Processing of Non-PFP Plutonium Oxide in Hanford Plants

Jones, Susan A. ; Delegard, Calvin H.

关键词: 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;   

DOI  :  10.2172/1015907
RP-ID  :  PNNL-20246
PID  :  OSTI ID: 1015907
Others  :  Other: 830403000
Others  :  TRN: US1102968

美国|英语

来源: SciTech Connect

【 摘 要 】

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.