After the March 11, 2011 tsunami, TEPCO knew within three days that reactor fuel damage exceeded 25-55% — well above the 5% meltdown threshold under their own manual. But TEPCO president instructed officials not to use the word 'meltdown,' instead describing the situation as 'core damage' for two months. This wasn't their first cover-up: in 2002, TEPCO admitted to 200 occasions of falsifying safety reports over 25 years (1977-2002), including hiding cracks in reactor core shrouds detected as early as 1993.