By simulation experiments with a 10–5 mol/l solution of iodododecane labeled with131I in n-dodecane the influence of various materials and conditions, which are possible in nuclear fuel reprocessing, has been investigated. The formation of decomposition products was detected via HPLC with a radioactivity monitor. By means of252Cf plasma-desorption mass spectrometry (PDMS) the decomposition products were identified. It was found that a temperature of 100°C favored the formation of iodoalkanes with chain lengths of C1 to C11. The presence of TBP(tri-n-butyl-phosphate) accelerated the decomposition of iodododecane. In pure TBP only iodobutane was formed as a decomposition product.
Authors:O. Kindel, F. Herrmann, L. Schmidt, and P. Patzelt
In kerosene samples from nuclear fuel reprocessing, iodoalkanes with chain-lengths from C4 to C13 have been identified. The kerosene samples were purified by means of solid-phase extraction. By this method other fission products like125Sb and106Ru were quantitatively removed from the solution. The only remaining radioactive nuclide was thus129I. The iodoorganic compounds in the kerosene from the solvent were enriched from 6000 Bq/L to 100 000 Bq/L129I by vacuum distillation. Chromatographic separation by HPLC, fractionation, and -measurement of the fractions showed that at least one polar and one nonpolar iodoorganic compound were present. Derivatisation of the iodoorganic compounds with, 1,4-diazabicyclo-2,2,2-octane to quatermary ammonium salts and252Cf plasma desorption mass spectrometry of the products revealed that the main iodoorganic constituents in the kerosene were iodobutane as polar and iodododecane as nonpolar compound in approximately equal concentrations.
Authors:O. Kindel, V. Hoeflich, F. Herrmann, and P. Patzelt
A 10–5 mol 1–1 solutiopn of idododecane in n-dodecane was used to simulate a kerosene sample from nuclear fuel reporcessing. Several methods were developed for the quantitative removal of iodododecane from the n-dodecane solution. Decomposition to elemental iodine was achieved either by washing with hyperazeotropic nitric acid or by exposure to a high-intensity UV-light. Quantitative removal of iodododecane from n-dodecane was achieved by absorption on silver nitrate impregnated materila or on activated charcoal, which was impregnated with potassium thiocyanate or 1,4-diazabicyclo-2,2,2-octance. The reaction could be accelerated by stirring or heating. Thus a quantitative absorption of idododecane could be achieved within a few minutes. The results of the experiments were confirmed by absorption of iodoorganic compounds from kerosene of the Karl sruhe nuclear fuel reprocessing plant (WAK) on the tested material.