JPH02296199A - Water supply for nuclear power station - Google Patents

Abstract

PURPOSE:To streamline a sump, a sump pump and a pump discharge piping necessary for draining and a power source for equipment by providing a water collection means on a flow surface of an equipment installed chamber while rain water or the like built up at the water collection means flows down to an intake device. CONSTITUTION:In a method of treating a drain, rain water or the like is col lected to a water collection recess 16 provided on a floor of an equipment installed chamber 10. A check valve 18 provided on a pipe 17 connected to the bottom of the water collecting recess 16 is opened in the direction of draining to let water flow freely so that a drain of the rain water or the like can flow down a seawater intake tank 14 by a dead load thereof. A lonsitudinal length of the water collecting recess 16 and the pipe 17 is a thickness of the floor 13 enough at its maximum. When a set level of equipment 12 vital in safety is exceeded with a rise in a water level of a seawater intake tank 14 when it is attacked by a tidal wave, the check valve 18 can protect the set area from the entry of the tidal wave.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to water intake equipment for a nuclear power plant without a roof for the purpose of treating wastewater such as rainwater.

(Conventional technology) In the water intake equipment of a nuclear power plant without a roof, when equipment important for safety is installed below the level of a tsunami caused by an earthquake, it is necessary to collect rainwater directly into the water intake tank in order to prevent equipment from flooding due to a tsunami. It is not possible to drain the water, so a sump is installed and a pump is used to drain the water.

Safety-important equipment installed in equipment installation rooms of water intake facilities is required to maintain its functionality even in the event of a tsunami caused by an earthquake.

Conventionally, this type of water intake equipment has been used to treat wastewater such as rainwater that is connected to the concrete equipment installation room 1, which is dug underground from the site level of the nuclear power plant site, as shown in Figure 4. A water collection sump 2 is provided for this purpose. In addition, a seawater intake tank 4 is located below the floor 3 of the equipment installation room 1.
is installed, and the water in this water intake tank 4 is sent to, for example, core cooling equipment. A sump pump 5 and a pump discharge pipe 6 are installed in the water collection sump 2. Furthermore, equipment 7 important for safety is installed on the floor of the equipment installation room 1, and other power supply equipment and control equipment for the drainage equipment are required.

(Problems to be Solved by the Invention) Conventional water intake equipment for nuclear power plants has the following problems.

(1) Since the area (floor 3) where the equipment 7 important for safety is installed is outside without a roof, rainwater flows into the area, hindering maintenance of the equipment 7 and accelerating damage.

(2) The installation level of equipment 7 important for safety is lower than the site level, and rainwater etc. cannot be guided to the general drainage channel unless power is used through floor slopes, side gutters, etc.

(3) The installation level of the safety-important equipment 7 is lower than the tsunami level, and it is not possible to directly lead seawater to the water intake tank 4 and drain it by gravity.

(4) These drainage facilities not only require a large amount of equipment cost, but also require a large space to install the equipment.

The present invention has been made to solve the above problems, and includes a sump, a sump pump, pump discharge piping, and control/power supply equipment for drainage equipment used as wastewater treatment equipment for rainwater and other wastewater in areas where safety-important equipment is installed. Our objective is to provide water intake equipment for nuclear power plants that streamlines costs and reduces the installation space for these equipment.

[Structure of the Invention] (Means for Solving the Problems) The present invention provides an equipment installation room dug underground from the site level in a nuclear power plant, and a water intake tank dug underground from the floor of this equipment installation room. A water collection means is provided on the floor of the equipment installation room, a flow path is provided for rainwater etc. accumulated in the water collection means to flow down to the water intake device, and a check valve is provided in this flow path. It is characterized by becoming.

(Function) Rainwater, etc. is collected in the water collection means installed on the floor of the equipment installation room. The check valve installed in the flow path of the water collection means is normally closed due to elastic force, but when rainwater etc. flows in, the weight of the water causes the spring to contract, opening the check valve and draining water. . During a tsunami, the check valve is closed, so there is no risk of flooding.

Therefore, rainwater, etc. can flow directly into the water intake tank without causing flooding of equipment important for safety due to a tsunami.

(Example) An example of water intake equipment for a nuclear power plant according to the present invention will be described with reference to FIGS. 1 and 2.

In Fig. 1, reference numeral 1a indicates safety-important equipment 12 that is dug underground from the site level in site II of the nuclear power plant.
This is an equipment installation room for installing. This equipment installation room 1
A seawater intake tank 14 is provided by being dug further underground from the floor 13 of 0.

