9 results about "PUREX" patented technology

The invention discloses a method for extracting technetium from PUREX process waste liquid. The method comprises the working procedures of material blending, extraction, washing, reduction reverse extraction and reverse extraction. According to the technetium extraction and purification process, the technetium is separated from elements such as zirconium, niobium, ruthenium, uranium, neptunium and plutonium by using the technetium as a raw material, tributyl phosphate (TBP) as an extracting agent and hydrogenated kerosene (OK) as a diluent, meanwhile, the economy and safety of the reagents adopted by the process are verified by engineering, and the operation process of each procedure also meets the requirements of high flux, continuous treatment and remote operation.

The application discloses a method for reducing the content of plutonium and neptunium in a uranium product solution in a spent fuel reprocessing PUREX process, which comprises the following steps: adjusting the 2DF material liquid, washing the extraction organic phase by using a washing agent with complexing and reducing double effects in an extraction device, and reducing the content of neptunium and plutonium in the uranium-containing organic phase, so as to obtain a uranium product solution with greatly reduced content of plutonium and neptunium through back extraction. 2 The method has the advantages of simple process, and the decontamination factor of plutonium and neptunium is 10 4 orders of magnitude after 2D tank extraction and washing, and the content of plutonium and neptunium in the uranium product solution is greatly reduced after only one extraction cycle of the uranium line, so that the requirements for the operation control precision and the solvent quality of the process are reduced, the probability of unqualified uranium product solution due to the excessive content of plutonium and neptunium is greatly reduced, the quality of the uranium product is improved, the method has a remarkable removal effect on the fission products such as zirconium, niobium and ruthenium in the uranium product, and can be effectively applied to the PUREX process.

This invention relates to a method for extracting technetium from nuclear fuel reprocessing waste using an extraction method, comprising the following steps: preparing a technetium-zirconium co-extraction feed; co-extracting technetium and zirconium using a TBP-kerosene organic solution as the extractant; reducing and back-extracting the technetium in the TBP organic phase co-extraction solution using a reducing stripping agent; and back-extracting the zirconium in the remaining TBP organic phase using a complexing stripping agent. This method improves upon existing techniques for extracting technetium from nuclear fuel reprocessing waste using extraction methods, which generate a significant amount of organic phase radioactive waste other than tributyl phosphate and require an additional solvent treatment system. It avoids introducing additional solvents and metal ion groups into the reprocessing system and is better compatible with the main process flow and facilities of reprocessing plants using the PUREX process, thus making the technetium extraction process easier to implement in reprocessing plants. The method provided by this invention prevents technetium from entering vitrification and geological disposal, thus preventing long-term hazards to the biosphere.

The invention relates to a device and a method for catalytic decomposition of a reducing agent in a PUREX process raffinate, the device comprises a storage tank, the storage tank collects the raffinate generated by a front-end process, the storage tank is connected with a constant liquid level preposed tank through a pipeline, the constant liquid level preposed tank is connected with a gas-liquid separation tank A through a pipeline, the gas-liquid separation tank A is connected with a preheating device through a pipeline, the preheating device is connected with a catalytic reaction device, and the catalytic reaction device is connected with a gas-liquid separation tank B through a pipeline. The catalytic reaction equipment is respectively connected with the gas-liquid separation tank B and the waste liquid receiving equipment, and the gas-liquid separation tank B is also connected with the tail gas treatment system. According to the invention, nitrogen oxide preparation and conveying systems are reduced; the whole process is convenient to operate, unattended operation can be realized only by controlling the flow and temperature of the feed liquid, and the irradiation dose of personnel is reduced; and the generated tail gas is less and is only nitrogen oxide generated by decomposition of a reducing agent, so that the burden of tail gas treatment in a factory can be reduced.

