Miniaturized test system for fuel rod in-pile test

Abstract

The invention relates to the technical field of nuclear fuel in-pile testing, in particular to a miniaturized testing system for fuel rod in-pile testing, which comprises an in-pile testing device, a primary water circulation system, a water quality adjusting system, a gas supply system and an emergency water injection system, the primary water circulation system is connected with the in-reactor test device; the water quality adjusting system is connected with the primary water circulation system so as to adjust chemical parameters of water in the primary water circulation system to expected values; the gas supply system is connected with the in-reactor test device so as to introduce a heat insulation medium into the in-reactor test device; and the emergency water injection system is connected with the in-reactor test device so as to introduce cooling water into the in-reactor test device. On the basis of meeting indexes such as temperature, pressure, water chemical environment parameters and flow velocity of the nuclear fuel, the system complexity and the construction cost can be reduced, and the nuclear fuel in-pile testing capability is improved.

Description

Technical Field

[0001] The present application relates to the technical field of nuclear fuel in-pile testing, and in particular to a miniaturized test system for in-pile testing of fuel rods. Background Art

[0002] During the development process of nuclear fuel, its comprehensive performance must be verified through in-pile testing to support safety review and design finalization. Existing technology conducts this through two methods: in-pile testing and loop testing. In-pile testing is easy to implement, but it can only simulate the neutron injection and temperature indicators of nuclear fuel. It cannot simulate indicators such as nuclear fuel pressure, water chemical environmental parameters, and flow rate. It is not representative enough and is only used for exploratory scientific research experiments. Loop testing can achieve the above indicators, but test loop resources are scarce, and the test loop system is complex, the construction cost is high, and the operation and maintenance are difficult. Therefore, due to the limitations of the existing in-pile testing capabilities of nuclear fuel, it is impossible to carry out large-scale in-pile testing of nuclear fuel, which restricts the development process of nuclear fuel. Summary of the Invention

[0003] In response to at least one of the technical problems mentioned in the background technology, this application provides a miniaturized test system for in-pile testing of fuel rods. While meeting the temperature, pressure, water chemical environmental parameters, flow rate and other indicators of nuclear fuel, it reduces system complexity and construction costs and improves the in-pile testing capabilities of nuclear fuel.

[0004] This application is implemented through the following technical solutions: A miniaturized test system for in-pile testing of fuel rods, comprising: In-pile test equipment; a primary water circulation system connected to the in-pile test device; a water quality regulating system connected to the primary water circulation system to regulate chemical parameters of water in the primary water circulation system to expected values; a gas supply system connected to the in-pile test device to supply a thermal insulation medium to the in-pile test device; An emergency water injection system is connected to the in-pile test device to inject cooling water into the in-pile test device.

[0005] In some optional embodiments, the in-pile test device includes: a central component connected to the primary water circulation system and to the emergency water injection system; a connecting section, the connecting section being sleeved on the central component and having one end connected to a flange of the central component, the connecting section being connected to a first through-trachea and a second through-trachea communicating with the interior thereof; an isolation tube, the isolation tube being sleeved on the central component and connected to the flange at the other end of the connecting section; Wherein, the port of the first through-trachea in the connecting section is located at a position flush with an end of the central component away from the connecting section.

[0006] In some optional embodiments, the central component includes: A test section, the test section having an upper support and a lower support arranged at intervals; A fuel rod, one end of which is engaged with the lower support, and the other end of which is engaged with the upper support via a spring.

[0007] In some optional embodiments, the primary water circulation system includes: a heat exchanger connected to the in-pile test device to pass primary water into the in-pile test device or receive primary water from the in-pile test device; a cooler connected to the heat exchanger; a first filter connected to the cooler; A sealed water tank is connected to the first filter and the heat exchanger.

[0008] In some optional embodiments, an ion exchange module is connected between the first filter and the closed water tank.

[0009] In some optional embodiments, a heater is connected between the heat exchanger and the in-pile test device to heat the primary water discharged from the heat exchanger.

[0010] In some optional embodiments, a fuel damage monitoring unit is connected between the cooler and the first filter.

[0011] In some optional embodiments, the water quality regulation system includes: a reagent filling module, the reagent filling module being connected to the primary water circulation system; a gas filling module, the gas filling module being connected to the primary water circulation system; A water quality monitoring unit, which is used to monitor the primary water in the primary water circulation system, wherein the water quality monitoring unit includes one or more of a pH detection module, a conductivity detection module, a calcium ion concentration detection module, a magnesium ion concentration detection module, a silicon ion concentration detection module, a sodium ion concentration detection module, a potassium ion concentration detection module, a lithium ion concentration detection module, and a boron ion concentration detection module.

[0012] In some optional embodiments, the gas supply system includes: High-pressure gas cylinders; a low-pressure gas storage tank connected between the high-pressure gas cylinder and the in-pile test device; A tail gas tank is connected to the in-pile test device.

[0013] In some optional embodiments, the emergency water injection system includes an emergency water injection tank, which is connected to the in-pile test device via two parallel shut-off valve groups.

[0014] Compared with the prior art, this application has the following advantages and beneficial effects: 1. The miniaturized test system for in-pile testing of fuel rods provided in this application has an outer diameter of the in-pile test device that can be controlled within 60 mm. Tests can be carried out in any irradiation channel, which improves the flexibility of the test and expands the scope of application.

