Nanofiltration silicon removal purification system for boric acid water of nuclear power plant
By installing a detachable nanofiltration membrane silicon removal device at the bottom of the fuel building of a nuclear power plant, multiple systems can share boric acid water for silicon removal, which solves the problems of silicon deposition and high procurement costs, and reduces risks and costs.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-21
- Publication Date
- 2026-03-20
AI Technical Summary
In existing technologies, silicon elements are prone to deposition in boric acid water in nuclear power plants, which affects the integrity of fuel cladding and results in high procurement costs. In addition, nanofiltration membrane silicon removal devices have complex structures, are dangerous to disassemble and assemble, and are not economically viable.
A nanofiltration silica removal purification system for boric acid water in nuclear power plants is designed. A detachable nanofiltration membrane silica removal device is installed on the bottom floor of the fuel plant, and boric acid water from multiple systems is transported to this device for silica removal. The systems share a single device, enabling multi-system operation.
This technology enables multiple systems to share nanofiltration membranes for silicon removal, reducing equipment investment costs, minimizing the risk of radiation exposure for staff, and ensuring that water quality meets system requirements.
Smart Images
Figure CN224020454U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of water chemistry control technology in nuclear power plants, and in particular to a boric acid water nanofiltration purification system for removing silicon in nuclear power plants. Background Technology
[0002] Silicon in boric acid water can form silicates with zeolite elements (calcium, magnesium, aluminum). Many silicates have negative temperature solubility coefficients and tend to deposit at high temperatures. Therefore, silicon is easily deposited on the surface of the fuel cladding in the reactor coolant system (RCP), affecting heat transfer and posing a potential threat to the integrity of the fuel cladding.
[0003] High silicon content in borate systems is a common problem in pressurized water reactor (PWR) nuclear power plants. Besides the Regenerative Potential Reactor (RCP) system, other borate systems prone to high silicon levels include the Safety Injection System (RIS), Reactor Pool and Fuel Pool Cooling and Treatment System (PTR), Reactor Boron and Water Makeup System (REA), and Containment Heat Removal System (EHR). Silicon from the borate in the RIS, PTR, REA, and EHR systems can enter the RCP system, adversely affecting the normal operation of the nuclear power unit.
[0004] Nanofiltration membrane desilication technology is an effective solution for removing silicon from boric acid water and has been applied in several nuclear power plants. However, due to the complex structure of nanofiltration membrane desilication devices and their radioactivity after use, disassembly, assembly, and transportation are labor-intensive, and the risk of radioactive contamination to workers is high. Therefore, it is practically difficult for different nuclear power plant units' RCP, PTR, RIS, and REA systems to share the same equipment. Furthermore, the high purchase price of nanofiltration membrane desilication devices means that purchasing one for each nuclear power unit would be economically unfeasible. Utility Model Content
[0005] The technical problem to be solved by this utility model is to provide a boric acid water nanofiltration purification system for nuclear power plants that can be used by multiple systems.
[0006] The technical solution adopted by this utility model to solve its technical problem is: to provide a nuclear power plant boric acid water nanofiltration silicon removal purification system, including a PTR system purification circuit, a nanofiltration membrane silicon removal device installed on the bottom floor of the fuel plant, and a loading well or transfer well of the PTR system;
[0007] The loading well or transfer well is connected to the PTR system purification loop; the PTR system purification loop is connected to the nanofiltration membrane desiliconization device to transport the desiliconized boric acid water from at least one of the following: containment refueling tank, spent fuel pool, reactor pool, IVR tank, the loading well or transfer well, REA boric acid storage tank, and RCP primary loop to the nanofiltration membrane desiliconization device, and the desiliconized boric acid water is returned through the PTR system purification loop.
[0008] In some embodiments, the nanofiltration membrane silicon removal device is detachably mounted on the ground floor of the fuel plant by bolts, and is located at a height lower than that of the refueling tank inside the containment.
[0009] In some embodiments, the PTR system purification circuit includes a PTR purification pump.
[0010] In some embodiments, the nuclear power plant boric acid water nanofiltration silica removal purification system further includes an in-containment replacement refrigerant tank, which is connected to the PTR system purification loop through RIS system pipelines, EHR system pipelines and RCV system pipelines to form an in-containment replacement refrigerant tank boric acid water silica removal loop.
