Control method and device for mitigating SGTR accidents in pressurized water reactor nuclear power plants, and pressurized water reactor in nuclear power plants

Abstract

The present invention relates to a control method and device for mitigating SGTR accidents in pressurized water reactor nuclear power plants, and a pressurized water reactor in the nuclear power plant. The method comprises: S1, monitoring the radioactive activity outside the secondary circuit when the primary circuit is operating normally, wherein the primary circuit is maintained in normal operation by a charging pump; S2, triggering a lockout of a flow increase injection signal of a chemical and volume control system when the radioactive activity is greater than or equal to a first preset value, thereby shutting off the output of the flow increase injection signal, wherein the charging pump of the chemical and volume control system is used to trigger flow increase based on the flow increase injection signal; S3, monitoring the loop pressure of the primary circuit and triggering a safety injection signal when the loop pressure is less than or equal to a second preset value, thereby unlocking the flow increase injection signal of the chemical and volume control system based on the safety injection signal, thereby causing the chemical and volume control system to output the flow increase injection signal. The implementation of the present invention can increase the margin for SGTR accidents and improve the economic efficiency and safety of the power plant.

Description

Technical Field

[0001] The present invention relates to the field of nuclear power technology, and more particularly to a control method and device for mitigating SGTR accidents in a pressurized water reactor nuclear power plant, and a pressurized water reactor in the nuclear power plant. Background Art

[0002] To mitigate the consequences of a SGTR (steam generator tube rupture) accident, nuclear power plant operators manually isolate the damaged steam generator 30 minutes after detecting the accident, concentrating radioactive material releases on the damaged steam generator (SGa) before isolation. The period before SGa isolation is the plant's automatic operation phase, with key factors influencing the accident's consequences including initial plant parameters, shutdown signal settings, injection signal settings, steam generator water level protection settings, chemical and volumetric control system operation, and safety injection flow. Following an SGTR accident, the pressurizer water level gradually drops. To maintain the pressurizer water level and primary circuit pressure, the chemical and volumetric control systems automatically increase the top-up flow, resulting in increased rupture flow and atmospheric emissions, adversely affecting the consequences of the SGTR accident.

[0003] During the automatic action stage of the accident, the charging flow directly affects the pressure of the primary circuit, the stabilizer water level and the triggering time of the reactor protection signal. It is necessary to improve its design to reduce the radioactive release after the SGTR accident and improve the reliability and safety of the nuclear power plant. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a control method and device for alleviating SGTR accidents in a pressurized water reactor nuclear power plant, and a pressurized water reactor in the nuclear power plant.

[0005] The technical solution adopted by the present invention to solve the technical problem is to construct a control method for mitigating SGTR accidents in pressurized water reactor nuclear power plants, comprising the following steps:

[0006] S1. Monitoring the radioactive activity outside the secondary circuit when the primary circuit is operating normally, wherein the primary circuit is maintained in normal operation by a charging pump;

[0007] S2. When the radioactivity is greater than or equal to a first preset value, triggering a flow increase injection signal of a chemical and volume control system to shut down the output of the flow increase injection signal, wherein the chemical and volume control system is connected to the charging pump, and the charging pump is used to trigger flow increase according to the flow increase injection signal;

[0008] S3. Monitor the loop pressure of the first loop and trigger the generation of a safety injection signal when the loop pressure is less than or equal to a second preset value, so as to unlock the flow increase injection signal of the chemical and volume control system according to the safety injection signal, so that the chemical and volume control system outputs the flow increase injection signal.

[0009] Preferably, in the control method for mitigating SGTR accidents in pressurized water reactor nuclear power plants according to the present invention, the first preset value is greater than or equal to 1.0E 4 Bq / m 3 .

[0010] Preferably, in the control method for mitigating SGTR accidents in pressurized water reactor nuclear power plants according to the present invention, the second preset value is less than or equal to 11.5 MPa.

[0011] Preferably, the control method for mitigating SGTR accidents in pressurized water reactor nuclear power plants according to the present invention further includes:

[0012] When the radioactivity is greater than or equal to the first preset value, a preset protection signal is generated, and the preset protection signal is used to trigger the flow increase injection signal of the locking chemical and volume control system.

