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

TL;DR

This study reports on the detection and quantification of Fukushima-derived airborne fission products in Chapel Hill, NC, over 62 days, using high-purity germanium detectors to measure specific isotopes in air samples.

Contribution

First measurement of Fukushima-related airborne fission products in North Carolina using high-sensitivity gamma-ray detection over an extended period.

Findings

Detected I-131 and Cs-137 with specific activity levels

Measured additional isotopes including I-132, Cs-134, Cs-136, and Te-132

Provided data on the dispersion of radioactive materials from Fukushima

Abstract

We present measurements of airborne fission products in Chapel Hill, NC, USA, from 62 days 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 I-131 and Cs-137 were measured with maximum activities of 4.2 +/- 0.6 mBq/m^3 and 0.42 +/- 0.07 mBq/m^3 respectively. Additional activity from I-131, I-132, Cs-134, Cs-136, Cs-137 and Te-132 were measured in the same air filters using a low-background HPGe detector at the Kimballton Underground Research Facility (KURF).