JPH08262176A - Method for installing heat insulation layer of reactor pressure vessel - Google Patents

Abstract

PURPOSE: To provide a method for installing a new heat insulation vessel for preventing thermal loss due to air leakage and the damage in the heat insulation vessel when installing the pressure vessel in advance. CONSTITUTION: A nuclear pressure vessel 4 is erected on a pedestal 3 via a skirt part 13 projected around it and at the same time a heat insulation layer 14 for shutting off heat is installed around the nuclear pressure vessel 4. A heat insulation layer is divided into an upper heat insulation layer 14a provided at the upper portion of the skirt part 13 of the nuclear pressure vessel, a bottom heat insulation layer 14b provided at the bottom part of the nuclear pressure vessel 4, and a plurality of heat insulation plates 14c provided between the upper heat insulation layer 14a and the bottom heat insulation layer 14b. The upper heat insulation layer 14a and the bottom heat insulation layer 14b are installed in advance out of them, at the same time the heat insulation plate 14c is mounted to the inner surface of the skirt part 13, and then the nuclear pressure vessel 4 is installed on the pedestal 3 to connect the heat insulation plate 14c and the bottom heat insulation layer 14b.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat insulating layer installation method for shutting off heat from a reactor pressure vessel housed in a reactor containment vessel.

[0002]

2. Description of the Related Art FIG. 5 shows a conventional containment vessel (ABWR).
This is an example of an improved type rising water reactor. As shown in the figure, in this reactor containment vessel, a cylindrical pedestal 3 is erected in a bell-shaped steel plate containment vessel 2 constructed in a building 1, and a substantially cylindrical shape is provided at the upper end of this pedestal 3. The formed reactor pressure vessel 4 is supported and accommodated. Further, the inside of the steel plate storage container 2 is provided with an upper dry well 6 and a pressure suppression chamber 7 by a donut plate-shaped diaphragm floor 5 extending horizontally from the upper end of the pedestal 3.
And a lower dry well 8, and a reactor shielding wall 9 for shielding radiation and the like is provided around the reactor pressure vessel 4 located on the upper dry well 6 side. Further, the pressure suppression chamber 7 has a structure in which cooling water for condensing steam is accommodated. And
As shown in FIG. 6, the reactor pressure vessel 4 has a body portion 4
The skirt portion 13 provided on the outer peripheral portion of a is attached to the pedestal 3
The pedestal 3 can be mounted on the pedestal 3a. In FIG. 5, 10 is a vent pipe through which steam leaking to the upper dry well is made to flow to the pressure suppression chamber 7, 11 is a raise tunnel for carrying in and out of workers and carrying in and out of equipment, 12 is also an access hatch, Figure 6
Inside, 4b is an internal pump for circulating cooling water.

Further, since the reactor pressure vessel 4 reaches a high temperature when the operation is started, as shown in FIG. 8, a plurality of aluminum thin plates 15 ... The heat insulating layer 14 is provided so as to surround the heat insulating layer 14 with a predetermined space therebetween, and by suppressing the convection of the air in the heat insulating layer 14, the heat on the reactor pressure vessel 4 side is blocked and the heat loss is prevented. It is supposed to do. Further, as described above, since the reactor pressure vessel 4 is designed to be installed on the pedestal 3 by seating the skirt portion 13 on the pedestal 3a of the pedestal 3, the heat insulating layer 14 provided around the pedestal 3 as well. It is vertically divided into two parts with the skirt portion 13 as a boundary, and is composed of an upper heat insulating layer 14a provided above the skirt portion 13 and a bottom heat insulating layer 14b provided at the bottom of the skirt portion 13. Then, first, these upper heat retaining layers 14a are provided on the reactor pressure vessel 4 side,
After installing the bottom heat insulating layer 14b on the pedestal 3 side so that the upper end thereof projects, as shown in FIG.
The reactor pressure vessel 4 is lowered vertically and its skirt 1
By seating 3 on the pedestal 3, the top portion of the bottom heat insulating layer 14b bent along the inner surface of the skirt portion 13 is brought into close contact with the inner surface, and the upper heat insulating layer 14a and the bottom heat insulating layer 14b are sandwiched with the skirt portion 13 interposed therebetween. They are united to form a continuous heat retaining layer 14 to exert a good heat insulating effect.

