Emergency cooling system for in-reactor fuel irradiation test loop

Abstract

The invention provides an emergency cooling system for an in-pile fuel irradiation test loop, and the system comprises a high-pressure safety injection part which communicates with a first water supply system and the in-pile fuel irradiation test loop, and comprises a first high-pressure safety injection branch part and a second high-pressure safety injection branch part; the low-pressure safety injection part is connected with the high-pressure safety injection part in parallel and is communicated with the second water supply system and the in-reactor fuel irradiation test loop, and the low-pressure safety injection part comprises a first low-pressure safety injection branch part and a second low-pressure safety injection branch part; the first low-pressure safety injection branch part comprises a plurality of first low-pressure safety injection boxes connected in parallel and first safety injection pumps connected with the first low-pressure safety injection boxes respectively, and the second low-pressure safety injection branch part comprises a plurality of second low-pressure safety injection boxes connected in parallel and second safety injection pumps connected with the second low-pressure safety injection boxes respectively. According to the technical scheme, the storage amount of safety injection cooling liquid is increased so as to ensure that a fuel element is cooled for a long time, and the overall reliability of the system is improved by adding a plurality of standby valves.

Description

[Technical field]

[0001] The present application relates to the field of nuclear fuel safety technology, and in particular to an emergency cooling system for an in-core fuel irradiation test loop. [Background technology]

[0002] According to national nuclear safety requirements, newly developed fuel assemblies must be irradiated in the reactor to simulate real operating conditions, and only after verifying the feasibility of the fuel assembly design, structural stability, and reliability of the manufacturing and assembly process can they be used in engineering. Therefore, new fuel assemblies must be irradiated in a reactor loop that can simulate their real operating conditions.

[0003] In order to prevent the high-temperature burning of fuel caused by the accident of water loss in the circuit, an emergency cooling system can be used as a safety measure. Generally, the emergency cooling system consists of three parts: high-pressure injection system, medium-pressure injection system, and low-pressure injection system. The system is complex and has a high failure rate, which is likely to affect the immediate demand for cooling function, and the investment cost is high and the economic applicability is insufficient.

[0004] Therefore, how to provide a light-structure emergency cooling system for nuclear fuel assemblies that is both low-cost and highly practical has become a technical problem that needs to be solved urgently. [Summary of the invention]

[0005] The embodiment of the present application provides an emergency cooling system for an in-pile fuel irradiation test circuit, aiming to solve the technical problems of high cost and complex system of emergency cooling system in related technologies.

[0006] The embodiment of the present application provides an emergency cooling system for a fuel irradiation test loop in a reactor, comprising:

[0007] The high-pressure injection unit connects the first water supply system with the in-pile fuel irradiation test circuit.

[0008] The high-pressure injection section includes a first high-pressure injection branch section and a second high-pressure injection branch section.

[0009] The first high-pressure safety injection branch comprises a first high-pressure safety injection tank, the first end, the second end and the third end of the first high-pressure safety injection tank are respectively connected to the first water supply system, the inlet main pipeline of the in-core fuel irradiation test circuit and the first high-pressure gas source; the second high-pressure safety injection branch comprises a second high-pressure safety injection tank, the first end, the second end and the third end of the second high-pressure safety injection tank are respectively connected to the first water supply system, the outlet main pipeline of the in-core fuel irradiation test circuit and the second high-pressure gas source,

[0010] The first high-pressure gas source drives the cooling liquid in the first high-pressure injection tank to the in-core fuel irradiation test circuit through the inlet main pipeline by gas expansion, and the second high-pressure gas source drives the cooling liquid in the second high-pressure injection tank to the in-core fuel irradiation test circuit through the outlet main pipeline by gas expansion;

[0011] The low-pressure injection unit is connected in parallel with the high-pressure injection unit, and is connected to the second water supply system and the in-pile fuel irradiation test circuit.

[0012] Wherein, the low-pressure injection part includes a first low-pressure injection branch part and a second low-pressure injection branch part.

[0013] The first low-pressure injection branch includes a plurality of first low-pressure injection tanks connected in parallel and a first injection pump connected to each of the plurality of first low-pressure injection tanks, the first end and the second end of each of the first low-pressure injection tanks are respectively connected to the second water supply system and the first end of the first injection pump, and the second end of the first injection pump is connected to the inlet main pipeline. The second low-pressure injection branch includes a plurality of second low-pressure injection tanks connected in parallel and a second injection pump connected to each of the plurality of second low-pressure injection tanks, the first end and the second end of each of the second low-pressure injection tanks are respectively connected to the second water supply system and the first end of the second injection pump, and the second end of the second injection pump is connected to the outlet main pipeline.

