Nuclear reactor power supply device

Abstract

This invention provides a reactor power supply device that implements ATWS-RPT functionality using a circuit that meets the requirements for severe accident response equipment. [Solution] The system is configured such that a first-class signal is input to the first bank 7 and the second bank 8, and a second-class signal is input to the first output circuit breaker 4 and the second output circuit breaker 4. When a first-class signal is input to the first bank 7 and the second bank 8, semiconductor switches operate to interrupt the AC, and when a second-class signal is input to the first output circuit breaker 4 and the second output circuit breaker 4, they open to interrupt the AC.

Description

TECHNICAL FIELD

[0001] Embodiments of the present invention relate to a power supply apparatus for a nuclear reactor. BACKGROUND ART

[0002] Conventionally, there is a nuclear reactor power supply apparatus that controls an AC power supplied to an electric motor for driving a recirculation pump that circulates a coolant in a boiling water nuclear reactor. A nuclear reactor removes heat from the core and generates steam by forcibly circulating the coolant in a reactor pressure vessel, and adjusts the nuclear reactivity of the core and controls the plant output by changing the flow rate of the coolant. The coolant is delivered by a reactor coolant recirculation pump provided in the reactor pressure vessel, including a reactor built-in coolant recirculation pump. The nuclear reactor power supply apparatus controls and changes the flow rate of the coolant by controlling the speed of the electric motor connected to the recirculation pump.

[0003] As one of methods for controlling the speed of the electric motor of a recirculation pump, there is a method of controlling a power supply voltage and a power supply frequency by using a nuclear reactor power supply apparatus as a drive power supply apparatus for a recirculation pump. This nuclear reactor power supply apparatus includes a semiconductor conversion circuit and a speed control device. The semiconductor conversion circuit includes a forward conversion circuit for semiconductor power that converts three-phase alternating current received from an in-plant power system into direct current, and an inverse conversion circuit for semiconductor power that converts direct current into alternating current having an arbitrary frequency.

[0004] The nuclear reactor power supply apparatus is configured with two systems, each of which is a pair of a forward conversion circuit that forward-converts alternating current into direct current and an inverse conversion circuit that inverse-converts direct current into alternating current, provided in series. The electric motor of the recirculation pump may stop due to factors such as a single failure of a semiconductor element in one of the systems or maintenance and inspection of the semiconductor conversion circuit. Even when the motor stops in such a case, continuous operation can be performed by using the remaining one system. This allows the coolant in the reactor pressure vessel to be continuously circulated.

[0005] The recirculation pump controls the flow rate of the coolant circulating within the reactor, thus directly affecting the reactor output. The reactor power supply unit has a function to stop the recirculation pump's motor in the event of an abnormal reactor condition. This function is called the recirculation pump trip function.

[0006] The recirculation pump trip function has both an EOC-RPT function and an ATWS-RPT function. The EOC-RPT function is a function that stops the operation of the recirculation pump in order to suppress the rise in reactor power and maintain the integrity of the fuel rods when a turbine trip or generator load shedding occurs. Turbine trips or generator load shedding are referred to as EOC events. The ATWS-RPT function is a function that stops the operation of the recirculation pump in order to mitigate the rise in reactor pressure when the reactor pressure or reactor water level reaches a specified value in the event of a reactor abnormality in which a reactor scram does not occur. An event in which a reactor abnormality occurs in which a reactor scram does not occur is referred to as an ATWS event.

[0007] The ATWS-RPT function is required by Article 44 of the "Regulations on the Standards for the Location, Structure and Equipment of Commercial Power Reactors and Their Ancillary Facilities" to be a device that automatically stops the recirculation pump when an ATWS event occurs. Furthermore, the "Assessment Criteria for the Technical Capabilities Necessary for Power Reactor Operators to Implement Measures Necessary to Prevent the Occurrence and Exacerbation of Severe Accidents in Commercial Power Reactors" requires a device for manually stopping the recirculation pump in case it does not automatically stop. In response to these requirements, the device related to the ATWS-RPT function must be installed as a severe accident response facility (hereinafter referred to as "SA facility").

