Detection of 133Xe from the Fukushima nuclear power plant in the upper troposphere above Germany

Abstract

After the accident in the Japanese Fukushima Dai-ichi nuclear power plant in March 2011 large amounts of radioactivity were released and distributed in the atmosphere. Among them were also radioactive noble gas isotopes which can be used as tracers to test global atmospheric circulation models. This work presents unique measurements of the radionuclide 133 Xe from Fukushima in the upper troposphere above Germany. The measurements involve air sampling in a research jet aircraft followed by chromatographic xenon extraction and ultra-low background gas counting with miniaturized proportional counters. With this technique a detection limit of the order of 100 133 Xe atoms in litre-scale air samples (corresponding to about 100 mBq/m 3 ) is achievable. Our results provide proof that the 133 Xe-rich ground level air layer from Fukushima was lifted up to the tropopause and distributed hemispherically. Moreover, comparisons with ground level air measurements indicate that the arrival of the radioactive plume at high altitude over Germany occurred several days before the ground level plume.

Radioactivity impacts of the Fukushima Nuclear Accident on the atmosphere

“…The total radioactivity in the atmosphere was about 1~100 Bq/m 3 , which was mainly 107 attributed to radon ( 220 Rn and 222 Rn) and their progenies. The peak radioactivity in the atmosphere including 85 Kr, 108 133 Xe, 131 I, 134 Cs, 137 Cs derived from the FNA in Japan was larger than 1000 Bq/m 3 , which was about three orders 109 of magnitude higher than that in other countries excluding Japan due to physical decay, atmospheric dilution and 110 wet/dry deposition (Thakur et al, 2013;Simgen et al, 2014). The peak value of total atmospheric radioactivity 111 derived from the FNA was mainly from radioactive noble gases in the early phase of the accident, which could be 112 about two orders of magnitude higher than the radioactive background of the atmosphere in Japan and be 113…”

Radon depletion in xenon boil-off gas

“…The miniaturized proportional counters used in this work have been originally developed for the GALLEX solar neutrino experiment [19]. They were furthermore used to measure traces of noble gases, e.g., 133 Xe in air samples [20] and to study the 222 Rn emanation rate of detector materials with a sensitivity of 40 µBq [21]. In order to determine the radon reduction in boil-off xenon, gas samples are taken from a sample port installed after the radon monitor (see Fig.…”

PENGARUH PARAMETER PROSES ELEKTRODEPOSISI TERHADAP PENENTUAN BERAT ISOTOP 235U DALAM PEB U3Si2/Al PASCA IRADIASI

“…Bahan bakar U3Si2/Al pasca iradiasi mengandung beberapa hasil fisi seperti isotop 137 Cs, 144 Ba, dan 90 Sr dan unsur bermassa berat diantaranya adalah isotop 238 U, 235 U , 234 U, 236 U, 239 Pu, dan 238 Pu. Isotop 144 Ba adalah isotop hasil fisi yang masih dapat meluruh dan menghasilkan isotop lain sebagai hasil fisi yang lebih stabil yaitu 90 Sr dan 137 Cs [2,3] . Hasil fisi sebagai pemancar radiasi gamma harus dipisahkan dari unsur-unsur bermassa berat sebagai pemancar radiasi sinar alpha.…”