[0013] Preferably, in the control method for mitigating SGTR accidents in pressurized water reactor nuclear power plants according to the present invention, the charging pump comprises a single charging pump;

[0014] The primary circuit maintains normal operation through the sole charging pump;

[0015] The chemical and volume control system is connected to the only charging pump, and the only charging pump is used to trigger flow increase according to the flow increase injection signal to increase the flow of the primary circuit.

[0016] Preferably, in the control method for mitigating SGTR accidents in pressurized water reactor nuclear power plants according to the present invention, the charging pump comprises a main charging pump and a backup charging pump;

[0017] In the default state, the primary circuit maintains normal operation through the main charging pump;

[0018] The chemical and volume control system is connected to the standby charging pump, and the standby charging pump is used to trigger and start according to the flow increase injection signal to increase the flow of the primary circuit.

[0019] The present invention also provides a control device for mitigating SGTR accidents in pressurized water reactor nuclear power plants, comprising:

[0020] a radioactive activity monitoring unit, configured to monitor the radioactive activity outside the secondary circuit when the primary circuit is operating normally, wherein the primary circuit is maintained in normal operation by a charging pump;

[0021] a locking unit, configured to lock a flow increase injection signal of a chemical and volume control system when the radioactivity is greater than or equal to a first preset value, so as to shut off the output of the flow increase injection signal, wherein the chemical and volume control system is connected to the charging pump, and the charging pump is configured to trigger flow increase according to the flow increase injection signal;

[0022] a pressure monitoring unit, configured to monitor the circuit pressure of the primary circuit;

[0023] A locking unit is used to trigger the generation of a safety injection signal when the loop pressure is less than or equal to a second preset value, so as to unlock the flow increase injection signal of the chemical and volume control system according to the safety injection signal, so that the chemical and volume control system outputs the flow increase injection signal.

[0024] Preferably, in the control device for mitigating SGTR accidents in pressurized water reactor nuclear power plants described in the present invention, the locking unit is also used to trigger the generation of a preset protection signal when the radioactive activity is greater than or equal to the first preset value, and trigger the flow increase injection signal of the locking chemical and volume control system through the preset protection signal.

[0025] The present invention constructs a pressurized water reactor for a nuclear power plant, characterized by comprising a charging pump, a chemical and volume control system, a primary circuit and a secondary circuit, and a control device as described in any one of the above.

[0026] Preferably, in the pressurized water reactor of the nuclear power plant of the present invention,

[0027] The charging pump includes a single charging pump,

[0028] The primary circuit maintains normal operation through the sole charging pump;

[0029] The chemical and volume control system is connected to the only charging pump, and the only charging pump is used to trigger flow increase according to the flow increase injection signal to increase the flow of the primary circuit.

[0030] Preferably, in the pressurized water reactor of the nuclear power plant of the present invention,

[0031] The charging pump includes a main charging pump and a backup charging pump;

[0032] In the default state, the primary circuit maintains normal operation through the main charging pump;

[0033] The chemical and volume control system is connected to the standby charging pump, and the standby charging pump is used to trigger and start according to the flow increase injection signal to increase the flow of the primary circuit.

[0034] The control method and device for mitigating SGTR accidents in a pressurized water reactor nuclear power plant and the pressurized water reactor of the nuclear power plant according to the present invention have the following beneficial effects: increasing the margin for SGTR accidents and improving the economy and safety of the power plant. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The present invention will be further described below with reference to the accompanying drawings and embodiments, in which:

[0036] Figure 1 This is a flowchart of an embodiment of a control method for mitigating SGTR accidents in pressurized water reactor nuclear power plants according to the present invention;

[0037] Figure 2 The present invention is a logic block diagram of a control method for alleviating SGTR accidents in pressurized water reactor nuclear power plants. DETAILED DESCRIPTION

[0038] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, specific embodiments of the present invention are now described in detail with reference to the accompanying drawings.

