KR20080051417A - Programmable logic controller based digital reactor protection system with independent double structure redundancy per channel and method thereof - Google Patents

Abstract

A programmable logic controller based digital reactor protection system with an independent double structure redundancy per a channel and a method thereof are provided to improve stability and reliability of a nuclear power plant so as to maintain the nuclear power plant in a safety state and to prevent radioactive rays and radioactive materials from being leaked to the outside. A programmable logic controller based digital reactor protection system with an independent double structure redundancy per a channel includes four channels(200) of a redundancy structure which operates independently. Each channel includes a first group and a second group. The first group includes a first bistable processor(201a) among double bistable processors and a first coincidence processor(202a) among double coincidence processors. The second group includes a second bistable processor(201b) among the dual bistable processors and a second coincidence processor(202b) among the dual coincidence processors. The first and second bistable processors generate trip signals by comparing input signals with a predetermined stored trip set value on the basis of a plurality of sensing signals indicating states of reactor systems. The first and second coincidence processors generate a final trip signal by performing 2/4 logic compounding of the trip signals outputted from the bistable processors of a corresponding group among the four channels. A reactor is stopped by driving a reactor trip breaker or engineered safety features are operated by driving an engineered safety features-component control system according to the final trip signal by independent operation of the first and second groups of the redundancy structure in each channel.

Description

Digital reactor protection system with independent redundancy structure redundancy and method thereof

1 is a view showing the configuration of a digital reactor protection system according to an embodiment of the present invention.

2 is a diagram illustrating a detailed configuration of each channel of the digital reactor protection system according to an embodiment of the present invention.

3 is a diagram for describing a simultaneous logic processor bypass circuit according to an exemplary embodiment of the present invention.

4 is a view for explaining the structure of the start circuit according to an embodiment of the present invention.

5 is a diagram illustrating an example of changing a set value using an engineering work system according to an embodiment of the present invention.

<Explanation of symbols for the main parts of the drawings>

200: channel

201a, 201b: comparative logic processors (BP1, BP2)

202a and 202b: simultaneous logic processors CP1 and CP2

203: Remote Stop Operator Module (RSR OM)

204: main control unit operator module (MCR OM)

205: cabinet operator module (COM)

206: start circuit

207: Automatic Test and Link Processor (ATIP)

The present invention is composed of four channels in order to stop the reactor in the digital reactor protection system using a digital controller (PLC) or to produce an operation signal for accident mitigation, the configuration and automatic logic of each channel is the maximum multiplicity In order to ensure the safety of each channel, the processor that doubles the safety function is doubled, and one group of processors satisfy the 1/2 simultaneous logic that shows the safety function of the channel, and the bypass logic for bypassing the faulty or serviced processor The change and modification of the set point is related to a digital reactor protection system and a method having an independent redundancy structure which is limited to only an external engineering workstation (EWS).

Nuclear power plants usually consist of more than 100 individual functions. They are largely nuclear-oriented nuclear steam supply systems (NSSS), secondary circulating cooling systems that deliver steam to generators, turbine generator systems that supply steam from secondary systems and run generators, and other accessories. It is divided into facilities. Looking at the pressurized light water reactor-type power plant, which is currently dominated by the Korean nuclear power plant, the primary system centered on the nuclear reactor, the secondary system including steam generators, turbines, generators and condensers, engineering safety equipment systems for accidents, transmission and distribution systems, It consists of measurement control system and other auxiliary systems.

In order to monitor the health of each system while operating the nuclear power plant as described above, various types of sensors are installed in the reactor system to monitor the signals input from the sensors to determine the state of the nuclear power plant. If any abnormality in the system affecting the safety of the nuclear reactor or cooling function in the nuclear steam supply system occurs during operation of the nuclear power plant, such an abnormal condition is detected and the reactor stop function is initiated by dropping the control rod. It is the reactor protection system that drives to cool the reactor. By performing these reactor protection functions, a nuclear power plant is kept safe even if an accident occurs, and radiation and radioactive materials are not leaked to the outside. Therefore, the reactor protection system plays the most important role in the safety and reliability of nuclear power plants. To be applied to the power plant site, the reactor protection system must be a system with high reliability and high precision. Even if a single fault inside or outside the protection system occurs, the ability to shut down the reactor should not be impaired.

