JPH0659065A - Double tank type nuclear reactor - Google Patents

Abstract

PURPOSE:To blowoff only gaseous components in a secondary container by constituting a cylindrical shell of a manometer seal in a structure with a large diameter part drooping to reach the inside of a double cylindrical tub from a roof slab and expanded upward in diameter. CONSTITUTION:When pressure inside of a secondary vessel 31 rises higher than set pressure, a blowoff system breakdown plate 58 is ruptured and gaseous reacting product materials such as H and others in the secondary vessel 31 pass a blowoff system piping 57 and are blown off to the air from an atmospheric blowoff part 61. The output port of the piping 57 is arranged adjacent to the inwall of a double cylindrical tub 34a of a manometer seal 34, that is, to the peripheral wall of the secondary vessel 31 and on the back face side of the secondary vessel 31. Additionally. on the upper part of a cylindrical shell 34b, a large diametrical part 34d is formed. Consequently, swirling flow components of a refrigerant (Na) in the secondary vessel 31 moving to the side of the manometer seal 34 are promoted and movement of Na to the inside of the piping 57 is restrained by a principle of centrifugation. Accordingly, only gaseous product materials flow in the piping 57, and flow of Na is prevented. Consequently, it becomes needless to provide a cyclone separator.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a double tank type reactor having a double vessel using liquid metal such as sodium as a coolant, and particularly in a steam generator, for example, sodium-
The present invention relates to a dual tank reactor in which a gas product generated in a water reaction accident can be discharged to the outside without using a cyclone separator.

[0002]

2. Description of the Related Art FIG. 3 shows a conventional general structure of the above-mentioned double tank reactor. In the figure, reference numeral 1 is a secondary container, and this secondary container 1 is a base slab 2 The base slab 2 is installed above, and an upper end opening of the base slab 2 is closed by a roof slab 3. Then, a manometer seal 4 for absorbing thermal expansion of the secondary container 1 is provided at a connecting portion between the secondary container 1 and the roof slab 3.

As shown in detail in FIG. 4, the manometer seal 4 is hung from the roof slab 3 and a groove-shaped double cylindrical trough 4 a which is connected to the peripheral edge of the upper end opening of the secondary container 1 and opens upward. The lower end is composed of a cylindrical barrel 4b inserted into the double cylindrical gutter 4a and a sealing liquid 4c injected into the double cylindrical gutter 4a. The sealing liquid 4c is formed of, for example, a molten metal such as solder or mercury,
With the lower end of b being submerged in the sealing liquid 4c, the non-contact double cylindrical gutter 4a and the cylindrical barrel 4b are sealed. The inner wall of the double cylindrical gutter 4a is configured as a peripheral wall of the secondary container 2.

At the center of the inside of the secondary container 1, there is arranged a vase-shaped primary container 5 having a reduced diameter at the upper end. The primary container 5 is installed on the bottom mirror of the secondary container 1. The upper end penetrates the roof slab 3. The upper end opening of the secondary container 5 is closed by a shield plug 6 suspended from the roof slab 3.

A core 7 is arranged in the center of the primary container 5, and the core 7 is arranged at the bottom of the primary container 5 via a core inlet pressure plenum 8. Core 7
At the upper end position, a primary system partition wall 11 is provided which divides the interior of the primary container 5 into an upper primary high temperature pool 9 and a lower primary low temperature pool 10.

A plurality of intermediate heat exchangers 12 and primary coolant electromagnetic pumps 13 are arranged at required intervals in the circumferential direction at the outer peripheral position of the core 7 in the primary vessel 5 while penetrating the primary system partition walls 11. The upper ends of these are suspended and supported by a stand 14 provided on an upper shoulder portion 5a of the primary container 5 having a pot shape, via a seal ring and a bolt (not shown).

The intermediate heat exchanger 12 includes a primary high temperature pool 9
Further, openings for inflow and outflow of the primary coolant are respectively provided at corresponding positions of the primary low-temperature pool 10 and the high-temperature primary coolant in the primary high-temperature pool 9 is fed from the upper opening to the intermediate heat exchanger 12. Flows into the interior of the intermediate heat exchanger 12, and heat is exchanged with a secondary coolant described later in the intermediate heat exchanger 12. Then, the primary coolant after heat exchange is delivered to the primary low temperature pool 10 through the opening at the lower end.

