Irradiation device, connection system and method suitable for lead-bismuth irradiation loop

Abstract

The invention belongs to the technical field of fast neutron research reactor irradiation, and particularly relates to an irradiation device, a connection system and a method suitable for a lead-bismuth irradiation loop. According to the device, an air gap sleeve is placed in a heat insulation pipe, and a gas heat insulation layer is formed between the heat insulation pipe and the air gap sleeve; the pressure pipe is placed in the air gap sleeve, a high-temperature gas layer is formed between the air gap sleeve and the pressure pipe, the flow dividing pipe is placed in the pressure pipe, the test section is placed in the flow dividing pipe, the bottom of the flow dividing pipe is open, a lead-bismuth downward flow channel is formed between the pressure pipe and the flow dividing pipe, and the lead-bismuth downward flow channel returns from the bottom and enters the flow dividing pipe. The heat of the test section is taken away. The device is used for a lead-bismuth loop irradiation test of a lead-bismuth research reactor, provides a technological process and a connection system for connection / decoupling of the lead-bismuth loop and the device, solves the problem of decoupling of the lead-bismuth irradiation device and the loop after shutdown and before discharge of the device, and can also be suitable for decoupling of the lead-bismuth loop and the device of a water-cooling research reactor.

Description

Technical Field

[0001] This invention belongs to the field of fast neutron research reactor irradiation technology, specifically relating to an irradiation device, connection system, and method suitable for lead-bismuth irradiation circuits. Background Technology

[0002] With the development of nuclear energy technology, lead-bismuth reactors (LDBRs) in Generation IV nuclear energy systems have become one of the most promising reactor types, attracting extensive research both domestically and internationally. In-reactor performance verification of fuels and materials is a crucial step in the construction of LBR engineering projects. By obtaining in-reactor performance data of fuels and materials in a lead-bismuth environment, the reliability of materials can be verified, and materials meeting engineering application requirements can be obtained. LBRs are fast neutron reactors. Based on fast neutron research reactors, the construction of lead-bismuth irradiation test loops to test the in-reactor performance of fuels and materials in both lead-bismuth and fast neutron environments is a vital step in verifying fuel and material performance.

[0003] Loop irradiation, relying on an irradiation loop, provides an irradiation environment for the prototype reactor by connecting a loop irradiation device. By simulating the thermal and fluid conditions of the prototype reactor, it irradiates fuel and materials under actual operating conditions, fully verifying the in-reactor performance of fuel and materials under real-world operating conditions, thus strongly supporting the engineering implementation of lead-bismuth reactors. Because the lead-bismuth irradiation loop operates in a heavy liquid metal environment, the temperature of the lead and bismuth within the loop must be maintained above the melting point of lead and bismuth (125°C) at all times to ensure that the lead and bismuth remain in a flowable state. Due to the large number of system devices involved, the irradiation loop is generally constructed within the process room of the research reactor and connected to the loop irradiation device via piping. The loop irradiation device, loaded with the fuel and materials to be irradiated, is generally installed within the irradiation duct of the research reactor.

[0004] During the irradiation test, the loop irradiation device needs to be installed in the reactor before the irradiation test and removed from the reactor after the irradiation test. The lead and bismuth in the loop and device are in a high-temperature and fluid state. Measures need to be taken to decouple the irradiation loop and device, i.e., disconnect the connection, in order to facilitate the subsequent removal of the device from the reactor and the venting of lead and bismuth from the loop.

[0005] The design of the irradiation facility and the auxiliary systems connecting the circuit and the facility are crucial. The irradiation facility is installed on the reactor top cover, and the test section of the irradiation facility is located in the active zone within the reactor, typically at a considerable distance from the reactor top cover. The irradiation circuit is installed in the reactor process room, at a significant distance from the reactor top cover, and is usually not arranged on the same horizontal plane as the irradiation facility. This differs greatly from publicly available lead-bismuth test rigs, making it unfavorable for the filling and evacuation of lead and bismuth in the circuit and facility. Currently, no lead-bismuth irradiation circuits have been constructed domestically or internationally, and the corresponding processes are still under research. Therefore, there are currently no relevant process methods for filling, evacuating, and disconnecting the irradiation circuit and facility from the circuit.

[0006] To adapt to the development of nuclear energy technology and support the loop irradiation test of lead-bismuth fuel and materials, it is necessary to design an irradiation device and connection system suitable for lead-bismuth irradiation loops based on the relevant foundations of the research reactor. This system should meet the connection and decoupling requirements of the lead-bismuth irradiation loop and the device, and support the subsequent lead-bismuth venting of the irradiation loop and the device's entry and exit from the reactor and lead-bismuth venting operations. Summary of the Invention

[0007] The technical problem solved by this invention is to provide a device and connection system suitable for lead-bismuth irradiation circuits, used to solve the connection and disconnection of the irradiation circuit and device during the irradiation test operation of the lead-bismuth irradiation circuit in a research reactor, supporting subsequent lead-bismuth filling and discharge operations of the irradiation circuit and device. This invention addresses the needs of lead-bismuth filling and discharge in lead-bismuth irradiation circuits, and the connection and decoupling problems of the lead-bismuth irradiation circuit and device, by inventing a circuit system for connecting and decoupling lead-bismuth irradiation circuits and devices. This invention also addresses the lead-bismuth filling and discharge of irradiation circuits and devices, and proposes a process method suitable for connecting and decoupling lead-bismuth irradiation circuits and devices.

