A method and system for safe operation of a nuclear reactor and a storage medium

Abstract

The present application relates to the technical field of nuclear reactor safe operation, and particularly relates to a nuclear reactor safe operation method and system and a storage medium, comprising the following steps: screening a region in which a system device for realizing reactivity control, residual heat removal and radioactivity containment function is located in a nuclear island system as an environmental monitoring point based on function analysis and safety evaluation principles of the nuclear island system; monitoring environmental parameters of the selected region; comparing the monitored environmental parameters with preset multi-level parameter thresholds; triggering corresponding reactor operation state intervention operations according to the comparison results; when the support system capacity is limited, preset resource allocation conditions are executed to preferentially guarantee the operation environment of a minimum device set required for realizing basic nuclear safety functions; the present application improves operation safety, optimizes resource allocation and ensures the preferential operation of a minimum safety system set under accident conditions by monitoring environmental parameters of key regions of compact small reactors in real time and executing hierarchical response operations based on multi-level parameter thresholds.

Description

Technical Field

[0001] This invention relates to the field of nuclear reactor safe operation technology, and in particular to a method, system and storage medium for safe operation of a nuclear reactor. Background Technology

[0002] Compact reactors (SMRs) have broad application prospects in scenarios such as factories, mines, ports, and islands far from the power grid due to their low thermal power, compact layout, and simplified system. However, SMRs have limited nuclear island space, low HVAC system redundancy, and small environmental parameter adjustment margins, making them susceptible to abnormally high environmental parameters during operation due to HVAC failures or accidents. High-temperature environments can cause thermal expansion of mechanical equipment, aging of rotating machinery lubrication, and deterioration of the insulation performance of electrical equipment and cables, which may lead to equipment malfunctions or failures to operate, threatening reactor safety.

[0003] Existing large nuclear power plants typically employ multiple redundant HVAC systems and cold supply subsystems, regulating plant cooling through site temperature measurement and cold source control. However, this approach involves numerous devices, requires significant space, and incurs high engineering costs, failing to meet the economic and compact requirements of small modular reactors (SMRs). Therefore, improvements to existing technologies are needed to adapt to safe operation methods specific to SMRs. Summary of the Invention

[0004] This invention provides a method, system, and storage medium for the safe operation of a nuclear reactor. By real-time monitoring of environmental parameters of key buildings in a compact small reactor and performing graded response operations based on multi-level parameter thresholds, it improves operational safety, optimizes resource allocation, and ensures the priority operation of the minimum set of safety systems under accident conditions.

[0005] This invention provides a method for the safe operation of a nuclear reactor, comprising: Based on the principles of functional analysis and safety evaluation of the nuclear island system, the areas where system equipment within the nuclear island system is located to achieve reactivity control, residual heat removal, and radioactive containment functions are selected as environmental monitoring points. Monitor environmental parameters of the selected area, including at least temperature parameters; The monitored environmental parameters are compared with preset multi-level parameter thresholds; Based on the comparison results, trigger corresponding reactor operation status intervention operations; When the system capacity is limited, preset resource allocation conditions are executed to prioritize the operating environment of the minimum set of equipment required to achieve basic nuclear safety functions.

[0006] In one embodiment of the present invention, the step of comparing the monitored environmental parameters with preset multi-level parameter thresholds and triggering corresponding reactor operation status intervention operations based on the comparison results includes: When environmental parameters reach the first-level threshold, the first intervention operation is triggered, including alarm and / or activation of backup system and / or initiation of maintenance to restore normal environmental parameters. If environmental parameters fail to recover to below the first-level threshold within a preset time after reaching the first-level threshold, a second intervention operation, including reducing reactor power or performing a reactor shutdown, is triggered. When environmental parameters reach a second-level threshold that is higher than the first-level threshold, a third intervention operation is triggered, including an emergency shutdown and initiation of the incident handling procedure.

[0007] In one embodiment of the present invention, in the step of triggering a third intervention operation, including emergency reactor shutdown and initiation of accident handling procedures, when environmental parameters reach a second threshold higher than the first threshold, When the third intervention operation is triggered, if the abnormal rate of increase of environmental parameters exceeds a predetermined rate threshold, or if the environmental parameters exceed a predetermined leakage threshold used as a leakage criterion, a diagnostic signal for potential abnormal fluid leakage is generated simultaneously and a leakage emergency procedure is triggered.

[0008] In one embodiment of the present invention, in the step of comparing the monitored environmental parameters with preset multi-level parameter thresholds, the method for setting the multi-level parameter thresholds includes: For each monitoring area, obtain the safe operating temperature limit for each device within that area; Based on the envelope principle, the lowest value among all equipment temperature limits is selected as the unified threshold benchmark for the region, and the unified threshold benchmark is checked and adjusted taking into account the requirements for human habitability.

[0009] In one embodiment of the present invention, in the step of executing preset resource allocation conditions to prioritize the operating environment of the minimum set of devices required to achieve basic nuclear safety functions when the support system capacity is limited, the preset resource allocation conditions include: In the event of a loss of external power, the emergency diesel generator system is activated, and available cooling and electrical resources are preferentially allocated to the HVAC subsystem that provides environmental protection for the minimum equipment assembly.

[0010] In one embodiment of the present invention, the step of preferentially allocating available cold and power resources to the HVAC subsystem that provides environmental protection for the minimum set of equipment includes: Control the central chilled water system to stop supplying cooling to non-safety-level users; Ensure that chilled water is supplied to the HVAC systems of the electrical instrumentation and control plant, the connection plant, and the diesel generator plant; Maintain at least some of the exhaust ventilation functions of the auxiliary plant.

[0011] In one embodiment of the present invention, in the step of executing preset resource allocation conditions to prioritize the operating environment of the minimum set of devices required to achieve basic nuclear safety functions when the support system capacity is limited, the preset resource allocation conditions further include: In the event of a plant-wide power outage, the plant-wide power-off diesel generator set is started, and the ventilation function that provides environmental protection for the minimum equipment set is gradually restored in a preset sequence.

[0012] In one embodiment of the present invention, the step of starting the plant-wide power-off diesel generator set during a plant-wide power outage and gradually restoring the ventilation function to provide environmental protection for the minimum equipment set in a preset order includes the following steps: First, restore ventilation in the diesel generator plant; Then, ventilation was restored in the electrical control and instrumentation workshop and the connecting workshop; Then restore the minimum ventilation function of the auxiliary plant; Based on this, at least the safety injection system and the waste heat removal system should be started.

[0013] The present invention also provides a safe operation system for a nuclear reactor, comprising: The parameter acquisition modules are distributed throughout the nuclear island in the areas where system equipment for implementing basic nuclear safety functions is located. The analysis and control module is communicatively connected to the parameter acquisition module, and the analysis and control module is configured as follows: The environmental parameters collected by the parameter acquisition module are compared with the pre-stored multi-level parameter thresholds; A control signal is generated based on the comparison results; The operation execution module is communicatively connected to the analysis and control module. The operation execution module is configured to perform corresponding operations in response to the control signal. The operations include multiple operations such as alarm operation, standby system start-up and shutdown operation, maintenance operation, reactor power reduction, reactor shutdown or emergency shutdown operation.