Further, the primary coolant electromagnetic pump 13 has its suction port opened in the primary low temperature pool 10 and its discharge port directly connected to the core inlet pressure plenum 8. The primary coolant electromagnetic pump 13 The primary coolant in the primary low-temperature pool 10 sucked by is sent to the core 7 via the core inlet pressure plenum 8.

Bellows 15 are incorporated in the lower ends of the shells of the primary coolant electromagnetic pump 13 and the intermediate heat exchanger 12, respectively, so that thermal expansion can be absorbed, and the lower end of the intermediate heat exchanger 12 is absorbed. The secondary coolant electromagnetic pump 1
6 is attached to this secondary coolant electromagnetic pump 16
The secondary coolant is sucked through the through hole 17 provided at the bottom of the primary container 5 and fed to the intermediate heat exchanger 12. In this intermediate heat exchanger 12, a secondary coolant flows inside a heat transfer tube (not shown) and a primary coolant flows outside the heat transfer tube.

On the other hand, inside the secondary container 1, a secondary system partition 18 is provided at an intermediate portion in the vertical direction, and inside the secondary container 1, the secondary system partition 18 allows the primary container to be provided. 5 is divided into an upper secondary high temperature pool 19 and a lower secondary high temperature pool 20 having a liquid surface above the upper shoulder portion 5a. Then, the secondary coolant that has undergone heat exchange in the intermediate heat exchanger 12 is directly discharged from the upper end portion of the intermediate heat exchanger 12 into the secondary high temperature pool 19.

Further, inside the secondary container 1, a plurality of steam generators 21 are arranged at required intervals in the circumferential direction in a state of penetrating the secondary system partition wall 18. Each of these steam generators 21 is arranged.
Are suspended from the roof slab 3. At the positions corresponding to the pools 19 and 20 of the steam generator 21,
Each of the openings has a secondary high temperature pool 19
The high temperature secondary coolant in the inside flows into the steam generator 21 through the opening in the upper part and exchanges heat with the water sent through the water supply pipe 22 and the secondary cooling after the heat exchange. The material is delivered to the secondary low temperature pool 20 through the lower opening.

The secondary coolant flows outside a heat transfer pipe (not shown) arranged in the steam generator 21, and water from the water supply pipe 22 flows inside the heat transfer pipe. Then, the superheated steam generated by the heat exchange in the steam generator 21 is sent to the steam turbine (not shown) through the water supply pipe 22 and the superheated steam pipe 23 provided at the top of the steam generator 21. There is.

In FIG. 3, reference numeral 24 is a control rod drive mechanism provided on the shielding plug 6, reference numeral 25 is a telescopic cylinder for absorbing thermal expansion provided at the upper end of the primary container 5, and reference numeral 26 is. , Bellows for thermal expansion absorption provided in the intermediate portions of the intermediate heat exchanger 12 and the steam generator 21, respectively.

One end of the discharge system pipe 27 is connected to the cylindrical body 4b of the manometer seal 4, and the discharge system breaks down in the middle of the discharge system pipe 27 at a pressure higher than a predetermined set pressure. A plate 28 is interposed, and a cyclone separator 29 having an atmosphere discharge portion 30 is connected to the other end of the discharge system pipe 27 to form a pressure adjusting mechanism 31 that suppresses a pressure increase in the secondary container 1.

That is, for example, when a sodium-water reaction accident occurs in the steam generator 21 and the pressure in the secondary container 1 rises, the release system destruction plate 28 ruptures and the secondary container 21.
The pressure due to the gas inside is released to the atmosphere, and at this time, the fluid flowing in the discharge system pipe 27 is separated into gas (reaction product) and liquid (sodium) by the cyclone separator 29, and only the gas reaction product is obtained. The air is emitted from the air emission unit 30.

