JPH04253000A - Nuclear power station, its power equipment within plant and power control panel within plant - Google Patents

Abstract

PURPOSE:To receive easily the supply of emergency power from the adjacent nuclear power station when the situation of start-up failure of an emergency power source falls on the situation of loss of an external power in a nuclear power station. CONSTITUTION:Power bus bars 16a, 16b of several emergency power sources of adjacent nuclear power station are each other connected through a direct connection circuit 19, and switching measures 18a, 18b to make release and cutoff of this connection circuit 19 are set up. When situations of the external power loss and startup failure of the emergency power occur, the power supply is easily received without changing the existing interlock circuit by shutting the switching measures 18a, 18b and directly connecting the emergency bus bar of the self-occurrence side to the emergency bus bar of the adjacent nuclear power station with the connection circuit 19.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a nuclear power plant, and more particularly to a nuclear power plant suitable for securing emergency power in the event of a loss of external power when another nuclear power plant exists in an adjacent area.

0002

[Prior art] Power bus of emergency power supply of nuclear power plant (
Hereinafter, this is referred to as an emergency bus. ) are basically provided independently for each plant and for each emergency power source. Figure 6 shows
FIG. 1 is a single-line connection diagram of an in-station power supply for a nuclear power plant having two nuclear reactors. The generator on one nuclear reactor side is 4a, and the generator on the other nuclear reactor side is 4b. Each generator 4a, 4b
The outputs of are connected to a power transmission line 1 via circuit breakers 3a and 3b, respectively, and the power transmission lines 1 are mutually connected at a switchyard bus 2. The in-house power supply for each power station is obtained from the in-house generator during normal operation of the nuclear reactor, and the output of the generators 4a and 4b is provided by the in-house transformer 7a,
7b, and are connected to common buses 10a and 10b in each location via power receiving circuit breakers 8a and 8b. Common bus bar 10a,
10b is provided for each system in each power plant, and therefore power receiving circuit breakers 8a and 8b are also provided for each system. Further, each of the regular busbars 10a and 10b is connected to the emergency busbar 1 via regular/emergency busbar connection circuit breakers 12a and 12b and emergency bus power receiving circuit breakers 14a and 14b for each system.
6a, 16b, this emergency bus bar 16a, 16
Diesel generators 20a and 20b, which are emergency power sources, are connected to the power supply terminals b via power reception circuit breakers 17a and 17b, respectively. A plurality of these emergency diesel generators 20a, 20b are provided in each power generation plant, usually three (two of each are shown in FIG. 6). Furthermore, in the power supply system shown in FIG. The common bus 11 is connected to the common bus 10a of each plant,
10b via common/service bus bar communication interrupters 15a and 15b, respectively.

During normal operation of a nuclear power plant, part of the electric power from generators 4a and 4b is transferred to in-house transformers 7a and 4b.
7b, power receiving circuit breaker 8a, 8b, common bus bar 10a, 10b
The emergency bus 1 is
6a and 16b receive power (each circuit breaker is closed).
Various types of equipment (not shown) connected to the emergency buses 16a and 16b, such as equipment for keeping the reactor water level constant, are operating. When starting up a nuclear power plant,
Power from the power transmission line 1 is transferred to the service buses 10a and 1 via the starting transformer feeder circuit breaker 5, the starting transformer 6, the starting transformer power receiving circuit breaker 9, the common bus 11, and the common/service bus connection breaker 15.
Power is supplied to the emergency buses 16a, 16b, and the power from the regular buses 10a, 10b is supplied to the circuit breaker 12a, 16b.
, 14a.

[0004] Now, if a situation occurs in which the generator 4a trips, and an accident occurs on the power transmission line 1 at the same time (hereinafter, this state will be referred to as a loss of external power supply), the emergency bus 16a will be disconnected. Power supply is cut off. However, the equipment connected to the emergency bus bar 16a needs to ensure operation even in such a state. Therefore, when a loss of external power is detected, in the case of FIG. 6, the two emergency diesel generators 20a are automatically started, and the diesel power receiving circuit breaker 17a is automatically closed, and each diesel generator 20a is activated automatically. The generated power is supplied to the emergency bus 16a of each system. Incidentally, when the external power supply is lost, the circuit breaker 14a that connects the emergency bus bar 16a and the regular bus bar 10a is automatically shut off.