[0008] The technical solution adopted in this invention is as follows:

[0009] An irradiation device for a lead-bismuth irradiation circuit includes an insulating tube, a gas gap sleeve, a pressure tube, a shunt tube, a test section, a gas insulation layer, a high-temperature gas layer, and a device gas cavity space. The gas gap sleeve is placed inside the insulating tube, forming a gas insulation layer between the insulating tube and the gas gap sleeve. The pressure tube is placed inside the gas gap sleeve, forming a high-temperature gas layer between the gas gap sleeve and the pressure tube. The shunt tube is placed inside the pressure tube, and the test section is placed inside the shunt tube. The bottom of the shunt tube is open, forming a lead-bismuth downward flow channel between the pressure tube and the shunt tube. The lead-bismuth then turns back at the bottom and enters the shunt tube, carrying away the heat from the test section.

[0010] The high-temperature gas layer is provided with a flexible high-temperature gas layer inlet pipeline and a flexible high-temperature gas layer outlet pipeline at the top opening. The lead-bismuth downward flow channel is provided with a lead-bismuth inlet pipeline at the top opening. The top opening of the diversion pipe is provided with a gas cavity space pipeline and a lead-bismuth outlet pipeline. The lead-bismuth outlet pipeline is immersed in the lead-bismuth coolant inside the diversion pipe.

[0011] The connection system of the irradiation device for the lead-bismuth irradiation circuit includes a compressor and a first lead-bismuth buffer tank. One end of the compressor is connected to a gas supply pipeline of the gas system, and the other end of the compressor is connected to a first pressure controller. The other end of the first pressure controller is connected to a gas heating device, and the other end of the gas heating device is connected to a first three-way valve. The second end of the first three-way valve is connected to the top of the first lead-bismuth buffer tank via a pipeline, and the third end of the first three-way valve is connected to a gas chamber space pipeline. A second pressure controller is provided on the top of the first lead-bismuth buffer tank. One end of the first lead-bismuth buffer tank is connected to a second three-way valve via a pipeline. The second end of the second three-way valve is connected to the lead-bismuth circuit inlet pipeline, and the third end of the second three-way valve is connected to the lead-bismuth circuit outlet pipeline via a pipeline. The other end of the first lead-bismuth buffer tank is connected to the lead-bismuth inlet pipeline via a pipeline, and the lead-bismuth circuit outlet pipeline is connected to the lead-bismuth outlet pipeline. The lead-bismuth circuit inlet pipeline, the lead-bismuth inlet pipeline, the lead-bismuth outlet pipeline, and the lead-bismuth circuit outlet pipeline constitute a first circuit.

[0012] The gas system supply pipeline is equipped with a gas electric valve, the compressor is connected in parallel with a gas electric valve, the pipeline connecting the third port of the first three-way valve to the gas chamber space pipeline is equipped with a gas electric valve, a third pressure controller and a pressure gauge; the first lead-bismuth buffer tank is equipped with a pressure gauge.

[0013] A lead-bismuth electric valve is installed on the pipeline connecting the first lead-bismuth buffer tank and the second three-way valve. A lead-bismuth check valve and a lead-bismuth electric valve are installed on the pipeline connecting the third of the second three-way valve and the lead-bismuth circuit outlet pipeline. A lead-bismuth electric valve and a lead-bismuth electric valve are installed on the pipeline connecting the first lead-bismuth buffer tank and the lead-bismuth inlet pipeline. A lead-bismuth electric valve, a lead-bismuth check valve, a lead-bismuth electric valve, and a lead-bismuth electric valve are sequentially installed on the lead-bismuth circuit outlet pipeline.

[0014] A bypass line is provided on the pipeline between the gas electric valve and the third pressure controller, and a gas electric valve and an exhaust valve are installed on it.

[0015] A bypass pipeline is provided on the pipeline between the lead-bismuth electric valve and the lead-bismuth electric valve. The bypass pipeline is connected to the second circuit through the lead-bismuth electric valve and the lead-bismuth check valve. The second circuit is provided with a lead-bismuth second buffer tank. A lead-bismuth electromagnetic pump is provided at one end of the lead-bismuth second buffer tank, and a lead-bismuth flow meter is provided at the other end. A lead-bismuth check valve is provided between the lead-bismuth second buffer tanks. A lead-bismuth electric valve is provided between the lead-bismuth flow meter and the lead-bismuth electromagnetic pump. The bypass pipeline is connected to the pipeline between the lead-bismuth electromagnetic pump and the lead-bismuth electric valve. The lead-bismuth storage tank is connected to the pipeline between the lead-bismuth flow meter and the lead-bismuth electric valve through the lead-bismuth electric valve.