[0008] Prior to the implementation of the new regulatory standards, the ATWS-RPT function was not required as part of the SA (Safety Emergency Response) equipment. Therefore, existing reactor power supply units have common circuit elements in their operating circuits with the EOC-RPT function, and are not configured to reliably operate as SA equipment in the event of a severe accident.

[0009] Figure 1 is a circuit diagram of a conventional reactor power supply unit 100A. Before the implementation of the new regulatory standards, the configuration of the reactor power supply unit 100A had a common circuit configuration in which the EOC-RPT signal 16 and ATWS-RPT signal 17 transmitted from the reactor condition monitoring device 15 were input. For example, the EOC-RPT signal 16 and ATWS-RPT signal 17 were input to the first bank 7 and second bank 8, which control the speed of the motor 13 of the recirculation pump 14.

[0010] Figure 2 is a circuit diagram of a reactor power supply unit 100B equipped with a conventional ATWS-RPT dedicated circuit breaker 27. A dedicated circuit breaker 27, which operates in response to the ATWS-RPT signal 17, is installed in the power supply system that supplies power to the first bank 7 and the second bank 8. When this dedicated circuit breaker 27 receives the ATWS-RPT signal 17, the circuit breaker 27 opens, interrupting the power supply to the motor 13 of the recirculation pump 14. [Prior art documents] [Patent Documents]

[0011] [Patent Document 1] Japanese Patent Publication No. 2006-98399 [Overview of the project] [Problems that the invention aims to solve]

[0012] Existing reactor power supply units have common circuit elements in the operating circuits for both EOC-RPT and ATWS-RPT functions, and do not have the circuit configuration required for ATWS-RPT function as a SA (Safety Advisory) device during a severe accident.

[0013] The embodiments of the present invention have been made in consideration of these circumstances, and aim to provide a reactor power supply device that realizes ATWS-RPT functionality with a circuit that satisfies the conditions required for a severe accident response system. [Means for solving the problem]

[0014] The reactor power supply device according to an embodiment of the present invention comprises: a first bank provided between an external power source and a recirculation pump, which converts the alternating current input from the external power source into a preset voltage and frequency and outputs it to the recirculation pump; a second bank provided in parallel with the first bank and serving as a backup for the first bank, which converts the alternating current input from the external power source into a preset voltage and frequency and outputs it to the recirculation pump; a first output circuit breaker connected in series downstream of the first bank and interrupting the alternating current when open; and a second output circuit breaker connected in series downstream of the second bank and interrupting the alternating current when open, wherein the signal output from the reactor condition monitoring device when an abnormal event occurs in the reactor is transmitted to the reactor when a turbine trip or generator load shedding occurs. The system includes a first type signal that activates a function aimed at suppressing the rise in force and maintaining the integrity of the fuel rods, and a second type signal that activates a function aimed at mitigating the rise in reactor pressure when the reactor pressure or reactor water level reaches a specified value in the event that a reactor scram does not occur when the abnormal event occurs in the reactor, wherein the first type signal is input to the first bank and the second bank, and the second type signal is input to the first output circuit breaker and the second output circuit breaker, wherein when the first type signal is input to the first bank and the second bank, semiconductor switches operate to interrupt the AC, and when the second type signal is input to the first output circuit breaker and the second output circuit breaker open to interrupt the AC. [Effects of the Invention]

[0015] Embodiments of the present invention provide a reactor power supply that implements ATWS-RPT functionality in a circuit that satisfies the requirements for a severe accident response system. [Brief explanation of the drawing]

[0016] [Figure 1] A circuit diagram showing the first example of a conventional power supply unit for a nuclear reactor. [Figure 2] A circuit diagram showing a second example of a conventional power supply unit for a nuclear reactor. [Figure 3]Circuit diagram showing the nuclear reactor power supply device according to the first embodiment. [Figure 4] Circuit diagram showing the output circuit breaker according to the first embodiment. [Figure 5] Circuit diagram showing the output circuit breaker according to the second embodiment. [Figure 6] Circuit diagram showing the nuclear reactor power supply device according to the third embodiment. MODE FOR CARRYING OUT THE INVENTION

[0017] (First Embodiment) Hereinafter, embodiments of a nuclear reactor power supply device will be described in detail with reference to the drawings. First, the nuclear reactor power supply device 101 according to the first embodiment will be described with reference to FIGS. 3 to 4.

