Uranium-bearing phases in Hanford nuclear waste

Uranium is the most prevalent radioactive element in the 210 million liters of nuclear waste at the Hanford Site but the uranium speciation has not been determined in the waste tanks. The present study determined the common uranium-bearing solid phases in Hanford Site tank waste with X-ray diffraction and scanning electron microscopy. Sodium uranates were the most common species but uranium was also routinely co-precipitated with iron oxides. Na-U-O-P-bearing species were occasionally present. Two morphologies of sodium uranates were observed, long acicular and small spherical agglomerates up to 50 mu m in size.