[0015] 2. The miniaturized test system for fuel rod in-pile testing provided in this application, through the setting of a primary water circulation system, can utilize the pressure difference from the high pressure of the main pipeline to the low pressure of the closed water tank for filtration and ion exchange, without the need to set up a charging pump, thereby simplifying the equipment configuration; the heat exchanger in the primary water circulation system can realize heat exchange by heating the incoming water and cooling the outgoing water, maximizing the use of the system's own thermal energy, and supplemented by coolant and heater for supplementary regulation, reducing the system's consumption of external energy, saving energy and operating costs.

[0016] 3. The miniaturized test system for in-pile testing of fuel rods provided in this application can supply insulation medium to the in-pile test device through the setting of the gas supply system, thereby achieving thermal insulation between high-temperature components and low-temperature components. At the same time, the parameters of the insulation medium are easy to detect, thereby facilitating the determination of whether the pressure boundary is damaged, thereby ensuring the safety of the research reactor and fuel rods. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the exemplary embodiments of the present application, the following briefly introduces the drawings required for use in the examples. It should be understood that the following drawings only illustrate certain embodiments of the present application and should not be considered as limiting the scope. A person of ordinary skill in the art can also derive other relevant drawings based on these drawings without inventive effort. In the drawings: Figure 1 Schematic diagram of a miniaturized test system for in-pile testing of fuel rods provided in an embodiment of the present application; Figure 2 A schematic diagram of the structure of the in-pile test device provided in an embodiment of the present application; Figure 3 Schematic diagram of the fuel damage monitoring system provided in an embodiment of the present application.

[0018] Markings and corresponding parts names in the accompanying drawings: 1-1. In-pile test device; 1-2. Heat exchanger; 1-3. Cooler; 1-4. Fuel damage monitoring unit; 1-5. First filter; 1-6. Main pipeline check valve; 1-7. Electric valve; 1-8. First ion exchange column; 1-9. Stop valve; 1-10. Electric valve; 1-11. Second ion exchange column; 1-12. Stop valve; 1-13. Electric valve; 1-14. Third ion exchange column; 1-15. Stop valve; 1-16. Second filter; 1-17. First electric stop valve; 1-18. Second electric stop valve; 1-19. Third electric stop valve; 1-20. Fourth electric stop valve; 1-21. First pressure reducing valve; 1-22. Second pressure reducing valve; 1-23. Sealed water tank; 1-24. Stop valve; 1-25. First booster pump; 1-26. Check valve. 1-27, stop valve; 1-28, second booster pump; 1-29, check valve; 1-30, surge tank; 1-31, flow meter; 1-32, flow control valve; 1-33, heater; 1-34, outlet flange; 1-35, inlet flange; 1-1-1, water outlet flange; 1-1-2, water inlet flange; 1-1-3, emergency water inlet; 1-1-4, first through-traffic pipe; 1-1-5, second through-traffic pipe; 1-1-6, isolation pipe; 1-1-7, connecting section; 1-1-8, test section; 1-1-9, water inlet pipe; 1-1-10, water outlet pipe; 1-1-11, first instrument tee; 1-1-12, emergency water injection pipe; 1-1-13, upper cover; 1-1-14, second instrument tee; 1-1-15, second temperature measuring instrument; 1-1-16, second pressure measuring instrument; 1-1-17, first temperature measuring instrument; 1-1-18, first pressure measuring instrument; 1-1-19, neutron fluence measuring instrument; 1-1-20, second temperature measuring instrument probe; 1-1-21, first temperature measuring instrument probe; 1-1-22, neutron fluence measuring instrument probe; 1-1-23, upper support; 1-1-24, spring; 1-1-25, lower support; 1-1-26, center flow channel; 1-1-27, outer annular flow channel; 1-2-1, heat exchanger hot end inlet; 1-2-2, heat exchanger hot end outlet; 1-2-3, heat exchanger cold end inlet; 1-2-4, heat exchanger cold end inlet; 1-4-1, Gamma Detector; 1-4-2, Delayed Neutron Detector; 1-4-3, Nuclide Monitoring Device; 1-4-4, First Electric Valve of Fuel Damage Monitoring Unit; 1-4-5, Second Electric Valve of Fuel Damage Monitoring Unit; 1-4-6, Third Electric Valve of Fuel Damage Monitoring Unit; 1-4-7, Fourth Electric Valve of Fuel Damage Monitoring Unit; 1-4-8, Fifth Electric Valve of Fuel Damage Monitoring Unit; 1-4-9, Sixth Electric Valve of Fuel Damage Monitoring Unit; 1-4-10, Seventh Electric Valve of Fuel Damage Monitoring Unit; 1-23-1, first takeover; 1-23-2, second takeover; 1-23-3, third takeover; 1-23-4, fourth takeover; 1-23-5, fifth takeover; 1-23-6, sixth takeover; 2-1, first isolation valve; 2-2, second isolation valve; 2-3, water quality monitoring unit; 2-4, peristaltic pump; 2-5, peristaltic pump check valve; 2-6, third isolation valve; 2-7, fourth isolation valve; 2-8, first metering pump check valve; 2-9, first metering pump; 2-10, first solvent tank; 2-11, second metering pump check valve; 2-12, second metering pump; 2-13, second solvent tank; 2-14, fifth isolation valve; 2-15, sixth isolation valve; 2-16, high-pressure gas cylinder; 2-17, gas tank inlet electric valve; 2-18, low-pressure gas tank; 2-19, first gas pressure monitoring gauge; 2-20, first safety valve; 2-21, seventh isolation valve; 2-22, eighth isolation valve; 3-1. Inert gas high-pressure cylinder; 3-2. Inert gas storage tank inlet electric valve; 3-3. Inert gas storage tank; 3-4. Second gas pressure monitoring gauge; 3-5. Second safety valve; 3-6. Ninth isolation valve; 3-7. Tenth isolation valve; 3-8. Gas supply system pressure monitoring gauge; 3-9. Gas supply system temperature monitoring gauge; 3-10. Gas supply system humidity monitoring gauge; 3-11. Third safety valve; 3-12. Eleventh isolation valve; 3-13. Twelfth isolation valve; 3-14. Exhaust gas tank; 3-15. Third gas pressure monitoring gauge; 4-1. Emergency water filling tank; 4-2. Fifth electric stop valve; 4-3. Sixth electric stop valve; 4-4. First solenoid valve; 4-5. Second solenoid valve; 4-6. Water tank level monitor. DETAILED DESCRIPTION