[0018] A nuclear reactor (not shown) provided with the nuclear reactor power supply device 101 is exemplified by a boiling water nuclear reactor. The nuclear reactor power supply device 101 controls alternating current supplied to an electric motor 13 for driving a recirculation pump 14 that circulates a reactor coolant. The nuclear reactor power supply device 101 varies the voltage of alternating current and also varies the frequency of alternating current. For example, the nuclear reactor power supply device 101 converts alternating current input from an external power supply (not shown) into a preset voltage and frequency, and supplies the converted alternating current to the electric motor 13. The nuclear reactor power supply device 101 is also referred to as a variable voltage variable frequency power supply device for a reactor coolant recirculation pump.

[0019] Hereinafter, severe accident response equipment as equipment with enhanced seismic resistance is referred to as "SA equipment". SA equipment is equipment whose structure is reinforced to cope with severe accidents in accordance with "Rules on the Standards for Location, Structure and Equipment of Practical Power Generation Nuclear Reactors and Their Auxiliary Facilities, Article 44". SA equipment may be installed in existing nuclear reactors, and may also be installed in newly constructed nuclear reactors.

[0020] A nuclear reactor power supply device 101 includes a portion that is a SA facility and a portion that is a non-SA facility which is not a SA facility. A SA facility is a facility whose structure is reinforced so as to have at least higher seismic resistance than a non-SA facility. For example, a non-SA facility is an existing (ordinary) facility, and a SA facility is a facility improved based on new regulations (seismic retrofitting facility).

[0021] As shown in Figure 3, the external power supply of a nuclear power plant is input from the on-site high-voltage bus 1 via the input transformer 2. The high-voltage bus 1 branches into two systems on the downstream side of the input transformer 2. Each branched system is connected to an input breaker 3. These two input breakers 3 are provided in an input breaker panel 9.

[0022] The two systems of power connected to the input breakers 3 are input to the first bank 7 and the second bank 8 while the systems are kept separated. The first bank 7 and the second bank 8 are provided on a bank electric panel 10 serving as a first electric panel. The bank electric panel 10 is composed of a PLR-VVVF or a RIP-ASD.

[0023] Of the two input breakers 3, the one connected to the first bank 7 is the first input breaker, and the one connected to the second bank 8 is the second input breaker. The first input breaker is connected in series to the upstream side of the first bank 7, and cuts off alternating current when opened. The second input breaker is connected in series to the upstream side of the second bank 8, and cuts off alternating current when opened.

[0024] The power input to the first bank 7 and the second bank 8 is output to two output breakers 4 while the systems are kept separated. That is, the two output breakers 4 receive power from the first bank 7 and the second bank 8. The two output breakers 4 are provided on an output breaker panel 11 serving as a second electric panel.

[0025] Of the two output circuit breakers 4, the one connected to the first bank 7 is the first output circuit breaker, and the one connected to the second bank 8 is the second output circuit breaker. The first output circuit breaker is connected in series downstream of the first bank 7 and interrupts AC when open. The second output circuit breaker is connected in series downstream of the second bank 8 and interrupts AC when open.

[0026] The bank electrical panel 10 has a switching function for the first bank 7 and the second bank 8. The second bank 8 is a backup for the first bank 7. The switching function for the first bank 7 and the second bank 8 is activated when a bank switching signal 22 (Figure 4) is input from a predetermined control device (not shown).

[0027] The power supply connected to the output circuit breaker 4 is connected to the motor 13 via the output transformer 12, after the two branched circuits (busbars) are joined together midway. This motor 13 is connected to the recirculation pump 14 that circulates the reactor coolant and drives the recirculation pump 14.

