JPH05107391A - Double tank nuclear reactor - Google Patents

Abstract

PURPOSE:To avoid buckling of a primary container due to external pressure by connecting a communicating piping system between the cover gas spaces of secondary and primary containers, the piping system being provided with a failure plate which crushes at predetermined pressure and a check valve which allows gas flow only from secondary to primary side. CONSTITUTION:A cover gas space is formed on a secondary high temperature pool 49 in a secondary container 31 and a primary container 35 is provided within the container 31 and a cover gas space is formed also on a primary high temperature pool 39 in the container 35. A communicating piping system 68 is provided which connects the cover gas spaces of the containers 31, 35 together via a roof slab 33 and which comprises a failure plate 64, a check valve 65 being open from a secondary system to a primary system, primary and secondary stop valves 66, 67, and piping 64. When the container 35 is 10m in diameter, 12m in the length of its cylindrical portion, 50mm in plate thickness and at a temperature of 500 deg.C, for example, the rule of thumb relating to buckling under external pressure is a differential pressure of about 5kg/cm<2>. When the set pressure of the failure plate 63 to deal with sodium- water reaction accidents is about 4kg/cm<2>, buckling of the container 35 due to external pressure can be prevented.

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 fast breeder reactor (hereinafter referred to as a double tank type reactor) which uses liquid metal as a coolant, and particularly, to prevent buckling of a primary container. Heavy tank reactor.

[0002]

2. Description of the Related Art A conventional dual tank reactor will be described with reference to FIG. In FIG. 3, reference numeral 1 is a secondary container, the secondary container 1 is installed on a base slab 2, and the upper end opening of the secondary container 1 is closed by a roof slab 3. Further, 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.

This manometer seal 4 is provided with an outer peripheral edge of an upper end opening of the secondary container 1 and has a groove-shaped double cylindrical gutter 4a and a double cylindrical gutter 4a which hangs down from the roof slab 3 and has a lower end. It comprises a cylindrical barrel 4b inserted therein and a sealing liquid 4c injected into the double cylindrical trough 4a. The sealing liquid 4c is formed of, for example, a molten metal such as solder or mercury, and the lower end of the cylindrical body 4b is submerged,
The non-contact double cylindrical gutter 4a and the cylindrical body 4b are sealed.

In the manometer seal 4 having such a configuration, 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 submersion depth and the 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 vase-shaped primary container 5 having an upper end having a reduced diameter. The primary container 5 is installed on the bottom mirror of the secondary container 1, and the upper end of the roof slab 3 is installed. Penetrates through. The upper end opening of the primary 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. In addition, at the upper end position of the core 7, the inside of the primary container 5 is set to the upper primary high temperature pool 9
A primary system partition wall 11 is provided for partitioning into the 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 partition walls 11. These upper ends are suspended and supported by a stand 14 provided on the upper shoulder portion 5a of the pot-shaped primary container 5 via a seal ring and bolts not shown.

The intermediate heat exchanger 12 is provided with primary coolant inlet / outlet openings at the corresponding positions of the primary high temperature pool 9 and the primary low temperature pool 10, respectively.
The hot primary coolant inside the intermediate heat exchanger from the upper opening
It flows into 12 and is heat-exchanged with the secondary coolant mentioned later in the intermediate heat exchanger 12. After the heat exchange, the primary coolant is delivered to the primary low temperature pool 10 through the lower opening.

The suction port of the primary coolant electromagnetic pump 13 is open in the primary low temperature pool 10, and the discharge port is directly connected to the core inlet pressure plenum 8. By this primary coolant electromagnetic pump 13, Aspirated primary cold pool
The primary coolant in 10 is sent to the core 7 via a 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. A secondary coolant electromagnetic pump 16 is attached to the lower end of the intermediate heat exchanger 12, and the secondary coolant electromagnetic pump 16 is provided with a secondary coolant via a through hole 17 provided at the bottom of the primary container 5. The coolant is sucked 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 partition wall 18 is provided at an intermediate portion in the vertical direction, and the inside of the secondary container 1 is covered by the secondary partition wall 18 and the upper shoulder portion 5a of the primary container 5 is covered. It is divided into an upper secondary high temperature pool 19 and a lower secondary low temperature pool 20 having a liquid surface above. The secondary coolant that has exchanged heat in the intermediate heat exchanger 12 is directly discharged from the upper end of the intermediate heat exchanger 12 into the secondary high temperature pool 19. The primary hot pool 9 of the primary container 5 and the upper space of the secondary hot pool 19 of the secondary container 1 form a cover gas space filled with cover gas.

