In-reactor corrosion test system

Abstract

The invention relates to the field of research reactor process system design, in particular to an in-reactor corrosion test system which comprises an irradiation device used for irradiating a corrosion test material in a reactor and cooling a corrosion test performed in the reactor based on a sub-cooling system arranged in the irradiation device; the main pump is communicated with the sub-cooling system of the irradiation device through a pipeline and is used for driving a coolant to circularly flow into the sub-cooling system of the irradiation device; the main heat exchanger is arranged on a return pipeline through which the coolant flows from the sub-cooling system of the irradiation device to the main pump, and is used for carrying out heat exchange on the coolant flowing out of the sub-cooling system of the irradiation device; and the pressure stabilizer is arranged on the return pipeline and is used for adjusting the pressure of the return pipeline. According to the device and the method, a corrosion experiment is carried out on an experimental material in an irradiation environment, the water chemical environment requirement of the corrosion experiment can be met, and the accuracy and the reliability of an experimental result are improved.

Description

Technical Field

[0001] The invention relates to the field of research reactor process system design, and in particular to an in-pile corrosion test system. Background Art

[0002] The chemical conditions of reactor coolant water directly affect the corrosion performance of primary circuit structural materials. Therefore, great attention must be paid to the adverse effects of corrosion on primary circuit structural materials, especially the integrity of the fuel cladding.

[0003] As a performance verification platform for fuel elements and material elements, the irradiation test loop consists of multiple subsystems, which can provide real operating conditions in the reactor for fuel elements and material elements. As a reactor safety facility, the irradiation test loop system has strict nuclear safety design standards. The corrosion of materials in the reactor is the result of the combined influence of neutron field, pressure, temperature and water quality conditions (pH value, oxygen, hydrogen, various impurity ions). There are two problems in the current research on corrosion screening of fuel element cladding materials in China: First, the current corrosion screening tests in China are evaluated by off-core autoclave or dynamic water loop tests. Compared with the real in-core environment, the influence of neutron irradiation on the corrosion performance of materials is not considered, and the accuracy and reliability of the test results are insufficient. Second, although the current materials can be subjected to in-core irradiation tests, they can only be carried out in an air environment, which cannot meet the requirements of the high temperature and high pressure water chemical environment of the corrosion test. To reasonably evaluate the irradiation corrosion of materials, it is necessary to conduct tests in an environment simulating the temperature, water environment and irradiation conditions in a light water reactor.

[0004] In summary, the irradiation corrosion test system is the key technology to realize corrosion testing in the in-pile environment. Since the existing corrosion test schemes in China are all conducted outside the pile, and the in-pile nuclear corrosion test has high safety requirements, harsh in-pile environment, small irradiation space, high technical difficulty, and many influencing factors, it is difficult to apply the design of the existing out-of-pile corrosion system. Therefore, China currently does not have the platform and ability to carry out material corrosion testing under in-pile radiation conditions.

[0005] Therefore, there is an urgent need for an in-pile corrosion test system to solve the problem in the prior art that it is impossible to conduct corrosion tests on test materials in an irradiated environment. Summary of the invention

[0006] In view of this, the present invention provides an in-pile corrosion test system, the main purpose of which is to solve the problem in the prior art that it is impossible to perform corrosion tests on test materials in an irradiated environment.

[0007] In order to solve the above problems, the present application provides an in-pile corrosion test system, comprising:

[0008] An irradiation device, used to irradiate the corrosion test materials in the reactor, and based on the sub-cooling system provided in the irradiation device, to cool down the corrosion test conducted in the reactor;

[0009] a main pump, connected to the sub-cooling system of the irradiation device through a pipeline, and used for driving a coolant to circulate and flow into the sub-cooling system of the irradiation device;

[0010] A main heat exchanger is arranged on a return line from the sub-cooling system of the irradiation device to the main pump, and is used to perform heat exchange on the coolant flowing out of the sub-cooling system of the irradiation device;

[0011] A pressure stabilizer is arranged on the return line and is used to adjust the pressure of the return line.

[0012] Optionally, the pressure stabilizer is arranged on the pipeline between the irradiation device and the main heat exchanger.

[0013] Optionally, the in-pile corrosion test system further includes:

[0014] The electric heater is arranged on the delivery pipeline for delivering the coolant from the main pump to the irradiation device, and is used for heating the coolant delivered to the irradiation device.

[0015] Optionally, the main pump comprises a first main pump and a second main pump which are arranged in parallel via a pipeline.

[0016] Optionally, the main heat exchanger is also connected to a secondary cooling water supply subsystem, and the secondary cooling water supply subsystem is used to supply secondary cooling water to the main heat exchanger to perform heat exchange between the secondary cooling water and the coolant.