[0014] When the first injection pump is working, the cooling liquid in the corresponding first low-pressure injection tank is driven through the inlet main pipeline to the in-pile fuel irradiation test circuit. When the second injection pump is working, the cooling liquid in the corresponding second low-pressure injection tank is driven through the outlet main pipeline to the in-pile fuel irradiation test circuit.

[0015] In one embodiment of the present application, optionally, the high-pressure injection unit further includes:

[0016] A first manual stop valve and a first water supply solenoid valve are arranged in series in the passage between the first water supply system and the first high-pressure injection tank;

[0017] A second manual stop valve and a second water supply solenoid valve are arranged in series in the passage between the first water supply system and the second high-pressure injection tank;

[0018] The low-pressure injection unit also includes:

[0019] A third water supply solenoid valve is provided in the passage between the second water supply system and each of the first low-pressure injection tanks;

[0020] The fourth water supply solenoid valve is arranged in the passage between the second water supply system and each of the second low-pressure injection tanks.

[0021] In one embodiment of the present application, optionally, the high-pressure injection unit further includes:

[0022] A first liquid level monitoring device is arranged at the first high-pressure injection tank and connected to the first water supply solenoid valve;

[0023] The second liquid level monitoring device is arranged at the second high-pressure injection tank and connected to the second water supply solenoid valve.

[0024] In one embodiment of the present application, optionally, the high-pressure injection unit further includes:

[0025] A first pressure reducing valve and a first gas cylinder solenoid valve are arranged in series between the first high-pressure gas source and the first high-pressure injection box, wherein the first high-pressure gas source includes a plurality of high-pressure gas cylinders connected in parallel;

[0026] A second pressure reducing valve and a second gas cylinder solenoid valve are arranged in series between the second high-pressure gas source and the second high-pressure injection box, wherein the second high-pressure gas source includes a plurality of high-pressure gas cylinders connected in parallel;

[0027] A first overpressure exhaust pipe and a second overpressure exhaust pipe are respectively connected to the first high-pressure injection tank and the second high-pressure injection tank;

[0028] A first isolation valve and a first safety valve are arranged in series in the passage between the first high-pressure injection tank and the first overpressure exhaust pipe;

[0029] The second isolation valve and the second safety valve are arranged in series in the passage between the second high-pressure injection tank and the second overpressure exhaust pipe.

[0030] In one embodiment of the present application, optionally, the high-pressure injection unit further includes:

[0031] A first pressure monitoring device is arranged at the first high-pressure injection box and connected to the first gas cylinder solenoid valve;

[0032] The second pressure monitoring device is arranged at the second high-pressure injection box and connected to the second gas cylinder solenoid valve.

[0033] In one embodiment of the present application, optionally, a low-pressure stop valve is provided between each of the first low-pressure injection tanks and the corresponding first injection pump, and between each of the second low-pressure injection tanks and the corresponding second injection pump.

[0034] In one embodiment of the present application, optionally, each of the first high-pressure safety injection tank, the second high-pressure safety injection tank, the first low-pressure safety injection tank and the second low-pressure safety injection tank has a first isolation unit, a second isolation unit and a third isolation unit arranged in series on a water supply passage connected to the in-core fuel irradiation test circuit, wherein:

[0035] The first isolation unit includes a plurality of electric stop valves arranged in parallel;

[0036] The second isolation unit includes a plurality of isolation solenoid valves arranged in parallel;

[0037] The third isolation unit includes at least one total check valve;

[0038] A third pressure monitoring device is provided between the first isolation unit and the second isolation unit.

[0039] In one embodiment of the present application, optionally, the second end of the first injection pump is connected to the corresponding first isolation unit via a first low-pressure check valve;

[0040] The second end of the second injection pump is connected to the corresponding first isolation unit via a second low-pressure check valve.

[0041] In one embodiment of the present application, optionally, the low-pressure injection unit further includes:

[0042] The third low-pressure check valve is arranged on each of the first low-pressure safety injection tanks and each of the second low-pressure safety injection tanks.

[0043] The above technical scheme, in view of the technical problems in the related technologies of high cost and complex system of emergency cooling system, can simplify the configuration of the emergency cooling system, reduce the driving cost and the occupation of limited space resources in the reactor sealing building, increase the storage capacity of the injection cooling liquid to ensure that the fuel elements are cooled for a long time, and add multiple backup valves to improve the overall reliability of the system.

