JPS5926920B2 - Control device for nuclear reactor emergency equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a control device for emergency equipment in a nuclear reactor.

Emergency water injection equipment is an emergency equipment for nuclear reactors.

This emergency water injection equipment is used to prevent reactor water supply loss or
This equipment is installed to maintain the cooling water inside the reactor in normal condition by injecting water into the reactor in the event of a small rupture accident.

Incidentally, such emergency water injection equipment is usually configured such that its operation can be started and stopped automatically or manually.

In other words, if a nuclear reactor rupture accident occurs,
A drop in the cooling water level in the reactor is detected, and this detection signal automatically operates the emergency water injection equipment, but even when the reactor is in normal operating condition, e.g. When conducting an operational test of the emergency water injection equipment, an operator can manually start operation of the emergency water injection equipment.

FIG. 1 is a circuit diagram showing an example of conventional control that performs the above-mentioned control.
This is a normally open contact that automatically closes in response to a signal detecting an abnormal drop in the cooling water level in the reactor. When this contact S1 closes,
Power is supplied to the timer relay 2 from the power line "1t" 2, and the normally open contact 2S is closed for a preset time.

As a result, the operation command circuit 3 outputs an operation command signal to start the operation of the emergency water injection equipment (not shown), and the emergency water injection equipment operates continuously from this point on based on this operation command signal.

When the emergency water injection operation is completed and the reactor returns to normal state, the contact S2 is automatically closed and the stop command circuit 4 is activated to stop the first drive of the emergency water injection equipment. Outputs a stop command signal.

This automatically stops the water injection operation in an emergency.

On the other hand, in addition to the automatic operation start control and stop control as described above, if the operator turns on the manual operation switch S3,
When the operation command circuit 3 is activated and the manual stop switch S4 is turned on, the stop command circuit 4 is activated, and similarly to the above, operation start control and stop control of the emergency water injection equipment can be performed.

In this manner, the conventional control means allows the emergency equipment to be started and stopped manually.

However, even when performing manual stop control, there is a high possibility of erroneous operation, as it is an operation that involves simply turning on one switch, that is, one action, just like when starting operation manually.

In other words, if the above-mentioned rupture accident occurs in a nuclear reactor,
If an operator accidentally operates the manual stop switch S4 while the emergency water injection equipment is operating, this alone will stop the emergency water injection equipment, resulting in a serious accident. It could become a problem.

As described above, with the conventional control means, even when the emergency water injection equipment is operating, the operation of the emergency equipment can be easily stopped, which poses a problem in terms of safety.

This invention was made in view of the above points, and when an accident occurs in a nuclear reactor and the emergency equipment is operating, at least two conditions must be met in order to manually stop the emergency equipment. The purpose of the present invention is to provide a control device for nuclear reactor emergency equipment that can greatly contribute to the safety of a nuclear reactor by controlling it so that it does not shut down and preventing erroneous operation.

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

In FIG. 2, 10 is a relay, one end of which is connected to the power line L1 via the same normally open contact S1 as shown in FIG. 1, and the other end is connected to the other power line L1.
Connected to 2.

The relay 10 has first and second normally open contacts 10al, 10
a2 and a normally closed contact 10b, and one end of the first normally open contact 10a1 is connected to the power supply line L1, and the other end is connected via the same timer relay 2 as shown in FIG. and is connected to the power supply line L2.

Then, this first normally open contact 10a1 and the timer relay 2
The connection point P1 is connected to the power supply line L2 via the normally open contact 2a of the timer relay 2 and the same operation command circuit 3 as shown in FIG.

Connection point P2 between this operation command circuit 3 and the normally open contact 2a
is connected to the power supply line L0 via the manual operation switch S3 shown in FIG.

Further, one end of the normally closed contact 10b of the relay 10 is connected to the power supply line L1 via the manual stop switch S4 shown in FIG. 1, and the other end is connected to the stop command circuit 4 shown in FIG. It is connected to the power supply line L2 via the power supply line L2.

The connection point P3 between the stop command circuit 4 and the normally closed contact 10b is connected to the power supply line L via the contact S2 shown in FIG.
Connected to 1.

The second normally open contact 10a2 of the relay 10 has one end connected to the power line L1, and the other end connected to the normally open contact S5, which will be described later, a manual stop permission switch S6, and the relay 12.
It is connected to the power supply line L2 via.

This relay 12 has three normally open contacts 12a1, 12a2 and 12a3, and the first normally open contact 12a1 is connected to the relay 10.
The second normally open contact 12a2 is connected between both ends of the manual stop permission switch S6.

Further, the third normally open contact 12a3 of the relay 12 has one end connected to the power supply line L1, and the other end connected to the alarm generation circuit 13.
It is connected to the power supply line L2 via.

By the way, the normally open contact S5 is a contact that closes when the emergency equipment is operating according to a command from the operation command circuit 3.

Next, the invention constructed as described above will be explained in detail.

First, it is assumed that each contact is in a state as shown in FIG. 2 as an initial state.

In such a state, if a nuclear reactor rupture accident occurs and an abnormal drop in cooling water is detected, this detection signal automatically closes the normally open contact S1 and operates the relay 10. First and second normally open contacts 10a1, 10
a2 is closed, and normally closed contact 10b is opened.

