Nuclear power plant unit refueling after large repair loop filling method and system

Abstract

The present application relates to a method and system for filling water in a primary loop after overhaul charging of a nuclear power unit, comprising: performing preparation work before filling water; after the preparation work is completed, performing switch operation test of a to-be-tested actuator and water filling and exhaust work of a flowmeter; after the switch operation test of the to-be-tested actuator is completed, performing performance test of a high-pressure safety injection pump; after the performance test of the high-pressure safety injection pump is completed, performing performance test of a low-pressure safety injection pump; after the performance test of the low-pressure safety injection pump is completed, filling water in the primary loop according to a preset water filling mode; judging whether a real-time water level of a reactor pool reaches a full water level; if yes, performing alarm action test. The present application can solve the problem of long time consumption, reduce workload, significantly improve work efficiency, reduce work risk and effectively save production cost by completing the preparation work in advance and arranging the alarm action test at the end.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of overhauling nuclear power plants, and more particularly to a method and system for filling a primary loop after refueling of a nuclear power unit. BACKGROUND

[0002] After refueling of a CPR1000 nuclear power unit, T*RIS002 test (test on an actuator not controlled by an injection signal), T*RIS010 test (test on a high-pressure injection pump, water filling of a reactor pool by alternately starting and stopping the high-pressure injection pump, and verification of the performance of the pump), T*RIS040 test (water filling of a reactor pool by starting and stopping a low-pressure injection pump, test on the flow of the low-pressure injection pump, and verification of the performance of the pump), and professional related work, and water filling of a primary loop are carried out. These works are basically works on a critical path or works affecting the critical path work, and if they are not reasonably arranged, the critical path work will be delayed.

[0003] Currently, after the low-low water level maintenance work of the primary loop is completed, TRIS015 / 016 (alarm action test) is executed to fill water by gravity to 11m (2 hours), then T*RIS010 / 040 test and T*RIS002 test are executed, and finally PTR002 pump is used to fill water in the pool to 19.5m (1.5 hours), and the total working period is 13 hours. After executing T*RIS015 / 016 to fill water by gravity to 11m and T*RIS010, T*RIS040 and T*RIS002 test may not be executed due to the fact that the liquid level of PTR001BA (water storage tank) does not meet the pump starting condition; and the water filling and air exhaust of the injection pipeline flow meter can only be executed after T4RIS015 / 016 gravity filling is completed, so T*RIS010 needs to wait for the completion of the water filling and air exhaust of the flow meter, resulting in a waste of a lot of time. SUMMARY

[0004] The technical problem to be solved by the present application is to provide a method and system for filling a primary loop after refueling of a nuclear power unit.

[0005] The technical solution adopted by the present application to solve the technical problem is that a method for filling a primary loop after refueling of a nuclear power unit is constructed, comprising the following steps:

[0006] Preparation work before water filling is executed;

[0007] After the preparation work is completed, switch operation test on a test actuator and water filling and air exhaust work of a flow meter are executed;

[0008] After the switch operation test on the test actuator is completed, performance test on a high-pressure injection pump is executed;

[0009] After the performance test of the high-pressure safety injection pump is completed, the performance test of the low-pressure safety injection pump is performed;

[0010] After the performance test of the low-pressure safety injection pump is completed, the primary loop is filled with water according to a preset water filling mode;

[0011] It is judged whether the real-time water level of the reactor pool reaches the full water level;

[0012] If yes, an alarm action test is performed.

[0013] In the method for filling the primary loop after refueling of the nuclear power unit in the application, the preparation work before the water filling includes:

[0014] Before the primary loop is filled with water, the concentrated boric acid injection tank is filled with water;

[0015] After the concentrated boric acid injection tank is filled with water, the preparation work for filling and exhausting the safety injection pipeline flowmeter is performed.

[0016] In the method for filling the primary loop after refueling of the nuclear power unit in the application, the preparation work before the primary loop is filled with water includes:

[0017] Before the primary loop is filled with water, the concentrated boric acid injection tank is filled with water through the direct boronization pipeline.

