Stories from Physics for 11-14 14-16 16-19
Following the Fukushima nuclear disaster in Japan in 2011, researchers developed an unusual method for monitoring radiation levels using coins. They estimated the exposure of areas surrounding the nuclear plant to neutron radiation by collecting 5-yen coins from homes 100-500 m from the facility. The coins are composed of 37% zinc by weight and, when exposed to neutrons, the zinc-65 isotope is produced which decays with a half-life of 244 days with the emission of gamma rays. The researchers could calculate the intensity of neutron radiation at different distances from the plant by analysing the proportion of zinc isotopes in the coins.