JPH04110694A - Fast breeder reactor - Google Patents

Abstract

PURPOSE:To intend improvement of maintainability by providing an electro-magnetic pump integrally underneath an intermediate heat exchanger and by sending primary coolant inside a primary cold pool from a pressure plenum into a reactor core inside. CONSTITUTION:An electro-magnetic pump 4 is integrally provided underneath an intermediate heat exchanger 3 and primary coolant that is heat-exchanged by the intermediate heat exchanger 3, is made to be discharged from a discharging outlet 5 to a lower part of a primary container 1. With this sort of constitution, the primary coolant in a primary cold pool 7 can be transferred into a reactor core 2 from a pressure plenum 9 formed at a lower part of the reactor core 2, by the electro-magnetic pump 4 which is integrally provided underneath the intermediate heat exchanger 3, and therefore there is no need to arrange primary coolant circulation pumps around the reactor core 2 and also a ring shaped space part between the reactor core 2 and the primary container 1, can be cut down circumferentially. In this way, the primary container can be down-sized and therewith more compactly structured fast breeder reactor can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a fast breeder reactor, and particularly to a fast breeder reactor in which the main vessel has a double vessel structure.

(Prior Art) Fast breeder reactors that use liquid metal sodium as a coolant are broadly classified into tank type and loop type depending on the type of reactor. Among these, tank-type fast breeder reactors have an intermediate heat exchanger, a primary coolant circulation pump, etc. installed in the reactor vessel, which is the main vessel, and the primary coolant contained in the reactor vessel is transferred to the intermediate heat exchanger. It is designed to exchange heat with the secondary coolant and absorb the nuclear reaction heat in the reactor core.

Tank-type fast breeder reactors configured in this way do not require primary cooling system piping unlike loop-type fast breeder reactors, so they have advantages such as no sodium leakage due to piping breakage. Since the secondary coolant circulation pump etc. are installed outside the reactor vessel, secondary cooling system piping is required to connect the steam generator and the secondary coolant circulation pump to the intermediate heat exchanger. However, there was a problem in that space was required to install these secondary cooling system devices, and the overall plant configuration became large-scale.

Therefore, in order to solve this problem, Figure 3 (Pro roeof
International S
ynposium onL M F B RD ev
elopment P, 4-5-1 to 4-5-17N
ov, 1954. A fast breeder reactor with a double vessel structure as shown in Tokyo) is being considered. In the figure, reference numeral 31 denotes a primary vessel containing a primary coolant, and a reactor core 32 is installed inside this primary vessel 31, and an intermediate heat exchanger 3B and a secondary coolant circulation pump 34 are connected to the reactor core. They are arranged alternately around 32. A control rod drive mechanism 35 is provided above the reactor core 32, and the control rod drive mechanism 35 inserts the control rods 36 into the reactor core 32 and withdraws the control rods 36 from the reactor core 32 to control the nuclear reactivity of the reactor core 32. It's in control.

The inside of the primary vessel 31 is divided into a cold pool 38 and a hot pool 39 by a partition wall 37, and the primary coolant (low-temperature sodium) in the cold pool 38 is transferred to the lower part of the reactor core 32 by a primary coolant circulation pump 34. The air flows into the core 32 from a pressure plenum 40 formed in the reactor core 32 . The primary coolant that has flowed into the reactor core 32 is heated to a high temperature by the nuclear reaction heat of the reactor core 32, and flows out from the upper part of the reactor core 32 into a hot pool 39.

On the other hand, the primary coolant (high temperature sodium) in the hot pool 39 flows into the intermediate heat exchanger 33 to exchange heat with the secondary coolant. The primary coolant that has exchanged heat with the secondary coolant turns into low-temperature sodium and flows out into the cold pool 38, where it is sent into the reactor core 32 again from the pressure plenum 40 by the primary coolant circulation pump 34. There is.

Further, the primary container 31 is contained inside a secondary container 41, and a secondary coolant is accommodated in the secondary container 41, as well as a steam generator 42 and a secondary coolant circulation pump 43. are arranged around the primary container 31. A roof slab 44 is provided above the secondary container 41, and this roof slab 44 allows the primary containers 31 and 2
The upper opening of the next container 41 is hermetically closed.

The intermediate heat exchanger 33 has secondary sodium piping 45.46
via a steam generator 42 and a secondary coolant circulation pump 43
The secondary coolant that has exchanged heat with the primary coolant in the intermediate heat exchanger 33 is introduced into the steam generator 42 through the secondary sodium pipe 45, and the steam generator 42 exchanges water and heat. They are replaced to generate superheated steam to drive the turbine.