A secondary partition 18 is provided inside the secondary container 1.
, A plurality of steam generators 21 are arranged at required intervals in the circumferential direction, and each steam generator 21 is suspended from the roof slab 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 stored in the steam generator 21 through the upper opening. Inflow into the water pipe 22
The heat is exchanged with the water sent through the secondary cooling medium, and the secondary coolant after the heat exchange 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. It is like this. Then, the superheated steam generated by the heat exchange in the steam generator 21 is sent to a 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. ..

In FIG. 2, reference numeral 24 is a control rod drive mechanism provided on the shielding plug 6, reference numeral 25 is an expansion / contraction cylinder provided at the upper end of the primary container 5 for absorbing thermal expansion, and reference numeral 26 is intermediate heat exchange. It is a bellows for thermal expansion absorption provided in an intermediate portion between the container 12 and the steam generator 21.

[0015]

In the conventional double tank type nuclear reactor, a manometer seal 4 is provided between the roof slab 3 and the secondary container 1. In the case of a sodium-water reaction accident in the steam generator 21, the discharge system destruction plate 28 bursts, and when a pressure rise exceeding the set pressure of the manometer seal 4 occurs, the airtightness of the manometer seal 4 is broken and the secondary Gas enters the space existing between the container 1 and the base slab lining 30.

In this case, the pressure increase in the secondary container is temporarily suppressed, but if gas is generated due to the continuous sodium-water reaction, the pressure in the secondary container increases,
There is a problem that buckling due to external pressure of the primary container 5 cannot be avoided.

The present invention has been made in order to solve the above-mentioned problems, and in the extremely large event of the sodium-water reaction,
An object of the present invention is to provide a dual tank reactor in which gas is transferred from a secondary container to a primary container to achieve pressure equalization and thereby avoiding external pressure buckling of the primary container.

[0018]

SUMMARY OF THE INVENTION The present invention is 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 a primary container on the base slab. In a dual tank reactor comprising a roof slab installed in and a manometer seal formed between the upper end opening of the secondary container, the cover gas space of the secondary container and the primary container A destruction plate for bursting the cover gas space by a predetermined pressure and a communication pipe system connected with a check valve for limiting the gas flow from the secondary container side to the primary container side are connected. And

Further, in the present invention, the roof slab and the secondary container are equipped with a discharge system for releasing the product at the time of the sodium-water reaction accident of the steam generator to the atmosphere through the discharge system piping and the destruction plate. A manometer seal is provided between the manometer seals, and the manometer seal is a groove-shaped double cylindrical gutter that is formed at a peripheral edge of an upper end opening of the secondary container and has an upward opening. It is composed of a cylindrical barrel to be inserted into the cylindrical trough and a liquid such as molten metal injected into the double cylindrical trough.

As a result, when the pressure in the secondary container exceeds the sealing function due to the liquid level difference of the manometer seal,
It is desirable to discharge the reaction product, especially hydrogen gas, into the space between the base slab lining and the secondary container.

[0021]

In the dual tank reactor according to the present invention,
A communication piping system (equalizer) is installed and connected between the secondary container cover gas space and the primary container cover gas space. When the pressure difference reaches a predetermined value, the rupture plate ruptures and the gas pressure is equalized through the communication piping system. Therefore, even in the ultimate sodium-water reaction accident, the external pressure buckling of the primary container can be avoided. In addition, the sodium-water reaction release system functions from a relatively small scale, and by discharging the reaction product to the outside, it is possible to suppress the pressure increase in the secondary container.

In the case of a larger event, by opening the manometer seal, the space between the base slab lining and the secondary container can be utilized to enhance the pressure suppressing effect. It is possible to provide a double tank reactor that does not impair the reliability of the primary vessel and the core regardless of the magnitude of the sodium-water reaction accident.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of a dual tank reactor according to the present invention will be described with reference to FIGS. Note that FIG. 2 is a vertical cross-sectional view showing an enlarged part A of FIG. FIG. 1 shows an example of a dual tank reactor according to the present invention.
Reference numeral 31 is a secondary container, and this secondary container 31 is installed on a base slab 32, and a roof slab 33 is installed at the upper end opening of the base slab 32. A manometer seal 34 is formed 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 on the secondary high temperature pool in the secondary container 31.
A primary container 35 is installed in the secondary container 31 as described later. A cover gas space filled with a cover gas is formed on the primary high temperature pool 39 in the primary container 35.

