Since the Fukushima nuclear disaster in 2011, more than 100 citizen radiation detection labs have been established in Japan. In this talk, Kim addresses how citizen labs produce, circulate, and contest radiation detection data not only to understand the safety in the environment but also to archive the environmental injustice created by the nation-state and nuclear industry. In exploring radiation contamination after the disaster, citizen labs investigate how nuclear crises have affected the more-than-human environment (Haraway 2015; Tsing 2013) beyond anthropocentric accounts. This project also asks how citizens expand their understanding regarding nuclear crises beyond Fukushima through radiation detection activities.