As a result, the timer relay 2 operates and closes the contact 2a for the set time.

When this contact 2a closes, the operation command circuit 3 operates and outputs an operation command signal to the emergency water injection equipment (not shown).

When the above emergency water injection equipment receives this operation command signal,
Start water injection into the reactor.

When the water injection operation is completed and the reactor returns to a normal state, the close circuit S2 is automatically closed, the stop command circuit 4 is activated, and a stop command signal is output to stop the operation of the emergency water injection equipment. do.

This automatically stops the water injection operation in an emergency.

By the way, during the operation of the emergency water injection equipment during the above-mentioned nuclear reactor emergency, it may be necessary to stop the water injection operation for some reason.

The stopping operation in such a case will be explained below.

In this case, first, the manual stop permission switch S6 is turned on.

As a result, the relay 12 operates, and its first to third normally open contacts 12a1 to 12a3 are closed, and the relay 12 is self-held by the normally open contact 12a2 being closed.

In this state, when the manual stop switch S4 is turned on, the stop command circuit 4 is activated and a stop command signal is output, and this command signal stops the operation of the emergency water injection equipment.

In this way, to stop the operation of the emergency water injection equipment while it is operating, first press the manual stop permission switch S.
6 and then the manual stop switch S4, which can prevent the operation of the emergency water injection equipment from being inadvertently stopped.

Note that if an operation is performed to stop the emergency water injection equipment while it is in operation, the alarm circuit 13 is activated to issue an alarm to alert the operator.

On the other hand, if you want to operate the emergency water injection equipment on a trial basis when the emergency water injection equipment is not operating, that is, when the reactor is working normally, you must start and stop the operation manually. You can also do it.

That is, to start operation, press the manual operation switch S.
3, the operation command circuit 3 operates, outputs an operation command signal, and operates the emergency water injection equipment.

In addition, if the operation is to be stopped in this state, by turning on the manual stop switch S4, the stop command circuit 4 is activated and outputs a stop command signal, thereby stopping the operation of the emergency water injection equipment.

As described above, in this invention, when a breakage accident or the like occurs and the emergency water injection equipment is in operation, manual operation to stop the operation can be performed by first turning on the manual stop permission switch S6 and then turning on the manual stop switch S4. In addition, when the reactor is operating normally and the emergency water injection equipment is manually started and stopped for purposes such as operation tests, both Operation start and stop control can be performed with a single operation.

In addition, in this invention, when a rupture accident occurs in the reactor and the emergency water injection equipment is activated, the contact S5 closes, so when the contact S is closed, a rupture accident or the like occurs in the reactor. You can now check what you are doing.

In the above embodiment, as a means for stopping the operation of the emergency water injection equipment when a nuclear reactor rupture accident occurs and the emergency water injection equipment is operating, the manual shutdown permission switch is first activated in the first step. However, this does not have to be a manual switch; for example, a contact that detects a temperature change that occurs during an accident and operates based on this detection signal may be used.

Further, in the above embodiment, the operation for shutting down is performed in two stages, but it goes without saying that it may be performed in three or more stages.Furthermore, this invention can be applied to emergency equipment other than emergency water injection equipment. It is.

As explained above, according to the present invention, when an accident occurs in a nuclear reactor and the emergency equipment is in operation, if it is necessary to stop the operation of the emergency equipment for some reason, at least Since the control is such that it is shut down only when two or more conditions are eliminated, it is no longer easy to shut down the emergency equipment in the event of a reactor accident, and this control of the reactor emergency equipment can greatly contribute to safety. equipment can be provided.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram schematically showing an example of a conventional control device for emergency equipment, and FIG. 2 is a circuit diagram schematically showing an example of a control device for emergency equipment according to an embodiment of the present invention. . Meter: Operation command circuit, 4: Stop command circuit, 10.12: Relay, S3:
Manual operation switch, S4...Manual stop switch, S6...Manual stop permission switch.

Claims (1)

[Scope of Claims] 1. An operation command circuit and a stop command circuit that issue operation commands and stop commands to emergency equipment of a nuclear reactor, and automatic operation of the operation command circuit and stop command circuit by detecting the state of the reactor. means for actuation by a switch that opens and closes automatically;
A means for activating the operation command circuit and the stop command circuit by operating a switch that can be manually opened and closed; When the manual switch that manually activates the stop command circuit and at least one other manual switch are both turned on during the operation of the emergency equipment during normal operation of the reactor, the stop command circuit is activated. 1. A control device for a nuclear reactor emergency facility, characterized by comprising a means for activating it. 2. The means for activating the stop command circuit using a manual switch during the operation of the emergency equipment in the case of an emergency in the above-mentioned reactor is a first manual switch connected in series with a relay contact that is closed when the above-mentioned reactor is normal and opened during an emergency. a switch, and a second manual switch connected in parallel with the relay contact, and a stop command circuit is activated when at least one of the relay contact and the second manual switch and the first manual switch are both turned on. A control island for a nuclear reactor emergency facility according to claim 1, which is a device for operating a nuclear reactor emergency facility.