TOKYO -- Tokyo Electric Power Co. said yesterday that fuel rods melted in two more reactors at its Fukushima nuclear plant, indicating for the first time that damage from the March 11 earthquake and tsunami is matching worst-case scenarios.
Fuel rods in reactors 2 and 3 had almost complete meltdowns, spokesman Junichi Matsumoto told reporters in Tokyo yesterday. That's in line with U.S. assessments in the early days of the crisis that suggested damage to the station was more severe than Tokyo Electric officials estimated.
The meltdown of the cores is the "greatest at the No. 1 reactor, followed by the No. 3 unit and then No. 2," Matsumoto said. The analysis of the damage became possible "after data from the central control room was retrieved."
Japan's biggest utility, known as Tepco, raised the possibility of more extensive destruction when it announced last week -- more than two months after the disaster -- that fuel rods in the No. 1 reactor had melted within 16 hours of the quake and cooling water was below the base of the rods.
"When Tepco announced there wasn't any water in the No. 1 reactor pressure vessel, the speculation was that had also happened in No. 2 and No. 3 reactors," said Ken Nakajima, a professor of nuclear engineering who specializes in reactor safety. "Now they have confirmed what everyone expected."
Tepco has been struggling to cool reactors and spent fuel pools to stop radiation leaks and resolve the world's worst nuclear crisis since Chernobyl in 1986. On April 17 it set out a so-called road map to end the crisis in six to nine months.
The utility said it expects to achieve a sustained drop in radiation levels at the plant within three months, followed by a cold shutdown, where core reactor temperatures fall below 100 degrees Celsius.
It repeated the timetable last week in an update of the plan, drawing criticism from Tetsuo Ito, head of the Atomic Energy Research Institute at Kinki University in western Japan.
Setting a timetable without knowing the condition of the reactor cores doesn't make sense, Ito said in a phone interview from Osaka.