Evaluation of neutron dose released in the environment by activation of gold

Kushita, Kohei; Atarashi-Andoh, Mariko  ; Amano, Hikaru*

We report here the study of activated gold for the estimation of neutron dose in the environment in the case of JCO criticality accident happened in Tokai, Japan, in 1999. We collected and analyzed 16 gold samples, such as ring, coin or necklace stored at residents houses in the range from 168 to 568 m from the accident place of JCO. They gave activities from 91.9 to 0.322 Bq/g-Au as standardized values at 06:15, Oct. 1, 1999, when the criticality reaction had ceased after 20 hours of continuation. The induced radioactivity of gold samples showed a good correlation as a power function of distance. The induced radioactivity of gold is discussed with reference data to estimate dose equivalent in the environment around JCO. This paper gives an example showing the usefulness of gold in the field of nuclear and radiation studies and applications.