This document discusses open and user innovations that occurred in response to the 2011 Fukushima nuclear crisis in Japan. It describes how individuals and communities reacted in three main ways: 1) By sharing information on social media to disseminate updates and form projects. 2) By making official radiation data more accessible and understandable through open data initiatives and visualizations. 3) By creating crisis maps and hardware like Geiger counters to collect and map radiation levels across Japan. These grassroots efforts helped fill information gaps and give people a better sense of the risks when official sources provided limited or unclear information.