Debugging method for main steam pipeline system of sodium-cooled fast reactor

Abstract

The application discloses a kind of sodium-cooled fast reactor main steam pipeline system debugging method, comprising the following steps: according to sodium-cooled fast reactor main steam pipeline system function, sodium-cooled fast reactor main steam pipeline system needs to be screened out and is debugged equipment;According to the equipment needing to be debugged of sodium-cooled fast reactor main steam pipeline system, the performance of equipment is analyzed, determines the debugging test item and content that each equipment should execute;Determine the debugging technical requirement and order of the debugging test item that each equipment should execute.The sodium-cooled fast reactor main steam pipeline system debugging method, by analyzing the design characteristics of sodium-cooled fast reactor main steam pipeline system and the actual demand of system debugging work execution, the debugging technical requirement of this system is described in detail, the adoption of this debugging technical requirement will be able to fully, efficiently verify the function of sodium-cooled fast reactor main steam pipeline system, to ensure that sodium-cooled fast reactor main steam pipeline system fully play system function when sodium water accident occurs provides strong guarantee.

Description

Technical Field

[0001] This invention belongs to the field of nuclear energy technology, specifically relating to a commissioning method for the main steam pipeline system of a sodium-cooled fast reactor. Background Technology

[0002] The CFR600 demonstration fast reactor is a sodium-cooled fast neutron breeder reactor, one of the first units built in the fourth generation of nuclear power technology.

[0003] Unlike current pressurized water reactors, the demonstration fast reactor is a pool-type sodium-cooled fast neutron reactor with a sodium-sodium-water / steam triple loop system for primary heat transfer. Each loop of the triple loop in the demonstration fast reactor has eight once-through steam generator modules, each consisting of one steam generator and one superheater. When a heat transfer tube rupture accident occurs in the steam generator of the sodium-cooled fast reactor, water in the triple loop leaks into the liquid sodium in the secondary loop, triggering a sodium-water reaction. This produces a large amount of hydrogen gas within the affected steam generator, altering the heat transfer efficiency of the reactor's secondary loop and potentially leading to a rise in core temperature. This type of heat transfer tube rupture accident in the steam generator of a sodium-cooled fast reactor is one of the most critical considerations in the design and operation of sodium-cooled fast reactors. After a sodium-water reaction occurs due to a leak in the steam generator's heat transfer tube, the main steam pipeline system of the fast reactor assumes the functions of primary steam isolation and subsequent venting.

[0004] like Figure 1 As shown, the sodium-cooled fast reactor three-loop system includes: generator 1, turbine 2, condenser 3, deaerator 4, bypass valve 5, main feedwater pump 6, steam generator 7, and superheater 8. Generator 1 is connected to turbine 2. Turbine 2 is connected to superheater 8, deaerator 4, and condenser 3 respectively. Superheater 8 is connected to steam generator 7. Steam generator 7 is connected to main feedwater pump 6. Main feedwater pump 6 is connected to deaerator 4 and condenser 3 respectively. Condenser 3 is connected to the second pipeline between turbine 2 and superheater 8 through a first pipeline. A bypass valve 5 is installed on the first pipeline.

[0005] The main steam pipeline system in the fast reactor steam generator module functions to deliver steam generated by steam generator 7 to turbine 2 for power generation. When the steam generated by steam generator 7 cannot meet the inlet steam parameter requirements of turbine 2, or when turbine 2 is shut down, the steam is discharged to the condenser through the turbine 2 bypass valve. The fast reactor main steam pipeline system also serves as an overpressure protection system for steam generator 7. When the main steam pressure rises, the turbine 2 bypass valve, atmospheric release valve, and safety valve are opened sequentially to ensure the safety of steam generator 7. The fast reactor main steam pipeline system discharges heat generated by the reactor under normal operating conditions and accident conditions, but does not perform emergency accident safety heat discharge functions.

[0006] Isolation of main steam pipeline:

[0007] —The quick isolation valve should be designed to close within 3 seconds of receiving an isolation signal.

[0008] —The downstream electric isolation valve of the fast isolation valve should be designed to close within 15 seconds after receiving an isolation signal.

[0009] Overpressure protection:

[0010] —Each steam generator module is equipped with 3 safety valves and 2 atmospheric release valves.

[0011] The main steam pipeline system of the fast reactor is a newly designed process system, and its functions need to be commissioned before it is officially put into operation. However, the design manual and related literature for the main steam pipeline system of the fast reactor do not provide specific instructions on how to conduct commissioning tests, nor do they provide any instructions on the commissioning requirements of the system. Summary of the Invention

[0012] The technical problem to be solved by the present invention is to address the above-mentioned deficiencies in the prior art by providing a commissioning method for the main steam pipeline system of a sodium-cooled fast reactor, which comprehensively and efficiently verifies the function of the main steam pipeline system of the sodium-cooled fast reactor.