[0039] like Figure 1As shown, in a first embodiment of a control method for mitigating SGTR accidents in a pressurized water reactor nuclear power plant according to the present invention, the method includes: S1. Monitoring the radioactive activity outside the secondary circuit when the primary circuit is operating normally, wherein the primary circuit is maintained in normal operation by a charging pump; S2. When the radioactive activity is greater than or equal to a first preset value, triggering a lockout of a flow increase injection signal of a chemical and volume control system to shut off the output of the flow increase injection signal, wherein the chemical and volume control system is connected to the charging pump, and the charging pump is configured to trigger flow increase based on the flow increase injection signal; S3. Monitoring the circuit pressure of the primary circuit and, when the circuit pressure is less than or equal to a second preset value, triggering a safety injection signal to unlock the flow increase injection signal of the chemical and volume control system based on the safety injection signal, causing the chemical and volume control system to output the flow increase injection signal. Specifically, in a steam generation system of a nuclear power system, the primary and secondary circuit systems are used for heat transfer. In the primary circuit, fluid flows within the primary circuit. Under normal circumstances, the primary circuit is a closed system, and the normal flow of radioactive gas occurs within the flow path within the primary circuit. At this time, monitoring the outside of the secondary circuit will not reveal a high concentration of radioactive gas, meaning the radioactive concentration will be very low. If a leak occurs in the primary circuit, radioactive gas within the primary circuit will leak out of the secondary circuit through the exchange device within the system. Radioactive gas will be generated outside the secondary circuit when monitoring the outside of the secondary circuit. The monitored radioactive gas activity outside the secondary circuit will increase. Therefore, when the radioactive gas activity outside the secondary circuit increases to a first preset value, a coolant leak in the primary circuit can be determined. Normally, when a coolant leak is detected in the primary circuit, the chemical and volumetric control system generates a flow increase signal to trigger the flow increase system in the primary circuit to increase flow to maintain the primary circuit's coolant flow rate. However, in this embodiment, when a steam leak is detected in the primary circuit, the chemical and volumetric control system blocks the flow increase signal, effectively shutting off the flow increase signal. Since the charging pump in the primary circuit does not receive the flow increase signal, it continues to output at its current flow rate, accelerating the rate at which the pressure in the primary circuit decreases. When the circuit pressure in the primary circuit decreases to a second preset value, a safety injection signal is generated. The chemical and volumetric control system, based on this safety injection signal, unlocks its previously blocked flow-increasing injection signal. Consequently, the chemical and volumetric control system triggers the output of the flow-increasing injection signal. Upon receiving this flow-increasing input signal, the charging pump increases the flow in the primary circuit, compensating for the circuit pressure in the primary circuit.

[0040] In one embodiment, the first preset value is greater than or equal to 1.0E 4 Bq / m 3That is, when the radioactivity is greater than the threshold value, the flow increase injection signal of the chemical and volume control system is triggered.

[0041] In one embodiment, the second preset value is greater than or equal to 11.5 MPa. That is, when the circuit pressure is less than the threshold value, the flow increase injection signal of the chemical and volume control system is triggered to unlock and lock.

[0042] In one embodiment, the control method for mitigating SGTR accidents in pressurized water reactor nuclear power plants of the present invention further includes: triggering the generation of a preset protection signal when the radioactivity level is greater than or equal to the first preset value, and triggering the flow increase injection signal of the chemical and volume control system to lock out the preset protection signal. The preset protection signal may be a "high activity concentration in the main steam system power plant radiation monitoring system" protection signal. This high activity concentration protection signal is a level FC1 signal. Radioactivity detectors are installed outside the main steam system pipeline to monitor radioactivity outside the secondary circuit, enabling online and continuous monitoring of the radioactivity level in the main steam pipeline. If a steam generator heat transfer tube is damaged, the detector accurately and quantitatively indicates the extent of the leak based on the detected activity level. When the detected activity level is sufficiently high, a "high activity concentration in the main steam system power plant radiation monitoring system" alarm signal may be triggered. The "Main Steam System Radiation Monitoring System Activity Concentration High" protection signal is a unique signal for SGTR accidents. New instrument control logic has been added to ensure that, when this signal is triggered, an SGTR accident has occurred and the upcharge flow rate remains unchanged until the safety injection signal is triggered. Safety injection signals include: Pressurizer Pressure Low 3 signal; Lead-Lag SG Pressure Low 2 signal; Hot Section ΔPsat Low 1 signal (B and C states, coolant pump in service); Hot Section RCP Loop Water Level Low 1 signal (C and D states, coolant pump out of service); and Containment Pressure High 2 signal. The safety injection signal triggers the commissioning of the chemical and volumetric control systems, replenishing the primary water charge to ensure core cooling and remove core decay heat. Therefore, to ensure the plant's water replenishment function is not affected, control logic for the safety injection signal has been added to unlock the lockout signal for item 1, ensuring that the upcharge function for high-pressure safety injection is not affected. After an SGTR accident occurs, the "Main Steam System Power Plant Radiation Monitoring System Activity Concentration High" protection signal is immediately triggered. Before the safety injection signal is triggered, the upcharge flow rate will not automatically increase as the pressurizer water level drops. The primary circuit water level will drop rapidly, and the primary circuit pressure will also drop rapidly, triggering the safety injection signal earlier. By limiting the increase in the upcharge flow rate, the present invention causes the primary circuit pressure to drop more quickly, triggering the safety injection signal earlier, reducing the breach integral flow rate at the breach, and thus mitigating the consequences of an SGTR accident.

