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Abstract: Results of radioactivity measurements in Bratislava aerosols following the Fukushima accident showed that at least three radioactive plumes arrived to Bratislava as indicated by 131I/137Cs activity ratios. When compared with the Chernobyl results available for the Bratislava station, the Fukushima radionuclide levels were almost five orders of magnitude lower, with the maximum values for 131I and 137Cs of 0.5 and 0.07 mBq/m3, respectively. The 131I and 137Cs vs. 7Be aerosol activity records showed that the increases in 131I and 137Cs activity concentrations were accompanied by 7Be increases, indicating that both the horizontal and vertical transports of radionuclides were responsible for observed radionuclide concentrations. The 134Cs/137Cs activity ratio was close to 1, as has also been reported by other investigators. [Copyright &y& Elsevier]

Abstract: Anthropogenic radionuclides (3 H, 14 C, and 129I) stemmed from nuclear weapons tests were found in 1999 to be very abundant in the surface of the southern Indian Ocean, comparable to those in the subtropical Northwest Pacific Ocean. The observed radionuclide variations with latitude/longitude in the southern Indian Ocean are not due to deposition patterns of global fallout, but due to transport of water masses from the western Pacific through the Indonesian seas, and different water fronts present in the Crozet Basin of the Indian Ocean. High radionuclide concentrations observed in the latitudinal belt of 20-40°S are associated with the Indian Ocean Subtropical Gyre which acts as a reservoir of radionuclides, maintaining their high concentrations on a time scale of several decades. 14 C data documents that the southern Indian Ocean is an important for sink of anthropogenic carbon. The isotopic tracers reveal the evidence of the most intense surface gradients and presence of several water masses in the southern Indian Ocean, which makes the region one of the most dynamic places of the World Ocean. [ABSTRACT FROM AUTHOR]

Abstract: Anthropogenic radionuclides have been widely used to investigate water circulation on regional and global scales. We observed that 3H, 14C, 90Sr and 129I concentrations in surface water of the Indian Ocean are similar to those measured in the North-western Pacific Ocean. This is due to the transport of water masses from the North-western Pacific via the Indonesian Seas to the Indian Ocean. The observed variations of radionuclide concentrations with latitude in the Indian Ocean are not due to deposition patterns of global fallout, but due to different water masses present in the region. Higher radionuclide concentrations observed in the South Indian Ocean in the latitudinal belt of 20–40°S are associated with the Indian Ocean Subtropical gyre, which acts as a reservoir of radionuclides. [Copyright &y& Elsevier]

A reference material designed for the determination of anthropogenic and natural radionuclides in sediment, IAEA-384 (Fangataufa Lagoon sediment), is described and the results of certification are presented. The material has been certified for 8 radionuclides (40K, 60Co, 155Eu, 230Th, 238U, 238Pu, 239+240Pu and 241Am). Information values are given for 12 radionuclides (90Sr, 137Cs, 210Pb (210Po), 226Ra, 228Ra, 232Th, 234U, 235U, 239Pu, 240Pu and 241Pu). Less reported radionuclides include 228Th, 236U, 239Np and 242Pu. The reference material may be used for quality management of radioanalytical laboratories engaged in the analysis of radionuclides in the environment, as well as for the development and validation of analytical methods and for training purposes. The material is available from IAEA in 100 g units. [ABSTRACT FROM AUTHOR]

As a follow up to the initial 1998 intercomparison study, a second study was initiated in 2001 as part of the ongoing evaluation of the capabilities of various ultra-sensitive methods to analyze239Pu in urine samples. The initial study1was sponsored by the Department of Energy, Office of International Health Programs to evaluate and validate new technologies that may supersede the existing fission tract analysis (FTA) method for the analysis of239Pu in urine at theµBq/l level. The ultra-sensitive techniques evaluated in the second study included accelerator mass spectrometry (AMS) by LLNL, thermal ionization mass spectrometry (TIMS) by LANL and FTA by the University of Utah. Only the results for the mass spectrometric methods will be presented. For the second study, the testing levels were approximately 4, 9, 29 and 56µBq of239Pu per liter of synthetic urine. Each test sample also contained240Pu at a240Pu/239Pu atom ratio of ~0.15 and natural uranium at a concentration of 50µBq/ml. From the results of the two studies, it can be inferred that the best performance at theµBq level is more laboratory specific than method specific. The second study demonstrated that LANL-TIMS and LLNL-AMS had essentially the same quantification level for both isotopes. Study results for bias and precision and acceptable performance compared to ANSI N13.30 and ANSI N42.22 have been compiled. [ABSTRACT FROM AUTHOR]