[0014] The present invention also provides a computer-readable storage medium having computer-readable instructions stored thereon, which, when executed by a computer's processor, cause the computer to perform the steps of any of the methods described herein.

[0015] The beneficial effects of this invention are as follows: This invention proposes a reactor safe operation method, system, and storage medium. Through nuclear island system functional analysis and safety evaluation, the area where the system equipment used to achieve reactivity control, residual heat removal, and radioactive containment functions is located within the nuclear island is selected as environmental monitoring points, ensuring that the monitoring targets cover the core area of ​​the reactor operation. The monitored environmental parameters are compared with preset multi-level parameter thresholds. Based on the comparison results, the reactor's operational safety risk level is determined, and corresponding graded response operations are executed: When at the first risk level, the first type of operation, including issuing an alarm and activating the backup system, is executed to remind the operator to intervene and repair in a timely manner; when at the first risk level and the environmental parameters do not recover within a preset time, or when at a higher second risk level, the second type of operation, including load reduction operation or reactor shutdown, is executed to prevent further deterioration of equipment performance; when at a higher third risk level, the third type of operation, including emergency reactor shutdown and entering the accident operation procedure, is executed to deal with extreme situations such as heat source leakage or system failure. When the support system capacity is limited under accident conditions, priority is given to ensuring the operation of a minimum set of safety systems, such as the reactivity control system, residual heat removal system, and radioactive containment system, to ensure that the reactor can be safely withdrawn to a shutdown state. This approach avoids the high-cost redundant design of large nuclear power plants through proactive monitoring and graded response, adapts to the compact characteristics of small modular reactors, effectively prevents equipment failures caused by abnormal environmental parameters, improves overall safety and operational efficiency, and optimizes the utilization of emergency resources. Attached Figure Description

[0016] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application. It is obvious that the drawings described below are merely some embodiments of this application, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0017] In the attached diagram: Figure 1 This is a schematic diagram of the main equipment layout of a compact small reactor according to an embodiment of the present invention; Figure 2 This is a simplified schematic diagram of a reactor chilled water process provided in one embodiment of the present invention; Figure 3 This is a flowchart of a method provided in one embodiment of the present invention; Figure 4 This is a detailed method flowchart provided in one embodiment of the present invention; The attached diagram is labeled as follows: pressurizer 1, reactor coolant pump 2, steam generator 3, reactor, auxiliary plant HVAC system 10, electrical and instrumentation plant HVAC system 20, containment ventilation and cooling system 30, connecting plant HVAC system 40, diesel generator plant HVAC system 50, central chilled water system 60, chilled water circulation pump 70, equipment cooling water system 80, equipment cooling water pump 90, and heat exchanger 100. The central chilled water system 60 provides chilled water to the HVAC systems of each plant via the chilled water circulation pump 70, and the equipment cooling water system 80 provides cooling to the central chilled water system 60 via the equipment cooling water pump 90 and heat exchanger 100. Detailed Implementation

[0018] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0019] It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. The drawings only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0020] In the following description, numerous details are explored to provide a more thorough explanation of embodiments of the invention. However, it will be apparent to those skilled in the art that embodiments of the invention may be practiced without these specific details. In other embodiments, well-known structures and devices are shown in block diagram form rather than in detail to avoid obscuring embodiments of the invention.

[0021] Emergency Diesel Generator (EDG) refers to a diesel generator system used to provide emergency power when external power is lost; Total Power Outage (SBO) refers to an accident condition in which a nuclear power plant completely loses its AC power supply; Total Power Outage Generator refers to a diesel generator set specifically designed for a total power outage condition; Central Chilled Water System 60 (VWS) refers to a centralized system that provides chilled water to the nuclear island's HVAC system; Equipment Cooling Water System 80 (CCS) refers to a system that provides cooling water to the nuclear island's equipment.

[0022] Small modular reactors (SMRs) typically refer to nuclear reactors with a thermal power output of less than 300 megawatts and a power generation output of less than 100 megawatts. These reactors are primarily located at construction or maintenance sites such as factories, mines, ports, and islands, far from the power grid but requiring electricity. They are characterized by high safety, cost-effectiveness, and practicality, and may even be mobile on water when necessary. Because they do not require ultra-high-voltage power grid transmission and distribution, their supporting infrastructure is relatively limited.

[0023] In terms of system configuration, the nuclear island system of small modular reactors (SMRs) adopts a streamlined design with a compact plant layout. It typically uses two loops, with two dedicated safety systems arranged in two rows, meeting the single-failure criterion for safety systems while effectively saving space. In practice, the pressurizer 1, reactor coolant pump 2, DC steam generator 3, and reactor pressure vessel 4 are centrally located on the nuclear island, significantly reducing the number of primary loops and piping, and minimizing the space required for the containment. Simultaneously, the chemical volume control system and safety injection system employ reduced-volume configurations, reducing the capacity of liquid storage tanks and the amount of waste liquid discharged. Specifically, for example… Figure 1 As shown.

[0024] In terms of safety system design, Steam Generator 3 does not have an emergency feedwater system. Instead, it adopts a combination of a secondary-side active waste heat removal system and a secondary-side passive waste heat removal system. A cooling source system is established by drawing water locally, employing a centralized chilled water system, eliminating the need for diverse chilled water designs. Furthermore, the small modular reactor (SMR) utilizes an advanced reactor control system, reducing the need for reactor coolant boric acid storage and purification systems, and enabling rapid start-up and shutdown operations.

[0025] The indoor environmental conditions of the nuclear island plant are ensured by heating, ventilation, and air conditioning systems. In addition to providing a safe and comfortable working environment for plant personnel, it is also essential to ensure the operability of the plant equipment. According to the performance requirements of electromechanical equipment, rotating machinery needs to operate under suitable temperature and humidity conditions; otherwise, performance degradation, accelerated equipment aging, and reduced reliability may occur, ultimately affecting the safe and stable operation of the nuclear island.

[0026] The HVAC system comprises several coordinated subsystems. The auxiliary plant HVAC system 10 is responsible for ventilation in the radioactive control area, ensuring the ventilation needs of the refueling water tank and auxiliary plant. During normal operation, this system maintains the ambient temperature of the auxiliary plant, hydrogen room, and battery room within the specified range, while providing necessary air supply to the pressure suppression tank. The system's safety function is to maintain the normal ambient temperature between the pump rooms of the safety injection system and the waste heat removal system under normal operation and emergency conditions. The system's ventilation and cooling functions are provided by the central chilled water system 60, which cools the pumps via coils. When the central chilled water system 60 is unavailable, the cooling function of the auxiliary plant HVAC system 10 will be lost. To ensure system reliability, the pump room fan coil units are powered by an emergency diesel generator, and the low-flow ventilation function is also powered by an emergency diesel generator. Figure 2 As shown.