[0013] The technical solution adopted to solve the technical problem of this invention is to provide a commissioning method for the main steam pipeline system of a sodium-cooled fast reactor. The main steam pipeline system includes: a steam generator of the sodium-cooled fast reactor, a superheater of the sodium-cooled fast reactor, a first main steam pipeline, a second main steam pipeline, an atmospheric discharge pipeline, a first branch pipeline, a second branch pipeline, a quick isolation valve, an electrically operated isolation valve, an atmospheric release valve, and a main steam safety valve. The steam generator and the superheater are connected through the first main steam pipeline. The superheater is used to dehumidify the steam discharged from the steam generator to obtain dehumidified steam. The superheater outlet is connected to the second main steam pipeline. The quick isolation valve and the electrically operated isolation valve are installed on the second main steam pipeline, with the quick isolation valve upstream of the electrically operated isolation valve. The atmospheric discharge pipeline is installed on the first main steam pipeline. The first branch pipeline is installed on the atmospheric discharge pipeline. The second branch pipeline is installed on the atmospheric discharge pipeline. The first branch pipeline is equipped with an atmospheric release valve and a main steam safety valve, and the second branch pipeline is equipped with an atmospheric release valve and a main steam safety valve. The commissioning method includes the following steps:

[0014] Based on the functions of the sodium-cooled fast reactor main steam pipeline system, the equipment in the sodium-cooled fast reactor main steam pipeline system that needs to be commissioned was selected;

[0015] Based on the equipment that needs to be commissioned in the main steam pipeline system of the sodium-cooled fast reactor, conduct performance analysis on the equipment and determine the commissioning test items and contents to be performed for each piece of equipment;

[0016] Determine the technical requirements and sequence of commissioning tests to be performed on each device.

[0017] Preferably, the equipment in the selected sodium-cooled fast reactor main steam pipeline system that needs to be commissioned includes the fast isolation valve, the electrically operated isolation valve, the atmospheric release valve, and the main steam safety valve.

[0018] Preferably, the performance analysis of the equipment required for commissioning of the sodium-cooled fast reactor main steam pipeline system includes the following steps:

[0019] Performance analysis of the main steam quick isolation valve: Based on the fact that the quick isolation valve closes within the first preset time after receiving the isolation signal when the steam generator leaks or the first main steam pipeline breaks, the main steam quick isolation valve is determined to be debugged.

[0020] Performance analysis of the electric isolation valve: Based on the fact that the electric isolation valve closes within a second preset time after receiving an isolation signal, the electric isolation valve is determined for testing.

[0021] Performance analysis of the atmospheric release valve: Based on the failure of the turbine bypass system connected to the sodium-cooled fast reactor main steam pipeline system and / or the sudden closure of the fast isolation valve, if the pressure in the sodium-cooled fast reactor main steam pipeline system exceeds the set pressure of the atmospheric release valve, steam will be discharged to the atmosphere through the atmospheric release valve to limit the pressure of the sodium-cooled fast reactor main steam pipeline system below the opening pressure of the main steam safety valve, thus preventing the main steam safety valve from opening. In the event of steam generator leakage (sodium water accident), the atmospheric release valve will be opened to quickly depressurize the module and discharge the steam on the sodium-cooled fast reactor third loop system side connected to the sodium-cooled fast reactor main steam pipeline system to the atmosphere to mitigate the consequences of the accident. The atmospheric release valve needs to be adjusted accordingly.

[0022] Performance analysis of the main steam safety valve: The main steam safety valve is used for overpressure protection of the steam pipeline on the third loop system side of the sodium-cooled fast reactor connected to the main steam pipeline system of the steam generator. When the atmospheric relief valve fails, steam is discharged to the atmosphere through the main steam safety valve to control the pressure value in the steam generator so that it does not exceed the design pressure of the steam generator. The main steam safety valve is then determined for commissioning.

[0023] Preferably, the atmospheric emission pipeline includes: a first atmospheric emission pipeline and a second atmospheric emission pipeline. The first atmospheric emission pipeline is located on the first main steam pipeline near the steam generator. The distance between the connection point of the first atmospheric emission pipeline and the first main steam pipeline and the outlet of the steam generator is a preset first distance. The second atmospheric emission pipeline is located on the first main steam pipeline near the superheater. The distance between the connection point of the second atmospheric emission pipeline and the first main steam pipeline and the inlet of the superheater is a preset second distance. The first branch pipeline includes: a first branch line and a second branch line. The first branch line is located on the first atmospheric emission pipeline, and the second branch line is located on the second atmospheric emission pipeline.

[0024] The second branch pipeline includes: a third branch, a fourth branch, and a fifth branch. The third branch is connected to the first atmospheric emission pipeline, the fourth branch is connected to the first atmospheric emission pipeline, and the fifth branch is connected to the second atmospheric emission pipeline.

[0025] The atmospheric relief valve includes a first atmospheric relief valve and a second atmospheric relief valve. The main steam safety valve includes a first main steam safety valve, a second main steam safety valve, and a third main steam safety valve. The first atmospheric relief valve is located in the first branch line, the second atmospheric relief valve is located in the second branch line, the first main steam safety valve is located in the third branch line, the second main steam safety valve is located in the fourth branch line, and the third main steam safety valve is located in the fifth branch line.

[0026] Preferably, the commissioning tests to be performed on each device include:

[0027] Preliminary tests include: system flushing of the sodium-cooled fast reactor main steam pipeline system, instrumentation and measurement channel tests, logic control channel tests, and valve performance tests;

[0028] Subsystem tests include: electric isolation valve test, main steam safety valve pressure setpoint test, quick isolation valve control test, and atmospheric release valve test;

[0029] The system's comprehensive performance debugging test includes: comprehensive test of electric isolation valve, comprehensive test of fast isolation valve, and comprehensive test of atmospheric release valve.