[0043] Optionally, in one embodiment, the charging pump includes a unique charging pump; the primary circuit maintains normal operation through the unique charging pump; the chemical and volume control system is connected to the unique charging pump, and the unique charging pump is used to trigger flow increase according to the flow increase injection signal to increase the flow of the primary circuit. Specifically, in a certain second-generation reactor type, there is a charging pump in the nuclear power plant. Under normal operating conditions, the charging pump is used for charging. In the event of a primary circuit rupture loss of water accident and SGTR accident, the charging pump is used as a high-pressure injection pump. After the SGTR accident occurs, it increases the flow rate according to the flow increase injection signal of the chemical and volume control system to compensate for the flow of the primary circuit.

[0044] Optionally, in one embodiment, the charging pump includes a main charging pump and a backup charging pump; in the default state, the primary circuit maintains normal operation through the main charging pump; the chemical and volume control system is connected to the backup charging pump, and the backup charging pump is used to trigger the start-up according to the flow increase injection signal to increase the flow of the primary circuit. Specifically, in a certain third-generation advanced pressurized water reactor type, there are two charging pumps in the nuclear power plant, and under normal operating conditions, one charging pump (corresponding to the main charging pump) is in operation. After an SGTR accident occurs, a flow increase injection signal is generated by the chemical and volume control system to trigger the start-up of the second charging pump (corresponding to the backup charging pump), and the charging flow rate increases.

[0045] like Figure 2As shown, a control device 100 for mitigating SGTR accidents in pressurized water reactor nuclear power plants according to the present invention includes: a radioactivity monitoring unit 110 for monitoring the radioactivity outside the secondary circuit when the primary circuit is operating normally, wherein the primary circuit is maintained in normal operation by a charging pump; a locking unit 120 for locking the flow increase injection signal of the chemical and volume control system to shut off the output of the flow increase injection signal when the radioactivity is greater than or equal to a first preset value, wherein the chemical and volume control system is connected to the charging pump, and the charging pump is configured to trigger flow increase based on the flow increase injection signal; a pressure monitoring unit 130 for monitoring the circuit pressure of the primary circuit; and a locking unit 140 for triggering the generation of a safety injection signal when the circuit pressure is less than or equal to a second preset value, thereby unlocking the flow increase injection signal of the chemical and volume control system based on the safety injection signal, causing the chemical and volume control system to output the flow increase injection signal. Specifically, the radioactivity concentration outside the secondary circuit is monitored by the radioactivity monitoring unit 110. When a leak occurs in the primary circuit, radioactive material within the primary circuit leaks through the exchange device within the system to the outside of the secondary circuit. Radioactive gas is then monitored outside the secondary circuit, and the monitored radioactive gas activity outside the secondary circuit increases. Therefore, when the radioactive gas activity outside the secondary circuit increases to a first preset value, a coolant leak in the primary circuit can be determined. Normally, when a coolant leak is detected in the primary circuit, the chemical and volumetric control system generates a flow increase signal to trigger the flow increase system in the primary circuit to increase flow to maintain the steam flow pressure in the primary circuit. However, in this embodiment, when a steam leak is detected in the primary circuit, the locking unit 120 blocks the flow increase signal from the chemical and volumetric control system, causing it to shut off the flow increase signal. At this point, the charging pump in the primary circuit, not receiving the flow increase signal, continues to output at its current flow rate. The pressure monitoring unit 130 detects that the pressure in the primary circuit is decreasing at an accelerated rate. When the loop pressure in a circuit is reduced to a second preset value, the unlocking unit 140 triggers the generation of a safety injection signal, and unlocks the flow increase injection signal of the chemical and volume control system according to the safety injection signal. Therefore, the chemical and volume control system will trigger the output of the flow increase injection signal. When the charging pump receives the flow increase input signal, it increases the flow of the circuit and compensates for the loop pressure of the circuit. In one embodiment, the locking unit 120 is also used to trigger the generation of a preset protection signal when the radioactive activity is greater than or equal to the first preset value, and trigger the locking of the flow increase injection signal of the chemical and volume control system through the preset protection signal. That is, the locking action of the locking unit 120 is triggered by the "high activity concentration of the main steam system power plant radiation monitoring system" protection signal.