[0018] In the method for filling the primary loop after refueling of the nuclear power unit in the application, the preparation work before the primary loop is filled with water includes:

[0019] After the concentrated boric acid injection tank is filled with water, all the safety injection pipelines in the reactor safety injection system are filled with water through the direct boronization pipeline.

[0020] In the method for filling the primary loop after refueling of the nuclear power unit in the application, the method further includes:

[0021] During the process of filling all the safety injection pipelines with water, the flow information of all the safety injection pipelines is monitored in real time;

[0022] It is judged whether the safety injection pipeline is filled according to the flow information;

[0023] If all the safety injection pipelines are filled, it is determined that the preparation work is completed;

[0024] If any one or more safety injection pipelines are not filled, the safety injection pipelines that are not filled are continuously filled with water until they are filled.

[0025] In the method for filling the secondary loop after the overhaul and loading of the nuclear power unit, the filling of the primary loop according to the preset filling mode after the performance test of the low-pressure safety injection pump is completed comprises:

[0026] The low-pressure safety injection pump is kept running without stopping after the performance test of the low-pressure safety injection pump is completed;

[0027] The primary loop is filled based on the low-pressure safety injection pump;

[0028] The water level of the primary loop is monitored in real time;

[0029] It is judged whether the real-time water level of the reactor pool reaches the preset water level;

[0030] If yes, the primary loop is filled through bypass.

[0031] In the method for filling the secondary loop after the overhaul and loading of the nuclear power unit, the filling of the primary loop based on the low-pressure safety injection pump comprises:

[0032] The primary loop is filled based on the low-pressure safety injection pump in a double-end injection mode.

[0033] In the method for filling the secondary loop after the overhaul and loading of the nuclear power unit, the method further comprises:

[0034] The high-pressure safety injection pump is alternately started and stopped during the performance test of the high-pressure safety injection pump;

[0035] The low-pressure safety injection pump is alternately started and stopped during the performance test of the low-pressure safety injection pump.

[0036] The application further provides a system for filling the secondary loop after the overhaul and loading of the nuclear power unit, comprising:

[0037] An execution unit is configured to perform preparation work before filling;

[0038] A first test unit is configured to perform switch operation test of a to-be-tested execution mechanism and water filling and air exhausting work of a flowmeter after the preparation work is completed;

[0039] A second test unit is configured to perform performance test of a high-pressure safety injection pump after the switch operation test of the to-be-tested execution mechanism is completed;

[0040] A third test unit is configured to perform performance test of a low-pressure safety injection pump after the performance test of the high-pressure safety injection pump is completed;

[0041] A filling unit is configured to fill a primary loop according to a preset filling mode after the performance test of the low-pressure safety injection pump is completed;

[0042] A judgment unit is configured to judge whether the real-time water level of the reactor pool reaches the full water level.

[0043] An alarm test unit is configured to perform an alarm action test when the primary loop water level reaches the full water level.

[0044] In the nuclear power unit overhaul post-fueling primary loop water charging system, the execution unit comprises:

[0045] A water charging module is configured to charge the concentrated boric acid injection tank before the primary loop water inlet.

[0046] An exhaust work preparation module is configured to perform water charging and exhaust work preparation for the injection pipeline flowmeter after completing the water charging of the concentrated boric acid injection tank.

