Activities of \gamma-ray emitting isotopes in rainwater from Greater Sudbury, Canada following the Fukushima incident

TL;DR

This study measured gamma-ray emitting isotopes in rainwater from Greater Sudbury, Canada, following the Fukushima nuclear accident, confirming elevated levels of certain isotopes without health risks.

Contribution

First measurement of Fukushima-related isotopes in rainwater in Canada, demonstrating the global reach of nuclear fallout detection.

Findings

Detected elevated levels of 131I, 137Cs, and 134Cs in rainwater samples.

Activities remained below health concern thresholds.

Confirmed Fukushima's radioactive fallout was detectable in Canada.

Abstract

We report the activity measured in rainwater samples collected in the Greater Sudbury area of eastern Canada on 3, 16, 20, and 26 April 2011. The samples were gamma-ray counted in a germanium detector and the isotopes 131I and 137Cs, produced by the fission of 235U, and 134Cs, produced by neutron capture on 133Cs, were observed at elevated levels compared to a reference sample of ice-water. These elevated activities are ascribed to the accident at the Fukushima Dai-ichi nuclear reactor complex in Japan that followed the 11 March earthquake and tsunami. The activity levels observed at no time presented health concerns.