A circulating system before sampling of a water tank in a containment vessel

Abstract

The application relates to a circulating system before sampling of a water tank in a containment vessel. In the system, the first end of a first PTR purification pump is connected with the first end of a first PTR inlet valve through a pipeline, and the second end of the first PTR inlet valve is connected with the first water outlet of the water tank in the containment vessel through a pipeline. The second end of the first PTR purification pump is connected with the water inlet of the water tank in the containment vessel through a pipeline; and the first circulating loop is formed by the water tank in the containment vessel, the first PTR purification pump, the first PTR inlet valve and the connecting pipeline. Before sampling of the water tank in the containment vessel, the first PTR purification pump and the first PTR inlet valve are opened, and the first circulating loop is operated for a first preset time. The application realizes the circulation before sampling of the water tank in the containment vessel by using the existing purification pump, greatly reduces the number of devices for the circulation before sampling, reduces the workload of the staff, reduces the power consumption and lowers the cost.

Description

Technical Field

[0001] This invention relates to the field of nuclear power plant operation monitoring, and more specifically, to a pre-sampling circulation system for refueling tanks within the containment. Background Technology

[0002] Before sampling, the IRWST (Intake Water Tank) inside the containment vessel of a nuclear power plant needs to be circulated, which means that the water in the IRWST tank is mixed evenly to make the sampling more accurate.

[0003] refer to Figure 1 This diagram illustrates the pre-sampling circulation method in existing nuclear power units (such as Hualong One). This scheme requires circulation via three sets of RIS system low-pressure safety injection pumps. After each RIS system low-pressure safety injection pump starts, it automatically drives all corresponding RRI / SEC system pumps to start. Ultimately, all three low-pressure safety injection pumps, five RRI pumps, and five SEC pumps will be running simultaneously. After seven hours of operation, the IRWST water tank is considered to be uniformly mixed. Throughout the process and before starting the circulation, several on-site operators must be dispatched to check the pump start-up process and confirm that there are no abnormalities. During the entire seven-hour circulation period, the main control operator must continuously monitor the operation of 13 pumps through the parameter monitoring screen in the main control room. Both the main control operator and the on-site operators bear a significant workload. Furthermore, the simultaneous start-up of 13 10kV high-power pumps puts pressure on the safe and reliable operation of the unit and is not conducive to the economical operation of the power plant. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a system for circulating water before sampling in the refueling tank inside the containment.

[0005] The technical solution adopted by the present invention to solve its technical problem is: to construct a pre-sampling circulation system for a refueling tank inside the containment, including a refueling tank inside the containment, a first PTR purification pump and a first PTR inlet valve;

[0006] The first end of the first PTR purification pump is connected to the first end of the first PTR inlet valve via a pipeline, and the second end of the first PTR inlet valve is connected to the first outlet of the refueling tank inside the containment via a pipeline; the second end of the first PTR purification pump is connected to the inlet of the refueling tank inside the containment via a pipeline; the refueling tank inside the containment, the first PTR purification pump, the first PTR inlet valve, and the connecting pipeline form a first circulation loop;

[0007] Before sampling the refueling tank inside the containment, the first PTR purification pump and the first PTR inlet valve are turned on, so that the first circulation loop runs for a first preset time.

[0008] Furthermore, the pre-sampling circulation system of the refueling tank inside the containment described in this invention also includes a first RCV charging pump, which is connected to the first circulation loop via a pipeline.

[0009] If the first RCV charging pump starts during the operation of the first circulation loop, then the first PTR purification pump and the first PTR inlet valve are closed.

[0010] Furthermore, the pre-sampling circulation system of the refueling tank inside the containment described in this invention also includes a first check valve, a first throttling orifice plate, at least one manual isolation valve, and at least one electric valve.

[0011] The second end of the first PTR purification pump is connected to the first end of the first check valve via a pipeline. The second end of the first check valve is connected to the first end of the first orifice plate via a pipeline. The second end of the first orifice plate is connected to the inlet of the refill water tank inside the containment via a pipeline. The at least one manual isolation valve and the at least one electric valve are installed in the first circulation loop.

[0012] Furthermore, the pre-sampling circulation system of the refueling tank inside the containment described in this invention also includes a second PTR purification pump and a second PTR inlet valve.