[0004]

By the way, in such a conventional installation method, as shown in FIG.
There is a gap between the inner surface of the reactor and the bottom heat retaining layer 14b, and the high temperature air on the side of the reactor pressure vessel 4 leaks out, resulting in heat loss. Also, the inclination of the pressure vessel 4 during installation and the crane There is a problem that the skirt portion 13 comes into contact with the bottom heat insulating layer 14b and is damaged due to shake or the like.

Therefore, the present invention has been devised to solve the above problems, and its purpose is to prevent heat loss due to air leakage and damage to the heat retaining layer when the pressure vessel is installed. A new reactor pressure vessel heat insulation layer installation method that can be performed is provided.

[0006]

In order to achieve the above object, the first aspect of the invention is to install a reactor pressure vessel on a pedestal through a skirt portion projecting around the reactor pressure vessel, and In a method of installing a heat insulating layer for cutting off heat around a vessel, the heat insulating layer is provided on an upper heat insulating layer provided above a skirt portion of the reactor pressure vessel and on a bottom portion of the reactor pressure vessel. It is divided into a bottom heat insulating layer and a plurality of heat insulating plates provided between the upper heat insulating layer and the bottom heat insulating layer, of which the upper heat insulating layer and the bottom heat insulating layer are installed in advance and the heat insulating plate is attached to the skirt. After attaching to the inner surface of the section, the reactor pressure vessel is installed on a pedestal so as to connect the heat insulating plate and the bottom heat insulating layer, and the second invention is to install the heat insulating layer in the reactor. Pressure Divided into an upper heat insulating layer provided above the skirt of the vessel, a bottom heat insulating layer provided at the bottom of the reactor pressure vessel, and a plurality of heat insulating plates provided between the upper heat insulating layer and the bottom heat insulating layer. Among them, after installing the upper bottom heat insulating layer in advance, install the reactor pressure vessel on the pedestal, and then support the heat insulating plate with the upper heat insulating layer and the bottom heat insulating layer by the support provided on the inner surface of the skirt and the pedestal. The third aspect of the present invention is to install the heat insulating layer above the heat insulating layer above the skirt portion of the reactor pressure vessel, and the bottom portion below the inner surface of the skirt portion. It is divided into a heat insulating layer, and these upper heat insulating layer and bottom heat insulating layer are installed in advance, and a heat-resistant seal is placed at a position of the bottom heat insulating layer in contact with the inner surface of the skirt. The timber is provided, then, is obtained by the so install the reactor pressure vessel on the pedestal.

[0007]

As described above, according to the first aspect of the invention, since the heat insulating plate is attached to the inner surface of the skirt in advance before the reactor pressure vessel is installed on the pedestal, even if the machining accuracy of the skirt varies. A gap is not formed between the skirt portion and the heat insulating plate provided on the inner surface of the skirt portion, and air can be prevented from leaking from the gap. In addition, even if the reactor pressure vessel sways or tilts during installation, the bottom of this heat retaining plate is still open, so there is the inconvenience that the heat retaining plate will contact the pedestal and break. Can be prevented. In addition, the second invention, after installing the pressure vessel on the pedestal,
Since the heat insulating plate was fitted between the inner surface of the skirt portion and the support provided on the pedestal to connect the upper heat insulating layer and the bottom heat insulating layer, air leakage and insulation layer at the time of installation like the first invention Inconvenience such as breakage can be prevented in advance. Further, according to the third invention, by providing a heat-resistant seal member at a position in contact with the inner surface of the skirt portion of the bottom heat insulating layer, even if a gap is generated between the bottom heat insulating layer and the inner surface of the skirt portion, As with the invention, it is possible to prevent air leakage from this gap. Further, since the space between the bottom heat insulating layer and the skirt can be opened by the width of the sealing member, even if the pressure vessel is slightly shaken or tilted during installation, the bottom heat insulating layer contacts the bottom heat insulating layer.
The probability of damaging it is greatly reduced.

[0008]

An embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 shows an embodiment of the heat insulating layer installation method according to the first invention, in which 13 is a skirt portion of the reactor pressure vessel 4 and 3a is this skirt portion 1.
The pedestal 3 on which 3 is seated and installed, and 14b is the bottom heat insulating layer supported by this pedestal 3a for insulating the reactor pressure vessel 4 as described above. As shown in the figure, in this embodiment, the upper end portion of the bottom heat insulating layer 14b, that is, the pedestal 3
A portion projecting upward from a and located on the inner surface of the skirt portion 13 is divided, and the divided portion is constituted by a heat insulating plate 14c having the same structure as the bottom heat insulating layer 14b as described above. The upper end of the reactor is engaged with the engaging means 18 such as a hook provided on the inner surface of the skirt portion 13 to be in close contact therewith, and then the reactor pressure vessel 4 is seated on the pedestal 3a and installed. Therefore, as shown in the figure, when the reactor pressure vessel 4 is seated on the pedestal 3a,
The lower end of the heat insulating plate 14c is connected so as to be continuous with the bottom heat insulating layer 14b installed in advance, and the lower end of the heat insulating plate 14c is not only between the heat insulating plate 14c and the inner surface of the skirt portion 13. The upper part of the bottom heat insulating layer 14b is also connected to prevent a decrease in the heat insulating effect due to air leakage or the like. Also, this heat insulation plate 14
By providing the guide groove 19 between the lower end of c and the upper end of the bottom heat insulating layer 14b, the heat insulating plate 14c and the bottom heat insulating layer 14b can be easily connected at the same time by simply lowering the pressure vessel 4. It is possible to prevent the heat insulating plate 14c from dropping. As the engaging means 18 for engaging the heat retaining plate 14c with the inner surface of the skirt portion 13, as shown in FIG. 2 (A), a stopper 20 and a rivet 21 are used, or the structure shown in FIG. A bolt 22 may be used as shown in FIG. Further, as shown in the figure, the heat insulating plate 14c is finely divided in the height direction,
By connecting these with a rivet 21 or the like, the shape may be appropriately controlled.

Next, FIG. 3 shows an embodiment of a heat insulation layer installation method according to the second invention. This embodiment is the same as the heat insulation plate 14c used in the first invention except that the reactor pressure vessel is used. After the skirt portion 13 of No. 4 is seated on the pedestal 3a, it is installed. And for that purpose, FIG.
As shown in (A), before the skirt portion 13 is seated on the pedestal 3a, an annular lower support 23 for supporting the lower end of the heat insulating plate 14c is provided on the pedestal 3a side, and the inner surface side of the skirt portion 13 is provided. Is provided with a hook-shaped upper support 24 that supports the lower end of the heat insulating plate 14c.
3 and the heat insulating plate 14c is fitted between the upper supports 24, and the heat insulating plate 14c is sequentially arranged along the circumferential direction of the skirt portion 13 as shown in FIG.
And the bottom heat insulating layer 14b are integrally connected. Therefore,
Not only between the skirt portion 13 and the heat insulating plate 14, but also the heat insulating plate 14c
And the bottom heat insulating layer 14b are easily connected, and effective heat insulation can be achieved. Further, since the heat insulating plate 14 is installed after the skirt portion 13 is seated, it is possible to prevent the heat insulating layer from being damaged when the pressure vessel 4 is installed.

Next, FIG. 4 shows an embodiment of the third invention. As shown in the figure, this embodiment has a base 3
A seal member 25 is provided on the top outer edge side of the conventional bottom heat retaining layer 14b protruding above a, that is, on the contact surface with the skirt portion 13, whereby the skirt portion 1 is formed.
It is possible to prevent the high temperature air from leaking out from the side of the reactor pressure vessel 4 even if there is a gap between the No. 3 and the bottom heat insulating layer 14b.

This seal member 25 is used for the reactor pressure vessel 4
Since it reaches a high temperature in the surroundings, a material having heat resistance higher than that is used, and for example, a material made of metal fiber such as stainless cloth is suitable. Further, since the gap between the skirt portion 13 and the bottom heat insulating layer 14b is non-uniform, in order to give the seal member 25 an appropriate thickness, the band-shaped stainless cloth 25a is folded in its length direction, After inserting a heat resistant web, for example, a stainless web 25b, in between, the stainless cloth 25
The mating surface of a is fixed to the heat retaining layer 14 side by a cross stopper metal fitting 25c such as a rivet, and further, a cross pressing metal fitting 25d is provided under the metal fitting so as to give the web 25b elasticity and prevent it from expanding and crushing. This is to prevent it.

As a result, as described above, it is possible to prevent air leakage between the skirt portion 13 and the heat retaining layer 14 due to variations in processing accuracy, and of course, on the premise that a gap is formed between the skirt portion 13 and the heat retaining layer 14. Bottom heat insulation layer 1
Since the diameter of 4b can be made slightly smaller, the probability that the skirt portion will come into contact with the bottom heat insulating layer 14b when the skirt portion 13 is seated on the pedestal 3a is low, and the heat insulating layer 1
Inconvenience such as breakage of No. 4 can be prevented in advance.
Although the present invention can exert sufficient effects even with the configuration of the above embodiment, it can be combined with the heat insulating plate 14c of the first invention and the second invention, and in this case, Greater heat insulation effect is obtained.