[0005] As related to the prior art, there is, for example, Japanese Patent Laid-Open No. 62-228997.

[0006]

[Problems to be Solved by the Invention] In the above-described nuclear power plant configuration, if the emergency diesel generator fails to start when external power is lost, the power bus 16a of the emergency diesel generator will experience a power outage. Power supply to the devices connected to the bus bar 16a is stopped. It is desirable for nuclear power plants to have a configuration that ensures safety, but in case of emergencies that may occur several times during the life of the reactor, a large emergency diesel generator weighing around 100 tons is required. Providing a backup for each emergency diesel generator would be a waste of space and cost. However, for safety reasons, it is necessary to take measures against accidents that rarely occur.

[0007] As a countermeasure to this problem, it is conceivable to configure a similar emergency diesel generator at an adjacent nuclear power plant to be on standby as a backup. Looking at the power supply system diagram in FIG. 6, the output of the emergency diesel generator 20b of the adjacent nuclear power plant is transmitted to the power supply bus 16 of the emergency diesel generator 20a via various circuit breakers and the regular bus.
It is possible to connect to a. However, although it is possible in principle to supply power from an emergency diesel generator of another nuclear power plant to an emergency bus that requires power via this connection route, there are the following problems. In other words, various types of circuit breakers have various interlock conditions set for normal operation and other situations, and it is necessary to rearrange these conditions to set new interlock conditions. or,
It is assumed that the above-mentioned external power loss occurs when a major earthquake or the like occurs, but when such a situation occurs, emergency power is supplied using the regular bus 10 or the common bus 11 as a route. does not make much sense in terms of safety measures. This is because the structure of the turbine building, which houses the service busbar and common busbar, is relatively weak compared to the reactor building, which has seismic design and other safety features that are many times more stringent than normal building standards. be.

An object of the present invention is to provide a nuclear power plant that can use emergency power from an adjacent nuclear power plant for backup without changing the conventional interlock conditions and without going through the turbine building. It is about providing.

[0009]

[Means for Solving the Problems] The above object is to provide a power supply bus for the emergency power supply installed in each reactor equipment in a nuclear power plant equipped with at least two nuclear reactors each having a plurality of emergency power supplies. is a communication circuit that directly electrically communicates between each reactor equipment, and a switching means that opens and closes the communication circuit. Achieved by providing a switching means for connecting the power bus of the emergency power source on the other reactor side to the power bus of the emergency power source whose startup has failed through the connection circuit when the emergency power source fails to start. be done.

0010

[Operation] Using Figure 6 as an example, normal interlock conditions are determined considering the flow of power from the power transmission line side to the emergency bus side, and vice versa, from the emergency bus side to the power transmission line side. It is not assumed that electricity will be supplied to Therefore, in order to create a configuration that takes in power from the emergency power source of the neighboring nuclear power plant via the regular bus or common bus, the flow of power on the power sending side must be from the emergency bus to the regular bus. Therefore, the interlock conditions must be changed as described above.

However, in the present invention, since the emergency buses are directly connected by a communication circuit, there is no need to change the interlock conditions. In addition, since the communication circuit directly connects nuclear power plants, and the switching means can be installed in the control panel of the reactor building, it is possible to use only buildings with extremely high safety standards, and in case of an emergency This is sufficient as a safety measure.

0012

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a single-line connection diagram of an in-house power supply for a nuclear power plant according to an embodiment of the present invention, and the same parts as those in FIG. 6 are given the same reference numerals and the explanation thereof will be omitted. In the power generation plant according to the embodiment of the present invention, the emergency bus bar 16a of each system of each nuclear power plant is directly connected to the emergency bus bar 16b of each system of an adjacent nuclear power plant for each system by the communication circuit 19. In the middle of each communication circuit 19, there is a busbar communication breaker 18a.
, 18b are provided, and by opening and closing the circuit breakers 18a and 18b, the corresponding communication circuit 19 is opened and connected. The circuit breakers 18a and 18b are attached to the emergency power control panel of each nuclear power plant, and in this embodiment, they are opened and closed manually. In addition, it is also possible to open and close this automatically.