[0017] Optionally, the secondary cooling water supply subsystem includes two secondary water pumps for driving the secondary cooling water supply, and the two secondary water pumps are arranged in parallel through pipelines.

[0018] Optionally, the in-pile corrosion test system further includes a water chemical subsystem, which is connected in parallel with the main pump via a pipeline, and the water chemical subsystem is used to add coolant or adjust the water quality of the coolant so that the coolant maintains predetermined properties.

[0019] Optionally, the in-pile corrosion test system further includes a nitrogen leak detection subsystem, and the nitrogen leak detection subsystem specifically includes:

[0020] A gas cylinder, storing nitrogen, is connected to the input end of the gas pump through a pipeline and is used to supply nitrogen to the gas pump;

[0021] An air pump, the output end of which is connected to the gas input end of the sealed loop of the irradiation device through a pipeline, and the gas output end of the sealed loop of the irradiation device is connected to the input end of the air pump through a pipeline; the air pump is used to fill the sealed loop with nitrogen;

[0022] A detection device, wherein the detection end is arranged in the sealing loop, is used to detect the sealing performance of the sealing loop.

[0023] Optionally, the coolant is deionized water.

[0024] Optionally, the in-pile corrosion test system further includes a wastewater centralized discharge subsystem, and the wastewater centralized discharge subsystem specifically includes:

[0025] A water tank, connected to a return line between the irradiation device sub-cooling system and the main pump through a first drainage line, for discharging coolant into the water tank; connected to a secondary cooling water supply subsystem through a second drainage line, for discharging secondary cooling water into the water tank;

[0026] The wastewater classification equipment is arranged in the water tank and is used for classifying the wastewater in the water tank to obtain radioactive water, tap water and deionized water.

[0027] The in-pile corrosion test system in the present application realizes corrosion testing of experimental materials in an irradiation environment, and can meet the requirements of the water chemistry environment of the corrosion test, thereby improving the accuracy and reliability of the experimental results, and further can make a reasonable evaluation of the radiation corrosion of the material. It can meet the requirements of the water chemistry environment of the corrosion test, and can be designed to form a comprehensive in-pile irradiation environment corrosion test platform, thereby improving the accuracy and reliability of the experimental results and realizing a reasonable evaluation of the radiation corrosion of the material.

[0028] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention, it can be implemented according to the contents of the specification. In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present invention. Moreover, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:

[0030] Figure 1 A schematic diagram of an in-pile corrosion test system according to an embodiment of the present application;

[0031] Figure 2This is a schematic diagram of an in-pile corrosion testing system according to another embodiment of the present application.

[0032] 1. Irradiation device, 2. Main heat exchanger, 3. Voltage stabilizer, 4. Water chemical subsystem, 5. Main pump, 6. Secondary water pump, 7. Gas cylinder, 8. Gas pump, 9. Electric heater. DETAILED DESCRIPTION

[0033] Various aspects and features of the present application are described herein with reference to the accompanying drawings.

[0034] It should be understood that various modifications may be made to the embodiments of the present application. Therefore, the above description should not be considered as limiting, but only as an example of an embodiment. Other modifications within the scope and spirit of the present application will occur to those skilled in the art.

[0035] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the present application and, together with the general description of the present application given above and the detailed description of the embodiments given below, serve to explain the principles of the present application.

[0036] These and other characteristics of the present application will become apparent from the following description of a preferred form of embodiment given as a non-limiting example with reference to the accompanying drawings.

[0037] It should also be understood that although the present application has been described with reference to some specific examples, those skilled in the art will be able to readily implement many other equivalent forms of the present application.

[0038] The above and other aspects, features and advantages of the present application will become more apparent in view of the following detailed description when taken in conjunction with the accompanying drawings.

[0039] Specific embodiments of the present application are described hereinafter with reference to the accompanying drawings; however, it should be understood that the embodiments applied for are merely examples of the present application, which may be implemented in a variety of ways. Well-known and / or repeated functions and structures are not described in detail to avoid unnecessary or redundant details that obscure the present application. Therefore, the specific structural and functional details applied for herein are not intended to be limiting, but merely serve as a basis and representative basis for the claims to teach those skilled in the art to use the present application in a variety of ways with substantially any suitable detailed structure.

[0040] This specification may use the phrases "in one embodiment," "in another embodiment," "in yet another embodiment," or "in other embodiments," all of which may refer to one or more of the same or different embodiments according to the present application.

