JPH06214070A - Double tank type nuclear reactor - Google Patents

Abstract

PURPOSE:To suppress a further pressure rise even when the pressure in a secondary vessel is raised over the seal function of a manometer seal, and avoid the buckling of a primary vessel by an external pressure. CONSTITUTION:A double tank type nuclear reactor is provided with a secondary vessel 31 arranged on a base slab 32 to house a steam generator 51; a primary vessel 35 arranged in the secondary vessel 31 to house a core 37; a roof slab 33 arranged on the upper end opening part of the base slab 32; and a manometer seal 34 provided between the roof slab 33 and the upper opening part of the secondary vessel 31. Further, a communicating part 64 for allowing a core lower space 67 between the secondary vessel 31 and the base slab 32 to communicate with a core upper space 68 above the roof slab 33 is formed, and destructive plates 65a, 65b broken by a determined pressure are arranged opposite to each other in two vertical stages in the communicating part 64.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a double container tank type fast breeder reactor (double tank reactor) using a liquid metal such as sodium as a coolant, and particularly to a pressure increase in a secondary container. The present invention relates to a double tank reactor in which the primary container is prevented from buckling.

[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.

The manometer seal 4 has a groove-shaped double cylindrical gutter 4a which is connected to the outer peripheral edge of the upper end opening of the secondary container 1 and opens upward, and a double cylindrical gutter hanging from the roof slab 3 and having a lower end double cylinder gutter. It is composed of a cylindrical barrel 4b inserted into 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, and in a state where the lower end of the cylindrical body 4b is submerged in the sealing liquid 4c, a non-contact double cylindrical gutter 4a.
The space between the cylinder body 4b and the cylinder body 4b is sealed.

In the manometer seal 4 having such a structure, the radial position of the cylindrical barrel 4b reaches almost the center of the double cylindrical trough 4a so that the size thereof is optimized in the operating state of the reactor. In addition, the burial depth and axial position of the cylindrical body 4b in the seal liquid 4c are also arranged so as to reach the target point in the operating state. At the center of the inside of the secondary container 1, there is arranged a pot-shaped primary container 5 having a reduced upper end. The primary container 5 is the secondary container 1
Installed on the bottom mirror of the roof slab, and 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 container 5 while penetrating the primary system partition walls 11. The upper end of
A stand 14 provided on the upper shoulder portion 5a of the pot-shaped primary container 5 is suspended and supported by a seal ring and a bolt (not shown).

The intermediate heat exchanger 12 has 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.

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 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 as to absorb thermal expansion, and the intermediate heat exchanger 1
A secondary coolant electromagnetic pump 16 is attached to the lower end of 2, and the secondary coolant electromagnetic pump 16 sucks the secondary coolant through a through hole 17 provided at the bottom of the primary container 5. The intermediate heat exchanger 12 is fed. 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.

The upper space of the primary high temperature pool 9 of the primary container 5 and the secondary high temperature pool 19 of the secondary container 1 is a cover gas space filled with a cover gas. 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 partition 18, and each of these steam generators 21 is a roof slab. Suspended from 3. Openings are provided at positions corresponding to the pools 19 and 20 of the steam generator 21, and the high-temperature secondary coolant in the secondary high-temperature pool 19 is discharged from the upper opening to the steam generator. 21 performs heat exchange with the water which flows into the inside 21 and is sent through the water supply pipe 22, and the secondary coolant after the heat exchange is delivered to the secondary low temperature pool 20 through the opening at the bottom. It has become.

The secondary coolant flows outside a heat transfer pipe (not shown) arranged in the steam generator 21, and the 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 shield plug 6, reference numeral 25 is a telescopic cylinder for absorbing thermal expansion provided on 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 a discharge system pipe 27 is connected to the cylindrical body 4b of the manometer seal 4, and the discharge system is broken at the other end of the discharge system pipe 27 at a pressure higher than a predetermined set pressure. A breaking plate 28 is provided.
As a result, 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 bursts and the gas in the secondary container 1 causes the rupture. Open the pressure to the atmosphere and further manometer seal 4
When a pressure rise exceeding the set pressure of 1 occurs, the airtightness of the manometer seal 4 is broken, and the gas enters the space between the secondary container 1 and the base slab lining 30.

