Spent fuel post-treatment process chemical debugging method

Abstract

The invention belongs to the technical field of power reactor spent fuel post-treatment debugging, and particularly relates to a spent fuel post-treatment process chemical debugging method. The method comprises the following steps: S0, defining chemical test sub-stages: defining the chemical test sub-stages as 50% of chemical test sub-stages and 100% of chemical test sub-stages; the method comprises the following steps: S1, carrying out system acid cleaning in a 50% chemical test sub-stage; s2, carrying out a one-time acid passing test in a 50% chemical test sub-stage; s3, carrying out an acid cycle test of a 50% chemical test sub-stage; s4, carrying out a linkage test of 50% of chemical test sub-stages; and S5, carrying out a linkage test of the 100% chemical test sub-stage. The method can be applied to a post-treatment plant, realizes gradual release of industrial safety risks in a non-radioactive stage of the post-treatment plant, reduces debugging risks and prerequisite conditions on the basis of ensuring test effectiveness and data representativeness, improves debugging flexibility and intensiveness, and improves debugging efficiency. And meanwhile, the effects of reducing rectification difficulty, saving debugging cost, deepening personnel training and the like are achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of power reactor spent fuel post-processing debugging, and in particular relates to a spent fuel post-processing process chemical debugging method. Background Art

[0002] The commissioning of power reactor spent fuel reprocessing is divided into four stages: water test, chemical test, cold uranium test, and thermal test. The task of the chemical test is to use nitric acid solution to replace the water phase flow, 30% TBP-kerosene or kerosene as the organic phase flow, carry out two-phase countercurrent tests on pulse extraction columns and mixed clarification tanks, determine the best operating conditions for each extraction equipment based on phase entrainment and hydraulic parameters, verify the acid mass transfer and oil removal effects, and perform acid cleaning on the system, and calibrate and verify various monitoring parameters such as liquid level, flow, and density.

[0003] The systems mainly involved in chemical experiments include the head end, co-decontamination separation, plutonium purification and plutonium tail end, uranium purification and uranium tail end, high-level waste liquid evaporation, medium- and low-level waste liquid evaporation, contaminated solvent treatment, auxiliary supporting systems, etc. The head end mainly includes shearing (not involved in chemical experiments), acid preparation (through a dissolver, abbreviated as "dissolution"), sedimentation centrifugation, seasoning, precise measurement and other links. Co-decontamination separation mainly includes the first co-extraction of uranium and plutonium (1A unit), uranium-plutonium separation (the first plutonium stripping separates uranium and plutonium, referred to as "1B unit"), the first uranium stripping (1C unit), solvent regeneration and other links. The plutonium purification mainly includes the first co-extraction of uranium and plutonium (1A unit), uranium-plutonium separation (the first plutonium stripping separates uranium and plutonium, referred to as "1B unit"), the first uranium stripping (1C unit), solvent regeneration and other links. It includes the second extraction of plutonium (2A unit), the second stripping of plutonium (2B unit) and other links. The plutonium tail end mainly includes the preparation of the reaction liquid to be precipitated (OF seasoning), precipitation and filtration with oxalic acid (precipitation filtration), destruction of excess oxalic acid in the mother liquor obtained by filtration (mother liquor destruction) and other links. Uranium purification mainly includes the second extraction of uranium (2D unit), the second stripping of uranium (2E unit), the third extraction of uranium (3D unit), the third stripping of uranium (3E unit), corresponding solvent regeneration and evaporator and other links. The uranium tail end mainly includes the evaporator, fluidized bed (not involved in chemical experiments) and other links. The liquid to be extracted in units 1A, 1B, 1C, 2A, 2B, 2D, 2E, 3D, and 3E is collectively referred to as F material, the extractant or stripping agent is collectively referred to as X extractant or X stripping agent, the F material and the X extractant or X stripping agent are subjected to a two-phase countercurrent extraction or stripping process, the aqueous phase obtained after the extraction is collectively referred to as W waste liquid, and the aqueous phase obtained after stripping is collectively referred to as U material or P material.

[0004] The traditional chemical test method is to use nitric acid with the same acidity as normal operation to replace the aqueous phase material, and conduct the test in the order of "system test first, then linkage test". When debugging with the traditional chemical test method, the normal operating acidity of the aqueous phase material can reach up to 11 mol / L. In order to reduce the debugging risks such as acid leakage, equipment corrosion, personnel acid burns, and nitrogen oxide poisoning, it is necessary to first meet the prerequisites such as waste acid denitrification treatment, plant ventilation, and nitrogen oxide tail gas treatment. Therefore, in the traditional debugging sequence arrangement, the human, financial and material resources of construction and debugging have to be dispersed to the above prerequisites, and the resources cannot be concentrated on the post-processing process. In other words, when the above prerequisites are not met, the traditional chemical test cannot start. In addition, in the traditional chemical test method, although the organic phase is set up with a circulation path, nitric acid as the aqueous phase passes through in the order of head end, co-decontamination separation, plutonium purification, plutonium tail end or head end, co-decontamination separation, uranium purification, and uranium tail end at one time, and no circulation path is set. It takes about two months of test cycle to determine the optimal operating conditions, and the cost of reagents represented by nitric acid is relatively high. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a spent fuel reprocessing process chemical debugging method, which can be applied in a reprocessing plant to achieve the gradual release of industrial safety risks in the non-radioactive stage of the reprocessing plant, reduce debugging risks and prerequisites on the basis of ensuring the effectiveness of the test and the representativeness of the data, improve the flexibility and intensiveness of debugging, and at the same time reduce the difficulty of rectification, save debugging costs, and deepen personnel training.

[0006] The technical solution adopted by the present invention is:

[0007] A spent fuel reprocessing process chemical debugging method comprises the following steps:

[0008] S0: Perform the chemical test sub-stage, which is defined as the 50% chemical test sub-stage and the 100% chemical test sub-stage;

[0009] S1: System acid cleaning for 50% chemical test sub-stage

[0010] For one week, the system was soaked and cleaned with 1.5 mol / L nitric acid as the aqueous phase to improve cleanliness. No organic phase was added in this stage. Nitric acid can simultaneously use the aqueous phase path and the organic phase path to maximize the cleaning range.

[0011] S2: Conduct a one-time acid pass test for the 50% chemical test sub-stage

[0012] After S1 is completed, 0.5 mol / L nitric acid is used as the X stripping agent for F material, 1B and 2B units, and 0.01 mol / L nitric acid is used as the X stripping agent for 1C, 2E, and 3E units, but the water phase is not circulated. The system is passed through once to fully replace the waste acid after washing. 30% TBP-kerosene is used as the organic phase, that is, the X extractant. Unlike the water phase, the existing path of the organic phase is used for organic phase circulation in this stage;

[0013] S3: Conduct acid cycle test for 50% chemical test sub-stage

[0014] In two months, 0.5 mol / L nitric acid was used as the X stripping agent for F material, 1B and 2B units, 0.01 mol / L nitric acid was used as the X stripping agent for 1C, 2E and 3E units, and 30% TBP-kerosene was used as the organic phase, i.e., the X extractant. During this stage, the water phase circulation and the organic phase circulation were carried out, and the hydraulic test of each unit extraction equipment was focused on;

[0015] S4: Conduct linkage tests for the 50% chemical test sub-phase

[0016] Over a period of one week, 0.5 mol / L nitric acid was added as the aqueous phase and 30% TBP-kerosene was added as the organic phase. During this stage, the organic phase was circulated but the aqueous phase was not circulated, and the linkage verification of the transport paths between the sub-items was focused.

[0017] S5: Conduct linkage test of 100% chemical test sub-stage

[0018] Over a period of one week, normal operating acidity (up to 11 mol / L) was added as the aqueous phase, and 30% TBP-kerosene was added as the organic phase. During this stage, the organic phase was circulated and the aqueous phase was not circulated. The focus was on verifying the normal operating acidity conditions for the selected operating conditions.