[0027] The HVAC system 20 in the electrical and instrumentation control plant maintains suitable environmental conditions for personnel and equipment in the main control room, and provides a suitable operating environment for electrical and instrumentation equipment within the electrical plant. When the final heat sink is partially or completely lost, i.e., the equipment cooling water system 80 or the central chilled water system 60 becomes unavailable, the HVAC system 20 can still maintain basic ventilation functions, but will lose its cooling function. The control room HVAC system will be put into operation after the isolation valve of the habitable area in the main control room is closed. In the event of a loss of normal power supply, the HVAC system 20 can be powered by an emergency diesel generator.

[0028] The containment ventilation and cooling system 30 operates continuously during normal reactor operation to ensure the necessary environmental conditions for the equipment in the service area. In the event of an accident, if the chilled water supply is lost, the containment ventilation and cooling system 30 will lose its cooling function. After a loss of normal power supply, the system can be powered by emergency diesel generators and plant-wide power outage diesel generators. Upon receiving a containment isolation signal, the isolation valves on the containment ventilation and cooling system 30 pipelines will automatically close.

[0029] The HVAC system in the diesel generator plant is specifically designed to ensure a good operating environment for both emergency diesel generators and diesel generators operating during plant-wide power outages. The HVAC system for emergency diesel generators is powered by both emergency and non-emergency power supplies, while the HVAC system for diesel generators operating during plant-wide power outages can also be powered by the plant-wide power outage emergency power supply.

[0030] The HVAC system 40 in the connected plant is responsible for maintaining the temperature and humidity within the connected plant within the range required for equipment operation. Specifically, this includes maintaining the ambient temperature required for the normal operation of critical plant water pumps, equipment cooling water pumps 90, main central chilled water equipment, condensate suction pumps of the secondary waste heat removal system, main steam isolation valves, and other equipment. It also maintains the normal operating environment for instrumentation and control equipment at the remote shutdown station and the environment required for the normal operation of electrical equipment rooms. When the heat sink is partially or completely lost, i.e., the central chilled water system 60 or equipment cooling water system 80 becomes unavailable, the HVAC system 40 in the connected plant will lose its cooling function. In the event of a loss of normal power supply, the DC ventilation system of the HVAC system 40 in the connected plant will partially shut down, while the remaining parts can be connected to an emergency diesel generator to continue supplying power to ensure basic operation. In the event of a plant-wide power outage, the exhaust fans of the plant-wide power outage diesel generators and the exhaust fans of the remote shutdown station must be kept running, while the remaining parts can be shut down.

[0031] Under normal operating conditions, the central chilled water system 60 serves as the core cold source, providing chilled water to the auxiliary plant HVAC system 10, the containment ventilation and cooling system 30, the connecting plant HVAC system 40, and the diesel generator plant HVAC system 50. Its safety functions also include providing chilled water to the electrical and instrumentation control plant HVAC system 20, the equipment cooling water system 80, and the connecting plant HVAC system 40.

[0032] The central chilled water system 60 is configured in two rows, each consisting of a safety-grade sub-row and a non-safety-grade sub-row. During normal unit operation, all safety-grade chillers in the central chilled water system 60 are in operation, while the non-safety-grade sub-rows operate with one row running and the other on standby. The chilled water circulation pump 70 and its corresponding chiller are controlled by a synchronized start-stop strategy. In case of unit failure, if the final heat sink is partially or completely lost, the central chilled water system 60 can be supplied with cooling water by the equipment cooling water system 80; if the equipment cooling water system 80 is unavailable, the central chilled water system 60 will lose its system function. In the event of a loss of non-emergency AC power, the safety-grade equipment of the central chilled water system 60 will be powered by an emergency diesel generator, while other non-safety-grade equipment will cease operation.

[0033] Compared to large nuclear power plants, small modular reactors (SMRs) lack multiple redundancy configurations in their HVAC systems and are limited by plant volume, resulting in a more restrictive margin for ambient temperature regulation. This places higher demands on the reliability of the central chilled water system. Based on these technical characteristics of SMRs, this invention proposes a complete method for safe operation, ensuring the reactor's safe and stable operation under various conditions through environmental monitoring and tiered intervention.

[0034] This invention provides a method for the safe operation of a nuclear reactor, including: selecting areas within the nuclear island where system equipment used to achieve reactivity control, residual heat removal, and radioactive containment functions are located as environmental monitoring points based on the functional analysis and safety evaluation principles of the nuclear island system; monitoring environmental parameters in the selected areas; and comparing the monitored environmental parameters with preset multi-level parameter thresholds or multi-level parameter threshold ranges. Based on the comparison results, corresponding reactor operation status intervention operations are triggered; among them, when the support system capacity is limited, preset resource allocation conditions are executed to prioritize the operating environment of the minimum set of equipment required to achieve basic nuclear safety functions.

[0035] It should be noted that this case aims to address the operational safety issues of compact small reactors due to their low HVAC system redundancy and small environmental parameter adjustment margins. This method, through systematic environmental monitoring and a tiered intervention mechanism, ensures timely adjustments to the reactor's operating status when environmental parameters become abnormal, thereby guaranteeing nuclear safety.

[0036] The nuclear island system is the collective term for all systems and facilities within a nuclear power plant involved in nuclear reactions, nuclear fuel, and radioactive containment. Based on the principles of functional analysis and safety assessment of the nuclear island system, areas within the nuclear island containing systems and equipment used to achieve reactivity control, residual heat removal, and radioactive containment functions are selected as environmental monitoring points. Functional analysis involves identifying systems and equipment critical to nuclear safety, such as the reactivity control system (including control rod drive mechanisms and boric acid injection equipment), the residual heat removal system (including the primary loop residual heat removal system and the secondary side residual heat removal system), and the radioactive containment system (including the containment vessel and its associated isolation facilities). The safety assessment principles, based on the defense-in-depth concept, prioritize areas that play a critical role in maintaining safety functions under accident conditions, such as the containment vessel interior, electrical and instrumentation buildings, connection buildings, auxiliary buildings, and diesel generator buildings. Optionally, the selection of monitoring points can be based on equipment risk ratings or operational importance indicators, such as determining priority by quantitatively analyzing the contribution of equipment failures to safety functions. The environmental monitoring points include temperature sensors located inside the containment building, humidity monitoring points in the electrical and instrumentation control building, and pressure sensors connected to the building, thereby achieving comprehensive coverage of the environmental conditions in different areas.

