Official 'cold shutdown condition' was announced in mid-December. After two weeks, the three reactors (units 1-3) were stable with water addition and by July they were being cooled with recycled water from the new treatment plant.All four Fukushima Daiichi reactors were written off due to damage in the accident – 2719 MWe net.The accident was rated level 7 on the International Nuclear and Radiological Event Scale, due to high radioactive releases over days 4 to 6, eventually a total of some 940 PBq (I-131 eq).All three cores largely melted in the first three days. Following a major earthquake, a 15-metre tsunami disabled the power supply and cooling of three Fukushima Daiichi reactors, causing a nuclear accident beginning on 11 March 2011.