[0041] like Figure 1As shown, this embodiment provides an in-pile corrosion test system, which mainly includes: an irradiation device 1, a main heat exchanger 2, a regulator 3, and a main pump 5. The irradiation device 1 is used to irradiate the corrosion test materials in the reactor, and based on the sub-cooling system, cool down the corrosion test conducted in the reactor; the main pump 5 is connected to the sub-cooling system of the irradiation device through a pipeline, and is used to drive the coolant to circulate into the sub-cooling system of the irradiation device; the main heat exchanger 2 is arranged on the return pipeline of the coolant from the irradiation device sub-cooling system to the main pump, and is used to exchange heat with the coolant flowing out of the irradiation device sub-cooling system; the regulator 3 is arranged on the return pipeline, and is used to adjust the pressure of the return pipeline. A heater 9 is also arranged on the delivery pipeline for the coolant from the main pump to the irradiation device, and the electric heater is used to heat the coolant delivered to the irradiation device. In this embodiment, the voltage stabilizer 3 can limit the pressure fluctuation of the circuit within the range of ±0.2MPa by matching the cooling and pressure reduction by spraying and the heating and pressure increase by the electric heating element. In extreme cases, the voltage stabilizer 3 can open its safety valve to transport part of the steam to the pressure relief tank to ensure that the pressure of the circuit does not exceed the limit. In order to ensure the water quality of the circuit, deionized water is used as the main circulation coolant.

[0042] That is to say, the irradiation device 1, the main heat exchanger 2, the voltage regulator 3, the main pump 5 and the heater 9 are connected in sequence through pipelines. The main heat exchanger 2, the voltage regulator 3, the main pump 5 and the electric heater 9 form a high-temperature and high-pressure main cooling water circulation system / main circulation subsystem, the purpose of which is to provide a high-temperature and high-pressure main cooling water circulation system for the irradiation device 1. The main cooling water circulation system is used to realize the thermal hydraulic environment of the corrosion test device. The coolant of the main circulation system is driven by the main pump 5, enters the inlet of the sub-cooling system of the irradiation device after passing through the outlet isolation valve of the main pump 5, and then flows out of the sub-cooling system of the irradiation device through the outlet pipe at the upper end of the test chamber and enters the main heat exchanger 2, transfers heat to the secondary cooling water, and the coolant cooled by the secondary cooling water flows out of the heat exchanger and returns to the inlet of the running main pump 5, thereby forming a circulation of the coolant.

[0043] The in-pile corrosion test system in the present application realizes corrosion testing of experimental materials in an irradiated environment and can meet the water chemical environment requirements of the corrosion test, that is, meet the high temperature and high pressure water chemical environment requirements, improves the accuracy and reliability of the experimental results, and thus can make a reasonable evaluation of the radiation corrosion of the material.

[0044] Based on the above embodiment, another embodiment of the present application provides an in-pile corrosion test system. Figure 2As shown, in this embodiment, the main heat exchanger 2 is also connected to a secondary cooling water supply subsystem, and the secondary cooling water supply subsystem is used to supply secondary cooling water to the main heat exchanger 2 so that the secondary cooling water and the coolant actively exchange heat. The secondary cooling water supply subsystem includes two secondary water pumps 6 for driving the secondary cooling water supply, and the two secondary water pumps 6 are connected in parallel with each other through pipelines.

[0045] In this embodiment, the in-pile corrosion test system also includes a water chemical subsystem 4, which is connected in parallel with the main pump 5 through a pipeline. The water chemical subsystem 4 is used to add coolant or adjust the water quality of the coolant so that the coolant maintains a predetermined property. Specifically, the water chemical subsystem 4 includes: a water chemical regulating device, a pipeline, a valve, etc. The water chemical subsystem 4 is used to maintain or adjust the water chemical environment conditions and the water quality of the coolant of the main circulation system to meet the parameter requirements of the irradiation corrosion test. At the same time, the water chemical subsystem is also provided with a sampling pipeline, which is connected to the pipeline of the main circulation system and is used to collect the coolant in the main circulation system. The other end of the sampling pipe is connected to a predetermined analysis device, which is used to transport the coolant to a predetermined analysis device, so as to analyze the water quality of the coolant in the main circulation system based on the analysis device, and evaluate the influence of different water qualities on the corrosion behavior of the research material. In this embodiment, the water chemical subsystem 4 specifically includes an ion exchange column, a filter and a chemical addition container that are connected in sequence. The water chemical subsystem 4 draws a certain flow from the outlet of the main pump 5, and after cooling through its cooler, it passes through the ion exchange column, filter, chemical addition container and other equipment in turn to remove various impurity ions, suspended particles, adjust the concentration of various ions in the water, and add solution to the water through the chemical dosing device if necessary, or add hydrogen or ammonia to the water through the gas dosing device to make the pH value or dissolved oxygen concentration of the water meet the requirements. The treated cooling water returns to the preheater for heating and then flows back to the inlet of the main pump 5 to complete a purification cycle. In the process of water quality adjustment, in order to measure the water quality of the system, the water chemical subsystem 4 is also provided with a conductivity measuring device, a dissolved oxygen analyzer, a sampling port and other devices. At the same time, the water chemical subsystem 4 also fills the main circuit with water for the first time through its upper filling pump.

