JPH05232281A - Reactor container - Google Patents

Abstract

PURPOSE:To attain maintenance of submergence of a core for a long period effectively at the time of a coolant loss accident and to prevent submersion of a control rod driving device and others under water when the coolant loss accident occurs in the upper part of a reactor pressure vessel or when any misoperation should occur. CONSTITUTION:A partition wall 8 separating a dry well part 4 into upper and lower parts is provided, in a reactor container, between a reactor pressure vessel 2 and a suppression chamber 5. A communication pipe 9 which is disposed in this partition wall 8 and makes the upper and lower parts of the dry well part communicate with each other and of which one end opened in the upper part of the dry well 4 is located at a higher position than a hole provided in a vent pipe 6, is provided.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a containment vessel for a nuclear reactor.

[0002]

2. Description of the Related Art A conventional technique will be described below with reference to the drawings.

FIG. 4 is a schematic diagram showing a conventional reactor containment vessel. The reactor core 1 is housed in a reactor pressure vessel 2. A pressure reducing valve 3 is arranged above the reactor pressure vessel 2. A periphery of the reactor pressure vessel 2 is surrounded by a dry well portion 4, and a suppression chamber 5 storing pool water (hereinafter referred to as suppression pool water) is provided around the dry well portion 4. One end of the suppression chamber 5 opens into the dry well portion 4,
A vent pipe 6 having the other end opened to the suppression pool water is arranged. In addition, one or a plurality of holes may be provided in the vent pipe 6 on the reactor pressure vessel 2 side. Further, a gravity drop type water injection equipment 7 is arranged above the suppression chamber 5.

When a coolant loss accident such as pipe breakage occurs, an emergency core cooling device (not shown) operates,
The pressure reducing valve 3 opens in response to an accident signal, etc., and the reactor pressure vessel 2
The pressure inside is rapidly reduced and a coolant is injected into the reactor pressure vessel 2 from the gravity drop type water injection equipment 7 to cool the reactor core 1. However, since this injection period is short, it is necessary to secure a sufficient amount of water for submerging the reactor pressure vessel 2 from the core 1 in order to keep the core 1 flooded even after the water injection is completed. ..

If the emergency core cooling device malfunctions, the coolant is injected from the gravity drop type water injection equipment 7 into the reactor pressure vessel 2 to raise the water level of the coolant and eventually the pressure reducing valve. There was a risk that the coolant would overflow from No. 3 and the important equipment such as the control rod drive device arranged below the dry well 4 would be submerged.

[0006]

As described above, in the prior art, a large amount of coolant was required to maintain the core flooded in the event of a coolant loss accident. In addition, if there is a loss of coolant accident in the upper part of the reactor pressure vessel or if the emergency core cooling device malfunctions, the control rod drive installed under the dry well in the reactor containment vessel There was a risk that important equipment such as equipment would be submerged in water and its integrity would be impaired.

Therefore, the present invention has been made in view of the above problems, and effectively maintains the core flooding for a long period in the event of a coolant loss accident, and there is a coolant loss accident in the upper part of the reactor pressure vessel. It is an object of the present invention to provide a reactor containment vessel that prevents submersion of important equipment such as a control rod drive device in the unlikely event that the emergency core cooling device malfunctions.

[0008]

In order to achieve the above object, the present invention provides a dry well portion for accommodating a reactor pressure vessel, and a suppression chamber arranged around the dry well portion for storing pool water. In a reactor containment vessel having a vent pipe having one end opened in pool water of the suppression chamber and the other end opened in the dry well, a partition wall dividing the dry well portion into an upper portion and a lower portion, It is characterized in that it is provided with a communication pipe penetrating this partition wall and having one end at a position higher than a hole formed on the dry well side of the vent pipe.

Further, a dry well portion for accommodating a reactor pressure vessel having a pressure reducing valve on the upper portion, a suppression chamber arranged around the dry well portion for storing pool water, and a pool water of the suppression chamber are provided. In a nuclear reactor containment vessel having a vent pipe having one end opened and the other end opened in the dry well, a pool portion including a discharge port of the pressure reducing valve and connected to the vent pipe may be arranged. Characterize.

Further, a dry well portion for accommodating a reactor pressure vessel having a pressure reducing valve at the upper portion, a suppression chamber arranged around the dry well portion for storing pool water, and a pool water of the suppression chamber are provided. In a reactor containment vessel having a vent pipe having one end opened and the other end opened in the dry well, one end is connected to the discharge port of the pressure reducing valve, and the other end is opened in the suppression chamber. It is characterized in that it has a pipe.