[0028] The reactor power supply unit 101 comprises at least two input circuit breakers 3, a first bank 7, a second bank 8, and two output circuit breakers 4.

[0029] The first bank 7 is a circuit installed between the external power supply and the recirculation pump 14, which converts the AC input from the external power supply into a preset voltage and frequency and outputs it to the recirculation pump 14.

[0030] The second bank 8 is connected in parallel to the first bank 7 and serves as a backup for the first bank 7. It is a circuit that converts the AC power input from an external power source into a preset voltage and frequency and outputs it to the recirculation pump 14.

[0031] The input circuit breaker panel 9, which includes the input circuit breaker 3, and the bank electrical panel 10, which includes the first bank 7 and the second bank 8, are non-SA equipment. The output circuit breaker panel 11, which includes the output circuit breaker 4, is SA equipment. In other words, the area upstream of the first bank 7 and the second bank 8 is configured as normal equipment. The area downstream of the two output circuit breakers 4 is configured as earthquake-resistant equipment capable of handling serious accidents.

[0032] In other words, the bank electrical panel 10, which serves as the first electrical panel and houses the first bank 7 and the second bank 8, and the output circuit breaker panel 11, which serves as the second electrical panel and houses two output circuit breakers 4, which serve as the first and second output circuit breakers, are separated in terms of seismic resistance. Furthermore, the output circuit breaker panel 11 is configured to have greater seismic resistance than the bank electrical panel 10.

[0033] The first bank 7 and second bank 8 of the reactor power supply unit 101 are semiconductor conversion circuits. These first bank 7 and second bank 8 are arranged in parallel with each other. The first bank 7 and second bank 8 each include a semiconductor forward conversion circuit 5 and a semiconductor inverse conversion circuit 6.

[0034] The semiconductor forward converter circuit 5 converts the three-phase alternating current input from the high-voltage busbar 1 within the plant via the input transformer 2 and input circuit breaker 3 into direct current. The semiconductor reverse converter circuit 6 converts the direct current obtained by the semiconductor forward converter circuit 5 into alternating current of any desired frequency.

[0035] The reactor power supply unit 101 increases or decreases the reactor output by controlling the voltage and frequency of the AC power supplied to the electric motor 13. For example, the reactor power supply unit 101 controls the flow rate of the coolant in the recirculation pump 14 and the rotational speed of the electric motor 13 to control the reactor output.

[0036] During the operation of the nuclear power plant, the reactor condition monitoring device 15 continuously monitors the reactor. The reactor condition monitoring device 15 is a computer that has hardware resources such as a processor and memory, and the CPU (Central Processing Unit) executes various programs, thereby realizing software-based information processing using hardware resources. Furthermore, the control method for the reactor power supply unit 101 is realized by having the computer execute various programs.

[0037] In the event of a reactor malfunction, two events are specified as conditions for stopping the power supply to the electric motor 13. The first is the occurrence of an EOC event. The second is the occurrence of an ATWS event. An EOC event occurs when a turbine trip or generator load shedding occurs. An ATWS event occurs when, in the event of a reactor malfunction, the reactor pressure or reactor water level reaches a specified value under conditions in which a reactor scram does not occur.

[0038] When an abnormal event occurs in the reactor, the signals output from the reactor condition monitoring device 15 include the EOC-RPT signal 16 (Type 1 signal) and the ATWS-RPT signal 17 (Type 2 signal).

[0039] When an EOC (End-of-Cycle) event occurs, the reactor condition monitoring device 15 determines that an EOC event has occurred and transmits an EOC-RPT signal 16 to the bank electrical panel 10. The EOC-RPT signal 16 is a stop signal for the semiconductor forward converter 5 and semiconductor reverse converter 6 in the first bank 7 and second bank 8. As a result, the semiconductor switches in the semiconductor forward converter 5 and semiconductor reverse converter 6 are activated and the power supply is cut off.

[0040] The EOC-RPT signal 16 is a Type 1 signal that activates a function aimed at suppressing an increase in reactor power during turbine trip or generator load shedding, thereby maintaining the integrity of the fuel rods.

