This report investigates the use of solvent-solvent extraction for the secondary concentration of lead and thorium. The extraction reagents investigated in this report are: For the lead extraction: diethlyammonium diethyldithiocarbamate (DDDC) For the thorium extraction: trioctylphosphinc oxide (TOPO) and di-(2-ethylhexyl)phosphoric add (HDEHP). For all of the extractions 2-octanone was used as...

The soil-mushroom transfer of thorium and uranium was analyzed in two ecologically similar but geographically separated Spanish ecosystems by means of the transfer factor, TF. Uranium TF values were in the range 0.043-0.49, and thorium TF values in the range 0.030-0.62. These values were similar to those of (90)Sr, (239+240)Pu, and (241)Am found previously in the same ecosystems. Given the low ...

Electrospray-mass spectrometry (ES-MS) has been used for the first time to study the hydrolysis of thorium. Hence, important discrepancies exist in the literature concerning the appearance of the first hydroxo complex. By studying thorium species as a function of pH, it was possible to observe the appearance of the first thorium hydroxo complexes at pH 1 as well as the other hydroxo complexes a...

Oxidation of a ~1000Å sputter-deposited thorium thin film at 150°C in 100ppm of flowing oxygen in argon produces the long-sought solid form of thorium monoxide. Changes in the scattering length density (SLD) distribution in the film over the 700 min experiment measured by in-situ, dynamic neutron reflectometry (NR) shows the densities, compositions and thickness of the various thorium oxides la...

Brazilian systematic investigations on the use of thorium fuel cycles in nuclear power reactors started in 1965. During the 60's and early 70's the work was mainly concentrated on the thorium utilization in heavy water reactors (HWRs). This work was performed in the framework of a cooperation agreement with the, French CEA. In the frame of the International Nuclear Fuel Cycle program, Brazil st...

Our previous studies on water cooled thorium breeder reactor based on matured pressurized water reactor (PWR) plant technology concluded that reduced moderated core by arranging fuel pins in a triangular tight lattice array and using heavy water as coolant is appropriate for achieving better breeding performance and higher burn-up simultaneously [1–6]. One optimum core that produces 3.5 GW ther...