To this end, nuclear power plants usually form a reactor protection system with four channels. Each of the four channels receives a plant status signal from a sensor or device belonging to that channel to determine reactor shutdown or safety equipment operating conditions, and when two or more channels are met, operating signals to shut down the reactor or operate the safety equipment. Occurs.

Up to now, even though analog reactor protection system or digital reactor protection system is used in Korea, the redundant structure for each channel has not been used. The Digital Plant Protection System (DPPS) used in Uljin 5 & 6 uses four simultaneous logic processors, which are also connected to each other using a backplane, resulting in independence.

The present invention has been made to solve the problems of the prior art as described above, by using a safety level PLC (POSAFE-Q) that accommodates four safety communication ports (POSAFE-Q) to form a fully independent redundancy structure in each channel reactor protection system It is an object of the present invention to provide a digital reactor protection system and a method for developing the logic of implementing the same.

In order to achieve the above object and to solve the above-mentioned problems of the prior art, the digital reactor protection system according to an embodiment of the present invention includes four channels of a redundancy structure operating independently, each channel is A first group comprising a first comparative logic processor among the dual comparative logic processors and a first concurrent logic processor among the dual concurrent logic processors; And a second group including a second comparative logic processor among the dual comparison logic processors and a second concurrent logic processor among the dual concurrent logic processors, and wherein the first and second comparative logic processors (BP) are bistable. The processor generates a trip signal by comparing an input signal value based on a plurality of detection signals representing the state of the reactor systems with a preset trip set value, and generates the first and second simultaneous logic processors (CP). Is a logical combination of trip signals output from the comparison logic processors of the corresponding group of four channels to generate a final trip signal, and independent of the first group and the second group of redundancy structures in the respective channels. Stop the reactor in response to the last trip signal, or stop the reactor shutdown breaker (RTSG) and engineering safety equipment. Characterized in that the drive system (ESF-CCS).

In addition, the method of redundancy of the digital reactor protection system according to an embodiment of the present invention, in the method of redundancy of the digital reactor protection system including four channels of redundancy structure operating independently, each channel of the dual comparative logic processor A first group comprising a first concurrent logic processor among a first comparative logic processor and a dual simultaneous logic processor; And a second group including a second comparative logic processor of the dual comparative logic processor and a second concurrent logic processor of the dual concurrent logic processor, wherein the second and second concurrent logic processors comprise: Generating a trip signal by comparing an input signal value with a pre-stored trip set value based on a plurality of detection signals indicating a state; And generating a final trip signal by performing a 2/4 logical combination of trip signals output from the comparison logic processors of the corresponding group of four channels in the first and the second simultaneous logic processors. Independent operation of the first group and the second group of redundancy structures either stops the reactor in accordance with the final trip signal, or stops the reactor shutdown circuit breaker (RTSG) and the engineering safety equipment-equipment control system (ESF-CCS). It is characterized by driving.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings and the contents described in the accompanying drawings, but the present invention is not limited or limited to the embodiments.

1 is a view showing the configuration of a digital reactor protection system according to an embodiment of the present invention.

As shown in FIG. 1, the digital reactor protection system 100 includes four channels 101, Channel A, B, C, and D, a redundancy operator module 102 (RSR OM), which has a redundancy structure. Main control room operator module (103, MCR OM) is included. The channel may be configured with N or more (N is a natural number of 3 or more), such as 3, 4, 5, 6, 7, and 8, but a redundancy structure of 4 channels is preferable in consideration of redundancy efficiency and circuit complexity. In addition, the four channels are configured to maintain physical and electrical independence between the channels. Remote stop room operator module (102, RSR OM) and main control room operator module (103, MCR OM) can monitor and control the operating state of the reactor protection system.

In addition, the digital reactor protection system 100 is composed of a cabinet that is equipped with a control device and a man-machine interface (MMI) related to test / diagnosis. External system has Tr. It consists of a CPC, a reactor trip unit (RTSG), and an engineering safety equipment-equipment control system (ESF-CCS). Here, Tr may be referred to as PI (Process Instrument).