[0019] The S1 specifically includes the following steps:

[0020] S101: 1.5 mol / L nitric acid is prepared at the head end and added to the dissolver to obtain acid solution, and the acid solution is subjected to sedimentation centrifugation, seasoning, and precise metering to achieve acid cleaning of the head end, and the precisely metered acid solution returns to the acid preparation to form an internal circulation path to achieve cyclic cleaning of the head end;

[0021] S102: The 1A unit of co-decontamination separation, plutonium purification, and plutonium tail end can receive the acid solution accurately measured from the head end, or independently add 1.5 mol / L nitric acid, and return to the 1A unit in the order of passing through the 1A unit, 1B unit, 1C unit, and solvent regeneration, or return to the 2A unit in the order of passing through the 1A unit, 1B unit, 2A unit, 2B unit, OF seasoning, precipitation filtration, and mother liquor destruction, so as to realize cyclic cleaning;

[0022] Also includes a supplementary cycle, the supplementary cycle includes the return of the 2B unit to the 1B unit and the return of the solvent to the 2A unit;

[0023] It also includes a sub-item internal cycle, wherein the sub-item internal cycle includes the return of unit 1C to unit 1A and the destruction of mother liquor to unit 2A;

[0024] The cyclic cleaning, supplementary cycle and sub-item internal cycle together realize co-decontamination separation, plutonium purification and cyclic cleaning of the plutonium tail end;

[0025] S103: The 2D unit for uranium purification and uranium tail end can receive nitric acid from the co-decontamination separation 1C unit, or independently add 1.5 mol / L nitric acid, and return to the 2D unit in the order of passing through the 2D unit, the 2E unit, and the solvent regeneration, so as to achieve cyclic cleaning;

[0026] Also includes a sub-item inner loop, the sub-item inner loop includes the 2E unit returning the 2D unit;

[0027] S104: The 3D unit for uranium purification and uranium tail can receive nitric acid from the 2E unit, or independently add 1.5 mol / L nitric acid, and return to the 3D unit in the order of passing through the 3D unit, the 3E unit, and the solvent regeneration, to achieve cyclic cleaning;

[0028] Also included is a sub-item inner loop, the sub-item inner loop including the 3E unit returning to the 3D unit;

[0029] S105: The acid cleaning cycle continues for one week according to the above path. After completion, all the waste acid after cleaning passes through the emptying system of each sub-item, is neutralized by adding alkali, and is discharged as wastewater through the nearest floor drain in the green / orange zone and the sump;

[0030] When the above steps are carried out, the nitric acid stays in each link for more than 2 hours to perform sufficient immersion and cleaning to improve cleanliness.

[0031] The S102 also includes internal unit circulation, which includes utilizing the "W waste liquid reuse as F material" path of the 1A unit and the 2A unit and the "U material reuse as X stripping agent" path of the 1C unit to perform internal unit circulation.

[0032] The S102 also includes internal unit circulation, which utilizes the "W waste liquid reuse as F material" path of the 2D unit and the "U material reuse as X stripping agent" path of the "2E unit" to perform internal unit circulation.

[0033] The S102 also includes internal unit circulation, which includes utilizing the "W waste liquid reuse as F material" path of the 3D unit and the "U material reuse as X stripping agent" path of the 3E unit to perform internal unit circulation.

[0034] The S2 specifically includes the following steps:

[0035] S201: Acid is prepared at the head end, 0.5 mol / L nitric acid is added to the head end to obtain acid solution, and the acid solution is subjected to sedimentation centrifugation, seasoning, precise metering and other steps to achieve one-time acid passage;

[0036] S202: The 1A unit of the co-decontamination separation, plutonium purification, and plutonium tail end can receive the acid solution accurately measured from the head end or independently add 0.5 mol / L nitric acid as the aqueous phase F material, and the F material is extracted by the 1A unit to obtain the aqueous phase W waste liquid, completing a one-time pass without circulation;

[0037] 0.5 mol / L nitric acid is added to the 1B unit independently as the aqueous phase X stripping agent, the X stripping agent is stripped by the 1B unit, and then extracted by the 2A unit to obtain the aqueous phase W waste liquid, completing a one-time pass without circulation;

[0038] 0.01 mol / L nitric acid is independently added to the 1C unit as the aqueous phase X stripping agent, and the X stripping agent is stripped by the 1C unit to obtain the U material, which can be transported to the uranium purification and uranium tail end 2D unit through the inter-sub-item transport path;

[0039] Unit 2A can receive the P material obtained after stripping from unit 1B or the material returned from the destruction of the mother liquor or independently add 0.5 mol / L nitric acid as the aqueous phase F material. The F material is extracted by unit 2A to obtain the aqueous phase W waste liquid, completing a one-time pass without circulation;

[0040] 0.5 mol / L nitric acid is added to the 2B unit independently as the aqueous phase X stripping agent, the X stripping agent is stripped by the 2B unit, and returns to the 2A unit after OF seasoning, precipitation filtration, and mother liquor destruction, and then extracted by the 2A unit to obtain the aqueous phase W waste liquid, completing a one-time pass without circulation;

[0041] At the same time, 30% TBP-kerosene is independently added as an organic phase X extractant, and the X extractant first passes through the 1A unit to the 1B unit, and then passes through the 1B unit, the 1C unit, the solvent regeneration, the 1A unit and then returns to the 1B unit to realize the organic phase circulation, or passes through the 1B unit, the 1C unit, the solvent regeneration, the 2A unit, the 2B unit and then returns to the 1B unit to realize the organic phase circulation;

[0042] S203: The uranium purification and uranium tail end 2D unit receives the U material from the co-decontamination separation 1C unit or independently adds 0.5 mol / L nitric acid as the aqueous phase F material, and the F material is extracted by the 2D unit to obtain the aqueous phase W waste liquid, completing a one-time pass without circulation;

[0043] 0.01 mol / L nitric acid is added to the 2E unit independently as the aqueous phase X stripping agent, and the X stripping agent is stripped by the 2E unit to obtain the U material, which can be transported to the uranium purification and uranium tail end 3D unit;

[0044] At the same time, 30% TBP-kerosene is added independently as an organic phase X extractant, and the X extractant is sequentially passed through the 2D unit, the 2E unit, and the solvent is regenerated and returned to the 2D unit to realize the organic phase circulation;

[0045] S204: Uranium purification, uranium tail end 3D unit can receive U material from 2E unit or independently add 0.5 mol / L nitric acid as aqueous phase F material, the F material is extracted by 3D unit to obtain aqueous phase W waste liquid, completes one-time pass, and does not circulate;

[0046] 0.01 mol / L nitric acid is independently added to the 3E unit as the aqueous phase X stripping agent. The X stripping agent is stripped by the 3E unit to obtain U material, which can be transported to the sedimentation centrifuge at the head end through the inter-sub-item transport path for reuse;

[0047] At the same time, 30% TBP-kerosene is independently added as an organic phase X extractant, and the X extractant is sequentially passed through the 3D unit, the 3E unit, and the solvent is regenerated and returned to the 3D unit to realize the organic phase circulation;

[0048] S205: When the above steps are carried out, nitric acid passes through each link at one time without circulation, so as to fully replace the waste acid after cleaning;

[0049] S206: The one-time acid pass continues for one week according to the above path. After completion, the waste acid generated by the one-time acid pass will all pass through the emptying system of each sub-item, be neutralized by adding alkali, pass through the nearest floor drain in the green / orange zone, and be transferred through the sump to be discharged as wastewater.