[0016]

However, in the above-mentioned conventional example, when the release system rupture plate 28 ruptures due to a pressure increase in the secondary container 1 due to a sodium-water reaction accident in the steam generator 21, for example, Since the gas component (reaction product) and the liquid component (sodium) flow in the discharge system pipe 27 in a mixed state, it is necessary to provide a cyclone separator 29 at the end of the pipe 27 for separating the two. Moreover, the cyclone separator 29 is usually large enough to accommodate the sodium volume of one steam generator. Therefore, when arranging various devices in the building that houses the nuclear reactor, the area occupied by the cyclone separator 29 becomes considerably large, and the arrangement of the various devices in the building is considerably restricted by the existence of the cyclone separator 29. There was a problem that I received it.

In view of the above, the present invention releases only the gas component in the secondary container to the atmosphere without using a cyclone separator when the release system destruction plate of the pressure regulating mechanism ruptures due to the pressure increase in the secondary container. The purpose is to provide what has been made possible.

[0018]

To achieve the above object, a dual tank reactor according to the present invention comprises a secondary container installed on a base slab for accommodating a steam generator, and a secondary container in the secondary container. And a primary container for storing the core inside,
A roof slab installed in the upper end opening of the base slab, a manometer seal provided between the roof slab and the upper opening of the secondary container, and connected to the manometer seal via a discharge system pipe. In a double tank type nuclear reactor having a pressure regulating mechanism for suppressing a pressure increase inside the secondary container, a double cylinder having a groove shape connected to the upper end opening peripheral edge of the secondary container and opening upward From a gutter, a cylindrical barrel having a large diameter part that hangs down from the roof slab to reach the inside of the double cylindrical gutter, and has a large diameter portion that expands in diameter at the upper part, and a liquid such as molten metal injected into the double cylindrical gutter While constituting the manometer seal, the discharge system pipe of the pressure regulating mechanism passes through the large diameter portion of the cylindrical barrel so that the end outlet of the pipe reaches a position close to the inner wall of the double cylindrical gutter. Placed in It is an feature.

[0019]

According to the present invention configured as described above, for example, when a sodium-water reaction accident occurs in the steam generator and the pressure in the secondary container reaches a predetermined pressure, the discharge system piping is in the middle. The interposing release system destruction plate ruptures and the inside of the secondary container is opened to the atmosphere through the release system piping. At this time, in the sodium that migrates from the gap between the container and the roof slab in the secondary container to the manometer seal side, the generation of the swirling flow component is promoted through the enlarged diameter portion provided in the cylindrical barrel, and the centrifugal force is increased. By the principle of separation, the sodium is prevented from flowing into the discharge system pipe in which the intake is located close to the inner wall of the double cylindrical gutter, which allows only the gas product to flow in the discharge system pipe. , A cyclone separator can be dispensed with.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 shows an example of a dual tank type nuclear reactor in this embodiment. In the figure, reference numeral 31 is a secondary container, and this secondary container 31 is installed on a base slab 32. A roof slab 33 is installed at the upper end opening of the base slab 32. A manometer seal 34 is provided between the upper end opening of the secondary container 31 and the roof slab 33.

FIG. 2 shows the manometer seal 34 in detail. That is, this manometer seal 34
Is a groove-shaped double cylindrical gutter 34a that is provided on the outer peripheral edge of the upper end opening of the secondary container 31 and that opens upward, and a cylinder that hangs down from the roof slab 33 and the lower end is inserted into the double cylindrical gutter 34a. It is composed of a barrel 34b and a sealing liquid 34c which is injected into the double cylindrical trough 34a. The sealing liquid 34c is formed of a molten metal such as solder or mercury,
With the lower end of the cylindrical body 34b submerged in the seal liquid 34c, a non-contact double cylindrical trough 34a and a cylindrical body 34b are provided.
It is designed to seal between and.

In the manometer seal 34 having such a structure, the radial position of the cylindrical barrel 34b is set so that the size thereof is optimized in the operating state of the nuclear reactor.
4a is arranged so as to reach almost the central portion, and the cylindrical body 3
The submersion depth and the axial position of 4b in the seal liquid 34c are also arranged so as to reach the target point in the operating state. Further, an enlarged large diameter portion 34d is formed on the upper portion of the cylindrical body 34b, and the discharge system pipe 57 is formed.
Is disposed at a position where it passes through the large diameter portion 34a and the end outlet is close to the inner wall of the double cylindrical gutter 34a.

