Timeline of the Fukushima Daiichi nuclear disaster of caesium-137 by the Atmospheric Chemistry and Physics journal—an estimate about 42 percent of that released into the atmosphere in the Chernobyl explosion in 1986. Caesium-137 has a half-life of 30 years. TEPCO reports the completion of a cover for the reactor unit 1, which is 54 metres high, 47 metres wide and 42 metres deep. The cover has a built-in ventilation system that is supposed to filter radioactive material. Boric acid is injected into reactor number 2 after the discovery of xenon in its containment vessel. The presence of xenon may be an indication that a self-sustained fission reaction
Radiation effects from the Fukushima Daiichi nuclear disaster Professor at Stanford, there were some meteorological effects involved and that "81 percent of all the emissions were deposited over the ocean" instead of mainly being spread inland. Seawater containing measurable levels of iodine-131 and caesium-137 were collected by Japan Agency for Marine-Earth Science and Technology (JAMSTEC) on 22–23 March at several points 30 km from the coastline iodine concentrations were "at or above Japanese regulatory limits" while caesium was "well below those limits" according to an IAEA report on 24 March. On 25 March, IAEA indicated that in the long term, caesium-137 (with a half-life of 30 years) would