[0050] The S3 specifically includes the following steps:

[0051] S301: The head end receives U material from the uranium purification and 3E units at the tail end of uranium or prepares 0.5 mol / L nitric acid and adds it to the dissolver to obtain acid solution, which is subjected to sedimentation centrifugation, seasoning, and precise metering. The precisely metered acid solution is returned to the acid preparation to realize the head end water phase circulation, or is transported to the 1A unit of co-decontamination separation through the inter-sub-item transport path;

[0052] S302: The 1A unit of the co-decontamination separation, plutonium purification, and plutonium tail receives the acid solution accurately measured from the head end, or independently adds 0.5 mol / L nitric acid as the aqueous phase F material. The F material is extracted by the 1A unit to obtain the aqueous phase W waste liquid, and the "W waste liquid is reused as F material" path is used to realize the internal circulation of the unit;

[0053] 0.5 mol / L nitric acid is independently added to the 1B unit as the aqueous phase X stripping agent, and the X stripping agent is stripped by the 1B unit and then extracted by the 2A unit to obtain the aqueous phase W waste liquid, and the "W waste liquid is reused as F material" path is used to realize the internal circulation of the unit;

[0054] 0.01 mol / L nitric acid is independently added to the 1C unit as the aqueous phase X stripping agent. The X stripping agent is stripped by the 1C unit to obtain the U material, which can be recycled within the unit by using the "W waste liquid as F material reuse" path, or can be transported to the uranium purification and uranium tail end 2D unit by the inter-sub-item transport path;

[0055] Unit 2A can receive the P material obtained after stripping from unit 1B or the material returned from the destruction of the mother liquor or independently add 0.5 mol / L nitric acid as the aqueous phase F material. The F material is extracted by unit 2A to obtain the aqueous phase W waste liquid. The "W waste liquid is reused as F material" path is used to realize the internal circulation of the unit;

[0056] 0.5 mol / L nitric acid is independently added to the 2B unit as the aqueous phase X stripping agent, and the X stripping agent is stripped through the 2B unit, and returns to the 2A unit after OF seasoning, precipitation filtration, and mother liquor destruction, and then extracted through the 2A unit, using the "W waste liquid as F material reuse" path to achieve internal circulation of the unit;

[0057] At the same time, 30% TBP-kerosene is independently added as an organic phase X extractant, and the X extractant first passes through the 1A unit to the 1B unit, and then passes through the 1B unit, the 1C unit, the solvent regeneration, the 1A unit and then returns to the 1B unit to realize the organic phase circulation, or passes through the 1B unit, the 1C unit, the solvent regeneration, the 2A unit, the 2B unit and then returns to the 1B unit to realize the organic phase circulation;

[0058] S303: The 2D unit for uranium purification and uranium tail end can receive the U material from the co-decontamination separation 1C unit or independently add 0.5 mol / L nitric acid as the aqueous phase F material. The F material is extracted by the 2D unit to obtain the aqueous phase W waste liquid. The "W waste liquid is reused as F material" path is used to realize the internal circulation of the unit;

[0059] 0.01 mol / L nitric acid is independently added to the 2E unit as the aqueous phase X stripping agent. The X stripping agent is stripped by the 2E unit to obtain the U material, which can be recycled within the unit by using the "W waste liquid as F material reuse" path, or can be transported to the uranium purification and uranium tail end 3D unit;

[0060] At the same time, 30% TBP-kerosene is added independently as an organic phase X extractant, and the X extractant is sequentially passed through the 2D unit, the 2E unit, and the solvent is regenerated and returned to the 2D unit to realize the organic phase circulation;

[0061] S304: The uranium purification and uranium tail end 3D unit can receive the U material from the 2E unit or independently add 0.5 mol / L nitric acid as the aqueous phase F material. The F material is extracted by the 3D unit to obtain the aqueous phase W waste liquid. The "W waste liquid is reused as F material" path is used to realize the internal circulation of the unit;

[0062] 0.01 mol / L nitric acid is independently added to the 3E unit as the aqueous phase X stripping agent. The X stripping agent is stripped by the 3E unit to obtain the U material, which can be recycled within the unit by using the "W waste liquid as F material reuse" path, or can be transported to the sedimentation centrifuge at the head end by the inter-sub-item transport path for reuse;

[0063] At the same time, 30% TBP-kerosene is independently added as an organic phase X extractant, and the X extractant is sequentially passed through the 3D unit, the 3E unit, and the solvent is regenerated and returned to the 3D unit to realize the organic phase circulation;

[0064] S305: All extraction equipment of "1A unit", "1B unit", "1C unit", "2A unit", "2B unit", "2D unit", "2E unit", "3D unit", "3E unit" and each "solvent regeneration" link, including pulse extraction columns and mixing and settling tanks, select operating conditions for hydraulic tests according to the principle of "first the middle, then the two sides". In the initial stage of debugging, the middle value of the reference range is selected, and the subsequent values ​​gradually deviate to larger and smaller values. During the hydraulic test, the organic phase / aqueous phase outlets of all extraction equipment are sampled to measure the phase entrainment ratio; according to the fluctuation of hydraulic parameters and the size of the phase entrainment ratio, three groups of operating conditions with the smallest fluctuation range and the smallest phase entrainment ratio are selected, which represent the best stability.

[0065] The S4 specifically comprises the following steps:

[0066] S401: After the three waste process systems of high-level waste liquid treatment, medium / low-level waste liquid treatment, and contaminated solvent distillation are ready for receiving, the nitric acid of each unit will no longer be reused according to the internal circulation path of the sub-item, but will be treated in the three waste process system according to the linkage path of the three waste sub-items, so as to realize the linkage between the post-treatment main process and the three waste process-related systems, verify the functional matching and load compatibility of the transmission between the systems, and lay the foundation for the 100% chemical test sub-stage;

[0067] S402: All extraction equipment is hydraulically verified using the three sets of optimal operating conditions selected in the previous stage to confirm data reproducibility;

[0068] S403: Simultaneously meet the traditional chemical test method prerequisites such as waste acid denitrification treatment, plant ventilation and exhaust, and nitrogen oxide tail gas treatment, in preparation for the transition to the 100% chemical test sub-stage;

[0069] S404: All extraction equipment is verified for emptying and stopping operations. The aqueous waste acid passes through the emptying system of each sub-item, is neutralized with alkali, and is discharged through the nearest floor drain in the green / orange area and transferred through the sump to be discharged as wastewater. The distillation of the contaminated solvent is achieved by transferring between the sub-items and each unit.

[0070] The S5 specifically includes the following steps:

[0071] S501: Each unit replaces nitric acid with normal operating acidity in advance;

[0072] S502: Consistent with the previous stage, the nitric acid in each unit is not reused according to the internal circulation path of the sub-item, but is transported to the three waste process system for treatment according to the inter-sub-item transportation path;

[0073] S503: All extraction equipment is hydraulically validated using the three selected optimal operating conditions to confirm data reproducibility;

[0074] S504: Through the continuous linkage test of the whole system, the matching of two-phase transportation within and between systems is re-verified, and various parameters of fluid transportation equipment, extraction equipment, etc. are calibrated to test the reliability, switchability and maintenance accessibility of control systems, instruments, and mechanical equipment;

[0075] S505: Determine acid mass transfer and oil removal efficiency.

[0076] Compared with the prior art, the embodiments of the present invention have the following beneficial effects:

[0077] (1) The chemical debugging method for spent fuel reprocessing process provided by the present invention ensures that chemical experiments are started and completed as planned, accumulates a large amount of debugging data, fully verifies the chemical operation performance and equipment reliability under a shorter debugging cycle and lower debugging cost, obtains appropriate process control parameters, and meets the established debugging acceptance indicators.

[0078] (2) The chemical debugging method for spent fuel reprocessing process provided by the present invention can be widely applied to reprocessing debugging and even similar long-term chemical engineering debugging. As a verified debugging plan, it ensures debugging flexibility. This project has pioneering significance for improving the level of China's reprocessing debugging technology.