[0016] It is also equipped with a loop heat tracing module to ensure that the temperature of all pipelines in the system is above 125°C; a supporting device for stack heating module to achieve heating and insulation of the device, ensuring that the temperature of the area containing lead and bismuth is above 125°C; and an electric valve linkage control module to achieve one-button operation.

[0017] The irradiation method for the connection system includes the following steps:

[0018] Step 1: Irradiation device loading and lead-bismuth filling

[0019] The irradiation device of the lead-bismuth loop is connected to the connection system without filling the lead-bismuth into the stack. The connection system is used to purge air and heat the irradiation device and pipelines. The connection system is also used to fill the pipelines and irradiation device with lead-bismuth.

[0020] Step 2: Stable operation of the irradiation test

[0021] During the stable operation of the irradiation test, the loop heat tracing module realizes the heat preservation and heat tracing of the system, so that the system is in a hot standby state. The lead-bismuth electromagnetic pump, the lead-bismuth second buffer tank, and the lead-bismuth flow meter form a closed loop.

[0022] Step 3: Decoupling of the circuit and device and removal of lead and bismuth

[0023] In step 2, after the irradiation test is completed, the lead-bismuth electromagnetic pump, the second lead-bismuth buffer tank, the lead-bismuth flow meter, and the closed loop are started, while both are in the closed state. The loop flow rate is reduced to decrease the mass of lead-bismuth and thus reduce its inertia. The first and second pressure controllers are connected to the compressor, the gas supply pressure control valve group or pressure controller, and the gas heating device pipeline to monitor and control the pressure changes of the first lead-bismuth buffer tank, the second lead-bismuth buffer tank, and the gas chamber space inside the device. The gas enters the second lead-bismuth buffer tank through the compressor and the gas supply pressure control valve group or pressure controller.

[0024] In step 2, the lead-bismuth electromagnetic pump and the second lead-bismuth buffer tank are not circulated, but they must be kept in a hot standby state so that they can be started at any time.

[0025] The beneficial effects of this invention are:

[0026] This invention provides an irradiation device, connection system, and method suitable for lead-bismuth irradiation circuits, used for lead-bismuth circuit irradiation tests in lead-bismuth research reactors. It provides a process flow and connection system for connecting / decoupling the lead-bismuth circuit and the device, solving the problem of decoupling the device from the circuit after reactor shutdown and before it leaves the reactor. It can also be applied to the decoupling problem of lead-bismuth circuits and devices in water-cooled research reactors. The specific beneficial effects of this invention are as follows:

[0027] (1) The present invention provides an irradiation device and connection system suitable for lead-bismuth irradiation circuits, which can solve the problem of decoupling the lead-bismuth irradiation device from the circuit in the lead-bismuth pile, and proposes an irradiation method for connecting the lead-bismuth irradiation circuit and device, which strongly supports the subsequent emptying operation of the lead-bismuth circuit and the removal operation of the irradiation device from the pile.

[0028] (2) The present invention provides an irradiation device and connection system suitable for lead-bismuth irradiation circuits. Based on conventional water-cooled circuit irradiation devices, a high-temperature gas layer for heating and insulation is designed (an additional sleeve is added); and a device gas cavity space scheme is proposed, using three small gas pipes to solve the problems of preheating and insulation of lead-bismuth irradiation devices and buffering lead-bismuth expansion inside the irradiation device; the outer pipe of the gas gap sleeve adopts a high-temperature resistant flexible pipe connection method such as corrugated pipe, and a simple system is used to realize the internal heating and insulation of the device in the entire process of irradiation device operation.

[0029] (3) The supporting facilities and devices provided by the present invention include a heating module for the device, which provides heating and heat preservation functions and can simultaneously meet the requirements of lead-bismuth irradiation devices in fast neutron reactors and water-cooled research reactors, thus having a wider range of applications.

[0030] (4) The present invention provides an irradiation device and connection system suitable for lead-bismuth irradiation circuits, equipped with electric valves and buffer tanks. Based on existing equipment in the irradiation circuit system or modified from the existing circuit system, the complexity of the system is greatly reduced. At the same time, it solves the problems of lead-bismuth thermal expansion and flow inertia during stable operation and connection / decoupling processes, and provides methods for monitoring pressure and liquid level, which strongly supports operators in making operational judgments and improves safety during connection / decoupling and stable operation.

[0031] (5) The irradiation method proposed in this invention combines gas compression and electromagnetic pump-assisted extraction of lead and bismuth to solve the problems of insufficient head of electromagnetic pump extraction method and slow lead and bismuth removal by gas compression method.

