A safety level control system for a reprocessing plant

Abstract

The application discloses a kind of safety level control systems for post-processing plant, the system includes: process system access layer, process control layer and operation layer, process system access layer is used to transmit the safety level signal of process system to process control layer, safety level signal includes safety level instrument signal and safety level control device signal;Process control layer is between process system access layer and operation layer, process control layer includes safety level cabinet, safety level cabinet is used to collect and logic processing safety level signal, and the signal after collection and logic processing is transmitted to operation layer;Operation layer includes first safety level analog operating panel and second safety level analog operating panel, two safety level analog operating panels are connected with safety level cabinet, for monitoring safety level signal.The system can effectively reduce the risk of system failure caused by equipment failure, thereby reducing the overall failure probability of process system, improve system reliability and safety.

Description

Technical Field

[0001] This invention relates to the field of nuclear fuel reprocessing, and more specifically to a safety-level control system for a reprocessing plant. Background Technology

[0002] Currently, the control systems of my country's reprocessing plants employ a combination of digital and analog technologies. Digital technology is used in the non-safety-level control systems (DCS systems) that perform operations under normal conditions. At present, there are no mature digital products available for safety-level control systems in China's nuclear fuel reprocessing field; therefore, all safety-level control systems utilize analog technology.

[0003] The safety-level control system for after-treatment plants was developed after comprehensively considering the operational characteristics and economic factors of after-treatment plants, mainly based on the following reasons:

[0004] 1. Potential design-baseline accidents at the reprocessing plant include transport drop, component drop, nuclear criticality in equipment rooms, ignition of the co-decontamination organic phase, red oil explosion in the high-level radioactive waste evaporator, leakage from the high-level radioactive waste storage tank, and hydrogen explosion in the high-level radioactive waste storage tank. Although these accidents involve numerous physical and chemical reactions, their probability of occurrence is low, their progression is slow, and their impact is limited. Furthermore, multiple preventative measures have been incorporated into the design, and operators have ample time to bring the plant to a safe state after a design-baseline accident. Therefore, a dedicated safety system is not considered for the reprocessing plant. Equipment performing safety functions must participate in production operations under normal conditions and ensure plant safety under accident conditions.

[0005] 2. Under normal operating conditions, operators primarily rely on the DCS system to monitor safety-level equipment. Under design baseline accident conditions, operators can only monitor through the safety-level control system. Operators mainly operate from the central control room; if the central control room is unavailable, they should be transferred to the emergency control room.

[0006] 3. The process systems that perform safety functions in the post-processing plant are not designed with redundancy. Instead, they adopt the principle of having backup critical process equipment, with most having one in use and one on standby, and a small number of equipment having no backup.

[0007] 4. The scale of the safety-level control system in a reprocessing plant is similar to that of a nuclear power plant, but the operating characteristics of a reprocessing plant make the requirements for signal display, alarms, and manual operation far greater than those in a nuclear power plant.

[0008] Existing patent CN117590809A discloses a nuclear power plant instrumentation and control system, which includes a reactor protection system and a safety automation system. The reactor protection system is unidirectionally connected to the safety automation system; each control cabinet in the reactor protection system is bidirectionally connected to a first safety ring network, and each control cabinet in the safety automation system is bidirectionally connected to a second safety ring network; the safety level of the first safety ring network is higher than that of the second safety ring network. This scheme is mainly used to improve the reliability of the nuclear power plant's instrumentation and control system, but it does not conform to the operating characteristics of reprocessing plants and is difficult to meet the operational requirements of reprocessing plants.

[0009] Existing patent CN106340332A discloses a digital protection and control system for nuclear power plants. This system includes at least one sub-protection and control system, comprising three independent safety protection cabinets. Each safety protection cabinet performs threshold judgments on received field-acquired signals and sends the judgment results to the other safety protection cabinets. The receiving safety protection cabinet performs logical operations on its own judgment result and outputs the result as its action command. This solution focuses on reducing the high false alarm rate of the digital protection and control system and does not conform to the operational characteristics of reprocessing plants, making it difficult to meet the operational needs of reprocessing plants.