The four channels (channel A, channel B, channel C, channel D) are driven completely independently from the sensor signal input terminal to the output terminal of each channel, and each of them through a communication method using a safety data link (SDL). A trip signal for each process variable of reactor systems output from a Bistable Processor (BP) of a channel is transmitted to a Coincidence Processor (CP) of another channel to exchange information between channels. The detection signal for each process variable measured by the sensor includes the pressure of each system, the factor value inside the reactor calculated by the Core Protection Calculator (CPC), and the Ex-core Neutron Flux Monitoring System (ENFMS). The neutron flux output values measured in) are included, and these values are input independently for each channel.

The sensor detection signals inputted to the input terminal are transmitted to the comparison logic processor BP to be compared with the trip setpoint stored in the comparison logic processor BP, and when the specific signal value exceeds the corresponding trip setpoint, the comparison logic processor (BP) generates a trip signal for that variable. The generated trip signal is transmitted through the safety data link to each simultaneous logic processor (CP of channel A, CP of channel B, CP of channel C, CP of channel D) in four channels. The simultaneous logic processor (CP) performs a 2/4 logic combination on the trip signal for each process variable output from the comparative logic processor (BP) in four channels to satisfy the logic, that is, from two of four channels. If the logic values are the same, the final trip signal is generated and sent to the initiating circuit. Upon receiving the final trip signal, the initiating circuit shuts down the control rod power through a reactor trip switch gear (RTSG) to drive the reactor stop by dropping the control rod, and the engineering safety equipment-system control system (ESF). -CCS: Engineered Safety Features-Component Control System (CCS) to cool the reactor.

Hereinafter, a detailed configuration of each channel will be described with reference to FIG. 2.

Each channel 200 of the digital reactor protection system 100 includes a first and second comparative logic processors 201a and 201b in a redundant structure, a first and a second simultaneous logic processors 202a and 202b in a redundant structure, and remote stop. Real Operator Module 203 (RSR OM), Main Control Operator Module 204 (MCR OM), Cabinet Operator Module 205, COM, Initiation Circuit 206, Automated Test and Link Processor 207, ATIP, and Other Hardware Devices Each processor and an operator module (OM) are connected through a data communication network.

Comparative logic processors 201a and 201b, simultaneous logic processors 202a and 202b, automatic test and associated processor 207, and ATIP use a programmable logic controller (PLC). The digital controller (PLC) comprises an input / output module for processing analog and digital signals, a CPU module for performing protection logic, a communication module for processing data communication, and a power module. Remote stop room operator module (203, RSR OM) and main control room operator module (204, MCR OM) can monitor and control the operating state of the reactor protection system.

The digital reactor protection system 200 satisfies the safety class (Class 1E) and is classified into seismic category I. In the case of software, the software installed in the cabinet operator module 205 and the COM and the automatic test and associated processor 207 and ATIP are safety related, comparative logic processors 201a and 201b and simultaneous logic processors. The ones at 202a and 202b are Safety Critical.

The first comparative logic processors 201a and BP1 and the first simultaneous logic processors 202a and CP1 are the first group, and the second comparative logic processors 201b and BP2 and the second concurrent logic processors 202b and CP2 are the first group. It is composed of a redundant structure as two groups. The first group and the second group in the channel are completely separated from the input module to the output module, and share sensor sensing signals for each process variable or predetermined input signals for each trip variable. That is, only the processors belonging to each group are interconnected, and the comparative logic processors and the concurrent logic processors in different groups operate independently. The output of the comparative logic processor (e.g., BP1 output) is the same group and the same group simultaneous logic processor (CP1 of channel A, CP1 of channel B, CP1 of channel C, channel C) of the same channel and other channels through the safety data link (SDL). CP1 of D).

The comparison logic processors 201a and 201b acquire an input signal value based on sensor detection signals converted into a digital signal through an input signal processing processor, and compare the value with a trip set value to determine a trip or pre-bit state. .

Comparative logic processors 201a and 201b determine a trip setpoint, which includes a fixed setpoint, a manual reset type variable setpoint, and a ratio limiting variable setpoint.

In addition, the comparative logic processors 201a and 201b each channel trip (prebit trip) when the input process value exceeds the trip (previous trip) setting value (decreases) or decreases below the trip (prebeat trip) setting value (falling type). Occurs. For the corresponding sensed signal, which is a digital input trip variable from the core protection calculator CPC, the channel trip (prebit trip) is determined according to the determined trip (prebeat trip) signal.