Two Martian meteorites, Chassigny and Nakhla, were analyzed by non-destructive gamma-ray spectrometry to determine concentrations of cosmogenic (26Al) and primordial (40K, 238U, 232Th) radionuclides, and to estimate their pre-atmospheric sizes and cosmic-ray exposure ages. The pre-atmospheric radii of the Chassigny and Nakhla meteorites were estimated using the cosmogenic 26Al to be 17 ​± ​4 and 30 ​± ​5 ​cm, which would result in their total masses of 30–130 and 210–580 ​kg, respectively. This is comparable to the size and mass estimated for other chassignites and nakhlites. The cosmic-ray exposure ages of the Chassigny and Nakhla meteorites estimated using the 26Al – 21Ne isotope pair were 12.8 ​± ​2.5 and 11.6 ​± ​1.8 Myr, respectively, in agreement with published ages of chassignites and nakhlites averaged from several isotope methods, i.e. 11.6 ​± ​0.8 and 12.2 ​± ​0.8 Myr, respectively. • Two Martian meteorites, Chassigny and Nakhla, were analyzed by non-destructive gamma-ray spectrometry. • Pre-atmospheric radii of the Chassigny and Nakhla were estimated to be 17 ​± ​4 and 30 ​± ​5 ​cm, respectively. • Cosmic-ray exposure ages of the Chassigny and Nakhla were estimated to be 12.8 ​± ​2.5 and 11.6 ​± ​1.8 Myr, respectively. • The obtained results are in agreement with published ages of chassignites and nakhlites. [ABSTRACT FROM AUTHOR]

Cosmogenic radionuclides produced by galactic cosmic rays (GCR) in meteorites during their motion in space are natural detectors of the GCR intensity and variations along the meteorite orbits. On the basis of measured and calculated contents of cosmogenic radionuclides in the freshly fallen Chelyabinsk and Košice chondrites some peculiarities of generation of cosmogenic radionuclides of different half-lives in the chondrites of different orbits and dates of fall onto the Earth are demonstrated. Dependence of production rates of the radionuclides on the GCR variations in the heliosphere is analyzed. Using radionuclides with different half-lives it is possible to compare the average GCR intensity over various time periods. The measurement and theoretical analysis of cosmogenic radionuclides in consecutively fallen chondrites provide a unique information on the space–time continuum of the cosmogenic radionuclide production rates and their variations over a long time scale, which could be useful in correlative analyses of processes in the heliosphere. Some applications of cosmogenic radionuclide depth distribution in chondrites for estimation of their pre-atmospheric sizes are illustrated. [ABSTRACT FROM AUTHOR]

Abstract: Analyses of 131I, 137Cs and 134Cs in airborne aerosols were carried out in daily samples in Vilnius, Lithuania after the Fukushima accident during the period of March–April, 2011. The activity concentrations of 131I and 137Cs ranged from 12 μBq/m3 and 1.4 μBq/m3 to 3700 μBq/m3 and 1040 μBq/m3, respectively. The activity concentration of 239,240Pu in one aerosol sample collected from 23 March to 15 April, 2011 was found to be 44.5 nBq/m3. The two maxima found in radionuclide concentrations were related to complicated long-range air mass transport from Japan across the Pacific, the North America and the Atlantic Ocean to Central Europe as indicated by modelling. HYSPLIT backward trajectories and meteorological data were applied for interpretation of activity variations of measured radionuclides observed at the site of investigation. 7Be and 212Pb activity concentrations and their ratios were used as tracers of vertical transport of air masses. Fukushima data were compared with the data obtained during the Chernobyl accident and in the post Chernobyl period. The activity concentrations of 131I and 137Cs were found to be by 4 orders of magnitude lower as compared to the Chernobyl accident. The activity ratio of 134Cs/137Cs was around 1 with small variations only. The activity ratio of 238Pu/239,240Pu in the aerosol sample was 1.2, indicating a presence of the spent fuel of different origin than that of the Chernobyl accident. [Copyright &y& Elsevier]

Abstract: A new Certified Reference Material (CRM) for radionuclides in sediment (IAEA-385) is described and the results of the certification process are presented. Eleven radionuclides (40K, 137Cs, 226Ra, 228Ra, 230Th, 232Th, 234U, 238U, 238Pu, 239+240Pu and 241Am) have been certified and information mass activities with 95% confidence intervals are given for seven other radionuclides (90Sr, 210Pb(210Po), 235U, 239Pu, 240Pu and 241Pu). Results for less frequently reported radionuclides (60Co, 99Tc, 134Cs, 155Eu, 224Ra and 239Np) and information on some activity and mass ratios are also reported. The CRM can be used for quality assurance/quality control of the analysis of radionuclides in sediment samples, for the development and validation of analytical methods and for training purposes. [Copyright &y& Elsevier]