[0032] (6) The irradiation method proposed in this invention adopts a three-step method and sets up a valve interlocking operating system, which can realize one-click decoupling operation, reduce the difficulty of manual operation and the problem of dosage during manual operation. Attached Figure Description

[0033] To more clearly illustrate the embodiments of the present invention, the accompanying drawings used in describing the embodiments of the present invention will be briefly described below. Obviously, the drawings described below are merely some embodiments recorded in the present invention. Those skilled in the art can derive other drawings from the following drawings without any creative effort.

[0034] Figure 1A schematic diagram of an irradiation device structure suitable for a lead-bismuth irradiation circuit provided by the present invention;

[0035] Figure 2 This is a schematic diagram of the connection system structure of the irradiation device;

[0036] In the diagram: 1-Compressor; 2-First pressure controller; 3-Gas heating device; 4-Second pressure controller; 5-Third pressure controller; 6-First lead-bismuth buffer tank; 7-Lead-bismuth electromagnetic pump; 8-Second lead-bismuth buffer tank; 9-Lead-bismuth flow meter; 10-Lead-bismuth storage tank; 11-Circuit heat tracing module; 12-Package heating module; 13-Electric valve linkage control module; V1~V4 are gas electric valves; V5 is exhaust valve; V6~V9, V11~V12, V14~V17, V19 and V20 are lead-bismuth electric valves; V10, V12, V13 and V18 are lead-bismuth check valves;

[0037] The 14-lead-bismuth loop irradiation device mainly consists of: Z1-insulating tube; Z2-air gap sleeve; Z3-pressure tube; Z4-shunt tube; Z5-test section; Z6-gas insulation layer; Z7-high temperature gas layer; Z8-device gas chamber space; L1-high temperature gas layer flexible inlet pipeline; L2-lead-bismuth inlet pipeline; L3-gas chamber space pipeline; L4-lead-bismuth outlet pipeline; L5-high temperature gas layer flexible outlet pipeline. Detailed Implementation

[0038] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present invention.

[0039] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., refer to the orientation or positional relationship shown in the accompanying drawings, and are used only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0040] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or a connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0041] like Figure 1 As shown, the present invention provides an irradiation device for a lead-bismuth irradiation circuit, comprising an insulating tube Z1, a gas gap sleeve Z2, a pressure tube Z3, a shunt tube Z4, a test section Z5, a gas insulation layer Z6, a high-temperature gas layer Z7, and a device gas cavity space Z8. The gas gap sleeve (Z2) is placed inside the insulating tube (Z1), and a gas insulation layer (Z6) is formed between the insulating tube (Z1) and the gas gap sleeve (Z2). The thickness of the tube and the gas layer can be set appropriately according to the temperature of the external coolant to maintain the temperature inside the device. The pressure tube (Z3) is placed inside the air gap sleeve (Z2), forming a high-temperature gas layer (Z7) between the air gap sleeve (Z2) and the pressure tube (Z3). The diverter tube (Z4) is placed inside the pressure tube (Z3), and the test section (Z5) is placed inside the diverter tube (Z4). The bottom of the diverter tube (Z4) is open, and a lead-bismuth downward flow channel is formed between the pressure tube (Z3) and the diverter tube (Z4), which then turns back at the bottom; the lead-bismuth enters the diverter tube (Z4) and carries away the heat of the test section (Z5).

[0042] The high-temperature gas layer (Z7) is provided with a flexible high-temperature gas inlet pipeline L1 and a flexible high-temperature gas outlet pipeline L5 at the top opening. The lead-bismuth downward flow channel is provided with a lead-bismuth inlet pipeline L2 at the top opening. The top opening of the split pipe (Z4) is provided with a gas cavity space pipeline L3 and a lead-bismuth outlet pipeline L4. The lead-bismuth outlet pipeline L4 is immersed in lead-bismuth coolant inside the split pipe (Z4).

[0043] The device is connected to the reactor heating module via high-temperature gas inlet and outlet pipelines (L1 and L2) to heat and maintain the device using high-temperature gas.

[0044] like Figure 2As shown, the present invention provides an irradiation device connection system for a lead-bismuth irradiation circuit, comprising a compressor (1), a first lead-bismuth buffer tank (6), a lead-bismuth electromagnetic pump (7), a second lead-bismuth buffer tank (8), and a lead-bismuth storage tank (10). One end of the compressor (1) is connected to a gas system supply pipeline, and a gas electric valve V1 is provided on the gas system supply pipeline. A gas electric valve V2 is connected in parallel with the compressor (1). The other end of the compressor (1) is connected to a first pressure controller (2), and the other end of the first pressure controller (2) is connected to... A gas heating device (3) is connected, and the other end of the gas heating device (3) is connected to the first three-way valve. The second end of the first three-way valve is connected to the top of the first lead-bismuth buffer tank (6) through a pipeline. A second pressure controller (4) is provided on it. The third end of the first three-way valve is connected to the gas chamber space pipeline L3. A gas electric valve V3, a third pressure controller (5) and a pressure gauge are provided on it. A bypass pipeline is provided on the pipeline between the gas electric valve V3 and the third pressure controller (5). A gas electric valve V4 and an exhaust valve V5 are provided on it.