The comparative logic processors 201a and 201b receive a bypass request signal for each channel from a driver through a switch at the front of each channel 200 when the process value is within an allowable range, and initiate a driving bypass. When the operation bypass is entered, the comparative logic trip and the pre-trip for the corresponding trip variables (log output trip and pressurized base pressure trip) are bypassed and invalidated. When the process value is out of the allowable range, the started operation bypass is automatically removed.

In addition, the comparative logic processors 201a and 201b are dual simultaneous logic processors of the four channels (magnetic channel and other channels) through the safety data link (SDL) to trip, pre-bit, bypass request, bypass and beat signal. Transmits a status signal. In addition, the comparison logic processors 201a and 201b transmit the state information and the operation information to the remote stop operator module 203 (RSR OM) and main control room operator module 204 through an inter-channel network (ICN). , MCR OM), cabinet operator module (205, COM), and automatic test and associated processor (207, ATIP).

Simultaneous logic processors 202a and 202b generate a final trip signal by logically combining two-by-variable trip signals output from the comparison logic processors of the four channels. Simultaneous logic processors 202a and 202b send the generated final trip signal to the initiating circuit 206, IC. Simultaneous logic processors 202a and 202b transmit operation information such as trip state and trip channel bypass state to the remote stop room operator module 203 (RSR OM) and main control room operator module 204 through the channel internal communication network (ICN). OM), cabinet operator modules (205, COM), and automatic test and associated processors (207, ATIP).

According to the present invention, it is necessary to bypass the failure or the output of the channel under test for the maintenance and testing of the comparative logic processor. To this end, the concurrent logic processors 202a and 202b provide a means for bypassing individual trip variables and all channel bypass trap channels. The individual trip variable bypass bypasses only one channel for one trip variable, and a variable to which a trip channel bypass (TCB) has already been applied may ignore a trip channel request of another channel. At this time, trip channel bypass is allowed for other variables in one channel. If a trip channel request for the same variable is input in two or more channels at the same time, the priority is given in the order of A, B, C, and D channels.

The all-channel bypass (ACB) may bypass one channel as a whole, and bypassing two or more channels at the same time is prohibited. The full channel bypass is initiated when a bypass is required for a channel to be bypassed in three or more channels. That is, in order to initiate full channel bypass of channel A, all channel bypass for channel A must be input in three or more channels among four channels A, B, C, and D.

number A button status B button status C button status D button status error decision One 0 0 0 0 0 N 2 0 0 0 One 0 D 3 0 0 One 0 0 C 4 0 0 One One One N 5 0 One 0 0 0 B 6 0 One 0 One One N 7 0 One One 0 One N 8 0 One One One One N 9 One 0 0 0 0 A 10 One 0 0 One One N 11 One 0 One 0 One N 12 One 0 One One One N 13 One One 0 0 One N 14 One One 0 One One N 15 One One One 0 One N 16 One One One One One N

Table 1 shows a signal verification logic table for all channel bypass request inputs. Herein, the alphabet displayed in the decision field is N (Normal) is not a bypass request, A is a channel bypass request, B is a B channel bypass request, C is a C channel bypass request, D is a D channel bypass request Indicates.

The channel 200 receives a bypass request signal for the first and second comparative logic processors belonging to each channel through a switch on the front panel of each channel, and transmits the request signal to the simultaneous logic processors of the four channels. According to the signal verification algorithm, the simultaneous logic processors 202a and 202b are valid only when only one of the four switches of each channel is pressed (number: 2, 3, 5, 9) or both are released (number: 1). And all other conditions are treated as errors. For example, the simultaneous logic processors 202a and 202b generate an ERROR signal when three of the four channels are different or only two types are different. In case of an error, an alarm is displayed and a decision is made that no bypass is required. The signal verification algorithm can be equally applied to the number of 16 cases as described above even when only one button is pressed and another button is used to return a button that is already pressed.