FIG. 2 is a detailed configuration diagram of the communication circuit shown in FIG. 1. Power receiving circuit breaker 1 for the nuclear power plant on the left
An emergency bus bar 16a is connected to a regular bus bar 10a (FIG. 1), not shown, through a bus 4a, and an emergency bus bar 16a is connected to a regular bus bar 10b, not shown (FIG. 1), via a power receiving circuit breaker 14b for the nuclear power plant on the right side. 16b means bus circuit breaker 1
8a and 18b and are directly connected via a communication circuit 19. The voltage of the emergency bus 16a is input to an undervoltage relay 37a and a voltmeter 38a via a voltage transformer 36a, and when the voltage does not reach a predetermined value, the undervoltage relay 37a operates and an annunzeta (ANN) is activated. ) 39a operates. In addition, the emergency bus bar 16a is equipped with a power receiving circuit breaker 17a.
A diesel generator 20a as an emergency power source is connected through the generator 20a, and the output of the generator 20a is inputted to a voltage relay 41a, a voltmeter 30, and a frequency meter 31a through a voltage transformer 29a. It has become. The emergency bus bar 16b on the right side has a similar configuration, and the same components as the configuration on the left side described above are given the same numerals as "b", and the description thereof will be omitted.

Under normal operating conditions, the circuit breaker 14a is in the closed state, the circuit breaker 17a is in the open state, and the circuit breakers 18a and 18b are in the open state.
is in a free state. Suppose now that an external power loss situation occurs at the nuclear power plant on the left. When the external power supply is lost, the voltage of the emergency bus 16a decreases, and when it falls below a predetermined voltage value, it is transmitted to the voltmeter 38 via the voltage transformer 36a.
a, and the operator can recognize it by monitoring it. The operator can also recognize the occurrence of such a situation by operating the undervoltage relay 37a due to the voltage drop and by causing the annunzer 39a to issue an alarm.

On the other hand, when the undervoltage relay 37a operates, the interlocked control means shown in FIG.
6a is cut off from the regular bus 10a side, and the diesel generator 20a is started. When the startup of the diesel generator 20a is completed and its output increases to reach a predetermined voltage value, the control means with the interlock shown in FIG. 4 operates, the voltage relay 41a operates, and the power receiving circuit breaker 17a is closed, and the power generated by the diesel generator 20a is transferred to the emergency bus 1.
6a.

[0016] If diesel generator 20a fails to start, the output voltage of generator 20a will not increase, and therefore voltage relay 41a will not operate. Therefore, the power receiving circuit breaker 17a remains in the open state. Furthermore, failure to start the generator 20a is known to the operator who monitors the voltmeter 30 and frequency meter 31a. In this state, the circuit breaker 14a
is in the open state and the undervoltage relay 37a is in the operating (open) state. According to the interlock shown in FIG. Bus bars 16a and 16b are electrically connected. Thereby, electric power is supplied to the emergency bus bar 16a from the nuclear power plant on the right side. If the nuclear power plant on the right is operating normally, emergency bus 1
6b is supplied with the output power of the generator 4b of the nuclear reactor. Further, when the nuclear reactor is stopped, power is supplied from the power transmission line 1 side to the emergency bus bar 16b. If a loss of external power occurs at the nuclear power plant on the right, diesel generator 2, which is an emergency power source,
0b is activated, and power from this diesel generator 20b is supplied to the emergency bus 16a.

[0017]

[Effects of the Invention] According to the present invention, even if an external power source is lost and the emergency power source fails to start, it can be handled without changing the conventional interlock circuit and at a reduced cost. This will further improve the safety of nuclear power plants.

