From the Mainichi Daily News:
At least two reactors at the crippled Fukushima No. 1 Nuclear Power Plant may have holes in their containment vessels, according to a report released by Tokyo Electric Power Co. (TEPCO) on May 24, a finding that could hamper efforts to meet a government-sanctioned timetable to end the crisis.
TEPCO, the operator of the troubled nuclear power plant, said in the report that meltdowns had occurred at the No. 1, 2 and 3 reactors. The report revealed for the first time the possibility of the No. 1 and 2 reactors having a hole about 7 centimeters in diameter and multiple holes about 10 centimeters in diameter in their respective containment vessels.
TEPCO said the damage caused by meltdowns to the pressure vessels of the No. 2 and 3 reactors was "limited." But experts had questioned the status of their pressure vessels as well as their containment vessels because highly contaminated radioactive water was leaked into their turbine buildings. Therefore, it has become increasingly unclear whether the utility and the government can deliver on the roadmap that seeks to bring the nuclear power plant under control within six to nine months.