A channel request status B channel request status C channel request status D channel request status error decision N N N N 0 N A N A A 0 A N A B C One N N N N C 0 N A N N D 0 N N N A N 0 N N N A A 0 N B B B B 0 B N N A C 0 N N N A D 0 N N N B N 0 N N N B A 0 N B C B B 0 B B N B C One N N N B D 0 N A D C C One N N N C A 0 N N N C B 0 N N C C C 0 C N N C D 0 N D B D D 0 D N N D A 0 N A A D B One N N N D C 0 N N N D D 0 N ... ... ... ... ... ...

Table 2 shows an example of all channel bypass confirmation logic (3/4) and an error occurrence logic. Herein, the alphabet displayed in the decision field is N (Normal) is not a bypass request, A is a channel bypass request, B is a B channel bypass request, C is a C channel bypass request, D is a D channel bypass request Indicates.

Simultaneous logic processors 202a and 202b are bypassed in all channels when requesting a bypass for a channel to be bypassed in three or more of the four channels. As shown in Table 2, the decision field "A" row requires the bypass of channel A in all channels A, C, and D except channel B. In this case, at least three of the four channels are assigned to channel A. The bypass request for channel A is valid. Similarly, in the decision field “D” row, only channel B requires channel B to bypass channel D and all other channels A, C, and D require channel D to be bypassed. The bypass request for channel D is valid because all channel bypass is entered for.

In addition, the simultaneous logic processors 202a and 202b perform two-fourth simultaneous logic of the comparative logic trip signal for each trip variable input in the four channels. If a trip channel bypass exists for a variable due to a failure of the process variable input unit, the bypass channel is ignored for that variable and a trip occurs if 2/3 simultaneous logic is satisfied among the remaining three channel signals.

The all-channel bypass bypasses only the comparative logic processor, and there is no method of blocking the output signal in the unavailable state of the output module of the concurrent logic processor, such as a failure or testing of the concurrent logic processor. The output of each channel produces the final reactor stop or safety device operation signal of the channel by 1/2 logic, so even when maintenance or failure of the simultaneous logic processor, the above operation signal is stopped / operated by the fail safe design. The signal is generated on that channel. Another optional package (B-type) in accordance with the present invention can bypass (overpass) a simultaneous logic processor that is failing or under maintenance in a redundant channel. At this time, it is configured as an interworking structure so as not to bypass the two simultaneous logic processors in only one channel.

Hereinafter, the simultaneous logic processor bypass method will be described with reference to FIG. 3.

Each channel 200 includes a bypass switch 301 of the first simultaneous logic processor 202a and a bypass switch 302 of the second concurrent logic processor 202b. Each channel 200 is selectively selected by a driver to bypass the switch 301 of the first simultaneous logic processor 202a or the bypass switch 302 of the second concurrent logic processor 202b. In this case, the operator may select only one bypass switch at a time so that both the first simultaneous logic processor 202a and the second simultaneous logic processor 202b cannot bypass. When one bypass switch is selected by the operator, an output contact of an output module for any one concurrent logic processor may be turned on or off to bypass the corresponding concurrent logic processor.

As shown, when the operator presses the bypass switch 301, the connection of the bypass relay a of the first simultaneous logic processor 202a is turned on and the bypass relay b of the second simultaneous logic processor 202b is connected. This is off and only the second simultaneous logic processor 202b is bypassed. Therefore, there is no case that two simultaneous logic processors bypass at the same time.

Hereinafter, the structure of the start circuit will be described with reference to FIG. 4.

The initiation circuit 206 (IC: Initiation Circuit) includes two watchdog timers 401, WDT1, and WST2, an optical transmitter 402, and ESFS, a relay coil 403, a variable capacitor, a diode, and a power supply. It is composed. More specifically, the initiating circuit 206 is configured to start at the time of CPU failure of the simultaneous logic processors 202a and 202b using a watchdog timer in series, and configured in series and in parallel. It is characterized by.

The initiating circuit 206 receives output signals from the simultaneous logic processors 202a and 202b of each group to shut down the reactor via a reactor stop circuit breaker (RTSG) or through an engineering safety equipment-equipment control system (ESF-CCS). Operate safety equipment. The initiating circuit 206 implements the output of the two groups of simultaneous logic processors 202a, 202b in half logic or logic that selects two outputs. The output of the reactor protection system initiation circuit is connected via the hardwire to the reactor stop circuit breaker (RTSG) of the corresponding channel, and the output of the engineering safety equipment-device control system (ESF-CCS) initiation circuit is connected to the engineering safety equipment-equipment through the optical cable. Control System Connects to the group controller of each division.