[0047] The nuclear power unit overhaul post-fueling primary loop water charging method and system have the following beneficial effects: the water charging preparation work is performed; after completing the preparation work, the switch operation test of the test execution mechanism and the water charging and exhaust work of the flowmeter are performed; after completing the switch operation test of the test execution mechanism, the performance test of the high-pressure injection pump is performed; after completing the performance test of the high-pressure injection pump, the performance test of the low-pressure injection pump is performed; after completing the performance test of the low-pressure injection pump, the primary loop is charged according to the preset water charging mode; whether the real-time water level of the reactor pool reaches the full water level is judged; if yes, the alarm action test is performed. The preparation work is completed in advance, and the alarm action test is arranged at the end, which can solve the problem of long time consumption, reduce the workload, significantly improve the work efficiency, reduce the work risk, and effectively save the production cost. BRIEF DESCRIPTION OF DRAWINGS

[0048] The application will be further described below in combination with the drawings and embodiments, and the drawings are as follows:

[0049] Figure 1 FIG. 1 is a flowchart of the nuclear power unit overhaul post-fueling primary loop water charging method provided by the embodiment of the application;

[0050] Figure 2 FIG. 2 is a structural schematic diagram of the nuclear power unit overhaul post-fueling primary loop water charging system provided by the embodiment of the application. DETAILED DESCRIPTION

[0051] The technical solutions in the embodiments of the application will be clearly and completely described below in combination with the drawings in the embodiments of the application. Obviously, the described embodiments are only part of the embodiments of the application, rather than all the embodiments of the application. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the application.

[0052] REFERENCEFigure 1 The application provides a method for filling water in a primary loop after refueling of a nuclear power unit, which is short in time consumption, can reduce workload and reduce mutual influence between work.

[0053] Specifically, as shown in the figure, the method for filling water in the primary loop after refueling of the nuclear power unit comprises the following steps: Figure 1

[0054] In step S101, the preparation work before water filling is performed.

[0055] In this step, the preparation work before water filling comprises: filling water in the concentrated boric acid injection tank before water filling in the primary loop; and performing water filling and air exhaust work preparation for the injection pipeline flow meter after the water filling in the concentrated boric acid injection tank is completed. Wherein, the water filling in the concentrated boric acid injection tank before water filling in the primary loop comprises: filling water in the concentrated boric acid injection tank through the direct boronization pipeline before water filling in the primary loop.

[0056] Specifically, the concentrated boric acid injection tank (RIS004BA) is filled with water through the direct boronization pipeline before water filling in the primary loop, and the water filling and air exhaust work preparation for the injection pipeline flow meter is performed after the RIS004BA is filled with water. Wherein, the RIS004BA is filled with water before water filling in the primary loop, so that the water filling work of the RIS004BA originally performed after the water filling in the primary loop is performed in advance, thereby no longer restricting the water filling in the primary loop, saving the key path of the water filling in the primary loop, and the circulating pumps (RIS021PO and RIS022PO) of the RIS004BA have conditions for re-identification after the RIS004BA is filled with water in advance, so that the re-identification work of the circulating pumps of the RIS004BA can be performed in advance and does not need to be arranged during the water filling in the primary loop, which greatly facilitates the plan arrangement of the re-identification work of the circulating pumps of the RIS004BA.

[0057] In the embodiment of the application, the water filling and air exhaust work preparation for the injection pipeline flow meter after the water filling in the concentrated boric acid injection tank is completed comprises: filling water in all injection pipelines in the reactor safety injection system through the direct boronization pipeline after the water filling in the concentrated boric acid injection tank is completed.

[0058] Specifically, after the water filling work of the RIS004BA is completed, water is filled in all injection pipelines in the reactor safety injection system (RIS) through the boronization pipeline, thereby creating conditions for the water filling and air exhaust work of the injection pipeline flow meter in advance and avoiding occupation of the key path.

[0059] ​It should be noted that the water filling and air exhausting work of the improved injection line flowmeter is arranged after the gravity water filling to 11 m (2 hours) in T*RIS015 / 016 (alarm action test). After improvement, all injection lines are filled with water by using the direct boron line, which is convenient to operate, optimizes the plan arrangement, and effectively saves the critical path time.

[0060] Further, in this step, the flow information of all injection lines is monitored in real time during the water filling of all injection lines; whether the injection lines are full is judged according to the flow information; if all injection lines are full, it is determined that the preparation work is completed; if any one or more injection lines are not full, the water filling of the injection lines not full is continued until the injection lines are full.

