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Tri- n-butyl phosphate (TBP) is the key complexant within the plutonium and uranium reduction extraction process used to extract uranium and plutonium from used nuclear fuel. During reprocessing TBP degrades to dibutyl phosphate (DBP), butyl acid phosphate (MBP), butanol, and phosphoric acid over time. A method for rapidly monitoring TBP degradation is needed for the support of nuclear forensics. Therefore, a Fourier transform infrared spectrometry-attenuated total reflectance (FTIR-ATR) technique was developed to determine approximate peak intensity ratios of TBP and its degradation products. The technique was developed by combining variable concentrations of TBP, DBP, and MBP to simulate TBP degradation. This method is achieved by analyzing selected peak positions and peak intensity ratios of TBP and DBP at different stages of degradation. The developed technique was tested on TBP samples degraded with nitric acid. In mock degradation samples, the 1,235 cm peak position shifts to 1,220 cm as the concentration of TBP decreases and DBP increases. Peak intensity ratios of TBP positions at 1,279 and 1,020 cm relative to DBP positions at 909 and 1,003 cm demonstrate an increasing trend as the concentration of DBP increases. The same peak intensity ratios were used to analyze DBP relative to MBP whereas a decreasing trend is seen with increasing DBP concentrations. The technique developed from this study may be used as a tool to determine TBP degradation in nuclear reprocessing via a rapid FTIR-ATR measurement without gas chromatography analysis. [ABSTRACT FROM AUTHOR]

The Bothnian Sea which is located between Finland and Sweden represents an important source of fresh water to the Baltic Sea. We here present new data on the radioactive isotope I species from water samples collected in December 2009 at different depths in the Bothnian Sea. Concentrations of I (iodide) in the Bothnian Sea range from 14 × 10 to 32 × 10 atoms/L, while IO (iodate) concentrations are relatively low and fluctuating at 1 × 10 atoms/L. For nutrients data determined in the same samples as I, significant correlations could be found between I and total P, NO-N, SiO-Si, but rather poor with NH-N. The correlations suggest comparable source pathway of I and nutrient parameters, while the source of NH-N may be different. The small amounts and negligible change of IO indicate prevailing extensive reduction of iodate in the Baltic Sea. [ABSTRACT FROM AUTHOR]

Tc is an important radionuclides related to repository safety assessment. The mobility pertechnetate (TcO) can be reduced to immobility technetium(IV) hydrous oxides (TcO· nHO) by Fe(II)-bearing minerals. In China, Gaomiaozi (GMZ) bentonite is regarded as the favorable candidate backfilling material for the HLW repository, which is contained some FeO. The diffusion behavior of Tc was investigated in GMZ bentonite by through- and out-diffusion methods. The effective diffusion coefficient ( D), the accessible porosity (ε), apparent diffusion coefficient ( D) and distribution coefficient ( K) were decreased with the increasing of dry density. The D values were (2.8 ± 0.2) × 10 m/s and (3.5 ± 0.2) × 10 m/s at dry density of 1,600 and 1,800 kg/m, respectively. It was indicated that the dominating species was TcO during the diffusion processing. While, out-diffusion results showed that part of TcO may be reduced by Fe(II). The relationship of D and ε could be described by Archie's law with exponent n = 2.4 for Tc diffusion in GMZ bentonite. Furthermore, the relationship between D and dry density (ρ) was exponential. [ABSTRACT FROM AUTHOR]

The present study involves the screening of silver nanoparticles containing carbonized yeast cells isolated from coconut cell sap for efficient adsorption of few long lived radionuclides like Cs, Co, Ru, Pu and Am. Yeast cells containing silver nanoparticles produced through biological reduction were subjected to carbonization (400 °C for 1 h) at atmospheric conditions and their properties were analyzed using fourier transform infra-red spectroscopy, X-ray diffraction, scanning electron microscope attached with energy dispersive spectroscopy and transmission electron microscope. The average size of the silver nanoparticles present on the surface of the carbonized silver containing yeast cells (CSY) was 19 ± 9 nm. The carbonized control yeast cells without silver exposure (CCY) did not contain any particles on its surface. The efficiency of CSY and CCY towards the radionuclide adsorption was studied in batch mode at fixed contact time, concentration, and at its native pH. CSY was efficient in removal of Pu (76.75%) and Ru (54.73%) whereas CCY showed efficient removal only for Am (62.89%). Both the adsorbents did not show any retention with respect to Co and Cs. Based on the experimental data, decontamination factor and distribution coefficient ( K) were calculated and, from the values, it was observed that these adsorbents have greater potential to adsorb radionuclides. [ABSTRACT FROM AUTHOR]