[0019] In order to make the objectives, technical solutions and advantages of this application more clear, the present application is further described in detail below in conjunction with examples and drawings. The schematic implementation methods of this application and their descriptions are only used to explain this application and are not intended to limit this application.

[0020] The present application provides a miniaturized test system for fuel rod in-pile testing. Figures 1 to 3 As shown, the miniaturized test system for in-pile testing of fuel rods includes an in-pile test device 1-1, a primary water circulation system, a water quality regulation system, a gas supply system, and an emergency water injection system; the design pressure of the entire system is configured to be 17.2 MPa, the design temperature is configured to be 350°C, and the heat exchange power is configured to be no more than 100 kW.

[0021] The primary water circulation system, gas supply system and emergency water injection system are respectively connected to the in-pile test device 1-1. Among them, the gas supply system mainly introduces insulation medium into the in-pile test device, and the emergency water injection system introduces cooling water into the in-pile test device 1-1. During actual implementation, the water inlet flange 1-1-2 of the in-pile test device 1-1 is connected to the outlet flange 1-34 of the primary water circulation system, and the water outlet flange 1-1-1 of the in-pile test device 1-1 is connected to the inlet flange 1-35 of the primary water circulation system, forming a closed circulation loop. The heat released by the fuel rods in the in-pile test device 1-1 is taken away by the primary water circulation. The circulation method can be that the primary water first passes through the annular gap flow channel 1-1-27 outside the in-pile test device 1-1, reverses at the bottom of the in-pile test device 1-1 and enters the central flow channel 1-1-26 of the in-pile test device 1-1, and then flows to the water outlet of the in-pile test device 1-1 after being heated by the fuel rods in the central flow channel 1-1-26.

[0022] The water quality regulating system is connected to the closed water tank 1-23 of the primary water circulation system. The water quality regulating system can monitor the chemical parameters of the water in the closed water tank 1-23 and adjust the water quality by adding corresponding chemical reagents and gases according to the monitoring results. Therefore, the water quality regulating system may include a monitoring module and a regulating module. The regulating module controls the flow rate, flow rate, pressure, etc. of the chemical reagents and gases according to the monitoring results of the monitoring module; the water inlet of the monitoring module in the water quality regulating system is connected to the second connecting pipe 1-23-2 of the closed water tank 1-23 of the primary water circulation system, and the return water port is connected to a The secondary water circulation system's enclosed water tank 1-23 is connected to a third connecting pipe 1-23-3, forming a circulation monitoring loop for continuous online monitoring of water chemical parameters. The water quality regulation system's regulation modules include a first reagent filling module, a second reagent filling module, and a gas filling module. The outlets of the first and second reagent filling modules are connected to a fourth connecting pipe 1-23-4 of the primary water circulation system's water tank to form a liquid chemical reagent filling branch. The outlet of the gas filling module is connected to a fifth connecting pipe 1-23-5 of the primary water circulation system's water tank to form a gas filling branch. The gas supply system includes a gas source branch and an exhaust branch. The gas source branch is connected to a first through-gas pipe 1-1-4 of the in-pile test device, and the exhaust branch is connected to a second through-gas pipe 1-1-4 of the in-pile test device. The emergency water injection system is connected to the emergency water injection port 1-1-3 of the in-pile test device 1-1. The water tank 4-1 of the emergency water injection system is located higher than the emergency water injection port 1-1-3, so that the emergency water injection system can adopt gravity flow to reduce the setting of injection pumps and high-pressure gas cylinders in the traditional high-temperature and high-pressure circuit, and optimize the system setting.