The watchdog timer 401 monitors the pulsation signals of the simultaneous logic processors 202a and 202b, and if an error occurs in the pulsation signal, the watchdog timer opens the initiation circuit to enable the reactor stop circuit breaker (RTSG) and engineering safety equipment. Generate a start signal for the ESP-CCS.

The initiation circuit 206 may generate an initiation signal for reactor shutdown, engineering safety equipment operation, and prohibition of control rod withdrawal depending on the conditions of the input variables. This start signal is realized by the de-energized relay coil 403 being operated. Types of the start signal include an under voltage reactor stop, a shunt reactor stop, a safety injection start, a main steam sequestration start, a containment containment start, a containment tank start, a first auxiliary water supply start and a second auxiliary water supply start. Start, control rod withdrawal operation.

The automatic test and interface processor (207, ATIP) tests whether the functions of the comparative logic processors 201a and 201b and the simultaneous logic processors 202a and 202b in the channel and other channels are operating correctly. Watch. The automatic test and link processor (207, ATIP) is configured from the comparative logic processor (201a, 201b) to the state of the variable value, set value, trip / pre-trip state, operation bypass, etc. to the intra-channel data network (ICDN) It receives the input through the monitoring logic processor 201a, 201b. In addition, the automatic test and associated processor 207 (ATIP) receives the status of trip, trip channel bypass, and all channel bypass from the simultaneous logic processors 202a and 202b through the channel internal communication network (ICDN). , 202b).

The automatic test and link processor (207, ATIP) is an engineering safety equipment-device control system (ETIP, ESF-CCS Test & Interface Processor) and the safety data link (SDL). It receives the state information of the ESF-CCS, and transmits it to the operator module (OM). In addition, it detects and monitors the connection status (current flow) of each leg of the reactor stop circuit breaker (RTSG) and monitors the internal devices such as the cabinet internal power supply, temperature detector, cabinet door open signal, and start circuit. Obtain and monitor operating status.

In addition, the automatic test and associated processor (207, ATIP) provides the Trouble state of the digital reactor protection system 100 to the cabinet operator module (205, COM) and the information processing system (IPS). Trouble alarms of the digital reactor protection system 100 include cabinet temperature anomalies, hardware failures and test errors. The automatic test and associated processor (207, ATIP) shall provide the CPC Test Enable output signal to the CPC if both Low DNBR and High LPD are bypassed within the channel. The automatic test and associated processor 207 (ATIP) determines the bypass status when the concurrent logic processors 202a and 202b in the cabinet are both trip channel bypasses for the above two variables.

The automatic test and associated processor 207 (ATIP) shall have a manual start automatic test function to confirm that the comparative logic processor and the simultaneous logic processor perform correctly. The automatic test function can be performed manually or automatically by the operator if necessary. To this end, the automatic test and associated processor 207 (ATIP) generates a test start signal for the automatic test and transmits it to the comparison logic processor and the simultaneous logic processor, the feedback can be confirmed the soundness.

The automatic test and associated processor 207 (ATIP) generates a pulsating signal to ensure soundness and transmits the signal to the watchdog timer 301 of the initiating circuit 206 through the digital output module. In addition, the automatic test and associated processor 207 (ATIP) transmits a heartbeat signal through the channel data communication network (ICDN) to monitor the operation state of the automatic test and the associated processor in the channel or other channels.

Operator linkage of the digital reactor protection system 100 is composed of a remote stop room operator module (203, RSR OM), main control room operator module 204 (MCR OM) and the cabinet operator module (205, COM). Here, the remote stop room operator module 203 (RSR OM) and the main control room operator module 204 (MCR OM) operate a reactor operation such as driving bypass and manual reset. The cabinet operator module 205 (COM: Cabinet Operator Module) performs various monitoring and manipulations for preventive maintenance and repair. These signals are initiated through a hardware switch and transmitted via hardwires to the associated comparative or concurrent logic processor.