[0011] In some embodiments, the boric acid water nanofiltration silica removal purification system of the nuclear power plant further includes an IVR water tank, which is connected to the PTR system purification loop through an EHR system pipeline to form an IVR water tank boric acid water silica removal loop.
[0012] In some embodiments, the nuclear power plant boric acid water nanofiltration desiliconization purification system further includes an REA boric acid storage tank. The REA boric acid storage tank is connected to the loading well or transfer well through REA system pipelines and PTR system pipelines, so that the boric acid water in the REA boric acid storage tank is mixed with the demineralized water of the TEP system before entering the loading well or transfer well. The desiliconized boric acid water is recycled and returned through the TEP system.
[0013] In some embodiments, the nuclear power plant boric acid water nanofiltration silicon removal purification system further includes an RCP primary loop, which is connected to the reactor water pool and connected to the PTR system purification loop through the reactor water pool, forming an RCP primary loop boric acid water silicon removal loop.
[0014] In some embodiments, the nuclear power plant boric acid water nanofiltration silica removal purification system further includes an in-containment refueling tank, a spent fuel pool, a reactor pool, an IVR tank, the loading well or transfer well, an REA boric acid storage tank, and an RCP primary loop; the in-containment refueling tank, the spent fuel pool, the reactor pool, the IVR tank, the loading well or transfer well, and the RCP primary loop are respectively connected to the nanofiltration membrane silica removal device through the PTR system purification loop; the REA boric acid storage tank is connected to the PTR system purification loop through the loading well or transfer well.
[0015] In some embodiments, the containment refueling tank, spent fuel pool, reactor pool, IVR tank, loading or transfer well, REA boric acid storage tank, and RCP primary loop all belong to the same nuclear power unit.
[0016] In some embodiments, the containment refueling tank, spent fuel pool, reactor pool, IVR tank, loading or transfer well, REA boric acid storage tank, and RCP primary loop all belong to the same nuclear power unit.
[0017] The boric acid water nanofiltration silica removal purification system of the nuclear power plant also includes an additional pipeline or a common pipeline, which is connected between the loading well or transfer well and the containment refueling tank, spent fuel pool, reactor pool, IVR tank, loading well or transfer well, REA boric acid storage tank and RCP primary loop of another nuclear power unit; the common pipeline is the TER system pipeline.
[0018] The beneficial effects of this utility model are: to realize the use of a nanofiltration membrane desiliconization device for multiple systems in nuclear power units, only requiring the online transmission of boric acid water to the nanofiltration membrane desiliconization device through the system, or indirectly introducing boric acid water into the loading well or transfer well of the PTR system and then transmitting it to the nanofiltration membrane desiliconization device. The boric acid water transmission process does not affect the normal function of the system in which the transmission pipeline is located. The desiliconized boric acid water can be returned to the original system without water pollution, and can still meet the water quality requirements of the original system. Attached Figure Description
[0019] The present invention will be further described below with reference to the accompanying drawings and embodiments. In the accompanying drawings:
[0020] Figure 1 This is a logic connection diagram of a nuclear power plant boric acid water nanofiltration silicon removal purification system according to an embodiment of this utility model. Detailed Implementation
[0021] To provide a clearer understanding of the technical features, objectives, and effects of this utility model, the specific embodiments of this utility model will now be described in detail with reference to the accompanying drawings.
[0022] refer to Figure 1 An embodiment of the present invention provides a nuclear power plant boric acid water nanofiltration silicon removal purification system, which includes a PTR system purification circuit, a nanofiltration membrane silicon removal device installed on the bottom floor of the fuel plant, and a loading well or transfer well of the PTR system.