[0013]

However, in the above-mentioned conventional example, the release system rupture plate 28 is ruptured due to a pressure increase in the secondary container 1 due to a sodium-water reaction accident in the steam generator 21, for example. If the airtightness of the manometer seal 4 is broken, the pressure increase in the secondary container 1 can be temporarily suppressed, but the continuous sodium-
If gas is generated due to water reaction or the like, the pressure inside the secondary container 1 increases again, and there is a problem that the primary container 5 may buckle due to the external pressure at this time. In view of the above, the present invention makes it possible to prevent the buckling due to the external pressure of the primary container by suppressing the further pressure increase even if the pressure in the secondary container increases until it exceeds the sealing function of the manometer seal. The purpose is to provide.

[0014]

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 in a double tank reactor equipped with a roof slab installed at an upper end opening of the base slab and a manometer seal provided between the roof slab and an upper opening of the secondary container. The slab is provided with a communication part that connects the furnace lower space between the secondary container and the base slab and the furnace upper space above the roof slab, and a rupture plate that ruptures at a predetermined pressure is placed inside the communication part. It is characterized by being arranged in two stages facing each other.

[0015]

According to the present invention configured as described above, when a sodium-water reaction accident occurs in the steam generator and the pressure in the secondary container reaches a pressure exceeding the sealing function of the manometer seal, for example, Gas is introduced into the furnace lower space between the next vessel and the base slab. Then, when this gas reaches a predetermined pressure, the rupture plate provided in the communication section provided in the roof slab bursts, and this gas is released to the furnace upper space above the roof slab via the communication section, By
It is possible to suppress the pressure rise in the secondary container and avoid buckling of the primary container. Further, by disposing the rupture plates so as to face each other in the upper and lower two stages, the rupture pressure of each rupture plate is individually set, and the water-steam is generated by an accident of water-steam ejection which occurs in the upper space of the reactor, for example. It is possible to prevent the invasion of the furnace lower space between the next container and the base slab lining.

[0016]

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 reactor in the present 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 slab 32. A manometer seal 34 is provided between the upper end opening of the secondary container 31 and the roof slab 33. A cover gas space filled with a cover gas is formed above the secondary high temperature pool 49 in the secondary container 31. Further, a cover gas space filled with the cover gas is also formed above the primary high temperature pool 39 in the primary container 35 installed inside the secondary container 31.

The manometer seal 34 is, as shown in an enlarged manner in FIG. 2, provided in the outer peripheral edge of the upper end opening of the secondary container 31 and has a groove-shaped double cylindrical trough 34a which opens upward.
And the lower end is a double cylindrical gutter 34 that hangs from the roof slab 33.
It is composed of a cylindrical barrel 34b inserted in a and a seal liquid 34c injected in a double cylindrical trough 34a.
The sealing liquid 34c is formed of a molten metal such as solder or mercury, and the lower end of the cylindrical body 34b is sealed with the sealing liquid 3c.
Non-contact double cylindrical gutter 34a in a state of being submerged in 4c.
A seal is formed between the cylinder body 34b and the cylinder body 34b.

In the manometer seal 34 having such a structure, the position of the cylindrical barrel 34b in the radial direction is the double cylindrical gutter 3 so that the size thereof is optimized in the operating state of the reactor.
4a is arranged so as to reach almost the central portion, and the submersion depth and the axial position of the cylindrical body 34b in the seal liquid 34c are also arranged so as to reach the target point in the operating state. On the other hand, the furnace lower space 67 below the roof slab lower plate 33b surrounded by the secondary container 31 and the base slab lining 60, and the roof slab 3 above the roof slab 33.
3 is communicated with a furnace upper space 68 surrounded by a storage dome 63 that covers the upper part of the No. 3 by a communication section 64 provided in the roof slab 33 and communicating with the upper and lower sides. The lower breaking plate 65a and the upper breaking plate 65b to be broken are arranged in two stages of upper and lower sides with their internal pressure loading directions facing each other.

That is, the lower rupture plate 65a is arranged such that the internal pressure loading direction is from the lower side to the upper side, and the lower rupture plate 65a ruptures at a predetermined set pressure in the internal pressure loading direction and the external pressure opposite to the internal pressure loading direction. With respect to the pressure in the loading direction, the lower knife 66a disposed therebelow is contacted and bursts. On the other hand, the upper rupture plate 65b is arranged such that the internal pressure loading direction is from the upper side to the lower side, and the upper rupture plate 65b ruptures at a predetermined set pressure in the internal pressure loading direction and the pressure in the external pressure loading direction opposite to the internal pressure loading direction. In contrast, the upper knife 66b disposed above the upper knife 66b is contacted and burst.