Further, as shown in an enlarged view in FIG. 2, a diagonal-shaped through hole 15 is provided in the floor 13 of the equipment installation room IO and communicates with the seawater intake tank 14. A water recess 16 is formed. A check valve 18 is provided at the lower end of this water collection recess 16 via a short pipe 17 serving as a flow path.

Accordingly, in the water intake equipment of the nuclear power plant having the above-mentioned configuration, the wastewater treatment method is to collect rainwater and the like in the water collection recess 16 provided in the floor 13 of the equipment installation room 10. Since the check valve 18 provided on the pipe 17 connected to the lower part of the water collection recess 16 opens as shown by the broken line in the drainage direction to allow water to flow freely, the drainage of rainwater, etc. is carried out by the seawater by gravity. It can be made to flow down into the water tank 14.

Note that the length of the water collection recess 16 and the pipe 17 in the longitudinal direction only needs to be equal to the thickness of the floor 13 at most. At this point, a tsunami hits and the water level in the seawater intake tank 14 rises, causing equipment 1 important for safety to
If the installation level of 2 is exceeded, the check valve 18 can prevent the tsunami from entering the installation area.

FIG. 3 is a partially enlarged sectional view of another embodiment of the present invention, and the other embodiment will be described with reference to FIG.

That is, a through hole 19 extending from the lower surface of the water collection recess 16 provided in the floor 13 having the thickness of the equipment installation room 10 such as the auxiliary equipment cooling pump area to the upper surface of the seawater intake tank 14 is provided, and the inside of this through hole 19 is A long pipe 20 is attached to the drain funnel 20, and a drain funnel 22 to which a check valve 21 is attached is provided in the upper part of the long pipe 20. The other parts are the same as those in the embodiment shown in FIG. 1, so their explanation will be omitted.

In a water intake facility with such a configuration, even if a tsunami occurs when the seawater 23 accumulated in the seawater intake tank 14 reaches the high tide height (H, W, L), the wave impact of the seawater caused by the tsunami will be It is relaxed and canceled within the long tube 20. Therefore, the check valve 21 attached to the lower end of the drain funnel 22
There is no possibility that the equipment will be damaged by the tsunami, and the tsunami can be prevented from entering the equipment installation room 10.

Other functions and effects are similar to those of the embodiment shown in FIG. 1, so their explanation will be omitted.

In this embodiment, when the check valve 21 uses the funnel 22 as a water collecting means, a valve body is provided in a guide pipe that fits into the inner diameter of the end of a riser pipe (not shown), and a coil spring is inserted from the top of the check valve 21. The coil spring is compressed by the weight of the water, and the valve body, which is hinged on one end, always opens in the same direction, allowing water to flow.

As the force for opening and closing the check valve 21, methods such as spring force and buoyancy of a float can be used. In addition to the depression 16, a side gutter, a water collection floor funnel provided in the building, etc. can also be used as the water collection means.

[Effects of the Invention] According to the present invention, drainage water such as rainwater can be allowed to fall directly under its own weight into a seawater intake tank without causing overflow due to a tsunami.

This makes it possible to rationalize the sump, sump pump, pump discharge piping, and equipment power supply that were required for drainage, reducing costs and space.

[Brief explanation of drawings]

FIG. 1 is a vertical cross-sectional view schematically showing an embodiment of water intake equipment for a nuclear power plant according to the present invention, FIG. 2 is a vertical cross-sectional view showing an enlarged main part of FIG. 1, and FIG. FIG. 4 is a vertical cross-sectional view showing an enlarged view of a main part of another embodiment of the present invention, and FIG. 4 is a vertical cross-sectional view schematically showing a water intake facility of a conventional nuclear power plant. 1.lG...Equipment installation room 2...Water collection sump 3.13...Floor 4.14...Seawater intake tank 5...Sump pump 6...Pump discharge piping 7.12...・Equipment important for safety 1...Site 5...Through hole 6...Water collection depression 7...Short pipe end...Check valve 9...Through hole 20...Long pipe 21...Check valve 22...Drain funnel 23...Seawater Figure 1 (8733) Agent Patent attorney Yoshiaki Inomata (and others)
1 person) ↓ 1 water Figure 2 □14 Figure Figure

Claims (1)

[Claims] It consists of an equipment installation room dug underground from the site level in the nuclear power plant, and a water intake tank dug underground from the floor of this equipment installation room, and a water collection means is provided on the floor of the equipment installation room. A water intake facility for a nuclear power plant, further comprising a flow path through which rainwater, etc. accumulated in the water collection means flows down to the water intake tank, and a check valve is provided in this flow path.