[0061] Specifically, during water filling, the water filling state of the injection line can be monitored in real time by reading the flowmeter or flowmeter on the injection line, so as to judge whether the injection line is full according to the reading of the flowmeter or flowmeter.

[0062] Step S102, after the preparation work is completed, the switch operation test of the test execution mechanism and the water filling and air exhausting work of the flowmeter are performed.

[0063] Specifically, after all injection lines are full of water, T*RIS002 test (i.e. switch operation test of the test execution mechanism, wherein the test execution mechanism can be an execution mechanism not controlled by the injection signal, such as an electric valve) can be performed. At the same time, the water filling and air exhausting work of the flowmeter is performed synchronously during the execution of T*RIS002 test.

[0064] Since the flow needs to be read in the subsequent test, the flowmeter processing work state must be ensured before the test, and the water filling and air exhausting work of the flowmeter requires that the injection line must be full of water. The execution window before optimization occupies the critical path all the time, and after optimization by the method of the present application, the critical path is no longer occupied.

[0065] Step S103, after the switch operation test of the test execution mechanism is completed, the performance test of the high-pressure injection pump is performed.

[0066] Specifically, after the switch operation test of the test execution mechanism is completed, the water filling and air exhausting work of the flowmeter is also completed, so T*RIS010 test (i.e. performance test of the high-pressure injection pump) can be immediately performed at this time without waiting. During the execution of T*RIS010 test, the high-pressure injection pump is alternately started and stopped to fill the reactor pool with water, and the flow of the high-pressure injection pump is checked to verify the performance of the high-pressure injection pump.

[0067] Step S104, after the performance test of the high-pressure safety injection pump is completed, the performance test of the low-pressure safety injection pump is performed.

[0068] Specifically, in this step, after the performance test of the high-pressure safety injection pump is completed, the T*RIS040 test (the performance test of the low-pressure safety injection pump, i.e., starting and stopping the low-pressure safety injection pump to fill the reactor pool with water, checking the flow of the low-pressure safety injection pump to verify the performance of the pump) is continued to be performed. During the T*RIS040 test, the low-pressure safety injection pump is alternately started and stopped.

[0069] Step S105, after the performance test of the low-pressure safety injection pump is completed, the one-loop is filled with water according to a preset filling mode.

[0070] In this step, after the performance test of the low-pressure safety injection pump is completed, the one-loop is filled with water according to the preset filling mode, including: after the performance test of the low-pressure safety injection pump is completed, keeping one low-pressure safety injection pump running without stopping the pump; filling the one-loop based on the low-pressure safety injection pump; monitoring the water level of the one-loop in real time; judging whether the real-time water level of the reactor pool reaches a preset water level; if yes, switching to a bypass to fill the one-loop. Wherein, filling the one-loop based on the low-pressure safety injection pump includes: filling the one-loop based on the low-pressure safety injection pump in a double-end injection mode.

[0071] Optionally, in the embodiment of the application, the preset water level can be 19 m.

[0072] Specifically, in this step, after the T*RIS040 test is completed, one low-pressure safety injection pump is kept running without stopping the pump, and the one-loop is filled with a large amount of water (about 900 m3 / h) by double-end injection of the low-pressure safety injection pump to 19 m, and then the one-loop is filled with water by switching to a bypass until the full water level is reached.

[0073] Wherein, the bypass injection is a bypass pipeline of the main pipeline of the double-end injection, the bypass pipeline of the main pipeline of the double-end injection has a small pipe diameter and a hole plate installed on the pipeline, so the flow is small, which can better control the later stage of water filling and avoid overflow of the reactor pool. In this way, the use of PTR002PO (the main water filling pump) for online recharging can be avoided, and the operation is reduced.

[0074] Step S106, judging whether the real-time water level of the reactor pool reaches a full water level.

[0075] In the embodiment of the application, the full water level can be 19.5 m.

