Solvent performance in THTR nuclear fuel reprocessing. II. On the formation of dibutyl phosphoric acid by radiolytic and hydrolytic degradation of the TBP-n-paraffin extractant

Journal Article · Mon Aug 01 00:00:00 EDT 1977 · Nucl. Technol.; (United States)

OSTI ID:7287761

Brodda, B G; Heinen, D

Radiolysis and hydrolysis of tributylphosphate (TBP) in n-paraffin diluent were investigated under conditions simulating several parameters of the THOREX flowsheet for reprocessing thorium containing spent nuclear fuel. The solvent (30 vol% TBP-n-paraffin) was equilibrated with 0.25 to 3 molar nitric acid, and the organic phase was inspected by gas chromatography. Radiolysis in pure solvents (30 and 5 vol% TBP-n-paraffin) with doses from 0.5 to 13 Wh . l/sup -1/ produces HDBP with G values (TBP-based) of approx. 2 and approx. 6, slightly decreasing with higher doses. No H/sub 2/MBP was found. Radiolysis in solvent (30 vol% TBP-n-paraffin), equilibrated with 0.25 to 3 molar nitric acid at a constant dose of 7 Wh . l/sup -1/, leads to a considerably reduced radiolytic fraction of the total HDBP yield with a minimum of approx. 0.3 molar nitric acid in the organic phase (2 molar in the aqueous phase). Irradiating the solvent (30 vol% TBP-n-paraffin), equilibrated with 0.75 molar nitric acid (0.12 molar in the organic phase) with doses from 0.5 to 13 Wh . l/sup -1/, leads to a mixture of hydrolytically and radiolytically formed HDBP, the hydrolytic fraction of which raises the total HDBP yield over the radiolytic HDBP yield from acid-free solvents up to doses of approx. 3 Wh . l/sup -1/. It is proposed to denominate TBP degradation product yields according to their origin, hydrolysis or radiolysis (G value), or just by a concentration value in case of mixed origin, valid for the experimental conditions.

• Research Organization: Kernforschungsalage, Juelich, Ger.
• OSTI ID: 7287761
• Journal Information: Nucl. Technol.; (United States), Vol. 34:3
• Country of Publication: United States
• Language: English

Related Subjects

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS
38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY
DBP
G VALUE
PARAFFIN
HYDROLYSIS
RADIOLYSIS
TBP
NITRIC ACID
ORGANIC SOLVENTS
PERFORMANCE
RADIATION DOSES
REPROCESSING
SPENT FUELS
THOREX PROCESS
ALKANES
BUTYL PHOSPHATES
CHEMICAL RADIATION EFFECTS
CHEMICAL REACTIONS
CHEMISTRY
DECOMPOSITION
DOSES
ENERGY SOURCES
ESTERS
FUELS
HYDROCARBONS
HYDROGEN COMPOUNDS
INORGANIC ACIDS
LYSIS
NUCLEAR FUELS
ORGANIC COMPOUNDS
ORGANIC PHOSPHORUS COMPOUNDS
OTHER ORGANIC COMPOUNDS
PHOSPHORIC ACID ESTERS
RADIATION CHEMISTRY
RADIATION EFFECTS
REACTOR MATERIALS
SEPARATION PROCESSES
SOLVENTS
SOLVOLYSIS
WAXES
050800* - Nuclear Fuels- Spent Fuels Reprocessing
400600 - Radiation Chemistry