The secondary coolant that has undergone heat exchange in the steam generator 42 is caused to flow into the intermediate heat exchanger 33 again through a secondary sodium pipe 46 by a secondary coolant circulation pump 43.

(Problems to be Solved by the Invention) In the fast breeder reactor configured as described above, the primary container 31 containing the primary coolant is enclosed inside the secondary container 41, and the secondary container 41 contains two The primary container 31 accommodates the secondary coolant and also contains the steam generator 42 and the secondary coolant circulation pump 43.
Since the structure is arranged around the reactor vessel, there is no need for space for installing secondary cooling system equipment outside the reactor vessel, and the entire plant can be made more compact. However, the conventional fast breeder reactor described above has a steam generator 4
Since the secondary coolant circulation pump 43 was connected to the intermediate heat exchanger 33 by the secondary sodium piping 45, 46, the piping structure in the upper part of the furnace was complicated, resulting in poor maintainability. Furthermore, in the past, the intermediate heat exchanger 33 and the primary coolant circulation pump 34 were disposed around the reactor core 32, so there was a limit to the miniaturization of the primary vessel 1.

The present invention has been made in view of these points, and aims to improve maintainability by simplifying the piping structure in the upper part of the reactor, and also to eliminate restrictions on the arrangement of primary cooling system equipment installed in the primary vessel. It is an object of the present invention to provide a fast breeder reactor that can reduce the size of the primary vessel.

[Structure of the Invention] (Means for Solving the Problems) In order to achieve the above object, the present invention includes a primary container containing a primary coolant, and a secondary coolant contained in the primary container. A secondary vessel containing the secondary vessel, a roof slab that closes the upper opening of the secondary vessel and the primary vessel, a reactor core installed in the primary vessel, and a control rod inserted into the core and the a control rod drive mechanism that extracts control rods from the core; a first partition wall that divides the inside of the primary vessel into a primary hot pool and a primary cold pool; an intermediate heat exchanger for exchanging heat between the secondary coolant and the secondary coolant; a pressure plenum formed at the lower part of the core; an electromagnetic pump that causes coolant to flow into the reactor core from the pressure plenum; a second partition wall that divides the inside of the secondary vessel into a secondary hot pool and a secondary cold pool; a steam generator that generates steam by exchanging heat with water of a secondary coolant that has undergone heat exchange with the primary coolant in a heat exchanger; and a steam generator that is installed in the secondary container and flows from the steam generator to a secondary cold pool. a secondary coolant circulation pump that introduces the secondary coolant that has flowed out into the intermediate heat exchanger via a secondary coolant inlet pipe;
A secondary coolant outlet pipe is provided coaxially outside the secondary coolant inlet pipe and allows the secondary coolant that has exchanged heat with the primary coolant in the intermediate heat exchanger to flow out into the secondary hot pool. It is something.

(Function) In the present invention, an electromagnetic pump is integrally provided at the lower part of the intermediate heat exchanger, and this electromagnetic pump is configured to feed the primary coolant in the primary cold pool from the pressure plenum into the reactor core. Since there is no need to arrange a primary coolant circulation pump around the primary container, the primary container can be made smaller.

In addition, the inside of the secondary container is divided into a secondary hot pool and a secondary cold pool by a second partition, and secondary coolant inlet piping that introduces the secondary coolant in the secondary cold pool to the intermediate heat exchanger. The piping structure in the upper part of the furnace can be simplified by coaxially providing the secondary coolant outlet piping that leads the secondary coolant that has exchanged heat with the primary coolant in the intermediate heat exchanger to the secondary hot pool on the outside of the furnace. Maintainability can be improved.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

1 and 2 show one embodiment of the present invention, and FIG. 1 is a vertical cross-sectional view showing a schematic configuration of a fast breeder reactor according to the present invention,
FIG. 2 is a plan view of FIG. 1.

1 and 2, reference numeral 1 denotes a primary vessel containing a primary coolant, and inside this primary vessel 1, a reactor core 2 is installed, and an intermediate heat exchanger 3 or the surrounding area of the reactor core 2 is installed. It is located in At the bottom of this intermediate heat exchanger 3 is an electromagnetic pump 4.
are integrally provided, and the primary coolant that has undergone heat exchange with the intermediate heat exchanger 3 is discharged from a discharge 805 to the lower part of the primary container 1 by the electromagnetic pump 4.