[0030] Preferably, the instrumentation and measurement channel test is to test the performance of the instruments of the sodium-cooled fast reactor main steam pipeline system and the sensors and actuators of the control unit of the sodium-cooled fast reactor main steam pipeline system, and to verify that the hardware and software meet the requirements.

[0031] The logic control channel test is used to test the performance of the actuators and contactors, as well as the signal processing, of the instrumentation and control units of the sodium-cooled fast reactor main steam pipeline system.

[0032] Valve performance testing involves checking the operation of valve limit switches, valve stem travel, operating time, and fail-safe position of valves in the main steam pipeline system of a sodium-cooled fast reactor under fluid-free conditions.

[0033] Preferably, the electric isolation valve test verifies the automatic operation and related alarms of the electric isolation valve;

[0034] The main steam safety valve pressure setting test is to check the correct operation and sealing of the main steam safety valve, and whether the displacement sensor signal of the main steam safety valve of the sodium-cooled fast reactor is correct.

[0035] The quick isolation valve control test verifies the operability of the quick isolation valve;

[0036] The atmospheric release valve test verifies the open-loop regulation characteristics of the atmospheric release valve during the cold-state performance test phase.

[0037] Preferably, the specific method for determining the commissioning sequence of the commissioning tests to be performed on each device is as follows:

[0038] First, perform the pressure setting test of the main steam safety valve, then perform the control test of the fast isolation valve and the automatic test of the electric isolation valve.

[0039] Preferably, the system comprehensive performance commissioning test is conducted after the generator unit connected to the main steam pipeline of the sodium-cooled fast reactor is fueled and the steam generator is in steam operation mode. This verifies the automatic operation of the fast isolation valve and the electric isolation valve and related alarms, checks that the atmospheric release valve is correctly adjusted, and maintains the steam generator pressure at the specified value.

[0040] Preferably, the specific method for determining the commissioning sequence of the commissioning tests to be performed on each device is as follows:

[0041] After completing the preliminary test, subsystem tests will be conducted, followed by comprehensive system performance debugging tests.

[0042] Preferably, determining the specific steps for the commissioning technical requirements and sequence of commissioning tests to be performed on each device includes the following:

[0043] Commissioning personnel completed the commissioning of the sodium-cooled fast reactor main steam pipeline system at different test stages, based on the installation schedule of equipment and components of the main steam pipeline system, the planned arrangement of commissioning work, and the time when the system was put into operation.

[0044] The commissioning method for the sodium-cooled fast reactor main steam pipeline system in this invention, under the premise of ensuring nuclear safety and the safety of personnel and equipment in sodium-cooled fast reactor nuclear power plants, analyzes the design characteristics of the sodium-cooled fast reactor main steam pipeline system and the actual needs of system commissioning, and provides a detailed description of the commissioning technical requirements for the system. The adoption of these commissioning technical requirements will be able to comprehensively and efficiently verify the function of the sodium-cooled fast reactor main steam pipeline system, and provide a strong guarantee to ensure that the sodium-cooled fast reactor main steam pipeline system can fully perform its functions in the event of a sodium-water accident. Attached Figure Description

[0045] Figure 1 This is a schematic diagram of the three-loop system of a sodium-cooled fast reactor;

[0046] Figure 2 This is a schematic diagram of the main steam pipeline system of the sodium-cooled fast reactor in Example 2.

[0047] In the diagram: 1-Generator; 2-Steam turbine; 3-Condenser; 4-Deaerator; 5-Bypass valve; 6-Main feedwater pump; 7-Steam generator; 8-Superheater; 9-First main steam pipe; 10-Second main steam pipe; 14-Quick isolation valve; 15-Electric isolation valve; 18-First atmospheric vent pipe; 19-Second atmospheric vent pipe; 20-First branch; 21-Second branch; 22-Third branch; 23-Fourth branch; 24-Fifth branch;

[0048] 25-First atmospheric relief valve; 26-Second atmospheric relief valve; 27-First main steam safety valve;

[0049] 28 - Second main steam safety valve; 29 - Third main steam safety valve. Detailed Implementation

[0050] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0051] The embodiments of this patent are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this patent, and should not be construed as limiting this patent.

[0052] Example 1

[0053] This embodiment provides a commissioning method for a sodium-cooled fast reactor main steam pipeline system. The sodium-cooled fast reactor main steam pipeline system includes: a steam generator of the sodium-cooled fast reactor, a superheater of the sodium-cooled fast reactor, a first main steam pipeline, a second main steam pipeline, an atmospheric discharge pipeline, a first branch pipeline, a second branch pipeline, a quick isolation valve, an electrically operated isolation valve, an atmospheric release valve, and a main steam safety valve. The steam generator and the superheater are connected through the first main steam pipeline. The superheater is used to dehumidify the steam discharged from the steam generator to obtain dehumidified steam. The superheater outlet is connected to the second main steam pipeline. The quick isolation valve and the electrically operated isolation valve are installed on the second main steam pipeline, with the quick isolation valve upstream of the electrically operated isolation valve. The atmospheric discharge pipeline is installed on the first main steam pipeline. The first branch pipeline is installed on the atmospheric discharge pipeline. The second branch pipeline is installed on the atmospheric discharge pipeline. The first branch pipeline is equipped with an atmospheric release valve and a main steam safety valve. The commissioning method includes the following steps:

[0054] Based on the functions of the sodium-cooled fast reactor main steam pipeline system, the equipment in the sodium-cooled fast reactor main steam pipeline system that needs to be commissioned was selected;

[0055] Based on the equipment that needs to be commissioned in the main steam pipeline system of the sodium-cooled fast reactor, conduct performance analysis on the equipment and determine the commissioning test items and contents to be performed for each piece of equipment;

[0056] Determine the technical requirements and sequence of commissioning tests to be performed on each device.