[0011]

In the invention according to claim 1, when the pipe breaks in the upper portion of the reactor pressure vessel, only the inside of the reactor pressure vessel and the upper portion of the dry well are submerged. When pipe breakage occurs in the lower part of the reactor pressure vessel, the inside of the reactor pressure vessel, the lower part of the dry well and the inside of the communication pipe are submerged. In the unlikely event of a malfunction of the emergency core cooling device, if the coolant overflows from the pressure reducing valve, the coolant will accumulate in the upper part of the dry well, and the water level of the coolant will not rise to the dry well opening surface of the communication pipe, It flows into the suppression chamber through the vent pipe hole.

According to the second aspect of the present invention, when the coolant overflows from the pressure reducing valve due to an erroneous operation, the coolant does not flow out to the lower part of the dry well but is stored in the pool section, and is a vent pipe used as the pool section. Flow out into the suppression chamber via.

According to the third aspect of the present invention, when the coolant overflows from the pressure reducing valve due to a malfunction, the coolant flows into the suppression chamber through the pipe connecting the pressure reducing valve and the suppression chamber.

[0014]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic view of the reactor containment vessel according to the first embodiment of the present invention. In the figure, the same parts as those in FIG. 4 are designated by the same reference numerals, and the description of the overlapping parts will be omitted. A partition wall 8 is provided between the reactor pressure vessel 2 and the suppression chamber 5 to separate the dry well portion 4 into an upper portion 4a and a lower portion 4b. A communication pipe 9 is arranged in the partition wall 8. The communication pipe 9 is composed of the upper part 4a and the lower part 4 of the dry well 4.
b, one end of which is located higher than the hole 14 provided at the reactor pressure vessel 2 side of the vent pipe 6 at one end
It has an opening.

When a coolant loss accident such as pipe breakage occurs, the pressure reducing valve 3 is opened in response to an accident signal or the like, and the pressure inside the reactor pressure vessel 2 is quickly reduced to cool from the gravity drop type water injection equipment 7. Material is injected into the reactor pressure vessel 2 for a short period of time,
Cool the core 1.

When a coolant loss accident such as pipe breakage occurs in the upper portion of the reactor pressure vessel 2, only the inside of the reactor pressure vessel 2 and the dry well upper portion 4a can be submerged by the partition wall 8. The submergence of water inside the reactor pressure vessel 2 allows the core 1 to be flooded. Since only the dry well upper portion 4a is submerged, it is possible to prevent submersion of important equipment such as the control rod drive device arranged in the dry well lower portion 4b.

On the other hand, when a coolant loss accident such as pipe breakage occurs in the lower portion of the reactor pressure vessel 2, the dry well lower portion 4b, the dry well upper portion 4a and the lower portion 4b are formed by the inside of the reactor pressure vessel 2 and the partition wall 8. It is possible to submerge the inside of the communication pipe 9 which communicates with each other. As a result, the reactor core 1 can be flooded. As described above, when a coolant loss accident occurs, efficient cooling of the core can be achieved, and maintenance of flooding of the core for a long time can be achieved.

If the emergency core cooling device malfunctions and the pressure reducing valve 3 opens, the gravity drop type water injection system 7
A coolant is injected into the reactor pressure vessel 2 from the reactor, and this coolant submerges the reactor core 1 and then overflows from the pressure reducing valve 3 to form the partition wall 8
Collect on the upper part 4a of the dry well. At this time, the water level of the coolant does not rise to the opening of the dry well 4 of the communication pipe 9, but flows into the suppression chamber 5 through the hole 14 provided in the vent pipe. Since the coolant does not flow out to the lower part of the dry well 4, it is possible to prevent submersion of important equipment such as the control rod drive device arranged below the dry well 4.
Next, FIG. 2 shows a schematic diagram of a reactor containment vessel according to a second embodiment of the present invention. In the figure, the same parts as those in FIG. 4 are designated by the same reference numerals, and the description of the overlapping parts will be omitted.

In FIG. 2, the suppression chamber 5
Above the above, there is provided a pool section 10 including the discharge port of the pressure reducing valve 3 and having one end of the vent pipe 6 opened. The pool portion 10 is the upper surface of the suppression chamber 5, and a weir 11 is provided in the dry well 4 of the vent pipe 6 near the opening, and the weir 11 and the pressure reducing valve 3 in the reactor pressure vessel 2 are joined. The outer side is the side of the pool. Also,
A plate 12 provided horizontally below the pressure reducing valve 3 and between the reactor pressure vessel 2 and the vent pipe 6 serves as the bottom surface of the pool portion.

