JPS63150695A - Fast breeder reactor - 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 [Object of the Invention] (Industrial Application Field) The present invention relates to a fast breeder reactor having a nuclear reactor and a steam generator, and more particularly to a fast breeder reactor that can reduce the overall construction cost. Regarding.

(Prior Art) FIG. 3 shows a conventional fast breeder reactor, in which heat generated in the reactor core 2 is transferred into the reactor 1 through an inflow connecting pipe 4 by a secondary coolant 3 to an intermediate heat exchanger 5. (hereinafter referred to as IHX), where it exchanges heat with the secondary coolant 76, and the primary coolant 3 whose temperature has been lowered by this heat exchange is led to the primary main circulation pump 8 through the outflow connecting pipe 7, where it is heated. It is pressurized and returned to the reactor.

On the other hand, the secondary coolant 76 whose temperature has increased due to heat exchange with the secondary coolant 3 circulates through the secondary cooling system. That is, the secondary coolant 7
6 passes through the secondary hot leg piping 72 to the steam generator 11
(hereinafter referred to as SG), where water is heated to generate steam, then cooled and guided to a secondary main circulation pump 74 via a secondary crossover pipe 73. After being pressurized here, the IHX7 is connected to the secondary cold leg piping 75.
1. Water is supplied to 5G11 through a water supply pipe 15, and the generated steam is sent to a turbine (not shown) through a steam pipe 16.

(Problems to be Solved by the Invention) In the conventional fast breeder reactor having the above configuration, the reactor 1, IHX71, main circulation pump 8.5G11, secondary main circulation pump 74, etc., constitute the plant. Moreover, the piping that connects these devices requires many thermal expansion absorption loops, and it is reported that the entire building becomes huge due to the piping, leading to an increase in the amount of material in the entire plant. There is.

The present invention has been made in consideration of these points,
The present invention aims to provide a fast breeder reactor that can reduce the overall construction cost by eliminating a secondary cooling system consisting of an IHX, a secondary main circulation pump, secondary cooling system piping, etc.

[Structure of the invention]

(Means for Solving the Problems) The present invention provides for sending the coolant flowing into the repeater from the nuclear reactor through the inflow connecting pipe to the steam generator through the hot leg connecting pipe for feeding the coolant, and This fast breeder reactor is configured such that the coolant is returned from the reactor to the repeater through a cold leg connecting pipe for returning coolant, and is further returned from the repeater to the reactor through an outflow connecting pipe.

(Function) Since the coolant flowing into the repeater from the reactor is sent to the steam generator to generate steam, there is no need to provide a secondary cooling system between the reactor and the steam generator.

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

FIGS. 1 and 2 are diagrams showing an embodiment of a fast breeder reactor according to the present invention.

A nuclear reactor 1 containing a core 2 and a primary coolant (hereinafter referred to as coolant) 3 is connected to a repeater 10 by an inflow connecting pipe 4, and a booster pump 20 is built in the repeater 10. . Further, the repeater 10 is connected to the double pipe 5GII by a hot leg connecting pipe 21 having an isolation valve 24a, and further, the double pipe SGI 1 is connected to the relay pipe 10 by a cold leg connecting pipe 23 having an isolation valve 24b. . Furthermore, a trap device 25 for the sodium-water reaction product is installed inside the repeater 10, and this trap device 25 is connected to a primary main circulation pump (hereinafter referred to as main circulation pump) 8.
It is connected to the nuclear reactor 1 by an outflow communication pipe 7 via.

Further, the 5GII is provided with a hydrogen meter 34 for detecting water leaks, and is further equipped with a pressure release valve 33 and a pressure release plate 32 for releasing the pressure inside the SGII. Further, 5GII is connected to a gas accumulator 36 by a pipe having a gas vent valve 35a, and a vapor trap is connected to this gas accumulator 36. Further, a siphon-on break valve 35b is provided between the gas accumulator 36 and the cold leg connecting pipe 23.

In addition, in order to deal with the rise in the liquid level in the reactor 1 that causes a siphon-on break in the SGI 1, an overflow tank 41 is connected to the reactor 1 by an overflow pipe 40, and furthermore, this overflow tank 41 and the reactor 1
It is connected to the pump pipe 43 via a pump pump 42 and having a check valve 44 .