[0023] In some optional embodiments, the in-pile test device 1-1 includes an isolation tube 1-1-6, a connecting section 1-1-7 and a central assembly; in the working state, the isolation tube 1-1-6 is sealed with the flange hole on the top of the research reactor to ensure the integrity of the pressure boundary of the research reactor and to achieve isolation of the in-pile test device 1-1 from the research reactor; the lower end flange of the connecting section 1-1-7 is sealed with the upper end flange of the isolation tube 1-1-6, and the upper end flange of the connecting section 1-1-7 is sealed with the flange of the central assembly. The aforementioned sealed connection can be achieved by, for example, providing a sealing ring to ensure good sealing inside the in-pile test device 1-1; a first through hole and a second through hole are provided on the connecting section 1-1-7, and the first through gas pipe 1-1-4 passes through The first through hole penetrates the connecting section 1-1-7 and extends to the bottom of the in-pile test device 1-1, which means that the end of the first through-gas pipe 1-1-4 in the in-pile test device 1-1 is flush with the lower end of the central component, and the second through-gas pipe 1-1-5 penetrates the wall of the connecting section 1-1-7 through the second through hole, thereby forming an air path for intake and exhaust, ensuring that the pure gas source gas supplied by the gas supply system can completely replace the existing gas inside the in-pile test device 1-1; the central component may specifically include the test section 1-1-8, the water inlet pipe 1-1-9, the water outlet pipe 1-1-10, the emergency water injection pipe 1-1-12, the upper cover 1-1-13, the first instrument tee 1-1-11, the second instrument tee 1-1- 14. First temperature measuring instrument 1-1-17, second temperature measuring instrument 1-1-15, first pressure measuring instrument 1-1-18, second pressure measuring instrument 1-1-16 and neutron flux measuring instrument 1-1-19; test section 1-1-8 is connected to upper cover 1-1-13 through water inlet pipe 1-1-9, water outlet pipe 1-1-10 and emergency water injection pipe 1-1-12 to facilitate overall installation and disassembly; first instrument tee 1-1-11 and second instrument tee 1-1-14 are respectively connected to the top of water inlet pipe 1-1-9 and water outlet pipe 1-1-10 to form an instrument lead channel; first temperature measuring instrument 1-1-17 is installed at the bottom inside water inlet pipe 1-1-9, and the lead runs along the water inlet pipe The inner wall of 1-1-9 passes through the first instrument tee 1-1-11. The second temperature measuring instrument 1-1-15 is installed at the bottom of the outlet pipe 1-1-10. The lead wire passes through the second instrument tee 1-1-14 along the inner wall of the outlet pipe. The pressure lead pipe of the first pressure measuring instrument 1-1-18 is directly connected to the first instrument tee 1-1-11. The pressure lead pipe of the second pressure measuring instrument 1-1-16 is directly connected to the second instrument tee 1-1-14. The neutron fluence measuring instrument 1-1-19 is installed near the middle of the inner wall of the annular gap flow channel outside the in-core test device 1-1 to make the monitoring value more representative. The lead wire of the neutron fluence measuring instrument 1-1-19 passes through the first instrument tee 1-1-11 along the inlet pipe.The fuel rods are arranged between the lower support 1-1-25 and the upper support 1-1-24 of the test section 1-1-8. The fuel rods are connected to the upper support 1-1-24 via a spring 1-1-23, which presses the fuel rods against the lower support 1-1-25, thereby achieving positioning and pre-tightening of the fuel rods. The first temperature measuring instrument 1-1-17, the second temperature measuring instrument 1-1-15, the first pressure measuring instrument 1-1-18, the second pressure measuring instrument 1-1-16, and the neutron fluence measuring instrument 1-1-19 of the central assembly respectively implement the functions of online measurement of temperature, pressure, and neutron fluence. During the test, the fuel rods operate at a high temperature, causing the central assembly to also be at a high temperature. The insulating medium, typically an inert gas, introduced from the gas supply system through the first through-gas pipe 1-1-4 can achieve thermal insulation for the central assembly and prevent heat from being discharged from the isolation tube into the cooling water of the research reactor, thereby affecting the thermal characteristics of the research reactor.

[0024] Compared with traditional loops, the outer diameter of the in-pile test devices therein is more than 100 mm, and tests can only be carried out in a few large-sized channels, which limits the application conditions of the tests. In the miniaturized test system for in-pile testing of fuel rods provided in the embodiment of the present application, the in-pile test device is miniaturized, and the outer diameter is allowed to be configured within 60 mm. Tests can be carried out in any irradiation channel, which improves the flexibility of the test and expands the scope of application.