A communication pipe system (equalizer) 68 for connecting the cover gas space of the secondary container 31 and the cover gas space of the primary container 35 via the roof slab 33 is installed. This communication piping system 68 includes a breaking plate 63, a check valve 65 that opens from the secondary system to the primary system, a primary system side stop valve 66, a secondary system side stop valve 67, and a pipe 64 that connects them. It consists of

As shown in the enlarged view of FIG. 2, the manometer seal 34 has a groove-shaped double cylindrical trough 34a provided on the outer peripheral edge of the upper end opening of the secondary container 31 and opening upward, and a roof slab 33. It is provided with a cylindrical trough 34b having a lower end which is inserted into the double cylindrical trough 34a and a sealing liquid 34c which is injected into the double cylindrical trough 34a. The sealing liquid 34c is formed of, for example, a molten metal such as solder or mercury, and the cylindrical body 34b.
With the lower end of the cylinder submerged, the non-contact double cylindrical trough 34a and the cylindrical barrel 34b are sealed.

Manometer seal having such a configuration
34 is arranged so that the radial position of the cylindrical barrel 34b reaches approximately the center of the double cylindrical trough 34a so that the size thereof is optimized in the operating state of the nuclear reactor, and the seal of the cylindrical barrel 34b is arranged. The submersion depth in the liquid 34c and the axial position are also arranged so as to reach the target point in the operating state.

In 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 the upper end is a roof slab. Penetrates 33. The upper end opening of the primary container 35 is a shield plug suspended from the roof slab 33.
Blocked by 36.

A core 37 is arranged in the center of the primary container 35, and the core 37 is installed at the bottom of the primary container 35 via a core inlet pressure plenum 38. In addition, at the upper end position of the core 37, the inside of the primary vessel 35 is set to the upper primary high temperature pool 39.
A primary system partition wall 41 is provided to divide into a lower primary low temperature pool 40 and a lower primary low temperature pool 40.

A plurality of intermediate heat exchangers 42 and primary coolant electromagnetic pumps 43 are arranged at required intervals in the circumferential direction at the outer peripheral position of the core 37 in the primary vessel 35 in a state of penetrating the primary partition wall 41. As shown in FIG. 1, the upper end of the above is suspended and supported by a stand 44 provided on the upper shoulder portion 35a of the pot-shaped primary container 35 via a seal ring and bolts not shown.

The intermediate heat exchanger 42 is provided with openings for inflow and outflow of the primary coolant at corresponding positions of the primary high temperature pool 39 and the primary low temperature pool 40, respectively. Primary high temperature pool 39
The hot primary coolant inside the intermediate heat exchanger from the upper opening
It flows into the heat exchanger 42 and exchanges heat with the secondary coolant, which will be described later, in the intermediate heat exchanger 42. Then, the primary coolant after the heat exchange is delivered to the primary low temperature pool 40 through the lower opening.

The suction port of the primary coolant electromagnetic pump 43 is open to the primary low temperature pool 40, and the discharge port is directly connected to the core inlet pressure plenum 38. Aspirated primary cold pool
The primary coolant in 40 is routed to the core 37 via the core inlet pressure plenum 38.

Bellows 45 are incorporated in the lower ends of the shells of the primary coolant electromagnetic pump 43 and the intermediate heat exchanger 42, respectively, so that thermal expansion can be absorbed. A secondary coolant electromagnetic pump 46 is attached to the lower end of the intermediate heat exchanger 42. The secondary coolant electromagnetic pump 46 sucks the secondary coolant through a through hole 47 provided at the bottom of the primary container 35 and sends it to the intermediate heat exchanger 42. In this intermediate heat exchanger 42, 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 31, a secondary partition wall 48 is provided at an intermediate portion in the vertical direction. It is divided into an upper secondary high temperature pool 49 having a liquid surface above and a lower secondary low temperature pool 50. The secondary coolant that has exchanged heat 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, there is a secondary system partition wall 48.
A plurality of steam generators 51 are arranged in the circumferential direction at required intervals in a state of penetrating through the steam generators 51. Each steam generator 51 is suspended from the roof slab 33. The steam generator 51 has openings at positions corresponding to the pools 49, 50, respectively. The high-temperature secondary coolant in the secondary high-temperature pool 49 flows into the steam generator 51 through the upper opening, and the water supply pipe 52
The heat is exchanged with the water sent through the secondary coolant, and the secondary coolant after the heat exchange is delivered to the secondary low temperature pool 50 through the opening at the bottom.