[0045] The first lead-bismuth buffer tank (6) is equipped with a pressure gauge. One end of the first lead-bismuth buffer tank (6) is connected to the second three-way valve via a pipeline. A lead-bismuth electric valve V6 is installed on the pipeline. The second port of the second three-way valve is connected to the lead-bismuth circuit inlet pipeline. The third port of the second three-way valve is connected to the lead-bismuth circuit outlet pipeline via a pipeline. A lead-bismuth check valve V13 and a lead-bismuth electric valve V14 are installed on the pipeline. The other end of the first lead-bismuth buffer tank (6) is connected to the lead-bismuth inlet pipeline L2 via a pipeline. A lead-bismuth electric valve V7 and a lead-bismuth electric valve V8 are installed on the pipeline. The lead-bismuth circuit outlet pipeline is connected to the lead-bismuth outlet pipeline L4. The lead-bismuth circuit outlet pipeline is equipped with a lead-bismuth electric valve V15, a lead-bismuth check valve V12, a lead-bismuth electric valve V11, and a lead-bismuth electric valve V20 in sequence. The lead-bismuth circuit inlet pipeline, the lead-bismuth inlet pipeline L2, and the lead-bismuth outlet... Pipeline L4 and the lead-bismuth loop outlet pipeline constitute the first loop; a bypass pipeline is provided on the pipeline between the lead-bismuth electric valve V7 and the lead-bismuth electric valve V8, and the bypass pipeline is connected to the second loop through the lead-bismuth electric valve V9 and the lead-bismuth check valve V10. The second loop is provided with a lead-bismuth second buffer tank (8), one end of the lead-bismuth second buffer tank (8) is provided with a lead-bismuth electromagnetic pump (7), and the other end is provided with a lead-bismuth flow meter (9). A lead-bismuth check valve V18 is provided between the lead-bismuth second buffer tanks (8), and a lead-bismuth electric valve V16 is provided between the lead-bismuth flow meter (9) and the lead-bismuth electromagnetic pump (7). The bypass pipeline is connected to the pipeline between the lead-bismuth electromagnetic pump (7) and the lead-bismuth electric valve V16. The lead-bismuth storage tank (10) is connected to the pipeline between the lead-bismuth flow meter (9) and the lead-bismuth electric valve V16 through the lead-bismuth electric valve V19.

[0046] The first pressure control valve group or pressure controller (4) controls the pressure and liquid level in the first lead-bismuth buffer tank (6); the second lead-bismuth buffer tank (8) adopts the same configuration and controls the upper pressure in the tank; the third pressure controller (5) is connected to the gas chamber space (Z8) of the lead-bismuth circuit irradiation device (14) and controls the pressure and liquid level in the device.

[0047] The entire connection system is equipped with a loop heat tracing module (11) to ensure that the temperature of all pipelines in the system is above 125°C. A supporting device, a stack heating module (12), is used to heat and maintain the temperature of the device, ensuring that the temperature of the area containing lead and bismuth is above 125°C. According to the operating process, an electric valve linkage control module (13) is configured to achieve one-button operation.

[0048] The first pressure controller (2), the second pressure controller (4) and the third pressure controller (5) can be gas supply pressure control valve groups.

[0049] The first loop is the steady-state operating condition of the loop irradiation test. The lead-bismuth loop inlet pipeline, V13, V14, V15 and the lead-bismuth loop outlet pipeline form a loop. During the operation of this loop, the loop section can be operated independently by closing the corresponding valves. V8, lead-bismuth loop irradiation device (14), V17, V18, lead-bismuth flow meter (9), V16, lead-bismuth electromagnetic pump (7) and lead-bismuth second buffer tank (8) form a pipeline. During the operation of this loop, the device can be operated independently by closing the corresponding valves, and the lead-bismuth in the device can be buffered and discharged. The lead-bismuth is finally discharged to the lead-bismuth storage tank (10) through valve V19. The pipeline connected to the device is provided with both metal corrugated pipe and steel pipe connection.

[0050] The present invention provides an irradiation device and connection system for a lead-bismuth irradiation circuit, which allows the connection and decoupling of the irradiation device and the circuit to operate independently, and can discharge a certain amount of lead-bismuth from the device. The specific irradiation method is as follows:

