Irradiation and hydrochemical corrosion test system in high-flux neutron environment

Abstract

The invention relates to the technical field of research of reactor material irradiation, and provides an irradiation and water chemical corrosion test system in a high-flux neutron environment, the irradiation and water chemical corrosion test system comprises a pressurizing unit, an in-reactor test device and a heat exchanger, the pressurizing unit comprises a first pressurizing pump, a second pressurizing pump and a first bypass valve which are arranged in parallel, a test sample is placed in the in-pile test device, the in-pile test device is placed in the neutron field, the heat exchanger is connected with a second bypass valve in parallel, the pipeline is hooped and sleeved with a heater, and through cooperation of the pressurization unit, the heater and the in-pile test device placed in the neutron field, a medium flowing in the pipeline is high-temperature and high-pressure water containing radioactivity; the in-reactor water environment can be simulated more accurately, material irradiation tests in high-temperature and high-pressure field, high-flux neutron field and radiation field environments are achieved, the reliability of test results is improved, and the temperature, flow and pressure of the system are flexibly adjusted by adjusting the opening degree of the first bypass valve and the opening degree of the second bypass valve.

Description

Technical Field

[0001] The invention relates to the technical field of research reactor material irradiation, and in particular to an irradiation and water chemical corrosion test system in a high-flux neutron environment. Background Art

[0002] During the development of pressurized water reactor materials, it is necessary to conduct irradiation assessment and water chemical corrosion tests on the materials. Establishing a high-temperature and high-pressure irradiation test circuit in the research reactor to simulate the actual pressurized water reactor operating environment can provide a test environment for irradiation assessment, study the structural and performance changes of materials under the action of particles and their change laws, and explore the corrosion characteristics of materials under different water quality conditions (pH, conductivity, ion concentration). However, the corrosion characteristics of materials after irradiation in the reactor are different from those under non-nuclear conditions. Currently, most material irradiation assessments use gamma ray irradiation, and there is a lack of research on material water chemical corrosion under high-flux neutron conditions. Summary of the invention

[0003] The purpose of the present invention is to provide an irradiation and water chemical corrosion test system in a high-flux neutron environment to solve the above-mentioned technical problems, accurately simulate the water environment inside the reactor, realize material irradiation testing in high-temperature and high-pressure fields, high-flux neutron fields and radiation fields, improve the reliability of the test results, and realize flexible adjustment of system temperature, flow and pressure.

[0004] The present invention is achieved through the following technical scheme: an irradiation and water chemical corrosion test system in a high-flux neutron environment, including a booster unit, an in-pile test device and a heat exchanger which are connected in sequence by pipelines to form a loop, the booster unit includes a first booster pump, a second booster pump and a first bypass valve which are respectively arranged in parallel, a test sample is placed in the in-pile test device, and the in-pile test device is placed in a neutron field, a second bypass valve is connected in parallel to the heat exchanger, and a heater is clamped on the pipeline.

[0005] Furthermore, it also includes a water chemical unit for adjusting the chemical concentration of water quality in the system, the inlet end of the water chemical unit is connected to the outlet end of the boosting unit, and the outlet end of the water chemical unit is connected to the inlet section of the boosting unit.

[0006] Furthermore, the in-pile test device is connected to the external pile autoclave through a pipeline, a test sample is placed in the external pile autoclave, and the external pile autoclave is placed in a non-neutron field. The in-pile test device and the external pile autoclave are connected in series or in parallel through an adjusting valve. If the in-pile test device and the external pile autoclave are connected in series, the in-pile test device is arranged in front.

[0007] Preferably, second temperature sensors for measuring water temperatures at the inlet and outlet ends of the extra-core autoclave are respectively installed at the inlet and outlet ends of the extra-core autoclave.

[0008] Preferably, a second flow meter for detecting the flow rate flowing through the ex-core autoclave is installed at the inlet end of the ex-core autoclave.

[0009] Furthermore, it also includes a pressure stabilizer for adjusting the system pressure, and the pressure stabilizer is connected to the inlet of the heat exchanger through a surge pipe.

[0010] Furthermore, first temperature sensors for measuring water temperatures at the inlet and outlet ends of the in-pile test device are respectively installed at the inlet and outlet ends of the in-pile test device.

[0011] Furthermore, a first flow meter for detecting the main flow of the system is installed at the inlet end of the in-pile test device.