[0079] (3) The chemical debugging method for spent fuel post-processing provided by the present invention is universal and applicable to both projects with deep cross-compilation of construction and installation and projects with relatively good on-site conditions. It can reduce the risk of debugging and improve the flexibility of debugging by reducing the concentration of nitric acid and setting up multi-stage circulation on the basis of ensuring the effectiveness of the test and the representativeness of the data, and has the advantages of reducing the difficulty of rectification, saving debugging costs, and deepening personnel training. In other words, when the prerequisites such as waste acid denitration treatment, plant ventilation, and nitrogen oxide tail gas treatment are not available, the method of the present invention can also be used to start the chemical test of the post-processing process, so that the construction and debugging resources can be concentrated on the post-processing process, which plays a role in shortening the debugging cycle. BRIEF DESCRIPTION OF THE DRAWINGS

[0080] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0081] Figure 1 A flow chart of a spent fuel post-processing process chemical debugging method provided by the present invention;

[0082] Figure 2 A chemical debugging method path diagram for a spent fuel post-processing process provided by the present invention. DETAILED DESCRIPTION

[0083] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0084] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0085] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0086] Decompose the traditional chemical test task objectives, redesign the chemical test stage, increase the nitric acid concentration level of each material in the post-processing main process system in stages, and gradually release the debugging risk. The redesigned chemical test stage is divided into a 50% chemical test sub-stage and a 100% chemical test sub-stage. The traditional "system test to linkage test" transition process is integrated into the 50% chemical test sub-stage to achieve the transition under low-risk conditions. The specific technical solutions for each stage are as follows:

[0087] In addition, the rationality analysis of the 50% chemical test sub-stage material replacement principle is as follows:

[0088] (1) Among the various chemical test tasks, the optimal operating conditions and hydraulic tests of the extraction equipment take the longest time. The new method takes this test as the core to ensure the progress of the critical path of the commissioning plan. Replacing the aqueous phase material with nitric acid at a concentration lower than the normal operating concentration reduces the acidity of the system, increases the phase separation time, and places higher requirements on the hydraulic performance of the two-phase countercurrent, mixing, and phase separation, which can more effectively test the control level of the two-phase outlet entrainment of the extraction equipment;

[0089] (2) Although the acidity of the system has decreased, it still has the ability to verify two-phase transport, parameter calibration, instrumentation and control functions, and interface matching. It can calibrate key extraction hydraulic monitoring data such as the two-phase interface and density of the pulse extraction column and the mixing and settling tank;

[0090] (3) Considering that the organic phase needs to be recycled and reused within the system using existing pathways, if kerosene is introduced to carry out the oil removal efficiency test, the TBP content of the 30% TBP-kerosene in the system will continue to decrease and lose the representativeness of the organic phase. Therefore, 30% TBP-kerosene is used instead of kerosene to carry out the hydraulic test of the oil removal tank / oil removal column.

[0091] like Figure 1 and Figure 2 As shown, the present invention provides a spent fuel post-processing process chemical debugging method, comprising the following steps:

[0092] S0: Conducting chemical experiments Sub-stage definition:

[0093] (1) 50% Chemical Testing Sub-Phase

[0094] Taking the nitric acid concentration of 3 mol / L during normal operation of 1AF as a benchmark, the concentration of nitric acid selected as the main material to replace 1AF in this stage shall not exceed 50% of the benchmark, that is, ≤1.5 mol / L.

[0095] 0.01-1.5 mol / L nitric acid with an acidity lower than normal operating temperature is used to replace the aqueous phase material, and 30% TBP-kerosene is used as the organic phase material. Necessary temporary circulation or discharge measures are added to the terminal storage tank of the original process flow. With the main post-processing process systems such as the head end, co-decontamination separation, plutonium purification and plutonium tail end, uranium purification and uranium tail end as the core, the system acid cleaning, one-time acid passage, acid circulation, and linkage test are carried out in the order of acid cleaning, one-time acid passage, acid circulation, and linkage test to achieve the goals of acid cleaning, optimal operating conditions of extraction equipment and hydraulic tests (the core tasks of this stage), parameter calibration, and automatic control instrument function verification. Nitric acid and organic phase are gradually realized from the inner system circulation to the inter-system circulation, and are connected in series with the three waste process systems such as high-level radioactive liquid waste treatment, medium- and low-level radioactive liquid waste treatment, and contaminated solvent treatment.

[0096] (2) 100% chemical testing sub-stage

[0097] The nitric acid concentration of 3 mol / L during normal operation of 1AF is taken as a benchmark, and the nitric acid concentration selected to replace the main material of 1AF in this stage is the same as the benchmark, i.e. 3 mol / L.

[0098] The aqueous phase material is replaced by nitric acid with the same normal operating acidity, and 30% TBP-kerosene or kerosene is used as the organic phase material. The temporary discharge measures added to the storage tank at the end of the original process flow are used, and the original chemical test tasks are continued. Full-process chemical linkage tests are carried out under normal operating acidity. The optimal operating conditions and hydraulic operation of the extraction equipment determined in the 50% chemical test sub-stage are verified, and various instrumentation parameters are calibrated for the second time to measure the acid mass transfer performance and oil removal efficiency.

[0099] S1: System acid cleaning for 50% chemical test sub-stage

[0100] For one week, 1.5 mol / L nitric acid was used as the aqueous phase to soak and clean the system to improve the cleanliness. No organic phase was added in this stage. Nitric acid can simultaneously use the aqueous phase path and the organic phase path to maximize the cleaning range. The specific steps include:

[0101] S101: 1.5 mol / L nitric acid is prepared at the head end and added to the dissolver to obtain acid solution, and the acid solution is subjected to sedimentation centrifugation, seasoning, precise metering and other steps to achieve acid cleaning of the head end, and the precisely metered acid solution is returned to the acid preparation to form an internal circulation path to achieve cyclic cleaning of the head end;

[0102] S102: The 1A unit of co-decontamination separation, plutonium purification, and plutonium tail end can receive the acid solution accurately measured from the head end, or independently add 1.5 mol / L nitric acid, and return to the 1A unit in the order of passing through the 1A unit, 1B unit, 1C unit, and solvent regeneration, or return to the 2A unit in the order of passing through the 1A unit, 1B unit, 2A unit, 2B unit, OF seasoning, precipitation filtration, and mother liquor destruction, so as to realize cyclic cleaning;

[0103] The cyclic cleaning also includes a supplementary cycle, wherein the supplementary cycle includes the return of the 2B unit to the 1B unit and the return of the solvent to the 2A unit;

[0104] The cyclic cleaning also includes a sub-item internal circulation, and the sub-item internal circulation includes the return of 1C unit to 1A unit and the destruction of mother liquor to return to 2A unit;

[0105] The cyclic cleaning, supplementary cycle and sub-item internal cycle together realize co-decontamination separation, plutonium purification and cyclic cleaning of the plutonium tail end;

[0106] It also includes internal unit circulation, wherein the internal unit circulation includes utilizing the "W waste liquid reuse as F material" path of the 1A unit and the 2A unit and the "U material reuse as X stripping agent" path of the 1C unit to perform internal unit circulation;

[0107] S103: The 2D unit for uranium purification and uranium tail end can receive nitric acid from the co-decontamination separation 1C unit, or independently add 1.5 mol / L nitric acid, and return to the 2D unit in the order of passing through the 2D unit, the 2E unit, and the solvent regeneration, so as to achieve cyclic cleaning;

[0108] The cyclic cleaning also includes a sub-item internal cycle, and the sub-item internal cycle includes the return of the 2E unit to the 2D unit;

[0109] In addition, the internal circulation of the unit can be carried out by using the "W waste liquid as F material reuse" path of the "2D unit" and the "U material as X stripping agent reuse" path of the "2E unit";

[0110] S104: The 3D unit for uranium purification and uranium tail can receive nitric acid from the 2E unit, or independently add 1.5 mol / L nitric acid, and return to the 3D unit in the order of passing through the 3D unit, the 3E unit, and the solvent regeneration, to achieve cyclic cleaning;

[0111] The cyclic cleaning also includes a sub-item internal cycle, and the sub-item internal cycle includes the 3E unit returning to the 3D unit;

[0112] It also includes internal circulation within the unit, wherein the internal circulation within the unit includes utilizing the "W waste liquid reuse as F material" path of the 3D unit and the "U material reuse as X stripping agent" path of the 3E unit to perform internal circulation within the unit;

[0113] S105: The acid cleaning cycle continues for one week according to the above route. After completion, all the waste acid after cleaning passes through the emptying system of each sub-item, is neutralized by adding alkali, and is discharged as wastewater through the nearest floor drain in the green / orange zone and transferred through the sump.