[0037] Monitoring environmental parameters in the selected area involves real-time data collection of temperature, humidity, or pressure via a sensor network deployed within the nuclear island. The selection of environmental parameters is based on their impact on equipment operational reliability; for example, high temperatures may cause mechanical equipment to expand or electrical insulation performance to deteriorate. Alternative implementations may employ periodic sampling or event-triggered acquisition, and sensor types may include thermocouples, capacitive humidity sensors, or piezoelectric pressure sensors. The environmental parameters include temperature, relative humidity, and absolute pressure, ensuring the diversity and redundancy of monitoring.

[0038] The monitored environmental parameters are compared with preset multi-level threshold values, for example, through the logic processing unit of the control system. These multi-level thresholds are set based on equipment operating limits and personnel habitability requirements. For example, a primary threshold of approximately 55°C is set for the ambient temperature inside the containment as an early warning, and a secondary threshold of approximately 100 to 120°C is set as an emergency action baseline. Optionally, the threshold comparison can be implemented through software algorithms or hardware circuits, such as embedding comparison logic in a distributed control system or using a dedicated safety controller for real-time judgment. The multi-level threshold values ​​include early warning thresholds, action thresholds, and accident thresholds, with each threshold corresponding to a different response level, thus providing a progressive intervention mechanism.

[0039] Based on the comparison results, corresponding reactor operation status intervention operations are triggered, for example, by generating control signals to drive actuators. For instance, when environmental parameters exceed a Level 1 threshold, an alarm is triggered and the backup HVAC system is activated; if they exceed a Level 2 threshold or fail to recover within a certain time, reactor power is reduced or a shutdown is initiated; if they exceed a Level 3 threshold, an emergency shutdown is directly triggered and the accident handling procedure is initiated. Furthermore, intervention operations can be partially automated or fully manual, such as implementing a shutdown after operator confirmation, or having an emergency shutdown sequence automatically triggered by the protection system. These reactor operation status intervention operations include audible and visual alarms, backup system switching, power reduction control, normal shutdown, and emergency shutdown, thus forming a multi-level operation response system.

[0040] When the capacity of the support system is limited, preset resource allocation conditions are executed to prioritize the operating environment of the minimum set of equipment required to achieve the basic nuclear safety functions. The support system includes one or more of the following: HVAC system, cooling system, and emergency power system. Typical scenarios with limited capacity include loss of external power or a plant-wide power outage. The preset resource allocation conditions dynamically allocate available resources based on priority. For example, in the event of a loss of external power, after the emergency diesel generator starts, it prioritizes supplying power and cooling to the HVAC subsystems of the electrical and instrumentation control building, the connection building, and the diesel generator building, while maintaining the low-flow exhaust function of the auxiliary buildings. Optionally, resource allocation can be implemented through preset load offloading logic or real-time optimization algorithms. The minimum set of equipment includes the core emergency cooling system, the residual heat removal system, the equipment cooling water system 80, the important plant water system, and the emergency power distribution and instrumentation control equipment that support them, thereby ensuring the sustainability of the three basic safety functions: reactivity control, residual heat removal, and radioactive containment.

[0041] This invention addresses the issue of decreased equipment reliability in compact small reactors (SSDs) caused by rising ambient temperatures. By real-time monitoring of environmental parameters in key areas of the nuclear island, these parameters serve as direct feedback variables for reactor operation. A tiered response is achieved through multi-level parameter threshold comparisons: when environmental parameters become abnormal, an early warning system and backup system activation are triggered first. If parameters continue to deteriorate, the response escalates to power reduction, reactor shutdown, or emergency shutdown. Simultaneously, when support system capacity is limited, resources are dynamically allocated to prioritize the operating environment of the smallest equipment set, thus constructing a closed-loop control system from early warning to intervention. This method effectively improves the operational safety of SSDs, avoids chain reactions that may be caused by HVAC system failures, and enhances economy and adaptability through intensive resource utilization. It is particularly suitable for remote areas or isolated grid operation scenarios.

[0042] As an optional embodiment of this case, the step of comparing the monitored environmental parameters with preset multi-level parameter thresholds and triggering corresponding reactor operation status intervention operations based on the comparison results includes: When environmental parameters reach the first-level threshold, the first intervention operation, including alarm and / or activation of the backup system, is triggered. If environmental parameters fail to recover to below the first-level threshold within a preset time after reaching the first-level threshold, a second intervention operation, including reducing reactor power or performing a reactor shutdown, is triggered. When environmental parameters reach a second-level threshold that is higher than the first-level threshold, a third intervention operation is triggered, including an emergency shutdown and initiation of the incident handling procedure.

[0043] It should be noted that by establishing a correspondence between multi-level parameter thresholds and graded intervention operations, a more refined environmental risk control mechanism is provided for compact small reactors. When environmental parameters reach the first-level threshold, the first intervention operation is triggered, including alarm and / or activation of backup systems and / or initiation of maintenance to restore normal environmental parameters. The alarm operation can be specifically implemented as activation of audible and visual alarm devices or alarm information prompts in the control room. Activation of backup systems includes putting into operation backup HVAC units or switching to redundant ventilation loops. The first intervention operation can also be achieved through soft alarms in the distributed control system combined with manual activation of backup equipment after operator confirmation. The first intervention operation includes local audible and visual alarms, remote monitoring alarms, activation of backup chiller units, and operation of backup ventilation fans, thus forming a diversified primary response mechanism. If environmental parameters do not return to the normal range within a preset time after reaching the first-level threshold, the second intervention operation is triggered, including reducing reactor power or performing a reactor shutdown. The first-level threshold is set based on the equipment's tolerance limits and safety margins; for example, the first-level threshold for the electrical and instrumentation control room is set between 35 and 45°C. Reducing reactor power can be achieved through control rod regulation or turbine load control, while shutdown operations include initiating a normal shutdown sequence. The second intervention operation can be dynamically adjusted based on the duration of parameter exceeding limits; for example, automatically triggering power reduction if the power does not recover within a preset time window, or directly executing a shutdown through safety system interlocks. The second intervention operation includes gradually reducing the load to 50% of rated power, rapidly reducing the load to hot standby, and triggering a normal shutdown protection sequence, thereby providing a gradual power control strategy. The preset time is determined based on the thermal inertia of the equipment, for example, 10-30 minutes; the predetermined rate threshold is determined based on thermal-hydraulic analysis, for example, a temperature increase of 5-10°C per minute. Specific values ​​can be adjusted according to reactor type characteristics and equipment configuration.

