Dry deposition velocity of 137Cs and 134Cs in Spain after the Fukushima Dai-Ichi Nuclear Power Plant accident.

Aerosol samples collected at the Technical University of Catalonia in Barcelona were analysed for traces of 134Cs and 137Cs emitted during the Fukushima Dai-ichi Nuclear Power Plant accident in March 2011. Samples were collected with a high-volume airborne particulate sampling system, and with a dry and wet deposition collection system for subsequent analysis. Due to the very low activities, the filters were measured in an underground ultra-low background laboratory. This has enabled the characterization of dry velocity deposition for 134Cs and 137Cs. Results show a dry velocity deposition of 0.07 cm s−1.

Validation of aerosol low-level activities by comparison with a deep underground laboratory.

The activities on air filters of the radionuclides (40)K and (137)Cs were measured in an above ground laboratory and compared with the activities measured in an underground laboratory. The average relative differences were lower than 20% for (137)Cs and (40)K. The temporal series of these radionuclides in the period 2006-2010 are also presented. These results form the baseline of these radionuclides in the studied period, and are particularly interesting because they correspond to the radioactive background in Barcelona before the Fukushima accident.

Atmospheric transport modelling of time resolved 133Xe emissions from the isotope production facility ANSTO, Australia.

The verification of the Comprehensive Nuclear-Test Ban Treaty (CTBT) relies amongst other things on the continuous and worldwide monitoring of radioxenon. The characterization of the existing and legitimate background, which is produced mainly by nuclear power plants and isotope production facilities, is of high interest to improve the capabilities of the monitoring network. However, the emissions from legitimate sources can usually only be estimated. For this paper historic source terms of (133)Xe emissions from the isotope production facility at ANSTO, Sydney, Australia, have been made available in a daily resolution. Based on these high resolution data, different source term sets with weekly, monthly and yearly time resolution have been compiled. These different sets are then applied together with atmospheric transport modelling (ATM) to predict the concentration time series at two radioxenon monitoring stations. The results are compared with each other in order to examine the improvement of the prediction capability depending on the used time resolution of the most dominant source term in the region.

Dispersion of Fukushima radionuclides in the global atmosphere and the ocean.

Large quantities of radionuclides were released in March-April 2011 during the accident of the Fukushima Dai-ichi Nuclear Power Plant to the atmosphere and the ocean. Atmospheric and marine modeling has been carried out to predict the dispersion of radionuclides worldwide, to compare the predicted and measured radionuclide concentrations, and to assess the impact of the accident on the environment. Atmospheric Lagrangian dispersion modeling was used to simulate the dispersion of (137)Cs over America and Europe. Global ocean circulation model was applied to predict the dispersion of (137)Cs in the Pacific Ocean. The measured and simulated (137)Cs concentrations in atmospheric aerosols and in seawater are compared with global fallout and the Chernobyl accident, which represent the main sources of the pre-Fukushima radionuclide background in the environment. The radionuclide concentrations in the atmosphere have been negligible when compared with the Chernobyl levels. The maximum (137)Cs concentration in surface waters of the open Pacific Ocean will be around 20 Bq/m(3). The plume will reach the US coast 4-5 y after the accident, however, the levels will be below 3 Bq/m(3). All the North Pacific Ocean will be labeled with Fukushima (137)Cs 10 y after the accident with concentration bellow 1 Bq/m(3).

Anomalies in geophysical and geochemical parameters revealed on the occasion of the Spitak (M=6.9) earthquake

On the ocasion of the Spitak earthquake (December 7, 1988) irregularities in several geophysical and geochemical parameters were revealed. In this paper data on anomalies in the water level in deep wells and in the helium content in thermal waters are presented. Data were collected from sites located in Georgia. The presented anomalies can be attributed to the processes that preceded and accompanied the earthquake; the presence of a time delay in the onset of the helium content anomalies at different sites could be an indication of the stress propagation.(AU)