[0010] In conclusion, neither of the technical solutions corresponding to the two existing patents mentioned above are suitable for the operation characteristics of post-processing plants and cannot meet their operational needs. Summary of the Invention

[0011] Based on the above-mentioned technical problems, this invention proposes a safety-level control system for post-processing plants, which enables uninterrupted monitoring of safety-level parameters and equipment in post-processing plants under normal and design baseline accident conditions.

[0012] To achieve the above objectives, this invention proposes a safety-level control system for post-processing plants.

[0013] A safety-level control system for a reprocessing plant, comprising: a process system access layer, a process control layer, and an operation layer.

[0014] The process system access layer is used to transmit safety-level signals of the process system to the process control layer. Safety-level signals include safety-level instrument signals and safety-level control equipment signals.

[0015] The process control layer is located between the process system access layer and the operation layer. The process control layer includes a safety-level cabinet, which is used to acquire and process safety-level signals and transmit the acquired and processed signals to the operation layer.

[0016] The operation layer includes a first security level analog operation panel and a second security level analog operation panel. Both the first security level analog operation panel and the second security level analog operation panel are connected to the security level cabinet and are used to monitor security level signals.

[0017] Furthermore, the safety-grade cabinet includes a safety-grade signal acquisition cabinet and a safety-grade logic control cabinet. The process system access layer includes safety-grade instruments and safety-grade control equipment. The safety-grade signal acquisition cabinet is used to acquire and process safety-grade instrument signals; the safety-grade logic control cabinet is used to build the control loop of the safety-grade control equipment.

[0018] Furthermore, the safety-grade logic control cabinet also includes priority control logic loops, safety-grade control system and non-safety-grade control system switching loops, and alarm loops.

[0019] Furthermore, the safety-grade signal acquisition cabinet is equipped with an isolation power distribution module, which is used to supply power to the safety-grade instruments and split the safety-grade instrument signals into two independent first branch signals and second branch signals.

[0020] Furthermore, the safety-grade signal acquisition cabinet is also equipped with a signal isolation and transformation module and a signal conversion module. The first branch signal is divided into two independent signals by the first signal isolation and transformation module, which are transmitted to the non-safety-grade control system and the first safety-grade analog operation panel, respectively. The second branch signal is divided into two independent signals by the second signal isolation and transformation module, which are transmitted to the second safety-grade analog operation panel and the signal conversion module, respectively.

[0021] Furthermore, the safety-grade signal acquisition cabinet also includes relays. The signal conversion module is used to convert the received analog signals into digital signals, and transmit the digital signals to the safety-grade logic control cabinet via the first relay. The digital signals are then transmitted to the first safety-grade analog operation panel, the second safety-grade analog operation panel, and the non-safety-grade control system via the alarm circuit of the safety-grade logic control cabinet for alarm purposes. The signal conversion module is also connected to the safety-grade logic control cabinet via the second relay, and is used to transmit the digital signals to the safety-grade logic control cabinet via the second relay for safety-grade interlocking.

[0022] Furthermore, the safety-level control system is redundantly configured.

[0023] Furthermore, both the first and second safety-level analog operation panels are connected to the safety-level signal acquisition cabinet and the safety-level logic control cabinet, and are used to monitor the safety-level instruments and safety-level control equipment through the safety-level signal acquisition cabinet and the safety-level logic control cabinet.

[0024] Furthermore, the second safety-level analog control panel is used by the operator to continuously monitor safety-level signals when the first safety-level analog control panel is unavailable.

[0025] Furthermore, the operational layer also includes operator stations for monitoring the reprocessing plant under normal operating conditions via a non-safety-grade control system.

[0026] Based on the above technical solution, the present invention has at least the following beneficial effects:

[0027] 1. The safety-level control system proposed in this invention adopts simulation technology throughout. It is the first to realize a three-layer structure in a safety-level control system, namely the process system access layer, the process control layer and the operation layer. In addition, different redundancy schemes are set according to the process characteristics of the post-processing plant, which can effectively disperse the risk of system failure caused by equipment failure, thereby reducing the overall failure probability and improving system reliability.