[0114] When the above steps are carried out, the nitric acid stays in each link for more than 2 hours to perform sufficient immersion and cleaning to improve cleanliness.

[0115] S2: Conduct a one-time acid pass test for the 50% chemical test sub-stage

[0116] After S1 is completed, 0.5 mol / L nitric acid is used as the X stripping agent for F material, 1B and 2B units, and 0.01 mol / L nitric acid is used as the X stripping agent for 1C, 2E, and 3E units, but the water phase is not circulated, and the system is passed through once to fully replace the waste acid after cleaning, and 30% TBP-kerosene is used as the organic phase (also the X extractant). Different from the water phase, this stage uses the existing path of the organic phase for organic phase circulation. Specifically, the following steps are included:

[0117] S201: Acid is prepared at the head end, 0.5 mol / L nitric acid is added to the head end to obtain acid solution, and the acid solution is subjected to sedimentation centrifugation, seasoning, precise metering and other steps to achieve one-time acid passage;

[0118] S202: The 1A unit of the co-decontamination separation, plutonium purification, and plutonium tail end can receive the acid solution accurately measured from the head end or independently add 0.5 mol / L nitric acid as the aqueous phase F material, and the F material is extracted by the 1A unit to obtain the aqueous phase W waste liquid, completing a one-time pass without circulation;

[0119] 0.5 mol / L nitric acid is added to the 1B unit independently as the aqueous phase X stripping agent, the X stripping agent is stripped by the 1B unit, and then extracted by the 2A unit to obtain the aqueous phase W waste liquid, completing a one-time pass without circulation;

[0120] 0.01 mol / L nitric acid is independently added to the 1C unit as the aqueous phase X stripping agent, and the X stripping agent is stripped by the 1C unit to obtain the U material, which can be transported to the uranium purification and uranium tail end 2D unit through the inter-sub-item transport path;

[0121] Unit 2A can receive the P material obtained after stripping from unit 1B or the material returned from the destruction of the mother liquor or independently add 0.5 mol / L nitric acid as the aqueous phase F material. The F material is extracted by unit 2A to obtain the aqueous phase W waste liquid, completing a one-time pass without circulation;

[0122] 0.5 mol / L nitric acid is added to the 2B unit independently as the aqueous phase X stripping agent, the X stripping agent is stripped by the 2B unit, and returns to the 2A unit after OF seasoning, precipitation filtration, and mother liquor destruction, and then extracted by the 2A unit to obtain the aqueous phase W waste liquid, completing a one-time pass without circulation;

[0123] At the same time, 30% TBP-kerosene is independently added as an organic phase X extractant, and the X extractant first passes through the 1A unit to the 1B unit, and then passes through the 1B unit, the 1C unit, the solvent regeneration, the 1A unit and then returns to the 1B unit to realize the organic phase circulation, or passes through the 1B unit, the 1C unit, the solvent regeneration, the 2A unit, the 2B unit and then returns to the 1B unit to realize the organic phase circulation;

[0124] S203: The uranium purification and uranium tail end 2D unit can receive the U material from the co-decontamination separation 1C unit or independently add 0.5 mol / L nitric acid as the aqueous phase F material, and the F material is extracted by the 2D unit to obtain the aqueous phase W waste liquid, completing a one-time pass without circulation;

[0125] 0.01 mol / L nitric acid is added to the 2E unit independently as the aqueous phase X stripping agent, and the X stripping agent is stripped by the 2E unit to obtain the U material, which can be transported to the uranium purification and uranium tail end 3D unit;

[0126] At the same time, 30% TBP-kerosene is added independently as an organic phase X extractant, and the X extractant is sequentially passed through the 2D unit, the 2E unit, and the solvent is regenerated and returned to the 2D unit to realize the organic phase circulation;

[0127] S204: Uranium purification, uranium tail end 3D unit can receive U material from 2E unit or independently add 0.5 mol / L nitric acid as aqueous phase F material, the F material is extracted by 3D unit to obtain aqueous phase W waste liquid, completes one-time pass, and does not circulate;

[0128] 0.01 mol / L nitric acid is independently added to the 3E unit as the aqueous phase X stripping agent. The X stripping agent is stripped by the 3E unit to obtain U material, which can be transported to the sedimentation centrifuge at the head end through the inter-sub-item transport path for reuse;

[0129] At the same time, 30% TBP-kerosene is independently added as an organic phase X extractant, and the X extractant is sequentially passed through the 3D unit, the 3E unit, and the solvent is regenerated and returned to the 3D unit to realize the organic phase circulation;

[0130] S205: When the above steps are carried out, nitric acid passes through each link at one time without circulation, so as to fully replace the waste acid after cleaning;

[0131] S206: The one-time acid pass continues for one week according to the above path. After completion, the waste acid generated by the one-time acid pass will all pass through the emptying system of each sub-item, be neutralized by adding alkali, pass through the nearest floor drain in the green / orange zone, and be transferred through the sump to be discharged as wastewater.

[0132] S3: Carry out acid cycle test of 50% chemical test sub-stage.

[0133] Two months were used, with 0.5 mol / L nitric acid as the X stripping agent for F material, 1B and 2B units, 0.01 mol / L nitric acid as the X stripping agent for 1C, 2E and 3E units, and 30% TBP-kerosene as the organic phase (also the X extractant). In this stage, the water phase and the organic phase were circulated, and the hydraulic test of each unit extraction equipment was focused on. Because the duration was long, a large amount of nitric acid could be saved. Specifically, the following steps were included:

[0134] S301: The head end can receive U material from the uranium purification and 3E units at the tail end of uranium or prepare 0.5 mol / L nitric acid and add it to the dissolver to obtain acid solution. The acid solution undergoes sedimentation centrifugation, seasoning, and precise metering. The precisely metered acid solution can be returned to the acid preparation to achieve the head end water phase circulation, or it can be transported to the 1A unit of co-decontamination separation through the inter-sub-item transport path;

[0135] S302: The 1A unit for co-decontamination separation, plutonium purification, and plutonium tail end can receive the acid solution accurately measured from the head end, or independently add 0.5 mol / L nitric acid as the aqueous phase F material. The F material is extracted by the 1A unit to obtain the aqueous phase W waste liquid, and the "W waste liquid is reused as F material" path is used to realize the internal circulation of the unit;

[0136] 0.5 mol / L nitric acid is independently added to the 1B unit as the aqueous phase X stripping agent, and the X stripping agent is stripped by the 1B unit and then extracted by the 2A unit to obtain the aqueous phase W waste liquid, and the "W waste liquid is reused as F material" path is used to realize the internal circulation of the unit;

[0137] 0.01 mol / L nitric acid is independently added to the 1C unit as the aqueous phase X stripping agent. The X stripping agent is stripped by the 1C unit to obtain the U material, which can be recycled within the unit by using the "W waste liquid as F material reuse" path, or can be transported to the uranium purification and uranium tail end 2D unit by the inter-sub-item transport path;