[0023] The loading or transfer well is connected to the PTR system purification loop; the PTR system purification loop is connected to the nanofiltration membrane desiliconization unit, thereby enabling the desiliconization of boric acid water from at least one of the following: containment refueling tank, spent fuel pool, reactor pool, IVR tank, loading or transfer well, REA boric acid storage tank, and RCP primary loop, to be transported to the nanofiltration membrane desiliconization unit. The desiliconized boric acid water is returned through the PTR system purification loop, realizing the desiliconization of boric acid water from multiple systems of the nuclear power unit with one nanofiltration membrane desiliconization unit. This not only solves the problem of high silicon content in boric acid water of nuclear power units, but also achieves the purpose of sharing, eliminating the need to purchase multiple nanofiltration membrane desiliconization units for multiple systems, reducing equipment investment costs, and achieving high economic efficiency.
[0024] The nanofiltration membrane desiliconization unit can be detachably installed on the ground floor of the fuel building using bolts. Sufficient height difference exists between the nanofiltration membrane desiliconization unit and the IRWST (In-Containment Refill Tank), spent fuel pool, reactor pool, loading shaft, and transfer shaft of the nuclear power unit, allowing desiliconized boric acid water to flow into the nanofiltration membrane desiliconization unit by gravity. Among the IRWST, spent fuel pool, reactor pool, loading shaft, and transfer shaft, the IRWST is the lowest. Therefore, by setting the height of the nanofiltration membrane desiliconization unit lower than that of the IRWST, spent fuel pool, reactor pool, loading shaft, and transfer shaft, the nanofiltration membrane desiliconization unit can be simultaneously positioned lower than the IRWST, spent fuel pool, reactor pool, loading shaft, and transfer shaft.
[0025] For example, in nuclear power units, the IRWST is typically located at a height of -5m in the fuel building. In this case, the nanofiltration membrane desiliconization device can be installed at a position below -5m in the fuel building, such as -10m.
[0026] In some embodiments, the boric acid water nanofiltration desiliconization purification system of a nuclear power plant further includes at least one of the following: a containment refueling tank, a spent fuel pool, a reactor pool, an IVR tank, a loading well or transfer well, an REA boric acid storage tank, and an RCP primary loop; the containment refueling tank, spent fuel pool, reactor pool, IVR tank, loading well or transfer well, REA boric acid storage tank, and RCP primary loop belong to the same nuclear power unit. The containment refueling tank, spent fuel pool, reactor pool, IVR tank, loading well or transfer well, and RCP primary loop are each connected to the nanofiltration membrane desiliconization device through a PTR system purification loop; wherein, the REA boric acid storage tank is connected to the loading well or transfer well through REA system pipelines and PTR system pipelines, and the desiliconized boric acid water is recycled and returned through the TEP system (coolant storage and treatment system).
[0027] The nanofiltration membrane silicon removal device can be implemented using existing technology. For example, a nanofiltration membrane silicon removal device includes a buffer tank and a nanofiltration tank. The nanofiltration tank is equipped with a nanofiltration membrane. One or more nanofiltration tanks can be set up as needed to achieve primary nanofiltration, secondary nanofiltration, etc.
[0028] The concentrated wastewater discharge line of the nanofiltration membrane desiliconization unit can be connected to the nuclear island exhaust and drainage system (RPE), and the demineralized water supply line of the nanofiltration membrane desiliconization unit is connected to the nuclear island demineralized water distribution system (SED). The nanofiltration membrane desiliconization unit is connected to the PTR, SED, and RPE systems via flanges or hoses, and can be disconnected or reconnected as needed. The outlet of the nanofiltration membrane desiliconization unit's water collection pan drain faces the RPE floor drain; in the event of an accidental leak in the nanofiltration membrane desiliconization unit, the leaked wastewater is discharged into the RPE system.
[0029] The present invention will be further described below through specific embodiments.
[0030] Example 1: Silicon removal and purification of the In-Containment Replacement Water Tank (IRWST)
[0031] The In-Retention Water Tank (IRWST) is a concrete-lined stainless steel tank belonging to the RIS system. Located at the bottom of the reactor building, it is arranged in a double-ring configuration between the containment crater and the inner containment vessel. The IRWST contains boric acid solution, used for filling the reactor pool during normal refueling and for providing water to the low-pressure injection (LSI) or containment spray systems during accidents. The total water capacity of the IRWST and the In-Retention Water Vessel (IVR) tanks in the EHR system meets the water requirements for reactor shutdown and refueling, as well as the water requirements of the RIS and EHR systems during accidents. To ensure the normal operation of the RIS and EHR system pumps after an accident, the IRWST is equipped with a filtration system to intercept and filter debris entering the IRWST. In addition to the RIS and EHR systems, the RCV and PTR systems can also draw water from the IRWST (via the EHR system's intake line).