[0025] In some optional embodiments, the primary water circulation system may specifically include an inlet flange 1-35, a heat exchanger 1-2, a cooler 1-3, a fuel damage monitoring unit 1-4, a first filter 1-5, a main pipeline check valve 1-6, a first ion exchange column module, a second ion exchange column module, a third ion exchange column module, a second filter 1-16, a first electric stop valve 1-17, a second electric stop valve 1-18, a third electric stop valve 1-19, a fourth electric stop valve 1-20, a first pressure reducing valve 1-21, a second pressure reducing valve 1-22, a closed water tank 1-23, a first booster pump module, a second booster pump module, a flow regulating valve 1-32, a pressure stabilizing tank 1-30, a flow meter 1-31, a heating The heat exchanger 1-2 is connected to the water outlet flange 1-1-1 and the water inlet flange 1-1-2 of the in-pile test device 1-1 through the inlet flange 1-35 and the outlet flange 1-34, respectively. The outlet flange 1-34 is connected to the heat exchanger 1-2 through the heater 1-33 to heat the water flowing out of the heat exchanger 1-2. The cooler 1-3 is connected to the heat exchanger 1-2. The cooler 1-3, the fuel damage detection unit 1-4, the first filter 1-5, the main pipeline check valve 1-6, the first electric stop valve 1-17, the third electric stop valve 1-19, and the first pressure reducing valve 1-21 are connected in sequence. The first electric stop valve 1-17 is connected to the first ion exchange column module , the second ion exchange column module, and the third ion exchange column module are connected in parallel. After the first ion exchange column module, the second ion exchange column module, and the third ion exchange column module are connected in parallel, they are connected to one end of the first electric stop valve 1-17 through the second filter 1-16. The first electric stop valve 1-17 and the second electric stop valve 1-18 are connected in parallel to form a first parallel valve group. The third electric stop valve 1-19 is connected in series with the first pressure reducing valve 1-21, and the fourth electric stop valve 1-20 is connected in series with the second pressure reducing valve 1-22. The series branch composed of the third electric stop valve 1-19 and the first pressure reducing valve 1-21 and the series branch composed of the fourth electric stop valve 1-20 and the second pressure reducing valve 1-22 are connected in parallel to form a second parallel valve group. The first parallel valve group and the second parallel valve group are connected in series. The reliability of the main branch flow channel is ensured by the first parallel valve group and the second parallel valve group. Even if a valve fails to open normally, the other branch can still operate normally. The series connection between the first parallel valve group and the second parallel valve group ensures that there are two isolation valves on the high-pressure side and the low-pressure side of the main pipeline, ensuring the reliability of the pressure boundary. The first pressure reducing valve 1-21 is connected to the first connecting pipe 1-23-1 on the closed water tank 1-23. The first booster pump module may include a stop valve 1-24, a first booster pump 1-25 and a check valve 1-26. The second booster pump module may include a stop valve 1-27, a second booster pump 1-28 and a check valve 1-29.The sixth connecting pipe 1-23-6 of the closed water tank 1-23 is connected to the stop valve 1-24 and the stop valve 1-27 respectively, wherein the stop valve 1-27 is connected to the second boosting pump 1-28, the check valve 1-29 and the flow meter 1-31 in sequence and then connected to the cold end inlet 1-2-3 of the heat exchanger, the stop valve 1-24 is connected to the first boosting pump 1-25, the check valve 1-26 and the flow meter 1-31 in sequence and then connected to the cold end inlet 1-2-3 of the heat exchanger, and the outlet sides of the check valve 1-26 and the check valve 1-29 are connected to the pressure stabilizing tank 1-30. One end of the outlet flange 1-34 is connected to the water inlet flange 1-1-2 of the in-pile test device 1-1, and the other end is connected to the hot end water inlet 1-2-1 of the heat exchanger. After the primary water is cooled in the heat exchanger 1-2 for the first stage, it is discharged from the hot end water outlet 1-2-2 of the heat exchanger and then enters the cooler 1-3 for the second cooling. After the temperature is reduced to the target temperature by adjusting the cooling water flow on the secondary side of the cooler 1-3, fuel damage monitoring is performed in the fuel damage monitoring unit 1-4, and then the water is sent to the first filter 1-5 for filtration to remove suspended matter and solid impurities. According to the water quality, if it is necessary to put in an ion exchange column module, the first electric stop valve 1-17 and the second electric stop valve 1-18 are closed, and one or more of the first ion exchange column module, the second ion exchange column module, and the third ion exchange column module are opened. After the ion exchange column module is put in, it returns to the main line through the second filter 1-16. If it is not necessary to put in The water entering the ion exchange column module is directly discharged through the first electric stop valve 1-17 and the second electric stop valve 1-18, then passes through the third electric stop valve 1-19, the fourth electric stop valve 1-20, the first pressure reducing valve 1-21, and the second pressure reducing valve 1-22 into the sealed water tank 1-23. The water quality adjustment system adds reagents or injects gas based on the monitoring results to adjust the water quality parameters of the sealed water tank 1-23 to meet the test water quality requirements. The first booster pump module / the second booster pump module then delivers the water in the sealed water tank 1-23 at a specific flow rate to the cold-end water inlet 1-2-3 of the heat exchanger. After the first stage of heating in the heat exchanger 1-2, the water is discharged from the cold-end water outlet 1-2-4 of the heat exchanger and enters the heater 1-33 for a second stage of heating. After the temperature reaches the test temperature by adjusting the power of the heater 1-33, the water enters the in-pile test device 1-1 through the outlet flange 1-34.

[0026] In the embodiment of the present application, control indicators such as test pressure, flow rate, and temperature are realized in the system; the functions of the main cooling system, purification system, and detection system of the traditional high-temperature and high-pressure circuit are organically combined, which simplifies the system workflow and reduces the complexity of the system; the pressure difference from the high pressure of the main pipeline to the low pressure of the closed water tank is fully utilized for filtration and ion exchange, and there is no need to set up a charging pump, which simplifies the equipment configuration; and the heat exchanger 1-2 is used to heat the incoming water and cool the outgoing water for the first heat exchange, which can maximize the use of the system's own thermal energy, and then supplemented by the coolant and heater 1-33 for supplementary adjustment, reducing the system's consumption of external energy and saving energy and operating costs.