Further, the inside of the primary container 1 is divided into a primary cold pool 7 and a primary hot pool 8 by a first partition 6,
The primary coolant (low-temperature sodium) in the primary cold pool 7 flows into the core 2 from a pressure plenum 9 formed at the bottom of the core 2 by the discharge pressure of the electromagnetic pump 4 described above. The primary coolant flowing into the reactor core 2 is heated to a high temperature by the nuclear reaction heat of the reactor core 2, and flows out from the upper part of the reactor core 2 into the primary hot pool 8.

On the other hand, the primary coolant (high temperature sodium) in the primary hot pool 8 flows into the intermediate heat exchanger 3 from the inlet 10 and flows into the intermediate heat exchanger 3.
It is designed to exchange heat with the next coolant. The primary coolant that has exchanged heat with the secondary coolant turns into low-temperature sodium and flows out into the primary cold pool 7, and as described above, is sent into the reactor core 2 again from the pressure plenum 9 by the discharge pressure of the electromagnetic pump 4. It looks like this. A control rod drive mechanism (not shown) is provided above the reactor core 2, and this control rod drive mechanism inserts the control rods (not shown) into the reactor core 2 and pulls the control rods out of the reactor core 2. It controls the nuclear reactivity of the reactor core 2.

Further, the primary container 1 is contained inside a secondary container 11, and a secondary coolant is accommodated in the secondary container 11, as well as a steam generator 12 and a secondary coolant circulation pump 13. are arranged around the primary container 1. and,
The upper part of the secondary container 11 is provided with a roof slab 14,
The roof slab 14 hermetically closes the upper openings of the primary container 1 and the secondary container 11.

Further, the inside of the secondary container 11 is divided into a secondary cold pool 16 and a secondary hot pool 17 by a second partition 15, and the secondary coolant (low temperature sodium) in the secondary cold pool 16 is supplied to the suction port 18. The coolant is sucked into the secondary coolant circulation pump 1B, and is introduced into the intermediate heat exchanger 3 through the secondary coolant inlet pipe 19. The secondary coolant that has undergone heat exchange in the intermediate heat exchanger 3 is then transferred to a secondary coolant ratio pipe 2 coaxially provided outside the secondary coolant inlet pipe 19.
0 and flows out into the secondary hot pool 17.

On the other hand, the secondary coolant (high temperature sodium) in the secondary hot pool 17 flows into the steam generator 12 from the inlet 21,
This steam generator 12 exchanges heat with water to generate superheated steam for driving a turbine.

The secondary coolant that has undergone heat exchange in the steam generator 12 flows into the secondary cold pool 16 and is sucked into the secondary coolant circulation pump 13 again through the suction port 18. In the figure, 22 is a fuel exchanger, and 23 is a decay heat removal heat exchanger.

According to such a configuration, the primary cold pool 7 is pumped by the electromagnetic pump 4 provided integrally at the lower part of the intermediate heat exchanger 3.
The primary coolant inside the reactor core 2 can be sent into the reactor core 2 from the pressure plenum 9 formed at the bottom of the reactor core 2.
There is no need to place a primary coolant circulation pump around the
The annular space between the core 2 and the primary vessel 1 can be made smaller in the circumferential direction. Thereby, the primary vessel 1 can be downsized, and a fast breeder reactor having a compact structure as a whole can be obtained.

Further, the secondary container 11 is divided into a secondary cold pool 16 and a secondary hot pool 17 by the second partition 15, and the secondary coolant in the secondary cold pool 16 is introduced into the intermediate heat exchanger 3. The secondary coolant that has undergone heat exchange with the primary coolant in the intermediate heat exchanger 3 is introduced to the outside of the secondary coolant inlet pipe 19 to the secondary hot pool 17 (by providing the secondary coolant outlet pipe 20 coaxially, The piping structure in the upper part of the furnace can be simplified and maintainability can be improved.

Furthermore, in this embodiment, since the electromagnetic pump 4 is used as the primary coolant circulation pump, a shaft sealing device is not required and the flow rate of the primary Ar gas can be reduced.

