Fundamental studies on extraction of actinides from spent fuels using liquefied gases - Conversion of copper into nitrate with NO2 and extraction of Nd(III) nitrate by CO2 with TBP

The nitrate conversion with liquefied NO2 and the nitrate extraction with SC-CO2 were demonstrated for copper powder and neodymium nitrate instead of actinide compounds. Copper contacted with NO2 in an autoclave at 353 K changed to water-soluble compounds. By XRD analysis of the product in the atmospheric condition, the formation of copper nitrate hydrate (Cu(NO3)2·2.5H2O) was confirmed. As for the extraction, neodymium nitrate loaded in an autoclave was successfully extracted with the fluid of TBP and SC-CO2 at 15 MPa, 313 K.