In the cabinet operator module 205, COM, Trip-Channel Bypass (TCB), All-Channel Bypass (ACB), and Reactor Protection System Reset Circuit Breaker Reset ), And reset the safety signal of the engineering safety equipment (ESF) through the hardware switch. The cabinet operator module 205 (COM) is composed of a touch screen, a computer, a trackball, a keyboard, and a manual control panel, and is installed at the front of the cabinet, one for each channel. The cabinet driver module 205 (COM) is connected to the comparative logic processors 201a and 201b, the simultaneous logic processors 202a and 202b, the automatic test and associated processor 207 and ATIP through the channel internal communication network (ICN), and the reactor. It is used as a gateway for transmitting the operating state of the protection system to an information processing system (IPS).

The digital reactor protection system 100 has three types of data communication networks for signal transmission between each processor module. The safety data link (SDL) transmits the output of the comparative logic processors 201a and 201b to the simultaneous logic processors 202a and 202b, and uses unidirectional and deterministic protocols. The communication between the automatic test and associated processor (207, ATIP) and the engineering safety equipment-device control system (ESF-CCS) test and associated processor (ETIP) is also made up of SDL. The channel internal communication network (ICN) is used to exchange information between the comparative logic processors 201a and 201b, the simultaneous logic processors 202a and 202b, the automatic test and link processor 207 (ATIP), and the operator module (OM) in each channel. Used. Inter-channel data communication network (ICDN) is a communication network that connects channels to each other, and exchanges operation information between each channel's automatic test and associated processor (207, ATIP), and the QIAS (Qualified Indication & Alarm System) Perform communication between the test and associated processors (207, ATIP).

Hereinafter, a method of changing a set value using an engineering work system (EWS) will be described with reference to FIG. 5.

The digital reactor protection system 100 further includes an engineering workstation 501 (EWS: Engineering Work Station), a reactor protection system stop breaker reset (502, RPS: Trip Circuit Breaker Reset).

The engineering workstations 501 and EWS are used to enter the setpoints and associated constants for each processor or hardware in the reactor protection system. The operator may change the stop setpoints associated with the reactor stop managed in the reactor protection system stop circuit breaker reset (RPS) after user authentication via an engineering workstation (EWS). This is to prevent easy change of the stop setpoint for the safety of the digital reactor protection system (100). The engineering workstation for changing the setpoint (501, EWS) is separated from the digital reactor protection system 100 after the change of the setpoint is stored by the management procedure of the nuclear power plant and used for other general purposes except printing or checking the record. This can be controlled.

The redundancy method of the digital reactor protection system according to the present invention can be implemented in the form of program instructions that can be executed by various computer means and recorded in a computer readable medium. The computer readable medium may include program instructions, data files, data structures, etc. alone or in combination. Program instructions recorded on the media may be those specially designed and constructed for the purposes of the present invention, or they may be of the kind well-known and available to those having skill in the computer software arts. Examples of computer-readable recording media include magnetic media such as hard disks, floppy disks, and magnetic tape, optical media such as CD-ROMs, DVDs, and magnetic disks, such as floppy disks. Magneto-optical media, and hardware devices specifically configured to store and execute program instructions, such as ROM, RAM, flash memory, and the like. Examples of program instructions include not only machine code generated by a compiler, but also high-level language code that can be executed by a computer using an interpreter or the like. The hardware device described above may be configured to operate as one or more software modules to perform the operations of the present invention, and vice versa.

As described above, although the present invention has been described with reference to limited embodiments and drawings, the present invention is not limited to the above embodiments, and those skilled in the art to which the present invention pertains various modifications and variations from such descriptions. This is possible.

Therefore, the scope of the present invention should not be limited to the described embodiments, but should be determined not only by the claims below but also by the equivalents of the claims.

As described above, the digital reactor protection system and method thereof according to the present invention employ a redundant redundancy structure in which two groups including a comparative logic processor and a simultaneous logic processor operate completely independently on each channel of the digital reactor protection system. Thus, even if an accident occurs in the nuclear power plant, the nuclear power plant can be maintained in a safe state and contribute to improving the safety and reliability of the nuclear power plant so that radiation and radioactive materials do not leak to the outside.

