JPH0636062B2 - Cooling device in the reactor containment vessel - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Object of the Invention (Field of Industrial Application) The present invention relates to a cooling device for a reactor containment vessel in a nuclear power plant.

(Prior Art) Conventionally, in a nuclear reactor containment vessel in a nuclear power plant such as a nuclear power plant, a reactor pressure vessel 1 is placed in the center on a pedestal 2 as shown in a sectional view of a main part of FIG. The cylindrical shielding wall 3 is installed around the same for the purpose of blocking radiation and heat from the reactor pressure vessel 1. Various devices for operating the reactor are installed by using the inside of the reactor containment vessel 4 which covers the entire reactor pressure vessel 1 and the shielding wall 3 as a dry well. In particular, the space 5 between the reactor pressure vessel 1 and the shield wall 3 becomes a high temperature area due to heat radiation from the reactor pressure vessel 1. Therefore, an annular air supply nozzle 6 is arranged below the shielding wall 3, and cold air is supplied from a local cooler 8 via an air supply duct 7 penetrating the shielding wall 3 to provide a reactor in the space 5. The pressure vessel 1 is blown out substantially uniformly along the outer periphery of the pressure vessel 1 for cooling. This cold air cools the space 5 along the outer periphery of the reactor pressure vessel 1, rises, flows out from the uppermost portion of the shielding wall 3, diffuses, passes through the reactor containment vessel 4, and passes through the reactor containment vessel 4 Together with the atmosphere inside, it is sucked into the suction port 8a of the local cooler 8 and cooled again.

Further, a dehumidifier 11 for preventing dew condensation in the reactor containment vessel is installed in a dry well in the reactor containment vessel 4 for dehumidification cooling.

(Problems to be Solved by the Invention) Since the space portion 5 between the reactor pressure vessel 1 and the shielding wall 3 is vertically long, the cold air supplied from the lowermost portion of the shielding wall 3 reaches the uppermost portion of the shielding wall 3. By the time the temperature rises significantly, the cooling effect decreases near the top. Further, various nozzles 9 connected to the reactor pressure vessel 1 penetrate through the shielding wall 3, and an opening 10 is provided in this portion for periodical inspection. For this reason, the cold air is blown by these openings 10 and nozzles 9.
There is also a problem that the cold air does not reach the uppermost part of the shielding wall 3 sufficiently because it may flow out of the shielding wall 3 through the gap. Further, in the vicinity of the upper part of the shielding wall 3, hot air stays and the temperature difference with the lower part of the reactor containment vessel 4 in which the local cooler 8 is installed becomes large, making it difficult to equalize the temperature of the dry well. There was a problem that became.

The present invention has been made to solve the above problems, and efficiently removes heat in the high temperature area around the space 5 between the reactor pressure vessel 1 and the shield wall 3 and the bellow seal portion of the containment vessel. It is an object of the present invention to provide a cooling device in a reactor containment vessel, which can be implemented so that a high temperature part does not occur near the upper part of the shielding wall, and the temperature distribution of the upper part and the lower part in the reactor containment vessel can be appropriately adjusted.

[Structure of the Invention] (Means for Solving the Problems) In the present invention, a dehumidifier for preventing dew condensation is connected to a local cooler installed in a drywell in a reactor containment vessel, and cold air cooled by the dehumidifier is used as described above. It is characterized by connecting an air supply duct blowing out to a high temperature area of the dry well.

(Operation) Air cooled by the local cooler is further cooled by the dehumidifier in the space of the reactor pressure vessel, which is the heat source, and the shielding wall, which is the heat shield, and the cold air is blown from the air supply duct to cool it. I do. Therefore, the air volume in the space can be reduced, the temperature rise can be reduced, and the cooling effect can be obtained. Especially, the thermal stress of the shielding wall is reduced.

Similarly, cold air from the dehumidifier can be blown out near the upper part of the shielding wall to reduce the retention of high-temperature air and equalize the temperature in the dry well.

(Embodiment) An embodiment of the present invention will be described with reference to FIG. In addition,
The same components as those of the above-mentioned conventional technique are designated by the same reference numerals, and detailed description thereof will be omitted.

FIG. 1 is a cross-sectional view of a main part of the reactor containment vessel, in which a reactor pressure vessel 1 installed in a pedestal 2 at the center and a cylindrical shield wall 3 are provided around the reactor pressure vessel 1.

At the bottom of the space 5 between the reactor pressure vessel 1 and the shielding wall 3, an annular air supply nozzle 12a for blowing cold air is installed, and an air supply duct 7 is connected to supply cold air from a local cooler 8.

A dehumidifier 11 is installed in the middle of the air supply duct 7, and the air cooled by the local cooler 8 is further cooled by the dehumidifier 11 and supplied.

Similarly, the air cooled by the local cooler 8 and the dehumidifier 11 is also supplied to the upper area of the shield wall 3 where the air passing through the space 5 between the reactor pressure vessel 1 and the shield wall is blown into the drywell space. 7b are arranged in an annular shape, and the air supply nozzle 12b
It will be blown out from.

Next, the operation of the above configuration will be described.

The air in the drywell space is circulated and cooled by the local cooler 8, but the air cooled by the local cooler 8 is removed by the dehumidifier 11
Is further cooled and supplied as cold air from the air supply nozzle 12a through the air supply duct 7 to the space 5 between the reactor pressure vessel 1 and the shield wall 3. Since the temperature is lowered by the dehumidifier 11 and the supply amount to the space 5 can be reduced, the pressure inside the shielding wall 3 becomes small, and the leakage to the heat insulating material of the reactor pressure vessel 1 and the outflow of cold air from the opening 10 occur. The cooling efficiency is increased. The temperature rise is also small and the cooling effect is large.

The air that has flowed through the space 5 and has a high temperature is blown out from the upper portion of the shielding wall 3 into the upper space of the dry well, and becomes a high temperature area. In this high temperature area, the cold air that has flowed through the local cooler 8 and the dehumidifier 11 installed above the dry well and is cooled is blown out from the air supply nozzle 12b and diffused and cooled. In this way, it becomes possible to prevent high temperature air from staying in the high temperature area of the dry well.

[Advantages of the Invention] According to the present invention, the cooling effect of the reactor pressure vessel and the shielding wall is improved, so that thermal stress is reduced and deterioration can be prevented.
Also, the temperature rise of the cooling air in the space between the reactor pressure vessel and the shielding wall is low, and the high temperature air in the high temperature area does not diffuse into the reactor containment vessel, so the temperature in the dry well is equalized and the cooling device is made smaller. There is an effect that can be realized.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a main part in a reactor containment vessel according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view of a main part in a conventional reactor containment vessel. 1 ... Reactor pressure vessel 3 ... Shielding wall 4 ... Reactor containment vessel 5 ... Space section 7, 7a, 7b ... Air supply duct 8 ... Local cooler 8a ... Suction port 9 ... Nozzle 10 ... … Aperture 11 …… Dehumidifier 12a, 12b …… Air supply nozzle

Claims (1)

[Claims] 1. A dehumidifier for preventing dew condensation is connected to a local cooler installed in a drywell in a reactor containment vessel, and an air supply duct for blowing cold air cooled by the dehumidifier to a high temperature area of the drywell is connected. A cooling device in a reactor containment vessel characterized by the following.