[0012] The present invention has at least the following advantages and beneficial effects:

[0013] (1) Through the cooperation of the booster unit, the heater and the in-pile test device placed in the neutron field, the medium flowing in the pipeline is radioactive high-temperature and high-pressure water, which can more accurately simulate the in-pile water environment, realize material irradiation tests in high-temperature and high-pressure fields, high-flux neutron fields and radiation fields, improve the reliability of test results, and realize flexible adjustment of system temperature, flow and pressure by adjusting the opening of the first bypass valve and the second bypass valve;

[0014] (2) By setting up a water chemistry unit in parallel with the booster unit, the radioactive water quality conditions and water quality conditions can be flexibly controlled to study the corrosion of materials under different water quality conditions, thereby improving the accuracy and reliability of the test simulation;

[0015] (3) Through the setting of an extra-pile autoclave, the water chemical corrosion test of materials in the extra-pile non-neutron environment and the in-pile neutron environment can be compared, and the switching of different working conditions can be achieved by adjusting the valve to improve the adaptability of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0017] Figure 1 A schematic diagram of an irradiation and water chemical corrosion test system in a high-flux neutron environment provided by the present invention;

[0018] Icons: 1-boosting unit, 11-first boosting pump, 12-second boosting pump, 13-first bypass valve, 14-second bypass valve, 101-first electric stop valve, 102-second electric stop valve, 103-third electric stop valve, 104-fourth electric regulating valve, 111-first manual stop valve, 112-second manual stop valve, 2-in-pile test device, 3-out-of-pile autoclave, 4-heat exchanger, 5-water chemical unit, 6-stabilizer, 71-first temperature sensor, 72-second temperature sensor, 81-first flow meter, 82-second flow meter. DETAILED DESCRIPTION

[0019] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings 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. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0020] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. 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.

[0021] Example

[0022] like Figure 1As shown, in this embodiment, an irradiation and water chemical corrosion test system in a high-flux neutron environment is mainly disclosed, including a booster unit 1, an in-pile test device 2 and a heat exchanger 4. The booster unit 1, the in-pile test device 2 and the heat exchanger 4 are connected end to end through a pipeline to form a closed circulation test loop. The booster unit 1 includes a first booster pump 11, a second booster pump 12 and a first bypass valve 13 arranged in parallel. Specifically, the first booster pump 11 and the second booster pump 12 can both be centrifugal pumps. The cooperation of the pressure pump 12 drives the deionized water in the test loop to circulate in the system pipeline and increase the pressure to provide a high-pressure field environment for the system; the test sample is placed in the in-pile test device 2, and the in-pile test device 2 is placed in the neutron field. Specifically, the in-pile test device 2 can be inserted into the channel of the research reactor with a high-flux neutron field. By adjusting the structure of the in-pile test device 2 or / and replacing different channels for insertion, the relative height of the neutron flux received by the test system can be changed; it should be noted that the test sample and the deionized water are placed in the research reactor with a high-flux neutron field. Flux neutron field activation will generate radioactivity. At the same time, the test sample reacts with neutrons in a neutron irradiation environment to generate hundreds of kilowatts of heat. The heat generated by the test sample can be transferred through the flow of ionized water to prevent the test sample from overheating. It can also be used as an auxiliary heat source to heat the system. In addition, it should be ensured that the in-pile test device 2 is isolated from the pressure and heat of the research reactor, so that the temperature and pressure in the in-pile test device 2 do not affect the temperature and pressure of the research reactor. The heat exchanger 4 is connected in parallel with a second bypass valve 14. The heat exchanger 4 can be a shell and tube heat exchanger 4. The inlet end of the heat exchanger 4 and the second bypass valve 14 are connected to the outlet end of the in-pile test device 2. The outlet end of the heat exchanger 4 and the second bypass valve 14 are connected to the inlet end of the booster unit 1. To avoid system overheating, the heat exchanger 4 can export part of the system heat through secondary water. A heater is sleeved on the pipeline. Specifically, the heater can be a clamp-type electric heater, which is used to heat and insulate the deionized water in the system. The sleeve is fixed at multiple positions of the system pipeline to achieve multi-stage heating, reduce the thermal stress of the pipeline, and ensure the safety of the system.

[0023] It should be noted that this test system is different from the existing γ field irradiation environment where the nuclear heat release of the test material reaction is small. The maximum flow rate of the main pipeline of this test system reaches 12m3 / h, the operating temperature is 340℃, and the pressure reaches 18.6Mpa. It is a material irradiation test circuit with large flow, high temperature, high pressure and high safety requirements under a high-flux neutron environment. Through the booster unit 1, the heater and the in-pile test device 2 placed in the neutron field, a high-temperature and high-pressure operating environment is provided for the test sample. Through the in-pile test device 2 placed in the neutron field, a high-flux neutron field and a radiation field are provided for the test sample, so that the test sample placed in the in-pile test device 2 is tested in the environment of high-temperature and high-pressure field, high-flux neutron field and radiation field at the same time; by adjusting the opening of the first bypass valve 13 and the second bypass valve 14, the system temperature, flow and pressure can be flexibly adjusted.

