Processing of Non-PFP Plutonium Oxide in Hanford Plants

Technical Report · Thu Mar 10 04:00:00 EST 2011

DOI:https://doi.org/10.2172/1015907· OSTI ID:1015907

Jones, Susan A; Delegard, Calvin H

Processing of non-irradiated plutonium oxide, PuO2, scrap for recovery of plutonium values occurred routinely at Hanford’s Plutonium Finishing Plant (PFP) in glovebox line operations. Plutonium oxide is difficult to dissolve, particularly if it has been high-fired; i.e., calcined to temperatures above about 400°C and much of it was. Dissolution of the PuO2 in the scrap typically was performed in PFP’s Miscellaneous Treatment line using nitric acid (HNO3) containing some source of fluoride ion, F-, such as hydrofluoric acid (HF), sodium fluoride (NaF), or calcium fluoride (CaF2). The HNO3 concentration generally was 6 M or higher whereas the fluoride concentration was ~0.5 M or lower. At higher fluoride concentrations, plutonium fluoride (PuF4) would precipitate, thus limiting the plutonium dissolution. Some plutonium-bearing scrap also contained PuF4 and thus required no added fluoride. Once the plutonium scrap was dissolved, the excess fluoride was complexed with aluminum ion, Al3+, added as aluminum nitrate, Al(NO3)3•9H2O, to limit collateral damage to the process equipment by the corrosive fluoride. Aluminum nitrate also was added in low quantities in processing PuF4.

• Research Organization: Pacific Northwest National Laboratory (PNNL), Richland, WA (US)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 1015907
• Report Number(s): PNNL-20246; 830403000
• Country of Publication: United States
• Language: English

Related Subjects

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS
36 MATERIALS SCIENCE
ALUMINIUM
CALCIUM FLUORIDES
DISSOLUTION
FLUORIDES
HYDROFLUORIC ACID
NITRATES
NITRIC ACID
OXIDES
PLUTONIUM
PLUTONIUM ADDITIONS
PLUTONIUM FLUORIDES
PLUTONIUM OXIDES
PROCESSING
REPROCESSING
SCRAP
SODIUM FLUORIDES
SOLVENT EXTRACTION
STORAGE FACILITIES
TANKS
URANIUM
WASTE PROCESSING
WASTE STORAGE