[0046] In the specific implementation process of this embodiment, the in-pile corrosion test system also includes a nitrogen leak detection subsystem, which includes an air pump 8, a gas cylinder 7 and a detection device, wherein the detection device specifically includes: any one or more of a thermometer, a hygrometer and a pressure gauge. The gas cylinder 7 stores nitrogen, and the gas cylinder 7 is connected to the input end of the air pump 8 through a pipeline, which is used to supply nitrogen to the air pump 8; the output end of the air pump 8 is connected to the gas input end of the sealing loop of the irradiation device through a pipeline, and the gas output end of the sealing loop of the irradiation device is connected to the input end of the air pump through a pipeline; the detection end of the thermometer, the thermometer, the hygrometer and the pressure gauge is arranged in the sealing loop, which is used to detect the temperature information, humidity information and pressure information of the sealing loop to determine the sealing of the sealing loop. Among them, the sealing loop is the annular gap between the pressure pipe and the insulation pipe in the irradiation device. That is, the air pump 8 fills nitrogen into the annular gap between the pressure tube and the insulation tube in the irradiation device, and continuously circulates the nitrogen in the annular gap, and uses instruments to monitor the temperature, pressure, humidity and other detection parameters of the nitrogen, so as to determine the sealing of the annular gap / sealing loop based on the detection parameters, so as to take protective measures immediately when abnormalities are found.

[0047] In addition, the in-pile corrosion test system in this example also includes the centralized wastewater discharge subsystem, which specifically includes: a water tank, which is connected to the return pipeline between the irradiation device sub-cooling system and the main pump through the first drainage pipeline, and is used to discharge the coolant to the water tank; it is connected to the secondary cooling water supply subsystem through the second drainage pipeline, and is used to discharge the secondary cooling water to the water tank; wastewater classification equipment is arranged in the water tank, and is used to classify the wastewater in the water tank to obtain radioactive water, tap water and deionized water. That is, the centralized wastewater discharge subsystem includes a closed water tank, equipment exhaust and emptying pipelines and valves, and the highest point exhaust and lowest point emptying pipelines and valves of the process pipeline. On the premise of meeting the radiation protection requirements, multiple exhaust pipelines are discharged into a closed water tank, which has three flow channels for radioactive water, tap water and deionized water. This can achieve classified discharge of loop wastewater and reduce the cost of high-level wastewater treatment. Isolation valves are installed near the closed water tank. After all boundary isolation valves are opened, operating personnel can open all remote control valves in the centralized operating area to discharge the system. In addition, the top cover of the water tank is made of transparent organic material, which is convenient for operation and maintenance personnel to observe the emission situation.

[0048] Specifically, the in-pile corrosion test system in this embodiment also includes a supporting electrical instrumentation and control system. The supporting electrical instrumentation and control system is used to ensure the safe operation of the irradiation corrosion system, and performs local control, remote control, manual control, automatic control, water temperature control, pressure control, and electrical parameter collection and display of each device, and transmits the status and parameters of the entire system to the monitoring system. The instrumentation and control system is used to monitor the process parameters of each system of the irradiation corrosion test, mainly including temperature, flow, pressure and water level, etc., and provides necessary monitoring means for the control, operation and safety protection of the test system. Sufficient information is given in the control room for the test personnel to fully understand the operating conditions of each part of the monitoring loop system, and serves as the basis for the normal operation of the control system and the correction of abnormal conditions; process variables are provided for the control and regulation of the system to complete the startup, operation and shutdown of each system.

[0049] The main pump 5, the secondary water pump 6 and the air pump 8 in this embodiment each have two groups, and the two groups are arranged in parallel in the system through pipelines. In maintenance or emergency situations, one group can be closed and the other group can be kept open.

[0050] This test system enables material corrosion tests to be carried out under high temperature and high pressure conditions, while taking into account the comprehensive effects of factors such as neutron field, pressure, temperature and water quality conditions (for example, pH value, oxygen, hydrogen, and various impurity ions) on the material, thus enabling a reasonable evaluation of material irradiation corrosion.

