The Nuclear Regulation Authority's latest criticism of Tokyo Electric Power Co. came a day after the operator of the Fukushima Dai-ichi nuclear plant acknowledged that the 300-ton (300,000-liter, 80,000-gallon) leak probably began nearly a month and a half before it was discovered Aug. 19.
In a meeting with agency officials Tuesday night, TEPCO said radioactivity near the leak and exposure levels among patrolling staff started to increase in early July. There is no sign that anyone tried to find the source of that radioactivity before the leak was discovered.