[0044] If environmental parameters deteriorate further to the second-level threshold, exceeding the first-level threshold, a third intervention is triggered, including an emergency shutdown and initiation of the accident handling procedure. The second-level threshold typically corresponds to safety limits under accident conditions, such as a containment ambient temperature set at 100 to 120°C. An emergency shutdown is achieved by triggering the reactor protection system, while the accident handling procedure initiates predefined accident protocols, such as commissioning the residual heat removal system or activating the safety injection system. The third intervention can be based on a multi-parameter composite judgment, such as combining temperature and pressure parameters for triggering. The third intervention includes rapid control rod insertion, emergency boron injection, activation of the post-accident monitoring system, and execution of severe accident management guidelines, thereby ensuring the rapid termination of the nuclear chain reaction and control of accident consequences under extreme conditions. This case overcomes the lag in fault response caused by the limited environmental conditioning margin of small modular reactors (SMRs). Through early intervention and a phased escalation strategy, it effectively avoids equipment malfunctions caused by uncontrolled environmental parameters. This enhances the safety and resilience of SMR operation, preventing unnecessary economic losses from shutdowns and ensuring timely and decisive measures to protect core safety under severe conditions.

[0045] As an optional embodiment of this case, in the step of triggering a third intervention operation, including emergency reactor shutdown and initiation of accident handling procedures, when environmental parameters reach a second-level threshold higher than the first-level threshold, When the third intervention operation is triggered, if the abnormal rate of increase of environmental parameters exceeds a predetermined rate threshold, or if the environmental parameters exceed a predetermined leakage threshold used as a leakage criterion, a diagnostic signal for potential high-temperature or radioactive abnormal fluid leakage is generated simultaneously and a leakage emergency procedure is triggered.

[0046] It should be noted that if the abnormal rate of increase of environmental parameters exceeds a predetermined rate threshold, or if the environmental parameters exceed a predetermined leakage threshold used as a leakage criterion, a diagnostic signal for potential abnormal temperature fluid leakage is generated, triggering a leakage emergency procedure. The abnormal rate of increase is determined by calculating the change in environmental parameters per unit time; for example, a temperature increase exceeding 5°C per minute exceeds the rate threshold. The leakage criterion sets independent thresholds for specific areas; for example, an ambient temperature exceeding 75-80°C in a connected plant is considered a potential leakage signal. The abnormal rate of increase can be detected using a moving average algorithm or a differential circuit, and the leakage criterion can be combined with humidity parameters for a composite judgment. The triggering conditions include temperature change rate monitoring, pressure surge detection, and abnormal trend judgment based on pattern recognition, thereby enhancing the reliability of the triggering mechanism.

[0047] When the above conditions are met, the system generates a diagnostic signal for potential abnormal temperature fluid leakage and triggers the leakage emergency procedure. The diagnostic signal can be generated through a dedicated diagnostic module or a safety-grade instrumentation and control system. The leakage emergency procedure includes isolating the suspected leak area, initiating emergency cooling, or activating radioactive containment measures. The diagnostic signal can be integrated into the power plant's computerized operation support system, and the leakage emergency procedure can dynamically adjust the response level based on leakage probability assessment. Diagnosis and emergency response include leak alarm signal generation, automatic isolation valve closure, emergency ventilation system activation, and execution of accident consequence assessment procedures, thus forming a complete leakage response chain. This case, by introducing dynamic parameter change characteristics and specific leakage criteria, achieves early identification and accurate response to potential accidents, improves the system's ability to perceive latent faults (such as minor leaks) and rapidly deteriorating operating conditions, and avoids missing the optimal intervention opportunity due to the delay of traditional threshold detection. It enhances the prevention and mitigation capabilities of small modular reactor accidents, and through the combination of early diagnosis and targeted emergency procedures, significantly reduces the probability and consequences of serious accidents.

[0048] As an optional embodiment of this case, in the step of comparing the monitored environmental parameters with preset multi-level parameter thresholds, the method for setting the multi-level parameter thresholds includes: For each monitoring area, obtain the safe operating temperature limit for each device within that area; Based on the envelope principle, the lowest value among all equipment temperature limits is selected as the unified threshold benchmark for the region, and the unified threshold benchmark is checked and adjusted taking into account the requirements for human habitability.

[0049] It should be noted that for each monitoring area, the safe operating temperature limits for each piece of equipment within that area need to be obtained. These limits are derived from technical specifications provided by equipment manufacturers, industry standard recommendations, or reliable data based on experimental verification. For example, an electrical instrumentation and control plant may contain equipment such as batteries, instrumentation and control cabinets, and distribution panels, and their maximum allowable operating temperatures need to be obtained separately. Optionally, the safe operating temperature limits for equipment can be obtained through equipment tolerance testing or statistical analysis based on historical operating data. Safe operating temperature limits may include, for example, temperature resistance limits for insulation materials of electronic equipment, allowable limits for thermal expansion of mechanical components, and upper limits for the operating temperature of lubrication systems, thereby ensuring coverage of the critical temperature constraints of various types of equipment.

[0050] Based on the envelope principle, the lowest temperature limit among all equipment is selected as the unified threshold benchmark for the area. This unified threshold benchmark is then checked and adjusted considering personnel occupancy requirements. In special cases, the threshold setting can be appropriately adjusted according to the severity of equipment failure consequences. The envelope principle is implemented by comparing the temperature limits of all equipment within the area and selecting the most stringent limit as the unified benchmark. For example, when an area contains both instrumentation equipment with a limit of 45°C and batteries with a limit of 35°C, the unified threshold benchmark is set to 35°C. Personnel occupancy requirements are based on the environmental conditions that personnel can tolerate during operation. For example, the temperature threshold of the main control room must simultaneously meet the equipment operation requirements and the comfort range for long-term personnel residence. The unified threshold benchmark includes equipment protection thresholds, personnel comfort thresholds, and system safety thresholds, thereby constructing a comprehensive threshold system that balances equipment reliability and personnel operability. This case overcomes the shortcomings of traditional threshold settings, which may result in insufficient protection or excessive conservatism. The envelope principle ensures that the weakest link is adequately protected, while combining personnel occupancy requirements to achieve human-machine collaborative optimization. The scientific and rational nature of the threshold setting has been improved, ensuring that all equipment operates within a safe temperature range and that personnel can effectively perform intervention operations in case of accidents, thereby enhancing the overall safety and reliability of the small modular reactor.

[0051] As an optional embodiment of this case, in the step of executing preset resource allocation conditions to prioritize the operating environment of the minimum set of devices required to achieve basic nuclear safety functions when the support system capacity is limited, the preset resource allocation conditions include: In the event of a loss of external power, the emergency diesel generator system is activated, and available cooling and electrical resources are preferentially allocated to the HVAC subsystem that provides environmental protection for the minimum equipment assembly.

[0052] It should be noted that this strategy ensures environmental protection for the minimum equipment set by optimizing emergency resource allocation. In the event of a loss of external power, an emergency diesel generator system is activated. This system includes diesel generator sets and their associated fuel supply and control units. Gas turbines or energy storage systems can also be used as backup power sources. The emergency diesel generator system includes both rapid start-up and continuous operation of diesel generator sets, thus providing diversified emergency power guarantees.