Brief Description of the Drawings

[0044] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0045] Figure 1 A schematic structural diagram of an emergency cooling system for an in-pile fuel irradiation test loop according to an embodiment of the present application is shown. [Specific implementation method]

[0046] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0047] Figure 1 A schematic structural diagram of an emergency cooling system for an in-pile fuel irradiation test loop according to an embodiment of the present application is shown.

[0048] like Figure 1 As shown, according to an embodiment of the present application, the emergency cooling system for the in-pile fuel irradiation test circuit includes a high-pressure safety injection part and a low-pressure safety injection part. The high-pressure safety injection part connects the first water supply system with the in-pile fuel irradiation test circuit, and the low-pressure safety injection part is connected in parallel with the high-pressure safety injection part, connecting the second water supply system with the in-pile fuel irradiation test circuit.

[0049] The high-pressure injection portion includes a first high-pressure injection branch portion and a second high-pressure injection branch portion.

[0050] The first high-pressure injection branch includes a first high-pressure injection tank 101, the first end, the second end and the third end of the first high-pressure injection tank 101 are respectively connected to the first water supply system, the inlet main pipeline 001 of the in-core fuel irradiation test circuit and the first high-pressure gas source.

[0051] In a possible design, the high-pressure injection unit further includes a first manual stop valve 110 and a first water supply solenoid valve 111 , which are arranged in series in the passage between the first water supply system and the first high-pressure injection tank 101 .

[0052] The second high-pressure injection branch includes a second high-pressure injection tank 201, the first end, the second end and the third end of the second high-pressure injection tank 201 are respectively connected to the first water supply system, the outlet main pipeline 002 of the in-core fuel irradiation test circuit and the second high-pressure gas source.

[0053] In a possible design, the high-pressure injection unit further includes a second manual stop valve 210 and a second water supply solenoid valve 211 , which are arranged in series in the passage between the first water supply system and the second high-pressure injection tank 201 .

[0054] In one possible design, the high-pressure injection part also includes: a first pressure reducing valve 107 and a first gas cylinder solenoid valve 116, a second pressure reducing valve 207 and a second gas cylinder solenoid valve 216, a first overpressure exhaust pipeline and a second overpressure exhaust pipeline, a first isolation valve 108 and a first safety valve 109, a second isolation valve 208 and a second safety valve 209.

[0055] The first pressure reducing valve 107 and the first gas cylinder solenoid valve 116 are arranged in series between the first high-pressure gas source and the first high-pressure injection box 101. The first high-pressure gas source includes a plurality of high-pressure gas cylinders connected in parallel. Figure 1 As shown, the first high-pressure gas source includes two high-pressure gas cylinders 105 and 106 connected in parallel. Of course, the number of high-pressure gas cylinders can be any number set according to the emergency cooling demand, and is not limited to the two shown in the figure.

[0056] The second pressure reducing valve 207 and the second gas cylinder solenoid valve 216 are arranged in series between the second high pressure gas source and the second high pressure injection box 201. The second high pressure gas source includes a plurality of high pressure gas cylinders connected in parallel. Figure 1 As shown, the second high-pressure gas source includes two high-pressure gas cylinders 205 and 206 connected in parallel. Of course, the number of high-pressure gas cylinders can be any number set according to the emergency cooling demand, and is not limited to the two shown in the figure.

[0057] The first overpressure exhaust pipeline and the second overpressure exhaust pipeline are respectively connected to the first high-pressure injection tank 101 and the second high-pressure injection tank 201. The first isolation valve 108 and the first safety valve 109 are arranged in series in the passage between the first high-pressure injection tank 101 and the first overpressure exhaust pipeline. The second isolation valve 208 and the second safety valve 209 are arranged in series in the passage between the second high-pressure injection tank 201 and the second overpressure exhaust pipeline.

[0058] In a possible design, the high pressure injection unit further includes a first pressure monitoring device 112 and a second pressure monitoring device 212. The first pressure monitoring device 112 is disposed at the first high pressure injection tank 101 and connected to the first gas cylinder solenoid valve 116; the second pressure monitoring device 212 is disposed at the second high pressure injection tank 201 and connected to the second gas cylinder solenoid valve 216.

[0059] In a possible design, the high pressure injection unit further includes a first liquid level monitoring device 113 and a second liquid level monitoring device 213. The first liquid level monitoring device 113 is disposed at the first high pressure injection tank 101 and connected to the first water supply solenoid valve 111; the second liquid level monitoring device 213 is disposed at the second high pressure injection tank 201 and connected to the second water supply solenoid valve 211.

