JP2948831B2 - Fast breeder reactor - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a structure of a fast breeder reactor.

[Prior Art] In a conventional tank type fast breeder reactor, a primary coolant of liquid metal is sealed in a reactor vessel accommodating a reactor core,
An intermediate heat exchanger is provided in the container for extracting heat from the container to the outside, in which heat is exchanged between the secondary coolant and the primary coolant of the liquid metal introduced from the outside. In order to obtain the circulating force of the primary cooling system and the secondary cooling system in the reactor vessel, a structure is adopted in which an electromagnetic flow coupler pump is provided in the vessel to circulate both coolants. For example, Japanese Patent Application Publication No. 54495/1986 discloses a basic configuration in which an annular electromagnetic flow coupler pump is combined with an intermediate heat exchanger of a tank type fast breeder reactor and incorporated in a reactor vessel. The vessel and the annular electromagnetic flow coupler pump are shown in one piece.
In this case, the stator coil of the electromagnetic pump is immersed in the primary coolant in the reactor vessel. Further, in this prior art, the flow paths of the intermediate heat exchange section and the flow coupler pump are the same.

[Problems to be Solved by the Invention] In the above-described conventional technology, it is difficult to cool the stator coil of the coupler pump. Further, since the flow paths of the intermediate heat exchange section and the flow coupler pump are the same, their manufacture and assembly are difficult. In addition, the prior art has not been sufficiently streamlined in terms of structure when actually manufacturing a fast breeder reactor, for example, because the lengths of the flow passages of the primary cooling system and the secondary cooling system are long.

An object of the present invention is to provide a structure of a fast breeder reactor having a structure that solves the above-mentioned problems.

[Means for Solving the Problems] The above-mentioned problem is achieved by housing a reactor core in a cylindrical reactor vessel, and taking out heat inside the reactor and a primary cooling system made of a liquid metal for cooling the reactor core. Made of liquid metal for
An intermediate exchanger for exchanging heat in a secondary cooling system and an electromagnetic flow coupler pump for transferring these coolants, comprising: an annular intermediate exchanger disposed in close proximity to the inner wall of the cylindrical reactor vessel; The problem is solved by providing an annular electromagnetic flow coupler pump located close to the inner wall of the furnace vessel and below the annular intermediate exchanger.

[Operation] An electromagnetic flow coupler pump and an intermediate heat exchanger are formed in the reactor vessel in an annular shape close to the inner wall of the reactor vessel, and the electromagnetic flow coupler pump is installed at a lower portion of the intermediate heat exchanger. The arrangement of these devices in the vessel can be rationalized, the size of the reactor can be reduced, and the length of the primary coolant flow path for cooling the core of the core-heat exchanger-pump-core can be minimized. I can do things.

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

FIG. 2 is a cooling system diagram of a liquid metal-cooled nuclear reactor using an annular flow coupler pump, and the flow of the entire coolant will be described with reference to FIG.

The cooling system of a liquid metal-cooled reactor generally transfers heat from a primary coolant that cools the reactor core to a secondary coolant via an intermediate heat exchanger, and a steam generator converts water into steam with the heat of the secondary coolant. It is configured to generate power using a turbine generator.

The primary coolant flows from the cold plenum 6 into the core 1 as shown by the white arrow 15, and the heated primary coolant flows from the hot plenum 7 through the inlet at the upper part of the annular intermediate heat exchanger 5 to be transferred. The heat is exchanged with the secondary coolant while descending outside the heat pipe, the temperature is lowered, and after flowing out of the outlet, it flows into the primary flow path of the annular electromagnetic flow coupler pump 4 from the primary inlet of the pump 4. In the primary flow path, the primary coolant is given a driving force by the magnetic field generated by the electromagnet 10 (FIG. 1) of the annular electromagnetic flow coupler pump 4 and the electromagnetic force generated by the fluid force of the secondary coolant, and again in the lower part of the core. After flowing into the cold plenum 6, a primary coolant circulation channel is formed.