[0032] The IRWST is connected to the PTR system purification loop via RIS, EHR, and RCV system pipelines, forming a boric acid water desilication loop within the containment refueling tank. When the IRWST's boric acid water needs desilication, it enters the PTR system purification loop via the RIS, EHR, and RCV system pipelines, then enters the nanofiltration membrane desilication unit for purification, and finally returns to the IRWST via the PTR and RIS system pipelines.
[0033] The PTR system's purification loop is equipped with a PTR purification pump. When using a nanofiltration membrane desiliconization device to remove silica from IRWST, the PTR purification pump can be activated to increase the turbidity of the IRWST. Alternatively, the PTR purification pump can be left off, in which case the IRWST boric acid solution circulates under the power of gravity and the pump itself provided by the nanofiltration membrane desiliconization device.
[0034] The PTR system's purification loop is specifically divided into a spent fuel pool purification loop and a reactor pool purification loop. The nanofiltration membrane silicate removal unit is mainly installed on the reactor pool purification loop; that is, the boric acid water from the IRWST enters the nanofiltration membrane silicate removal unit through the reactor pool purification loop. When the nanofiltration membrane silicate removal unit is used for IRWST silicate removal, the PTR system's spent fuel pool purification loop can operate normally to purify the spent fuel pool, unaffected by IRWST silicate removal. The boric acid water purified by the nanofiltration membrane silicate removal unit can be introduced into the PTR system's desalination bed purification unit for further purification, and then returned to the IRWST. During this time, the PTR system's spent fuel pool purification is suspended.
[0035] The spent fuel water tank purification loop of the PTR system can also serve as a water inlet line to introduce IRWST boric acid water into the nanofiltration membrane desiliconization unit for purification. To promote turbidity in the IRWST water tank, the RIS system safety injection pump and the EHR system containment heat removal pump can be started to turbid the IRWST water tank when the nanofiltration membrane desiliconization unit is purifying IRWST.
[0036] The PTR purification pump in the reactor pool purification loop can operate normally during both startup and shutdown of the nanofiltration membrane silicon removal device. The heat emitted by the nanofiltration membrane silicon removal device during operation will not cause significant changes in the ambient temperature of the room.
[0037] Example 2: Silicon removal and purification of spent fuel water tank in PTR system
[0038] The spent fuel pool in the PTR system is mainly used to store spent fuel during the decay process and new fuel before it is loaded into the reactor core. When the spent fuel pool requires desiliconization, the boric acid water in the spent fuel pool is directly purified through the PTR purification loop into the nanofiltration membrane desiliconization unit, and then returned to the spent fuel pool through the PTR system pipeline.
[0039] When using a nanofiltration membrane desiliconization unit to remove silica from a spent fuel water tank, the PTR purification pump can be started to increase the turbidity of the spent fuel water tank. Alternatively, the PTR purification pump can be left off, in which case the boric acid water in the spent fuel water tank is circulated by gravity and the pumps provided by the nanofiltration membrane desiliconization unit itself.
[0040] The boric acid water purified by the nanofiltration membrane desiliconization device can be introduced into the PTR system desalination bed purification unit for further purification before being returned to the spent fuel water pool.
[0041] Example 3: Silicon Removal and Purification in IVR Water Tanks
[0042] The IVR tank is used for early-stage reactor pit filling following a severe accident. It serves as a water source for filling the reactor pool and is part of the EHR system. The IVR tank is located in the reactor building and has a concrete-lined, stainless steel-lined structure.
[0043] The IVR water tank is connected to the PTR system purification loop via the EHR system pipeline, forming the IVR water tank boric acid water desiliconization loop. When the IVR water tank needs desiliconization, the boric acid water in the IVR water tank enters the PTR system purification loop through the EHR system pipeline, then enters the nanofiltration membrane desiliconization device for purification, and after purification, returns to the IVR water tank through the PTR system pipeline and the EHR system pipeline.