Here, the double cylindrical trough 34a is constructed by fixing the lower end of a member having a substantially cylindrical lower recess to the outer peripheral surface of the secondary container 31, and the inner wall of the double cylindrical trough 34a, that is, the double cylindrical trough 34a. The upper end of the peripheral wall of the next container 31 is extended upward and arranged so that the outlet of the discharge system pipe 57 is below the upper end thereof.

At the center of the inside of the secondary container 31, there is arranged a vase-shaped primary container 35 whose upper end is reduced in diameter. The primary container 35 is installed on the bottom mirror of the secondary container 31, and the upper end is It penetrates the roof slab 33. The upper end opening of the secondary container 35 is closed by a shield plug 36 suspended from the roof slab 33.

A core 37 is arranged in the center of the primary container 35, and the core 37 is arranged at the bottom of the primary container 35 via a core inlet pressure plenum 38.
Further, at the upper end position of the reactor core 37, a primary system partition wall 41 for partitioning the interior of the primary container 35 into an upper primary high temperature pool 39 and a lower primary low temperature pool 40 is provided.

At the outer peripheral position of the core 37 in the primary vessel 35, the intermediate heat exchanger 4 is penetrated through the primary system partition wall 41.
Two and a plurality of primary coolant electromagnetic pumps 43 are arranged at required intervals in the circumferential direction, and their upper ends are not shown in a stand 44 provided on the upper shoulder portion 35a of the pot-shaped primary container 35. It is suspended and supported via a seal ring and bolts.

In the intermediate heat exchanger 42, the primary high temperature pool 3
9 and primary low-temperature pool 40 are provided at corresponding positions with openings for inflow and outflow of the primary coolant, respectively, and the high-temperature primary coolant in the primary high-temperature pool 39 is transferred from the upper opening to the intermediate heat exchanger. It flows into 42 and exchanges heat with a secondary coolant, which will be described later, in the intermediate heat exchanger 42. After the heat exchange, the primary coolant flows from the opening at the lower end to the primary low temperature pool 4
It is designed to be sent to 0.

The suction port of the primary coolant electromagnetic pump 43 is open in the primary low temperature pool 40, and the discharge port is directly connected to the core inlet pressure plenum 38. The primary coolant electromagnetic pump 43 sucks the primary coolant electromagnetic pump 43. The primary coolant in the primary low-temperature pool 40 is cooled by the core inlet pressure plenum 38.
It is sent to the core 37 via the.

Bellows 45 can be incorporated in the lower end portions of the shells of the primary coolant electromagnetic pump 43 and the intermediate heat exchanger 42 to absorb thermal expansion, and the intermediate heat exchanger 42 can have its lower end portions. The secondary coolant electromagnetic pump 46
Is attached to the secondary coolant electromagnetic pump 46.
Is configured to suck the secondary coolant through the through hole 47 provided at the bottom of the primary container 35 and send the secondary coolant to the intermediate heat exchanger 42. In the intermediate heat exchanger 42, the secondary coolant flows inside the heat transfer tube (not shown), and the primary coolant flows outside the heat transfer tube.

On the other hand, inside the secondary container 31, a secondary partition wall 48 is provided at an approximately middle portion in the vertical direction, and the inside of the secondary container 31 is covered by the secondary partition wall 48.
It is divided into an upper secondary high temperature pool 49 and a lower secondary high temperature pool 50 having a liquid surface above the upper shoulder portion 35a. Then, the secondary coolant that has undergone heat exchange in the intermediate heat exchanger 42 is directly discharged from the upper end portion of the intermediate heat exchanger 42 into the secondary high temperature pool 49.

Further, inside the secondary container 31, a plurality of steam generators 51 are arranged at required intervals in the circumferential direction in a state of penetrating the secondary system partition wall 48, and each of these steam generators 51 is arranged. Are suspended from the roof slab 33. Openings are provided at positions corresponding to the pools 49, 50 of the steam generator 51, and the high-temperature secondary coolant in the secondary high-temperature pool 49 is discharged from the upper opening to the steam generator. Heat exchange is performed with the water that flows into the inside 51 and is sent through the water supply pipe 52, and the secondary coolant after the heat exchange is sent to the secondary low temperature pool 50 from the opening in the lower part. It is like this.

