JPS6025759B2 - Control device for nuclear reactor emergency equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a control device for nuclear reactor emergency equipment that improves reliability against operator errors.

BACKGROUND OF THE INVENTION An emergency cooling pump is one of the emergency equipment for a nuclear reactor in a nuclear power plant, etc., and a control device for controlling start-up and shutdown of the equipment has conventionally been configured as shown in FIG.

In this figure, 1 and 2 are power lines, 11 is a normally open contact of a detector (hereinafter referred to as water level low contact) that detects when the water level in the reactor has fallen below a specified value, and 12 is a contact that detects when the reactor pressure has fallen below a specified value. A normally open contact (hereinafter referred to as a high pressure contact) of a detector that detects that the pressure has risen above a specified value; 13 is a timer; 1
4 is a relay, 15 is a circuit breaker closing circuit for starting the emergency equipment, 16 is a circuit breaker tripping circuit for stopping the emergency equipment, and 17 is a circuit for detecting the state in which the emergency equipment should be protected. Normally open contact of the detector to be detected (hereinafter referred to as protective contact),
Reference numeral 18 indicates a shield or disconnector, and 19 indicates emergency equipment, such as an emergency cooling pump. In the event of a nuclear reactor accident, either one or both of the low water level contact 11 or the high pressure contact 12 closes, but if either of them closes, the timer 1 is activated through that contact.
3 is started, the normally closed contact 13 of the timer 13
Through B, the time-limited operation of the timer 13 ends and the contact 13
The relay 14 is energized for, for example, one second until the relay 8 opens, and the normal contact 14A of the relay 14 closes.

As a result, a closing command A is issued from the shield breaker closing circuit 16 to the shield breaker 18, and the emergency equipment 19 is activated. When the protective contact 17 closes while the emergency equipment 19 is in operation, a tripping command B is issued from the insulation breaker tripping circuit 16 to the insulation breaker 18, and the emergency equipment 19 is stopped. By the way, manual switches 15A and 16A, which can be operated at the operator's discretion, are connected in parallel to the normally open twill point 14A of the relay 14 and the protective contact 17 in the breaker closing circuit 15 and the breaker tripping circuit 16, respectively. These manual switches 15A and 16A can also be used to turn on and off the breaker 18, that is, to start or stop the emergency equipment 19.

These manual switches 15 and 16 are convenient for starting and stopping the emergency equipment 19 during normal times, and for starting and stopping the emergency equipment 19 as needed after a nuclear reactor accident. If you make a mistake in operating the manual switches 15 and 16, there is a danger that it will cause serious problems.

For example, at the time of the Nukako reactor accident, the high pressure state in the reactor containment vessel generally persists for a long period of time, so the water level in the reactor is restored by the operation of the pump, which is emergency equipment 19, and after the pump is properly stopped, the water level is restored again. The timer 13 continues to be energized through the high pressure contact 12 even if the pressure decreases.

In such a case, the closing command A is not automatically issued from the breaker closing circuit 15, so the operator must press the manual switch 15.
It is necessary to operate A, but if you forget this operation, the pump will not start and you will be in trouble. There is also a risk that the manual switch 17 of the shingle breaker tripping circuit 16 may be accidentally operated to stop the pump during emergency cooling of the reactor.

This invention has been made in view of the above-mentioned points, and its purpose is to prevent emergency equipment caused by incorrect operation of a manual switch attached to a circuit breaker for starting and stopping emergency equipment. An object of the present invention is to provide a control device for nuclear reactor emergency equipment that prevents erroneous control of equipment and improves reliability.

The present invention will be explained in detail below with reference to Examples. FIG. 2 shows the configuration of a control device for a nuclear reactor emergency facility according to an embodiment of the present invention, and the difference from FIG. The two features are that they are made independent of each other, and that manual tripping of the shroud breaker 18 is prohibited when the water level is low. That is, 13
-, 13-2 are first and second timers activated by a low water level detection signal and a high pressure detection signal, respectively, and are a low water level contact 11 and a high pressure contact 12, respectively.
It is connected between power supply lines 1 and 2 via.

14-, 14-2 are operated for a certain period of time by the operation of these first and second timers 13-, 13-2, respectively.
For example, the first and second switching elements are IJ relays that are energized for only one second, and the excitation coils are the water level low contact 11, the normally closed contacts 13-B of the first timer 13-, and the pressure high Contact 12 and second timer 13
-2 normally closed contact 13-2B in series to the power line 1
, 2.