Further, the secondary cooling material is discharged to the secondary inlet plenum 8 installed below the annular intermediate heat exchanger 5 by the driving force of the secondary circulation pump 18 as shown by the black arrow 16 and the annular electromagnetic flow coupler pump 4 flows into a secondary flow path of the pump 4 from a secondary-side inlet provided on a lower inner wall of the pump 4 and rises. The secondary coolant flowing out of the secondary side outlet provided on the upper inner wall of the annular electromagnetic flow coupler pump 4 flows into the annular intermediate heat exchanger 5 from the lower tube sheet, and heats the primary coolant inside the heat transfer tube. After ascending while exchanging, and flowing out of the upper pipe portion, it is guided to the steam generator 19 by piping. Water in the steam generator 19
The secondary coolant that has exchanged heat with the steam is circulated again by the secondary circulation pump 18.

The steam generated by the steam generator 19 is supplied to a steam turbine or the like that drives a generator, and is consumed as a power source. Further, as shown by the hatched arrow 17, the air flowing from the lower outer wall of the reactor vessel 2 naturally cools the reactor vessel 2 while ascending the natural ventilation path 9 provided outside the reactor vessel 2. During the power output operation, it plays a role of a ventilation air conditioning system of the reactor vessel 2, and plays a role of a decay heat removal system after the reactor trip.

The reactor structure will be described with reference to the longitudinal sectional view of FIG. As shown in the figure, an annular electromagnetic flow coupler pump 4 is installed on the inner periphery of the reactor vessel 2 at the upper part of the reactor core 1, and further above the annular electromagnetic flow coupler pump 4.
An annular intermediate heat exchanger 5 that is structurally connected to the flow path is provided. Further, a primary plenum partition wall 20 is provided below these to divide into a low-pressure primary hot plenum 7 and a high-pressure primary cold plenum 6. This primary plenum partition 20
Annular electromagnetic flow coupler pump 4, Annular intermediate heat exchanger 5
And a supporting structure for supporting a structure connecting them from below. The thermal expansion of the annular intermediate heat exchanger 5 with respect to the reactor vessel 2 is absorbed by the bellows 14 provided on the roof slab 33.

The plan layout (section AA) of the reactor vessel 2, the annular electromagnetic flow coupler pump 4, and the annular intermediate heat exchanger 5 is as shown in FIG. The inside of the vessel 5 is descending.

FIG. 5 is a bird's-eye view of the annular electromagnetic flow coupler pump main body, and FIG. 6 is a longitudinal sectional view showing the structures of the annular electromagnetic flow coupler pump and the annular intermediate heat exchanger. The annular electromagnetic flow coupler pump includes a flow duct 13 formed by a partition wall 12, an inner wall 23, and an outer wall 24, an outer core 21, and an inner core 22.
And an electromagnetic coil 10. The secondary coolant driven by the secondary circulation pump passes through the inside of the flow duct 13 partitioned by the partition wall 12 as indicated by a black arrow 16.
When ascending every other, the outer core 21 generates an electromagnetic force induced by the inner core 22 and the electromagnetic coil 10, and the primary coolant in the flow duct 13 adjacent to the inner core 22 by the force as shown by a white arrow 15. Drive down. Pump primary side inlet 2
8, and the pump secondary-side inlet 29 are provided in every other flow duct as shown in the figure. That is, when the annular pump is operated, the secondary coolant discharged at a high pressure passes through the secondary side inlet 29 at the lower part of the annular electromagnetic flow coupler pump, and passes through the inner wall 23, the outer wall 24, and the partition wall of the annular electromagnetic flow coupler pump. It enters the secondary flow path of the formed flow duct 13 and rises and flows in the secondary flow path. When the secondary coolant flows upward in the secondary flow path, the secondary coolant crosses the magnetic field generated by the electromagnet 10. For this reason, an annular current along both walls 23 and 24 is induced in the annular region surrounded by the inner peripheral wall 23 and the outer peripheral wall 24. When this current causes the primary coolant in the primary flow path to receive a downward acting force in an environment of a radial magnetic field perpendicular to both walls 23 and 24, the primary coolant becomes less than the flow of the secondary coolant. It flows downward, which is the opposite direction. These principles are based on the so-called Fleming right and left hand rule. An annular electromagnetic flow coupler pump 4 and an annular intermediate heat exchanger 5 are installed around the inner wall of the reactor vessel 2, and these structures are installed above the primary plenum partition 20 to form an integral structure. The annular electromagnetic flow coupler pump 4 includes an outer core 21, an inner core 22, a coil 10, and an inner wall 2 for forming a flow path.
3, the outer wall 24, and a partition plate (not shown) for separating the primary coolant and the secondary coolant, the inner wall 23,
Through the annular intermediate heat exchanger lower plenum 25, it is connected to the outer wall 26 of the annular intermediate heat exchanger 5. The annular intermediate exchanger 5 is a straight-tube heat exchanger in which a secondary coolant flows inside the heat transfer tubes. An annular (annular) primary coolant area is provided between the reactor vessel 2 and the outer wall 35 of the annular intermediate heat exchanger to communicate with the primary inlet of the pump. As a result, during the operation of the reactor, the liquid level in the annulus decreases by the pressure loss on the primary side of the intermediate heat exchanger (about 2 m), so that the temperature of the upper wall of the reactor vessel can be lowered. In general, since the reactor vessel of the high-speed breeding passage is suspended from the upper part, the lowering of the liquid level in the annulus is very advantageous in terms of the integrity of the reactor vessel structure. Open arrows in Fig. 6
As shown at 15, the primary coolant heated in the reactor core is supplied to the intermediate heat exchanger primary side inlet provided at the upper part of the annular intermediate exchanger 5.
It flows in from 27 and descends outside the heat transfer tube while being removed by the secondary coolant. This primary coolant is supplied to a pump primary side inlet 28 provided above the annular electromagnetic flow coupler pump 4.
After flowing into the primary flow path in the pump and being given a driving force, it is discharged to the cold plenum 6. The secondary coolant is discharged from the secondary circulation pump as indicated by a black arrow 16, passes through the inside of the annular intermediate heat exchanger 5 through a pipe, and flows into the secondary system inlet plenum 8. After that, it flows into a secondary flow path in the pump from a pump secondary side inlet 29 provided in a lower part of the annular electromagnetic flow coupler pump inner wall 23, rises, and is provided in an upper part of the annular electromagnetic flow coupler pump inner wall 23. From the pump secondary-side outlet 30, the heat flows into the heat transfer tube of the annular intermediate heat exchanger 5 via the annular intermediate heat exchanger inlet plenum 25. Thereafter, the secondary coolant heated by the primary coolant while rising in the heat transfer tube flows out of the upper plenum 31 of the annular intermediate heat exchanger, and is conveyed to the steam generator.