[0060] The low-pressure injection portion includes a first low-pressure injection branch portion and a second low-pressure injection branch portion.

[0061] The first low-pressure injection branch includes a plurality of first low-pressure injection tanks connected in parallel and first injection pumps connected to the plurality of first low-pressure injection tanks, the first end and the second end of each first low-pressure injection tank are respectively connected to the second water supply system and the first end of the first injection pump, and the second end of the first injection pump is connected to the inlet main pipeline 001. Optionally, the first injection pump is a centrifugal pump.

[0062] In a possible design, the low-pressure injection unit further includes a third water supply solenoid valve, which is arranged in the passage between the second water supply system and each first low-pressure injection tank. Figure 1 As shown, the first low-pressure injection branch includes two first low-pressure injection tanks 301 and 302 connected in parallel, a third water supply solenoid valve 316 is provided in the passage between the first low-pressure injection tank 301 and the second water supply system, and a third water supply solenoid valve 317 is provided in the passage between the first low-pressure injection tank 302 and the second water supply system. Of course, the number of low-pressure injection tanks can be any number set according to the emergency cooling demand, and is not limited to the two shown in the figure.

[0063] The second low-pressure injection branch includes a plurality of second low-pressure injection tanks connected in parallel and second injection pumps connected to the plurality of second low-pressure injection tanks, the first end and the second end of each second low-pressure injection tank are respectively connected to the second water supply system and the first end of the second injection pump, and the second end of the second injection pump is connected to the outlet main pipeline 002. Optionally, the second injection pump is a centrifugal pump.

[0064] In a possible design, the low-pressure injection unit further includes a fourth water supply solenoid valve. The fourth water supply solenoid valve is arranged in the passage between the second water supply system and each second low-pressure injection tank. Figure 1 As shown, the first low-pressure injection branch includes two second low-pressure injection tanks 401 and 402 connected in parallel, a fourth water supply solenoid valve 416 is provided in the passage between the second low-pressure injection tank 401 and the second water supply system, and a fourth water supply solenoid valve 417 is provided in the passage between the second low-pressure injection tank 402 and the second water supply system. Of course, the number of second low-pressure injection tanks can be any number set according to the emergency cooling demand, and is not limited to the two shown in the figure.

[0065] In a possible design, a low-pressure stop valve is provided between each first low-pressure safety injection tank and the corresponding first safety injection pump, and between each second low-pressure safety injection tank and the corresponding second safety injection pump.

[0066] Reference Figure 1As shown, the first low-pressure injection branch includes two first low-pressure injection tanks 301 and 302 in parallel, a low-pressure stop valve 304 is provided between the first low-pressure injection tank 301 and the first injection pump 306, and a low-pressure stop valve 303 is provided between the first low-pressure injection tank 302 and the first injection pump 305. Of course, the number of low-pressure injection tanks and the number of injection pumps can be any number set according to the emergency cooling requirements, and are not limited to the two shown in the figure. In addition, the second low-pressure injection branch includes two second low-pressure injection tanks 401 and 402 in parallel, a low-pressure stop valve 404 is provided between the second low-pressure injection tank 401 and the second injection pump 406, and a low-pressure stop valve 403 is provided between the second low-pressure injection tank 402 and the second injection pump 405. Of course, the number of low-pressure injection tanks and the number of injection pumps can be any number set according to the emergency cooling requirements, and are not limited to the two shown in the figure.

[0067] The first high-pressure gas source drives the cooling liquid in the first high-pressure injection tank 101 to the in-pile fuel irradiation test circuit through the inlet main pipeline 001 by gas expansion, and the second high-pressure gas source drives the cooling liquid in the second high-pressure injection tank 201 to the in-pile fuel irradiation test circuit through the outlet main pipeline 002 by gas expansion. Similarly, when the first injection pump is working, it drives the cooling liquid in the corresponding first low-pressure injection tank to the in-pile fuel irradiation test circuit through the inlet main pipeline 001, and when the second injection pump is working, it drives the cooling liquid in the corresponding second low-pressure injection tank to the in-pile fuel irradiation test circuit through the outlet main pipeline 002.

[0068] As a result, the three-level injection scheme of high pressure, medium pressure and low pressure in the related technology is simplified to a two-level injection scheme of high pressure and low pressure, which simplifies the configuration of the system. Among them, the high-pressure injection unit is driven by a high-pressure gas source instead of a high-pressure injection pump, which reduces the driving cost. As a result, the economy of the circuit construction is improved and the limited space resources in the reactor sealing plant can be saved. At the same time, the number of injection tanks in the low-pressure injection unit is increased, and the storage capacity of the injection cooling liquid is increased, which can ensure that the fuel elements are cooled for a long time, thereby improving the safety performance. Furthermore, the four injection tanks and four injection pumps of the low-pressure injection unit constitute independent injection units. After any injection unit fails, the injection effect will not be affected, which improves the reliability of the emergency cooling system.

