JP2000180579A - Reactor containment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a ferroconcrete reactor containment capable of reducing construction man-day and material weight of the body of the reactor containment. SOLUTION: In a welded assembly of liner plates 19a, 19b and 19c and liner anchors 20a, 20b and 20c of reactor containment, among the liner anchor pitch A5 of a top slab and the liner anchor pitch B8 of drywell side walls of the reactor containment and the liner anchor pitch C11 of the suppression chamber side wall of side walls of the reactor containment, C11 is set in a larger pitch than A5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a nuclear reactor containment vessel, and more particularly, to the setting of a liner anchor as an inner lining of the nuclear reactor containment vessel.

[0002]

2. Description of the Related Art In a nuclear power plant, as shown in FIG. 4, a reactor pressure vessel is used so that a radioactive substance leaked from a reactor core to a reactor containment vessel 14 in the event of a primary reactor failure is released. The primary storage facility is provided in the reactor building 13.

The containment vessel 14 of a boiling water reactor is
All are of the pressure suppression type, and are composed of a dry well zone and a pressure suppression chamber zone (suppression chamber zone).

[0004] The dry well 15 comprises a reactor pressure vessel 1,
Equipment that belongs to the reactor pressure boundary such as recirculation system equipment and piping, steam piping, etc., the base 18 of the cylindrical reactor pressure vessel main body, and the internal structure of the containment vessel for shielding, etc. It is designed to secure the necessary space for piping routes or maintenance and inspection.

Further, the suppression chamber 16 holds pool water, and when the pressure inside the dry well 15 rises,
The high-temperature and high-pressure steam in the dry well 15 is pushed into the pool water through a vent pipe, and the steam is cooled by the pool water.
A non-condensable gas pushed into the suppression chamber 16 is stored in a free space of the suppression chamber 16. The dry well 15 and the suppression chamber 16 are separated by a diaphragm floor 6 made of reinforced concrete, and a vent pipe is provided as a means for flowing a fluid such as steam between the dry well 15 and the suppression chamber 16.

[0006] The reactor containment vessel 14 is composed of such zones as the dry well 15 and the suppression chamber 16.

The dry well 15 includes a dry well side wall 7 (shell wall), a top slab 4 (ceiling wall), a diaphragm floor 6, a dry well upper mirror 17, which is a freestanding steel part, and a reactor pressure vessel body. Of the base 18 and the bottom surface 9a of the storage container.

Among them, the top slab 4 has a suitable strength as the spent fuel pool 2 located above the reactor pressure vessel 1 and the containment vessel 14 and the pool bottom wall of the steam dryer / gas separator pit 3. It is an expected strength member.

The suppression chamber 16 is surrounded by the outer peripheral surface of the base 18 of the reactor pressure vessel main body, the suppression chamber side wall 10, the diaphragm floor 6, and the containment vessel bottom surface 9.

[0010] The skeleton of a reinforced concrete reactor containment vessel (hereinafter referred to as RCCV) has the structure and function as described above, and supports the following loads.

The top slab 4 and the drywell side wall 7 (shell) constituting the drywell 15 are a reinforced concrete frame body lined with a steel liner plate via a liner anchor.

The reinforced concrete portion of the top slab 4 and the drywell side wall 7 has functions of pressure resistance, earthquake resistance and shielding, and a liner plate lined with the reinforced concrete portion by a liner anchor has a function of preventing leakage.

Further, due to the high temperature of the reactor pressure vessel 1 in the containment vessel 14, an excessive thermal load is applied to the liner anchor due to a temperature difference and a thermal expansion difference between the reinforced concrete and the steel liner plate.

Further, the liner plate and the liner anchor are not required to have a function as a pressure-resistant and seismic strength member of the reinforced concrete containment body, but since the liner plate and the liner anchor are used as a concrete casting frame when constructing the containment vessel, the liner plate and the liner anchor are required. It is designed to support the installed pressure.

Furthermore, the design is such that the pressure resistance to the internal pressure load applied to the initial strain portion between the liner anchor supports when the liner plate is installed can be satisfied.