[0024] Furthermore, in a specific implementation, the embodiment of the present invention further includes a water chemical unit 5 for adjusting the chemical concentration of water quality in the system, the inlet end of the water chemical unit 5 is connected to the outlet end of the boosting unit 1, and the outlet end of the water chemical unit 5 is connected to the inlet section of the boosting unit 1; specifically, the water chemical unit 5 draws out a tributary from the outlet end of the boosting unit 1, and after the temperature and pressure are reduced by the water chemical unit 5 to the set values, the water chemical concentration of the tributary is measured and regulated to control the pH value, conductivity, dissolved hydrogen concentration, dissolved oxygen concentration and other indicators of the tributary, and after the regulated and controlled tributary is heated and pressurized again, it is re-injected into the system loop from the inlet end pipeline of the boosting unit 1 to achieve the goal of controlling the chemical concentration of the main loop, so that the radioactive water quality working conditions and water quality conditions can be flexibly controlled, and different water qualities can be studied. conditions for the corrosion of materials; it should be noted that, on the basis of the material irradiation test loop, a branch of the water chemical unit 5 is added to realize water quality control, which can more accurately simulate the actual working conditions of the material in the reactor and ensure the accuracy of the test; when the system is initially started, deionized water is filled into the system through the water chemical unit 5. After the system is full, the system pressure is again raised to an initial pressure of about 3MPa through the water chemical unit 5; when the system is shut down, the research reactor has been shut down, and the calorific value of the test sample has been reduced to 0, and then the opening of the second bypass valve 14 is reduced, thereby increasing the heat exchange capacity of the heat exchanger 4, reducing the heater power, and reducing the system temperature. At the same time, water is injected into the water chemical unit 5 tank system to keep the system pressure dropping as required. When the system pressure and temperature drop to normal values, the booster unit 1 is shut down.

[0025] Furthermore, in a specific implementation, the in-pile test device 2 provided in the embodiment of the present invention is connected to the out-pile autoclave 3 through a pipeline, and a test sample is also placed in the out-pile autoclave 3, and the out-pile autoclave 3 is placed in a non-neutron field. The in-pile test device 2 and the out-pile autoclave 3 are connected in series or in parallel through an adjusting valve. If the in-pile test device 2 and the out-pile autoclave 3 are connected in series, the in-pile test device 2 is arranged in front; specifically, the out-pile autoclave 3 can be installed in the out-pile process room to ensure that the factor affecting the test in the environment where the out-pile autoclave 3 is located is only the difference in the presence or absence of a high-flux neutron field environment. 3 is connected to the inlet and outlet of the in-pile test device 2 through pipelines in the process room; the high-temperature and high-pressure loop creates a high-temperature and high-pressure water chemical environment (18.6MPa, 340℃) for the out-pile autoclave 3. Since the high-temperature and high-pressure water is in contact with the activation products produced after the test sample is irradiated in the research reactor, the high-temperature and high-pressure water is also radioactive, so that the test sample in the out-pile autoclave 3 is tested in the environment of high-temperature and high-pressure field and radiation field at the same time, realizing the comparison of water chemical corrosion test of materials in the out-pile non-neutron environment and the in-pile neutron environment; in addition, radioactive elements decay, and the high temperature and high pressure flowing through the test sample under different flow paths The radioactivity of the high-temperature and high-pressure water is also different. By adjusting the opening and closing of the valve connecting the off-pile autoclave 3 and the in-pile test device 2, the series-parallel connection mode of the off-pile autoclave 3 and the in-pile test device 2 can be changed; specifically, the second manual stop valve 112 is normally closed. When connected in parallel, the first electric stop valve 101 and the second electric stop valve 102 are in an open state, and the third electric stop valve 103 is in a closed state. The high-temperature and high-pressure water in the pipeline has two flow paths driven by the booster unit 1; one path passes through the first electric stop valve 101, the off-pile autoclave 3, and the heat exchanger 4 in sequence and returns to the booster unit 1; the other path passes through the first electric stop valve 101, the off-pile autoclave 3, and the heat exchanger 4 in sequence and returns to the booster unit 1; The in-pile irradiation test device, the second electric stop valve 102, and the heat exchanger 4 return to the booster unit 1; when connected in series, the first electric stop valve 101 and the second electric stop valve 102 are in a closed state, and the third electric stop valve 103 is in an open state. Driven by the booster unit 1, the high-temperature and high-pressure water in the pipeline flows through the in-pile irradiation test device, the third electric stop valve 103, the off-pile autoclave 3 and the heat exchanger 4 in sequence and returns to the booster unit 1. When connected in series, the in-pile test device 2 is arranged in front, so that the high-temperature and high-pressure water that initially circulates through the off-pile autoclave 3 is already radioactive, ensuring the accuracy and reliability of the control group test.