[0076] Specifically, in this step, after the preset water level is reached, the water level of the reactor pool can be monitored by reading the real-time data of the liquid level meter in the reactor pool in real time to determine whether the water level reaches the full water level.

[0077] Step S107, if yes, an alarm action test is performed.

[0078] Specifically, the alarm action test is a test of switching operation verification of the electric valve on the injection pipeline.

[0079] The alarm action test is performed after the reactor pool is filled with water, and at this time, there is no time requirement. Therefore, the influence of the T*RIS040 test and the T*RIS002 test can be eliminated.

[0080] The present application not only can effectively save the critical path time (about 8 hours can be saved), but also cancels the online reuse PTR002PO water filling operation of the reactor pool, reduces the workload, and eliminates the mutual influence of the tests, improves the work efficiency, and reduces the work risk.

[0081] Reference Figure 2 The present application provides a nuclear power unit after overhaul charging one loop water filling system. The one loop water filling system comprises:

[0082] The execution unit 201 is used for performing water filling preparation work.

[0083] The execution unit 201 comprises: a water filling module, which is used for filling the concentrated boric acid injection tank before the one loop water inlet; and an exhaust work preparation module, which is used for performing water filling and exhaust work preparation of the injection pipeline flowmeter after the water filling of the concentrated boric acid injection tank is completed.

[0084] The first test unit 202 is used for performing switch operation test of the test execution mechanism and flowmeter water filling and exhaust work after the preparation work is completed.

[0085] The second test unit 203 is used for performing performance test of the high-pressure injection pump after the switch operation test of the test execution mechanism is completed.

[0086] The third test unit 204 is used for performing performance test of the low-pressure injection pump after the performance test of the high-pressure injection pump is completed.

[0087] The water filling unit 205 is used for filling the one loop according to a preset water filling mode after the performance test of the low-pressure injection pump is completed.

[0088] The judgment unit 206 is used for judging whether the real-time water level of the reactor pool reaches the full water level.

[0089] The alarm test unit 207 is used for performing alarm action test when the one loop water level reaches the full water level.

[0090] Specifically, the specific cooperation operation process between each unit in the post-refueling primary loop water charging system of the nuclear power unit can refer to the above-mentioned nuclear power unit post-refueling primary loop water charging method, which will not be described here.

[0091] Each embodiment in the specification is described in a progressive manner, and each embodiment focuses on the difference from other embodiments. The same or similar parts between each embodiment can be referred to each other. For the device disclosed by the embodiment, since it corresponds to the method disclosed by the embodiment, the description is relatively simple, and the relevant part can be referred to the method part.

[0092] The skilled person can further realize that the units and algorithm steps of each example described in combination with the embodiments disclosed herein can be realized by electronic hardware, computer software or a combination of the two. In order to clearly show the interchangeability of hardware and software, the composition and steps of each example have been described in the above description. Whether the functions are executed in hardware or software depends on the specific application and design constraints of the technical solution. The skilled person can use different methods to realize the described functions for each specific application, but such implementation should not be considered beyond the scope of the present application.

[0093] The steps of the method or algorithm described in combination with the embodiments disclosed herein can be directly implemented by hardware, software modules executed by a processor, or a combination of the two. The software modules can be placed in random access memory (RAM), memory, read-only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, hard disks, removable disks, CD-ROMs, or any other form of storage medium known in the art.

[0094] The above embodiments are only for illustrating the technical concept and characteristics of the present application, and the purpose is to enable those skilled in the art to understand the content of the present application and implement it accordingly, and cannot limit the protection scope of the present application. Any equivalent changes and modifications made within the scope of the claims of the present application shall belong to the scope of the claims of the present application.