The secondary coolant flows outside the heat transfer pipe (not shown) arranged in the steam generator 51, and the water from the water supply pipe 52 flows inside the heat transfer pipe. ing. Then, the superheated steam generated by the heat exchange in the steam generator 51 is sent to the steam turbine (not shown) via the water supply pipe 52 and the superheated steam pipe 53 provided at the top of the steam generator 51. There is.

The control rod drive mechanism 5 is attached to the shield plug 36.
4, an expansion cylinder 55 for absorbing thermal expansion is provided at an upper end portion of the primary container 35, and a bellows 56 for absorbing thermal expansion is provided at intermediate portions of the intermediate heat exchanger 42 and the steam generator 51. Has been.

By the way, the steam generator 5 in the secondary container 31
In No. 1, for example, when a sodium-water reaction accident occurs, the pressure of the internal space surrounded by the secondary container 31 and the roof slab 33 rises due to hydrogen gas which is a main reaction product thereof. In order to avoid such a phenomenon, the following configuration is provided.

That is, in the middle of the discharge system pipe 57, one end of which is connected to the double cylindrical trough 34b of the manometer seal 34, a discharge system destruction plate 58 for breaking at a constant pressure is provided and this discharge is performed. Atmosphere discharge part 61 is connected to the other end of system pipe 57 to form pressure adjusting mechanism 62.
As a result, when the pressure in the secondary container 31 reaches a predetermined pressure, the release system destruction plate 58 is broken, and the interior of the secondary container 31 communicates with the atmosphere via the release system pipe 57, and is released into the atmosphere. The hydrogen gas in the secondary container 31 can be released from the portion 61 to the atmosphere.

Next, the operation of this embodiment will be described.

The primary coolant superheated in the core 37 flows into the intermediate heat exchanger 42 via the primary high temperature pool 39,
After performing heat exchange with the secondary coolant in the intermediate heat exchanger 42, it is sent to the primary low temperature pool 40. The primary coolant in the primary low temperature pool 40 is the primary coolant electromagnetic pump 4
3 and is sent to the core 37 through the core inlet pressure plenum 38.

On the other hand, the secondary coolant superheated by heat exchange in the intermediate heat exchanger 42 is discharged from the upper end of the intermediate heat exchanger 42 to the secondary high temperature pool 49, and further the steam generator 5
1, and heat exchange with the water from the water supply pipe 52 is performed. The superheated steam generated by this heat exchange is sent to a steam turbine (not shown) via the superheated steam pipe 53, and the secondary coolant whose temperature has been lowered by the heat exchange is sent to the secondary low temperature pool 50. The secondary coolant in the secondary low temperature pool 50 is sucked by the secondary coolant electromagnetic pump 46 through the through hole 47 and sent to the intermediate heat exchanger 42.

By the way, since the secondary container 31 during the operation of the nuclear reactor is heated by the high temperature secondary coolant, this average temperature is, for example, about 400 ° C., and at the time of an accident, a higher temperature, for example, 600 ° C. It reaches the level.
Then, due to the temperature difference from that at the time of installation, the secondary container 3
The axial thermal expansion amount of No. 1 is, for example, 100 to 200 mm, and the radial thermal expansion amount is, for example, 30 to 60 mm.

Here, the temperature difference between the cylindrical body 34b of the manometer seal 34 and that at the time of installation is relatively small, and therefore, the double cylindrical trough 34a connected to the upper end of the secondary container 31.
The displacement caused by the thermal expansion of the cylinder is almost unchanged.
It becomes relative position fluctuation with. If the amount of thermal expansion is within the above-mentioned range, it can be sufficiently absorbed by properly setting the dimensions of the double cylindrical gutter 34a.