[0028] 2. The process control layer of this invention mainly comprises a safety-grade signal acquisition cabinet and a safety-grade logic control cabinet, which are independent of each other and employ analog technology, achieving isolation between signal acquisition and logic control for the first time. The analog signal is divided into two completely independent signals by an isolation power distribution module in the safety-grade signal acquisition cabinet and then opto-isolated. Relay isolation is used to send the signals to the safety-grade analog control panel and the non-safety-grade control system respectively. Based on the above-mentioned opto-isolation, relay isolation, and other isolation methods, independent signal acquisition and control can be achieved, thereby reducing the risk of system failure and ensuring system reliability.

[0029] 3. This invention enables the switching between the safety-level control system and the non-safety-level control system by setting a switching loop inside the safety-level logic control cabinet, thereby meeting the operational needs of different working conditions. Under design baseline accidents, it shields instructions from the non-safety-level control system, ensuring the uniqueness and reliability of the safety-level control system instructions.

[0030] 4. This invention sets up two sets of safety-level simulation operation panels, allowing operators to monitor the safety-level parameters and equipment of the entire reprocessing plant from either set. When the central control room is unavailable, the system can be switched to the emergency control room, enabling operators to switch between the central control room and the emergency control room to implement a defense strategy.

[0031] 5. The safety-level control system proposed in this invention can utilize existing safety-level instruments and safety-level control equipment set according to process operation requirements, without the need to add additional dedicated instrumentation and control equipment, and can achieve uninterrupted monitoring of safety-level signals under both normal operating conditions and design baseline accident conditions. Attached Figure Description

[0032] The accompanying drawings, which form part of this specification, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0033] Figure 1 This is a schematic diagram of a safety-level control system for a post-processing plant according to an embodiment of the present invention;

[0034] Figure 2 This is a schematic diagram of signal transmission between the safety-level signal acquisition cabinet and the safety-level instruments, the first safety-level analog operation panel, the second safety-level analog operation panel, and the non-safety-level control system cabinet in one embodiment of the present invention.

[0035] Figure 3 This is a schematic diagram of the power supply circuit of the safety-level control system, which implements the switching control logic between the safety-level control system and the non-safety-level control system in one embodiment of the present invention.

[0036] Figure 4 This is a schematic diagram of the power supply circuit of a non-safety-level control system that implements the switching control logic between the safety-level control system and the non-safety-level control system in one embodiment of the present invention.

[0037] Figure 5 This is a schematic diagram of the control logic for switching between the first security level analog control panel and the second security level analog control panel in one embodiment of the present invention.

[0038] Figure 6 This is a schematic diagram of the control logic for switching between the first security level analog control panel and the second security level analog control panel in one embodiment of the present invention.

[0039] Figure 7 A schematic diagram of a safety-level control system for a post-processing plant according to another embodiment of the present invention.

[0040] The above figures include the following reference numerals:

[0041] 100. Operation Layer; 110. Central Control Room; 111. First Safety Level Simulation Operation Panel; 112. Operator Station; 120. Emergency Control Room; 121. Second Safety Level Simulation Operation Panel; 200. Process Control Layer; 210. Safety Level Cabinet; 211. Safety Level Signal Acquisition Cabinet; 2110. Isolation Power Distribution Module; 2111. First Signal Isolation and Transformation Module; 2112. Second Signal Isolation and Transformation Module; 2113. Signal Conversion Module; 2114. First Relay; 2115. Second Relay; 212. Safety Level Logic Control Cabinet; 220. Non-Safety Level Control System Cabinet Room; 221. Non-Safety Level Control System Cabinet; 300. Process System Access Layer; 301. Safety Level Instruments; 302. Safety Level Control Equipment. Detailed Implementation

[0042] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0043] The present invention will be further described in detail below with reference to specific embodiments, which should not be construed as limiting the scope of protection claimed by the present invention.

[0044] Example

[0045] To achieve uninterrupted monitoring of safety-critical parameters and equipment under normal and design-baseline accident conditions, this invention proposes a safety-level control system for reprocessing plants.

[0046] Considering the disadvantages of analog technology compared to digital technology in terms of signal interference resistance, computational accuracy, and fault tolerance, safety-level control systems based on analog technology should fully consider risk diversification and strategies to avoid malfunctions during design. For example... Figure 1 The diagram illustrates a safety-level control system for a post-processing plant according to an embodiment of the present invention. This safety-level control system comprises two independent, functionally identical safety-level sub-control systems, which achieve independent signal acquisition and control through various isolation methods. The system as a whole is divided into three layers: an operation layer 100, a process control layer 200, and a process system access layer 300, and all components utilize analog technology.