[0027] In some optional embodiments, the fuel damage monitoring unit may specifically include one or more of a gamma detection device 1-4-1, a delayed neutron detection device 1-4-2, and a nuclide monitoring device 1-4-3. When the outlet water temperature of the cooler 1-3 exceeds the operating temperature range of the fuel damage monitoring unit, the first electric valve 1-4-4 of the fuel damage monitoring unit is opened, and the second electric valve 1-4-5, the third electric valve 1-4-6, the fourth electric valve 1-4-7, the fifth electric valve 1-4-8, the sixth electric valve 1-4-9, and the seventh electric valve 1-4-10 of the fuel damage monitoring unit are closed; when the cooler 1-3 When the outlet water temperature meets the fuel damage monitoring unit's operating temperature range, the first electric valve 1-4-4 of the fuel damage monitoring unit is closed, and the second electric valve 1-4-5, third electric valve 1-4-6, fourth electric valve 1-4-7, fifth electric valve 1-4-8, sixth electric valve 1-4-9, and seventh electric valve 1-4-10 of the fuel damage monitoring unit are opened to release primary water to each monitoring unit. This fuel damage monitoring unit utilizes a combination of methods to implement fuel damage monitoring, increasing the diversity of monitoring and ensuring the reliability of monitoring results.

[0028] In some optional embodiments, the first ion exchange column module may specifically include an electric valve 1-7, a first ion exchange column 1-8, and a shut-off valve 1-9; the second ion exchange column module may specifically include an electric valve 1-10, a second ion exchange column 1-11, and a shut-off valve 1-12; and the third ion exchange column module may specifically include an electric valve 1-13, a third ion exchange column 1-14, and a shut-off valve 1-15. The input method is to close the first electric shut-off valve 1-17 and the second electric shut-off valve 1-18 on the main line and open the electric valve 1-7, the electric valve 1-10, and the electric valve 1-13. The electric valve 1-7, the electric valve 1-10, and the electric valve 1-13 have a temperature interlock protection function. When the water temperature at the cooler outlet exceeds the temperature range of the first ion exchange column 1-8, the second ion exchange column 1-11, and the third ion exchange column 1-14, the electric valve 1-7, the electric valve 1-10, and the electric valve 1-13 are not allowed to open. The exchange resins in the first ion exchange column 1-8, the second ion exchange column 1-11, and the third ion exchange column 1-14 can be an anion exchange resin, an anion and cation exchange resin, or a mixed ion exchange resin.

[0029] In some optional embodiments, the first booster pump 1-25 and the second booster pump 1-28 use naturally cooled plunger pumps. The two plunger pumps are powered by two different low-voltage power supplies. At the same time, both plunger pumps are connected to a UPS reliable power supply. During operation, one is put into use and the other is used as a backup. The pump outlet is connected to a flow meter 1-31. The flow rate entering the heat exchanger 1-2 can be controlled by the flow regulating valve 1-32 of the pump outlet return line. The excess flow at the pump outlet is returned to the closed water tank through the first pressure reducing valve 1-21 or the second pressure reducing valve 1-22. Compared with the traditional high-temperature and high-pressure circuit main pump, the naturally cooled plunger pump does not require an additional main pump cooling water source, which simplifies the system setting. At the same time, the excess flow of the pump is returned to the closed water tank 1-23 by the system's pressure reducing valve, eliminating the need to set up a dedicated return line, further simplifying the system.

[0030] The water quality regulating system is used to monitor and regulate the water quality in the closed water tank 1-23 online to achieve the water quality parameters required by the test. In some optional embodiments, the monitoring module of the water quality regulating system may specifically include a first isolation valve 2-1, a second isolation valve 2-2, a water quality monitoring unit 2-3, a peristaltic pump 2-4, a peristaltic pump check valve 2-5, a third isolation valve 2-6 and a fourth isolation valve 2-7; the water quality monitoring unit 2-3 may further include a pH value monitoring module, a conductivity monitoring module, a calcium ion concentration monitoring module, a magnesium ion concentration monitoring module, a silicon ion concentration monitoring module, a sodium ion concentration monitoring module, a potassium ion concentration monitoring module, a lithium ion concentration monitoring module, and a water quality monitoring module. The concentration monitoring module, one or more measuring instruments in the boron ion concentration monitoring module, the second connecting pipe 1-23-2 on the closed water tank 1-23 is connected in sequence with the first isolation valve 2-1, the second isolation valve 2-2, the water quality monitoring unit 2-3, the peristaltic pump 2-4, the peristaltic pump check valve 2-5, the third isolation valve 2-6 and the fourth isolation valve 2-7, and then connected to the third connecting pipe 1-23-3 on the closed water tank 1-23; the first reagent filling module includes the first solvent tank 2-10, the first metering pump 2-9, the first metering pump check valve The first and second reagent filling modules are connected to the fourth connecting pipe 1-23-4 of the sealed water tank through the fifth isolation valve 2-14 and the sixth isolation valve 2-15. The gas filling module of the water quality regulation system can specifically include a high-pressure gas cylinder 2-16 and a low-pressure gas storage tank 2-18. , gas tank air inlet electric valve 2-17, first gas pressure monitoring gauge 2-19, first safety valve 2-20, seventh isolation valve 2-21 and eighth isolation valve 2-22, high-pressure gas cylinder 2-16, gas tank air inlet electric valve 2-17, low-pressure gas tank 2-18, seventh isolation valve 2-21 and eighth isolation valve 2-22 are connected in sequence and connected to the fifth connecting pipe 1-23-5 on the closed water tank 1-23, and the low-pressure gas tank 2-18 is equipped with a first gas pressure monitoring gauge 2-19 and a first safety valve 2-20.