[0069] In addition, a pressure monitoring point is set between the two electric isolation valves between the safety injection pipeline and the main pipeline, which can monitor the pressure of the safety injection pipeline in real time during debugging and operation, ensure the integrity of the main system pressure boundary, and improve the stability of system operation.

[0070] In a possible design, the first high-pressure safety injection tank 101, the second high-pressure safety injection tank 201, the first low-pressure safety injection tank 301 and 302, and the second low-pressure safety injection tank 401 and 402 each have a first isolation unit, a second isolation unit, and a third isolation unit arranged in series on the water supply passage connected to the in-core fuel irradiation test circuit.

[0071] The first isolation unit includes a plurality of electric stop valves arranged in parallel, referring to Figure 1 As shown, the first isolation unit of the first high-pressure safety injection branch includes electric stop valves 102 and 114 connected in parallel, the first isolation unit of the second high-pressure safety injection branch includes electric stop valves 203 and 215 connected in parallel, the first isolation unit of the first low-pressure safety injection branch includes electric stop valves 309 and 318 connected in parallel, and the first isolation unit of the second low-pressure safety injection branch includes electric stop valves 409 and 418 connected in parallel.

[0072] The second isolation unit includes a plurality of isolation solenoid valves arranged in parallel, Figure 1 As shown, the second isolation unit of the first high-pressure injection branch includes isolation solenoid valves 115 and 103 connected in parallel, the second isolation unit of the second high-pressure injection branch includes isolation solenoid valves 202 and 214 connected in parallel, the second isolation unit of the first low-pressure injection branch includes isolation solenoid valves 310 and 319 connected in parallel, and the second isolation unit of the second low-pressure injection branch includes isolation solenoid valves 410 and 419 connected in parallel.

[0073] The third isolation unit comprises at least one total check valve, referring to Figure 1 As shown, the third isolation unit of the first high-pressure safety injection branch includes a total check valve 104, the third isolation unit of the second high-pressure safety injection branch includes a total check valve 204, the third isolation unit of the first low-pressure safety injection branch includes a total check valve 311, and the third isolation unit of the second low-pressure safety injection branch includes a total check valve 411.

[0074] In addition, a third pressure monitoring device is provided between the first isolation unit and the second isolation unit. Figure 1 As shown, a third pressure monitoring device 117 is arranged between the first isolation unit and the second isolation unit of the first high-pressure injection branch, a third pressure monitoring device 217 is arranged between the first isolation unit and the second isolation unit of the second high-pressure injection branch, a third pressure monitoring device 320 is arranged between the first isolation unit and the second isolation unit of the first low-pressure injection branch, and a third pressure monitoring device 420 is arranged between the first isolation unit and the second isolation unit of the second low-pressure injection branch.

[0075] Therefore, a dual solenoid valve solution of double electric stop valves connected in parallel and then in series is adopted between the safety injection pipeline and the main pipeline. This not only ensures the isolation effect between the safety injection pipeline and the main pipeline, but also achieves the purpose of not affecting the safety injection effect when individual valves fail, thereby improving the reliability of the system.

[0076] In addition, the second end of the first injection pump is connected to the corresponding first isolation unit via the first low-pressure check valve. Figure 1 As shown, the first low-pressure check valve includes 307 and 308. The second end of the second injection pump is connected to the corresponding first isolation unit via the second low-pressure check valve. Figure 1 As shown, the second low-pressure check valve includes 407 and 408 .

[0077] In a possible design, the low-pressure injection part further includes a third low-pressure check valve, Figure 1 As shown, the third low-pressure check valves 312 , 314 , 412 , 414 are respectively arranged on the first low-pressure safety injection tanks 301 and 302 and the second low-pressure safety injection tanks 401 and 402 .

[0078] In another embodiment of the present application, Figure 1 As shown, the emergency cooling system for the in-core fuel irradiation test circuit includes a passive high-pressure injection unit and a highly reliable low-pressure injection unit. The high-pressure injection unit and the low-pressure injection unit are each provided with two independent injection water sources, drive equipment, and injection pipelines, which are respectively connected to the inlet main pipeline 001 and the outlet main pipeline 002 of the in-core fuel irradiation test circuit.

