam outlet is modularized by combining a steam generator provided between the inner cylinder and the outer cylinder,
A distributed nuclear reactor in which one or more of the modules are arranged in a cooling vessel, wherein heat is exchanged by natural circulation of a coolant to generate steam. 2. A small fast reactor having a small-scale core supported in a container filled with a coolant and supported by a support plate at the lower end of an outer cylinder narrowed upward, and fixed to a seal plug of the container. An inner cylinder having a flow hole on a side surface, and an outer cylinder having a lower end opening surrounding the inner cylinder,
A heat pipe having a lower end opening that surrounds the outer cylinder, a coiled heat transfer tube is wound around the inner cylinder, and a heat transfer tube feed water inlet is provided between the outer cylinder and the protection tube. Is a distributed reactor in which a steam generator provided between an inner cylinder and an outer cylinder is combined into a module, and one or more modules are arranged in a cooling container. A distributed nuclear reactor characterized in that a cylinder and an inner cylinder of a steam generator are integrated and heat is exchanged by natural circulation of a coolant to generate steam.