In addition, the repeater 10 has a decay heat removal line (PRAC5).
A heat exchanger tube 26 is built-in.

This PRAC 3 is constructed by connecting a heat transfer tube 26 to an air cooler 28 via a hot leg connection tube 27, and connecting this air cooler 28 to the heat transfer tube 26 via a circulation pump 30 via a cold leg connection tube 29.

Further, the repeater 10 is provided with a bypass flow valve 31. This bypass flow valve 31 normally opens a pressurizing valve 38 connected to a pressurizing header (not shown) to cut off the pressurized flow path, and closes the pressurizing valve 38 when water leaks in the SGI I. , with three pressure relief valves open, repeater 1
A flow path is automatically formed by making the pressure equal to the internal pressure of 0.

Next, details of the repeater 10 will be explained with reference to FIG.

A hot leg inlet nozzle 50 for inflowing coolant is formed in the repeater 10 including an inner shell 57 and an outer shell 54 , and an inflow window 62 is provided between the hot leg inlet nozzle 50 and the inner shell 57 . Furthermore, a center down comer 66 and an annulus tube 67 coaxial with the inner body 57 are disposed inside the inner body 57, one end of the center down comer 66 is connected to the return nozzle 53 from 5GII, and one end of the annulus tube 67 is connected to the S
It is connected to a connection nozzle 52 to GI 1.

Further, a heat transfer tube 26 is disposed approximately in the center of the inner shell 57, and an electromagnetic pump type booster pump 20 that cools the coil with the coolant itself is disposed below the heat transfer tube 26. Furthermore, a thermal shield plate 56 is attached below the booster pump 20 to isolate the high 12i coolant and the low temperature coolant.

A trap device 25 is provided at the bottom of the inner shell 57, and an outflow window 63 is provided between the trap device 25 and the cold leg outlet nozzle 51 formed at the lower end of the repeater 10.

Further, a bypass flow blocking mechanism 58 is provided between the inner shell 57 and the outer shell 54. Further, the bypass flow valve 31 is composed of an upper pipe 69 and a lower pipe 70, and the upper pipe 69 is connected to the cover gas header 59.

The inner shell 57 is fixed with a mounting bolt 64, and is sealed with the outer shell 54 by a sealing mechanism 65 on its upper part. For this reason, the seal mechanism 65 is cut and the mounting bolt 64 is fixed to Jj3?
By removing it, the entire inner shell 57 can be pulled out.

A leak jacket 55 is installed on the outside of the outer shell 54 in order to prevent the coolant 3 from flowing out without limit when the outer shell 54 is damaged.

Next, the operation of this embodiment having such a configuration will be explained.

The coolant 3 that has reached a high temperature in the core 2 of the nuclear reactor 1 enters the repeater 10 through the inflow connecting pipe 4 . The coolant pressurized by the booster pump 20 of the repeater 10 passes through the hot leg connection pipe 21 and enters the double pipe 5G11. Here, the cooling shrine, which has been cooled by exchanging heat with water, passes through the cold leg connection pipe 23 and returns to the repeater 10. Subsequently, the coolant passes through a tramp device 25 for sodium-water reaction products installed inside the repeater 10, reaches the main circulation pump 8, is pressurized here, and reaches the reactor core 2.

The action of the coolant in the repeater 10 in this case will be explained in detail with reference to FIG.

The coolant 3 flowing into the repeater 10 from the hot leg inlet nozzle 50 enters the inside of the inner shell 57 through the inflow window 62. The coolant 3 descends through the inflow window 62, changes the direction of the flow path at the lower end, and rises while being pressurized by the booster pump 20. The coolant 3 pressurized by the booster pump 20 passes through the annulus riser pipe 67 and is sent to the SGI 1 from the connection nozzle 52 to the SGI 1. The coolant 3 that has been heat exchanged in the SGI 1 passes through the center downcomer 66 from the return nozzle 53 from the SGI 1, passes through the sodium-water reaction product trap device 25, flows out from the outflow window 63, and flows out from the cold leg outlet nozzle 51 into atoms. It is sent to the furnace 1 side.

If a water leak occurs in the double pipe 5GII and a sodium-water reaction occurs, the water leak is detected by the hydrogen meter 34, and the isolation valve 24a of 5011.