[0047] The operation layer 100 includes a first safety-level simulation operation panel 111, a second safety-level simulation operation panel 121, and an operator station 112. The two safety-level simulation operation panels serve as backups for each other and have the same detection parameters and controlled objects. Within the safety-level simulation operation panels, isolation measures such as cable laying path design, installation distance control, and cable conduits are used to send signals from the two sub-control systems to the two operation panels, ensuring both system independence and meeting operational requirements. Specifically, in this embodiment, the first safety-level simulation operation panel 111 is located in the central control room 110, and the second safety-level simulation operation panel 121 is located in the emergency control room 120. The two simulation operation panels are respectively connected to the safety-level cabinets 210 within the two safety-level sub-control systems, allowing operators to continuously monitor safety-level signals under both normal operating conditions and design-based accident conditions.

[0048] The second safety-level simulation control panel 121 is used by the operator to continuously monitor safety-level signals when the first safety-level simulation control panel 111 is unavailable. This allows the operator to switch between the operation of the first and second safety-level simulation control panels 111 and 121 from the central control room 110 and the emergency control room 120, thus implementing a defense withdrawal strategy. The operator station 112 is used to monitor the reprocessing plant under normal operating conditions through a non-safety-level control system.

[0049] The process control layer 200 is located between the process system access layer 300 and the operation layer 100. The process control layer 200 includes a safety-grade cabinet 210, which is used to implement control functions such as signal acquisition and distribution, threshold calculation and automatic interlocking logic, and control command output, and transmits the acquired and logically processed signals to the operation layer 100.

[0050] Specifically, the security-grade cabinet 210 includes a security-grade signal acquisition cabinet 211 and a security-grade logic control cabinet 212, which are connected to signals from different systems according to security design requirements. The first security-grade analog operation panel 111 and the second security-grade analog operation panel 121 are both connected to the security-grade signal acquisition cabinet 211 and the security-grade logic control cabinet 212, and are used to monitor security-grade signals through these two cabinets.

[0051] The process system access layer 300 transmits safety-level signals from the process system to the process control layer 200. These safety-level signals include safety-level instrument signals and safety-level control equipment signals. The process system access layer 300 transmits information one-to-one with the process control layer 200 via hard-wired safety-level cables, while simultaneously meeting safety design requirements through multiplexing, diversity, and isolated installation. Specifically, the process system access layer includes safety-level instruments and safety-level control equipment. The safety-level signal acquisition cabinet 211 is used to acquire and process safety-level instrument signals. The safety-level logic control cabinet 212 houses relays, SR triggers, and other electronic components, used to build control loops for all safety-level control equipment 302, priority control logic loops, switching loops between safety-level and non-safety-level control systems, and alarm loops. Specifically, control loops are built in the safety-level logic control cabinet 212 using relays, SR triggers, and other electronic components based on the switch signals from the safety-level signal acquisition cabinet 211 and the safety-level control equipment 302.

[0052] It should be understood that since analog signals are current signals, they will gradually attenuate in the control loop. Therefore, different signal allocation schemes are adopted in the safety-grade signal acquisition cabinet 211 according to the importance of the signal. For example, the electronic components in the signal loop should be minimized for safety-grade interlocking signals, safety-grade threshold alarm signals, and safety-grade control signals.

[0053] Furthermore, in this embodiment, the safety-grade signal acquisition cabinet 211 is equipped with an I / O terminal block, an isolation power distribution module 2110, a first signal isolation conversion module 2111, a second signal isolation conversion module 2112, a signal conversion module 2113, a first relay 2114, and a second relay 2115. The safety-grade signal acquisition cabinet 211 is used to acquire and process safety-grade signals, and output the signals one-to-one to the first safety-grade analog operation panel 111, the second safety-grade analog operation panel 121, and the non-safety-grade control system cabinet 221 through safety-grade cables in a hard-wired manner.

[0054] like Figure 2 As shown, the isolation power distribution module 2110 is used to supply power to the safety-grade instrument 301 and split the safety-grade instrument signal into two independent first branch signals and second branch signals, while performing opto-isolation. Then, the two signals are transmitted to the circuits of different subsequent systems respectively.

