IMPROVED METHOD TO PROCESS SPENT NUCLEAR FUEL Russian patent published in 2015 - IPC G21C19/46 

FIELD: physics, nuclear.

SUBSTANCE: invention relates to the method of processing of spent nuclear fuel. The proposed method includes treatment of uranium, plutonium and neptunium available in nitric acid water phase produced by dissolution of the specified nuclear fuel in HNO₃, from admixtures of actinides (III) and most part of fission products, also available in this phase, besides, the specified treatment from admixtures includes at least joint extraction of uranium, plutonium and neptunium in the dissolvent phase; division of uranium, plutonium and neptunium available in the dissolvent phase into the first water phase that contains either plutonium without U or Np, or a mixture of Pu+U without Np, or a mixture of Pu+U+Np, and the second water phase comprising either a mixture of U+Np without Pu, or uranium without Pu and Np; storage of the first water phase; treatment of plutonium or a mixture of Pu+U, or a mixture of Pu+U+Np, available in the first water phase, from fission products, still available in this phase, at the same time the specified treatment includes at least single addition of uranium to produce a water solution at the end of this stage, containing a mixture of Pu+U or Pu+U+Np; and joint conversion of thus produced mixture of Pu+U or Pu+U+Np into mixed oxide.

EFFECT: possibility to exclude present of treated plutonium, even mixed with uranium or uranium and neptunium, in place of processing of spent nuclear fuel.

36 cl, 3 dwg