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Aerosol collections were initiated at several locations by Pacific Northwest National Laboratory (PNNL) shortly after the Great East Japan earthquake of May 2011. Aerosol samples were transferred to laboratory high-resolution gamma spectrometers for analysis. Similar to treaty monitoring stations operating across the Northern hemisphere, iodine and other isotopes which could be volatilized at high temperature were detected. Though these locations are not far apart, they have significant variations with respect to water, mountain-range placement, and local topography. Variation in computed source terms will be shown to bound the variability of this approach to source estimation. [ABSTRACT FROM AUTHOR]

Two independent radionuclide aerosol air samplers were operated at Pacific Northwest National Laboratory in close proximity during the Fukushima reactor releases. One system was an automated aerosol collection and analysis unit, whereas the other was a manual sampler of simpler design. The samples collected from each sampler showed correlation in radionuclide activity, although some variations were observed. During this unique event, the small variations observed between the co-located air samplers illustrate the effectiveness of a way to acquire useful parallel samples for scientific purposes. The results in radionuclide activity concentration show that, in some circumstances, use of a manual high volume air sampler in parallel to a complex automated sampler can produce results that are of comparable quality to International Monitoring System samples. [ABSTRACT FROM AUTHOR]

Abstract: We report on the first measurements of short-lived gaseous fission products detected outside of Japan following the Fukushima nuclear releases, which occurred after a 9.0 magnitude earthquake and tsunami on March 11, 2011. The measurements were conducted at the Pacific Northwest National Laboratory (PNNL), (46°16′47″N, 119°16′53″W) located more than 7000 km from the emission point in Fukushima Japan (37°25′17″N, 141°1′57″E). First detections of 133Xe were made starting early March 16, only four days following the earthquake. Maximum concentrations of 133Xe were in excess of 40 Bq/m3, which is more than ×40,000 the average concentration of this isotope is this part of the United States. [Copyright &y& Elsevier]