JPH0455795A - Nuclear reactor containment vessel - Google Patents

Abstract

PURPOSE:To simplify structures in suppression chamber by supporting the weight of vent pipes and vent header with welding on side wall. CONSTITUTION:A multitude of vent pipes 4 are penetrated in and welded on the side wall 21 of suppression chamber 3, and a jet deflector 28 is attached at the end of the vent pipes 4. A vent header 26 of annular shape is arranged horizontally in the chamber 3 to connect with vent pipes 4. Downcomers 27 are hung down from the ceiling of the chamber 3 with hangers 29 so that their top ends pass through the header 26 and bottom ends, through pool water W. By welding and supporting such heavy weight as vent pipes 4, header 26, downcomers 27, hangers 29, vacuum breaker valves 30 and manholes 31 on the side wall 21, vertical wall 24 and ceiling wall 25, the structure of the chamber 3 can be simplified and construction work becomes easy.

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to a nuclear reactor containment vessel, and particularly to a technique for arranging a dry well and a suppression chamber adjacent to each other inside and outside a side wall.

[Prior Art j] As a conventional technology for a reactor containment vessel in a boiling water reactor, there is, for example, the technology shown in FIG. 3 of Utility Model Application No. 61-09ii90.

In the reactor containment vessel of this example in FIG.
a pressure suppression chamber (suppression chamber) 3 that stores
A vent pipe 4, a pressure suppression chamber nozzle 5, a bellows joint 6, a vent header 7, a downcomer 8, etc. are provided, and in the event that an accident such as a pipe breakage occurs and steam is spewed out, the interior of the dry well 2 will be protected. Due to the abnormal pressure rise, steam is released into the pool water W via the vent pipe 4, vent header 7, and downcomer 8, and is cooled and condensed to keep the internal pressure of the dry well 2 below a certain level and restart the reactor. This is to maintain the soundness of the system.

The weight of the reactor pressure vessel 1 is determined by the foundation anchor 10 buried in the foundation 9 made of concrete, the bottom support ii erected from the foundation anchor 10, and the steel support ii on the bottom support ii. It has a structure in which it is supported by a reactor pedestal 13 erected from the bottom of the vessel 12.

[Problems to be Solved by the Invention] However, the structure shown in the example in FIG. 3 causes various problems as described below.

■The construction work of the reactor containment vessel and the construction work of the biological shielding wall (reactor building) 14, which is formed by pouring concrete around the reactor containment vessel, are interrelated, resulting in a long overall construction period. - The amount of equipment and parts related to the suppression chamber 3 increases, for example, between the suppression chamber 3 and the bottom of the steel container 12.
Since a part of the biological shielding wall 14 is interposed, construction work is likely to interfere with each other, increasing the construction effort; ■ The support structure of the reactor pressure vessel 1 becomes complicated, which is disadvantageous in terms of ensuring strength. (1) There are many restrictions when increasing the volumes of the suppression chamber 3 and pool water W.

The present invention has been made in view of the above circumstances, and is to (1) simplify the structure between the try well and the Sable Funyon chamber, and (2) shorten the construction period of the reactor containment vessel. That (3
) To reduce the restrictions when increasing the volume of a dry well or sabre I John chamber.

The purpose is to

1. Inappropriate Means to Solve the Problem" The present invention proposes three means to solve the problem.

The first means includes a steel vessel that defines a dry well around the reactor pressure vessel, and sub-cells that define a dry well around the side wall of the steel vessel I, with the side wall being part of an inner partition wall. The reactor containment vessel is equipped with a single chamber.

The second means includes a vent pipe penetratingly supported by the side wall, a vent header connected to the vent pipe and integrally supported by the side wall, and a vent header connected to the vent header and connected to the pool water of the suppression chamber. The reactor containment vessel is obtained by adding a structure including a communicating downcomer to the first means.

The third means is a structure in which the inner bottom surface of the dry well and the inner bottom surface of the suppression chamber are arranged on the same plane.
The reactor containment vessel is added to the first means or the second means.