Should the emergency core cooling device malfunction, the pressure reducing valve 3 is opened, the pressure in the reactor pressure vessel 2 is quickly reduced, and the coolant is injected from the gravity drop type water injection equipment 7. Then, the reactor core 1 is submerged in water, and eventually the pressure reducing valve 3 overflows. The overflowed coolant does not flow out to the lower part of the dry well 4, and in the pool part 10, the dry well 4 of the vent pipe 6
When the coolant is stored up to the height of the internal opening, and the coolant overflows from the pressure reducing valve 3, the coolant flows into the suppression chamber 5 through the vent pipe 6. For this reason, the coolant does not flow out to the lower part of the dry well 4, and it is possible to prevent submersion of important machinery such as the control rod drive device arranged below the dry well 4.

Next, FIG. 3 shows a schematic diagram of a reactor containment vessel according to a third embodiment of the present invention. In the figure, those parts that are the same as those corresponding parts in FIG. 4 are designated by the same reference numerals, and a description of the overlapping parts will be omitted.
The pressure reducing valve 3 and the suppression chamber 5 arranged above the reactor pressure vessel 2 are connected by a pipe 13.

Should a malfunction occur, the pressure reducing valve is opened, the pressure in the reactor pressure vessel 2 is quickly reduced, and a coolant is injected from the gravity drop type water injection equipment 7. The water level of the coolant rises, and eventually the pressure reducing valve 3 overflows. The overflowed coolant does not flow to the lower part of the dry well 4, but directly flows into the suppression chamber through the pipe 13. With the above structure, the same operation and effect as those of the second embodiment can be obtained in the third embodiment.

[0024]

As described above, according to the present invention, when there is a coolant loss accident such as pipe breakage, the submergence of water inside the reactor pressure vessel effectively maintains the flooding of the core for a long period of time. Can be achieved.

If there is a coolant loss accident such as pipe breakage in the upper part of the reactor pressure vessel, or if the emergency core cooling device malfunctions, the coolant will flow out to the lower part of the dry well. Therefore, it is possible to prevent submergence of important equipment such as the control rod drive device. Therefore, the integrity of the device can be maintained, and the safety of the nuclear reactor can be significantly improved.

[Brief description of drawings]

FIG. 1 is a schematic diagram of a reactor containment vessel according to a first embodiment of the present invention.

FIG. 2 is a schematic diagram of a reactor containment vessel according to a second embodiment of the present invention.

FIG. 3 is a schematic diagram of a reactor containment vessel according to a third embodiment of the present invention.

FIG. 4 is a schematic diagram of a conventional reactor containment vessel.

[Explanation of symbols]

 1 ... Reactor core 2 ... Reactor pressure vessel 3 ... Pressure reducing valve 4 ... Dry well part 5 ... Suppression chamber 6 ... Vent pipe 7 ... Gravity drop type water injection equipment 8 ... Partition wall 9 ... Communication pipe 10 ... Pool part 11 ... Weir 12 ... Plate 13 ... Piping 14 ... Hole

Claims (3)

[Claims] 1. A dry well portion for accommodating a reactor pressure vessel, a suppression chamber arranged around the dry well portion for storing pool water, and one end opened in the pool water of the suppression chamber and the other end. In a reactor containment vessel having a vent pipe opening in the dry well, a partition wall dividing the dry well portion into an upper part and a lower part, and one end penetrating the partition wall on the dry well side of the vent pipe. And a communication pipe at a position higher than the hole formed in the reactor containment vessel. 2. A dry well portion for accommodating a reactor pressure vessel having a pressure reducing valve on the upper portion, a suppression chamber arranged around the dry well portion for storing pool water, and a pool water of the suppression chamber. In a nuclear reactor containment vessel having a vent pipe having one end opened and the other end opened in the dry well, a pool portion including a discharge port of the pressure reducing valve and connected to the vent pipe may be arranged. Characteristic containment vessel. 3. A dry well portion for accommodating a reactor pressure vessel having a pressure reducing valve on the upper portion, a suppression chamber arranged around the dry well portion for storing pool water, and a pool water in the suppression chamber. In a reactor containment vessel having a vent pipe having one end opened and the other end opened in the dry well, one end is connected to the discharge port of the pressure reducing valve, and the other end is opened in the suppression chamber. A reactor containment vessel characterized by arranging pipes that are installed.