[0044] When using a nanofiltration membrane desiliconization device to remove silica from an IVR water tank, the PTR purification pump can be activated to increase the turbidity of the IVR water tank. Alternatively, the PTR purification pump can be deactivated, in which case the boric acid solution in the IVR water tank circulates under gravity and powered by the pump integrated into the nanofiltration membrane desiliconization device itself.
[0045] The PTR system's purification loop is specifically divided into a spent fuel pool purification loop and a reactor pool purification loop. The nanofiltration membrane silicate removal unit is mainly installed on the reactor pool purification loop; that is, the boric acid water from the IVR tank enters the nanofiltration membrane silicate removal unit through the reactor pool purification loop. When the IVR tank is being silicate removed, the PTR system's spent fuel pool purification loop can operate normally to purify the spent fuel pool, unaffected by the IVR tank silicate removal. The boric acid water purified by the nanofiltration membrane silicate removal unit can be introduced into the PTR system's desalination bed purification unit for further purification before returning to the IVR tank. During this time, the PTR system's spent fuel pool purification is suspended.
[0046] Example 4: Silicon removal and purification of loading or transfer wells in PTR systems
[0047] Fuel assemblies are loaded into transport containers in the loading well of the PTR system and transported off-site. The transfer well, located between the spent fuel water pool and the transfer channel, serves as the fuel transfer route. The loading and transfer wells of the PTR system can temporarily store a certain amount of boric acid water for the REA, EHR, and RIS systems.
[0048] When the loading well or transfer well of the PTR system needs desiliconization, the boric acid water from the loading well or transfer well enters the nanofiltration membrane desiliconization device directly through the PTR purification loop for purification, and then returns to the loading well or transfer well through the PTR system pipeline.
[0049] When using a nanofiltration membrane desiliconization unit to remove silica from the loading or transfer well of a PTR system, the PTR purification pump can be started to increase the turbidity of the loading or transfer well. Alternatively, the PTR purification pump can be left off, in which case the boric acid solution in the loading or transfer well circulates under gravity and powered by the pump provided by the nanofiltration membrane desiliconization unit itself.
[0050] When using a nanofiltration membrane desiliconization unit to remove silica from the loading or transfer well, the spent fuel water pool purification circuit is occupied, and the spent fuel water pool purification of the PTR system is suspended. The boric acid water purified by the nanofiltration membrane desiliconization unit can be introduced into the PTR system's desalination bed purification unit for further purification before being returned to the loading or transfer well.
[0051] Example 5: Silicon removal and purification in reactor pools
[0052] The reactor pool is part of the PTR system. When the unit is shut down, the reactor pool is filled with boric acid water for the transfer and temporary storage of fuel assemblies or in-core components. When the boric acid water in the reactor pool needs to be desiliconized, it enters the nanofiltration membrane desiliconization unit directly through the PTR purification loop (specifically the reactor pool purification loop) for purification. After purification, it returns to the reactor pool through the PTR system pipeline.
[0053] When removing silica from the reactor pool, the PTR purge pump can be activated to increase the turbidity of the reactor pool. Alternatively, the PTR purge pump can be deactivated, in which case the boric acid solution in the reactor pool is circulated by gravity and the pumps provided by the nanofiltration membrane silica removal unit itself.
[0054] During silicon removal from the reactor pool, the spent fuel pool purification loop of the PTR system can operate normally to purify the spent fuel pool, unaffected by silicon removal from the reactor pool. Boric acid water purified by the nanofiltration membrane silicon removal unit can be introduced into the desalination bed purification unit of the PTR system for further purification before being returned to the reactor pool. During this time, the spent fuel pool purification process of the PTR system is suspended.
[0055] Example 6: Silicon removal and purification in REA boric acid storage tank
[0056] The REA boric acid storage tank stores all the boric acid required for reactivity control during normal unit operation. During normal unit operation, the REA boric acid storage tank is nearly full at the end of each fuel cycle. When the RCP reaches the refueling shutdown boron concentration and the pressurizer is full, the boric acid storage tank level reaches its minimum value. At this point, the remaining boric acid capacity should be sufficient to bring the unit from startup to full power immediately back to cold shutdown.