[0051] Step 1: Irradiation device loading and lead-bismuth filling process

[0052] The irradiation device for the lead-bismuth loop adopts a non-filled lead-bismuth loading method. If it is a high-temperature coolant fast neutron research reactor irradiation, the device loading heating module is used in conjunction with gas preheating to heat and keep the device warm, reducing the total weight of the device. If it is a low-temperature coolant water-cooled research reactor, the device loading heating module can also be used without using the heating function. After the device is connected to the connection system, the irradiation device and pipelines are treated by air purging and heating through the connection system without adding new auxiliary systems. Due to the need for heat preservation, the system needs to be equipped with a heat tracing module (11) and a heating module (12). After the device is loaded into the reactor, the pipelines and irradiation device are filled with lead-bismuth using the connection system without equipping other auxiliary systems, reducing the construction cost of the loop. During the filling process, the pressure of the device gas chamber space (Z8) of the loop irradiation device (14) changes. The pressure is monitored using a gas pressure gauge. The pressure is directly proportional to the device liquid level, thereby controlling the height of the gas chamber. To facilitate reactor entry and exit operations, the inlet and outlet pipelines of the device can be connected using corrugated metal pipes. Even if severely corroded by lead and bismuth, the corrugated metal pipes can be disposed of as waste after use. The corrugated metal pipes are equipped with expansion joints, providing a buffer function. The device utilizes a flexible inlet pipeline L1 for high-temperature gas to enter the high-temperature gas layer and a flexible outlet pipeline L5 for exiting the high-temperature gas layer, achieving both insulation and heating of the device. This system is suitable for both the high-temperature environment of lead-bismuth reactors and the low-temperature environment of water-cooled research reactors.

[0053] Step 2: Process during stable operation of the irradiation test

[0054] During the stable operation of the irradiation test, the loop heat tracing module (11) provides insulation and heat tracing for the system, keeping it in a hot standby state. During this period, V1-V5, V9, V11, and V14 are in the closed state, while V6-V8, V11, V15, V17, and (V20) are in the open state. The lead-bismuth electromagnetic pump (7), the lead-bismuth second buffer tank (8), the lead-bismuth flow meter (9), and V16 form a closed loop. This loop can operate continuously during the stable operation period, or it can be kept in a hot standby state without circulation, allowing it to be started at any time. During the stable operation period, the lead-bismuth inlet pipeline, the device, and the lead-bismuth outlet pipeline form a circulation through valves, ensuring the stable operation of the irradiation test.

[0055] Step 3: Decoupling of the loop and equipment and lead-bismuth removal process

[0056] In step 2, after the irradiation test is completed, start the lead-bismuth electromagnetic pump (7), the lead-bismuth second buffer tank (8), the lead-bismuth flow meter (9), and V16 closed loop to prepare for the decoupling of the circuit and the device. At this time, V9 and V1,4 are all in the closed state. The irradiation circuit and the device are in the loop connection state. After the above preparations are completed, appropriately reduce the circuit flow rate to reduce the mass of lead-bismuth and thus reduce the inertia of lead-bismuth. Open V9, V14, and V17, close V8 and V11, and open V1, V2, and V3. Through the compressor (1), the gas supply pressure control valve group or pressure controller (2), and the gas heating device (3) pipeline, respectively connect the first pressure control valve group or pressure controller (4) and the second pressure control valve group or pressure controller (5) to monitor and control the pressure changes in the gas chamber space of the lead-bismuth first buffer tank (6), the lead-bismuth second buffer tank (8), and the device (14). During the flow rate change of lead and bismuth, the liquid level in the first lead and bismuth buffer tank (6) will rise due to inertial flow, thereby increasing the pressure. V4 and V5 are opened in a timely manner to release gas pressure and maintain a stable pressure change. The lead and bismuth loop inlet pipeline circulates through V13, V14, and V15; in the device section, it enters the second lead and bismuth buffer tank (8) through (V20) and V17. The pressure and liquid level of the two buffer tanks are monitored, and V6 is closed. At this time, the loop and the device are completely decoupled, and the lead and bismuth venting and other operations of the loop can be performed independently.

[0057] Due to the inertia of lead and bismuth, the flow within the device enters the second buffer tank through V17 until the lead and bismuth flow within the device stops. At this point, V4 and V5 are closed, increasing the pressure within the device's gas chamber and forcing the lead and bismuth to flow in the reverse direction, entering the second lead and bismuth buffer tank through V8 and V9. The total amount of remaining lead and bismuth in the device is controlled by monitoring the gas chamber pressure. During operation, the pressure and liquid level of each tank are monitored, and V19 is opened as needed to drain excess lead and bismuth from the system.

[0058] Based on the status and control of the electric valves in the operating process, configure the electric valve linkage control, and achieve one-button operation through electric valve interlocking, pressure, liquid level, temperature signals, etc.

[0059] This invention proposes an irradiation device scheme, which adopts a double-gap layer structure. The outer insulating tube and the air gap sleeve are filled with inert gas for insulation. The space between the air gap sleeve and the pressure tube is connected by a flexible pipeline, which can be filled with high-temperature inert gas. The irradiation device's shunt pipe uses high-pressure gas to form a gas cavity space, and the lead-bismuth expands in the buffer device. This invention proposes a connection system for lead-bismuth irradiation and the device. Buffer tanks and electric control valves are added to the inlet and outlet pipes. A metal corrugated pipe connection process for the device's inlet and outlet is proposed to solve the problem of large flow inertia of lead-bismuth during the decoupling process between the loop and the device. A supporting facility device loading heating module is proposed to meet the loading and unloading needs of both high-temperature fast neutron research reactors and low-temperature water-cooled research reactors. Before the decoupling of the loop and the device, the connection system forms a closed loop with the lead-bismuth electromagnetic pump (7), the lead-bismuth second buffer tank (8), the lead-bismuth check valve V-18, and the lead-bismuth flow meter (9), which is in a hot standby state.

