A primary circuit drainage system and method for a reactor device of a pressurized water reactor nuclear power plant

Abstract

The present application is dedicated to providing a primary circuit drainage system and method for a reactor device of a pressurized water reactor nuclear power plant, wherein the primary circuit drainage system of the reactor device of the pressurized water reactor nuclear power plant comprises a primary circuit, a coolant outlet pump and a coolant storage tank. The inlet of the coolant outlet pump is connected to the primary circuit drain port through the reactor plant equipment drain header, and the outlet of the coolant outlet pump is connected to the coolant storage tank. The present application solves the technical problem that the drainage operation before the existing primary circuit unsealing has a long overhaul period due to low flow and slow drainage speed by connecting the coolant outlet pump between the primary circuit drain port and the coolant storage tank.

Description

Technical Field

[0001] The present application belongs to the technical field of operation commissioning and overhaul management of nuclear power plants, and specifically relates to a primary-loop drainage system and method for a reactor device of a pressurized water reactor nuclear power plant. Background Art

[0002] During the operation, commissioning and overhaul of the reactor unit of a pressurized water reactor nuclear power plant, the liquid level raising and lowering operations of the primary circuit are often carried out according to the needs of maintenance and other work.

[0003] For example, refer to Figure 1 In the past, the drainage operation before the first circuit was unsealed was first discharged through the reactor building equipment drain tank, and then discharged to the coolant storage tank through the reactor building equipment drain system pump. However, the reactor building equipment drain tank has a small capacity of only 5m 3 The operator needs to pulse open the drainage electric valve to adjust the flow rate to match the drainage capacity of the pump. The electric valve is used for throttling for a long time, which may cause valve damage. The drainage operation before the first circuit is unsealed is carried out through the reactor plant equipment drainage system pump, and the flow rate is limited to about 20m 3 / h, the lower the flow rate, the slower the drainage speed, resulting in a longer overhaul period. In addition, it is difficult to drain water at the maximum flow rate while ensuring that the reactor building equipment drain tank does not overflow. Summary of the invention

[0004] In view of this, the present application is dedicated to providing a primary-loop drainage system and method for a reactor device of a pressurized water reactor nuclear power plant, which solves the technical problem that the existing primary-loop drainage operation before unsealing causes a long overhaul period due to low flow and slow drainage speed by connecting the coolant outlet pump between the primary-loop drain port and the coolant storage tank.

[0005] The first aspect of the present application provides a primary circuit drainage system of a reactor device of a pressurized water reactor nuclear power plant, the primary circuit drainage system of the reactor device of the pressurized water reactor nuclear power plant comprises a primary circuit, a coolant outlet pump and a coolant storage tank. The inlet of the coolant outlet pump is connected to the primary circuit drain port through a reactor plant equipment drain header, and the outlet of the coolant outlet pump is connected to the coolant storage tank.

[0006] In a specific embodiment of the present application, the flow rate of the coolant outlet pump is 60m 3 / h.

[0007] In one specific embodiment of the present application, the volume of the coolant storage tank is 780m 3 .

[0008] In a specific embodiment of the present application, the primary drainage system of the pressurized water reactor nuclear power plant reactor device is suitable for a VVER1200 unit.

[0009] In a specific embodiment of the present application, the primary circuit drainage system of the reactor device of the pressurized water reactor nuclear power plant further includes a first electric valve. The first electric valve is installed between the primary circuit drainage port and the inlet of the coolant outlet pump.

[0010] In a specific embodiment of the present application, the primary drainage system of the reactor device of the pressurized water reactor nuclear power plant also includes a second electric valve and a reactor plant equipment drain tank connected in sequence from the primary drainage port. The pipeline where the second electric valve and the reactor plant equipment drain tank are located is connected in parallel with the pipeline where the coolant outlet pump is located.

[0011] A second aspect of the present application provides a method for draining a single circuit of a reactor unit of a pressurized water reactor nuclear power plant, the method comprising: opening one or more electric drain valves of a single circuit transition section; starting a coolant outlet pump in a single circuit drainage system of a reactor unit of a pressurized water reactor nuclear power plant provided in an embodiment of the present application to discharge the coolant of the single circuit transition section directly into a coolant storage tank, during which the drainage flow is controlled by an electric regulating valve at the outlet of the coolant outlet pump.

