– Kyodo: Robot data reveals hole in Unit 2 suspected to be almost 10 square cm; Highly radioactive water draining out bottom of containment vessel — Tepco model shows molten fuel barely underwater — Temperature irregulaties started earlier this month (GRAPHIC) (ENENews, Jan 30, 2014):
Kyodo News, Jan. 30, 2014: Fukushima No. 2 reactor suppression pool may have 3-cm hole — The suppression pool connected to the No. 2 reactor at the disaster-struck Fukushima Daiichi nuclear power plant may have a 3-centimeter hole through which highly radioactive water is leaking out, the plant operator said Thursday. Tokyo Electric Power Co. said data gathered by a robot this month near the doughnut-shaped suppression pool at the bottom of the No. 2 reactor’s primary containment vessel indicated that the structure is damaged somewhere. […] TEPCO estimated the damaged section could be 8 to 9 square cm in size. If it were a hole, it is expected to be between 3.2 and 3.6 cm in diameter.
A previous estimation by Japan government experts determined there was a hole over 30 times larger: 300 square centimeter hole in Reactor No. 2 pressure suppression pool: NISA analysis
The line indicating temperature in Unit 2 began to deviate from Units 1 and 3 earlier this month:
Information regarding how the hole may have been created: NHK: “The unimaginable was happening” — Workers say part of Reactor 2 containment vessel destroyed — After alarming pressure readings, “we heard a loud bang… pressure is now zero” (VIDEO)