This is because the rupture pressure of the rupture plate in the internal pressure loading direction is generally higher than the rupture pressure in the external loading direction, and by arranging in this way,
The breaking pressure of each breaking plate 65a, 65b can be freely set individually. That is, when the pressure in the furnace lower space 67 reaches the set fracture pressure of the lower rupture plate 65a, each lower rupture plate 65a that receives the internal pressure and the upper rupture plate 65b that receives the external pressure burst, whereby the lower furnace Space 67
And the furnace upper space 68 communicate with each other through the communication portion 64, and the pressure in the furnace lower space 67 can be released to the furnace upper space 68, and the pressure in the furnace upper space 68 can be set to break the upper rupture plate 65b. This is such that it will not burst unless pressure is reached.

At the center of the inside of the secondary container 31, there is arranged a pot-shaped primary container 35 having an upper end having a reduced diameter. The primary container 35 is installed on the bottom mirror of the secondary container 31 and has the upper end. 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, at corresponding positions of the primary high temperature pool 39 and the primary low temperature pool 40,
Openings for inflow and outflow of the primary coolant are provided respectively, and the high-temperature primary coolant in the primary high-temperature pool 39 flows into the intermediate heat exchanger 42 through the opening on the upper side, and inside the intermediate heat exchanger 42. The heat exchange with the secondary coolant described later will be performed. The heat-exchanged primary coolant is delivered to the primary low-temperature pool 40 through the opening at the lower end.

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 has a lower end portion. A secondary coolant electromagnetic pump 46 is attached, and this secondary coolant electromagnetic pump 46 sucks the secondary coolant through a through hole 47 provided at the bottom of the primary container 35,
The heat is fed to the intermediate heat exchanger 42. In addition,
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, a secondary system partition 48 is provided inside the secondary container 31 at a substantially middle portion in the vertical direction, and the interior of the secondary container 31 is covered by the secondary system partition 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. 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 shield plug 36 is provided with a control rod drive mechanism 54, the primary container 35 is provided with an expansion / contraction cylinder 55 for absorbing thermal expansion, and the intermediate heat exchanger 42 and the steam generator 51 are provided with intermediate portions. A bellows 56 for absorbing thermal expansion is provided. by the way,
In the steam generator 51 in the secondary container 31, 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 is changed by hydrogen gas which is the main reaction product. Rises. 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 which is destroyed by a constant pressure is interposed, 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 bursts, 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 is
After flowing into the intermediate heat exchanger 42 via 9 and performing heat exchange with the secondary coolant in the intermediate heat exchanger 42, it is sent to the primary low temperature pool 40. Then, the primary coolant in the primary low temperature pool 40 is sucked by the primary coolant electromagnetic pump 43,
Delivered to core 37 via core inlet pressure plenum 38. On the other hand, the secondary coolant that has been overheated 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 flows into the steam generator 51 to supply water. Heat exchange with the water from the tube 52 takes place. 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,
It is 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, the average temperature is, for example, about 400 ° C., and at the time of an accident, the average temperature is, 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 barrel 34b of the manometer seal 34 and that at the time of installation is relatively small. Therefore, the displacement due to the thermal expansion of the double cylindrical trough 34a connected to the upper end of the secondary container 31 is almost unchanged. The relative position with respect to the body 34b changes. 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 100 to
Since it is about 500 mmAg, for example, sealing liquid 34c
If the specific weight is about 10 g / cm ³ , the sealing property can be ensured when the liquid level difference 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, the steam generator 51 in the secondary container 31 is included.
There is a sodium-water reaction due to the heat transfer tube failure. When this sodium-water reaction occurs, the primary container 35
It is important to release the pressure in the secondary container 31 as quickly as possible so as not to impair the reliability of 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. However, if there is a large sodium-water reaction accident that exceeds the design standard, the pressure in the secondary container 31 will increase, and in this case, the manometer seal 34 is opened to suppress the pressure increase. That is, the gas in the secondary container 31 is introduced into the furnace lower space 67 between the secondary container 31 and the base slab lining 60, whereby the pressure in the secondary container 31 is reduced.