In the shingle breaker closing circuit 15, a closing command A is automatically issued to the shingle breaker 15 even if either of the first and second relays 14-, 14-2 is activated. Normally open contacts 14-, A, 14-2A of the first and second relays 14-, 14-2 are connected in parallel with the manual switch 15A. On the other hand, 20 is an IJ relay as a third switching element energized by the low water level detection signal, and each exciting coil thereof is connected between the power lines 1 and 2 via the low water level contact 11.

In the breaker tripping circuit 16, the third relay 20
The normally open contact 208 and the manual switch 16A are connected in series, and this series circuit is connected in parallel with the protective contact 17, so that only when the third relay 20 is not operating, the tripping command B by the manual switch 16A is disconnected. It is designed to be served in a container 18. With the above configuration, when the water level drops below a specified value in the event of a nuclear reactor accident, the first relay 14-, is energized for a certain period of time through the water level low contact 11 and contacts 13-, B. −,A closes,
When the closing command A is issued from the breaker closing circuit 15 to the breaker 18 and the pressure rises above the specified value, the second relay 14 is activated through the high pressure contact 12 and the contact 13-2B.
-2 is energized for a predetermined time and the contact 14-2A closes, thereby issuing a closing command A to the shingle breaker 18 in the same way.

That is, the closing command A is issued from the shingle breaker closing circuit 15 to the shingle breaker 18 separately when the water level decreases and when the pressure rises. Therefore, for example, if the water level in the reactor is restored by water injection from the pump, which is the emergency equipment 19, and the water level drops again after the shroud breaker 18 is tripped by operating the manual switch 16A, even if the pressure The second timer 13-2 continues to be energized while the high contact 12 remains closed, and even if the second relay 14-2 is not energized, the first relay 14-, is energized automatically. Nishiya breaker closing circuit 15
Since input command A is issued from , the emergency equipment 19 is activated.

Therefore, in the above case, the operator should manually press switch 15.
Even if you forget to operate A, there is no problem at all. Furthermore, after the breaker 18 is turned on and the emergency equipment 19 is activated, the third relay 20 continues to be energized through the low water level contact 11 and the contact 20B remains open until the water level has recovered. Even if the operator accidentally operates the manual switch 16A, the trip command B will not be issued from the shroud breaker tripping circuit 16 to the shingle breaker 18. As described above, according to the present invention, inconveniences such as emergency equipment not being started when it should be started or being stopped when it should not be stopped due to operation errors by the driver are not caused. The reliability of control of nuclear reactor emergency equipment can be significantly improved.

[Brief explanation of drawings]

FIG. 1 is a circuit configuration diagram of a control device for a subordinate nuclear reactor emergency facility, and FIG. 2 is a circuit configuration diagram of a control device for a nuclear reactor emergency facility according to an embodiment of the present invention. 11... Water level low contact, 12... Pressure high contact, 13-,, 13-2... First and second timer, 14-,, 14-2... Number 1 and 2nd relay (switching element), 15..... breaker closing circuit, 16..... breaker tripping circuit, 15A, 16
A: Manual switch, 18: Disconnector, 19: Emergency equipment. Figure 1 Figure 2

Claims (1)

[Scope of Claims] 1. First and second timers that are activated by detection signals of low water level and high pressure in the reactor, respectively; first and second switching elements that are time-energized, a circuit that starts the reactor emergency equipment by each operation or manual operation of the first and second switching elements, and a circuit that starts the reactor emergency equipment by the low water level detection signal A nuclear reactor emergency system comprising: a third switching element that is energized when the third switching element is inactive; and a circuit that stops the reactor emergency equipment by a manual shutdown operation of the third switching element when the third switching element is not in operation. Equipment control device. 2. The first and second timers are connected to a power source through a water level low contact and a pressure high contact, respectively, which are closed by detection signals of a low water level and a high pressure in the reactor;
The first and second switching elements each have their excitation coils connected to a power source through a water level low contact, a normally closed contact of the first timer, and a pressure high contact and a normally closed contact of the second timer, respectively, in series. A nuclear reactor emergency system according to claim 1, wherein the first and second relays are a third relay, and the third switching element is a third relay whose excitation coil is connected to a power source via a water level low contact. Equipment control device.