[0053] Available cooling and electrical resources are prioritized for allocation to the HVAC subsystem, which provides environmental protection for the smallest unit of equipment. This allocation is achieved through power switching devices and valve control. Available cooling sources include chilled water generated by the central chilled water system 60 or natural cooling sources, while electrical resources refer to the limited electrical energy output from the emergency diesel generator system. Resource allocation can be dynamically adjusted through preset priority logic or real-time load calculation. The HVAC subsystem includes the electrical and instrumentation control plant air conditioning system, the containment circulation cooling system, and the diesel generator plant ventilation system, ensuring environmental control in critical areas.

[0054] This case demonstrates how resource priority management in emergency situations enables the optimal allocation of limited resources, maintaining basic safety functions even when system capacity is constrained. This enhances the survivability of small reactors in the event of power loss accidents. By ensuring the operating environment of the minimum equipment set, it ensures the safe withdrawal of the reactor to a shutdown state and prevents the accident from worsening.

[0055] As an optional embodiment of this case, the step of preferentially allocating available cold sources and power resources to the HVAC subsystem that provides environmental protection for the minimum equipment set includes: Control the central chilled water system to stop supplying cooling to non-safety-level users; Ensure that chilled water is supplied to the HVAC systems of the electrical instrumentation and control plant, the connection plant, and the diesel generator plant; Maintain at least some of the exhaust ventilation functions of the auxiliary plant.

[0056] It should be noted that, firstly, the central chilled water system 60 is controlled to stop supplying cooling to non-safety-level users. This operation is achieved by closing the electrically operated isolation valves of the corresponding branches or adjusting the operating status of the water pumps. Non-safety-level users include non-essential office area air conditioning or general equipment room cooling systems, and the supply of cooling sources can be limited through pressure regulation or flow distribution. Non-safety-level users include administrative office building air conditioning, general warehouse ventilation, and non-critical equipment cooling devices, ensuring that limited cooling sources are concentrated in safety-critical areas.

[0057] Ensure the supply of chilled water to the HVAC systems of the electrical and instrumentation control building, connection building, and diesel generator building. These buildings house critical equipment such as reactor protection systems, waste heat removal equipment, and emergency power supplies. Chilled water supply is achieved by maintaining the operation of chilled water circulation pump 70 and keeping heat exchangers 100 operational. The critical building HVAC systems include the air conditioning system in the electrical equipment room, the mechanical ventilation system in the connection building, and the cooling system in the diesel generator room, forming a comprehensive protection system for the core equipment.

[0058] Maintaining at least partial exhaust ventilation functionality in auxiliary buildings is achieved by keeping exhaust fans operational or activating backup ventilation paths, particularly in areas where hydrogen or radioactive gases may accumulate. Natural ventilation or passive exhaust systems can be used as supplementary means. Exhaust functions include hydrogen monitoring exhaust, radioactivity control area exhaust, and heat load area exhaust, ensuring the timely removal of hazardous materials. This project addresses how to maintain basic environmental control capabilities under conditions of limited cooling and power, thereby maximizing the use of limited resources, preventing the loss of safety system functionality due to deteriorating environmental conditions, and enhancing the resilience of small modular reactors under extreme operating conditions.

[0059] As an optional embodiment of this case, in the step of executing preset resource allocation conditions to prioritize the operating environment of the minimum set of devices required to achieve basic nuclear safety functions when the support system capacity is limited, the preset resource allocation conditions further include: In the event of a plant-wide power outage, all power-off generator sets, such as diesel generators or other generator sets, are started, and the ventilation function that provides environmental protection for the minimum set of equipment is gradually restored based on a preset sequence determined by the safety importance of the equipment and system dependencies.

[0060] It should be noted that in the event of a plant-wide power outage, the specially configured plant-wide power outage diesel generator set will be activated first. This unit differs from conventional emergency diesel generator sets; it possesses black-start capability and is specifically designed to handle severe accidents involving a complete loss of AC power to the entire plant. The plant-wide power outage diesel generator set can be started via a battery energy storage system or by using a gas turbine as a backup starting power source. The plant-wide power outage diesel generator set includes fast-response diesel generator sets, continuous power output diesel generator sets, and intelligent generator sets with autonomous control functions, ensuring reliable power supply under extreme operating conditions.

[0061] The strategy of gradually restoring ventilation functions to provide environmental protection for the minimum equipment set in a preset order is implemented through programmatic load switching logic. The preset order is determined based on the safety importance of the equipment and system dependencies, and can be dynamically adjusted through real-time system status assessment, or improved by using a partitioned parallel restoration approach. Ventilation functions include mechanical forced ventilation, natural convection ventilation, and a hybrid ventilation system, forming a multi-layered ventilation protection system. This case establishes a progressive restoration path from basic power to core safety by orderly restoring critical ventilation functions, avoiding system overload or delays in critical function restoration caused by disordered power supply in the initial stage of a plant-wide power outage. This ensures that the small modular reactor (SMR) can maintain the most basic safety barrier under extreme accident conditions, creating the necessary conditions for the restoration of core safety functions.

[0062] As an optional embodiment of this case, in the step of starting the plant-wide power-off diesel generator set during a plant-wide power outage and gradually restoring the ventilation function to provide environmental protection for the minimum equipment set in a preset order, the step of gradually restoring the ventilation function in a preset order includes: First, restore ventilation in the diesel generator room; then restore ventilation in the electrical and instrumentation control room and the connecting room; then restore the minimum exhaust function of the auxiliary room; on this basis, start at least the safety injection system and the waste heat removal system.

[0063] It should be noted that during a plant-wide power outage, ventilation functions are restored in a preset sequence, generally following a sequential restoration logic. However, under specific operating conditions, the restoration rhythm can be adjusted appropriately based on the system status: First, ventilation in the diesel generator room is restored. This step is achieved by activating the diesel generator room ventilation system to ensure the generator sets operate stably at suitable temperatures. Enhanced natural ventilation or backup ventilation circuits can be used as supplementary measures. Next, ventilation in the electrical and instrumentation control room and connecting rooms is restored. These two rooms house the reactor protection system and critical auxiliary equipment, and their ventilation restoration is accomplished by activating the corresponding air conditioning systems and ventilation devices. Ventilation in the most urgently needed areas can be restored first, based on the equipment temperature status. Ventilation in the electrical and instrumentation control room and connecting rooms includes the control room air conditioning system, the electrical equipment room ventilation system, and the connecting room mechanical ventilation system. Then, the minimum exhaust function of the auxiliary rooms is restored. This function is mainly for areas where harmful gases may accumulate, achieved by activating critical exhaust fans or enabling backup exhaust paths. The minimum exhaust function includes exhaust in the hydrogen monitoring area, exhaust in the radioactive area, and exhaust in the high-temperature area. Based on this, at least the safety injection system and the waste heat removal system should be put into operation. After ensuring that the necessary ventilation environment is established, the secondary waste heat removal system or the primary waste heat removal system should be put into operation.