Further, the secondary container 3 in a normal operating state
The pressure of the inert gas such as argon gas in 1 is, for example, 10
Since it is about 0 to 500 mmAg, for example, the sealing liquid 3
If the specific weight of 4c is about 10 g / cm ³ , the sealing property can be ensured when the difference in liquid level between the inner and outer surfaces is about 10 to 50 mm.

On the other hand, as a potential pressure increase factor of the secondary container 31, there is a sodium-water reaction due to the damage of the heat transfer tube of the steam generator 51 in the secondary container 31. When this sodium-water reaction occurs, it is important to release the pressure in the secondary container 31 as soon as possible so as not to impair the reliability of the primary container 35 and the core 37. This pressure release is performed by the pressure adjusting mechanism 62 including the release system destruction plate 58 and the like.

That is, the release system breaking plate 58 is set so as to break at a constant pressure, for example, a pressure of 0.5 kg / cm ² , and the pressure in the secondary container 31 rises above this set pressure. In this case, the release system destruction plate 58 bursts and the secondary container 3
A gaseous reaction product such as hydrogen gas in 1 passes through the release system pipe 57 and is released from the atmosphere release unit 61 to the atmosphere.

At this time, the coolant (sodium) in the secondary container 31 may move through the space between the container 31 and the roof slab 33 and reach the cylindrical body 34b of the manometer seal 34. However, the outlet of the discharge system pipe 57 is arranged on the back side of the secondary container 31 so as to be close to the inner wall of the double cylindrical gutter 34a, that is, near the peripheral wall of the secondary container 31, and the cylindrical barrel 34b. Since the large diameter portion 34d is formed in the upper portion, the swirling flow component of sodium that migrates to the manometer seal 34 side is promoted, and migration of sodium into the discharge system pipe 57 is suppressed by the principle of centrifugation.

Therefore, in the release system pipe 57, only gas products such as hydrogen gas are prevented from flowing and sodium is prevented from flowing, so that gas (reaction product) and liquid (sodium) are mixed. It is possible to eliminate the need to separately provide a cyclone separator for separation.

It should be noted that an igniter or the like is arranged in the actual atmosphere releasing portion 61, and after the hydrogen gas is burned by the igniter, water vapor is released to the atmosphere.

[0048]

As described above, according to the present invention,
It is possible to prevent the liquid from flowing in the discharge system piping of the pressure regulating mechanism that suppresses the pressure rise in the secondary container and to allow only the gas to flow, and thereby the gas (reaction product)
It is necessary to separately provide a cyclone separator for separating the liquid (sodium) and the liquid (sodium), and thus it is possible to simplify the structure of the nuclear reactor itself and the arrangement of equipment in the building.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 is an enlarged view of part A in FIG.

FIG. 3 is a cross-sectional view showing a conventional example.

FIG. 4 is an enlarged view of part B in FIG.

[Explanation of symbols]

 31 Secondary Container 32 Base Slab 33 Roof Slab 34 Manometer Seal 34a Double Cylindrical Gutter 34b Cylindrical Cylinder 34c Seal Liquid 34d Large Diameter Part 35 Primary Vessel 37 Reactor Core 51 Steam Generator 57 Emission System Piping 58 Emission System Destruction Plate 61 Atmospheric Emission Part 62 Pressure regulating mechanism

Claims (1)

[Claims] 1. A secondary container installed on a base slab for accommodating a steam generator, a primary container arranged in the secondary container for storing a core therein, and installed at an upper end opening of the base slab. Roof slab, a manometer seal provided between the roof slab and the upper opening of the secondary container, and connected to the manometer seal via a discharge system pipe to increase the pressure inside the secondary container. In a double tank reactor equipped with a pressure regulating mechanism for suppressing, a groove-shaped double cylindrical gutter connected to a peripheral edge of an upper end opening of the secondary vessel and opening upward, and the double slab from the roof slab The manometer seal is composed of a cylindrical barrel having a large diameter part that is hung down to reach the inside of the cylindrical gutter and has an enlarged diameter in the upper part, and a liquid such as molten metal injected into the double cylindrical gutter, and Pressure machine Of the discharge system is arranged so as to pass through the large diameter portion of the cylindrical body and reach an end outlet of the pipe close to the inner wall of the double cylindrical trough. Reactor.