[0057] The commissioning method for the sodium-cooled fast reactor main steam pipeline system in this embodiment, under the premise of ensuring nuclear safety and the safety of personnel and equipment in the sodium-cooled fast reactor nuclear power plant, analyzes the design characteristics of the sodium-cooled fast reactor main steam pipeline system and the actual needs of system commissioning. It provides a detailed description of the commissioning technical requirements for the system. The adoption of these commissioning technical requirements will be able to comprehensively and efficiently verify the function of the sodium-cooled fast reactor main steam pipeline system, and provide a strong guarantee to ensure that the sodium-cooled fast reactor main steam pipeline system can fully perform its functions in the event of a sodium water accident.

[0058] Example 2

[0059] This embodiment provides a commissioning method for the main steam pipeline system of a sodium-cooled fast reactor, such as... Figure 2 As shown, the main steam pipeline system of the sodium-cooled fast reactor includes: a steam generator 7, a superheater 8, a first main steam pipeline 9, a second main steam pipeline 10, an atmospheric discharge pipeline, a first branch pipeline, a second branch pipeline, a quick isolation valve 14, an electrically operated isolation valve 15, an atmospheric release valve, and a main steam safety valve. The steam generator 7 and the superheater 8 are connected through the first main steam pipeline 9. The superheater 8 is used to dehumidify the steam discharged from the steam generator 7 to obtain dehumidified steam. The outlet of the superheater 8 is connected to the second main steam pipeline 10. The quick isolation valve 14 and the electrically operated isolation valve 15 are installed on the second main steam pipeline 10, with the quick isolation valve 14 upstream of the electrically operated isolation valve 15. The atmospheric discharge pipeline is installed on the first main steam pipeline 9. The first branch pipeline is installed on the atmospheric discharge pipeline, and the second branch pipeline is installed on the atmospheric discharge pipeline. The first branch pipeline is equipped with an atmospheric release valve and a main steam safety valve, and the second branch pipeline is equipped with an atmospheric release valve and a main steam safety valve. The commissioning method includes the following steps:

[0060] (1) Based on the function of the sodium-cooled fast reactor main steam pipeline system, select the equipment that needs to be commissioned in the sodium-cooled fast reactor main steam pipeline system;

[0061] The main function of the sodium-cooled fast reactor main steam pipeline system is:

[0062] Steam generated by steam generator 7 is sent to the steam turbine for power generation. When the steam generated by steam generator 7 cannot meet the steam inlet parameters of the steam turbine or when the steam turbine is shut down, the steam is discharged through the steam turbine bypass valve. This system plays the role of overpressure protection for steam generator 7. When the main steam pressure rises, the steam generator 7 is ensured to be safe by opening the steam turbine bypass valve, the atmospheric release valve of the sodium-cooled fast reactor main steam pipeline system and the main steam safety valve in sequence.

[0063] The main steam pipeline system of the sodium-cooled fast reactor discharges the heat generated by the reactor under normal operating conditions and accident conditions of the power plant, but does not undertake the function of emergency accident safety heat discharge.

[0064] After a sodium-water reaction occurs due to a leak in the heat transfer pipe of steam generator 7, this system undertakes the functions of main steam isolation (achieved through quick isolation valve 14 and electric isolation valve 15) and subsequent steam exhaust.

[0065] The main equipment of the sodium-cooled fast reactor main steam pipeline system includes a fast isolation valve 14, an electrically operated isolation valve 15, an atmospheric release valve, and a main steam safety valve.

[0066] (2) Based on the equipment that needs to be commissioned in the main steam pipeline system of the sodium-cooled fast reactor, conduct performance analysis on the equipment and determine the commissioning test items and contents to be performed for each piece of equipment.

[0067] Specifically, by analyzing the functions and performance of the main steam pipeline system of the sodium-cooled fast reactor, the test content of the main steam pipeline system of the sodium-cooled fast reactor was determined.

[0068] (3) Determine the technical requirements and sequence of the commissioning tests to be performed on each device.

[0069] After the main steam pipeline system of the sodium-cooled fast reactor was installed, it entered the commissioning phase, and the system commissioning verified that its performance met the design requirements.

[0070] When steam generator 7 leaks, the quick isolation valve 14 closes within 3 seconds of receiving the isolation signal, and the electrically operated isolation valve 15 closes within 15 seconds of receiving the isolation signal, participating in the isolation of steam generator 7. The atmospheric release valve opens, releasing steam and water from the third loop side to the atmosphere, thereby reducing the pressure inside the isolated steam generator 7 and protecting it. The main steam safety valve is an overpressure protection device for the steam pipelines (within the module) of steam generator 7 and the sodium-cooled fast reactor third loop system. When the atmospheric release valve fails, steam can be released to the atmosphere through the main steam safety valve to control the pressure inside steam generator 7 and ensure it does not exceed the design pressure of steam generator 7.

