AbstractA Modified Zirflex process was developed in the laboratory for dissolution of 1–10 % uranium-zirconium alloy fuels clad in Zircaloy-2 to produce a nitrate solution from which uranium can be recovered by conventional solvent extraction methods. A flowsheet is presented for dissolution of 7% uranium-zirconium alloy in 5.4MNH4F-0.33MNH4NO3. Enough 1 M H2O2is added continually during dissolution to yield 0.13MH2O2in the final solution, neglecting the amount reacting. Dissolution of a 70-mil thick sample is complete in 1 hr. The solvent extraction feed is prepared by adding aluminum nitrate and nitric acid to the dissolver solution to yield a stable solvent extraction feed solution of 0.0075Muranium, 0.25Mzirconium, 1Maluminum, 2Mfluoride, and 1Mnitric acid. The off-gas is approximately 98.5% NH6, 1% H2, 0.3% O2, and 0.2% N2. Conventional stainless steel such as 309SNb or Hastelloy F appear to be suitable materials of construction with corrosion rates varying from 0.1 to 3.0 mils/month.