[0014]

In summary, according to the present invention, since there is no gap between the skirt portion and the heat retaining layer even if there are variations due to the processing accuracy of the skirt portion, the high temperature air on the pressure vessel side is insulated. It is possible to prevent leakage to the outside of the layer and prevent deterioration of the heat insulation effect.Moreover, even if the reactor pressure vessel sways or tilts during installation, the insufficiency such as damage or crushing of the heat retaining layer will occur. It has excellent effects such as prevention.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing an embodiment of the first invention.

FIG. 2A is a side view showing a first modified embodiment of the first invention. (B) is a side view showing a second modification of the first invention.

FIG. 3A is a side view showing an embodiment of the second invention. (B) is a front view of (A).

FIG. 4 is an enlarged side view showing an embodiment of the third invention.

FIG. 5 is an overall view showing a configuration of a conventional reactor containment vessel.

FIG. 6 is a side view showing an installation structure of a conventional reactor containment vessel and an installation position of a heat retaining layer.

FIG. 7 is an explanatory view showing a state in which a conventional reactor pressure vessel is seated on a pedestal of a pedestal.

FIG. 8 is an exploded perspective view showing a structure of a conventional heat retaining layer.

FIG. 9 is an explanatory diagram showing a state in which a gap is formed between the skirt portion of the pressure container and the heat retaining layer.

[Explanation of symbols]

 3 Pedestal 4 Reactor Pressure Vessel 13 Skirt 14 Thermal insulation layer 14a Upper thermal insulation layer 14b Bottom thermal insulation layer 14c Thermal insulation plate 23, 24 Support 25 Seal member

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Kumiko Araki 1 Shin-Nakahara-cho, Isogo-ku, Yokohama-shi, Kanagawa Ishi Kawashima Harima Heavy Industries, Ltd. Yokohama Engineering Center (72) Inventor, Otomo Okamoto Isogo, Yokohama-shi, Kanagawa Shin-Nakahara-cho, Tokyo-shi Ishikawajima Harima Heavy Industries Ltd. Yokohama Engineering Center

Claims (3)

[Claims] 1. A reactor pressure vessel is erected on a pedestal through a skirt portion that extends around the reactor pressure vessel, and
In a method of installing a heat insulating layer for shutting off heat around the reactor pressure vessel, the heat insulating layer is an upper heat insulating layer provided above the skirt portion of the reactor pressure vessel,
A bottom heat insulating layer provided at the bottom of the reactor pressure vessel,
It is divided into a plurality of heat retaining plates provided between the upper heat retaining layer and the bottom heat retaining layer, of which the upper heat retaining layer and the bottom heat retaining layer are preliminarily installed, and the heat retaining plate is attached to the inner surface of the skirt portion. After that, this reactor pressure vessel is installed on a pedestal, and the above-mentioned heat insulation plate and the bottom heat insulation layer are connected to each other. 2. A reactor pressure vessel is erected on a pedestal through a skirt portion that projects around the reactor pressure vessel, and
In a method of installing a heat insulating layer for shutting off heat around the reactor pressure vessel, the heat insulating layer is an upper heat insulating layer provided above the skirt portion of the reactor pressure vessel,
A bottom heat insulating layer provided at the bottom of the reactor pressure vessel,
Divide into a plurality of heat insulating plates provided between the upper heat insulating layer and the bottom heat insulating layer, of which the bottom heat insulating layer is installed in advance and then the reactor pressure vessel is installed on the pedestal, and then the skirt A heat insulation layer installation method for a reactor pressure vessel, characterized in that the heat insulation plate is installed between the top heat insulation layer and the bottom heat insulation layer by means of supports provided on the inner surface of the section and the pedestal. 3. A reactor pressure vessel is erected on a pedestal through a skirt portion that extends around the reactor pressure vessel, and
In a method of installing a heat insulating layer for shutting off heat around the reactor pressure vessel, the heat insulating layer is an upper heat insulating layer provided above the skirt portion of the reactor pressure vessel,
The skirt is divided into an inner surface and a bottom heat insulating layer provided at the bottom, and the upper heat insulating layer and the bottom heat insulating layer are preliminarily installed, and a heat-resistant seal member is provided at a position of the bottom heat insulating layer in contact with the inner surface of the skirt. And then installing the reactor pressure vessel on the pedestal, the method for installing a heat insulation layer of the reactor pressure vessel.