Characterization of radioactive particles using non-destructive alpha spectrometry

Spherical particles with known properties were used to demonstrate and test a novel software package known as AASIFIT, which is able to unfold complex alpha spectra. A unique feature of the program is that it uses simulated peak shapes in the fitting process. The experimental reference particles in the testing were artificially produced U particles of diameter 1.4 mm and a nuclear bomb particle with a twenty-fold greater diameter, mainly composed of U and Pu dioxides. AASIFIT was used to determine the density of the U particles. In addition, the activities of 239+240Pu and 241Am were determined for the nuclear bomb particle and compared to earlier determinations in the literature. The results of this investigation demonstrated that the software can be used to estimate the properties of particles emitting alpha radiation. However, the composition and geometry of the investigated particles need to be known with good accuracy for reliable estimates. Furthermore, uncertainties in the stopping power data, especially for U and Pu, may have an influence on the results obtained from the software.JRC.E.7-Nuclear Safeguards and Forensic

Characterization of radioactive particles using non-destructive alpha spectrometry.

Spherical particles with known properties were used to demonstrate and test a novel software package known as AASIFIT, which is able to unfold complex alpha spectra. A unique feature of the program is that it uses simulated peak shapes in the fitting process. The experimental reference particles in the testing were artificially produced U particles of diameter 1.4mum and a nuclear bomb particle with a twenty-fold greater diameter, mainly composed of U and Pu dioxides. AASIFIT was used to determine the density of the U particles. In addition, the activities of (239+240)Pu and (241)Am were determined for the nuclear bomb particle and compared to earlier determinations in the literature. The results of this investigation demonstrated that the software can be used to estimate the properties of particles emitting alpha radiation. However, the composition and geometry of the investigated particles need to be known with good accuracy for reliable estimates. Furthermore, uncertainties in the stopping power data, especially for U and Pu, may have an influence on the results obtained from the software

Nondestructive spectrometric study on a radioactive particle embedded in a marine sediment

A radioactive particle embedded in a sediment collected from the Irish Sea was examined with spectrometric methods to understand the potential bioavailability of its constituents. Images of the particle surface were acquired in the backscattering mode by scanning electron microscopy. The elemental composition of the particle surface layer was measured using energy dispersive ~SEM-EDX! and wavelength dispersive ~SEM-WDX! X-ray spectrometers. The investigation showed that the sample consists of a calcite matrix in which uranium is present in the form of separate inclusions. The diameter of U inclusions was less than 10 mm. Synchrotron radiation based X-ray fluorescence in confocal geometry ~confocal m-XRF! was used to determine the spatial distribution of elements in the particle. Three-dimensional reconstructions of the Ca, Cr,Mn, Fe, Zn, Sr, Ba, Pb, and U distributions were performed. The oxidation state of uranium in the different inclusions was determined by synchrotron radiation based X-ray absorption in confocal geometry ~confocal m-XANES!. The isotopic composition of uranium was measured by secondary ion mass spectrometry. The results revealed that uranium was depleted in 235U. Pu and other actinides were not detected.JRC.E.5-Nuclear chemistr

Influence of releases of 129I and 137Cs from European reprocessing facilities in Fucus vesiculosus and seawater from the Kattegat and Skagerrak areas

129I is a very long-lived radionuclide (T1/2=15.7×106 years) that is present in the environment because of natural and anthropogenic sources. Compared to the pre-nuclear era, large amounts of 129I have been released to the marine environment, especially as liquid and gaseous discharges from two European reprocessing facilities located at Sellafield (England) and La Hague (France). The marine environment, i.e., the oceans, is the major source of iodine. Brown seaweed accumulates iodine at high levels up to 1.0% of dry weigh, and therefore they are ideal bioindicators for studying levels of 129I. In this work, 129I concentrations have been determined in seaweed Fucus vesiculosus and seawater collected in the Kattegat and Skagerrak areas in July 2007. The resulting data were evaluated in terms of 129I concentrations and 129I/137Cs ratios. 129I concentrations were found to be in the order of (44-575)×109atomsg-1 in seaweed and (5.4-51)×109atomsg-1 in seawater, with an enhancement in the Skagerrak area in comparison to the Kattegat area. Iodine-129 concentrations in both seaweed and seawater were used to determine the concentration factor of iodine in brown seaweed F. vesiculosus. The high levels of 129I and 129I/137Cs ratios in the Skagerrak area and their gradually decreasing trend to the Kattegat indicates that the most important contribution to the 129I inventory in those areas comes from Sellafield and La Hague reprocessing plants. © 2014 Elsevier Ltd.The authors would like to thank the Swedish Radiation Protection Authority (SSM), Spanish Ministry of Science and Technology (FIS2008-01149, FIS2012-31853) and the Junta de Andalucía (EXC/2005/RNM-419) for their financial support.Peer Reviewe

Abernethy Malformation Type II in a 70-Year-Old Patient with Angina Pectoris

Congenital extrahepatic portosystemic shunts (ECPSS) are rare developmental anomalies in which a variable portion of the portal blood bypasses the liver and is shunted in the systemic circulation via one or more aberrant vessels. We present a clinical case of a 70-year-old man, who was referred to the Cardiology Department because of exertional dyspnea, fatigue, and feeling of heaviness and pressure behind the sternum. MDCT of the aorta was performed and an aberrant vessel was discovered with communication with the left iliac vein on one side and superior mesenteric and splenic veins on the other. The portal vein was hypoplastic. The radiologic findings were suggestive of malformation of Abernethy. The ECPSS can be classified into 2 main groups (with complete and partial shunting). The patients have different clinical presentation. Some of them are completely asymptomatic while in others the shunt can manifest even before birth as fetal growth retardation or in the early neonatal period with neonatal cholestasis and galactosemia. Common complications are hepatic encephalopathy and hepatopulmonary syndrome and there is a wide variety of concomitant abnormalities. The imaging modalities play a crucial role in the diagnosis, classification, follow-up and the proper choice of therapeutic management in patients with ECPSS

Influence of releases of 129I and 137Cs from European reprocessing facilities in Fucus vesiculosus and seawater from the Kattegat and Skagerrak areas

129I is a very long-lived radionuclide (T1/2 = 15.7 × 106 years) that is present in the environment because of natural and anthropogenic sources. Compared to the pre-nuclear era, large amounts of 129I have been released to the marine environment, especially as liquid and gaseous discharges from two European reprocessing facilities located at Sellafield (England) and La Hague (France). The marine environment, i.e., the oceans, is the major source of iodine. Brown seaweed accumulates iodine at high levels up to 1.0% of dry weigh, and therefore they are ideal bioindicators for studying levels of 129I. In this work, 129I concentrations have been determined in seaweed Fucus vesiculosus and seawater collected in the Kattegat and Skagerrak areas in July 2007. The resulting data were evaluated in terms of 129I concentrations and 129I/137Cs ratios. 129I concentrations were found to be in the order of (44–575) × 109 atoms g−1 in seaweed and (5.4–51) × 109 atoms g−1 in seawater, with an enhancement in the Skagerrak area in comparison to the Kattegat area. Iodine-129 concentrations in both seaweed and seawater were used to determine the concentration factor of iodine in brown seaweed F. vesiculosus. The high levels of 129I and 129I/137Cs ratios in the Skagerrak area and their gradually decreasing trend to the Kattegat indicates that the most important contribution to the 129I inventory in those areas comes from Sellafield and La Hague reprocessing plants.Ministerio de Ciencia y Tecnología FIS2008-01149Ministerio de Ciencia y Tecnología FIS2012-31853Junta de Andalucía EXC/2005/RNM-41