As shown by a hatched arrow 17 in FIG. 1, the cooling air cools the reactor vessel 2 and the electromagnetic coil 10 while moving up the natural ventilation path 9 provided outside the safety vessel 3. When the heat transfer area for cooling is insufficient, as shown in FIG.
The fins 11 can be attached to the outer iron core 21 to improve the cooling effect.

As can be seen from FIG. 3, the annular flow coupler pump 4, the annular intermediate heat exchanger 5, and the structure connecting them are annular and have an integral structure and are housed in the reactor vessel 2. If this integral structure is divided into a plurality of sectors in a fan shape and housed in a nuclear reactor vessel, manufacture and assembly are greatly simplified. This figure is shown in FIG. FIG. 8 is a bird's-eye view showing one sector model divided into four parts.

According to the above-described embodiment, since the intermediate heat exchanger and the pump are assembled into the reactor vessel in a ring shape, there is an effect that the reactor structure can be reduced in size.

In addition, by arranging the annular flow coupler pump above the core, the amount of activation of the secondary coolant can be reduced because the secondary coolant is separated from the high activity region.

In addition, the annular electromagnetic flow coupler pump, the annular intermediate heat exchanger and the structure connecting these are manufactured in multiple parts,
Since it is housed in the reactor vessel, the manufacture and assembly of the reactor structure can be greatly simplified.

Further, by providing a ventilation path outside the safety vessel, the decay heat removal system in the reactor vessel can be eliminated, which contributes to downsizing of the reactor structure and cooling of the coil.

[Effects of the Invention] According to the present invention, the intermediate heat exchanger and the electromagnetic flow coupler pump are formed in an annular shape close to the inner wall of the reactor vessel, so that the arrangement of the vessel is rationalized, thereby reducing the size of the entire reactor. can do.

According to the present invention, the primary coolant can reduce the flow path length of the core → heat exchanger → pump → core, and the primary coolant and the secondary coolant are annular electromagnetic flow coupler pumps. The structure of the reactor can be made compact because the flow path wall, annular intermediate heat exchanger wall, and secondary system inlet plenum can be isolated, and the flow path for the secondary coolant can be minimized. it can.