Here, the quasi-static equilibrium value due to the pressure increase in the secondary container 31 is the cylindrical body 34b of the manometer seal 34.
Of the seal liquid 34c is proportional to the submersion depth of the seal liquid 34c. For example, the specific weight of the seal liquid 34c is 10 g / c.
m ^3, if submersible depth of the cylindrical body 34b is 100 mm, the equilibrium value is about 0.2 kg / cm ^2. The manometer seal 34 is set so as to be opened only during a sodium-water reaction of a scale larger than the design standard. For example, if the value is a little smaller than about 2 kg / cm ² which is the standard of buckling (safety factor 2) in the operation state IV of the primary container 35, and the manometer seal 34 is not opened in an event within the design standard, for example, 2 kg. It is set to about / cm ² . The submersion depth in this case is about 1 m.

As a result, the manometer seal 34 is not opened under the sodium-water reaction accident within the design criteria, and therefore, there is no need to consider plant repair or the like after the manometer seal 34 is opened. For pressure control of the above, the pressure regulating mechanism 62 causes the sodium-water reaction event of small to medium / large scale within the design standard due to rupture of the release system destruction plate 58, pressure loss in the release system pipe 57, and the like. Fulfills a sufficient pressure control function.
The manometer seal 34 is not opened until a large sodium-water reaction accident that exceeds the design standard, contributes to the pressure reduction of the transiently generated quasi-steady pressure, and prevents the primary container 35 from buckling and securing the boundary function. It has been achieved.

Here, when the primary container 35 having a diameter of 10 m, a cylindrical portion length of 12 m and a plate thickness of 50 mm is used, the primary container 35 buckles due to external pressure under the condition of a temperature of about 500 ° C. The guideline for not causing pressure difference is about 5
It is about kg / cm ² . However, even if the manometer seal 34 is opened, there is still gas generation due to continuous sodium-water reaction and the like, and the secondary container 31
If the internal pressure continues to rise, this external pressure may cause the primary container 35 to buckle. To prevent this,
The following means are provided. That is, the lower breaking plate 6 provided inside the communicating portion 64 provided in the roof slab 33.
5a is the above pressure manometer seal 34 is opened, and is such as to break at a pressure of buckling load pressure below the primary container 35, for example 2.5kg / cm ² ~4kg / cm ² range .

As a result, when the pressure in the secondary container 31, and by extension, the furnace lower space 67 between the secondary container 31 and the base slab lining 60 reaches this breaking pressure, the lower breaking plate 65a and further The upper rupture plate 65b ruptures and the furnace lower space 67 and the furnace upper space 68 communicate with each other via the communication portion 64, whereby the gas in the furnace lower space 67 moves to the furnace upper space 68 and further Primary container 3 for reduced pressure
5 is prevented from buckling and the reliability of the furnace core 37 is ensured. Also, the upper breaking plate 65b
In order to prevent water or steam from entering the furnace lower space 67 from the communication portion 64 even if a large water-steam jet accident that exceeds the design standard occurs in the furnace upper space 68. The pressure is set to, for example, 2 kg / cm ² so that the upper breaking plate 65b does not burst up to the maximum pressure at the time of this water-steam jet accident.

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.

[0037]

As described above, according to the present invention,
Even if the pressure inside the secondary container becomes abnormally high and it is not possible to suppress this pressure increase only by opening the manometer seal, the pressure inside the secondary container will cause the buckling of the primary container. It is possible to prevent the temperature of the furnace core from reaching, and thus, it is possible to secure the soundness of the furnace core.

[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.

[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 35 Primary Container 37 Core 51 Steam Generator 57 Emission System Pipe 58 Emission System Destruction Plate 60 Base Slab Liner 61 Air Release Part 62 Pressure adjusting mechanism 63 Storage dome 64 Communication part 65a, 65b Breaking plate 66a, 66b Knife 67 Lower furnace space 68 Upper furnace space

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, in a dual tank reactor comprising a roof slab and a manometer seal provided between the upper opening of the secondary container, in the roof slab, the secondary container and the base slab Between the lower space of the furnace and the upper space of the furnace above the roof slab are formed with a communication part, and rupture plates that rupture under a predetermined pressure are arranged in the communication part so as to face each other in two upper and lower stages. A dual tank reactor.