2010s List of civilian nuclear accidents

after 2011 tōhoku earthquake , tsunami of march 11, emergency power supply of fukushima-daiichi nuclear power plant failed. followed deliberate releases of radioactive gas reactors 1 , 2 relieve pressure.






on march 12, triggered falling water levels , exposed fuel rods, hydrogen explosion occurred @ reactor 1, resulting in collapse of concrete outer structure. although reactor containment confirmed intact, hourly radiation plant reached 1.015 sv (101.5 rem) - amount equivalent allowable ordinary people in 1 year.






residents of fukushima area advised stay inside, close doors , windows, turn off air conditioning, , cover mouths masks, towels or handkerchiefs not drink tap water. evening of march 12, exclusion zone had been extended 20 kilometres (12 mi) around plant , 70,000 80,000 people had been evacuated homes in northern japan.






on march 14, second, hydrogen explosion (nearly identical first explosion in unit 1) occurred in reactor building unit 3, similar effects.






on march 15, third explosion occurs in “pressure suppression room” of unit 2 , said not have breached reactor’s inner steel containment vessel, later reports indicated explosion damaged steel containment structure of unit 2 , larger releases of radiation expected previously.






on march 15, fourth explosion damages 4th floor area above reactor , spent fuel pool of unit 4 reactor. contrary tepco press release, aerial photos show of outer building destroyed. fuel rods (both new , spent fuel) of reactor unit 4, stored in exposed spent fuel pool, reportedly exposed air – have risked melting of nuclear fuel. however, later research found fuel rods had been covered water time.






on 16 march tepco estimated 70% of fuel in unit 1 had melted, , 33% in unit 2, further suspecting unit 3 s core might damaged. in november 2011 tepco released report of modular accident analysis program (maap). report showed reactor pressure vessel (rpv) in unit 1 (commonly known reactor core) had been damaged during disaster, , significant amounts of fuel had fallen bottom of primary containment vessel (pcv) – erosion of concrete of pcv molten fuel after disaster estimated have been stopped in approx. 0.7 metres (2 ft 4 in) depth, thickness of containment being 7.6 metres (25 ft). gas sampling done before report detected no signs of ongoing reaction of fuel concrete of pcv , fuel in unit 1 estimated cooled down, including fuel dropped on bottom of reactor . maap further showed fuel in unit 2 , unit 3 had melted, less unit 1, , fuel presumed still in rpv, no significant amounts of fuel fallen bottom of pcv. report further suggested there range in evaluation results fuel in rpv (some fuel in pcv) in unit 2 , unit 3, fuel in rpv (none fuel fallen pcv) . unit 2 , unit 3 estimated fuel cooled sufficiently . larger damage in unit 1 according report due long time cooling water no injected in unit 1, letting more decay heat accumulate – 1 day there no water injection unit 1, while unit 2 , unit 3 had quarter of day without water injection. of december 2013, reported tepco estimated unit 1 decay heat must have decreased enough, molten fuel can assumed remain in pcv (primary container vessel) .






^ yuri kageyama; ryan nakashima (april 12, 2011). japan ups nuke crisis severity match chernobyl . associated press. retrieved april 12, 2011. 
^ iaea briefing on fukushima nuclear accident (12 april 2011, 14:30 utc) . april 12, 2011. 
^ tepco confirms partial fuel rod meltdown @ plant . bbc news. may 24, 2011. 
^ nuclear accident rated @ level 4 . nhk world. retrieved march 12, 2011. 
^ 福島第一原発爆発の瞬間 nuclear power station explosion fukushima japan . youtube. retrieved march 12, 2011. 
^ fox news channel breaking news alert (live tv coverage), 3:00 am est, march 12
^ live blog, bbc news, march 12, 2011
^ fredrik dahl; louise ireland (march 12, 2011). hydrogen may have caused japan atom blast-industry . reuters. retrieved march 12, 2011. 
^ explosion heard @ quake-hit reactor . nhk world. march 12, 2011. 
^ world nuclear news (march 12, 2011). battle stabilise earthquake reactors . world nuclear news. retrieved march 12, 2011. 
^ japan fill leaking nuke reactor sea water . reuters. march 12, 2011. 
^ explosion @ fukushima reactor 1; 4 injured, 3 irradiated (japanese)
^ explosion @ quake-hit nuclear plant . abc news (australian broadcasting corporation). march 12, 2011. retrieved march 12, 2011. 
^ see also: radiation dose limits . bbc.co.uk. retrieved march 12, 2011. 
^ glendinning, lee (march 12, 2011). japan tsunami , earthquake - live coverage | world news | guardian.co.uk . london: guardian. retrieved march 12, 2011. 
^ japan earthquake | page 18 | liveblog live blogging | reuters.com . live.reuters.com. february 9, 2009. retrieved march 12, 2011. 
^ nhk news 7 (tv coverage), march 13, 2011, 10:46 utc
^ blast, cooling system breakdown spread fears of nuclear radiation . cnn. march 14, 2011. 
^ hiroko tabuchi; keith bradsher; matt wald (march 14, 2011). japan faces prospect of nuclear catastrophe workers leave plant . new york times. 
^ plant operator says reactor seal apparently not holed . channelnewsasia.com. march 15, 2011. 
^ damage unit 4 nuclear reactor building @ fukushima dai-ichi nuclear power station (press release). tokyo electric power company. 15 march 2011. retrieved 26 february 2013. 
^ hiroko tabuchi, keith bradsher,david e. sanger matthew l. wald (march 15, 2011). fire , damage @ japanese plant raise risk of nuclear disaster . new york times. cs1 maint: multiple names: authors list (link)
^ http://www.tepco.co.jp/en/nu/fukushima-np/images/handouts_120516_07-e.pdf
^ fukushima timeline scientificamerican.com
^ evaluation status of reactor core damage @ fukushima daiichi nuclear power station units 1 3 november 30, 2011 tokyo electric power company
^ of fuel not remaining in reactor1 core / tepco “but molten fuel stopped in concrete base” fukushima-diary.com