摘要:
The invention relates to a process for reprocessing a spent nuclear fuel and for preparing a mixed uranium-plutonium oxide, which process comprises: a) the separation of the uranium and plutonium from the fission products, the americium and the curium that are present in an aqueous nitric solution resulting from the dissolution of the fuel in nitric acid, this step including at least one operation of coextracting the uranium and plutonium from said solution by a solvent phase; b) the partition of the coextracted uranium and plutonium to a first aqueous phase containing plutonium and uranium, and a second aqueous phase containing uranium but no plutonium; c) the purification of the plutonium and uranium that are present in the first aqueous phase; and d) a step of coconverting the plutonium and uranium to a mixed uranium/plutonium oxide. Applications: reprocessing of nuclear fuels based on uranium oxide or on mixed uranium-plutonium oxide.
摘要:
The invention relates to a method for separating uranium (VI) from one or several types of actinide selected from actinides (IV) and actinides (VI) other than uranium (VI), consisting a) in bringing into contact an organic phase which is insoluble in water and contains said uranium and one or several actinides with an acid aqueous solution containing at least a lacunar heteropolyanion and, if said actinide or one of said actinides is an actinide (VI), a reducing agent for selectively reducing said actinide (VI) and b) in separating the organic phase from the aqueous solution. Said invention can be used for reprocessing irradiated nuclear fuels and for processing rare-earth minerals, thorium and/or uranium.
摘要:
The invention relates to a method for treating spent nuclear fuel, which includes (a) decontaminating the uranium, plutonium and neptunium found in a nitric aqueous phase resulting from dissolving said nuclear fuel in HNO 3 , with regard to the actinides (III) and the majority of the fission products also found in said phase, said decontamination including at least the co-extraction of the uranium, plutonium and neptunium in a solvent phase; (b) splitting the uranium, plutonium and neptunium found in the solvent phase in a first aqueous phase containing either plutonium with no U or Np, or a mixture of Pu and U with no Np, or a mixture of Pu, U and Np, and a second aqueous phase containing either a mixture of U and Np with no Pu, or uranium with no P or Np; (c) storing the first aqueous phase; (d) purifying the plutonium or the mixture of Pu and U or the mixture of Pu, U and Np found in the first aqueous phase relative to the fission products still found in said phase, said purification including at least one addition of uranium, in order to obtain, at the end of said purification, an aqueous solution containing a mixture of Pu and U or Pu, U and Np; and (e) co-converting the resulting mixture of Pu and U or the mixture of Pu, U and Np into a mixed oxide.