The234U/238U and235U/238U ratios from uranium compounds by -spectrometry technique have been obtained. Ten commercially available uranium reagents were analyzed. The well-separated peaks corresponding to uranium isotopes are evident, providing an energy spectrum of the -particles of uranium isotopes. It was found that some commerical uranium salts were depleted in234U and235U.
A method for isolation and electroplating of210Po is described. Natural samples of autunite, after pretreatment, were dissolved in dilute hydrochloric acid and the solution was passed through a chromatographic partition column with di (2-ethylhexyl) phosphoric acid as stationary phase. Uranium and its daughters were strongly retained in the column. The210Po fraction was eluted with citric acid solution, then evaporated almost to dryness. Next, electroplating was carried out for 18 h, at 5–10 mA current, using an electrolyte bath of oxalic acid solution. The yield of recovery of radiochemically pure210Po was about 95% of the initial210Po activity.
Authors:J. Flores-Mendoza, J. Iturbe, and M. Jimenez-Reyes
The chemical behavior of calcium, barium and radium in the ion exchange resins Dowex 50W-X8, AG 50W-X8 and Merk I in the presence of ammonium tartrate, EDTA, and citrate has been studied. No differences were observed in results while using any one of the three resins. Calcium, barium and radium were fixed to the exchange column at pH 4.8 EDTA solution. Calcium was eluted in an EDTA solution at pH 5.3, barium and radium between pH 8–11. Elution in citrate media for calcium was achieved at pH 6.1 and for radium at pH 10. In ammonium tartrate, calcium was eluted at pH 6, barium and radium at pH 11.5. Radium was also eluted from the ion exchange resins with a 2M nitric acid solution. The radium free of calcium was electrodeposited onto a stainless steel disc cathode using a 0.1 M potassium fluoride solution, pH 12–14, with a yield of >50%. The energies of226Ra were analyzed through high resolution -spectra. The226Ra utilized for these experiments was separated from Mexican carnotite.
Authors:A. Rodriguez S, B. Lopez M, and J. Iturbe G
The electrophoretic mobility of some radionuclides has been measured to understand its attractive or repulsive tendencies
towards other charged species in the medium. In this study, the chemical state of trace concentrations of88Y,103Ru,134Cs, and141Ce in the presence of UO
, as a dominant component, in strongly alkaline aqueous solutions (pH>13) was characterized.88Y and141Ce settled almost completely as colloidal species; whereas103Ru,134Cs, and uranium remained as ions. These results closely correlate a procedure for defining both the composition of the water
in contact with the fuel and the practical applicability of modified sorbents.
Authors:S. Fernández-Valverde, J. Iturbe, M. Jiménez-Reyes, and M. Monnin
A study of the isotope exchange reaction U(III)org/U(IV)aq in the extraction system: 7M HCl — tributyl phosphate (TBP) — toluene has been performed. For 20 s of contact the results show a separation factor235U/238U of 1.014. This large separation factor is explained by the oxidation reaction of235U(III) and238U(III).
Authors:B. López, A. Rodríguez S., and J. Iturbe G.
The state of trace concentrations of95Zr–95Nb and134Cs was studied at an initial pH>13 in an uranyl triperoxidate medium using the electromigration method. OH– ions governing the potential are adsorbed on the colloidal Nb(V)-hydroxide which leads to an increase in its negative electric charge; while95Zr did not move during the procedure. However, the electrophoretic mobility of the134Cs could be explained in terms of their agglomerations attributed to the interaction of Cs+ ions with water molecules to give larger aggregations.
Authors:M. Solache-Ríos, E. Ordoñez-Regil, and J. Iturbe
Lanthanum was determined in phosphoric rock and in its products obtained in the process of production of phosphoric acid and fertilizers in Mexican plants. The method used for the determination of lanthanum was neutron activation analysis. It is observed that the concentration of lanthanum is higher in the fraction of calcium salts.