[0064] The safety injection system is a crucial component of the nuclear reactor safety system. It is primarily used to inject boron-containing cooling water or other cooling media into the reactor core during accident conditions (such as coolant leakage accidents or pipe ruptures) to achieve at least one of the following key safety functions: core cooling, reactivity control, pressure control, and radioactive containment. Core cooling prevents core overheating and fuel rod damage, ensuring timely removal of core heat. Reactivity control suppresses nuclear chain reactions through the injection of boron-containing water, assisting in rapid reactor shutdown and maintaining a subcritical state. Pressure control helps maintain or restore the pressure boundary integrity of the reactor coolant system. Radioactive containment serves as part of defense-in-depth, reducing the risk of radioactive material release. This case addresses the technical challenge of scientifically and rationally rebuilding the safety barrier under limited power resources after a plant-wide power outage. Through an orderly functional recovery process, it maximizes the use of limited resources, ensures the residual heat removal system operates in a suitable environment, and prevents the risk of core overheating.

[0065] As an optional embodiment of this case, the minimum equipment set includes: a core emergency cooling system, a secondary and primary circuit residual heat removal system, a system for providing equipment cooling for the safety system, a system for providing plant water for the final heat sink, and a support system for providing chilled water, emergency power and uninterrupted power for the above functions.

[0066] It should be noted that this set of equipment includes a core emergency cooling system, whose function is to inject cooling water into the core during accident conditions to prevent fuel rod overheating and damage. Secondary and primary coolant removal systems are responsible for continuously removing decay heat after shutdown, maintaining the core temperature within a safe range. Systems providing equipment cooling for safety systems are implemented through equipment cooling water system 80, transferring heat generated by safety equipment to the final heat sink. Systems providing plant water to the final heat sink obtain cooling water from external water sources through the critical plant water system. Support systems providing chilled water, emergency power, and uninterruptible power for the above functions include a central chilled water system 60, an emergency diesel generator system, and DC and AC uninterruptible power supply systems. The minimum equipment set can be adjusted according to the specific reactor design, but must cover the three basic safety functions: reactivity control, residual heat removal, and radioactive containment. This addresses the need to clearly define the scope of critical equipment that must be prioritized under resource constraints, provides clear guidance for emergency resource allocation, ensures that the most basic nuclear safety functions are maintained under any operating condition, and prevents further escalation of the accident.

[0067] As an optional embodiment of this case, in the step of monitoring the environmental parameters of the selected area, a delayed judgment is introduced in the processing of the environmental temperature monitoring data to avoid accidental triggering of intervention operations due to instantaneous fluctuations.

[0068] It should be noted that the delay judgment is achieved by setting a reasonable time delay window. For example, the trigger condition is only confirmed after the temperature exceeds a threshold and remains there for a certain period of time. The delay judgment includes fixed-time delay, adjustable-time delay, and intelligent delay judgment based on parameter change trends, providing diverse anti-false alarm mechanisms. By verifying and eliminating instantaneous interference signals in the time dimension, the technical problem solved is to avoid unnecessary system responses caused by instantaneous fluctuations or interference signals from sensors, thereby improving the reliability and stability of the monitoring system. While ensuring that genuine anomalies are responded to in a timely manner, it effectively prevents false alarms and malfunctions, improving the safety and economy of small modular reactor operation.

[0069] This invention provides a safe operation system for a nuclear reactor, comprising: The parameter acquisition module is distributed throughout the nuclear island, in the area where the system equipment used to implement basic nuclear safety functions is located. The analysis and control module is communicatively connected to the parameter acquisition module, and the analysis and control module is configured as follows: The environmental parameters collected by the parameter acquisition module are compared with the pre-stored multi-level parameter thresholds; A control signal is generated based on the comparison results; The operation execution module is communicatively connected to the analysis and control module. The operation execution module is configured to perform corresponding operations in response to the control signal. The operations include one or more of the following: alarm operation, standby system start-up and shutdown operation, reactor power reduction, shutdown, or emergency shutdown operation.

[0070] It should be noted that the parameter acquisition modules are distributed throughout the nuclear island, in areas housing systems and equipment essential for nuclear safety functions. These areas include the containment building, electrical and instrumentation control buildings, and connection buildings. The parameter acquisition modules acquire environmental parameters in real time via a sensor network, employing either wired or wireless sensor networks. The higher-level parameter acquisition module comprises a temperature sensor array, a humidity monitoring terminal, and a pressure detection device, forming a multi-dimensional environmental parameter acquisition system. The analysis and control module communicates with the parameter acquisition modules and is configured to perform data comparison and decision-making logic. The analysis and control module compares the environmental parameters acquired by the parameter acquisition modules with pre-stored multi-level parameter thresholds; this process is implemented through built-in algorithms or dedicated computing units. Based on the comparison results, control signals are generated, the content of which corresponds to the degree to which the parameters exceed limits. The analysis and control module includes a threshold comparison unit, a logic judgment unit, and a control signal generation unit, forming a complete analysis and decision-making chain. The operation execution module communicates with the analysis and control module and is configured to perform corresponding operations in response to the control signals. The operations include one or more of the following: alarm operations, standby system start-up and shutdown operations, and reactor power reduction, shutdown, or emergency shutdown operations. Alarm operations are implemented through audible and visual alarm devices or human-machine interface prompts. Standby system start-up and shutdown operations control the switching on and off of standby ventilation equipment or chiller units. Reactor status control operations are completed by adjusting control rods or triggering the protection system. In alternative embodiments, the operation execution module can use relay hardwiring or bus communication to execute control commands. This invention enables rapid detection and automatic response to environmental anomalies in small modular reactors, thereby improving the timeliness and reliability of safety responses. Through systematic module division of labor and cooperation, it effectively prevents safety incidents caused by uncontrolled environmental parameters and enhances the overall safety performance of small modular reactors.

[0071] As an optional embodiment of this case, the analysis and control module is integrated as a functional module into the distributed control system of the nuclear reactor; The environmental parameters are used as multiple direct process variables in the distributed control system to participate in the control logic operation. When the environmental parameters exceed the preset safety limit, the control signal can automatically trigger the reactor shutdown protection action.

[0072] It should be noted that the distributed control system provides a unified data processing platform and communication network. Environmental parameters, as a direct process variable of the distributed control system, are connected to the system through analog input modules or digital communication interfaces and participate in control logic operations. The distributed control system includes field control stations, operator stations, and engineer stations, forming a hierarchical control architecture. Control signals can automatically trigger reactor shutdown protection actions; this function is achieved through the interface between the distributed control system and the reactor protection system. When environmental parameters exceed preset safety limits, the control system generates a shutdown command and transmits it to the protection system actuators.

[0073] As an optional embodiment of this case, the analysis and control module is further configured as follows: When the capacity of the support system (including HVAC system, cold source system or emergency power system) is limited, a resource allocation control signal is generated; The operation execution module also includes a resource allocation execution unit, configured to respond to the resource allocation control signal and preferentially allocate available resources to the HVAC subsystem that provides environmental protection for the minimum set of equipment.