[0057] The REA boric acid storage tank belongs to the REA system (reactor boron and water supply system). The REA boric acid storage tank is connected to the loading well or transfer well through the REA system pipeline and the PTR system pipeline. The boric acid water in the REA boric acid storage tank is mixed with the demineralized water of the TEP system and then enters the loading well or transfer well.
[0058] When the boric acid solution in the REA boric acid storage tank needs desiliconization, the boric acid solution in the REA boric acid storage tank, driven by the REA boric acid transfer pump, is mixed with the demineralized water from the TEP system through the REA system pipeline (to reduce the boric acid concentration), and then transferred to the loading well or transfer well of the PTR system through the PTR system pipeline. In the loading well or transfer well, the boric acid solution is then directly purified by the nanofiltration membrane desiliconization unit through the PTR purification loop. After purification, it is transferred to the TEP system coolant storage tank through the PTR system pipeline and the TEP system pipeline, and then processed by the TEP desalination bed purification unit and evaporation unit before being returned to the REA boric acid storage tank.
[0059] Example 7: RCP primary loop desiliconization and purification
[0060] The primary coolant in the RCP is used to cool the reactor core. Light water in the coolant acts as a neutron moderator and a reflector, while boric acid in the coolant helps regulate reactivity.
[0061] During reactor power operation, the RCP primary coolant cannot be directly transferred to the nanofiltration membrane silicon removal device for purification. At this time, the silicon content is reduced by replacing it with low-silicon-concentration boric acid water in the REA boric acid storage tank. The silicon in the RCP primary coolant will be recovered into the REA boric acid storage tank through the TEP system.
[0062] During the unit overhaul, the RCP primary loop is connected to the reactor pool, thus connecting the RCP primary loop to the PTR system purification loop, forming the RCP primary loop boric acid water desiliconization loop. After the RCP primary loop is connected to the reactor pool, the RCP primary loop coolant (boric acid water) becomes part of the reactor pool boric acid water. It is then sent to the nanofiltration membrane desiliconization unit through the PTR system purification loop for purification and desiliconization, and then returned to the RCP primary loop, thus purifying the RCP primary loop coolant.
[0063] Furthermore, in this invention, when desiliconization is performed on two or more nuclear power units using a nanofiltration membrane desiliconization device, the boric acid water from other units can be temporarily stored in the loading well or transfer well of the PTR system of the unit where the nanofiltration membrane desiliconization device is located, and then transported from the loading well or transfer well to the nanofiltration membrane desiliconization device for desiliconization purification. After the desiliconization is completed, the boric acid water is returned.
[0064] Correspondingly, the boric acid water nanofiltration silica removal purification system of the nuclear power plant also includes additional pipelines or common pipelines, which are connected between the loading well or transfer well and the refueling tank, spent fuel pool, reactor pool, IVR tank, loading well or transfer well, REA boric acid storage tank and RCP primary loop of another nuclear power unit.
[0065] The additional pipelines are temporary connection pipelines, and the common pipelines are TER system pipelines.
[0066] The transfer of boric acid water between different units can be accomplished through additional pipelines or shared pipelines. Typically, the Nuclear Waste Discharge System (TER) is shared by different units, and a portion of the TER system's pipelines can be used as a shared pipeline for the transfer of boric acid water between different units. In this way, a single nanofiltration membrane desiliconization unit can be used for the desiliconization and purification of two or more nuclear power units.
[0067] In addition, nanofiltration membrane silicon removal devices also purify other impurities in the boric acid water of nuclear power plants, such as sodium ions, calcium ions, magnesium ions, aluminum ions, etc., anions (fluoride ions, chloride ions, sulfate ions, etc.), and radioactive activated corrosion products (cobalt-58, cobalt-60, chromium-51, etc.). These anions and cations or activated corrosion products are normally purified by the desalination bed.
[0068] The above description is merely an embodiment of this utility model and does not limit the patent scope of this utility model. Any equivalent structural or procedural transformations made based on the description and drawings of this utility model, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this utility model.