[0041] When an ATWS event occurs, if the reactor condition monitoring device 15 determines that an ATWS event has occurred and that the reactor water level has reached a specified value, the reactor condition monitoring device 15 transmits an ATWS-RPT signal 17 to the bank electrical panel 10. The ATWS-RPT signal 17 is a signal that opens the output circuit breaker 4 installed in the output circuit breaker panel 11.

[0042] The ATWS-RPT signal 17 is a Type 2 signal that activates a function to mitigate the rise in reactor pressure when the reactor pressure or reactor water level reaches a specified value in the event of a reactor abnormality where a reactor scram does not occur.

[0043] The ATWS-RPT signal 17 is separated from the EOC-RPT signal 16. In other words, the reactor power supply unit 101 is constructed as a circuit for the SA equipment, with separation and seismic resistance taken into consideration. The output circuit breaker panel 11 is installed as a second electrical panel with guaranteed seismic resistance to correspond to the SA equipment in the ATWS-RPT signal 17.

[0044] Figure 4 shows the connection between the bank electrical panel 10 and the output circuit breaker panel 11. The output circuit breaker panel 11 is equipped with two output circuit breakers 4 (Figure 3), but since these two output circuit breakers 4 have the same configuration, Figure 4 illustrates only the circuit of one output circuit breaker 4.

[0045] The output circuit breaker panel 11 is almost entirely SA (Safety Assurance) equipment, but a portion of it is non-SA equipment. For example, the circuit divisions are separated into SA equipment and non-SA equipment at the auxiliary relay 25. Each circuit division is electrically isolated. The auxiliary relay 25 electrically isolates the SA equipment circuits from the non-SA circuits.

[0046] The ATWS-RPT operating circuit 20 is powered by the DC power supply 18 for the SA. The ATWS-RPT operating circuit 20 includes an open-circuit protection relay 21 with respect to the ATWS-RPT operating contact 19. The open-circuit protection relay 21 is, for example, a trip coil.

[0047] When the reactor condition monitoring device 15 transmits the ATWS-RPT signal 17, the ATWS-RPT operating contact 19 of the ATWS-RPT operating circuit 20 closes, and the ATWS-RPT operating circuit 20 becomes operational. As a result, the open protection relay 21 operates, and the output circuit breaker 4 opens.

[0048] By switching between the first bank 7 and the second bank 8, the output circuit breakers 4 connected to the first bank 7 and the output circuit breakers 4 connected to the second bank 8 will open and close relative to each other. By sharing a part of the ATWS-RPT operating circuit 20 for this opening and closing operation associated with the bank switching, it becomes possible to limit the scope of modifications required to achieve the bank switching operation installed in existing equipment while still being able to execute the command for the bank switching signal 22.

[0049] Upon receiving a bank switching signal 22 from a predetermined control device (not shown), the bank switching operation contact 23 of the bank switching operation circuit 24 closes, activating the auxiliary relay 25. This auxiliary relay 25 activates the open protection relay 21 via the switching coupling circuit 26, which is a bank switching-ATWS communication circuit.

[0050] The operating circuit for the ATWS-RPT function is isolated from the EOC-RPT function. In particular, the operating circuit for the ATWS-RPT function is electrically isolated from the switching signals for the first bank 7 and the second bank 8 by an auxiliary relay 25. In other words, the operating circuit that opens the two output circuit breakers 4, which are the first and second output circuit breakers, when the ATWS-RPT signal 17, which is a second-class signal, is input, is electrically isolated from other circuits by the auxiliary relay 25.

[0051] The operating circuit for the ATWS-RPT function, which is required as an SA (Service Area) system, is separated from the operating circuit for the EOC-RPT function and is a standalone circuit. In particular, in the switching circuits for the first bank 7 and the second bank 8, the operating circuit for the ATWS-RPT function is electrically isolated by an auxiliary relay 25. In this way, the scope of SA system implementation is minimized, and the ATWS-RPT function is configured independently of the EOC-RPT function and the switching functions for the first and second banks, thereby ensuring that the ATWS-RPT function is provided as an SA system.