[0055] The first branch signal is split into two independent signals by the first signal isolation and transformation module 2111, and transmitted to the non-safety-level control system cabinet 221 and the first safety-level analog operation panel 111, respectively. The second branch signal can be directly transmitted to the second safety-level analog operation panel 121 by the second signal isolation and transformation module 2112; or, as in this embodiment, the second branch signal is split into two independent signals by the second signal isolation and transformation module 2112, and transmitted to the second safety-level analog operation panel 121 and the signal conversion module 2113, respectively.

[0056] After receiving the second branch signal output by the isolation power distribution module 2110, the signal conversion module 2113 converts the received analog signal into a switching signal for different purposes. The switching signal is then transmitted via the first relay 2114 to the safety-level logic control cabinet. From there, it is transmitted via the alarm circuit of the safety-level logic control cabinet to the first safety-level analog operation panel 111, the second safety-level analog operation panel 121, and the non-safety-level control system cabinet 220 for alarm purposes. For example... Figure 1 The signals ①③ collected and output by the safety-grade signal acquisition cabinet 211 and the signals ②④ processed and output by the safety-grade logic control cabinet 212 are transmitted to the non-safety-grade control system cabinet 221.

[0057] On the other hand, the signal conversion module 2113 in this embodiment is also connected to the safety-level logic control cabinet 212 through the second relay 2115, and is used to transmit the switching signal to the safety-level logic control cabinet 212 via the second relay 2115.

[0058] In the safety-grade signal acquisition cabinet of the process control layer, independent signal acquisition and control can be achieved through isolation methods such as isolation power distribution modules, relays, and signal isolation conversion modules, thereby reducing the risk of system failure and ensuring system reliability.

[0059] The reprocessing plant operates normally through a non-safety-level control system that monitors the entire plant. In the event of a design-baseline accident, operators can only monitor safety-related parameters and equipment through the safety-level control system. Therefore, a control logic for switching between the safety-level and non-safety-level control systems needs to be designed to shield commands from the non-safety-level control system during a design-baseline accident, ensuring the uniqueness and reliability of commands from the safety-level control system. Simultaneously, to comply with the reprocessing plant's defense-in-depth design principle, a switching control logic for the central control room and emergency control room also needs to be designed, enabling operators to continue monitoring from the emergency control room if the central control room becomes unavailable. To meet these requirements, the specific functions configured in the safety-level logic control cabinet at the process control layer include:

[0060] 1. Establish a safety-grade control loop. Utilize the switching signals from the safety-grade signal acquisition cabinet 211 and the safety-grade control device 302 to establish a control loop in the safety-grade logic control cabinet 212 using electronic components such as relays and SR triggers.

[0061] 2. Set up the switching control logic between the safety-level control system and the non-safety-level control system.

[0062] In one embodiment of the present invention, combined with Figure 3 , Figure 4 The power supply circuits for the safety-level control system and the non-safety-level control system, shown, implement the switching control logic between the safety-level and non-safety-level control systems. These circuits enable switching control between the safety-level and non-safety-level control systems. The operator controls the validity of signals under different operating conditions via a switch located on the safety-level analog control panel. Specifically... Figure 3In this diagram, A is a switch for switching between the safety-level control system and the non-safety-level control system, while B and C are relays. Relay B outputs three long-pulse signals, isolated by the relay, and transmits these signals to the first safety-level analog control panel 111 in the central control room, the second safety-level analog control panel 121 in the emergency control room, and the non-safety-level control system cabinet 220, respectively, to drive status indicator lights or indicator modules. Under normal operating conditions, switch A is in the "non-safe" position, and relay C is used to close the output long-pulse signal. Figure 4 The normally open contact G in the power supply circuit of the non-safety level control system activates the power supply circuit of the non-safety level control system. Figure 4 In the diagram, D and E are relays. Relays D and E receive on / off valve pulse signals from the non-safety-level control system and drive the safety-level control equipment. Under the design baseline accident condition, the switch is in the "safe" position, relay C is de-energized, and then the normally open contact G in the power supply circuit of the non-safety-level control system, which is in a closed state, is disconnected. The control signal of the non-safety-level control system fails, and all safety-level control equipment can only accept instructions from the safety-level cabinet. At the same time, the signal indicating the failure of instructions from the non-safety-level control system is fed back to the non-safety-level control system to ensure the consistency of equipment information.

