JPS6117319B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a nuclear reactor cooling system that operates when a nuclear reactor is shut down or in the event of a nuclear reactor accident to send cooling water to the nuclear reactor to cool the reactor.

Generally, a nuclear reactor is equipped with a reactor cooling system that operates in the event of an accident or shutdown to cool the reactor. It consists of a suppression pool installed below the reactor, these water storage tanks, a cooling water transfer pump for supplying the cooling water in the suppression pool to the reactor, and piping to connect each of these devices. ing.

In normal cases, the cooling water in the water storage tank is supplied into the reactor, and when the water level in the water storage tank falls below a set value, the water in the suppression pool is switched to the nuclear reactor by switching a valve. It is designed to supply the furnace.

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However, in such a reactor cooling system, if the piping connecting the water storage tank and the reactor is damaged during an earthquake, water will not be supplied to the reactor until the water level in the water storage tank falls below the set value. Not only will it not be possible to supply cooling water, but there is also a risk that the cooling water transfer pump will be damaged. Therefore, even if the water source is switched to the suppression pool, there is a risk that the cooling function of the reactor will stop. There was also the problem that the reactor's cooling function would stop until the switch was made. In view of this, an object of the present invention is to provide a nuclear reactor cooling system in which the cooling function of the reactor does not stop during normal times or during earthquakes.

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

1 to 3, a reactor containment vessel 3 is placed in the center of a reactor building 1, a reactor pressure vessel 4 is housed within this reactor containment vessel 3, and a suppressor is placed in the lower part of the reactor containment vessel 3. A swimming pool 2 is provided.

On the other hand, a water storage tank 5 is provided outside the reactor building 1, and a water pipe 6 connects the water storage tank 5 and the reactor pressure vessel 4, with one end of the water pipe 6 being connected to the reactor pressure vessel 4. The other end of the water pipe 7 is connected to the water pipe 2, and a cooling water transfer pump 8 is installed downstream of the branch point P thereof.

An electric valve 9 and a check valve 10 are installed between the branch point P of the water pipe 6 and the water storage tank 5, and a check valve 11 and an electric valve 12 are installed on the water pipe 7, and furthermore, the water pipe 6 is cooled. A check valve 13 and a gate valve 14 are provided between the water transfer pump 8 and the reactor pressure vessel 4.
and check valves 15 are installed in order from the cooling water transfer pump 8 side.

On the other hand, at appropriate locations on the floor within the reactor building 1,
Four earthquake sensing devices 16, 16...16 are attached. These earthquake sensing devices 16 are connected to a water source change setting device 19, and the water source change setting device 19 is connected to an electric valve 9 attached to the water pipe 6 by a signal circuit 17, and the electric valve 12 is connected to a signal circuit 18. These earthquake sensing devices 1
6. Water source change setting device 19 and electric valves 9, 12
forms the seismic safety device M.

Next, the effect will be explained.

The nuclear reactor cooling system of the present invention is started manually or automatically by a signal within the nuclear power plant, and uses water in a water storage tank 5 normally installed outdoors as a water source,
A cooling water transfer pump 8 attached to the water pipe 6 guides water in the water storage tank to the reactor pressure vessel 4 through the water pipe 6 . At this time, water pipe 6
Each valve attached to the water pipe 7 is opened by remote control, and each valve attached to the water pipe 7 is closed. Then, when the water level in the water storage tank 5 becomes lower than the set value, the electric valve 9 is closed, and the electric valve 12 and check valve 11 are opened, so that the supply of water in the water storage tank is stopped. Water from the suppression pool 2 is supplied to the reactor pressure vessel.

However, when an earthquake occurs, the earthquake sensing device 16 senses the magnitude of the seismic motion as shown in FIG. 4, and the signal is sent to the water source change setting device 19. In this water source change setting device 19, a water source change setting value B is set in advance, and here, the magnitude A of the seismic motion detected by the earthquake sensing device and the water source change setting value B are compared. If A<B, priority is given to control based on the set value of the water level in the water storage tank 5, and for example, the electric valve 9 remains open and the electric valve 12 remains closed. Water from the water storage tank 5 is then sent to the reactor pressure vessel 4 as in the normal case. A≧
If it is B, the control based on the set value of the water level in the water storage tank 5 is canceled. Then, electric valve 9 is closed and electric valve 1 is closed.
2 is forcibly controlled to be open, and water from the suppression pool 2 is sent to the reactor pressure vessel 4.

Note that the electric valves 9 and 12 can of course be air-operated valves. It is also possible to design the water storage tank 5 and the water pipes with normal strength.
Further, after confirming the soundness of the water pipe 6 and the water storage tank 5, the water source can be manually switched to the water storage tank 5.

Since the present invention is configured as described above, even if an earthquake occurs that destroys the portion of the water pipe 6 between the water storage tank 5 and the reactor building 1, the reactor pressure vessel 4 is normally cooled and the reactor Driving safety is maintained. Moreover, there is no need to design the water pipes outside the reactor building 1 and the water storage tank 5 to be unnecessarily strong, and the way to support them is simple, reducing the construction cost of the entire reactor cooling system and speeding up the construction process. It is possible to shorten the time.

[Brief explanation of the drawing]

Figure 1 is a schematic configuration diagram of a nuclear reactor cooling system according to the present invention, Figure 2 is a vertical cross-sectional view of a reactor building, and Figure 3 is
A cross-sectional view of the reactor building and FIG. 4 are flow diagrams for explaining the operation of the present invention. 1...Reactor building, 2...Suppression pool, 4...Reactor pressure vessel, 5...Water storage tank, 6...Water pipe, 7...Water pipe, 8...Cooling water transfer pump, 9, 12...Electric valve, 16...Earthquake sensing device, 19...Water source change setting device. 〓〓〓〓〓

Claims (1)

[Claims] 1. A reactor building, a reactor containment vessel installed within the reactor building, a reactor pressure vessel housed within the reactor containment vessel, and a reactor pressure vessel provided below the reactor containment vessel. a suppression pool, a water storage tank provided outside the reactor building, a first water pipe led out from the water storage tank, penetrating the reactor building and reaching the upstream side of the first valve;
a second water pipe led out from the downstream side of the first valve and connected to the suction side of the cooling water transfer pump; and a second water pipe led out from the discharge side of the cooling water transfer pump and penetrating the reactor containment vessel and connected to the reactor a third water pipe that opens into the pressure vessel; a fourth water pipe that has one end open to the suppression pool and is connected to the second water pipe via a second valve; and the reactor pressure vessel. When supplying cooling water to the water storage tank, the first valve is opened and the second valve is closed, and cooling water is supplied from the water storage tank.
A nuclear reactor cooling system comprising a control device that closes a first valve and opens a second valve to supply cooling water from the suppression pool when the water level in the water storage tank drops below a set value. A plurality of earthquake sensing devices installed in the reactor building and a signal from this earthquake sensing device are input, and if the magnitude of this signal is larger than a preset water source change setting value, a close signal is sent to the first valve. and a water source change setting device that outputs an open signal to the second valve, wherein the close signal and the open signal are prioritized over the control based on the water level of the water storage tank. Device.