In addition, by providing a natural ventilation path outside the safety vessel, the decay heat removal system inside the reactor vessel can be eliminated and the electromagnetic coil can be cooled, so that the reactor structure can be further downsized and the coil cooling can be performed. This has the effect of not requiring the development of equipment or high-temperature coils.

Further, since the annular electromagnetic flow coupler pump and the annular intermediate heat exchanger can be manufactured separately and housed in the reactor vessel, the manufacture and assembly of the reactor structure can be simplified.

As described above, it is possible to achieve a reactor structure of a fast breeder reactor that is more integrated than before.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a fast breeder reactor according to one embodiment of the present invention, FIG. 2 is a cooling system diagram of an annular flow coupler furnace, FIG.
The figure is a sectional view taken along the line AA in FIG. 1, FIG. 4 is a view in which the annular electromagnetic flow coupler pump and annular intermediate heat exchanger in FIG. 3 are divided into four parts and accommodated in a reactor vessel, and FIG. FIG. 6 is a vertical sectional view showing details of the annular flow coupler pump and the annular intermediate heat exchanger of FIG. 1, FIG. 7 is a BB sectional view of FIG. 6, and FIG. Fig. 2 shows a divided model bird's-eye view in which the annular electromagnetic flow coupler pump and the annular intermediate heat exchanger are divided into four parts and assembled. 8: Secondary system inlet plenum, 9: Ventilation path, 11: Fin, 15: Primary coolant flow, 16: Secondary coolant flow, 17: Air flow, 20: Primary plenum bulkhead, 24
…… the outer wall of the annular electromagnetic flow coupler pump, 25 …… the lower plenum of the annular intermediate heat exchanger, 26 …… the inner wall of the annular intermediate heat exchanger.

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Noboru 3-1-1, Sachimachi, Hitachi-shi, Ibaraki Inside Hitachi, Ltd. Hitachi Plant (72) Inventor Takashi Ikeda 1168 Moriyama-cho, Hitachi-shi, Ibaraki Co., Ltd. Hitachi Energy Research Laboratory (56) References Moriyasu Jobai, et al., “Advanced Technology and Ripple Effect on Industry” Future Technology in Fast Breeder Reactors, Proc. Part. 1, p 1.159-1.162 (1987) (58) Fields investigated (Int. Cl. ⁶ , DB name) G21C 15/247 G21C 15/02 G21C 1/02 JOIS

Claims (5)

(57) [Claims] 1. A primary cooling system made of a liquid metal for housing a reactor core in a cylindrical reactor vessel and cooling the core, and a secondary cooling system made of a liquid metal for extracting heat in the reactor to the outside. An intermediate heat exchanger for exchanging heat in the system and an electromagnetic flow coupler pump for transferring these coolants, an annular intermediate heat exchanger disposed close to the inner wall of the cylindrical reactor vessel, the cylindrical reactor vessel An annular electromagnetic flow coupler pump disposed close to the inner wall of the annular intermediate heat exchanger and disposed below the annular intermediate heat exchanger, wherein a stator coil of the annular electromagnetic flow coupler pump is provided outside a reactor vessel, A fast breeder reactor wherein a flow path of a coupler pump is arranged close to an inner wall of the reactor vessel. 2. The invention according to claim 1, wherein a conduit for guiding a secondary coolant introduced from outside the reactor vessel to a plenum of the secondary coolant passes through the inside of the annular intermediate heat exchanger. A fast breeder reactor characterized by being placed in 3. The reactor according to claim 1, wherein the interior of the reactor vessel is partitioned by a partition into a high-pressure plenum portion including a core portion and a low-pressure plenum portion belonging to a core outlet flow path system. A fast breeder reactor, wherein the annular electromagnetic flow coupler pump and the like are arranged above the partition, that is, in the low-pressure plenum. 4. The method according to claim 1, wherein the annular intermediate heat exchanger, the annular electromagnetic flow coupler pump, and the like are separated from a reactor vessel and are divided into a plurality of fan-shaped parts. A fast breeder reactor characterized in that it is formed into a ring-shaped unit when it is installed in a reactor vessel. 5. The invention according to claim 1, wherein a gap is provided between the inner wall of the reactor vessel and the annular intermediate heat exchanger, and the gap is provided between the inner side of the reactor and the inlet side of the primary cooling system of the annular electromagnetic flow coupler pump. A fast breeder reactor characterized in that it is formed in a primary coolant region that conducts.