[0063] 3. Switching control logic for the safety-level simulation operation panel in the central control room / emergency control room.

[0064] Figure 5 and Figure 6 This is a schematic diagram of the control logic for switching between a first-level safety simulation control panel and a second-level safety simulation control panel according to an embodiment of the present invention. The operator controls the validity of the operation signals from the two locations by using the switching switch R placed on the safety simulation control panel. Figure 5 In this diagram, M, P, N, and Q represent relays. Relays M and P output three long pulse signals after relay isolation, which are then transmitted to the first safety-level simulation control panel 111 in the central control room, the second safety-level simulation control panel 121 in the emergency control room, and the non-safety-level control system cabinet 220, respectively, to drive status indicator lights or indicator modules. When the operator is in the central control room, relay N outputs a long pulse to the signal safety-level cabinet, enabling... Figure 6 The normally open contact L of the intermediate safety-level cabinet closes, thereby activating the control circuit of the first safety-level analog control panel in the central control room. When the operator is in the emergency control room, relay Q outputs a long pulse signal to the safety-level cabinet, causing... Figure 6 The normally open contact O in the medium-safety cabinet closes, thereby activating the control circuit of the second-safety-level simulation operation panel in the emergency control room, while simultaneously cutting off the control command power supply to the central control room.

[0065] Furthermore, the safety level control system is redundantly configured, therefore the safety level cabinet 210 in the safety level control system is also redundantly configured.

[0066] Furthermore, based on the design principle of using backup rather than redundancy for safety-grade process equipment in post-processing plants, this invention proposes corresponding redundancy schemes for the process system access layer according to different situations:

[0067] 1. For active process equipment, the active safety-level process equipment in the post-processing plant is designed with one unit in operation and one unit on standby, and is located in two independent safety-level sub-control systems. Each piece of process equipment and its related safety-level instruments and safety-level control equipment belong to the same safety-level sub-control system, and the safety-level instruments on site are redundantly designed. The monitoring signals are transmitted to one of the safety-level sub-control systems for display, alarm and interlock control.

[0068] 2. For passive process equipment, generally speaking, regardless of whether the passive safety-level process equipment in the post-processing plant adopts a backup design, the relevant safety-level instruments of each process equipment are redundantly designed and are arranged in two independent safety-level sub-control systems. The monitoring signals are transmitted to the two safety-level sub-control systems for display, alarm and interlock control.

[0069] 3. In special cases, such as situations where redundancy settings for safety-level instruments are not possible due to process design (e.g.) Figure 7 The schematic diagram of a safety-level control system for a post-processing plant shown in another embodiment of the present invention requires that the safety-level signal be sent to the signal acquisition cabinet or logic control cabinet of one of the safety-level cabinets 210, and then the signal is sent to the first and second safety-level analog operation panels of the central control room and the emergency control room respectively after isolation and distribution, so as to achieve redundant configuration at the operation layer.

[0070] It should be understood that the setting strategy for safety-level instruments and the division strategy for safety-level control devices in the process system access layer of the above embodiments of the present invention can be formulated based on the actual setting of backup and safety-level measuring points for key process equipment in the post-processing plant.

[0071] In summary, as can be seen from the above description, the embodiments of the present invention achieve the following technical effects:

[0072] 1. The safety-level control system proposed in this invention adopts simulation technology throughout. It is the first to realize a three-layer structure in a safety-level control system, namely the process system access layer, the process control layer and the operation layer. In addition, different redundancy schemes are set according to the process characteristics of the post-processing plant, which can effectively disperse the risk of system failure caused by equipment failure, thereby reducing the overall failure probability and improving system reliability.

[0073] 2. The process control layer of this invention mainly comprises a safety-grade signal acquisition cabinet and a safety-grade logic control cabinet, which are independent of each other and employ analog technology, achieving isolation between signal acquisition and logic control for the first time. The analog signal is divided into two completely independent signals by an isolation power distribution module in the safety-grade signal acquisition cabinet and then opto-isolated. Relay isolation is used to send the signals to the safety-grade analog control panel and the non-safety-grade control system respectively. Based on the above-mentioned opto-isolation, relay isolation, and other isolation methods, independent signal acquisition and control can be achieved, thereby reducing the risk of system failure and ensuring system reliability.