[0026] Preferably, the inlet and outlet ends of the off-core autoclave 3 are respectively equipped with second temperature sensors 72 for measuring the water temperature at the inlet and outlet ends of the off-core autoclave 3; the inlet end of the off-core autoclave 3 is equipped with a second flow meter 82 for detecting the flow rate flowing through the off-core autoclave 3, that is, by adjusting the third electric stop valve 103 and the fourth electric regulating valve 104, the flow rate of high-temperature and high-pressure water flowing through the off-core autoclave 3 is adjusted.

[0027] Furthermore, in a specific implementation, the embodiment of the present invention also includes a pressurizer 6 for adjusting the system pressure. The pressurizer 6 is connected to the inlet of the heat exchanger 4 through a surge pipe. Specifically, the pressurizer 6 is installed in the hot section of the system. During normal operation, the temperature of the pressurizer 6 is higher than the temperature of the test device by more than 30°C. The upper part of the pressurizer 6 is saturated steam, and the lower part is high-temperature and high-pressure water. By adjusting the steam-water ratio in the pressurizer 6, the pressure of the high-temperature and high-pressure loop is controlled. At the same time, the surge pipe is connected to a first manual stop valve 111 for adjusting the flow of the pressurizer 6.

[0028] Furthermore, in a specific implementation, first temperature sensors 71 for measuring the water temperature of the inlet and outlet ends of the in-pile test device 2 are respectively installed at the inlet and outlet ends of the in-pile test device 2 provided in the embodiment of the present invention; a first flow meter 81 for detecting the main flow of the system is installed at the inlet end of the in-pile test device 2, which is the main flow of the system regulated by adjusting the opening of the first electric stop valve 101, the first bypass valve 13 and the second bypass valve 14; at the same time, the openings of the second electric stop valve 102 (116), the third electric stop valve 103, the fourth electric regulating valve 104, the second bypass valve 14 and the first bypass valve 13 are adjusted according to the test requirements of the test sample so that the flow reaches the required value, thereby realizing comprehensive regulation of the test loop flow.

[0029] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An irradiation and water chemical corrosion test system in a high-flux neutron environment, characterized in that: The invention comprises a booster unit (1), an in-pile test device (2) and a heat exchanger (4) which are connected in sequence by pipelines to form a loop, the booster unit (1) comprises a first booster pump (11), a second booster pump (12) and a first bypass valve (13) which are respectively arranged in parallel, a test sample is placed in the in-pile test device (2), and the in-pile test device (2) is placed in a neutron field, the heat exchanger (4) is connected in parallel with a second bypass valve (14), and a heater is sleeved on the pipeline.

2. The irradiation and water chemical corrosion test system in a high flux neutron environment as claimed in claim 1, characterized in that: It also includes a water chemical unit (5) for adjusting the chemical concentration of water quality in the system, wherein the inlet end of the water chemical unit (5) is connected to the outlet end of the pressurizing unit (1), and the outlet end of the water chemical unit (5) is connected to the inlet section of the pressurizing unit (1).

3. The irradiation and water chemical corrosion test system in a high flux neutron environment as claimed in claim 1, characterized in that: The in-pile test device (2) is connected to an out-pile autoclave (3) via the pipeline, the test sample is placed in the out-pile autoclave (3), and the out-pile autoclave (3) is placed in a non-neutron field. The in-pile test device (2) and the out-pile autoclave (3) are connected in series or in parallel via an adjusting valve. If the in-pile test device (2) and the out-pile autoclave (3) are connected in series, the in-pile test device (2) is arranged in front.

4. The irradiation and water chemical corrosion test system in a high flux neutron environment as claimed in claim 3, characterized in that: Second temperature sensors (72) for measuring water temperatures at the inlet and outlet ends of the off-core autoclave (3) are respectively installed at the inlet and outlet ends of the off-core autoclave (3).

5. The irradiation and water chemical corrosion test system in a high flux neutron environment as claimed in claim 3, characterized in that: A second flow meter (82) for detecting the flow rate flowing through the ex-core autoclave (3) is installed at the inlet end of the ex-core autoclave (3).

6. The irradiation and water chemical corrosion test system in a high flux neutron environment as claimed in claim 1, characterized in that: It also includes a pressure stabilizer (6) for adjusting the system pressure, and the pressure stabilizer (6) is connected to the inlet of the heat exchanger (4) through a surge pipe.

7. The irradiation and water chemical corrosion test system in a high flux neutron environment as claimed in claim 1, characterized in that: The inlet and outlet ends of the in-pile test device (2) are respectively installed with first temperature sensors (71) for measuring the water temperature at the inlet and outlet ends of the in-pile test device (2).

8. The irradiation and water chemical corrosion test system in a high flux neutron environment as claimed in claim 1, characterized in that: A first flow meter (81) for detecting the main flow of the system is installed at the inlet end of the in-pile test device (2).

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