JPH03194499A - Nuclear reactor containment air conditioning facility - Google Patents

Abstract

PURPOSE:To cool the entire inside sufficiently by providing a cooler which cools the gas in nuclear reactor containment, an air blower which sends gas cooled by the cooler, and a cooling gas blowing duct. CONSTITUTION:The nuclear reactor containment air conditioning facilities 20 are equipped with the cooler which produces the cooling gas and the air blower which is connected to the cooler and sends the cooling gas. The cooling gas blowing duct 21 which is connected to the air blower and extends to a lower dry well 8B is terminated having a 1st blow-out opening 22 nearby an opening, i.e. below grating 13 as one end as usual. Then the cooling gas passing through the cooling gas blowing duct 11 when entering a nuclear reactor shield wall 5 is branched partially to flow in a branch pipe 23 and the remainder is jetted to below a grating 13 from a 1st blow-out opening 24. The jetted cooling gas becomes a swivel flow along the wall surface of the unclear reactor shield wall 5 to display cooling operation entirely in the shield wall 5.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to a reactor containment vessel air conditioning system installed in a reactor containment vessel, and relates to a grating for inspecting reactor pressure vessel auxiliary equipment. The present invention relates to a reactor containment vessel air conditioning system that can provide sufficient cooling and air conditioning throughout the reactor containment vessel even if a reactor containment vessel is installed.

(Prior art) Inside the reactor containment vessel installed to house the reactor pressure vessel in a nuclear power plant, there are internal pumps, various electric motors, instrumentation, control devices, and piping outside the reactor pressure vessel. etc. are stored in large numbers. Therefore, in order to prevent the functions of these stored items from being impaired by temperature changes, reactor containment vessel air conditioning equipment is also installed inside the reactor containment vessel.

FIG. 3 is a schematic diagram of a reactor containment vessel 2 in which such a reactor containment vessel air conditioning equipment 1 is installed.

First, in the reactor containment vessel 2, a reactor shielding wall 5 is extended by providing openings 4 at several locations on a pedestal 3 that is installed at the bottom to allow pipes and cables to pass through. Then, the reactor pressure vessel 7 is stored while being surrounded and supported by the reactor shielding wall 5 and the support skirt 6 installed inside the reactor shielding wall 5. The space around the reactor pressure vessel 7 is called a dry well 8, and is normally filled with gas (air), but in the event of a loss of coolant accident, a mixture of air and water is released. The dry well 8 also includes an upper dry well 8A that surrounds the upper part of the reactor pressure vessel 7 and the upper side of the reactor shielding wall 5, and an upper drywell 8A that surrounds the lower side of the reactor shielding wall 5 and the lower part of the reactor pressure vessel 7. It is fractionated into the lower dry well 8B.

The reactor containment vessel air conditioning equipment 1 includes a cooler 9 provided in the upper dry well 8A and a blower 1 connected to this cooler 9.
0 and the upper dry well 8 connected to this blower 10.
A and a cooling gas blowing duct 11 extending to the lower dry well 8B. The cooling gas blowing duct 11 extending into the lower dry well 8B terminates near the opening 4 described above. The cooler 8 also includes a lower dry well 7B.
An air supply duct 14 that sends air taken in is connected thereto.

FIG. 4 is an enlarged schematic diagram of the reactor containment vessel air conditioning equipment 1 and the lower dry well 7B in FIG. 3. Portions corresponding to those in FIG. 3 are denoted by the same reference numerals, and explanation thereof will be omitted.

A plurality of internal pumps 12 and other important reactor pressure vessel accessories (not shown) are installed at the bottom of the reactor pressure vessel 7 and below the support skirt 6. A grating 13 is installed inside the upper end of the device 4, which serves as a foothold for inspectors to use when inspecting these devices.

In this reactor containment vessel air conditioning equipment 1, the cooler 9 cools the air taken into it and sends it to the blower 10 as cooling gas. Then, the blower 10 sends this cooling gas to the upper dry well 8A and the lower dry well 8B through the cooling gas blowing duct 11. As a result, since there are no particular obstacles in the upper dry well 8A, this cooling gas is distributed in all directions and is evenly cooled.

On the other hand, the cooling gas sent to the lower dry well 8B is discharged from the cooling gas blowing duct 11 near the opening 4, but in this way, the cooling gas that cools the inside of the reactor shielding wall 5 is discharged from the wall surface of the reactor shielding wall 5. This becomes a swirling flow that flows along the reactor shielding wall 5 below the grating 13 and evenly spreads (is scattered) inside the reactor shielding wall 5, improving cooling efficiency. When the lower dry well 8B is cooled, the air filled in the lower dry well 8B enters the air supply duct 11 and enters the cooler 9.
sent to. Thereafter, the above-described cycle is repeated to maintain air conditioning in the reactor containment vessel 2.

By the way, the grating 13 is formed into a honeycomb-shaped grating, for example, so that the cooling gas can reach the equipment located below the support skirt 6. The spacing between each grid is also made as wide as possible within the range that allows the inspector to maintain his or her footing so that the scattering of the cooling gas, which enhances the cooling effect, is not hindered.

However, the grating 13 must be thick in the vertical direction in order to maintain its strength as a scaffold for the inspector. Then, the cooling gas flows into the grating 13 from the vicinity of the opening 4 at an inclined angle, but the flow is calmed by colliding with this thick portion. As a result, only the cooling gas with low momentum reaches above the grating 13, and the equipment above the grating 13 cannot obtain a sufficient cooling effect.

The present invention has been made in view of the above circumstances, and provides a reactor containment vessel air conditioner that can exert sufficient cooling air conditioning action throughout the reactor containment vessel even if a grating for inspecting reactor pressure vessel auxiliary equipment is installed. The purpose is to provide facilities.