The above-described reinforced concrete, liner plate, and liner anchor structure have the same structure in the suppression chamber side wall 10.

The liner plate and liner anchor lined with reinforced concrete are provided with a suppression chamber side wall 10 from the bottom surface 9 of the containment vessel to a lower end surface of the diaphragm floor, a drywell side wall 7 from an upper end surface of the diaphragm floor 6 to a lower end surface of the top slab 4, And it is provided on the ceiling surface from the side wall end of the lower end surface of the top slab 4 toward the center of the reactor containment vessel.

The liner anchors of the drywell side wall 7 and the suppression chamber side wall 10 are provided at equal pitches in the radial direction on the outer surface of the liner plate of the containment cylinder. The liner anchors of the top slab 4 are provided horizontally at equal pitches in the chord direction of the circular cross section on the ceiling surface of the top slab 4.

As the liner anchor pitch, a pitch having sufficient strength against the above-described driving pressure and temperature (heat) load is selected and set.

Further, in the prior art, the liner anchor pitches of the drywell side wall 7, the suppression chamber side wall 10, and the top slab 4 wall have the same pitch confirmed by experiments and the like. To make the pitch the same, a pitch adopted for a part under the strictest use conditions is selected.

The pitch of the liner anchor of the liner plate of the containment vessel is disclosed in Japanese Patent Application Laid-Open No. 8-22027.
As disclosed in Japanese Patent Publication No. 3, the installation interval (liner anchor pitch) of the liner anchor structure of the reinforced concrete frame is set to be an integral multiple of the interval between the reinforcing bar and the reinforcing bar of the frame. Exemplifies a liner anchor pitch of 570 mm.

[0022]

In the prior art, the liner anchor pitch of the liner plate is set to be smaller than that of each part, irrespective of the difference in load and structural characteristics of the skeleton of each part of the reactor containment vessel. Since the pitches are equal pitches under relatively harsh conditions of use, it has been difficult to reduce the amount of construction of the containment vessel and the number of construction steps.

Accordingly, an object of the present invention is to achieve a reduction in the amount of construction of the containment vessel and a reduction in the number of construction steps.

[0024]

To achieve the object of the present invention, the basic constituent elements are a liner anchor pitch A of a top slab of a containment vessel and a liner anchor of a dry well side wall of the containment vessel. A reactor containment vessel set at a pitch such that the liner anchor pitch C is larger than the liner anchor pitch A among a pitch B and a liner anchor pitch C on a suppression chamber side wall of the reactor containment vessel, Considering the liner anchor structure and the liner anchor pitch in consideration of the continuity in construction, the liner plate and liner anchor structure of the reactor containment vessel contain a suppression chamber side wall from the bottom of the containment vessel to the lower end of the diaphragm floor, and a diaphragm. From floor upper end to top slab lower end (ceiling surface)
Up to the drywell side wall and top slab, and each of these structural sections clearly has different design conditions and operating conditions, and liner anchors according to the operating conditions of each structural section. By setting the pitch of each line for each structural section, the liner anchor pitch with few excess and deficiency can be used, and the amount of the liner anchor and the number of steps for constructing the liner anchor can be reduced as much as possible.

[0025]

DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIG. 4, a reactor building 14 of a nuclear power plant has a reactor containment vessel 14 for preventing radioactive materials leaked from a reactor core from being released outside in the event of a primary reactor damage accident. Is provided as a primary containment facility for the reactor pressure vessel 1.

The containment vessel 14 of the boiling water reactor is
Drywell 15 zone and suppression chamber 1
It consists of six zones.

The dry well 15 includes a cylindrical dry well side wall 7 (shell wall), a top slab 4 (ceiling wall), a diaphragm floor 6, a dry well upper mirror 17, which is a self-supporting steel part, and a reactor pressure. The container is surrounded by the inner peripheral surface of the cylindrical base 18 of the container body and the bottom surface 9a of the container.