[0013] The first end of the second PTR purification pump is connected to the first end of the second PTR inlet valve via a pipeline, and the second end of the second PTR inlet valve is connected to the second outlet of the refueling tank inside the containment via a pipeline; the second end of the second PTR purification pump is connected to the inlet of the refueling tank inside the containment via a pipeline; the refueling tank inside the containment, the second PTR purification pump, the second PTR inlet valve, and the connecting pipeline form a second circulation loop;

[0014] Before sampling the refueling tank inside the containment, the second PTR purification pump and the second PTR inlet valve are turned on, so that the second circulation loop runs for a second preset time.

[0015] Furthermore, in the pre-sampling circulation system of the refueling tank inside the containment described in this invention, before sampling the refueling tank inside the containment, the first circulation loop is first activated. If the first circulation loop malfunctions within the first preset time, the first circulation loop is closed and the second circulation loop is activated.

[0016] Furthermore, in the pre-sampling circulation system of the refueling tank inside the containment described in this invention, before sampling the refueling tank inside the containment, the second circulation loop is first activated. If the second circulation loop malfunctions within the second preset time, the second circulation loop is closed and the first circulation loop is activated.

[0017] Furthermore, in the pre-sampling circulation system of the refueling tank inside the containment described in this invention, before sampling the refueling tank inside the containment, the first circulation loop and the second circulation loop are activated simultaneously, so that the first circulation loop and the second circulation loop run for a third preset time.

[0018] Furthermore, the pre-sampling circulation system of the refueling tank inside the containment described in this invention also includes a second RCV charging pump, which is connected to the second circulation loop via a pipeline.

[0019] If the second RCV charging pump starts during the operation of the second circulation loop, then the second PTR purification pump and the second PTR inlet valve are closed.

[0020] Furthermore, the pre-sampling circulation system of the refueling tank inside the containment described in this invention also includes a second check valve, a second throttling orifice plate, at least one manual isolation valve, and at least one electric valve.

[0021] The second end of the second PTR purification pump is connected to the first end of the second check valve through a pipeline. The second end of the second check valve is connected to the first end of the second orifice plate through a pipeline. The second end of the second orifice plate is connected to the inlet of the refill water tank inside the containment through a pipeline. The at least one manual isolation valve and the at least one electric valve are installed in the second circulation loop.

[0022] Furthermore, in the pre-sampling circulation system of the refueling tank inside the containment as described in this invention, the second circulation loop is connected to the PTR depletion tank makeup water via a pipeline.

[0023] The pre-sampling circulation system for the refueling tank inside the containment according to the present invention has the following beneficial effects: The present invention utilizes existing purification pumps to realize pre-sampling circulation of the refueling tank inside the containment, which greatly reduces the number of devices required for pre-sampling circulation, thereby reducing the workload of staff, reducing power consumption, and lowering costs. Attached Figure Description

[0024] The present invention will be further described below with reference to the accompanying drawings and embodiments. In the accompanying drawings:

[0025] Figure 1 This is a schematic diagram of the circulation method before sampling in the refueling tank inside the containment in the existing technology;

[0026] Figure 2 This is a schematic diagram of the pre-sampling circulation system of the refueling tank inside the containment provided in an embodiment of the present invention. Detailed Implementation

[0027] To provide a clearer understanding of the technical features, objectives, and effects of the present invention, specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0028] In a preferred embodiment, reference Figure 2 The pre-sampling circulation system of the in-containment refueling tank in this embodiment includes an in-containment refueling tank (IRWST), a first PTR purification pump 101, and a first PTR inlet valve 102. The first end of the first PTR purification pump 101 is connected to the first end of the first PTR inlet valve 102 via a pipe, and the second end of the first PTR inlet valve 102 is connected to the first outlet of the in-containment refueling tank via a pipe. The second end of the first PTR purification pump 101 is connected to the inlet of the in-containment refueling tank via a pipe. The in-containment refueling tank, the first PTR purification pump 101, the first PTR inlet valve 102, and the connecting pipes form a first circulation loop 10.

[0029] Before sampling the refueling tank inside the containment, the first PTR purification pump 101 and the first PTR inlet valve 102 are opened. If other valves in the first circulation loop 10 are closed, they are opened simultaneously to maintain smooth flow in the first circulation loop 10, allowing it to run for a first preset time. According to the requirement for circulation before sampling, at least one volume of turbidity must be achieved. This requires the first circulation loop 10 to achieve at least one volume of turbidity after running for the first preset time. In other words, the first preset time needs to be determined based on the amount of turbidity (at least one volume) and the flow rate of the first PTR purification pump 101. For example, the first PTR purification pump used in the Hualong One nuclear power plant design is PTR4440PO, with a rated flow rate of 90 m³ / h. 3 / h, a 22h cycle is required to meet the requirement of at least one volume.