[0138] Unit 2A can receive the P material obtained after stripping from unit 1B or the material returned from the destruction of the mother liquor or independently add 0.5 mol / L nitric acid as the aqueous phase F material. The F material is extracted by unit 2A to obtain the aqueous phase W waste liquid. The "W waste liquid is reused as F material" path is used to realize the internal circulation of the unit;

[0139] 0.5 mol / L nitric acid is independently added to the 2B unit as the aqueous phase X stripping agent, and the X stripping agent is stripped through the 2B unit, and returns to the 2A unit after OF seasoning, precipitation filtration, and mother liquor destruction, and then extracted through the 2A unit, using the "W waste liquid as F material reuse" path to achieve internal circulation of the unit;

[0140] At the same time, 30% TBP-kerosene is independently added as an organic phase X extractant, and the X extractant first passes through the 1A unit to the 1B unit, and then passes through the 1B unit, the 1C unit, the solvent regeneration, the 1A unit and then returns to the 1B unit to realize the organic phase circulation, or passes through the 1B unit, the 1C unit, the solvent regeneration, the 2A unit, the 2B unit and then returns to the 1B unit to realize the organic phase circulation;

[0141] S303: The 2D unit for uranium purification and uranium tail end can receive the U material from the co-decontamination separation 1C unit or independently add 0.5 mol / L nitric acid as the aqueous phase F material. The F material is extracted by the 2D unit to obtain the aqueous phase W waste liquid. The "W waste liquid is reused as F material" path is used to realize the internal circulation of the unit;

[0142] 0.01 mol / L nitric acid is independently added to the 2E unit as the aqueous phase X stripping agent. The X stripping agent is stripped by the 2E unit to obtain the U material, which can be recycled within the unit by using the "W waste liquid as F material reuse" path, or can be transported to the uranium purification and uranium tail end 3D unit;

[0143] At the same time, 30% TBP-kerosene is added independently as an organic phase X extractant, and the X extractant is sequentially passed through the 2D unit, the 2E unit, and the solvent is regenerated and returned to the 2D unit to realize the organic phase circulation;

[0144] S304: The uranium purification and uranium tail end 3D unit can receive the U material from the 2E unit or independently add 0.5 mol / L nitric acid as the aqueous phase F material. The F material is extracted by the 3D unit to obtain the aqueous phase W waste liquid. The "W waste liquid is reused as F material" path is used to realize the internal circulation of the unit;

[0145] 0.01 mol / L nitric acid is independently added to the 3E unit as the aqueous phase X stripping agent. The X stripping agent is stripped by the 3E unit to obtain the U material, which can be recycled within the unit by using the "W waste liquid as F material reuse" path, or can be transported to the sedimentation centrifuge at the head end by the inter-sub-item transport path for reuse;

[0146] At the same time, 30% TBP-kerosene is independently added as an organic phase X extractant, and the X extractant is sequentially passed through the 3D unit, the 3E unit, and the solvent is regenerated and returned to the 3D unit to realize the organic phase circulation;

[0147] S305: All extraction equipment of "1A unit", "1B unit", "1C unit", "2A unit", "2B unit", "2D unit", "2E unit", "3D unit", "3E unit", and "solvent regeneration" links, including pulse extraction columns and mixing and settling tanks, select operating conditions for hydraulic tests according to the principle of "first the middle, then the two sides". In the initial debugging, the middle value of the reference range is selected, and the subsequent values ​​gradually deviate to larger and smaller values. During the hydraulic test, the organic phase / water phase outlets of all extraction equipment are sampled to measure the phase entrainment ratio (i.e., the volume fraction of organic phase entrained in the water phase or the volume fraction of water phase entrained in the organic phase). According to the fluctuation of hydraulic parameters and the size of the phase entrainment ratio, three groups of operating conditions with the smallest fluctuation range and the smallest phase entrainment ratio are selected, which represent the best stability.

[0148] S4: Conduct linkage tests for the 50% chemical test sub-phase

[0149] Over a period of one week, 0.5 mol / L nitric acid was added as the aqueous phase and 30% TBP-kerosene was added as the organic phase. During this stage, the organic phase was circulated, but the aqueous phase was not circulated, and the focus was on the linkage verification of the transport paths between the sub-items. Specifically, the following steps were included:

[0150] S401: After the three waste process systems such as high-level waste liquid treatment, medium / low-level waste liquid treatment, and contaminated solvent distillation are ready for receiving, the nitric acid of each unit will no longer be reused according to the internal circulation path of the sub-item, but will be treated in the three waste process system according to the linkage path of the three waste sub-items, so as to realize the linkage between the post-treatment main process and the three waste process-related systems, verify the functional matching and load compatibility of the transmission between the systems, and lay the foundation for the 100% chemical test sub-stage;

[0151] S402: All extraction equipment is hydraulically verified using the three sets of optimal operating conditions selected in the previous stage to confirm data reproducibility;

[0152] S403: Simultaneously meet the traditional chemical test method prerequisites such as waste acid denitrification treatment, plant ventilation and exhaust, and nitrogen oxide tail gas treatment, in preparation for the transition to the 100% chemical test sub-stage;

[0153] S404: All extraction equipment is verified for emptying and stopping operations. The aqueous waste acid passes through the emptying system of each sub-item, is neutralized with alkali, and is discharged through the nearest floor drain in the green / orange area and transferred through the sump to be discharged as wastewater. The distillation of the contaminated solvent is achieved by transferring between the sub-items and each unit.

[0154] S5: Conduct linkage test of 100% chemical test sub-stage

[0155] In one week, add normal operating acidity (up to 11 mol / L) as the water phase and add 30% TBP-kerosene as the organic phase. During this stage, the organic phase circulates and the water phase does not circulate. The focus is on verifying the normal operating acidity conditions of the selected operating conditions. Specifically, the following steps are included:

[0156] S501: Each unit replaces nitric acid with normal operating acidity in advance;

[0157] S502: Consistent with the previous stage, the nitric acid in each unit is not reused according to the internal circulation path of the sub-item, but is transported to the three waste process system for treatment according to the inter-sub-item transportation path;

[0158] S503: All extraction equipment is hydraulically validated using the three selected optimal operating conditions to confirm data reproducibility;

[0159] S504: Through the continuous linkage test of the whole system, the matching of two-phase transportation within and between systems is re-verified, and various parameters of fluid transportation equipment, extraction equipment, etc. are calibrated to test the reliability, switchability and maintenance accessibility of control systems, instruments, and mechanical equipment;

[0160] S505: Determine acid mass transfer and oil removal efficiency.

[0161] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

[0162] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A spent fuel post-processing process chemical debugging method, characterized in that: The steps include: S0: Perform the chemical test sub-stage, which is defined as the 50% chemical test sub-stage and the 100% chemical test sub-stage; S1: System acid cleaning for 50% chemical test sub-stage For one week, the system was soaked and cleaned with 1.5 mol / L nitric acid as the aqueous phase to improve cleanliness. No organic phase was added in this stage. Nitric acid can simultaneously use the aqueous phase path and the organic phase path to maximize the cleaning range. S2: Conduct a one-time acid pass test for the 50% chemical test sub-stage After S1 is completed, 0.5 mol / L nitric acid is used as the X stripping agent for F material, 1B and 2B units, and 0.01 mol / L nitric acid is used as the X stripping agent for 1C, 2E, and 3E units, but the water phase is not circulated. The system is passed through once to fully replace the waste acid after washing. 30% TBP-kerosene is used as the organic phase, that is, the X extractant. Unlike the water phase, the existing path of the organic phase is used for organic phase circulation in this stage; S3: Conduct acid cycle test for 50% chemical test sub-stage In two months, 0.5 mol / L nitric acid was used as the X stripping agent for F material, 1B and 2B units, 0.01 mol / L nitric acid was used as the X stripping agent for 1C, 2E and 3E units, and 30% TBP-kerosene was used as the organic phase, i.e., the X extractant. During this stage, the water phase circulation and the organic phase circulation were carried out, and the hydraulic test of each unit extraction equipment was focused on; S4: Conduct linkage tests for the 50% chemical test sub-phase Over a period of one week, 0.5 mol / L nitric acid was added as the aqueous phase and 30% TBP-kerosene was added as the organic phase. During this stage, the organic phase was circulated but the aqueous phase was not circulated, and the linkage verification of the transport paths between the sub-items was focused. S5: Conduct linkage test of 100% chemical test sub-stage Over a period of one week, normal operating acidity (up to 11 mol / L) was added as the aqueous phase, and 30% TBP-kerosene was added as the organic phase. During this stage, the organic phase was circulated and the aqueous phase was not circulated. The focus was on verifying the normal operating acidity conditions for the selected operating conditions.