[0079] The high-pressure injection unit uses high-pressure gas cylinders 105, 106, 205, and 206 to provide driving force, wherein the high-pressure gas cylinders can be selected as high-pressure nitrogen cylinders. First, the cooling water in the first high-pressure injection tank 101 and the second high-pressure injection tank 201 is driven to enter the system, the triggering pressure is not less than 60% of the normal operating pressure of the in-pile fuel irradiation test circuit, the high-pressure injection flow is not less than 10% of the rated flow of the fuel test, and the volume of cooling water stored in the first high-pressure injection tank 101 and the second high-pressure injection tank 201 is not less than 0.5h of usage.

[0080] The low-pressure injection unit uses the first injection pump 305, 306 and the second injection pump 405, 406 to provide driving force. Optionally, the first injection pump and the second injection pump are centrifugal pumps. The cooling water in the first low-pressure injection tank 301, 302 and the second low-pressure injection tank 401, 402 is driven into the system, the triggering pressure is not less than 0.5MPa, the low-pressure injection flow is not less than 10% of the fuel test rated flow, and the volume of cooling water stored in the first low-pressure injection tank 301, 302 and the second low-pressure injection tank 401, 402 is not less than 1.5h of usage.

[0081] Optionally, the cooling water of all the injection tanks is provided by the water feed system of the reactor, wherein at least two isolation valves 110 and 111 are arranged between the first high-pressure injection tank 101 and the water feed system, at least two isolation valves 210 and 211 are arranged between the second high-pressure injection tank 201 and the water feed system, and at least one isolation valve is arranged between the first low-pressure injection tank 301, 302 and the second low-pressure injection tank 401, 402 and the water feed system, which are 316, 217, 416, 417 respectively.

[0082] Optionally, the first low-pressure safety injection tank 301, 302 and the second low-pressure safety injection tank 401, 402 are connected to the second water supply system, and the first high-pressure safety injection tank 101 and the second high-pressure safety injection tank 201 are connected to the first water supply system to ensure that when a failure occurs in the passage or water supply system on one side of the high pressure and low pressure, a certain emergency cooling function can still be retained for the system.

[0083] Optionally, each injection pipeline is provided with a parallel backup valve on each isolation valve while ensuring double valve isolation from the main system, and the isolation valves use valves of different categories.

[0084] Optionally, high-pressure safety injection pipeline pressure monitoring points, i.e., 117 and 217, and low-pressure safety injection pipeline pressure monitoring points, i.e., 320 and 420, are set between the two isolation valves connecting each injection line to the main system. These pressure monitoring points are used to monitor whether there is valve leakage during commissioning and operation, and to monitor the integrity of the main system pressure boundary.

[0085] In any of the above embodiments, the nuclear safety level of each injection box, stop valve, check valve, electric stop valve, solenoid valve, safety valve, centrifugal pump, injection pipeline, etc. is at least safety level 3, the nuclear safety level of each electric stop valve, solenoid valve, safety valve, centrifugal pump power supply system is 1E, and the nuclear safety level of each pressure monitoring instrument and liquid level monitoring instrument is 1E.

[0086] Furthermore, the high-pressure injection section is composed of two independent branches, which are respectively connected to the inlet main pipeline 001 and the outlet main pipeline 002 of the in-core fuel irradiation test circuit. In each independent branch, two high-pressure gas cylinders are arranged in parallel to form the driving gas source of the high-pressure injection section. After parallel connection, the outlet is connected to the pressure reducing valve, and after pressure reduction, it is connected to the pipe of the upper air space of the high-pressure injection tank. A solenoid valve is arranged between the pressure reducing valve and the pipe. The top of the high-pressure injection tank is respectively provided with a water inlet pipe and an overpressure exhaust pipe. The water inlet pipe is connected to the first water supply system of the reactor through a manual stop valve and a water supply solenoid valve in series, and the overpressure exhaust pipe is connected to the safety valve through at least one isolation valve. A pressure monitoring point and a liquid level monitoring point are arranged on the side of the high-pressure injection tank. The pressure signal is interlocked with the outlet solenoid valve of the nitrogen cylinder, and the liquid level signal is interlocked with the water supply solenoid valve.

[0087] When the pressure of the upper air cavity of the high-pressure injection tank is lower than the set value, open the corresponding valve to add air to it. When the pressure of the upper air cavity of the high-pressure injection tank reaches the set value, close the valve. Similarly, when the liquid level inside the high-pressure injection tank is lower than the set value, open the corresponding valve to add water to it. When the liquid level reaches the set value, close the valve.