[0046] In addition, such as Figure 2The pressurized water reactor (PWR) of a nuclear power plant of the present invention includes a charging pump 230, a chemical and volume control system 240, a primary circuit 210, a secondary circuit 220, and the aforementioned PWR nuclear power plant SGTR accident control device 100. In the steam generation system of the nuclear power system, the primary and secondary circuits are used for heat transfer. In the primary circuit, coolant flows within the primary circuit. Under normal circumstances, the primary circuit is a closed system, and the normal flow of radioactive coolant occurs within the circulation path within the primary circuit. When monitoring the outside of the secondary circuit, there will not be a high concentration of radioactive gas, meaning the obtained radioactive concentration will be very low. When a leak occurs in the primary circuit, the radioactive coolant in the primary circuit will leak through the exchange device within the system to the outside of the secondary circuit. Radioactive gas will be generated when monitoring the outside of the secondary circuit. The activity of the radioactive gas monitored outside the secondary circuit will increase. Therefore, when the radioactive gas activity outside the secondary circuit increases to a first preset value, it can be determined that a coolant leak has occurred in the primary circuit. Under normal circumstances, when a coolant leak is detected in the primary circuit, the chemical and volumetric control system generates a flow increase injection signal, triggering the flow increase system in the primary circuit to increase flow to maintain the flow pressure in the primary circuit. However, in this embodiment, when a coolant leak is detected in the primary circuit, the chemical and volumetric control system blocks the flow increase injection signal, causing the chemical and volumetric control system to shut off the output of the flow increase injection signal. At this time, the charging pump in the primary circuit, not receiving the flow increase input signal, continues to output at the current flow rate, accelerating the rate of decrease in the circuit pressure in the primary circuit. When the circuit pressure in the primary circuit decreases to a second preset value, it triggers the generation of a safety injection signal. The chemical and volumetric control system, based on this safety injection signal, unlocks its previously blocked flow increase injection signal. Therefore, the chemical and volumetric control system triggers the output of the flow increase injection signal. Upon receiving the flow increase input signal, the charging pump increases flow in the primary circuit, compensating for the circuit pressure in the primary circuit.

[0047] Optionally, in the pressurized water reactor of the nuclear power plant of the present invention, the charging pump includes a unique charging pump, and the primary circuit maintains normal operation through the unique charging pump; the chemical and volume control system is connected to the unique charging pump, and the unique charging pump is used to trigger the flow increase according to the flow increase injection signal to increase the flow of the primary circuit. Specifically, in a certain second-generation reactor type, there is a charging pump in the nuclear power plant. Under normal operating conditions, the charging pump is used as a charging pump. In the event of a primary circuit rupture loss of water accident and SGTR accident, the charging pump is used as a high-pressure injection pump. After the SGTR accident occurs, it increases the flow rate according to the flow increase injection signal of the chemical and volume control system to compensate for the flow of the primary circuit.

[0048] Optionally, in the pressurized water reactor of a nuclear power plant of the present invention, the charging pump includes a main charging pump and a backup charging pump; in the default state, the primary circuit maintains normal operation through the main charging pump; the chemical and volume control system is connected to the backup charging pump, and the backup charging pump is used to trigger the start-up according to the flow increase injection signal to increase the flow of the primary circuit. Specifically, in a certain third-generation advanced pressurized water reactor type, there are two charging pumps in the nuclear power plant, and under normal operating conditions, one charging pump (corresponding to the main charging pump) is in operation. After an SGTR accident occurs, a flow increase injection signal is generated by the chemical and volume control system to trigger the start-up of the second charging pump (corresponding to the backup charging pump), and the charging flow rate increases.

[0049] It is understandable that the above embodiments only express the preferred implementation modes of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the patent scope of the present invention. It should be pointed out that for ordinary technicians in this field, without departing from the concept of the present invention, the above technical features can be freely combined, and several deformations and improvements can be made, all of which fall within the scope of protection of the present invention. Therefore, all equivalent changes and modifications made to the scope of the claims of the present invention should fall within the scope of coverage of the claims of the present invention.