[0071] Because the sodium-cooled fast reactor (NSCR) main steam pipeline system is a newly designed system, there is currently no method for commissioning it, leading to increased difficulty and workload in the commissioning process. To ensure the smooth and orderly commissioning of the NSCR main steam pipeline system, this embodiment proposes a commissioning method for the NSCR main steam pipeline system, verifying that its performance meets design requirements and performance standards. This method is based on the design characteristics of the NSCR main steam pipeline system. By analyzing the system's various functions and configurations, it designs the commissioning test items to be carried out, the specific implementation plan and content of the commissioning tests, the acceptance criteria for each test, and the logical sequence of execution between them.

[0072] This embodiment comprehensively verifies that the design, manufacture, and installation of the entire system meet the design requirements and system performance standards by analyzing and designing reasonable and complete test items and accurate and easy-to-judge acceptance criteria. This ensures that the system can assume the main steam isolation and subsequent exhaust functions after the sodium-water reaction occurs due to leakage in the heat transfer pipe of steam generator 7.

[0073] There are design differences between fast reactors and current pressurized water reactors. The hot functional test conditions for fast reactors differ significantly from those for pressurized water reactors. During the hot functional test of a fast reactor, there is no steam in the third loop, while in a pressurized water reactor, steam is present in the second loop. The closing time of the isolation valves in the steam line of a pressurized water reactor can be verified during the hot functional test, but this is not suitable for fast reactors. Current pressurized water reactor commissioning experience is not applicable to the main steam line system of fast reactors. To ensure the safe operation of the main steam line system, the commissioning content of the main steam line system should be scientifically analyzed to ensure its functionality can be verified. The main steam line system of fast reactors increases the difficulty and workload of commissioning, particularly impacting the unit commissioning schedule, manpower, material resources, financial investment, and testing risks.

[0074] This embodiment is based on the main functions and design features of the sodium-cooled fast reactor main steam pipeline system. By analyzing the various configurations and functions of the system, the specific content of its commissioning technical requirements is determined.

[0075] Preferably, the equipment in the selected sodium-cooled fast reactor main steam pipeline system that needs to be commissioned is the fast isolation valve 14, the electric isolation valve 15, the atmospheric release valve, and the main steam safety valve.

[0076] Preferably, the performance analysis of the equipment required for commissioning of the sodium-cooled fast reactor main steam pipeline system includes the following steps:

[0077] Performance analysis of the main steam quick isolation valve 14: Based on the fact that when the steam generator 7 leaks or the first main steam pipeline 9 breaks, the quick isolation valve 14 will close within a first preset time after receiving the isolation signal to prevent the accident from escalating, the main steam quick isolation valve 14 is to be adjusted; the first preset time is 3 seconds.

[0078] Performance analysis of the electric isolation valve 15: Based on the fact that the electric isolation valve 15 closes within a second preset time after receiving the isolation signal, the electric isolation valve 15 is determined to be debugged; the second preset time is 15 seconds.

[0079] Performance analysis of the atmospheric release valve: Based on the failure of the turbine bypass system connected to the sodium-cooled fast reactor main steam pipeline system and / or the sudden closure of the fast isolation valve 14, if the pressure in the sodium-cooled fast reactor main steam pipeline system exceeds the set pressure of the atmospheric release valve, steam will be discharged to the atmosphere through the atmospheric release valve to limit the pressure of the sodium-cooled fast reactor main steam pipeline system below the opening pressure of the main steam safety valve, thus preventing the main steam safety valve from opening. In the event of leakage in the steam generator 7 (sodium water accident), the atmospheric release valve will be opened to quickly depressurize the module and discharge the steam on the sodium-cooled fast reactor third loop system side connected to the sodium-cooled fast reactor main steam pipeline system to the atmosphere to mitigate the consequences of the accident. The atmospheric release valve needs to be adjusted accordingly.

[0080] Performance analysis of the main steam safety valve: Based on the fact that the main steam safety valve is used for overpressure protection of the steam pipeline on the third loop system side of the sodium-cooled fast reactor connected to the main steam pipeline system of the steam generator 7, when the atmospheric release valve fails, steam is discharged to the atmosphere through the main steam safety valve to control the pressure value in the steam generator 7 so that it does not exceed the design pressure of the steam generator 7, the main steam safety valve is determined and commissioned.

[0081] like Figure 2 As shown, preferably, the atmospheric emission pipeline includes: a first atmospheric emission pipeline 18 and a second atmospheric emission pipeline 19. The first atmospheric emission pipeline 18 is located on the first main steam pipeline 9 near the steam generator 7, and the distance between the connection point of the first atmospheric emission pipeline 18 and the first main steam pipeline 9 and the outlet of the steam generator 7 is a preset first distance. The second atmospheric emission pipeline 19 is located on the first main steam pipeline 9 near the superheater 8, and the distance between the connection point of the second atmospheric emission pipeline 19 and the first main steam pipeline 9 and the inlet of the superheater 8 is a preset second distance. The first branch pipeline includes: a first branch 20 and a second branch 21. The first branch 20 is located on the first atmospheric emission pipeline 18, and the second branch 21 is located on the second atmospheric emission pipeline 19.

[0082] The second branch pipeline includes: a third branch 22, a fourth branch 23, and a fifth branch 24. The third branch 22 is installed on the first atmospheric emission pipeline 18, the fourth branch 23 is installed on the first atmospheric emission pipeline 18, and the fifth branch 24 is installed on the second atmospheric emission pipeline 19.

