Author: D. CrossleyPublisher:
ISBN:
Category :
Languages : en
Pages : 16
Book Description
The dissolution of plutonium dioxide in hydrochloric acid at high temperature and pressure
The Dissolution of Plutonium Dioxide in Hydrochloric Acid at High Tempertature and Pressure
Author: A Kinetic Study of Plutonium Dioxide Dissolution in Hydrochloric Acid Using Iron (II) as an Electron Transfer Catalyst
Author: Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Effective dissolution of plutonium dioxide has traditionally been accomplished by contact with strong nitric acid containing a small amount of fluoride at temperatures of [approximately] 100 C. In spite of these aggressive conditions, PuO[sub 2] dissolution is sometimes incomplete requiring additional contact with the solvent. This work focused on an alternative to conventional dissolution in nitric acid where an electron transfer catalyst, Fe(II), was used in hydrochloric acid. Cyclic voltammetry was employed as an in-situ analytical technique for monitoring the dissolution reaction rate. The plutonium oxide selected for this study was decomposed plutonium oxalate with> 95% of the material having a particle diameter (
Dissolution of Plutonium Dioxide Using HCl-HF.
Author: Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
High-fired PuO2 (950° to 1700°C) can be dissolved in boiling 6.1 M HCl when the fluoride ion concentration to plutonium mole (F−/Pu) ratio is>0.5. The amount of PuO2 (950°C calcined oxide) dissolved in 1 hour increased from approx.0.2% to 66%, 91%, and 100% as the F−/Pu ratio increased from 0 to 0.5, 1.0, and 1.8, respectively. The PuO2 dissolution rates in HCl-CaF2 solutions decrease with increasing oxide calcination temperatures and decreasing oxide surface areas. At a F−/Pu ratio of 1.8, the 1700°C calcined oxide was completely dissolved in 2.5 hours versus 1 hour for the 950°C calcined oxide.
Dissolution of Plutonium Oxide in Nitric Acid at High Hydrofluoric Acid Concentrations
Author: Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
The dissolution of plutonium dioxide in nitirc acid (HNO3) at high hydrofluoric acid (HF) concentrations has been investigated. Dissolution rate curves were obtained using 12M HNO3 and HF at concentrations varying from 0.05 to 1.0 molar. The dissolution rate increased with HF concentration up to 0.2M and then decreased at higher concentrations. There was very little plutonium dissolved at 0.7 and 1.0M HF because of the formation of insoluble PuF4. Various oxidizing agents were added to 12M HNO3-1M HF dissolvent to oxidize Pu(IV) to Pu(VI) and prevent the formation of PuF4. Ceric (Ce(IV)) and silver (Ag(II)) ions were the most effective in dissolving PuO2. Although these two oxidants greatly increased the dissolution rate, the rates were not as rapid as those obtained with 12M HNO3-0.2M HF.
A Review of the Dissolution of Plutonium Dioxide
Author: W. S. GilmanPublisher:
ISBN:
Category : Bibliography
Languages : en
Pages : 14
Book Description
Dissolution of Plutonium Oxide in Nitric Acid at High Hydrofluoric Acid Concentrations
Author: Armen R. KazanjianA Kinetic Study of Plutonium Dioxide Dissolution in Hydrochloric Acid Using Iron (II) as an Electron Transfer Catalyst
Author: Keith William FifePublisher:
ISBN:
Category : Metallic oxides
Languages : en
Pages : 410
Book Description
Plutonium Dissolution Process
Author: Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
A two-step process for dissolving plutonium metal, which two steps can be carried out sequentially or simultaneously. Plutonium metal is exposed to a first mixture containing approximately 1.0M-1.67M sulfamic acid and 0.0025M-0.1M fluoride, the mixture having been heated to a temperature between 45.degree. C. and 70.degree. C. The mixture will dissolve a first portion of the plutonium metal but leave a portion of the plutonium in an oxide residue. Then, a mineral acid and additional fluoride are added to dissolve the residue. Alteratively, nitric acid in a concentration between approximately 0.05M and 0.067M is added to the first mixture to dissolve the residue as it is produced. Hydrogen released during the dissolution process is diluted with nitrogen.
Purification of Aqueous Plutonium Chloride Solutions Via Precipitation and Washing
Author: Publisher:
ISBN:
Category :
Languages : en
Pages : 7
Book Description
Pyrochemical operations at Los Alamos Plutonium Facility (TA-55) use high temperature melt s of calcium chloride for the reduction of plutonium oxide to plutonium metal and hi gh temperature combined melts of sodium chloride and potassium chloride mixtures for the electrorefining purification of plutonium metal . The remaining plutonium and americium are recovered from thes e salts by dissolution in concentrated hydrochloric acid followed by either solvent extraction or io n exchange for isolation and ultimately converted to oxide after precipitation with oxalic acid . Figur e 1 illustrates the current aqueous chloride flow sheet used for plutonium processing at TA-55.