Claims

1. A control method for mitigating SGTR accidents in pressurized water reactor nuclear power plants, characterized in that: The following steps are involved: S1. Monitoring the radioactive activity outside the secondary circuit when the primary circuit is operating normally, wherein the primary circuit is maintained in normal operation by a charging pump; S2. When the radioactivity is greater than or equal to a first preset value, blocking a flow increase injection signal of a chemical and volume control system to shut down output of the flow increase injection signal, wherein a charging pump of the chemical and volume control system is used to trigger flow increase according to the flow increase injection signal; S3. Monitoring the loop pressure of the first loop and triggering generation of a safety injection signal when the loop pressure is less than or equal to a second preset value, unlocking the flow-increasing injection signal of the chemical and volume control system according to the safety injection signal, so that the chemical and volume control system outputs the flow-increasing injection signal; The method further includes: triggering generation of a preset protection signal when the radioactivity is greater than or equal to the first preset value, and triggering a flow increase injection signal of a locking chemical and volume control system through the preset protection signal.

2. The control method for mitigating SGTR accidents in pressurized water reactor nuclear power plants according to claim 1, characterized in that: The first preset value is greater than or equal to 1.0E 4 Bq / m 3 .

3. The control method for mitigating SGTR accidents in pressurized water reactor nuclear power plants according to claim 1, characterized in that: The second preset value is less than or equal to 11.5 MPa.

4. The control method for mitigating SGTR accidents in pressurized water reactor nuclear power plants according to claim 1, characterized in that: The charging pump includes a single charging pump; The primary circuit maintains normal operation through the sole charging pump; The chemical and volume control system is connected to the only charging pump, and the only charging pump is used to trigger flow increase according to the flow increase injection signal to increase the flow of the primary circuit.

5. The control method for mitigating SGTR accidents in pressurized water reactor nuclear power plants according to claim 1, characterized in that: The charging pump includes a main charging pump and a backup charging pump; In the default state, the primary circuit maintains normal operation through the main charging pump; The chemical and volume control system is connected to the standby charging pump, and the standby charging pump is used to trigger and start according to the flow increase injection signal to increase the flow of the primary circuit.

6. A control device for mitigating SGTR accidents in pressurized water reactor nuclear power plants, characterized in that: include: a radioactive activity monitoring unit, configured to monitor the radioactive activity outside the secondary circuit when the primary circuit is operating normally, wherein the primary circuit is maintained in normal operation by a charging pump; a locking unit, configured to lock a flow increase injection signal of a chemical and volume control system when the radioactivity is greater than or equal to a first preset value, so as to shut off the output of the flow increase injection signal, wherein the chemical and volume control system is connected to the charging pump, and the charging pump is configured to trigger flow increase according to the flow increase injection signal; a pressure monitoring unit, configured to monitor the circuit pressure of the primary circuit; a locking unit, configured to trigger generation of a safety injection signal when the circuit pressure is less than or equal to a second preset value, so as to unlock the flow-increasing injection signal of the chemical and volume control system according to the safety injection signal, so that the chemical and volume control system outputs the flow-increasing injection signal; The locking unit is further configured to trigger generation of a preset protection signal when the radioactivity is greater than or equal to the first preset value, and trigger locking of a flow increase injection signal of the chemical and volume control system through the preset protection signal.

7. A pressurized water reactor for a nuclear power plant, characterized in that: It comprises a charging pump, a chemical and volume control system, a primary circuit and a secondary circuit, and the control device as claimed in claim 6.

8. The pressurized water reactor of a nuclear power plant according to claim 7, characterized in that: The charging pump includes a single charging pump, The primary circuit maintains normal operation through the sole charging pump; The chemical and volume control system is connected to the only charging pump, and the only charging pump is used to trigger flow increase according to the flow increase injection signal to increase the flow of the primary circuit.

9. The pressurized water reactor of a nuclear power plant according to claim 7, characterized in that: The charging pump includes a main charging pump and a backup charging pump; In the default state, the primary circuit maintains normal operation through the main charging pump; The chemical and volume control system is connected to the standby charging pump, and the standby charging pump is used to trigger and start according to the flow increase injection signal to increase the flow of the primary circuit.

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