[0083] The atmospheric relief valve includes a first atmospheric relief valve 25 and a second atmospheric relief valve 26. The main steam safety valve includes a first main steam safety valve 27, a second main steam safety valve 28, and a third main steam safety valve 29. The first atmospheric relief valve 25 is located in the first branch line 20, the second atmospheric relief valve 26 is located in the second branch line 21, the first main steam safety valve 27 is located in the third branch line 22, the second main steam safety valve 28 is located in the fourth branch line 23, and the third main steam safety valve 29 is located in the fifth branch line 24.

[0084] Preferably, the commissioning tests to be performed on each device include:

[0085] The preliminary tests include: system flushing of the sodium-cooled fast reactor main steam pipeline system, instrumentation and measurement channel tests of the sodium-cooled fast reactor main steam pipeline system, logic control channel tests of the sodium-cooled fast reactor main steam pipeline system, and valve performance tests of the sodium-cooled fast reactor main steam pipeline system. The preliminary tests are conducted during the cold performance test phase, which is a test at room temperature.

[0086] Subsystem tests include: electric isolation valve 15 test, main steam safety valve pressure setpoint test, quick isolation valve 14 control test, and atmospheric release valve test. The atmospheric release valve test is conducted during the cold-state performance test phase, while the other subsystem tests are conducted during the hot-state performance test phase. The hot-state performance test verifies the performance of each device under operating conditions that are as close as possible to actual temperature, pressure, and flow rate. The atmospheric release valve test will result in nitrogen loss; therefore, it is scheduled to be conducted during the cold-state performance test phase. The atmospheric release valve test verifies the open-loop regulation characteristics of the atmospheric release valve during the cold-state performance test phase.

[0087] The system's comprehensive performance debugging test includes: comprehensive test of electric isolation valve 15, comprehensive test of fast isolation valve 14, and comprehensive test of atmospheric release valve.

[0088] The system's comprehensive performance debugging test was conducted during the power operation test phase to verify that the equipment could operate stably under various power platforms.

[0089] Based on the fundamental principles of commissioning the sodium-cooled fast reactor main steam pipeline system, preliminary tests are conducted first, followed by subsystem tests, and finally, comprehensive system performance commissioning tests are carried out. The stages of each commissioning test for the system are determined according to the installation schedule of the equipment and components of the sodium-cooled fast reactor main steam pipeline system, the commissioning work plan, and the system's commissioning time.

[0090] Preferably, the instrumentation and measurement channel test is to test the performance of the instruments of the sodium-cooled fast reactor main steam pipeline system and the sensors and actuators of the control unit of the sodium-cooled fast reactor main steam pipeline system, and to verify that the hardware and software meet the requirements.

[0091] The logic control channel test is used to test the performance of the actuators and contactors, as well as the signal processing, of the instrumentation and control units of the sodium-cooled fast reactor main steam pipeline system.

[0092] Valve performance testing is conducted on valves under fluid-free conditions. The inspection includes: the operation of valve limit switches and valve stem travel in the main steam pipeline system of sodium-cooled fast reactors, measurement of operating time, and inspection of fail-safe positions.

[0093] Preferably, the test of the electric isolation valve 15 is to verify the automatic operation of the electric isolation valve 15 and related alarms;

[0094] The main steam safety valve pressure setting test is to check the correct operation and sealing of the main steam safety valve, and whether the displacement sensor signal of the main steam safety valve of the sodium-cooled fast reactor is correct.

[0095] The control test of the quick isolation valve 14 is to verify the operability of the quick isolation valve 14.

[0096] The atmospheric release valve test verifies the open-loop regulation characteristics of the atmospheric release valve during the cold-state performance testing phase. The atmospheric release valve test is conducted during the cold-state performance testing phase.

[0097] Preferably, the specific method for determining the commissioning sequence of the commissioning tests to be performed on each device is as follows:

[0098] First, perform the pressure setting test of the main steam safety valve, then perform the control test of the quick isolation valve 14 and the automatic test of the electric isolation valve 15. Each test is conducted on different equipment. The main steam safety valve can provide accident protection for the automatic test of the electric isolation valve 15, so the test of the main steam safety valve is performed first.

[0099] Preferably, the system comprehensive performance commissioning test is conducted after the generator assembly connected to the main steam pipeline of the sodium-cooled fast reactor is fueled and the steam generator 7 is in steam operation condition. This verifies the automatic operation and related alarms of the fast isolation valve 14 and the electric isolation valve 15, checks that the atmospheric release valve is correctly adjusted, and maintains the pressure of the steam generator 7 at the specified value.

[0100] Preferably, the specific method for determining the commissioning sequence of the commissioning tests to be performed on each device is as follows:

[0101] After completing the preliminary test, subsystem tests will be conducted, followed by comprehensive system performance debugging tests.

[0102] Preferably, determining the specific steps for the commissioning technical requirements and sequence of commissioning tests to be performed on each device includes the following:

[0103] Commissioning personnel completed the commissioning of the sodium-cooled fast reactor main steam pipeline system at different test stages, based on the installation schedule of equipment and components of the main steam pipeline system, the planned arrangement of commissioning work, and the time when the system was put into operation.

[0104] As shown in Table 1 below, the commissioning technical requirements and execution sequence are as follows for different test execution stages of the commissioning method for the main steam pipeline system of the sodium-cooled fast reactor.