The top slab 4 and the drywell side wall 7 (shell) constituting the drywell 15 are a reinforced concrete body having steel liner plates 19a and 19b lined through T-shaped liner anchors 20a and 20b. .

The liner anchors 20a and 20b and the liner plates 19a and 19b are welded to each other at a portion indicated by a welding line 12 to form a welded assembly.

In particular, the top slab 4 is expected to have a corresponding wall strength as a pool bottom wall of the spent fuel pool 2 and the steam dryer / gas separator pit 3 located above the reactor pressure vessel 1 and the containment vessel 14. High strength member.

On the other hand, the suppression chamber 16 is surrounded by the outer peripheral surface of the foundation 18 of the reactor pressure vessel main body, the cylindrical suppression chamber side wall 10, the diaphragm floor 6 and the containment bottom 9.

Like the drywell side wall 7, the suppression chamber side wall 10 constituting the suppression chamber 16 is a reinforced concrete frame body lined with a steel liner plate 19c via a liner anchor 20c. The liner anchor 20c and the liner plate 19
c is also a welded assembly welded at the welding line 12.

The dry well 15 includes the reactor pressure vessel 1, equipment belonging to the reactor pressure boundary such as recirculation system equipment / piping and steam piping, the base 18 of the cylindrical reactor pressure vessel main body, and the like. Is designed to enclose the internal structure of the containment vessel for shielding, and to secure the safety and the space required for the piping route or maintenance and inspection.

Further, the suppression chamber 16 holds pool water, and when the pressure in the dry well 15 rises,
The high-temperature and high-pressure steam in the dry well 15 is pushed into the pool water through a vent pipe, and the steam is cooled by the pool water.
A non-condensable gas pushed into the suppression chamber 16 is stored in a free space of the suppression chamber 16. The dry well 15 and the suppression chamber 16 are separated by a diaphragm floor 6 made of reinforced concrete, and a vent pipe is provided as a means for flowing a fluid such as steam between the dry well 15 and the suppression chamber 16.

The skeleton of a reinforced concrete reactor containment vessel (hereinafter referred to as RCCV) has the structure and function as described above, and the operating conditions for supporting the following loads are set. .

The top slab 4, the drywell side wall 7, and the suppression chamber side wall 10 are constructed such that the reinforced concrete portion has functions of pressure resistance, earthquake resistance and shielding, and the liner anchors 20a, 20b, 20c are embedded in the reinforced concrete. The reinforced concrete surface is lined with liner plates 19a, 19b, 19c to prevent leakage.

Further, due to the high temperature of the reactor pressure vessel 1 in the containment vessel 14, an excessive thermal load is applied to the liner anchor due to the temperature difference and the thermal expansion difference between the reinforced concrete and the steel liner plate.

The liner plates 19a, 19b, 1
The 9c and the liner anchors 20a, 20b, 20c are not required to function as pressure-resistant and seismic strength members of the reinforced concrete containment skeleton, but since they are used as concrete casting frames when constructing a reactor containment, It is designed to support the casting pressure.

Further, the design is such that the pressure resistance against the internal pressure load applied to the initial strain portion between the liner anchor supports when the liner plate is installed is satisfied.

Further, the welding assembly of the liner plate 19c and the liner anchor 20c lined with reinforced concrete is provided on the suppression chamber side wall 1 in the region c from the vicinity of the bottom surface 9 of the containment vessel to the vicinity of the lower end surface of the diaphragm floor 6.
0, liner plate 19b and liner anchor 2
0b is applied to the drywell side wall 7 in a region b from the vicinity of the upper end face of the diaphragm floor 6 to the vicinity of the lower end face of the top slab 4, and the wall end of the lower end face of the top slab 4 faces the center of the containment vessel. A welded assembly of the liner plate 19a and the liner anchor 20a is installed on the ceiling surface of the area a.

The liner anchors 20b, 20c of the drywell side wall 7 and the suppression chamber side wall 10 are arranged at an arbitrary pitch in the circumferential direction of the outer peripheral surfaces of the liner plates 19b, 19c of the containment cylinder.