[0031] The gas supply system is used to provide inert gas to the in-pile test device 1-1 to achieve thermal insulation between high-temperature components and low-temperature components, and at the same time monitor the gas parameters inside the in-pile test device 1-1 to determine whether the pressure boundary is damaged. In some optional embodiments, the gas supply system includes a gas source branch and an exhaust branch, the gas source branch includes an inert gas high-pressure cylinder 3-1, an inert gas storage tank 3-3, an inert gas storage tank air inlet electric valve 3-2, a second gas pressure monitoring gauge 3-4, a second safety valve 3-5, a ninth isolation valve 3-6 and a tenth isolation valve 3-7, the inert gas high-pressure cylinder 3-1, the inert gas storage tank air inlet electric valve 3-2, the inert gas storage tank 3-3, the ninth isolation valve 3-6 and the tenth isolation valve 3-7 are sequentially connected and connected to the in-pile test device 1-1, the second gas pressure monitoring gauge 3-4 and the second safety valve 3-5 are arranged on the inert gas storage tank 3-3; the exhaust branch may specifically include a tail gas tank 3-14, a third gas pressure monitoring gauge 3-15, a third safety valve 3-11, an eleventh isolation valve 3-12, a twelfth isolation valve 3-13, a gas supply system pressure monitoring gauge 3-8, The gas supply system temperature monitoring meter 3-9, the gas supply system humidity monitoring meter 3-10, the eleventh isolation valve 3-12, and the twelfth isolation valve 3-13 are connected in sequence and then connected to the tail gas tank 3-14. Among them, the eleventh isolation valve 3-12 is connected to the in-core test device 1-1. The gas supply system pressure monitoring meter 3-8, the gas supply system temperature monitoring meter 3-9, and the gas supply system humidity monitoring meter 3-10 are configured on the gas passage between the eleventh isolation valve 3-12 and the in-core test device 1-1. The third safety valve 3-11 is configured between the tail gas tank 3-14 and the in-core test device 1-1, and the third gas pressure monitoring meter 3-15 is configured on the tail gas tank 3-14. During operation, if the pressure, temperature, humidity, etc. exceed the standard, it indicates that the isolation pipe 1-1-6 of the in-core test device 1-1 or the pressure boundary of the high-temperature water has leaked, and the test needs to be stopped immediately to ensure the safety of the research reactor and fuel rods.

[0032] The emergency water injection system provides cooling water to the annular flow channel of the test section in the event of a breach in the in-pile test device 1-1 or the primary water circulation system. In some optional embodiments, the emergency water injection system may specifically include an emergency water injection tank 4-1, a fifth electric shut-off valve 4-2, a sixth electric shut-off valve 4-3, a first solenoid valve 4-4, and a second solenoid valve 4-5. The fifth electric shut-off valve 4-2 and the sixth electric shut-off valve 4-3 are connected in series to form a first water injection channel, and the first solenoid valve 4-4 and the second solenoid valve 4-5 are connected in series to form a second water injection channel. The first and second water injection channels are connected in parallel. The emergency water injection tank 4-1 is equipped with a water tank level monitor 4-6. Each water injection channel is isolated by a double valve, ensuring the integrity of the pressure boundary of the in-pile high-pressure section. The use of two water injection channels with different valve types also effectively prevents conjugate failures of the equipment, ensuring the reliability of the emergency cooling water for the in-pile test device. The fifth electric shut-off valve 4-2, the sixth electric shut-off valve 4-3, the first solenoid valve 4-4, and the second solenoid valve 4-5 are interlocked with the first pressure measuring instrument 1-1-18 and the second pressure measuring instrument 1-1-16 of the in-pile test apparatus 1-1. When the signals of the first pressure measuring instrument 1-1-18 and the second pressure measuring instrument 1-1-16 simultaneously decrease to specific values, the fifth electric shut-off valve 4-2, the sixth electric shut-off valve 4-3, the first solenoid valve 4-4, and the second solenoid valve 4-5 are fully opened, and water is injected into the annular gap flow channel 1-1-27 of the test section 1-1-8 until the fuel rods are submerged. This embodiment of the present application utilizes gravity flow to reduce the need for traditional high-temperature and high-pressure circuit injection pumps and high-pressure gas cylinders, optimizing system configuration. Furthermore, through the conservative design of the emergency water tank capacity, an adequate supply of emergency cooling water is ensured, safeguarding the safety of the fuel rods.

[0033] In some optional embodiments, the in-pile test device 1-1, the primary water circulation system, the emergency water injection system, and the pipes and valves used in the system are configured to the nuclear safety level, the water quality regulation system and the inert gas system are configured to the non-nuclear safety level, and at least two valves are used to isolate different safety levels.