24b is closed. In addition, when a large-scale leak occurs, the pressure release valve 33 is opened and the pressure is reduced, but the SC,
If the pressure at 11 is still high, the pressure relief plate 32 will automatically burst, releasing the pressure. In addition, if sodium flows out from the leak point and the coolant continues to leak, the gas vent valve 3
5a and the siphon-on break valve 35b are opened, gas is supplied from the gas accumulator 36, and the 5GII
Break on the side. A rise in the liquid level in the reactor 1 when a siphon break occurs is prevented by the coolant 3 flowing into the overflow tank 41 via the overflow pipe 4Q.

In such a case, the bypass flow valve 3 in the repeater 10
1 is opened, the coolant 3 flowing in from the inflow connecting pipe 4 is cooled by the heat transfer tube 26, and is directly led to the reactor core 1 through the outflow connecting pipe 7, and the decay heat from the reactor core 1 is removed.

The operation within the repeater 10 when a water leak occurs in the 5GII will be described in detail below.

5 When exchanging heat on the GII side, bypass flow valve 3
1 is cut off. When shut off, the upper pipe 6 is pressurized by gas pressure from the cover gas header 59.
9 is maintained below the upper end of the lower tube 70.

On the other hand, when SGI 1 is isolated, when the pressure in the five cover gas headers is reduced, the liquid level in the upper pipe 69 rises and reaches the upper part of the lower pipe 70, forming a flow path bus. be done. In this state, the decay heat from the core 1 can be removed by circulating the PRAC8 coolant in the heat transfer tubes 26 and removing heat by the air cooler 28.

During PRACS operation, the coolant 3 flowing in through the inflow window 62 exchanges heat with the heat transfer tube 26 section, and the cooled coolant 3 passes through the bypass flow valve 31 and flows out through the outflow window 63.

In this way, according to this embodiment, from the reactor 1 to the repeater 10
Since steam can be generated in 5G11 by the coolant 3 sent through the 5G11, there is no need to provide a secondary cooling system as in the conventional case, and construction costs can be reduced.

In addition, if water leak occurs within 5GII, 5GII
can be closed by isolation valves 24a, 24b, and the pressure within 5611 can be reduced by pressure relief valve 32 and pressure relief plate 32. Furthermore, if coolant continues to leak into 5GII, a siphon-on break can be performed on the 5G11 side.

Furthermore, since the cooler is cooled by the heat transfer tube 26 in the repeater 10, decay heat from the core can be removed.

〔Effect of the invention〕

According to the present invention, since steam can be generated by sending the coolant from the nuclear reactor to the steam generator, there is no need to install a secondary cooling system between the nuclear reactor and the steam generator as in the past. There is no. Therefore, the IHX, secondary main circulation pump, secondary cooling system piping, etc. that constitute the secondary cooling system can be omitted, and the overall construction cost can be reduced.

[Brief explanation of the drawing]

1 and 2 are diagrams showing one embodiment of a fast breeder reactor according to the present invention, in which FIG. 1 is a schematic system diagram thereof, FIG. 2 is a sectional view showing a repeater, and FIG. 3 is a conventional fast breeder reactor. It is a schematic system diagram of a fast breeder reactor. 1.-Reactor, 2.. Core, 3.. Coolant, 4..
・Inflow communication pipe, 7...Outflow communication pipe, 8...-Tsuko circulation pump, 10...Relayer, 11...Steam generator,
15... Water supply piping, 16... Steam piping, 20... Booster pump, 21... Hot leg connection pipe, 23...
Cold leg connection pipe, 24a, 24b...isolation valve, 2
5... Trap device. Applicant's agent Sato - Male bill I diagram

Claims (1)

[Scope of Claims] 1. Coolant flowing from the nuclear reactor through the inflow connecting pipe to the repeater is sent to the steam generator by a hot leg connection pipe for feeding the coolant, and from the steam generator to the repeater. In addition to returning the coolant through the cold leg connection pipe,
Furthermore, the fast breeder reactor is configured to return from the repeater to the reactor via an outflow connecting pipe. 2. The fast breeder reactor according to claim 1, wherein each of the hot leg connecting pipe and the cold leg connecting pipe is provided with an isolation valve that closes when water leaks from the steam generator. 3. The fast breeder reactor according to claim 2, wherein the repeater is provided with a heat exchanger tube of a decay removal line that is activated when water leaks from the steam generator.