In the era of hyper-connected world, a catastrophe in one country is broadcasted live and can affect policies in other countries. The 2011 Fukushima Daiichi nuclear disaster in Japan is one such prominent case that influenced many countries. Based on analyzing 158,964 tweets generated over a 4-year period, this paper presents a model of risk perception on radiological accidents in Japan's nearest neighbor,
Korea. We explain the process through which continual media broadcasts of foreign risks (i.e., disaster in Japan) become perceived by Korean social media users as internal risks and hence call for agenda setting and participation at a societal level. Our model empirically presents a mechanism that could transmit perception and awareness towards risk across cultural boundaries.