In the first method, a dry well and a suppression chamber are arranged inside and outside the side wall, so pressure based on the head difference of the pool water is applied to a part of the side wall. By keeping it high, deformation is suppressed. The side walls of steel containers are constructed separately from the concrete pouring operations.

In the second method, the weight of the vent pipe, vent header, etc. is supported by the side wall, assembly is performed by welding, etc., and there is no interference with concrete pouring work.

In the third method, the upper surface of the foundation is flat, and the side walls and reactor pedestal are constructed on top of the foundation. The reactor pedestal is erected directly on the foundation, resulting in a simple structure, which is advantageous in terms of ensuring strength.

"Embodiment" Hereinafter, an embodiment of a reactor containment vessel according to the present invention will be described with reference to FIGS. 1 and 2. In the figure, parts common to the conventional example are given the same reference numerals to simplify the explanation.

In the reactor containment vessel in this embodiment, the steel vessel 20 that defines the dry well 2 around the reactor pressure vessel l has a foundation (concrete structure) 9 formed by pouring concrete. Basic anchor 10
The side wall 21 of the lower part of the steel container 20 is connected by welding or the like to the bottom liner 22 affixed to the upper surface of the base part 9, making the dry well 2 a sealed structure. Around 21, a suppression chamber 3 using the side wall 21 as a part of a partition wall is arranged.

The subledge tongue chamber 3 is housed in a disk-shaped storage space 23 in a part of the reactor building 14, and includes a side wall 21 used as a partition wall, a bottom liner 22 outside the side wall 21, and a foundation anchor lO. A sealed annular space is formed by a vertical wall 24 rising from the bottom liner 22 and a ceiling wall 25 connecting the vertical wall 24 and the side wall 21.

As shown in FIG. 2, the subledge tongue chamber 3 includes a plurality of vent pipes 4 extending horizontally through the side wall 21, and a vent header 26 connected to the vent pipes 4.
and a plurality of downcomers 27 connected to the vent header 26 are attached.

More specifically, the vent pipes 4 are attached to the side wall 21 by welding or the like, and as shown in FIG. A jet deflector 28 is also attached.

As shown in FIG. 1, the vent header 26 has a fan-shaped cross section, for example, communicates with the inner opening of the vent pipe 4, and is disposed horizontally and annularly inside the suppression chamber 3.

The downcomer 27 is supported by being suspended from the ceiling wall of the suppression chamber 3 by a hanging holder 29, and its upper end is communicated with the inside of the vent header 26, and its lower end is connected to the pool water W. It is communicated.

Further, the bottom liner 22 of the dry well 2 and the bottom liner 22 of the suppression chamber 3 are arranged on the same plane by matching the level of the upper surface of the base part 9.

The reactor pedestal I3, like the side wall 2j and the vertical wall 24 of the suppression chamber 3, is erected directly from the foundation anchor 10 and the bottom liner 22.

In addition, in the figure, the reference numeral 30 is a vacuum breaker valve, 3] is a manhole, and 32 is a platform.
are provided in the circumferential direction along the upper interior of the suppression chamber 3, as shown in FIG. 1, and partially connect the inner and outer walls of the suppression chamber 3 in the radial direction as shown in FIG. , extending to the bottom of the vacuum breaker valve 30.

If the reactor containment vessel is configured as described above,
Even if there is no pressure difference between the dry well 2 and the upper space of the subledge tongue chamber 3, pressure based on the head difference of the pool water W will be applied to the side wall 21 of the steel container 20. However, this water head difference is supported by considering the strength of the side wall 21.

As is clear from the comparison with the example in FIG. 3, there is no concrete-casting part in the vicinity of the side wall 21, and the vertical wall 24 and ceiling wall 25 of the suppression chamber 3 are covered with atoms that are the surrounding concrete structure. Furnace building 14
Coupled with the fact that it is separated from the reactor building 14, the structure is simplified, and the construction work of the subledge tongue chamber 3 is carried out separately from the concrete pouring work of the reactor building 14.