[0030] It should also be noted that, considering there is no cooler on the first circulation loop 10, the temperature of the refueling water tank IRWST inside the containment may rise during the circulation process. Therefore, this embodiment monitors the temperature of the first circulation loop 10 throughout the first preset time. Multiple test results show that after the first circulation loop 10 has circulated for the first preset time, the temperature of the refueling water tank IRWST inside the containment only rises by 0.3℃, and the temperature of the refueling water tank IRWST inside the containment will subsequently slowly decrease to match the ambient temperature, fully meeting the actual engineering safety requirements.

[0031] This embodiment utilizes existing purification pumps to circulate the water tank inside the containment before sampling, greatly reducing the number of devices required for pre-sampling circulation, thereby reducing the workload of staff, reducing power consumption, and lowering costs.

[0032] In some embodiments, the system is referenced in the pre-sampling circulation system of the refueling tank within the containment. Figure 2 The pre-sampling circulation system of the refueling tank inside the containment in this embodiment also includes a first RCV charging pump 301. The first RCV charging pump 301 is connected to the first circulation loop 10 through a pipeline, specifically connected to the pipeline between the first PTR inlet valve 102 and the first outlet of the refueling tank inside the containment.

[0033] Before sampling the refueling tank inside the containment, the first PTR purification pump 101 and the first PTR inlet valve 102 are opened. If other valves in the first circulation loop 10 are closed, they are opened simultaneously to maintain smooth flow in the first circulation loop 10, allowing it to run for a first preset time. If the first RCV charging pump 301 starts within the first preset time of the first circulation loop 10, it will draw water from the refueling tank IRWST inside the containment. Given that the priority (safety level) of the first RCV charging pump 301 is higher than the circulation before sampling the refueling tank inside the containment, the first PTR purification pump 101 and the first PTR inlet valve 102 are closed at this time. Furthermore, if the first RCV charging pump 301 finishes operating, the first circulation loop 10 can be reopened.

[0034] In this embodiment, considering that the safety level of the RCV charging pump is higher than that of the pre-sampling circulation of the refueling tank inside the containment, the pre-sampling circulation of the refueling tank inside the containment is suspended after the RCV charging pump is detected to start, so as to ensure the safety of the nuclear power plant.

[0035] In some embodiments, the system is referenced in the pre-sampling circulation system of the refueling tank within the containment. Figure 2 The pre-sampling circulation system of the refueling tank inside the containment in this embodiment also includes a first check valve 103, a first orifice plate 104, at least one manual isolation valve 40, and at least one electric valve 50. The second end of the first PTR purification pump 101 is connected to the first end of the first check valve 103 via a pipeline. The second end of the first check valve 103 is connected to the first end of the first orifice plate 104 via a pipeline. The second end of the first orifice plate 104 is connected to the inlet of the refueling tank inside the containment via a pipeline. The first check valve 103 is used to prevent backflow in the first circulation loop 10, and the first orifice plate 104 is used to control the flow rate of the first circulation loop 10. At least one manual isolation valve 40 and at least one electric valve 50 are installed in the first circulation loop 10. It can be understood that the manual isolation valve 40 and the electric valve 50 can be installed as needed, for example, according to... Figure 2 The device is installed in the position shown and is required to remain open after the first circulation loop 10 is opened. This embodiment utilizes a check valve and a throttling orifice plate in the first circulation loop to ensure more stable operation of the first circulation loop.

[0036] In some embodiments, the system is referenced in the pre-sampling circulation system of the refueling tank within the containment. Figure 2 The pre-sampling circulation system of the refueling tank inside the containment in this embodiment also includes a second PTR purification pump 201 and a second PTR inlet valve 202. The first end of the second PTR purification pump 201 is connected to the first end of the second PTR inlet valve 202 via a pipe, and the second end of the second PTR inlet valve 202 is connected to the second outlet of the refueling tank inside the containment via a pipe. The second end of the second PTR purification pump 201 is connected to the inlet of the refueling tank inside the containment via a pipe. The refueling tank inside the containment, the second PTR purification pump 201, the second PTR inlet valve 202, and the connecting pipes form a second circulation loop 20.