[0052] According to the first embodiment, the EOC-RPT signal 16, which is a first-class signal, is configured to be input to the first bank 7 and the second bank 8. When the EOC-RPT signal 16 is input to the first bank 7 and the second bank 8, semiconductor switches operate to interrupt the AC current. Furthermore, the ATWS-RPT signal 17, which is a second-class signal, is configured to be input to two output circuit breakers 4, which are the first and second output circuit breakers. When the ATWS-RPT signal 17 is input to the two output circuit breakers 4, they open to interrupt the AC current. In this way, the ATWS-RPT function can be realized in a circuit that satisfies the requirements for a severe accident response system.

[0053] (Second Embodiment) Next, the reactor power supply unit 102 of the second embodiment will be described with reference to Figure 5. Note that components identical to those shown in the previously described embodiment are denoted by the same reference numerals, and redundant descriptions are omitted.

[0054] The output circuit breaker panel 11 of the second embodiment does not have the switching connection circuit 26 (Figure 4) which is the bank switching-ATWS communication of the first embodiment. Instead, an auxiliary relay 28 for bank switching is provided. The auxiliary relay 28 for bank switching is, for example, a trip coil. The auxiliary relay 28 for bank switching is a trip coil provided separately from the open protection relay 21.

[0055] Upon receiving a bank switching signal 22 from a predetermined control device (not shown), the bank switching operation contact 23 of the bank switching operation circuit 24 closes, activating the auxiliary relay 25. This auxiliary relay 25 then activates the bank switching auxiliary relay 28.

[0056] The reactor power supply unit 102 of the second embodiment includes an open-circuit protection relay 21 and an auxiliary bank switching relay 28. The open-circuit protection relay 21 is a first electrical device that normally operates two output circuit breakers 4, which are the first and second output circuit breakers, individually. The auxiliary bank switching relay 28, unlike the first electrical device, is a second electrical device that operates the two output circuit breakers 4 simultaneously when an ATWS-RPT signal 17 (second-class signal) is input. In this way, the ATWS-RPT function can be realized in a circuit that satisfies the requirements for a severe accident response system.

[0057] (Third embodiment) Next, the reactor power supply unit 103 of the third embodiment will be described with reference to Figure 6. Note that components identical to those shown in the previously described embodiments are denoted by the same reference numerals, and redundant descriptions are omitted.

[0058] In the third embodiment, the reactor power supply unit 103 is configured such that the ATWS-RPT signal 17, which is a second-class signal, is input to two input circuit breakers 3, which are a first input circuit breaker and a second input circuit breaker. The two input circuit breakers 3 are opened to interrupt the AC when the ATWS-RPT signal 17 is input.

[0059] According to the third embodiment, the output circuit breaker 4 not only interrupts the AC on the downstream side of the first bank 7 and the second bank 8, but the input circuit breaker 3 can also interrupt the AC on the upstream side of the first bank 7 and the second bank 8.

[0060] Although the present invention has been described above based on the first to third embodiments, a configuration applied in any one embodiment may be applied to another embodiment, or the configurations applied in each embodiment may be combined.

[0061] According to at least one embodiment described above, the first and second output circuit breakers open and interrupt the AC when a Class II signal is input. This makes it possible to implement the ATWS-RPT function in a circuit that satisfies the requirements for a severe accident response system.

[0062] While several embodiments of the present invention have been described, these embodiments are presented as examples only and are not intended to limit the scope of the invention. These embodiments can be carried out in a variety of other forms, and various omissions, substitutions, modifications, and combinations are possible without departing from the spirit of the invention. These embodiments or their variations are included in the scope and spirit of the invention, as well as in the claims and their equivalents. Where there is a singular noun, it does not exclude plural nouns unless the context clearly indicates otherwise. Furthermore, conjunctions such as "and" and "or" are inclusive unless the context clearly indicates otherwise. [Explanation of symbols]