[0060] The device employs a double-gap layer and a built-in gas chamber design within the shunt tube. This increases the internal space of the gas gap sleeve, allowing connection to an external gas system. The external circuit system uses the inert gas Ar, whose low thermal conductivity allows for a larger temperature gradient, reducing the gas layer thickness. If the irradiation channel space is sufficient, other gases such as He and N2 can be used. The built-in gas chamber design allows for control of the lead-bismuth liquid level within the irradiation device and includes a reserved pressure control interface to buffer volume changes such as thermal expansion of the lead-bismuth within the device.

[0061] Using flexible pipelines such as corrugated pipes for connection, which takes into account both flexibility and sealing, can prevent the leakage of gas released during irradiation. At the same time, during the loading, unloading and transportation of the irradiation device, the high-temperature gas in the flexible pipeline can achieve the preheating and heat preservation functions of the device.

[0062] While those skilled in the art will recognize that the present invention is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention, the embodiments should be considered illustrative and non-limiting in all respects. The scope of the invention is defined by the appended claims rather than the foregoing description, and therefore all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0063] Furthermore, it should be understood that although the present invention is described according to embodiments, not every embodiment contains only one independent technical solution. This way of describing the specification is only for clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. An irradiation device for a lead-bismuth irradiation circuit, characterized in that, The device includes an insulating tube (Z1), an air gap sleeve (Z2), a pressure tube (Z3), a distribution tube (Z4), a test section (Z5), a gas insulation layer (Z6), a high-temperature gas layer (Z7), and a device gas cavity space (Z8). The air gap sleeve (Z2) is placed inside the insulating tube (Z1), forming a gas insulation layer (Z6) between the insulating tube (Z1) and the air gap sleeve (Z2). The pressure tube (Z3) is placed inside the air gap sleeve (Z2), forming a high-temperature gas layer (Z7) between the air gap sleeve (Z2) and the pressure tube (Z3). The distribution tube (Z4) is placed inside the pressure tube (Z3), and the test section (Z5) is placed inside the distribution tube (Z4). The bottom of the distribution tube (Z4) is open, and a lead-bismuth downward flow channel is formed between the pressure tube (Z3) and the distribution tube (Z4), which then turns back at the bottom and enters the distribution tube (Z4), carrying away the heat from the test section (Z5).

2. The irradiation apparatus for the lead-bismuth irradiation circuit according to claim 1, characterized in that, The high-temperature gas layer (Z7) is provided with a flexible high-temperature gas inlet pipeline (L1) and a flexible high-temperature gas outlet pipeline (L5) at the top opening. The lead-bismuth downward flow channel is provided with a lead-bismuth inlet pipeline (L2) at the top opening. The top opening of the split pipe (Z4) is provided with a gas cavity space pipeline (L3) and a lead-bismuth outlet pipeline (L4). The lead-bismuth outlet pipeline (L4) is immersed in the lead-bismuth coolant inside the split pipe (Z4).

3. The connection system of the irradiation device based on the lead-bismuth irradiation circuit of claim 2, characterized in that, The system includes a compressor (1) and a first lead-bismuth buffer tank (6). One end of the compressor (1) is connected to the gas supply line of the gas system, and the other end of the compressor (1) is connected to a first pressure controller (2). The other end of the first pressure controller (2) is connected to a gas heating device (3), and the other end of the gas heating device (3) is connected to a first tee. The second end of the first tee is connected to the top of the first lead-bismuth buffer tank (6) via a pipeline, and the third end of the first tee is connected to the gas chamber space pipeline (L3). The top of the first lead-bismuth buffer tank (6) is equipped with... There is a second pressure controller (4). One end of the first lead-bismuth buffer tank (6) is connected to the second three-way valve through a pipeline. The second port of the second three-way valve is connected to the lead-bismuth circuit inlet pipeline. The third port of the second three-way valve is connected to the lead-bismuth circuit outlet pipeline through a pipeline. The other end of the first lead-bismuth buffer tank (6) is connected to the lead-bismuth inlet pipeline (L2) through a pipeline. The lead-bismuth circuit outlet pipeline is connected to the lead-bismuth outlet pipeline (L4). The lead-bismuth circuit inlet pipeline, the lead-bismuth inlet pipeline (L2), the lead-bismuth outlet pipeline (L4) and the lead-bismuth circuit outlet pipeline constitute the first circuit.