[0074] 3. This invention enables the switching between the safety-level control system and the non-safety-level control system by setting a switching loop inside the safety-level logic control cabinet, thereby meeting the operational needs of different working conditions. Under design baseline accidents, it shields instructions from the non-safety-level control system, ensuring the uniqueness and reliability of the safety-level control system instructions.

[0075] 4. This invention sets up two sets of safety-level simulation operation panels, allowing operators to monitor the safety-level parameters and equipment of the entire reprocessing plant from either set. When the central control room is unavailable, the system can be switched to the emergency control room, enabling operators to switch between the central control room and the emergency control room to implement a defense strategy.

[0076] 5. The safety-level control system proposed in this invention can utilize existing safety-level instruments and safety-level control equipment set according to process operation requirements, without the need to add additional dedicated instrumentation and control equipment, and can achieve uninterrupted monitoring of safety-level signals under both normal operating conditions and design baseline accident conditions.

[0077] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

[0078] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes the element.

[0079] It should be noted that, in the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

Claims

1. A safety-level control system for a post-processing plant, characterized in that, include: The process system access layer, process control layer, and operation layer are all part of the system. The process system access layer is used to transmit the safety level signals of the process system to the process control layer. The safety level signals include safety level instrument signals and safety level control equipment signals. The process control layer is located between the process system access layer and the operation layer. The process control layer includes a safety-grade cabinet, which is used to acquire and process the safety-grade signals and transmit the acquired and processed signals to the operation layer. The safety-grade cabinet includes a safety-grade signal acquisition cabinet and a safety-grade logic control cabinet. The process system access layer includes safety-grade instruments and safety-grade control equipment. The safety-grade signal acquisition cabinet is used to acquire and process the signals from the safety-grade instruments. The safety-grade logic control cabinet is used to build the control loop of the safety-grade control equipment. The safety-level logic control cabinet also includes a priority control logic loop, a safety-level control system and a non-safety-level control system switching loop, and an alarm loop. The operation layer includes a first security level analog operation panel and a second security level analog operation panel. Both the first security level analog operation panel and the second security level analog operation panel are connected to the security level cabinet and are used to monitor the security level signals. The safety-grade signal acquisition cabinet is equipped with an isolation power distribution module, which supplies power to the safety-grade instruments and splits the instrument signals into two independent first branch signals and second branch signals. The cabinet also includes a signal isolation transformation module and a signal conversion module. The first branch signal is split into two independent signals by the first signal isolation transformation module and transmitted to the non-safety-grade control system and the first safety-grade analog control panel, respectively. The second branch signal is split into two independent signals by the second signal isolation transformation module and transmitted to the second safety-grade analog control panel and the signal conversion module, respectively. The safety-grade signal acquisition cabinet also includes a relay. The signal conversion module is used to convert the received analog signal into a switching signal, and transmit the switching signal to the safety-grade logic control cabinet via the first relay. The signal is then transmitted to the first safety-grade analog operation panel, the second safety-grade analog operation panel, and the non-safety-grade control system via the alarm circuit of the safety-grade logic control cabinet for alarm purposes. The signal conversion module is also connected to the safety-grade logic control cabinet via a second relay, and is used to transmit the switching signal to the safety-grade logic control cabinet via the second relay for safety-grade interlocking.

2. According to claim 1, the security-grade cabinet is further used to transmit the acquired and logically processed signals to the non-security-grade control system.

3. The system according to any one of claims 1 to 2, characterized in that, The safety level control system is redundantly configured.

4. The system according to claim 1, characterized in that, Both the first and second security-level analog operation panels are connected to the security-level signal acquisition cabinet and the security-level logic control cabinet, and are used to monitor the security-level signals through the security-level signal acquisition cabinet and the security-level logic control cabinet.

5. The system according to claim 1, characterized in that, The second safety-level simulation control panel is used by the operator to continuously monitor the safety-level instruments and the safety-level control equipment when the first safety-level simulation control panel is unavailable.

6. The system according to claim 2, characterized in that, The operation layer also includes an operator station for monitoring the reprocessing plant under normal operating conditions through the non-safety-level control system.

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