[0037] Before sampling the refueling tank inside the containment, open the second PTR purification pump 201 and the second PTR inlet valve 202. If other valves in the second circulation loop 20 are closed, open other valves in the second circulation loop 20 at the same time to keep the second circulation loop 20 flowing smoothly and to make the second circulation loop 20 run for a second preset time.

[0038] According to the requirement for pre-sampling circulation, at least one volume of turbidity must be achieved. This necessitates that the second circulation loop 20 achieves at least one volume of turbidity after running for a second preset time. In other words, the second preset time must be determined based on the required turbidity of at least one volume and the flow rate of the second PTR purification pump 201. For example, the second PTR purification pump used in the Hualong One nuclear power plant design is the PTR4430PO, with a rated flow rate of 90 m³ / h. 3 / h, a 22h cycle is required to meet the requirement of at least one volume.

[0039] It should also be noted that, considering the lack of a cooler in the second circulation loop 20, the temperature of the refueling water tank IRWST inside the containment may rise during the circulation process. Therefore, this embodiment monitors the temperature of the second circulation loop 20 throughout the second preset time. Multiple test results show that after the second circulation loop 20 has circulated for the second preset time, the temperature of the refueling water tank IRWST inside the containment only increases by 0.3℃, and the temperature of the refueling water tank IRWST inside the containment subsequently slowly decreases to match the ambient temperature, fully meeting the actual engineering safety requirements.

[0040] This embodiment utilizes existing purification pumps to circulate the water tank inside the containment before sampling, greatly reducing the number of devices required for pre-sampling circulation, thereby reducing the workload of staff, reducing power consumption, and lowering costs.

[0041] In some embodiments, the system is referenced in the pre-sampling circulation system of the refueling tank within the containment. Figure 2The pre-sampling circulation system for the refueling tank inside the containment in this embodiment includes a first circulation loop 10 and a second circulation loop 20, both of which can independently complete the pre-sampling circulation. Before sampling the refueling tank inside the containment, the first circulation loop 10 is activated. If the first circulation loop 10 malfunctions within a first preset time, it is shut down and the second circulation loop 20 is activated. It is understood that the running time of the second circulation loop 20 needs to cover the circulation already completed by the first circulation loop 10. This embodiment provides two independent circulation loops, providing a backup to ensure that the pre-sampling circulation can be completed smoothly.

[0042] In some embodiments, the system is referenced in the pre-sampling circulation system of the refueling tank within the containment. Figure 2 The pre-sampling circulation system for the refueling tank inside the containment in this embodiment includes a first circulation loop 10 and a second circulation loop 20, both of which can independently complete the pre-sampling circulation. Before sampling the refueling tank inside the containment, the second circulation loop 20 is activated first. If the second circulation loop 20 malfunctions within a second preset time, it is shut down and the first circulation loop 10 is activated. It can be understood that the running time of the first circulation loop 10 needs to cover the circulation already completed by the second circulation loop 20. This embodiment provides two independent circulation loops, providing a backup to ensure that the pre-sampling circulation can be successfully completed.

[0043] In some embodiments, the system is referenced in the pre-sampling circulation system of the refueling tank within the containment. Figure 2 The pre-sampling circulation system of the refueling tank inside the containment in this embodiment includes a first circulation loop 10 and a second circulation loop 20, and both the first circulation loop 10 and the second circulation loop 20 can independently complete the pre-sampling circulation. Before sampling the refueling tank inside the containment, the first circulation loop 10 and the second circulation loop 20 are simultaneously activated, causing the first circulation loop 10 and the second circulation loop 20 to run for a third preset time. It can be understood that because the flow rate after the first circulation loop 10 and the second circulation loop 20 are activated simultaneously is greater than that after only the first circulation loop 10 or the second circulation loop 20 is activated, the third preset time is shorter than the first preset time and the second preset time. In this embodiment, activating both circulation loops simultaneously can accelerate the agitation, thereby shortening the agitation time.

[0044] In some embodiments, the system is referenced in the pre-sampling circulation system of the refueling tank within the containment. Figure 2 The pre-sampling circulation system of the refueling tank inside the containment in this embodiment also includes a second RCV charging pump 302. The second RCV charging pump 302 is connected to the second circulation loop 20 through a pipeline, specifically connected to the pipeline between the second PTR inlet valve 202 and the second outlet of the refueling tank inside the containment.

