摘要:
L'invention se rapporte à un procédé pour désextraire de l'U(VI) et un actinide(IV) d'une solution organique dans laquelle l'U(VI) et l'actinide(IV) sont présents sous la forme de nitrates à des concentrations telles que la concentration du nitrate d'U(VI) est supérieure à la concentration du nitrate d'actinide(IV), et la somme des concentrations des nitrates d'U(VI) et d'actinide(IV) est ≥ 55 g/L, la solution organique comprenant du TBP dans un diluant organique, lequel procédé comprend : - au moins une mise en contact de la solution organique avec une solution aqueuse comprenant de 2 mol/L à 6 mol/L d'acide nitrique et de l'acide oxalique à une concentration ≥ 18 g/L dans un rapport volumique O/A ≥ 1, la concentration de l'acide oxalique et le rapport volumique O/A étant choisis de sorte que l'acide oxalique soit en défaut par rapport aux conditions stoechiométriques d'une précipitation complète de l'U(VI) et de l'actinide(IV), moyennant quoi on obtient un précipité qui comprend l'actinide(IV) sous forme d'oxalate et de l'U(VI) sous forme d'oxalate dans un rapport massique U(VI)/actinide(IV) compris entre 0,5 et 5 ; puis - une séparation du précipité des solutions organique et aqueuse. Elle se rapporte également à un procédé de traitement d'une solution aqueuse issue de la dissolution d'un combustible nucléaire usé dans de l'acide nitrique, dans lequel est mis en oeuvre ce procédé de désextraction.
摘要:
A method of making a nuclear fuel structure may include reducing a metal oxide in a cathode assembly so as to deposit a metal of the metal oxide on the cathode plate of the cathode assembly, and processing the cathode plate with the metal deposited thereon to fabricate the nuclear fuel structure. The cathode plate may include an upper blade including an electrically conductive material, a lower blade portion connected to the upper blade, and a connection structure configured to secure the lower blade portion to the upper blade while providing electrical continuity. The connection structure may be configured to be disconnected from the lower blade portion to detach the lower blade portion from the upper blade.
摘要:
A method 220 for stabilizing a nuclear material may include electrolytically reducing 220d the nuclear material in a first molten salt electrolyte of an electroreducer to produce a reduced material. A reducer waste may accumulate in the first molten salt electrolyte as a byproduct of the electroreduction. After the electroreduction, the reduced material may be electrolytically dissolved 230b in a second molten salt electrolyte of an electrorefiner to produce a purified metal product on a refiner cathode assembly of the electrorefiner. As a result of the electrorefining, a first refiner waste may accumulate in the second molten salt electrolyte and a second refiner waste may accumulate in a refiner anode assembly of the electrorefiner. The reducer waste from the electroreducer and the first refiner waste from the electrorefiner may be converted into a ceramic waste form, while the second refiner waste from the electrorefiner may be converted into a metallic waste form.
摘要:
A method to analyze crystals in a deposit on a surface of a nuclear generating station heating surface, wherein the method extracts a sample of material from the surface of the nuclear generating station heating surface and also includes conducting at least one of a high resolution scanning electron microscope/energy dispersive X-ray spectrometry of the sample and a scanning transmission electron microscope/selected area electron diffraction/spot and elemental mapping analysis of the sample.
摘要:
A passive assembly for operating a cleaning chamber using a flow diverter assembly (10) is disclosed. The flow diverter assembly (10) includes a movable piece (11) supported by a spring assembly (12) and a fixed outer member (13). The flow diverter assembly (10) is actuated by a fuel assembly (3) when a fuel assembly (3) is inserted into the cleaning chamber (1). The flow diverter assembly (10) acts so that the cleaning chamber (3) is supplied with suction flow (14) whenever there is a fuel assembly in the cleaning chamber (3). When a cleaning chamber (3) is empty, the flow diverter (10) acts to block the suction flow from the filtration system (15). When the cleaning chambers (1) is empty, suction pressure from the pump increases to the point that the flow diverter (10) opens sufficiently to maintain flow through the pumps to prevent the pumps from cavitating.
摘要:
The invention comprises a method for the dissolution of spent nuclear fuel pins or contaminated cladding, the method comprising contacting together the pins and both nitric and fluoroboric acids which, preferably, are present in admixture. The combination of acids dissolves both cladding and fuel at an acceptable rate and provides a solution suitable for use in subsequent purification processes such as the Purex process.