[0088] Furthermore, the low-pressure injection section is composed of two independent branches, which are respectively connected to the inlet main pipeline 001 and the outlet main pipeline 002 of the in-core fuel irradiation test circuit. Each branch includes two low-pressure injection tanks. The two low-pressure injection tanks of each branch constitute two independent injection water sources and drive facilities for each other. The liquid level gauge of each low-pressure injection tank is interlocked with the water supply solenoid valve on the top of the low-pressure injection tank. When the liquid level of the low-pressure injection tank is lower than the set value, open the corresponding valve to replenish water, and close the valve when the liquid level reaches the upper limit.

[0089] Optionally, each injection pipeline is provided with a parallel backup valve on the basis of ensuring double valve isolation from the main system. At the same time, the isolation valves use different types of valves, such as electric stop valves and solenoid valves, which can reduce the probability of conjugate failure of the equipment.

[0090] In another embodiment of the present application, in response to the acquisition of the high-pressure injection signal, valves 102, 114, 202, 214 and 103, 115, 203, 215 are opened simultaneously, and the high-pressure injection unit injects water into the inlet main pipeline 001 and the outlet main pipeline 002 respectively.

[0091] In response to the acquisition of the low-pressure injection signal, the first injection pump 305 or 405, the second injection pump 306 or 406, and the valves on the respective passages of the first injection pump and the second injection pump are opened simultaneously, so that the low-pressure injection part injects water into the inlet main pipeline 001 and the outlet main pipeline 002. At this time, any injection pump of the inlet injection line can be closed by remote operation, and any injection pump in the outlet injection line can be closed. After the liquid level of the low-pressure injection tank drops to the lower limit, at least one of the injection pumps that has been closed can be remotely reopened to ensure that the cooling time of the test fuel in the low-pressure injection is not less than 3 hours.

[0092] The above technical solution is equipped with independent injection water sources, driving equipment, and injection pipelines in the high-pressure injection section and the low-pressure injection section, respectively, which are connected to the inlet and outlet main pipelines of the in-core fuel irradiation test circuit. On the premise of ensuring the safety function, the configuration of the emergency cooling system of the test circuit is optimized, the economic efficiency of the circuit construction is improved, and the limited space resources in the reactor sealing plant are saved.

[0093] The technical solution of the present application is described in detail above in conjunction with the accompanying drawings. Through the technical solution of the present application, the configuration of the emergency cooling system can be simplified, the driving cost and the occupation of limited space resources in the reactor sealing building can be reduced, the storage capacity of the injection cooling liquid can be increased to ensure that the fuel elements are cooled for a long time, and multiple backup valves can be added to improve the overall reliability of the system.

[0094] It should be understood that although the terms first, second, etc. may be used to describe the high-voltage injection branch in the embodiments of the present application, these high-voltage injection branches should not be limited to these terms. These terms are only used to distinguish the high-voltage injection branches from each other. For example, without departing from the scope of the embodiments of the present application, the first high-voltage injection branch may also be referred to as the second high-voltage injection branch, and similarly, the second high-voltage injection branch may also be referred to as the first high-voltage injection branch.

[0095] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments, and are not intended to limit the present application. The singular forms "a", "said" and "the" used in the embodiments of the present application and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings.

[0096] The embodiments described above are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included in the protection scope of the present invention.

Claims

1. An emergency cooling system for a reactor fuel irradiation test circuit, characterized in that: include: The high-pressure injection unit connects the first water supply system with the in-pile fuel irradiation test circuit. The high-pressure injection section includes a first high-pressure injection branch section and a second high-pressure injection branch section. The first high-pressure safety injection branch comprises a first high-pressure safety injection tank, the first end, the second end and the third end of the first high-pressure safety injection tank are respectively connected to the first water supply system, the inlet main pipeline of the in-core fuel irradiation test circuit and the first high-pressure gas source; the second high-pressure safety injection branch comprises a second high-pressure safety injection tank, the first end, the second end and the third end of the second high-pressure safety injection tank are respectively connected to the first water supply system, the outlet main pipeline of the in-core fuel irradiation test circuit and the second high-pressure gas source, The first high-pressure gas source drives the cooling liquid in the first high-pressure injection tank to the in-core fuel irradiation test circuit through the inlet main pipeline by gas expansion, and the second high-pressure gas source drives the cooling liquid in the second high-pressure injection tank to the in-core fuel irradiation test circuit through the outlet main pipeline by gas expansion; The low-pressure injection unit is connected in parallel with the high-pressure injection unit, and is connected to the second water supply system and the in-pile fuel irradiation test circuit. Wherein, the low-pressure injection part includes a first low-pressure injection branch part and a second low-pressure injection branch part. The first low-pressure injection branch includes a plurality of first low-pressure injection tanks connected in parallel and a first injection pump connected to each of the plurality of first low-pressure injection tanks, the first end and the second end of each of the first low-pressure injection tanks are respectively connected to the second water supply system and the first end of the first injection pump, and the second end of the first injection pump is connected to the inlet main pipeline. The second low-pressure injection branch includes a plurality of second low-pressure injection tanks connected in parallel and a second injection pump connected to each of the plurality of second low-pressure injection tanks, the first end and the second end of each of the second low-pressure injection tanks are respectively connected to the second water supply system and the first end of the second injection pump, and the second end of the second injection pump is connected to the outlet main pipeline. When the first injection pump is working, the cooling liquid in the corresponding first low-pressure injection tank is driven through the inlet main pipeline to the in-pile fuel irradiation test circuit. When the second injection pump is working, the cooling liquid in the corresponding second low-pressure injection tank is driven through the outlet main pipeline to the in-pile fuel irradiation test circuit.