Further, the liner anchor 2 of the top slab 4 parts
0 a are provided horizontally at an arbitrary pitch in the chord direction of the circular cross section on the ceiling surface of the top slab 4.

Each of these liner anchors 20a, 20b, 2
The pitch of 0c is set by selecting a pitch having sufficient strength against the above-described driving pressure and temperature (heat) load. In each embodiment of the present invention, the pitch of each part of the reactor containment vessel is set. The pitch is relatively changed according to the construction and use conditions.

That is, a first embodiment in which the pitch is relatively changed is shown in FIG. In FIG. 1, the pitch of the liner anchor 20a of the top slab 4 which is the bottom wall of the spent fuel pool 2 and the steam dryer / gas separator pit 3 located above the reactor pressure vessel 1 is represented by a liner anchor pitch A5. Of the liner anchor pitches confirmed by experiment and theory, a pitch used under severe conditions is used, and a liner anchor pitch structure capable of withstanding the severe concrete placing pressure of the fuel pool 2 and the pit 3 is used.

As a result, the liner plate 19a and the liner anchor 20a become horizontal, so that they can withstand the strength even under construction conditions in which the load of reinforced concrete is largely applied in the direction of gravity.

The liner anchor 2 of the liner plate 19b employed between the region b from the vicinity of the lower surface of the top slab 4 (the top surface of the containment vessel) to the vicinity of the upper surface of the diaphragm floor 6
The pitch 0b, that is, the liner anchor pitch B8 of the drywell side wall 7 uses a wider liner anchor pitch B than the liner anchor pitch A5 of the top slab 4.

The liner anchor 20b is
Since it is not horizontal but vertical with the liner plate 19b as shown in FIG. 7A, the reinforced concrete placing load for constructing the drywell side wall 7 does not need to be large.

However, in the event of an accident, the heat energy in the reactor pressure vessel 1 is released as high-temperature and high-pressure steam into the dry well 15, and higher heat is applied to the dry well side wall 7 than to the suppression chamber side wall 10.

Under the use conditions at the time of such an accident, the liner plate 19b receives a larger heat (temperature) load than the liner plate 19c receives.

In consideration of such use conditions and construction conditions, the liner anchor 20b is wider than the liner anchor pitch A5 and has a liner anchor pitch C1 described later.
A liner anchor pitch B narrower than 1 is set.

The suppression chamber 16 has a function of receiving high-temperature and high-pressure steam in a dry well through a vent pipe and condensing it with pool water to make low-temperature and low-pressure at the time of an accident. Well 15
More moderate than.

Therefore, the liner anchor pitch C11 of the liner anchor 20c of the suppression chamber side wall 10 in the region c from the vicinity of the lower surface of the diaphragm floor 6 to the vicinity of the storage container bottom surface 9 is wider than the liner anchor pitch B8 of the drywell side wall 7. C is used.

In the first embodiment, the liner anchor pitch is
The pitch width is varied so that the liner anchor pitch A of the top slab 4 <the liner anchor pitch B of the drywell side wall 7 <the liner anchor pitch C of the suppression chamber side wall 10.

In the first embodiment, the liner anchor pitch A is set to be the narrowest, paying attention to the top slab 4 where the driving pressure is stricter than the other parts, and the other is the liner anchor pitch B and the liner anchor pitch C. With a wide pitch,
Liner anchors 20a, 20 for all areas a, b, c
While the pitches of b and 20c are set to the liner anchor pitch A, the physical quantities of the liner anchors 20b and 20c and the total length of the welding line 12 are reduced, and the amount of construction and the number of construction steps can be reduced.

FIG. 2 shows a second embodiment in which the pitch is relatively changed.
Is shown in FIG. 2 shows an application example of the present invention having a liner anchor pitch according to a unique use condition of a plant.

The second embodiment corresponds to a case where the thermal (temperature) conditions in the dry well 15 at the time of an accident are severer than the first embodiment.

As a countermeasure, the liner anchor pitch A of the top slab 4 ≦ the liner anchor pitch B of the drywell side wall 7 <the liner anchor pitch C of the suppression chamber side wall 10.