[0051] The in-pile corrosion test system in this embodiment can meet the requirements of corrosion tests in a high-temperature and high-pressure water chemical environment, and can be designed to form a comprehensive in-pile irradiation environment corrosion test platform, thereby improving the accuracy and reliability of the experimental results and making a reasonable evaluation of material radiation corrosion.

[0052] The in-pile corrosion test system in this embodiment establishes an in-pile high-temperature and high-pressure cooling water environment suitable for material irradiation corrosion testing. It realizes the irradiation corrosion test of materials under the in-pile high-temperature and high-pressure cooling water environment, and realizes the material corrosion test research in the water chemistry adjustable environment in the research reactor for the first time in China.

[0053] The water chemistry subsystem includes purification, chemical addition, sampling and analysis and other main functions, which is the key system to achieve the water quality indicators of the in-pile irradiation corrosion test. The design of the centralized wastewater discharge subsystem can realize the classified discharge of loop wastewater and reduce the cost of high-level wastewater treatment. When the system is discharged, the operation and maintenance personnel only need to operate in the centralized operation area, which reduces the difficulty of operating the discharge system and the manpower investment cost.

[0054] The above embodiments are only exemplary embodiments of the present application and are not intended to limit the present application. The protection scope of the present application is defined by the claims. Those skilled in the art may make various modifications or equivalent substitutions to the present application within the essence and protection scope of the present application, and such modifications or equivalent substitutions shall also be deemed to fall within the protection scope of the present application.

Claims

1. An in-pile corrosion test system, characterized in that: include: An irradiation device, used to irradiate the corrosion test materials in the reactor, and based on the sub-cooling system provided in the irradiation device, to cool down the corrosion test conducted in the reactor; a main pump, connected to the sub-cooling system of the irradiation device through a pipeline, and used for driving a coolant to circulate and flow into the sub-cooling system of the irradiation device; A main heat exchanger is arranged on a return line from the sub-cooling system of the irradiation device to the main pump, and is used to perform heat exchange on the coolant flowing out of the sub-cooling system of the irradiation device; A pressure stabilizer is arranged on the return line and is used to adjust the pressure of the return line.

2. The system according to claim 1, characterized in that The pressure stabilizer is arranged on the pipeline between the irradiation device and the main heat exchanger.

3. The system according to claim 1, characterized in that The in-pile corrosion test system also includes: The electric heater is arranged on the delivery pipeline for delivering the coolant from the main pump to the irradiation device, and is used for heating the coolant delivered to the irradiation device.

4. The system according to claim 1, characterized in that The main pump includes a first main pump and a second main pump which are connected in parallel via a pipeline.

5. The system according to claim 1, characterized in that The main heat exchanger is also in communication with a secondary cooling water supply subsystem, and the secondary cooling water supply subsystem is used to supply secondary cooling water to the main heat exchanger so as to perform heat exchange between the secondary cooling water and the coolant.

6. The system according to claim 5, characterized in that The secondary cooling water supply subsystem includes two secondary water pumps for driving the secondary cooling water supply, and the two secondary water pumps are arranged in parallel through pipelines.

7. The system according to claim 1, characterized in that The in-pile corrosion test system also includes a water chemical subsystem, which is connected in parallel with the main pump through a pipeline. The water chemical subsystem is used to add coolant or adjust the water quality of the coolant to keep the coolant in predetermined properties.

8. The system according to any one of claims 1 to 7, characterized in that: The in-pile corrosion test system further includes a nitrogen leak detection subsystem, which specifically includes: A gas cylinder, storing nitrogen, is connected to the input end of the gas pump through a pipeline and is used to supply nitrogen to the gas pump; An air pump, the output end of which is connected to the gas input end of the sealed loop of the irradiation device through a pipeline, and the gas output end of the sealed loop of the irradiation device is connected to the input end of the air pump through a pipeline; the air pump is used to fill the sealed loop with nitrogen; A detection device, wherein the detection end is arranged in the sealing loop, is used to detect the sealing performance of the sealing loop.

9. The system according to any one of claims 1 to 7, characterized in that: The coolant is deionized water.

10. The system according to any one of claims 1 to 7, characterized in that: The in-pile corrosion test system further includes a wastewater centralized discharge subsystem, and the wastewater centralized discharge subsystem specifically includes: A water tank, connected to a return line between the irradiation device sub-cooling system and the main pump through a first drainage line, for discharging coolant into the water tank; connected to a secondary cooling water supply subsystem through a second drainage line, for discharging secondary cooling water into the water tank; The wastewater classification equipment is arranged in the water tank and is used for classifying the wastewater in the water tank to obtain radioactive water, tap water and deionized water.

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