Japan's Tokyo Electric Power Corporation (TEPCO) has identified and categorized all possible risks that might have an impact outside the site boundary of the Fukushima Daiichi Nuclear Power Station following the detection of a puddle of highly contaminated water discovered at the rooftop of the Unit 2 record building on 24 February 2015. Japan's Ministry of Foreign Affairs distributed information on the result of the comprehensive risk review to all embassies, consular missions and international organizations in Japan today.
The risk review identified 190 target items, 124 of which were classified either as countermeasure in practice, needing follow-up observation or needing no additional measures. Of the remaining 66 items, 21 were classified as needing necessary countermeasures, one of which needed immediate countermeasures, and 45 were classified as needing further examination.
The background and nature of the comprehensive risk review is explained in page 4 of the attached document.