In FIG. 2, focusing on the liner anchor pitch of the dry well 15 including the top slab 4 and the dry well side wall 7 where the concrete placing load condition and the temperature condition are severe during construction, the liner anchor pitch is shown. B
Is a narrow pitch equivalent to the liner anchor pitch A, and the liner anchor pitch C is rationalized as a wider pitch. Since the liner anchor pitch C does not have to be made too narrow to be enough to cope with concrete placing load in a horizontal position like the liner anchor pitch A, the thermal condition in the dry well 15 is lower than that of the first embodiment. Can be handled even if it is severe, and the liner anchor 2
0c and the total length of the welding line 12 can be reduced, so that the amount of construction and the number of construction work steps can be reduced.

A third embodiment in which the pitch is relatively changed is shown in FIG.
Is shown in FIG. 3 shows an example having a liner anchor pitch corresponding to a unique use condition of a plant.

The third embodiment corresponds to a case where the thermal (temperature) conditions in the dry well 15 at the time of an accident are milder than those in the first embodiment.

As a countermeasure, the liner anchor pitch A of the top slab 4 <the liner anchor pitch B of the drywell side wall 7 = the liner anchor pitch C of the suppression chamber side wall 10.

In this way, the flexibility of the rational containment frame design having the liner anchor pitch according to the unique use conditions of the plant is improved.

The third embodiment shown in FIG. 3 is similar to the first embodiment in that the liner anchor 20a has a liner anchor 20a and a liner plate 19a that can withstand the concrete placing load of the reinforced concrete of the top slab 4 even when the liner anchor 20a and the liner plate 19a are horizontal. Anchor pitch A is replaced with other liner anchors 20b, 2
The pitch is narrower than the liner anchor pitches B and C of 0c.

On the other hand, since the thermal (temperature) condition at the time of the accident of the dry well 15 is gentler than that of the first embodiment, the liner anchor pitch B of the liner anchor 20b of the dry well side wall 7 is the same as that of the first embodiment. Set wider than liner anchor pitch B.

Then, the liner anchor pitch C of the liner anchor 20c on the suppression chamber side wall 10 is made equal to the liner anchor pitch B in FIG.

As described above, when the liner anchor pitch C is matched with the liner anchor pitch B, the thermal condition of the dry well 15 hardly exceeds the thermal condition in the suppression chamber 16.
There is no problem in setting the liner anchor pitch C of the zero liner anchor 20c to the same pitch in accordance with the liner anchor pitch B.

In addition, all the liner anchors 20a, 20
The liner anchor pitches of the liner anchors 2 and 2c are different from those of unifying the liner anchor pitches in accordance with the liner anchor pitch a.
Ob, 20c and the total length of the welding line 12 can be reduced, and the amount of construction and the number of construction work steps can be reduced.

Since the liner anchor pitch B and the liner anchor pitch C of each liner anchor 20b, 20c are the same, the welded assembly of the liner anchor 20b and the liner plate 19b in the region b and the liner anchor 20 in the region c
c and a welded assembly of the liner plate 19c have almost the same appearance.

For this reason, the parts that can be shared for the design and manufacturing of the respective welded assemblies are increased, which can contribute to the rationalization of the design and manufacturing, and the cost is reduced by increasing the common design and common manufacturing parts. The effect is also exhibited.

According to the embodiment of the present invention, the following effects can be obtained.

The liner anchor pitch according to the use condition of each structural part of the reinforced concrete containment container is selected, and the pitch is made different for each structural part, so that the liner anchor pitch by the conventional dominant part is uniform. Compared to the containment vessel liner anchor structure, the amount of liner anchor was reduced, the number of welding lines and work was reduced, and the number of installation steps was reduced.

Further, by combining different liner anchor pitches according to the unique use conditions of the plant, the flexibility of the design of the reinforced concrete containment frame can be improved, the excess design can be reduced, and the cost suitable for customer needs can be reduced. Performance can be provided.