Abstract: A certified reference material (CRM) for radionuclides in fish sample IAEA-414 (mixed fish from the Irish Sea and North Seas) is described and the results of the certification process are presented. Nine radionuclides (40K, 137Cs, 232Th, 234U, 235U, 238U, 238Pu, 239+240Pu and 241Am) were certified for this material. Information on massic activities with 95% confidence intervals is given for six other radionuclides (90Sr, 210Pb(210Po), 226Ra, 239Pu, 240Pu 241Pu). Less frequently reported radionuclides (99Tc, 129I, 228Th, 230Th and 237Np) and information on some activity and mass ratios are also included. The CRM can be used for quality assurance/quality control of the analysis of radionuclides in fish sample, for the development and validation of analytical methods and for training purposes. The material is available from IAEA, Vienna, in 100g units. [Copyright &y& Elsevier]

The present plutonium and 137Cs concentrations in South Pacific Ocean surface waters were determined. The water samples were collected in the South Pacific mid-latitude region (32.5 °S) during the BEAGLE expedition conducted in 2003–04 by JAMSTEC. 239,240Pu concentrations in surface seawater of the South Pacific were in the range of 0.5 to 4.1 mBq m−3, whereas 137Cs concentrations ranged from 0.07 to 1.7 Bq m−3. The observed 239,240Pu and 137Cs concentrations in the South Pacific were almost of the same level as those in the North Pacific subtropical gyre. The surface 239,240Pu in the South Pacific subtropical gyre showed larger spatial variations than 137Cs, as it may be affected by physical and biogeochemical processes. The 239,240Pu/137Cs activity ratios, which reflect biogeochemical processes in seawater, were generally smaller than that observed in global fallout, except for the most eastern station. The 239,240Pu/137Cs ratios in the South Pacific tend to be higher than that in the North Pacific. The relationships between anthropogenic radionuclides and oceanographic parameters such as salinity and nutrients were examined. The 137Cs concentrations in the western South Pacific (the Tasman Sea) and the eastern South Pacific were negatively correlated with the phosphate concentration, whereas there is no correlation between the 137Cs and nutrients concentrations in the South Pacific subtropical gyre. The mutual relationships between anthropogenic radionuclides and oceanographic parameters are important for better understanding of transport processes of anthropogenic radionuclides and their fate in the South Pacific. [Copyright &y& Elsevier]

The Modane underground laboratory (LSM) is the deepest operating underground laboratory in Europe. It is located under the Fréjus peak in Savoie Alps in France, with average overburden of 4800 m w. e. (water equivalent), providing low-background environment for experiments in nuclear and particle physics, astrophysics and environmental physics. It is crucial to understand individual sources of background such as residual cosmic-ray flux of high-energy muons, muon-induced neutrons and contributions from radionuclides present in the environment. The identified dominant sources of background are radioactive contamination of construction materials of detectors and laboratory walls, radon contamination of the laboratory air, and neutrons produced in the laboratory. The largest neutron contribution has been identified from (α, n) reactions in low Z materials (10−7-10−4 n s−1 Bq−1) and from spontaneous fission of 238U (1.1 × 10−6 n s−1 Bq−1). • Individual background contributions in the Modane underground laboratory are discussed. • Natural radioactive contamination in the detector construction and laboratory environment is the dominant background source. • Neutrons coming from the (α, n) reactions and spontaneous fission have been identified as the dominant neutron background sources. • Muon induced neutrons contribute less than 1% to neutron flux. [ABSTRACT FROM AUTHOR]

In February 2004, anthropogenic radionuclides (137Cs, 236U, 239Pu and 240Pu), transported from the Sahara Desert, were observed in the Monaco air, and later in water and sediment samples collected at the DYFAMED site in the northwest (NW) Mediterranean Sea. While 236U and 137Cs in Saharan dust particles showed a high solubility in seawater, Pu isotopes were particle reactive in the water column and in the sediment. The impact of the Saharan deposition was found at 0–1.0 cm of the sediment core for 236U and 137Cs, and between 1.0 and 1.5 cm for Pu isotopes. The excess of 236U was observed more in the water column than in the sediment, whereas the 239+240Pu total inventories were comparable in the water column and the sediment. This single-day particle event represented 72% of annual atmospheric deposition in Monaco. At the DYFAMED site, it accounted for 10% (137Cs) and 15% (239+240Pu) activities of sinking particles during the period of the highest mass flux collected at the 200 and 1000 m water depths, and for a significant proportion of the total annual atmospheric input to the NW Mediterranean Sea (28–37% for 137Cs and 34–45% for 239+240Pu). Contributions to the total 137Cs and 239+240Pu sediment inventories were estimated to be 14% and 8%, respectively. The Saharan dust deposition phenomenon (atmospheric input, water column and sediment) offered a unique case to study origin and accumulation rates of radionuclides in the NW Mediterranean Sea. • Impact of Saharan dust events on radionuclide levels. • Gamma-spectrometry and Accelerator Mass Spectrometry. • Radionuclides in the NW Mediterranean Sea. • Sediment core DYFAMED station. • 137Cs, 236U, Pu isotopes budget estimation. [ABSTRACT FROM AUTHOR]