The present invention relates to a method for removing plutonium and neptunium from uranium in the PUREX thin process, which comprises the following steps: (1) Feed liquid pretreatment: Receiving the uranium-containing aqueous solution 1CU from the co-decontamination separation cycle, and obtaining the 2DF solution after sequential acid adjustment, heating, valence adjustment and acid adjustment treatments; (2) Extraction and washing: Using the detergent 2DS and the extractant 2DX to perform extraction and washing on the 2DF solution to obtain the organic phase 2DU' and the aqueous phase 2DW; (3) Reduction stripping: Using the reduction stripping agent 2DNS to perform reduction stripping on the organic phase 2DU' to obtain the organic phase 2DU and the aqueous phase 2DNW; (4) Stripping: Using the stripping agent 2EX to perform stripping on the organic phase 2DU to obtain the product liquid 2EU and the aqueous phase 2EW. Compared with the prior art, the present invention provides a technical route for uranium purification in a thin process, achieving the goal of removing plutonium and neptunium simultaneously in one uranium purification cycle and obtaining a qualified uranium product.

The application discloses an evaporator and a PUREX process system, which comprises a heating chamber and a separation chamber, the heating chamber is an annular gap heating chamber, a feed liquid inlet and a concentrated liquid outlet are arranged on the annular gap heating chamber, a heating piece is arranged outside the heating chamber, and a hollow part is filled with a neutron poison; the bottom of the separation chamber is communicated with the top of the heating chamber, the top of the separation chamber is provided with a secondary steam outlet, and a leaching liquid inlet is further arranged on the separation chamber. The evaporator has the advantages of simple structure, large capacity, long discharge interval, low operation frequency, high purification efficiency, satisfaction of critical safety, very stable operation, realization of evaporation and concentration of plutonium-containing liquid, recovery of plutonium in a reprocessing plant and reduction of plutonium loss.

The invention relates to the technical field of uranium and plutonium separation, and provides a treatment method in a PUREX process, the treatment method comprises the following steps: adding a reducing agent, a characteristic complexing agent and a feed liquid containing uranium, plutonium and technetium into a plutonium back extractor, the plutonium in the feed liquid is reduced by the reducing agent, and technetium in the feed liquid and the characteristic complexing agent generate a liquid complex so as to jointly generate a plutonium-containing aqueous phase back extraction liquid; the feed liquid subjected to reduction back extraction generates uranium-containing organic phase back extraction liquid. Tc (V) and Tc (IV) are selectively complexed by the characteristic complexing agent, and the catalytic action of technetium can be inhibited or even blocked, so that technetium catalytic cycle failure is promoted, excessive use of a reducing agent can be avoided to a certain extent, the effective separation effect of uranium and plutonium is improved, the influence of technetium on the valence state of neptunium can be avoided to a certain extent, and the catalytic action of technetium can be inhibited or even blocked; the method is of great significance in controlling neptunium and technetium trend, improving uranium and plutonium product quality and reducing radionuclide harm.

This invention belongs to the field of spent fuel reprocessing technology, specifically relating to a spent fuel reprocessing method based on uranium clusters, comprising the following steps: S1, disassembling the spent fuel assembly and cutting it into small fuel rods; S2, dissolving the spent fuel using hydrogen peroxide and an alkaline solution, filtering to obtain a precipitate and filtrate; S3, treating the filtrate obtained in S2 using gel electrophoresis to separate uranium clusters and a solution containing Pu, actinides, and fission products; S4, adding dilute nitric acid and hydrogen peroxide to the uranium clusters obtained in S3 to convert uranium peroxide clusters into uranium filament precipitate, filtering to obtain the precipitate, thus achieving the separation of uranium elements. This invention's spent fuel reprocessing process based on uranium clusters is a spent fuel reprocessing process with advantages such as simple procedures, low corrosiveness, no risk of nuclear proliferation, and better economic benefits compared to the PUREX process.

Title: A Process for Treating Plutonium Retained in the Waste Organic Phase of the PUREX Process The present invention relates to a process for treating plutonium retained in a waste organic phase of a PUREX process. The waste organic phase of the PUREX process comprises an organic solvent and plutonium, the process comprises: contacting the waste organic phase of the PUREX process with an aqueous phase re-extraction solution containing 2,6-pyridinedicarboxylic acid to perform re-extraction, to obtain a plutonium re-extraction product; the plutonium in the re-extraction solution may be loaded onto a column for adsorption, transformation and desorption by an anion exchange column to recover the plutonium in the re-extraction solution.The method can effectively elute and recover plutonium in the waste organic phase, especially can effectively elute plutonium in the waste organic phase which has been stored for a long time. Figure for abstract: Fig.1.