[0073]

According to the first aspect of the present invention, the pitch of the liner anchor of the containment vessel is relatively changed in accordance with the building conditions and use conditions of each structural part. It is possible to reduce the amount of building, the number of man-hours for building work, and the process.

According to the invention of claim 2, in addition to the effect of the invention of claim 1, each liner anchor pitch A, B, C
Are set so as to be different from each other, so that each liner anchor pitch A, B, C can be appropriately adjusted without any excess or shortage in accordance with the different building conditions and use conditions in each structural part.
Can be set.

According to the third aspect of the invention, in addition to the effects of the first aspect of the invention, the use conditions such as the thermal (temperature) conditions of the dry well of the containment vessel can be handled by the first aspect of the invention. The effect of being able to respond even more strictly than the one obtained is obtained.

According to the fourth aspect of the present invention, if the use conditions such as the thermal (temperature) condition of the dry well of the containment vessel are more moderate than those which can be dealt with by the first aspect of the present invention, an excessive The effect of avoiding the input of a large amount of building and work,
The design and manufacturing of the welded assembly between the liner anchor and the liner plate on the drywell side wall and the welded assembly between the liner anchor and the liner plate on the suppression chamber side wall have been increased, contributing to streamlining design and manufacturing. As a result, the number of common designs and common manufacturing parts increases, and the economic effect of lower cost is also exhibited.

[Brief description of the drawings]

FIG. 1 is a bird's-eye view of a part of a welded assembly of a liner anchor and a liner plate of a reinforced concrete reactor containment vessel according to a first embodiment of the present invention.

FIG. 2 is a bird's-eye view of a part of a welded assembly of a liner anchor and a liner plate of a reinforced concrete reactor containment vessel according to a second embodiment of the present invention.

FIG. 3 is a bird's-eye view of a portion of a liner anchor and liner plate welding assembly of a reinforced concrete containment vessel according to a third embodiment of the present invention.

FIG. 4 is a longitudinal sectional view of a reactor building and a reinforced concrete containment vessel of a nuclear power plant.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Reactor pressure vessel, 2 ... Spent fuel pool, 3 ... Steam dryer / gas separation pit, 4 ... Top slab, 5 ... Liner anchor pitch A, 6 ... Diaphragm floor, 7 ... Dry well side wall, 8 ... Liner Anchor pitch B, 10: suppression chamber side wall, 11: liner anchor pitch C, 12: welding line, 13: reactor building, 14: reactor containment vessel, 15: dry well, 16: suppression chamber, 19a, 19b, 19c … Liner plate, 2
0a, 20b, 20c ... liner anchors.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Shigeru Nanba 3-1-1, Sachimachi, Hitachi-shi, Ibaraki Pref. Hitachi, Ltd. Hitachi Plant (72) Inventor Tetsuya Nagata 3-1-1 Sachimachi, Hitachi-shi, Ibaraki No. 1 Inside Hitachi, Ltd. Hitachi Plant (72) Inventor Tomojiro Hosoya 3-2-1 Sachimachi, Hitachi City, Ibaraki Prefecture Inside Hitachi Engineering Co., Ltd. (72) Inventor Masanobu Numata Hitachi City Sachi, Ibaraki Prefecture 3-1, Chomachi, Hitachi Engineering Co., Ltd.

Claims (4)

[Claims] 1. A liner anchor pitch A of a top slab of a reactor containment vessel, a liner anchor pitch B of a dry well side wall of the reactor containment vessel, and a liner anchor pitch C of a suppression chamber side wall of the reactor containment vessel. The reactor containment vessel wherein the liner anchor pitch C is set at a larger pitch than the liner anchor pitch A. 2. The containment vessel according to claim 1, wherein the liner anchor pitches A, B, and C are set to have a relative relationship of A <B <C. 3. A reactor containment vessel according to claim 1, wherein the liner anchor pitches A, B, and C are set to have a relative relationship of A = B <C. 4. The containment vessel according to claim 1, wherein the liner anchor pitches A, B, and C are set in a relative relationship of A <B = C.