2. The system according to claim 1, characterized in that The high-pressure injection unit also includes: A first manual stop valve and a first water supply solenoid valve are arranged in series in the passage between the first water supply system and the first high-pressure injection tank; A second manual stop valve and a second water supply solenoid valve are arranged in series in the passage between the first water supply system and the second high-pressure injection tank; The low-pressure injection unit also includes: A third water supply solenoid valve is provided in the passage between the second water supply system and each of the first low-pressure injection tanks; The fourth water supply solenoid valve is arranged in the passage between the second water supply system and each of the second low-pressure injection tanks.

3. The system according to claim 2, characterized in that The high-pressure injection unit also includes: A first liquid level monitoring device is arranged at the first high-pressure injection tank and connected to the first water supply solenoid valve; The second liquid level monitoring device is arranged at the second high-pressure injection tank and connected to the second water supply solenoid valve.

4. The system according to claim 1, characterized in that The high-pressure injection unit also includes: A first pressure reducing valve and a first gas cylinder solenoid valve are arranged in series between the first high-pressure gas source and the first high-pressure injection box, wherein the first high-pressure gas source includes a plurality of high-pressure gas cylinders connected in parallel; A second pressure reducing valve and a second gas cylinder solenoid valve are arranged in series between the second high-pressure gas source and the second high-pressure injection box, wherein the second high-pressure gas source includes a plurality of high-pressure gas cylinders connected in parallel; A first overpressure exhaust pipe and a second overpressure exhaust pipe are respectively connected to the first high-pressure injection tank and the second high-pressure injection tank; A first isolation valve and a first safety valve are arranged in series in the passage between the first high-pressure injection tank and the first overpressure exhaust pipe; The second isolation valve and the second safety valve are arranged in series in the passage between the second high-pressure injection tank and the second overpressure exhaust pipe.

5. The system according to claim 4, characterized in that The high-pressure injection unit also includes: A first pressure monitoring device is arranged at the first high-pressure injection box and connected to the first gas cylinder solenoid valve; The second pressure monitoring device is arranged at the second high-pressure injection box and connected to the second gas cylinder solenoid valve.

6. The system according to claim 1, characterized in that A low-pressure stop valve is provided between each of the first low-pressure injection tanks and the corresponding first injection pump, and between each of the second low-pressure injection tanks and the corresponding second injection pump.

7. The system according to any one of claims 1 to 6, characterized in that The first high-pressure safety injection tank, the second high-pressure safety injection tank, the first low-pressure safety injection tank and the second low-pressure safety injection tank each have a first isolation unit, a second isolation unit and a third isolation unit arranged in series on a water supply passage connected to the in-core fuel irradiation test circuit, wherein: The first isolation unit includes a plurality of electric stop valves arranged in parallel; The second isolation unit includes a plurality of isolation solenoid valves arranged in parallel; The third isolation unit includes at least one total check valve; A third pressure monitoring device is provided between the first isolation unit and the second isolation unit.

8. The system according to claim 7, characterized in that The second end of the first injection pump is connected to the corresponding first isolation unit via a first low-pressure check valve; The second end of the second injection pump is connected to the corresponding first isolation unit via a second low-pressure check valve.

9. The system according to claim 7, characterized in that The low-pressure injection unit also includes: The third low-pressure check valve is arranged on each of the first low-pressure safety injection tanks and each of the second low-pressure safety injection tanks.

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