Oxidative dissolution of plutonium dioxide in nitric acid in the presence of ozone. II. Overall process of dissolution. Sulfuric acid containing systems
- Khlopin Radium Inst., St. Petersburg (Russian Federation)
A kinetic study is made of the oxidative dissolution of plutonium dioxide calcined at 600-800 and 1600{degrees}C in nitric acid in the presence of ozone. Interphase reaction PuO{sub 2} + Ce(IV) is the limiting stage of the dissolution of low-calcined PuO{sub 2} at (PuO{sub 2}){sub O} {le} 5x10{sup {minus}3} mol 1{sup {minus}1} solvent. In the case of systems containing sulfuric acid, the same is true for (PuO{sub 2}){sub O} {le} 1x10{sup {minus}4} mol 1{sup {minus}1} solvent. With (PuO{sub 2}){sub O} = 0.08-0.85 mol 1{sup {minus}1} standard solvent (4 M HNO{sub 3} + (1-3) x 10{sup {minus}2}M Ce + 1.5 x 10{sup {minus}2}M H{sub 2}SO{sub 4}) and at t = 70-92{degrees}C, the limiting stage of the process is interphase oxidation of cerium (III) with ozone and/or ozone transfer through the gas-solution interface. For high-calcined PuO{sub 2}, linear dependences on plutonium dioxide weight per liter of the solvent in the system are established for both the apparent rate constant of the process and cerium(IV) concentration: k= (1.19 {plus_minus}0.09) x 10{sup {minus}2}(PuO{sub 2}){sub O}, mol{sup {minus}1} 1{sup {minus}1} s{sup {minus}1}; (Ce(IV)) = (1.4{plus_minus}0.1) x 10 {sup {minus}2}-(9.21{plus_minus}1.4) x 10{sup {minus}2}(PuO{sub 2}), M.
- OSTI ID:
- 171780
- Journal Information:
- Radiochemistry, Vol. 37, Issue 3; Other Information: PBD: Jul-Aug 1995; TN: Translated from Radiokhimiya; 37: No. 3, 221-227(1995)
- Country of Publication:
- United States
- Language:
- English
Similar Records
Ozone transfer through the gas-solution interface during oxidative dissolution of plutonium dioxide
Recovery of plutonium from HEPA filters by Ce(IV)-promoted dissolution of PuO/sub 2/ and recycle of the cerium promoter