4 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.

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 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.