[0012] In a specific embodiment of the present application, if the primary drainage system of the pressurized water reactor nuclear power plant reactor unit also includes a first electric valve and a second electric valve, before opening one or more electric drain valves in a primary transition section, the primary drainage method of the pressurized water reactor nuclear power plant reactor unit also includes: opening the first electric valve and closing the second electric valve to transfer the reactor building equipment drain system header to the coolant outlet pump inlet.

[0013] The beneficial effects of the technical solution of the present application are: through the drainage operation before the unsealing of the first circuit, the reactor plant equipment drain manifold is switched to the inlet of the coolant export pump, and the drainage flow and speed can be greatly increased by using the coolant export pump to drain water; the drainage flow is adjusted by the outlet electric regulating valve of the coolant export pump, avoiding the situation where the electric valve is used as a regulating valve, and reducing the possibility of valve failure; the outlet of the coolant export pump goes directly to the coolant storage tank, the volume of which is much larger than the reactor plant equipment drain tank, which simplifies the first circuit drainage process and reduces the operating burden of personnel. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 Shown is a schematic structural diagram of a primary drainage system of a reactor unit in a pressurized water reactor nuclear power plant.

[0015] Figure 2 Shown is a structural schematic diagram of a primary-loop drainage system of a pressurized water reactor nuclear power plant reactor device provided by an embodiment of the present application.

[0016] Figure 3Shown is a structural schematic diagram of a primary-loop drainage system of a pressurized water reactor nuclear power plant reactor device provided by another embodiment of the present application. DETAILED DESCRIPTION

[0017] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0018] At least one embodiment of the present application provides a primary drainage system of a pressurized water reactor nuclear power plant reactor device, referring to Figure 2 The primary drainage system of the reactor device of the pressurized water reactor nuclear power plant includes a primary circuit, a coolant outlet pump and a coolant storage tank. The inlet of the coolant outlet pump is connected to the primary drainage port through the reactor plant equipment drain header, and the outlet of the coolant outlet pump is connected to the coolant storage tank.

[0019] According to the technical solution provided in the embodiment of the present application, the drainage operation before the first-loop unsealing is performed, and the reactor building equipment drain manifold is switched to the inlet of the coolant export pump. The drainage flow and speed can be greatly increased by using the coolant export pump to drain water; the drainage flow is adjusted by the outlet electric regulating valve of the coolant export pump, thereby avoiding the situation where the electric valve is used as a regulating valve and reducing the possibility of valve failure; the outlet of the coolant export pump goes directly to the coolant storage tank, and the volume is much larger than the reactor building equipment drain tank, which simplifies the first-loop drainage process and reduces the operating burden of personnel.

[0020] In at least one embodiment of the present application, the flow rate of the coolant outlet pump is 60m 3 In this way, the drainage rate of a circuit can be increased to a maximum of 60 cubic meters per hour, which simplifies the operation of personnel, avoids the risk of damage caused by the electric valve being used as a regulating valve, and is conducive to shortening the overhaul period.

[0021] The volume of the coolant storage tank can be set according to actual needs, and the present application embodiment does not specifically limit this. For example, in at least one embodiment of the present application, the volume of the coolant storage tank is 780m 3 . refer to Figure 3 The coolant storage tank can be composed of two 390m 3 composition.

[0022] In at least one embodiment of the present application, the primary drainage system of the pressurized water reactor nuclear power plant reactor device is suitable for a VVER1200 unit.

[0023] In at least one embodiment of the present application, the primary drainage system of the pressurized water reactor nuclear power plant reactor device further includes a first electric valve. The first electric valve is installed between the primary drainage port and the inlet of the coolant outlet pump. In this way, the drainage channel of the pipeline where the coolant outlet pump is located can be opened or closed according to actual needs.

[0024] In at least one embodiment of the present application, reference Figure 3 The primary drainage system of the reactor device of the pressurized water reactor nuclear power plant also includes a second electric valve and a reactor plant equipment drain tank connected in sequence from the primary drainage port. The pipeline where the second electric valve and the reactor plant equipment drain tank are located is connected in parallel with the pipeline where the coolant outlet pump is located. In this way, different pipelines can be selected for drainage according to actual drainage needs.

[0025] If the primary drainage system of the reactor device of the pressurized water reactor nuclear power plant also includes a first electric valve, the pipeline where the second electric valve and the reactor plant equipment drain tank are located is connected in parallel with the pipeline where the first electric valve and the coolant outlet pump are located.