[0045] Before sampling the refueling tank inside the containment, the second PTR purification pump 201 and the second PTR inlet valve 202 are opened. If other valves in the second circulation loop 20 are closed, they are simultaneously opened to maintain smooth flow in the second circulation loop 20, allowing it to run for a second preset time. If the second RCV charging pump 302 starts within the second preset time of the second circulation loop 20, it will draw water from the refueling tank IRWST inside the containment. Given that the priority (safety level) of the second RCV charging pump 302 is higher than the circulation before sampling the refueling tank inside the containment, the second PTR purification pump 201 and the second PTR inlet valve 202 are closed at this time. Furthermore, if the second RCV charging pump 302 finishes operating, the second circulation loop 20 can be reopened.

[0046] In this embodiment, considering that the safety level of the RCV charging pump is higher than that of the pre-sampling circulation of the refueling tank inside the containment, the pre-sampling circulation of the refueling tank inside the containment is suspended after the RCV charging pump is detected to start, so as to ensure the safety of the nuclear power plant.

[0047] In some embodiments, the system is referenced in the pre-sampling circulation system of the refueling tank within the containment. Figure 2 The pre-sampling circulation system of the refueling tank inside the containment in this embodiment also includes a second check valve 203, a second orifice plate 204, at least one manual isolation valve 40, and at least one electric valve 50. The second end of the second PTR purification pump 201 is connected to the first end of the second check valve 203 via a pipeline. The second end of the second check valve 203 is connected to the first end of the second orifice plate 204 via a pipeline. The second end of the second orifice plate 204 is connected to the inlet of the refueling tank inside the containment via a pipeline. At least one manual isolation valve 40 and at least one electric valve 50 are installed in the second circulation loop 20. It can be understood that the manual isolation valve 40 and the electric valve 50 can be installed as needed, for example, according to... Figure 2 The device is installed in the position shown and is required to remain open after the second circulation loop 20 is opened. This embodiment utilizes a check valve and a throttling orifice plate in the second circulation loop to ensure more stable operation of the second circulation loop.

[0048] In some embodiments, the second circulation loop 20 is connected via piping to the PTR (Reactor Pool and Fuel Pool Cooling and Treatment System) makeup water before sampling in the containment refueling tank. Alternatively, the second circulation loop 20 is connected via piping to the makeup water of two separate PTR makeup water tanks.

[0049] In summary, the pre-sampling circulation system of the containment refueling tank of the present invention has the following advantages:

[0050] 1. Avoiding the simultaneous start-up of all 13 large 10KV pumps in the RRI / SEC / RIS system (safety injection system) is beneficial to the safe operation of the power plant;

[0051] 2. It is conducive to the long-term reliable operation of nuclear safety systems RRI / SEC / RIS;

[0052] 3. Save on power plant operating costs. For electricity alone, after using the pre-sampling circulation system of the containment refueling water tank of this invention, each Hualong One unit will save more than 200,000 yuan in electricity costs per year.

[0053] 4. It greatly reduces the workload of the main control operator and on-site personnel during the circulation of the IRWST water tank in the containment (the optimized solution only requires monitoring the operation of one pump throughout the entire process).

[0054] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0055] Those skilled in the art will further recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both. To clearly illustrate the interchangeability of hardware and software, the components and steps of the various examples have been generally described in terms of functionality in the foregoing description. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of this invention.

[0056] The steps of the methods or algorithms described in conjunction with the embodiments disclosed herein can be implemented directly by hardware, a software module executed by a processor, or a combination of both. The software module can be located in random access memory (RAM), main memory, read-only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, hard disk, removable disk, CD-ROM, or any other form of storage medium known in the art.

[0057] The above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They do not limit the scope of protection of the present invention. All equivalent changes and modifications made within the scope of the claims of the present invention should fall within the scope of the claims of the present invention.