Claims

1. A method for filling a primary circuit of a nuclear power plant with water after refueling, characterized in that, The method comprises the following steps: performing pre-filling preparation; after the preparation is completed, performing switch operation test on the actuator to be tested and filling and degassing work of the flowmeter; after the switch operation test on the actuator to be tested is completed, performing performance test on the high-pressure safety injection pump; after the performance test on the high-pressure safety injection pump is completed, performing performance test on the low-pressure safety injection pump; after the performance test on the low-pressure safety injection pump is completed, filling the primary loop according to a preset filling mode; judging whether the real-time water level of the reactor pool reaches the full water level; if yes, performing alarm action test.

2. The refueling after major maintenance loop filling method for nuclear power units as claimed in claim 1, characterized in that, The pre-filling preparation comprises: before water is fed into the primary loop, filling the concentrated boric acid injection tank; after the filling of the concentrated boric acid injection tank is completed, performing filling and degassing work preparation of the safety injection pipeline flowmeter.

3. The refueling water charging method for a nuclear power plant according to Claim 2, wherein The filling of the concentrated boric acid injection tank before water is fed into the primary loop comprises: before water is fed into the primary loop, filling the concentrated boric acid injection tank through the direct boronization pipeline.

4. The refueling water charging method for a nuclear power plant according to Claim 2, wherein The filling and degassing work preparation of the safety injection pipeline flowmeter after the filling of the concentrated boric acid injection tank is completed comprises: after the filling of the concentrated boric acid injection tank is completed, filling all the safety injection pipelines in the reactor safety injection system through the direct boronization pipeline.

5. The refueling loop fill method for a nuclear power plant as set forth in claim 1, wherein, The method further comprises: during the filling of all the safety injection pipelines, monitoring the flow information of all the safety injection pipelines in real time; judging whether the safety injection pipelines are filled according to the flow information; if all the safety injection pipelines are filled, determining that the preparation is completed; if any one or more of the safety injection pipelines is not filled, continuing to fill the safety injection pipelines that are not filled until they are filled.

6. The refueling loop fill method for a nuclear power plant as set forth in claim 1, wherein, The filling of the primary loop according to the preset filling mode after the performance test on the low-pressure safety injection pump is completed comprises: after the performance test on the low-pressure safety injection pump is completed, keeping one low-pressure safety injection pump running without stopping the pump; filling the primary loop based on the low-pressure safety injection pump; monitoring the water level of the primary loop in real time; judging whether the real-time water level of the reactor pool reaches the preset water level; if yes, switching to bypass to fill the primary loop.

7. The refueling loop fill method for a nuclear power plant as set forth in claim 6, wherein, The filling of the primary loop based on the low-pressure safety injection pump comprises: filling the primary loop based on the low-pressure safety injection pump in a double-end injection mode.

8. The refueling loop fill method for nuclear power plant units according to claim 1, characterized in that, The method further comprises: alternately starting and stopping the high-pressure safety injection pump during the performance test on the high-pressure safety injection pump; alternately starting and stopping the low-pressure safety injection pump during the performance test on the low-pressure safety injection pump.

9. A refueling after major maintenance primary circuit charging system for a nuclear power plant, characterized in that, comprise: an execution unit configured to perform pre-filling preparation; a first test unit configured to, after the preparation is completed, perform switch operation test on the actuator to be tested and filling and degassing work of the flowmeter; a second test unit configured to, after the switch operation test on the actuator to be tested is completed, perform performance test on the high-pressure safety injection pump; a third test unit configured to, after the performance test on the high-pressure safety injection pump is completed, perform performance test on the low-pressure safety injection pump; a filling unit configured to, after the performance test on the low-pressure safety injection pump is completed, fill the primary loop according to a preset filling mode; a judging unit configured to judge whether the real-time water level of the reactor pool reaches the full water level; The alarm test unit is used to perform alarm action test when the water level in the primary loop reaches the full water level.

10. The refueling after reactor vessel refueling water storage system of claim 9, wherein, The execution unit comprises: The water filling module is used to fill the concentrated boric acid injection tank with water before water is fed into the primary loop; The exhaust work preparation module is used to perform exhaust work preparation for the injection pipeline flowmeter after the water filling of the concentrated boric acid injection tank is completed.

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