[0026] At least one embodiment of the present application provides a primary-loop drainage method for a reactor device of a pressurized water reactor nuclear power plant. The primary-loop drainage method for a reactor device of a pressurized water reactor nuclear power plant includes the following steps.

[0027] S10: Open one or more electric steam traps in a transition section of a circuit.

[0028] S20: Start the coolant outlet pump in the primary drainage system of the pressurized water reactor nuclear power plant reactor device provided in the embodiment of the present application to discharge the coolant in the primary transition section directly into the coolant storage tank, during which the drainage flow rate is controlled by the coolant outlet electric regulating valve.

[0029] In at least one embodiment of the present application, if the primary drainage system of the pressurized water reactor nuclear power plant reactor device further includes a first electric valve and a second electric valve, then before the above S10, the primary drainage method of the pressurized water reactor nuclear power plant reactor device further includes S1.

[0030] S1: Open the first electric valve and close the second electric valve to transfer the reactor building equipment drain system header to the coolant outlet pump inlet.

[0031] The primary drainage method of the pressurized water reactor nuclear power plant reactor device is the corresponding method of use of the primary drainage system of the pressurized water reactor nuclear power plant reactor device provided in the above-mentioned embodiment of the present application, includes corresponding technical features, achieves corresponding technical effects, and will not be repeated here.

[0032] It should be noted that the combination of the various technical features in the embodiments of the present application is not limited to the combination described in the embodiments of the present application or the combination described in the specific embodiments, and all technical features described in the present application can be freely combined or combined in any way unless there is a contradiction between them.

[0033] As shown in this application and claims, unless the context clearly indicates an exception, the words "a", "an" and / or "the" do not refer to the singular and may also include the plural. Generally speaking, the term "comprising" only indicates that the steps and elements that have been clearly identified are included, and these steps and elements do not constitute an exclusive list. The method or device may also include other steps or elements.

[0034] The terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features.

[0035] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A primary drainage system for a reactor unit of a pressurized water reactor nuclear power plant, characterized in that: It includes a primary circuit, a coolant delivery pump and a coolant storage tank. The inlet of the coolant outlet pump is connected to the primary circuit drain outlet through the reactor plant equipment drain header, and the outlet of the coolant outlet pump is connected to the coolant storage tank.

2. A primary drainage system for a pressurized water reactor nuclear power plant reactor device according to claim 1, characterized in that: The flow rate of the coolant outlet pump is 60m 3 / h.

3. The primary drainage system of a pressurized water reactor nuclear power plant reactor device according to claim 1, characterized in that: The volume of the coolant storage tank is 780m 3 .

4. The primary drainage system of a pressurized water reactor nuclear power plant reactor device according to claim 1, characterized in that: The primary drainage system of the reactor unit of a pressurized water reactor nuclear power plant is suitable for VVER1200 units.

5. The primary drainage system of a pressurized water reactor nuclear power plant reactor device according to claim 1, characterized in that: Also includes a first electric valve, The first electric valve is installed between a drain port of a circuit and an inlet of a coolant outlet pump.

6. A primary drainage system for a pressurized water reactor nuclear power plant reactor device according to any one of claims 1 to 5, characterized in that: It also includes a second electric valve and a reactor building equipment drain tank connected in sequence from the primary circuit drain port. Among them, the pipeline where the second electric valve and the reactor plant equipment drain tank are located is connected in parallel with the pipeline where the coolant outlet pump is located.

7. A primary circuit drainage method for a pressurized water reactor nuclear power plant reactor device, characterized in that: include: Open one or more electric steam traps in a transition section of a circuit; Start the coolant outlet pump in the primary drainage system of the pressurized water reactor nuclear power plant reactor device as described in any one of claims 1 to 6 to discharge the coolant in the primary transition section directly into the coolant storage tank, during which the drainage flow rate is controlled by the coolant outlet electric regulating valve.

8. A primary circuit drainage method for a pressurized water reactor nuclear power plant reactor device according to claim 7, characterized in that: If the primary drainage system of the reactor device of a pressurized water reactor nuclear power plant further includes a first electric valve and a second electric valve, before opening one or more electric drain valves of the primary transition section, the primary drainage method of the reactor device of a pressurized water reactor nuclear power plant further includes: Open the first electric valve and close the second electric valve to transfer the reactor building equipment drain system header to the coolant outlet pump inlet.

Images