[0105]

[0106] Table 1

[0107] The expected effects of this patent on the above technical solution are mainly as follows:

[0108] Technical Solution Step (1) By analyzing the functions of the sodium-cooled fast reactor main steam pipeline system, the equipment that needs to be commissioned is determined. The purpose is to determine the equipment that needs to be commissioned based on the main functions of the sodium-cooled fast reactor main steam pipeline system, thereby providing a reference and basis for the subsequent performance analysis and commissioning content of the sodium-cooled fast reactor main steam pipeline system equipment;

[0109] Step (2) of the technical solution, based on the functional analysis results of the sodium-cooled fast reactor main steam pipeline system, analyzes the commissioning test items and contents that should be performed on individual equipment and components of the sodium-cooled fast reactor main steam pipeline system. The purpose is to utilize the performance analysis results of the equipment to determine the commissioning test items and contents that should be performed on the equipment to realize the function of the fast reactor main steam pipeline system, to perform performance judgment and inspection on the equipment during the installation of the fast reactor main steam pipeline system, and to ensure that the basic performance and related data of the equipment meet the requirements. This technical solution step can ensure the comprehensiveness, completeness, and rationality of the commissioning test items for the fast reactor main steam pipeline system.

[0110] Step (3) of the technical solution is the technical requirements and sequence for the comprehensive performance commissioning of the fast reactor main steam pipeline system, ensuring that the safety functions of the fast reactor main steam pipeline system are effectively verified. In order to ensure that the basic performance and related data of the nuclear power equipment meet the content of the safety report analysis, and to prove that the performance of the nuclear power equipment meets the relevant regulations of the National Nuclear Safety Administration, the comprehensive performance commissioning of the fast reactor main steam pipeline system should be combined with the results of the accident analysis, and a simulated leakage accident of steam generator 7 should be introduced to verify that the main steam isolation and subsequent exhaust functions of the fast reactor main steam pipeline system meet the requirements.

[0111] The commissioning method for the sodium-cooled fast reactor main steam pipeline system in this embodiment, under the premise of ensuring nuclear safety and the safety of personnel and equipment in the sodium-cooled fast reactor nuclear power plant, analyzes the design characteristics of the sodium-cooled fast reactor main steam pipeline system and the actual needs of system commissioning. It provides a detailed description of the commissioning technical requirements for the system. The adoption of these commissioning technical requirements will be able to comprehensively and efficiently verify the function of the sodium-cooled fast reactor main steam pipeline system, and provide a strong guarantee to ensure that the sodium-cooled fast reactor main steam pipeline system can fully perform its functions in the event of a sodium water accident.

[0112] It is understood that the above embodiments are merely exemplary implementations used to illustrate the principles of the present invention, and the present invention is not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also considered to be within the scope of protection of the present invention.

Claims

1. A commissioning method for a sodium-cooled fast reactor main steam pipeline system, the sodium-cooled fast reactor main steam pipeline system comprising: The sodium-cooled fast reactor includes a steam generator, a superheater, a first main steam pipe, a second main steam pipe, an atmospheric exhaust pipe, a first branch pipe, a second branch pipe, a quick isolation valve, an electrically operated isolation valve, an atmospheric release valve, and a main steam safety valve. The steam generator and superheater are connected via the first main steam pipe. The superheater dehumidifies the steam discharged from the steam generator to obtain dehumidified steam. The superheater outlet is connected to the second main steam pipe. The quick isolation valve and the electrically operated isolation valve are located on the second main steam pipe, with the quick isolation valve upstream of the electrically operated isolation valve. The atmospheric exhaust pipe is located on the first main steam pipe. The first branch pipe is located on the atmospheric exhaust pipe, and the second branch pipe is located on the atmospheric exhaust pipe. Both the first branch pipe and the second branch pipe are equipped with atmospheric release valves and main steam safety valves. The commissioning method includes the following steps: Based on the functions of the sodium-cooled fast reactor main steam pipeline system, the equipment that needs to be commissioned in the sodium-cooled fast reactor main steam pipeline system is selected. The selected equipment that needs to be commissioned in the sodium-cooled fast reactor main steam pipeline system is the fast isolation valve, the electric isolation valve, the atmospheric release valve, and the main steam safety valve. Based on the equipment requiring commissioning in the sodium-cooled fast reactor main steam pipeline system, performance analysis was conducted on the equipment to determine the commissioning test items and contents to be performed on each piece of equipment. The commissioning test items to be performed on each piece of equipment include: Preliminary tests include: system flushing of the sodium-cooled fast reactor main steam pipeline system, instrumentation and measurement channel tests, logic control channel tests, and valve performance tests; Subsystem tests include: electric isolation valve test, main steam safety valve pressure setpoint test, quick isolation valve control test, and atmospheric release valve test; System comprehensive performance debugging tests, including: comprehensive tests of electric isolation valves, comprehensive tests of fast isolation valves, and comprehensive tests of atmospheric release valves; Determine the technical requirements and sequence of commissioning tests to be performed on each device.