This secondary coolant flows outside a heat transfer pipe (not shown) arranged in the steam generator 51, and water from the water supply pipe 52 flows inside the heat transfer pipe. It has become. Then, the superheated steam generated by the heat exchange in the steam generator 51 together with the water supply pipe 52
It is adapted to be sent to a steam turbine (not shown) via a superheated steam pipe 53 provided at the top of the.

The shielding plug 36 is provided with a control rod drive mechanism 54, and the primary container 35 is provided with an expansion / contraction cylinder 55 for absorbing thermal expansion at the upper end thereof. In addition, the intermediate heat exchanger
A bellows 56 for absorbing thermal expansion is provided between the steam generator 51 and the steam generator 51.

By the way, when a sodium-water reaction accident occurs in the steam generator 51 in the secondary container 31, it is surrounded by the secondary container 31 and the roof slab 33 by hydrogen gas which is a main reaction product thereof. Since the pressure in the internal space rises, it is necessary to avoid this.

Therefore, in the present embodiment, as shown in FIG. 1, a pressure adjusting mechanism 62 including a discharge system pipe 57, a discharge system destruction plate 58 that is destroyed by a constant pressure, and a cyclone separator (not shown) is provided in the manometer seal 34, for example. It is installed on the cylindrical body 34b so that the hydrogen gas can be released to the atmosphere 61.

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, exchanges heat with the secondary coolant in the intermediate heat exchanger 42, and then is sent to the primary low temperature pool 40. ..
The primary coolant in the primary low-temperature pool 40 is sucked by the primary coolant electromagnetic pump 43, and the core is introduced through the core inlet pressure plenum 38.
Sent to 37.

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 flows into the steam generator 51. Heat is exchanged with the water from the water supply pipe 52. The superheated steam generated by this heat exchange is sent to a steam turbine (not shown) via the superheated steam pipe 53. Further, 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 passes through the through hole 47, is sucked by the secondary coolant electromagnetic pump 46, and is sent to the intermediate heat exchanger 42.

By the way, since the secondary container 31 during operation of the nuclear reactor is overheated by the high temperature secondary coolant, the average temperature is about 400 ° C.
It can be as high as ℃. Then, the thermal expansion amount of the secondary container 31 in the axial direction is 100 to 200 mm, and the thermal expansion amount in the radial direction is 30 to 60 mm due to the temperature difference from the time of installation.

In the manometer seal 34, the cylindrical body 34b
Has a relatively small temperature difference from that at the time of installation. Therefore, the displacement of the double cylindrical gutter 34a at the upper end of the secondary container 31 due to thermal expansion almost directly changes the relative position with respect to the cylindrical body 34b. However, if the amount of thermal expansion is the same as described above, the double cylindrical gutter
By properly setting the size of 34a, it can be sufficiently absorbed.

Further, the secondary container 31 in a normal operating state
The pressure of the inert gas (argon gas, etc.) inside is 100 to 500
Since it is about mmAq, for example, the specific weight of the seal liquid 34c is
If it is about 10 g / cm ³ , the liquid level difference between the inner and outer surfaces is 10
The sealing property can be secured at ~ 50 mm.

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

For example, when the diameter of the primary container 35 is 10 m, the length of the cylindrical portion is 12 m, the plate thickness is 50 mm, and the temperature is 500 ° C., the standard for external pressure buckling is about 5 kg / cm ² differential pressure. (If the safety factor is 2, it will be about 2.5 kg / cm ^2. ) In this case, the set pressure (differential pressure) of the breaking plate 63 installed in the communication piping system (equalizer) 68 corresponding to the ultimate sodium-water reaction accident is 4 kg /
By setting it to about ^cm 2, it is possible to prevent buckling of the primary container 35 due to the external pressure.

Further, the hydrogen gas is transferred from the secondary system to the primary system, but its amount is small compared to the amount of primary sodium,
The dissolution in sodium is sufficiently slow, and the melting point of the compound NaH with Na is 150 ° C or less, so there is no problem with solidification in the core.

It is also possible to suppress the pressure increase due to the opening of the manometer seal 34. That is, the decompression effect can be expected by utilizing the space volume existing between the base slab lining 60 and the secondary container 31.

Here, the quasi-static equilibrium value due to the pressure increase in the secondary container 31 is proportional to the submersion depth of the cylindrical barrel 34b of the manometer seal 34 in the seal liquid 34c. specific weight of the liquid 34c is 10 g / cm ^3, a cylindrical cylinder 34b
If the submersion depth is 100 mm, the equilibrium value will be 0.2 kg / cm ³ .