[0034] The above is an explanation of the implementation mode of the present application by specific specific embodiments. Those skilled in the art can easily understand other advantages and effects of the present application from the contents disclosed in this specification. Although the description of the present application will be introduced in conjunction with some embodiments, this does not mean that the features of this application are limited to the implementation mode. On the contrary, the purpose of introducing the application in conjunction with the implementation mode is to cover other options or modifications that may be extended based on the claims of the present application. In order to provide an in-depth understanding of the present application, the above description contains many specific details. The present application can also be implemented without using these details. In addition, in order to avoid confusion or blurring the focus of the present application, some specific details will be omitted in the description. It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other unless there is a conflict.

[0035] It should be noted that in this specification, similar numbers and letters represent similar items in the above figures. Therefore, once an item is defined in one figure, it does not need to be further defined or explained in subsequent figures. In the description of this application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the figures. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, they should not be understood as limiting this application. In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance. In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "mounted", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, an indirect connection through an intermediate medium, or it can be a communication between two elements. For those skilled in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0036] Obviously, those skilled in the art may make various changes and modifications to this application without departing from the spirit and scope of this application. Thus, if these modifications and variations of this application fall within the scope of the claims of this application and their equivalents, this application is intended to include these modifications and variations.

Claims

1. A miniaturized test system for in-pile testing of fuel rods, characterized in that: include: In-pile test device (1-1); a primary water circulation system connected to the in-pile test device (1-1); a water quality regulating system connected to the primary water circulation system to regulate chemical parameters of water in the primary water circulation system to expected values; a gas supply system connected to the in-pile test device (1-1) to pass a heat-insulating medium into the in-pile test device (1-1); An emergency water injection system is connected to the in-pile test device (1-1) to introduce cooling water into the in-pile test device (1-1).

2. The miniaturized test system for fuel rod in-pile testing according to claim 1, characterized in that: The in-pile test device (1-1) comprises: a central component connected to the primary water circulation system and to the emergency water injection system; a connecting section (1-1-7), the connecting section (1-1-7) being sleeved on the central component and having one end thereof flange-connected to the central component; the connecting section (1-1-7) being connected to a first through-trachea (1-1-4) and a second through-trachea (1-1-5) communicating with the interior thereof; an isolation tube (1-1-6), the isolation tube (1-1-6) being sleeved on the central component and flange-connected to the other end of the connecting section (1-1-7); The port of the first through-trachea (1-1-4) in the connecting section (1-1-7) is located flush with an end of the central component away from the connecting section (1-1-7).

3. The miniaturized test system for fuel rod in-pile testing according to claim 2, characterized in that: The central components include: A test section (1-1-8), wherein the test section (1-1-8) has an upper support (1-1-23) and a lower support (1-1-25) arranged at intervals; A fuel rod, one end of which cooperates with the lower support (1-1-25), and the other end of which cooperates with the upper support (1-1-23) via a spring (1-1-24).

4. The miniaturized test system for fuel rod in-pile testing according to claim 1, characterized in that: The primary water circulation system comprises: a heat exchanger (1-2), the heat exchanger (1-2) being connected to the in-pile test device (1-1) to pass primary water into the in-pile test device (1-1) or to receive primary water from the in-pile test device (1-1); A cooler (1-3), the cooler (1-3) being connected to the heat exchanger (1-2); a first filter (1-5), the first filter (1-5) being connected to the cooler (1-3); A sealed water tank (1-23), the sealed water tank (1-23) is connected to the first filter (1-5) and to the heat exchanger (1-2).

5. The miniaturized test system for fuel rod in-pile testing according to claim 4, characterized in that: An ion exchange module is connected between the first filter (1-5) and the sealed water tank (1-23).

6. The miniaturized test system for fuel rod in-pile testing according to claim 4, characterized in that: A heater (1-33) is connected between the heat exchanger (1-2) and the in-pile test device (1-1) to heat the primary water discharged from the heat exchanger (1-2).

7. The miniaturized test system for fuel rod in-pile testing according to claim 4, characterized in that: A fuel damage monitoring unit (1-4) is connected between the cooler (1-3) and the first filter (1-5).

8. The miniaturized test system for fuel rod in-pile testing according to claim 1, characterized in that: The water quality regulation system comprises: a reagent filling module, the reagent filling module being connected to the primary water circulation system; a gas filling module, the gas filling module being connected to the primary water circulation system; A water quality monitoring unit (2-3) is used to monitor primary water in a primary water circulation system, wherein the water quality monitoring unit (2-3) includes one or more of a pH detection module, a conductivity detection module, a calcium ion concentration detection module, a magnesium ion concentration detection module, a silicon ion concentration detection module, a sodium ion concentration detection module, a potassium ion concentration detection module, a lithium ion concentration detection module, and a boron ion concentration detection module.

9. The miniaturized test system for fuel rod in-pile testing according to claim 1, characterized in that: The gas supply system comprises: High-pressure gas cylinders (2-16); a low-pressure gas storage tank (2-18), the low-pressure gas storage tank (2-18) being connected between the high-pressure gas cylinder (2-16) and the in-pile test device (1-1); An exhaust gas tank (3-14) is connected to the in-pile test device (1-1).

10. The miniaturized test system for fuel rod in-pile testing according to claim 1, characterized in that: The emergency water injection system comprises an emergency water injection tank (4-1), and the emergency water injection tank (4-1) is connected to the in-pile test device (1-1) via two parallel shut-off valve groups.

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