[Structure of the invention]

(Means for Solving the Problems) In order to solve the above-mentioned problems, the present invention provides a dry well for storing a nuclear reactor pressure vessel equipped with various auxiliary equipment, and in which a grating for inspecting the auxiliary equipment is installed. A cooler for cooling gas in the reactor containment vessel, a blower for blowing the gas cooled by the cooler, and a cooling device connected to the blower and guided to both sides of the grating. Provided is a nuclear reactor containment vessel air conditioning system that is provided with a gas blowing duct.

(Function) In the reactor containment air conditioning system of the present invention, the cooling gas ventilation duct connected to the blower is connected to one side of the grating (
In addition to terminating on the other side (upper side) of the grating ink, it also branches in the middle, passes through the grating, and terminates on the other side (upper side) of the grating ink. Therefore, according to the reactor containment air conditioning system of the present invention, the cooling gas generated by the cooler is vigorously jetted out to both sides of the grating and evenly distributed throughout the reactor containment vessel. For this reason, the reactor containment vessel is
The entire interior is sufficiently cooled.

(Example) The present invention will be described in detail below with reference to FIGS. 1 and 2.

FIG. 1 is a sectional view of a lower dry well 8B of the reactor containment vessel in which a grating 13 for inspecting attached equipment is installed. Note that portions corresponding to those in FIG. 4 are designated by the same reference numerals, and description thereof will be omitted.

The reactor containment air conditioning equipment 20 according to this embodiment includes a cooler that generates cooling gas and a blower that is connected to the cooler and blows the cooling gas, which are shown in FIGS. 3 and 4. It is not shown in FIG. 1 because it is installed in the upper drywell like conventional reactor containment vessel air conditioning equipment.

Further, as explained in FIGS. 1 and 2, the upper dry well is sufficiently cooled by the cooling gas blowing duct arranged in the upper dry well.

The cooling gas blowing duct 21 connected to the blower and extending into the lower dry well 8B terminates at one end near the opening 4, that is, below the grating 13, with the first outlet 22, as in the conventional case.

However, the cooling gas blowing duct 21 according to this embodiment branches with a branch pipe 23 inside the reactor shielding wall 5. The branch pipe 23 passes through the grating 13 and terminates above the grating 13 with a second outlet 24 . That is, the cooling gas ventilation duct 2 in this embodiment
1 are guided above and below (on both sides) of the grating 13 and terminate therein.

Therefore, in the reactor containment air conditioning system 20 of this embodiment, the cooling gas generated by the cooler and sent by the blower passes through the cooling gas blowing duct 11 to the lower dry well 8.
Guided by B. When the cooling gas passing through the cooling gas blowing duct 11 enters the reactor shielding wall 5, part of it branches into the branch pipe 23 and flows into the branch pipe 23, and the other part flows into the first outlet 24.
It is ejected from below the grating 13. The ejected cooling gas becomes a swirling flow that flows along the wall surface of the reactor shielding wall 5, and evenly spreads within the reactor shielding wall 5 below the grating 13, exerting a cooling effect.

On the other hand, the cooling gas branched into the branch pipe 23 travels upward within the reactor shielding wall 5 while passing through the branch pipe 23 and is ejected above the grating 13 from the second outlet 24 . Since the ejected cooling gas has a strong force, it spreads to every corner of the space between the grating 13 and the support skirt 6, and the internal bomb 12 and various auxiliary equipment of the reactor pressure vessel 7 disposed within this space. (not shown)
Cool thoroughly.

FIG. 2 is a diagram showing the results of cooling the lower dry well 8B using the reactor containment vessel air conditioning system 20 of this embodiment in comparison with cooling by the conventional reactor containment vessel air conditioning system. In the figure, the broken line indicates the temperature in the lower dry well 8B according to the present embodiment, and the solid line indicates the temperature when cooling is performed using a conventional reactor containment vessel air conditioning system (comparative example). As can be seen from this figure, below the grating, the cooling according to this embodiment and the cooling according to the comparative example have similar effects, and the temperatures are almost the same.

However, above the grating, when conventional reactor containment air conditioning equipment is used, the powerful cooling gas cannot pass through the grating, so a sufficient cooling effect cannot be obtained and the temperature rises. is discontinuous.

However, in this example, sufficient cooling is performed even above the grating, and the temperature is significantly lower than that of the comparative example, and the temperature is continuous above and below the grating.

Therefore, according to the reactor containment air conditioning system 20 of this embodiment, not only the upper dry well but also the lower dry well 8B are sufficiently cooled regardless of whether they are above or below the grating 13.

〔Effect of the invention〕

As explained above, in the reactor containment air conditioning system of the present invention, the cooling gas blowing duct connected to the blower not only terminates on one side (below) of the grating, but also branches in the middle and passes through the grating. It also terminates on the other side (above) of the grating. Therefore, according to the reactor containment air conditioning system of the present invention, the cooling gas generated by the cooler is vigorously jetted out to both sides of the grating and evenly distributed throughout the reactor containment vessel. Therefore, the entire inside of the reactor containment vessel is sufficiently cooled.

...Blower, 13...Grating, 21...
Cooling gas ventilation duct, 23...branch pipe.

Claims (1)

[Claims] A cooler for cooling gas in the reactor containment vessel, which stores a reactor pressure vessel equipped with various auxiliary equipment and has a dry well in which a grating for inspecting the auxiliary equipment is installed. Reactor containment vessel air conditioning equipment is provided with: a blower for blowing gas cooled by the cooler; and a cooling gas blowing duct connected to the blower and guided to both opening sides of the grating.