The Japanese tsunami and resulting nuclear emergency at the Fukushima Daiichi power facility: technical, radiologic, and response perspectives

The Fukushima Daiichi nuclear power facility, in the Futaba District of the Fukushima Prefecture in Japan, was severely damaged by the earthquake and ensuing tsunami that struck off the northern coast of the island of Honshu on March 11, 2011. The resulting structural damage to the plant disabled the reactor's cooling systems and led to significant, ongoing environmental releases of radioactivity, triggering a mandatory evacuation of a large area surrounding the plant. The status of the facility continues to change, and permanent control of its radioactive inventory has not yet been achieved. The purpose of this educational article is to summarize the short-term chronology, radiologic consequences, emergency responses, and long-term challenges associated with this event. Although there is ongoing debate on preparedness before the event and the candor of responsible entities in recognizing and disclosing its severity, it largely appears that appropriate key actions were taken by the Japanese authorities during the event that should mitigate any radiologic health impact. These actions include an organized evacuation of over 200,000 inhabitants from the vicinity of the site and areas early in the emergency; monitoring of food and water and placement of radiation limits on such foodstuffs; distribution of stable potassium iodide; and systematic scanning of evacuees. However, the risk of additional fuel damage and of further, perhaps substantial, releases persists. The situation at the Fukushima Daiichi nuclear facility remains fluid, and the long-term environmental and health impact will likely take years to fully delineate.