Measurement of airborne fission products in Chapel Hill, NC, USA from the Fukushima Dai-ichi reactor accident

We present measurement results of airborne fission products in Chapel Hill, NC, USA, from 62 d following the March 11, 2011, accident at the Fukushima Dai-ichi nuclear power plant. Airborne particle samples were collected daily in air filters and radio-assayed with two high-purity germanium (HPGe) detectors. The fission products 131I and 137Cs were measured with maximum activity concentrations of 4.2 ± 0.6 mBq/m3 and 0.42 ± 0.07 mBq/m3 respectively. Additional activity from 131,132I, 134,136,137Cs and 132Te were measured in the same air filters using a low-background HPGe detector at the Kimballton Underground Research Facility (KURF).

► We measured airborne fission products following the Fukushima nuclear accident.
► A sensitive HPGe detector was used to search for more exotic fission products.
► We measured a maximum of 4.2 mBq/m3 I-131 and 0.42 mBq/m3 Cs-137.
► Measured radioactivity is below government limits for iodine and cesium.