[0074] It should be noted that when a limited capacity is detected in the support system (including HVAC systems, chilled water systems, or emergency power systems), a resource allocation control signal is generated. Capacity limitation is identified based on system operating status monitoring, such as insufficient chilled water flow or reduced power supply capacity. The analysis and control module determines the capacity status by analyzing system parameters. Capacity limitation identification includes chilled water capacity monitoring, power load analysis, and equipment status assessment, forming a comprehensive system capacity assessment mechanism. The operation execution module also includes a resource allocation execution unit, which is configured to respond to the resource allocation control signal and prioritize the allocation of available resources to the HVAC subsystems that provide environmental support for the minimum equipment set. Resource allocation is achieved by switching power supply circuits, adjusting valve openings, or reallocating chilled water. The resource allocation execution unit includes a power switching device, valve control mechanism, and chilled water allocation unit, ensuring that limited resources are accurately allocated to the most critical systems.

[0075] The present invention provides a computer-readable storage medium having computer-readable instructions stored thereon, which, when executed by a computer's processor, cause the computer to perform the steps of the method.

[0076] It should be noted that storage media include, but are not limited to, various carriers capable of storing program code, such as optical discs, flash memory, and hard disks. Computer-readable storage media include solid-state drives, optical disc arrays, and tape libraries, providing diverse storage solutions. By transforming secure operation methods into repeatable program flows through software, the standardization and portability of secure operation methods are achieved, improving the convenience and consistency of method implementation. Programmed execution eliminates the uncertainty of human factors, ensuring that secure operation methods can be accurately and reliably implemented under various operating conditions.

[0077] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A method for the safe operation of a nuclear reactor, characterized in that, include: Based on the principles of functional analysis and safety evaluation of the nuclear island system, the areas where the system equipment within the nuclear island system used to achieve reactivity control, residual heat removal and radioactive containment functions are located are selected as environmental monitoring points. Monitor environmental parameters of the selected area, including at least temperature parameters; The monitored environmental parameters are compared with preset multi-level parameter thresholds; Based on the comparison results, trigger corresponding reactor operation status intervention operations; When the system capacity is limited, preset resource allocation conditions are executed to prioritize the operating environment of the minimum set of equipment required to achieve basic nuclear safety functions.

2. The method for safe operation of a nuclear reactor according to claim 1, characterized in that, The monitored environmental parameters are compared with preset multi-level parameter thresholds; The steps to trigger corresponding reactor operation status intervention operations based on the comparison results include: When the environmental parameters reach the first-level threshold, a first intervention operation is triggered, including alarm and / or activation of the backup system and / or initiation of maintenance to restore normal environmental parameters. If the environmental parameters do not recover to below the first-level threshold within a preset time after reaching the first-level threshold, a second intervention operation is triggered, including reducing reactor power or performing a reactor shutdown. When the environmental parameters reach a second-level threshold that is higher than the first-level threshold, a third intervention operation is triggered, including an emergency reactor shutdown and initiation of the incident handling procedure.

3. The method for safe operation of a nuclear reactor according to claim 2, characterized in that, The step of triggering a third intervention operation, including emergency reactor shutdown and initiation of accident handling procedures, when the environmental parameter reaches a second-level threshold higher than the first-level threshold includes: When the third intervention operation is triggered, if the abnormal rate of increase of the environmental parameter exceeds a predetermined rate threshold, or if the environmental parameter exceeds a predetermined leakage threshold used as a leakage criterion, a diagnostic signal for potential abnormal fluid leakage is generated simultaneously and a leakage emergency procedure is triggered.

4. The method for safe operation of a nuclear reactor according to claim 1, characterized in that, In the step of comparing the monitored environmental parameters with preset multi-level parameter thresholds, the method for setting the multi-level parameter thresholds includes: For each monitoring area, obtain the safe operating temperature limit for each device within that area; Based on the envelope principle, the lowest value among all equipment temperature limits is selected as the unified threshold benchmark for the region, and the unified threshold benchmark is checked and adjusted taking into account the requirements for human habitability.

5. The method for safe operation of a nuclear reactor according to claim 1, characterized in that, In the step of executing preset resource allocation conditions to prioritize the operating environment for the minimum set of devices required to achieve basic nuclear safety functions when the support system capacity is limited, the preset resource allocation conditions include: In the event of a loss of external power, the emergency power generation system is activated, and available cooling and electrical resources are preferentially allocated to the HVAC subsystem that provides environmental protection for the minimum equipment assembly.

6. The method for safe operation of a nuclear reactor according to claim 5, characterized in that, The step of prioritizing the allocation of available cooling and electrical resources to the HVAC subsystem that provides environmental protection for the minimum equipment set includes: Control the central chilled water system to stop supplying cooling to non-safety-level users; Ensure that chilled water is supplied to the HVAC systems of the electrical instrumentation and control plant, connection plant, and generator plant; Maintain at least some of the exhaust ventilation functions of the auxiliary plant.

7. The method for safe operation of a nuclear reactor according to claim 1, characterized in that, In the step of executing preset resource allocation conditions to prioritize the operating environment for the minimum set of devices required to achieve basic nuclear safety functions when the support system capacity is limited, the preset resource allocation conditions further include: In the event of a plant-wide power outage, the plant's generator sets will be started and the ventilation function, which provides environmental protection for the minimum equipment set, will be gradually restored in a preset sequence.

8. The method for safe operation of a nuclear reactor according to claim 7, characterized in that, In the step of starting all the plant's generator sets during a power outage and gradually restoring the ventilation function to provide environmental protection for the minimum equipment set in a preset sequence, the step of gradually restoring the ventilation function in a preset sequence includes: First, restore ventilation in the generator room; Then, ventilation was restored in the electrical control and instrumentation workshop and the connecting workshop; Then restore the minimum ventilation function of the auxiliary plant; Based on this, at least the safety injection system and the waste heat removal system should be started.

9. A safe operation system for a nuclear reactor, characterized in that, include: The parameter acquisition modules are distributed throughout the nuclear island in the areas where system equipment for implementing basic nuclear safety functions is located. The analysis and control module is communicatively connected to the parameter acquisition module, and the analysis and control module is configured as follows: The environmental parameters collected by the parameter acquisition module are compared with the pre-stored multi-level parameter thresholds; A control signal is generated based on the comparison results; The operation execution module is communicatively connected to the analysis and control module. The operation execution module is configured to perform corresponding operations in response to the control signal. The operations include multiple operations such as alarm operation, standby system start-up and shutdown operation, maintenance operation, reactor power reduction, reactor shutdown or emergency shutdown operation.

10. A computer-readable storage medium, characterized in that, It stores computer-readable instructions that, when executed by a computer's processor, cause the computer to perform the steps of the method according to any one of claims 1-8.

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