[0063] 1...High-voltage busbar, 2...Input transformer, 3...Input circuit breaker, 4...Output circuit breaker, 5...Semiconductor forward converter circuit, 6...Semiconductor reverse converter circuit, 7...Bank 1, 8...Bank 2, 9...Input circuit breaker panel, 10...Bank electrical panel, 11...Output circuit breaker panel, 12...Output transformer, 13...Electric motor, 14...Recirculation pump, 15...Reactor condition monitoring system, 16...EOC-RPT signal, 17...ATWS-RPT signal 18... DC power supply for SA, 19... ATWS-RPT operating contact, 20... ATWS-RPT operating circuit, 21... Open protection relay, 22... Bank switching signal, 23... Bank switching operating contact, 24... Bank switching operating circuit, 25... Auxiliary relay, 26... Switching coupling circuit, 27... Circuit breaker, 28... Auxiliary relay for bank switching, 100A, 100B, 101, 102, 103... Power supply unit for the reactor.

Claims

1. A first bank is provided between the external power supply and the recirculation pump, which converts the AC input from the external power supply into a preset voltage and frequency and outputs it to the recirculation pump. A second bank is provided in parallel with the first bank and serves as a backup for the first bank, converting the AC power input from the external power supply into a preset voltage and frequency, and outputting it to the recirculation pump. A first output circuit breaker is connected in series to the downstream side of the first bank and interrupts the AC when open, A second output circuit breaker is connected in series to the downstream side of the second bank and interrupts the AC when open, Equipped with, When an abnormal event occurs in a nuclear reactor, the signal output from the reactor condition monitoring device is A Class 1 signal that activates a function aimed at suppressing the rise in reactor output during turbine trip or generator load shedding to maintain the integrity of the fuel rods, A Type 2 signal that activates a function to mitigate the rise in reactor pressure when the reactor pressure or reactor water level reaches a specified value in the event that a reactor scram does not occur when the aforementioned abnormal event occurs in the aforementioned reactor, Includes, The first type signal is configured to be input to the first bank and the second bank, The system is configured such that the second type signal is input to the first output circuit breaker and the second output circuit breaker. When the first type signal is input to the first bank and the second bank, a semiconductor switch is activated to interrupt the AC. The first output circuit breaker and the second output circuit breaker are opened when the second type signal is input, thereby interrupting the AC. Power supply equipment for nuclear reactors.

2. The operating circuit that opens the first output circuit breaker and the second output circuit breaker when the second type signal is input is electrically isolated from other circuits by an auxiliary relay. The reactor power supply device according to claim 1.

3. The area upstream of the first bank and the second bank is configured as a normal facility. The equipment downstream of the first and second output circuit breakers is configured to handle serious accidents. A power supply device for a nuclear reactor according to claim 1 or claim 2.

4. The first electrical panel, which contains the first bank and the second bank, and the second electrical panel, which contains the first output circuit breaker and the second output circuit breaker, are separated. The second electrical panel has a configuration that provides greater earthquake resistance than the first electrical panel. A power supply device for a nuclear reactor according to claim 1 or claim 2.

5. A first electrical appliance that operates the first output circuit breaker and the second output circuit breaker individually under normal conditions, Unlike the first electrical appliance, the second electrical appliance operates the first output circuit breaker and the second output circuit breaker simultaneously when the second type signal is input, Equipped with, A power supply device for a nuclear reactor according to claim 1 or claim 2.

6. A first input circuit breaker is connected in series to the upstream side of the first bank and interrupts the AC when open, A second input circuit breaker is connected in series to the upstream side of the second bank and interrupts the AC when open, Equipped with, The system is configured such that the second type signal is input to the first input circuit breaker and the second input circuit breaker. The first input circuit breaker and the second input circuit breaker are opened when the second type signal is input, thereby interrupting the AC. A power supply device for a nuclear reactor according to claim 1 or claim 2.

7. The reactor is a boiling water reactor, and the AC power supplied to the electric motor that drives the recirculation pump that circulates the coolant of the reactor is controlled. A power supply device for a nuclear reactor according to claim 1 or claim 2.

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