Assembling and installing the vent pipe 4, vent header 26, downcomer 27, hanging fixture 29, vacuum breaker valve 30, manhole 31, etc. requires one task, but the side wall 2], vertical wall 24
Since the weight is supported by the ceiling wall 25 and it is attached by welding or the like, it can be carried out as an independent work without interfering with the concrete pouring work.

Considering the volume of suppression chamber 3,
As is clear from a comparison between FIG. 1 and FIG. 3, the suppression chamber 3 in FIG. and that there is no space left behind.
Since it has a rectangular cross section and is similar in shape to the storage space 23, it is easy to use the space effectively, which is advantageous in terms of increasing capacity.

In addition, the reactor pedestal 13 is constructed by standing a steel double cylinder on the foundation anchor IO of the foundation 9 and the bottom liner 22, and filling the inside with concrete. Since the bottom liner 22 of the suppression chamber 3 is flat, it can be carried out independently or in parallel with the construction work of the steel vessel 20 and the suppression chamber 3.

On the other hand, if an accident such as a pipe rupture occurs in the dry well 2 and steam is ejected I7 and the internal pressure of the dry well 2 becomes high, the jet deflector 28 will reduce the impact caused by the jet flow and the pressure will be reduced. The fluid is distributed in the circumferential direction by being sent from the vent pipe 4 to the vent header 26, and furthermore, the pressure fluid is ejected from the downcomer 27 into the pool water W, thereby cooling and condensing the steam. 2. Suppress the pressure increase. Note that by releasing the pressure fluid, the suppression chamber 3
If the pressure in the upper space becomes high, the vacuum breaker valve 3
0 operates to prevent a pressure difference between the dry well 2 and the suppression chamber 3 from occurring.

"Effects of the Invention" As explained above, the reactor containment vessel of the present invention provides the following excellent effects.

In the first invention, the structure of the partition wall of the suppression chamber can be simplified because the dry well and the sub-lend chamber are arranged next to each other inside and outside the side wall of the steel container. can. ■Construction work for the steel vessel and sub-reinforcement chamber does not involve direct concrete pouring work, and the construction period for the entire reactor containment vessel can be shortened. - Since there is no concrete I# structure between the dry well and the suppression chamber, the volumes of the dry well and the suppression chamber can be made smaller.

In the second invention, the weight of the vent pipe, vent header, etc. is supported by the side wall of the steel container and is attached by welding or the like.
In addition to the effects mentioned above, the structure of the suppression chamber can be simplified and the construction work of the sub-reaction chamber can be facilitated.

In the third invention, since the inner bottom surface of the dry well and the inner bottom surface of the suppression chamber are arranged on the same plane, in addition to the effects of the first invention and the second invention, The side walls and reactor pedestal are built on top of the foundation, and the reactor pedestal is erected directly on the foundation, resulting in a simple structure, which is particularly advantageous in terms of ensuring strength. .

[Brief explanation of the drawing]

Fig. 1 is a front sectional view showing one embodiment of the reactor containment vessel according to the present invention, Fig. 2 is a view taken along the line ■-■ in Fig. 1, and Fig. 3 is a conventional example of the reactor containment vessel. FIG. M, W...Pool water.

Claims (1)

[Scope of Claims] i. A steel vessel that defines a dry well around a reactor pressure vessel, and a suppression chamber that defines a side wall of the steel vessel as part of an inner partition wall. A nuclear reactor containment vessel characterized by comprising: ii. A vent pipe penetratingly supported by the side wall of the steel container, a vent header connected to the vent pipe and integrally supported by the side wall, and connected to the vent header and communicating with the pool water of the suppression chamber. The reactor containment vessel according to claim 1, further comprising a downcomer. iii. The nuclear reactor containment vessel according to claim 1 or 2, wherein the inner bottom surface of the dry well and the inner bottom surface of the suppression chamber are arranged on the same plane.