Nearly five years after the nation's worst nuclear accident, Tokyo Electric Power Co. has admitted that its staff failed to follow damage assessment guidelines, according to which they should have reported the meltdowns almost immediately.
A Tepco spokesman on Wednesday said the company's Disaster Management Manual requires a reactor to be declared "in meltdown" if 5 percent or more of its fuel rods are determined to be "damaged."
Tepco knew the extent of the damage early on. As of March 14, 2011, it estimated that 55 percent of the fuel rod assemblies of the reactor No. 1 and 25 percent of those at reactor No. 3 were "damaged," based on the levels of radiation detected, Tepco spokesperson Yukako Handa told The Japan Times by phone.