Claims

1. A pre-sampling circulation system for a refueling water tank inside a containment vessel, characterized in that, Includes an in-containment refueling tank, a first PTR purification pump (101), and a first PTR inlet valve (102); The first end of the first PTR purification pump (101) is connected to the first end of the first PTR inlet valve (102) through a pipeline, and the second end of the first PTR inlet valve (102) is connected to the first outlet of the refueling tank inside the containment through a pipeline; the second end of the first PTR purification pump (101) is connected to the inlet of the refueling tank inside the containment through a pipeline; the refueling tank inside the containment, the first PTR purification pump (101), the first PTR inlet valve (102) and the connecting pipeline form a first circulation loop (10); Before sampling the refueling tank inside the containment, the first PTR purification pump (101) and the first PTR inlet valve (102) are turned on, so that the first circulation loop (10) runs for a first preset time. It also includes a first check valve (103), a first orifice plate (104), at least one manual isolation valve (40) and at least one electric valve (50). The second end of the first PTR purification pump (101) is connected to the first end of the first check valve (103) through a pipeline. The second end of the first check valve (103) is connected to the first end of the first orifice plate (104) through a pipeline. The second end of the first orifice plate (104) is connected to the inlet of the refill water tank inside the containment through a pipeline. The at least one manual isolation valve (40) and the at least one electric valve (50) are installed in the first circulation loop (10).

2. The pre-sampling circulation system for the refueling tank inside the containment vessel according to claim 1, characterized in that, It also includes a first RCV charging pump (301), which is connected to the first circulation loop (10) via a pipeline. If the first RCV charging pump (301) is started during the operation of the first circulation loop (10), then the first PTR purification pump (101) and the first PTR inlet valve (102) are closed.

3. The pre-sampling circulation system for the refueling tank inside the containment vessel according to claim 1, characterized in that, It also includes a second PTR purification pump (201) and a second PTR inlet valve (202); The first end of the second PTR purification pump (201) is connected to the first end of the second PTR inlet valve (202) through a pipeline, and the second end of the second PTR inlet valve (202) is connected to the second outlet of the refueling tank inside the containment through a pipeline; the second end of the second PTR purification pump (201) is connected to the inlet of the refueling tank inside the containment through a pipeline; the refueling tank inside the containment, the second PTR purification pump (201), the second PTR inlet valve (202) and the connecting pipeline form a second circulation loop (20); Before sampling the refueling tank inside the containment, the second PTR purification pump (201) and the second PTR inlet valve (202) are turned on, so that the second circulation loop (20) runs for a second preset time.

4. The pre-sampling circulation system for the refueling tank inside the containment vessel according to claim 3, characterized in that, Before sampling the refueling tank inside the containment, the first circulation loop (10) is activated. If the first circulation loop (10) malfunctions within the first preset time, the first circulation loop (10) is closed and the second circulation loop (20) is activated.

5. The pre-sampling circulation system for the refueling tank inside the containment vessel according to claim 3, characterized in that, Before sampling the refueling tank inside the containment, the second circulation loop (20) is first activated. If the second circulation loop (20) malfunctions within the second preset time, the second circulation loop (20) is closed and the first circulation loop (10) is activated.

6. The pre-sampling circulation system for the refueling tank inside the containment vessel according to claim 3, characterized in that, Before sampling the refueling tank inside the containment, the first circulation loop (10) and the second circulation loop (20) are simultaneously activated, so that the first circulation loop (10) and the second circulation loop (20) run for a third preset time.

7. The pre-sampling circulation system for the refueling tank inside the containment as described in claim 3, characterized in that, It also includes a second RCV charging pump (302), which is connected to the second circulation loop (20) via a pipe. If the second RCV charging pump (302) is started during the operation of the second circulation loop (20), then the second PTR purification pump (201) and the second PTR inlet valve (202) are closed.

8. The pre-sampling circulation system for the refueling tank inside the containment vessel according to claim 3, characterized in that, It also includes a second check valve (203), a second orifice plate (204), at least one manually operated isolation valve (40) and at least one electrically operated valve (50). The second end of the second PTR purification pump (201) is connected to the first end of the second check valve (203) through a pipeline. The second end of the second check valve (203) is connected to the first end of the second orifice plate (204) through a pipeline. The second end of the second orifice plate (204) is connected to the inlet of the refill water tank inside the containment through a pipeline. The at least one manual isolation valve (40) and the at least one electric valve (50) are installed in the second circulation loop (20).

9. The pre-sampling circulation system for the refueling tank inside the containment according to claim 3, characterized in that, The second circulation loop (20) is connected to the PTR depletion tank for water replenishment via a pipeline.

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