2. The spent fuel reprocessing process chemical debugging method according to claim 1, characterized in that: The S1 specifically includes the following steps: S101: 1.5 mol / L nitric acid is prepared at the head end and added to the dissolver to obtain acid solution, and the acid solution is subjected to sedimentation centrifugation, seasoning, and precise metering to achieve acid cleaning of the head end, and the precisely metered acid solution returns to the acid preparation to form an internal circulation path to achieve cyclic cleaning of the head end; S102: The 1A unit of co-decontamination separation, plutonium purification, and plutonium tail end can receive the acid solution accurately measured from the head end, or independently add 1.5 mol / L nitric acid, and return to the 1A unit in the order of passing through the 1A unit, 1B unit, 1C unit, and solvent regeneration, or return to the 2A unit in the order of passing through the 1A unit, 1B unit, 2A unit, 2B unit, OF seasoning, precipitation filtration, and mother liquor destruction, so as to realize cyclic cleaning; Also includes a supplementary cycle, the supplementary cycle includes the return of the 2B unit to the 1B unit and the return of the solvent to the 2A unit; It also includes a sub-item internal cycle, wherein the sub-item internal cycle includes the return of unit 1C to unit 1A and the destruction of mother liquor to unit 2A; The cyclic cleaning, supplementary cycle and sub-item internal cycle together realize co-decontamination separation, plutonium purification and cyclic cleaning of the plutonium tail end; S103: The 2D unit for uranium purification and uranium tail end can receive nitric acid from the co-decontamination separation 1C unit, or independently add 1.5 mol / L nitric acid, and return to the 2D unit in the order of passing through the 2D unit, the 2E unit, and the solvent regeneration, so as to achieve cyclic cleaning; Also includes a sub-item inner loop, the sub-item inner loop includes the 2E unit returning the 2D unit; S104: The 3D unit for uranium purification and uranium tail can receive nitric acid from the 2E unit, or independently add 1.5 mol / L nitric acid, and return to the 3D unit in the order of passing through the 3D unit, the 3E unit, and the solvent regeneration, to achieve cyclic cleaning; Also included is a sub-item inner loop, the sub-item inner loop including the 3E unit returning to the 3D unit; S105: The acid cleaning cycle continues for one week according to the above path. After completion, all the waste acid after cleaning passes through the emptying system of each sub-item, is neutralized by adding alkali, and is discharged as wastewater through the nearest floor drain in the green / orange zone and the sump; When the above steps are carried out, the nitric acid stays in each link for more than 2 hours to perform sufficient immersion and cleaning to improve cleanliness.

3. The spent fuel post-processing process chemical debugging method according to claim 2, characterized in that: The S102 also includes internal unit circulation, which includes utilizing the "W waste liquid as F material reuse" path of the 1A unit and the 2A unit and the "U material as X stripping agent reuse" path of the 1C unit to perform internal unit circulation.

4. The spent fuel post-processing process chemical debugging method according to claim 2, characterized in that: The S102 also includes internal unit circulation, which utilizes the "W waste liquid reuse as F material" path of the 2D unit and the "U material reuse as X stripping agent" path of the "2E unit" to perform internal unit circulation.

5. The spent fuel reprocessing process chemical debugging method according to claim 2, characterized in that: The S102 also includes internal unit circulation, which includes utilizing the "W waste liquid reuse as F material" path of the 3D unit and the "U material reuse as X stripping agent" path of the 3E unit to perform internal unit circulation.

6. The spent fuel post-processing process chemical debugging method according to claim 2, characterized in that: The S2 specifically includes the following steps: S201: Acid is prepared at the head end, 0.5 mol / L nitric acid is added to the head end to obtain acid solution, and the acid solution is subjected to sedimentation centrifugation, seasoning, precise metering and other steps to achieve one-time acid passage; S202: The 1A unit of the co-decontamination separation, plutonium purification, and plutonium tail end can receive the acid solution accurately measured from the head end or independently add 0.5 mol / L nitric acid as the aqueous phase F material, and the F material is extracted by the 1A unit to obtain the aqueous phase W waste liquid, completing a one-time pass without circulation; 0.5 mol / L nitric acid is added to the 1B unit independently as the aqueous phase X stripping agent, the X stripping agent is stripped by the 1B unit, and then extracted by the 2A unit to obtain the aqueous phase W waste liquid, completing a one-time pass without circulation; 0.01 mol / L nitric acid is independently added to the 1C unit as the aqueous phase X stripping agent, and the X stripping agent is stripped by the 1C unit to obtain the U material, which can be transported to the uranium purification and uranium tail end 2D unit through the inter-sub-item transport path; Unit 2A can receive the P material obtained after stripping from unit 1B or the material returned from the destruction of the mother liquor or independently add 0.5 mol / L nitric acid as the aqueous phase F material. The F material is extracted by unit 2A to obtain the aqueous phase W waste liquid, completing a one-time pass without circulation; 0.5 mol / L nitric acid is added to the 2B unit independently as the aqueous phase X stripping agent, the X stripping agent is stripped by the 2B unit, and returns to the 2A unit after OF seasoning, precipitation filtration, and mother liquor destruction, and then extracted by the 2A unit to obtain the aqueous phase W waste liquid, completing a one-time pass without circulation; At the same time, 30% TBP-kerosene is independently added as an organic phase X extractant, and the X extractant first passes through the 1A unit to the 1B unit, and then passes through the 1B unit, the 1C unit, the solvent regeneration, the 1A unit and then returns to the 1B unit to realize the organic phase circulation, or passes through the 1B unit, the 1C unit, the solvent regeneration, the 2A unit, the 2B unit and then returns to the 1B unit to realize the organic phase circulation; S203: The uranium purification and uranium tail end 2D unit receives the U material from the co-decontamination separation 1C unit or independently adds 0.5 mol / L nitric acid as the aqueous phase F material, and the F material is extracted by the 2D unit to obtain the aqueous phase W waste liquid, completing a one-time pass without circulation; 0.01 mol / L nitric acid is added to the 2E unit independently as the aqueous phase X stripping agent, and the X stripping agent is stripped by the 2E unit to obtain the U material, which can be transported to the uranium purification and uranium tail end 3D unit; At the same time, 30% TBP-kerosene is added independently as an organic phase X extractant, and the X extractant is sequentially passed through the 2D unit, the 2E unit, and the solvent is regenerated and returned to the 2D unit to realize the organic phase circulation; S204: Uranium purification, uranium tail end 3D unit can receive U material from 2E unit or independently add 0.5 mol / L nitric acid as aqueous phase F material, the F material is extracted by 3D unit to obtain aqueous phase W waste liquid, completes one-time pass, and does not circulate; 0.01 mol / L nitric acid is independently added to the 3E unit as the aqueous phase X stripping agent. The X stripping agent is stripped by the 3E unit to obtain U material, which can be transported to the sedimentation centrifuge at the head end through the inter-sub-item transport path for reuse; At the same time, 30% TBP-kerosene is independently added as an organic phase X extractant, and the X extractant is sequentially passed through the 3D unit, the 3E unit, and the solvent is regenerated and returned to the 3D unit to realize the organic phase circulation; S205: When the above steps are carried out, nitric acid passes through each link at one time without circulation, so as to fully replace the waste acid after cleaning; S206: The one-time acid pass continues for one week according to the above path. After completion, the waste acid generated by the one-time acid pass will all pass through the emptying system of each sub-item, be neutralized by adding alkali, pass through the nearest floor drain in the green / orange zone, and be transferred through the sump to be discharged as wastewater.