Claims
1. A boric acid water nanofiltration silica removal purification system for nuclear power plants, characterized in that, This includes the PTR system purification circuit, the nanofiltration membrane desiliconization device installed on the ground floor of the fuel plant, and the loading or transfer well of the PTR system; The loading well or transfer well is connected to the PTR system purification loop; the PTR system purification loop is connected to the nanofiltration membrane desiliconization device to transport the desiliconized boric acid water from at least one of the following: containment refueling tank, spent fuel pool, reactor pool, IVR tank, the loading well or transfer well, REA boric acid storage tank, and RCP primary loop to the nanofiltration membrane desiliconization device, and the desiliconized boric acid water is returned through the PTR system purification loop.
2. The boric acid water nanofiltration silica removal purification system for nuclear power plants according to claim 1, characterized in that, The nanofiltration membrane silicon removal device is detachably installed on the bottom floor of the fuel plant by bolts, and its height is lower than that of the refill water tank inside the containment.
3. The boric acid water nanofiltration silica removal purification system for nuclear power plants according to claim 1, characterized in that, The PTR system purification circuit includes a PTR purification pump.
4. The nuclear power plant boric acid water nanofiltration silicon removal purification system according to claim 1, characterized in that, The boric acid water nanofiltration silica removal purification system of the nuclear power plant also includes a displacement tank inside the containment. The displacement tank inside the containment is connected to the PTR system purification loop through RIS system pipelines, EHR system pipelines and RCV system pipelines to form a boric acid water silica removal loop inside the containment.
5. The boric acid water nanofiltration silica removal purification system for nuclear power plants according to claim 1, characterized in that, The boric acid water nanofiltration silica removal purification system of the nuclear power plant also includes an IVR water tank, which is connected to the PTR system purification loop through the EHR system pipeline to form an IVR water tank boric acid water silica removal loop.
6. The boric acid water nanofiltration silica removal purification system for nuclear power plants according to claim 1, characterized in that, The boric acid water nanofiltration desiliconization purification system of the nuclear power plant also includes an REA boric acid storage tank. The REA boric acid storage tank is connected to the loading well or transfer well through the REA system pipeline and the PTR system pipeline, so that the boric acid water in the REA boric acid storage tank is mixed with the demineralized water of the TEP system before entering the loading well or transfer well. The desiliconized boric acid water is recycled and returned through the TEP system.
7. The nuclear power plant boric acid water nanofiltration silica removal purification system according to claim 1, characterized in that, The boric acid water nanofiltration silicon removal purification system of the nuclear power plant also includes an RCP primary loop, which is connected to the reactor pool and then connected to the PTR system purification loop through the reactor pool, forming an RCP primary loop boric acid water silicon removal loop.
8. The nuclear power plant boric acid water nanofiltration silica removal purification system according to any one of claims 1-7, characterized in that, The nuclear power plant boric acid nanofiltration silica removal purification system also includes a containment refueling tank, a spent fuel pool, a reactor pool, an IVR tank, the loading well or transfer well, an REA boric acid storage tank, and an RCP primary loop; the containment refueling tank, the spent fuel pool, the reactor pool, the IVR tank, the loading well or transfer well, and the RCP primary loop are respectively connected to the nanofiltration membrane silica removal device through the PTR system purification loop; the REA boric acid storage tank is connected to the PTR system purification loop through the loading well or transfer well.
9. The boric acid water nanofiltration silica removal purification system for nuclear power plants according to claim 8, characterized in that, The containment refueling tank, spent fuel pool, reactor pool, IVR tank, loading or transfer well, REA boric acid storage tank, and RCP primary loop all belong to the same nuclear power unit.
10. The nuclear power plant boric acid water nanofiltration silica removal purification system according to any one of claims 1-7, characterized in that, The refueling tank, spent fuel pool, reactor pool, IVR tank, loading or transfer well, REA boric acid storage tank, and RCP primary loop all belong to the same nuclear power unit. The boric acid water nanofiltration silica removal purification system of the nuclear power plant also includes an additional pipeline or a common pipeline, which is connected between the loading well or transfer well and the containment refueling tank, spent fuel pool, reactor pool, IVR tank, loading well or transfer well, REA boric acid storage tank and RCP primary loop of another nuclear power unit; the common pipeline is the TER system pipeline.