2. The commissioning method for the main steam pipeline system of a sodium-cooled fast reactor according to claim 1, characterized in that, Based on the equipment requiring commissioning of the sodium-cooled fast reactor main steam pipeline system, the performance analysis of the equipment specifically includes the following steps: Performance analysis of the main steam quick isolation valve: Based on the fact that the quick isolation valve closes within the first preset time after receiving the isolation signal when the steam generator leaks or the first main steam pipeline breaks, the main steam quick isolation valve is determined to be debugged. Performance analysis of the electric isolation valve: Based on the fact that the electric isolation valve closes within a second preset time after receiving an isolation signal, the electric isolation valve is determined for testing. Performance analysis of the atmospheric release valve: Based on the failure of the turbine bypass system connected to the sodium-cooled fast reactor main steam pipeline system and / or the sudden closure of the fast isolation valve, if the pressure in the sodium-cooled fast reactor main steam pipeline system exceeds the set pressure of the atmospheric release valve, steam will be discharged to the atmosphere through the atmospheric release valve to limit the pressure of the sodium-cooled fast reactor main steam pipeline system to below the opening pressure of the main steam safety valve. When the steam generator leaks, the atmospheric release valve will be opened to relieve pressure and discharge the steam on the sodium-cooled fast reactor third loop system side connected to the sodium-cooled fast reactor main steam pipeline system to the atmosphere. The atmospheric release valve needs to be adjusted accordingly. Performance analysis of the main steam safety valve: Since the main steam safety valve is used for overpressure protection of the steam generator, when the atmospheric relief valve fails, steam is discharged to the atmosphere through the main steam safety valve to control the pressure value in the steam generator so that it does not exceed the design pressure of the steam generator, the main steam safety valve is determined and adjusted.

3. The commissioning method for the main steam pipeline system of a sodium-cooled fast reactor according to claim 1, characterized in that, The atmospheric emission pipeline includes: a first atmospheric emission pipeline and a second atmospheric emission pipeline. The first atmospheric emission pipeline is located on the first main steam pipeline near the steam generator, and the second atmospheric emission pipeline is located on the first main steam pipeline near the superheater. The first branch pipeline includes: a first branch line and a second branch line. The first branch line is located on the first atmospheric emission pipeline, and the second branch line is located on the second atmospheric emission pipeline. The second branch pipeline includes: a third branch, a fourth branch, and a fifth branch. The third branch is connected to the first atmospheric emission pipeline, the fourth branch is connected to the first atmospheric emission pipeline, and the fifth branch is connected to the second atmospheric emission pipeline. The atmospheric relief valve includes a first atmospheric relief valve and a second atmospheric relief valve. The main steam safety valve includes a first main steam safety valve, a second main steam safety valve, and a third main steam safety valve. The first atmospheric relief valve is located in the first branch line, the second atmospheric relief valve is located in the second branch line, the first main steam safety valve is located in the third branch line, the second main steam safety valve is located in the fourth branch line, and the third main steam safety valve is located in the fifth branch line.

4. The commissioning method for the main steam pipeline system of a sodium-cooled fast reactor according to claim 1, characterized in that, The instrumentation and measurement channel test is to test the performance of the instruments and sensors and actuators of the control unit of the sodium-cooled fast reactor main steam pipeline system, and to verify that the hardware and software meet the requirements. The logic control channel test is used to test the performance of the actuators and contactors, as well as the signal processing, of the instrumentation and control units of the sodium-cooled fast reactor main steam pipeline system. Valve performance testing involves checking the operation of valve limit switches, valve stem travel, operating time, and fail-safe position of valves in the main steam pipeline system of a sodium-cooled fast reactor under fluid-free conditions.

5. The commissioning method for the main steam pipeline system of a sodium-cooled fast reactor according to claim 1, characterized in that, The test of the electric isolation valve is to verify the automatic operation and related alarms of the electric isolation valve; The main steam safety valve pressure setting test is to check the correct operation and sealing of the main steam safety valve, and whether the displacement sensor signal of the main steam safety valve of the sodium-cooled fast reactor is correct. The quick isolation valve control test verifies the operability of the quick isolation valve; The atmospheric release valve test verifies the open-loop regulation characteristics of the atmospheric release valve during the cold-state performance test phase.

6. The commissioning method for the main steam pipeline system of a sodium-cooled fast reactor according to claim 5, characterized in that, The specific method for determining the commissioning sequence of the commissioning tests to be performed on each device is as follows: First, perform the pressure setting test of the main steam safety valve, then perform the control test of the fast isolation valve and the automatic test of the electric isolation valve.

7. The commissioning method for the main steam pipeline system of a sodium-cooled fast reactor according to claim 1, characterized in that, The system's comprehensive performance commissioning test was conducted after the generator set, connected to the main steam pipeline of the sodium-cooled fast reactor, was fueled and the steam generator was in steam operation. The test verified the automatic operation of the fast isolation valve and the electric isolation valve, as well as related alarms. It also checked that the atmospheric release valve was properly adjusted and that the steam generator pressure was maintained at the specified value.

8. The commissioning method for the main steam pipeline system of a sodium-cooled fast reactor according to any one of claims 1, 4 to 7, characterized in that, The specific method for determining the commissioning sequence of the commissioning tests to be performed on each device is as follows: After completing the preliminary test, subsystem tests will be conducted, followed by comprehensive system performance debugging tests.

9. The commissioning method for the main steam pipeline system of a sodium-cooled fast reactor according to any one of claims 1 to 7, characterized in that, The specific steps for determining the commissioning technical requirements and sequence of commissioning tests to be performed on each device include: Commissioning personnel completed the commissioning of the sodium-cooled fast reactor main steam pipeline system at different test stages, based on the installation schedule of equipment and components of the main steam pipeline system, the planned arrangement of commissioning work, and the time when the system was put into operation.

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