〔Effect of the invention〕

As explained above, the present invention provides a first cooling medium containing a primary coolant.
a secondary container enclosing the primary container and containing a secondary coolant; a roof slab closing the upper openings of the secondary container and the primary container; An installed reactor core, a control rod drive mechanism that inserts control rods into the reactor core and pulls out the control rods from the reactor core, and a control rod drive mechanism that divides the inside of the primary vessel into a primary hot pool and a primary cold boiler. an intermediate heat exchanger that is installed in the primary vessel and exchanges heat between the primary coolant in the hot pool and the secondary coolant; a pressure plenum formed at the lower part of the core; an electromagnetic pump that is integrally provided at the lower part of the intermediate heat exchanger and causes the primary coolant in the cold pool to flow into the reactor core from the pressure plenum; and a secondary hot pool and a secondary cold pool that operate in the secondary vessel. a second partition wall that divides the secondary coolant into water, and a steam generator that is installed in the secondary container and generates steam by exchanging heat with water of the secondary coolant that has exchanged heat with the primary coolant in the intermediate heat exchanger; a secondary coolant circulation pump installed in the secondary container and introducing the secondary coolant flowing out from the steam generator into the secondary cold pool into the intermediate heat exchanger via a secondary coolant inlet pipe; A secondary coolant outlet pipe is provided coaxially outside the secondary coolant inlet pipe and allows the secondary coolant that has exchanged heat with the primary coolant in the intermediate heat exchanger to flow out into the secondary hot pool. It is something. Therefore, the primary coolant in the cold pool can be sent into the core from the pressure plenum formed at the bottom of the core by the electromagnetic pump integrated at the bottom of the intermediate heat exchanger, and the primary coolant around the core can be pumped into the core. Since there is no need to provide a coolant circulation pump, the primary container can be made smaller. In addition, the inside of the secondary container is divided into a secondary hot pool and a secondary cold pool by a second partition, and
Secondary coolant that introduces the secondary coolant from the secondary coolant circulation pump into the intermediate heat exchanger.The secondary coolant that has undergone heat exchange in the intermediate heat exchanger flows out into the hot pool outside the secondary coolant inlet pipe. Since the outlet piping is provided coaxially, the piping structure in the upper part of the furnace can be simplified and maintenance efficiency can be improved.

Therefore, it is possible to obtain a fast breeder reactor that is easy to maintain and has a compact structure.

[Brief explanation of the drawing]

1 and 2 show one embodiment of the present invention, FIG. 1 is a vertical cross-sectional view showing the schematic structure of a fast breeder reactor, FIG. 2 is a plan view of FIG. 1, and FIG. 3 is a conventional fast breeder reactor. FIG. 2 is a longitudinal cross-sectional view showing a fast breeder reactor. 1. Primary vessel, 2. Core, 3. Intermediate heat exchanger,
4... Electromagnetic pump, 6... First bulkhead, 7... Primary cold pool, 8... Primary hot pool, 9... Pressure plenum, 11... Secondary container, 12...・Steam generator, 13...Secondary coolant circulation pump, 14...Roof slab, 15...Second partition wall, 16...Secondary cold pool, 17...Secondary hot pool, 19 ...Secondary coolant inlet piping, 20...Secondary coolant outlet piping. Applicant's agent Patent attorney Takehiko Suzue

Claims (1)

[Claims] A primary container that contains a primary coolant, a secondary container that contains this primary container and also contains a secondary coolant, and a secondary container that contains this primary container and also contains a secondary coolant.
A roof slab that closes a secondary vessel and an upper opening of the primary vessel, a core installed in the primary vessel, and a control rod drive mechanism that inserts control rods into the core and pulls out the control rods from the core. a first partition wall that divides the inside of the primary container into a primary hot pool and a primary cold pool; and a first partition wall installed in the primary container that converts the primary coolant in the hot pool into the secondary coolant. an intermediate heat exchanger for exchanging heat; a pressure plenum formed at the bottom of the core; and a pressure plenum in the cold pool that is integrally provided at the bottom of the intermediate heat exchanger
an electromagnetic pump that causes secondary coolant to flow into the reactor core from the pressure plenum; a second partition wall that divides the inside of the secondary vessel into a secondary hot pool and a secondary cold pool; a steam generator that generates steam by exchanging heat with water for a secondary coolant that has undergone heat exchange with the primary coolant in an intermediate heat exchanger; and a secondary cold pool that is installed in the secondary container and flows from the steam generator. a secondary coolant circulation pump that introduces the secondary coolant flowing out into the intermediate heat exchanger via the secondary coolant inlet piping; A fast breeder reactor characterized in that it comprises a secondary coolant outlet piping that allows the secondary coolant that has undergone heat exchange with the primary coolant in an exchanger to flow out into a secondary hot pool.