The manometer seal 34 is set so as to be opened only during a sodium-water reaction of a larger scale than the design standard. For example, it is possible to set the value so that the manometer seal 34 will not be opened if the value is a little smaller than about 2.5 kg / cm ³ which is the standard for buckling (safety factor 2) in the operating condition IV of the primary container 35 and within the design standard. It is possible. For example, about 2 kg / cm ² . In this case, the submersion depth is about 1 m.

However, the quasi-steady pressure rise value is determined by appropriately utilizing the pressure loss depending on the inertial force of the seal liquid 34c and the flow passage area in the conduction path of hydrogen gas which is a sodium-water reaction product. Buckling guideline for the primary container 35 (operating state IV)
It can be suppressed to about 2.5 kg / cm ² . In addition, after the manometer seal 34 is opened, a large pressure reducing effect can be expected due to the size of the space volume existing between the base slab lining 60 and the secondary container 31.

Pressure setting of the release system destruction plate 58 (for example,
When the pressure in the secondary container 31 rises above 0.5 kg / cm ² ), the release system destruction plate 58 is destroyed and the pressure by the gas is released to the atmosphere 61. In an actual system, when the hydrogen gas is released to the atmosphere 61, the hydrogen gas is burned by an igniter or the like and released as water vapor.

According to this embodiment described above, since the communication pipe system (equalizer) is formed in the cover gas space of the primary container and the secondary container, the buckling of the primary container is caused even in the ultimate sodium-water reaction accident. Can be prevented and the reliability of the core can be secured. Further, a manometer seal composed of a double cylindrical trough, a cylindrical barrel and a sealing liquid is formed between the roof slab and the upper end opening of the secondary container.

This manometer seal is set so as not to be opened under the sodium-water reaction event within the design standard, and it is not necessary to consider plant repair after the manometer seal is opened.

On the other hand, a reaction product release system is formed as an original pressure suppressor for sodium-water reaction, and the design standard is satisfied due to the set pressure of the release system destruction plate and the pressure loss of the release system piping path. It has a sufficient pressure suppression function for the relatively small to medium to large scale sodium water reaction events.

Also, the manometer seal is opened only when a large sodium-water reaction event exceeds the design standard, and it contributes to the pressure reduction of the transiently generated quasi-steady pressure. In this case, prevention of buckling of the primary container and securing of the boundary function are achieved.

Unexpectedly, in the ultimate sodium-water reaction event, in addition to opening the manometer seal, equalizing the pressure of the communication piping system (equalizer) formed between the primary container and the secondary container. Due to the effect, buckling of the primary container can be prevented. However, in this case, the cover gas boundary is in communication, and hydrogen gas is transferred to sodium through the primary system cover gas space, but in this case as well, the core is not damaged.

[0058]

According to the present invention, even if the ultimate reaction between sodium and water occurs in a double tank reactor, it is possible to avoid buckling due to the external pressure of the primary vessel.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a double tank reactor according to the present invention.

FIG. 2 is an enlarged vertical sectional view showing an “A” portion in FIG.

FIG. 3 is a cross-sectional view showing a conventional dual tank reactor.

[Explanation of symbols]

31 ... Secondary container, 32 ... Base slab, 33 ... Roof slab,
34 ... Manometer seal, 35 ... Primary container, 36 ... Shield plug, 37 ... Core, 38 ... Core inlet pressure plenum, 39 ... Primary high temperature pool, 40 ... Primary low temperature pool, 41 ... Primary partition wall, 42 ...
Intermediate heat exchanger, 43 ... Primary coolant electromagnetic pump, 44 ... Stand, 45 ... Bellows, 46 ... Secondary coolant electromagnetic pump, 47 ... Through hole, 48 ... Secondary partition, 49 ... Secondary high temperature pool, 50 … Secondary cold pool, 51… Steam generator, 52… Water supply pipe, 53… Superheated steam pipe, 54… Control rod drive mechanism, 55… Telescopic cylinder, 56… Bellows, 57… Ejection system piping, 58… Emission system destruction Board, 59 ... Missing number, 60
… Base slab lining, 61… Open to the atmosphere, 62… Pressure regulation mechanism, 63
… Breaking plate, 64… Piping, 65… Check valve, 66… Stop valve on primary system side,
67… Secondary system side stop valve, 68… Communication piping system.

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 a roof slab installed on the base slab. In a double-tank reactor equipped with a manometer seal formed between the upper end opening of the secondary container, the cover gas space of the secondary container and the cover gas space of the primary container are predetermined. A double tank type atom characterized in that it is connected by a communication pipe system to which a check valve or the like that limits the flow of gas and a rupture plate that bursts by pressure from the secondary container side to the primary container side is connected. Furnace.