4. The connection system according to claim 3, characterized in that, The gas system supply pipeline is equipped with a gas electric valve (V1), the compressor (1) is connected in parallel with a gas electric valve (V2), the pipeline connecting the third port of the first three-way valve to the gas chamber space pipeline (L3) is equipped with a gas electric valve (V3), a third pressure controller (5) and a pressure gauge; the first lead-bismuth buffer tank (6) is equipped with a pressure gauge.

5. The connection system according to claim 4, characterized in that, A lead-bismuth electric valve (V6) is provided on the pipeline connecting the first lead-bismuth buffer tank (6) and the second three-way valve. A lead-bismuth check valve (V13) and a lead-bismuth electric valve (V14) are provided on the pipeline connecting the third of the second three-way valve and the lead-bismuth circuit outlet pipeline. A lead-bismuth electric valve (V7) and a lead-bismuth electric valve (V8) are provided on the pipeline connecting the first lead-bismuth buffer tank (6) and the lead-bismuth inlet pipeline (L2). A lead-bismuth electric valve (V15), a lead-bismuth check valve (V12), a lead-bismuth electric valve (V11), and a lead-bismuth electric valve (V20) are provided in sequence on the lead-bismuth circuit outlet pipeline.

6. The connection system according to claim 5, characterized in that, A bypass line is provided on the pipeline between the gas electric valve (V3) and the third pressure controller (5), and a gas electric valve (V4) and an exhaust valve (V5) are provided on it.

7. The connection system according to claim 6, characterized in that, A bypass pipeline is provided on the pipeline between the lead-bismuth electric valve (V7) and the lead-bismuth electric valve (V8). The bypass pipeline is connected to the second circuit through the lead-bismuth electric valve (V9) and the lead-bismuth check valve (V10). The second circuit is provided with a lead-bismuth second buffer tank (8). One end of the lead-bismuth second buffer tank (8) is provided with a lead-bismuth electromagnetic pump (7), and the other end is provided with a lead-bismuth flow meter (9). A lead-bismuth check valve (V18) is provided between the lead-bismuth second buffer tanks (8). A lead-bismuth electric valve (V16) is provided between the lead-bismuth flow meter (9) and the lead-bismuth electromagnetic pump (7). The bypass pipeline is connected to the pipeline between the lead-bismuth electromagnetic pump (7) and the lead-bismuth electric valve (V16). The lead-bismuth storage tank (10) is connected to the pipeline between the lead-bismuth flow meter (9) and the lead-bismuth electric valve (V16) through the lead-bismuth electric valve (V19).

8. The connection system according to claim 7, characterized in that, It is also equipped with a loop heat tracing module (11) to ensure that the temperature of all pipelines in the system is higher than 125°C; a matching device stack heating module (12) is provided to heat and keep the device warm, so that the temperature of the area containing lead and bismuth in the device is higher than 125°C; and an electric valve linkage control module (13) is configured to realize one-button operation.

9. The irradiation method based on the connection system of claim 8, characterized in that, Includes the following steps: Step 1: Irradiation device loading and lead-bismuth filling The irradiation device of the lead-bismuth loop is connected to the connection system without filling the lead-bismuth into the stack. The connection system is used to purge air and heat the irradiation device and pipelines. The connection system is also used to fill the pipelines and irradiation device with lead-bismuth. Step 2: Stable operation of the irradiation test During the stable operation of the irradiation test, the loop heat tracing module (11) realizes the heat preservation and heat tracing of the system, so that the system is in a hot standby state. Valves (V1)~(V5), (V9), (V11), and (V14) are in the closed state, and valves (V6)~(V8), (V11), (V15), (V17), and (V20) are in the open state. The lead-bismuth electromagnetic pump (7), the lead-bismuth second buffer tank (8), the lead-bismuth flow meter (9), and (V16) form a closed loop. Step 3: Decoupling of the circuit and device and removal of lead and bismuth In step 2, after the irradiation test is completed, the lead-bismuth electromagnetic pump (7), the lead-bismuth second buffer tank (8), the lead-bismuth flow meter (9), and (V16) are started in a closed loop. At this time, (V9) and (V14) are both in the closed state. The loop flow rate is reduced to decrease the mass of lead-bismuth and thus reduce the inertia of lead-bismuth. (V9), (V14), and (V17) are opened, (V8) and (V11) are closed, and (V1), (V2), and (V3) are opened. Through the compressor (1), the gas supply pressure control valve group or the pressure controller (2), and the gas heating device (3) pipeline, the first pressure controller (4) and the second pressure controller (5) are connected to monitor and control the pressure changes in the gas chamber space of the lead-bismuth first buffer tank (6), the lead-bismuth second buffer tank (8), and the device (14). The gas enters the lead-bismuth second buffer tank (8) through (V20) and (V17).

10. The irradiation method according to claim 9, characterized in that, In step 2, the lead-bismuth electromagnetic pump (7) and the second lead-bismuth buffer tank (8) are not circulated but are kept in a hot standby state so that they can be started at any time.

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