[Brief explanation of the drawing]

FIG. 1 is a single-line connection diagram of an in-station power supply of a nuclear power plant according to an embodiment of the present invention.

FIG. 2 is a detailed configuration diagram around the communication circuit shown in FIG. 1;

FIG. 3 is an interlock block diagram for automatically starting the emergency power supply by operating an undervoltage relay.

FIG. 4 is an interlock block diagram for disconnecting the emergency power receiving circuit breaker when the emergency power supply fails to start.

FIG. 5 is an interlock block diagram for a communication circuit breaker between emergency busbars at adjacent nuclear power plants.

FIG. 6 is a single-line connection diagram of the in-station power supply of a conventional nuclear power plant.

[Explanation of symbols]

1...Power transmission line, 4a, 4b... Generator for nuclear reactor, 10a,
10b... Regular bus bar, 14a, 14b... Emergency bus power receiving circuit breaker, 16a, 16b... Emergency bus bar, 17a, 17b...
Emergency power receiving circuit breaker, 18a, 18b...Emergency bus connection breaker, 19...Communication circuit, 20a, 20b...Emergency diesel generator.

Claims (7)

[Claims] Claim 1: In a nuclear power plant equipped with at least two nuclear reactors each having a plurality of emergency power supplies, the power supply busbar of the emergency power supply installed for each reactor equipment is electrically connected between each reactor equipment. a communication circuit that directly communicates with
It is a switching means that opens and closes the communication circuit, and when a situation occurs in which the emergency power source is activated on one reactor side and the activation of the emergency power source on the reactor side fails, the emergency power source on the other reactor side is activated. A nuclear power generation plant characterized by comprising: opening/closing means for connecting the power bus of the power source to the power bus of the emergency power source that has failed to start up through the communication circuit. 2. In a nuclear power plant comprising at least two nuclear reactors each having a plurality of emergency power sources, the power bus of the emergency power sources installed for each reactor equipment is connected between each reactor equipment. a communication circuit that directly communicates with
A switching means for opening/closing the communication circuit, which prevents one reactor from obtaining on-site power from the reactor's generator or power transmission line, and at least one emergency power supply on the reactor side. 1. A nuclear power generation plant, comprising: opening/closing means for connecting a power bus of an emergency power source on the other reactor side to a power bus of an emergency power source that has failed to start. [Claim 3] In a method for controlling the power supply of a nuclear power plant having multiple nuclear power plants within a predetermined area, the power supply of a nuclear power plant can be obtained from the generator of the reactor or the power transmission line. When the nuclear power plant becomes unable to operate and the emergency power source of the nuclear power plant fails to start, the power bus of the emergency power source of another nuclear power plant is directly connected to the power bus of the emergency power source that failed to start. A method for controlling the power supply within a nuclear power plant. Claim 4: In a nuclear power plant where there is another nuclear power plant in an adjacent area, a connection that directly electrically connects the power bus of its own emergency power source to the power bus of the emergency power source of another nuclear power plant. A circuit, and a switching means that closes the communication circuit and receives power from the power bus of the emergency power source of another nuclear power plant when a situation occurs in which the own emergency power source is activated and the activation fails. A nuclear power plant characterized by: Claim 5: In a nuclear power plant where there is another nuclear power plant in an adjacent area, both nuclear power plants A nuclear power generation plant comprising: a communication circuit that directly connects emergency power supply buses between stations; and an opening/closing means that closes the communication circuit during backup. [Claim 6] In the in-house power control panel of a nuclear power plant that has another nuclear power plant in an adjacent area, between the power bus of the adjacent nuclear power plant's emergency power source and the power bus of its own emergency power source. An in-house power supply control panel for a nuclear power plant, characterized in that it is provided with a switching means for opening and closing a communication circuit that directly electrically connects. 7. The busbars of the emergency power supplies installed in each of the nuclear power plants are directly connected between the nuclear power plants by a communication circuit through switching means, and the emergency power supplies of the adjacent nuclear power plants are The on-site power supply equipment of a nuclear power plant is configured so that the power from the power supply bus is kept on standby as a backup for its own emergency power supply.