7. The spent fuel post-processing process chemical debugging method according to claim 6, characterized in that: The S3 specifically includes the following steps: S301: The head end receives U material from the uranium purification and 3E units at the tail end of uranium or prepares 0.5 mol / L nitric acid and adds it to the dissolver to obtain acid solution, which is subjected to sedimentation centrifugation, seasoning, and precise metering. The precisely metered acid solution is returned to the acid preparation to realize the head end water phase circulation, or is transported to the 1A unit of co-decontamination separation through the inter-sub-item transport path; S302: The 1A unit of co-decontamination separation, plutonium purification, and plutonium tail receives the acid solution accurately measured from the head end, or independently adds 0.5 mol / L nitric acid as the aqueous phase F material. The F material is extracted by the 1A unit to obtain the aqueous phase W waste liquid, and the "W waste liquid is reused as F material" path is used to realize the internal circulation of the unit; 0.5 mol / L nitric acid is independently added to the 1B unit as the aqueous phase X stripping agent, the X stripping agent is stripped by the 1B unit, and then extracted by the 2A unit to obtain the aqueous phase W waste liquid, and the "W waste liquid is reused as F material" path is used to realize the internal circulation of the unit; 0.01 mol / L nitric acid is independently added to the 1C unit as the aqueous phase X stripping agent. The X stripping agent is stripped by the 1C unit to obtain the U material, which can be recycled within the unit by using the "W waste liquid as F material reuse" path, or can be transported to the uranium purification and uranium tail end 2D unit through the inter-sub-item transport path; Unit 2A can receive the P material obtained after stripping from unit 1B or the material returned from the destruction of the mother liquor or independently add 0.5 mol / L nitric acid as the aqueous phase F material. The F material is extracted by unit 2A to obtain the aqueous phase W waste liquid. The "W waste liquid is reused as F material" path is used to realize the internal circulation of the unit; 0.5 mol / L nitric acid is added to the 2B unit independently as the aqueous phase X stripping agent, the X stripping agent is stripped through the 2B unit, and returns to the 2A unit after OF seasoning, precipitation filtration, and mother liquor destruction, and then extracted through the 2A unit, using the "W waste liquid as F material reuse" path to achieve internal circulation of the unit; At the same time, 30% TBP-kerosene is independently added as an organic phase X extractant, and the X extractant first passes through the 1A unit to the 1B unit, and then passes through the 1B unit, the 1C unit, the solvent regeneration, the 1A unit and then returns to the 1B unit to realize the organic phase circulation, or passes through the 1B unit, the 1C unit, the solvent regeneration, the 2A unit, the 2B unit and then returns to the 1B unit to realize the organic phase circulation; S303: The uranium purification and uranium tail end 2D unit can receive the U material from the co-decontamination separation 1C unit or independently add 0.5 mol / L nitric acid as the aqueous phase F material. The F material is extracted by the 2D unit to obtain the aqueous phase W waste liquid. The "W waste liquid is reused as F material" path is used to realize the internal circulation of the unit; 0.01 mol / L nitric acid is independently added to the 2E unit as the aqueous phase X stripping agent. The X stripping agent is stripped by the 2E unit to obtain the U material, which can be recycled within the unit by using the "W waste liquid as F material reuse" path, or can be transported to the uranium purification and uranium tail end 3D unit; At the same time, 30% TBP-kerosene is added independently as an organic phase X extractant, and the X extractant is sequentially passed through the 2D unit, the 2E unit, and the solvent is regenerated and returned to the 2D unit to realize the organic phase circulation; S304: The uranium purification and uranium tail end 3D unit can receive the U material from the 2E unit or independently add 0.5 mol / L nitric acid as the aqueous phase F material. The F material is extracted by the 3D unit to obtain the aqueous phase W waste liquid. The "W waste liquid is reused as F material" path is used to realize the internal circulation of the unit; 0.01 mol / L nitric acid is independently added to the 3E unit as the aqueous phase X stripping agent. The X stripping agent is stripped by the 3E unit to obtain U material, which can be recycled within the unit by using the "W waste liquid as F material reuse" path, or can be transported to the sedimentation centrifuge at the head end by the inter-sub-item transport path for reuse; At the same time, 30% TBP-kerosene is independently added as an organic phase X extractant, and the X extractant is sequentially passed through the 3D unit, the 3E unit, and the solvent is regenerated and returned to the 3D unit to realize the organic phase circulation; S305: "1A unit", "1B unit", "1C unit", "2A unit", "2B unit", "2D unit", "2E unit", "3D unit", "3E unit", and all extraction equipment in various "solvent regeneration" links, including pulse extraction columns and mixing and settling tanks. The operating conditions are selected according to the principle of "middle first, then both sides" for hydraulic tests. The middle value of the reference range is selected in the initial debugging stage, and the subsequent values ​​gradually deviate to larger and smaller values. During the hydraulic test, the organic phase / aqueous phase outlets of all extraction equipment are sampled to measure the phase entrainment ratio; according to the fluctuation of hydraulic parameters and the size of the phase entrainment ratio, three groups of operating conditions with the smallest fluctuation range and the smallest phase entrainment ratio are selected, which represent the best stability.

8. The spent fuel post-processing process chemical debugging method according to claim 7, characterized in that: The S4 specifically comprises the following steps: S401: After the three waste process systems of high-level waste liquid treatment, medium / low-level waste liquid treatment, and contaminated solvent distillation are ready for receiving, the nitric acid of each unit will no longer be reused according to the internal circulation path of the sub-item, but will be treated in the three waste process system according to the linkage path of the three waste sub-items, so as to realize the linkage between the post-treatment main process and the three waste process-related systems, verify the functional matching and load compatibility of the transmission between the systems, and lay the foundation for the 100% chemical test sub-stage; S402: All extraction equipment is hydraulically verified using the three sets of optimal operating conditions selected in the previous stage to confirm data reproducibility; S403: Simultaneously meet the traditional chemical test method prerequisites such as waste acid denitrification treatment, plant ventilation and exhaust, and nitrogen oxide tail gas treatment, in preparation for the transition to the 100% chemical test sub-stage; S404: All extraction equipment is verified for emptying and stopping operations. The aqueous waste acid passes through the emptying system of each sub-item, is neutralized with alkali, and is discharged through the nearest floor drain in the green / orange area and transferred through the sump to be discharged as wastewater. The distillation of the contaminated solvent is achieved by transferring between the sub-items and each unit.

9. The spent fuel post-processing process chemical debugging method according to claim 8, characterized in that: The S5 specifically includes the following steps: S501: Each unit replaces nitric acid with normal operating acidity in advance; S502: Consistent with the previous stage, the nitric acid in each unit is not reused according to the internal circulation path of the sub-item, but is transported to the three waste process system for treatment according to the inter-sub-item transportation path; S503: All extraction equipment is hydraulically validated using the three selected optimal operating conditions to confirm data reproducibility; S504: Through the continuous linkage test of the whole system, the matching of two-phase transportation within and between systems is re-verified, and various parameters of fluid transportation equipment, extraction equipment, etc. are calibrated to test the reliability, switchability and maintenance accessibility of control systems, instruments, and mechanical equipment; S505: Determine acid mass transfer and oil removal efficiency.

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