Claims (9)

In the digital reactor protection system, Including four channels of redundancy structure operating independently, Each channel A first group comprising a first comparative logic processor among the dual comparative logic processors and a first concurrent logic processor among the dual concurrent logic processors; And A second group including a second comparative logic processor of the dual comparative logic processors and a second concurrent logic processor of the dual concurrent logic processors, The first and second Bistable Processors (BP) A trip signal is generated by comparing an input signal value with a pre-stored trip set value based on a plurality of detection signals indicating a state of reactor systems. The first and second concurrent logic processors (CP), Generating a final trip signal by logically combining trip signals output from the comparison logic processors of the corresponding group of 4 channels by 2/4, Independent operation of the first group and the second group of redundancy structures in each channel drives the reactor stop circuit breaker (RTSG) according to the final trip signal to stop the reactor or the engineering safety equipment-equipment control system. Digital reactor protection system, characterized by operating the engineering safety equipment (ESF) by driving the (ESF-CCS). The method of claim 1, A starter circuit having a watchdog timer in series to be started at the time of CPU failure of the first and second simultaneous logic processors and configured in series and in parallel Digital reactor protection system further comprises. The method of claim 1, Automatic Test and Interface Processor (ATIP), which collects the operating status of dual comparative logic processors and dual simultaneous logic processors in channels and other channels to diagnose their health. Digital reactor protection system further comprises. The method of claim 1, Trip Circuit Breaker Reset (RPS) for managing stop setpoints for reactor shutdown; And Mobile Engineering Work Station (EWS) for changing the stop setpoint of the reactor protection system stop breaker reset (RPS) after user authentication Digital reactor protection system further comprises. The method of claim 1, Receives a bypass request signal for the first and second comparison logic processors belonging to each channel through a predetermined switch of each channel, and transmits the request signal to the simultaneous logic processors of the four channels, The dual simultaneous logic processor, Examining the bypass request signals of the four channels to determine the channel that matches the three values as the bypass channel, and bypasses the dual comparison logic processor determined as the bypass channel to perform 2/3 logic except the bypass channel. Digital reactor protection system, characterized in that. The method of claim 1, Each channel is A bypass switch of the first concurrent logic processor and a bypass switch of the second concurrent logic processor, When the bypass switch of the first simultaneous logic processor or the bypass switch of the second concurrent logic processor is selectively selected by an operator, by turning on or off the output contact of the output module for any one concurrent logic processor, the corresponding concurrent logic processor Digital reactor protection system, characterized in that for bypassing. In the digital reactor protection system, Includes N (N is a natural number of 3 or more) channels of independent redundancy structure, Each channel A first group comprising a first comparative logic processor among the dual comparative logic processors and a first concurrent logic processor among the dual concurrent logic processors; And A second group including a second comparative logic processor of the dual comparative logic processors and a second concurrent logic processor of the dual concurrent logic processors, The first and second Bistable Processors (BP) A trip signal is generated by comparing an input signal value with a pre-stored trip set value based on a plurality of detection signals indicating a state of reactor systems. The first and second concurrent logic processors (CP), Generating a final trip signal by performing a 2 / N logical combination of trip signals output from the comparison logic processors of the corresponding group of 4 channels, And monitoring the reactor systems according to the final trip signal by independent operation of the first group and the second group of redundancy structures in each channel. In the method of redundancy of the digital reactor protection system including four channels of independently operated redundancy structure, Each channel comprising: a first group comprising a first comparative logic processor of the dual comparative logic processors and a first concurrent logical processor of the dual concurrent logic processors; And a second group including a second comparative logic processor of the dual comparative logic processors and a second concurrent logic processor of the dual concurrent logic processors, Generating a trip signal by comparing a signal value input based on a plurality of detection signals representing states of nuclear reactor systems in the first and second comparison logic processors with a preset trip set value; And Generating a final trip signal by logically combining trip signals output from the comparison logic processors of the corresponding group of four channels in the first and second simultaneous logic processors; Including, Driving a reactor stop circuit breaker (RTSG) to stop the reactor in response to the final trip signal by independent operation of the first group and the second group of redundancy structures in each channel, or an engineering safety facility (ESF) A method of redundancy of a digital reactor protection system, characterized by driving an engineering safety equipment-equipment control system (ESF-CCS) for the operation of the system. A computer-readable recording medium having recorded thereon a program for executing the method of claim 8.

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