What+were+the+events+that+led+to+the+crisis+in+the+reactor?

==﻿What were the events that led to the crisis in the reactor ==

By: Chae Yeong, Hae Ji, Rosie, Tooie, So Yeon, Van
= Japan earthquake and tsunami = = ﻿ =

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__Happening:__ An explosion on Tuesday damaged the suppression pool, into which steam is vented from the reactor to relieve pressure. Reactor building roof damaged and fuel rods fully exposed - 33% are damaged. Sea water being pumped in to cool them. =====

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__Happening:__ This reactor is top priority because it has the highest radiation levels - it is the only one using plutonium in fuel mix. Sea water being pumped in to cool rods. Explosion hit reactor building on Monday. Helicopter bid to drop water on reactor was scrapped because radiation levels were too high. Spent fuel pool temperature has risen to 60C from usual 30-40C, but this isn't critical. =====

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__Happening:__ Reactor had been shut down for maintenance. TV on Wednesday showed smoke or steam rising from the facility after flames were seen earlier. On Tuesday, a pool where spent fuel is stored caught fire and caused an explosion. Blast punctured two 8m-square holes in wall of outer housing. Workers must wait two days to pour water into the pool because of high radiation levels. =====

Events that lead to Fukushima Nuclear Incident:

 * TEPCO (Tokyo Energy Power Company) told the Nuclear and Industrial Safety Agency: In 1991 and 1992 the company "falsified the results of safety test on the containment vessel of the No.1 reactor, which is now one of three reactors that workers are struggling to keep from overheating."
 * In 2003 TEPCO shut down all of the reactors after "acknowledging the systematic cover up of inspection data showing cracks on the reactors."
 * In 2007, after an earthquake, TEPCO Kashiwazaki-Kariwa plant spilled radioactive water into the Sea of Japan and it released radiation into the atmosphere, but TEPCO told the public no radiation have been released.
 * In July 17, 2010, a reactor at Fukushima 1 lost its electricity, a dangerous drop in cooling water happened as a result.
 * In 2011, an earthquake of 8.9 magnitude and a tsunami knocked out the electricity that powers the cooling system in the reactors. Scientists have detected cesium-137 and iodine-131, two highly radioactive isotopes outside the plant. This is a clear signal showing that two or more of the reactor cores are seriously damaged and at least partially melted.



Websites:
"Japan Nuclear Crisis: What is Happening to Reactors inside Fukushima?" //Japan// //Nuclear Crisis: What is Happening to Reactors inside Fukushima?// Mirror.com, 17 Mar. 2011. Web. 31 Mar. 2011. .

Tapper, Jake. "Japan: Events Leading Up to Fukushima Nuclear Disaster." ABC News. ABC News, 16 Mar. 2011. Web. 31 Mar. 2011. <[] japan-events-leading-up-to-the-fukushima-nuclear-disaster.html>.

West, Larry. "Earthquake and Tsunami Lead to Nuclear Crisis in Japan." About Environment Issue. About.com, 14 Mar. 2011. Web. 31 Mar. 2011. <[]>.

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