By Mari Yamaguchi
TOKYO, Japan (AP) – A rat causing a power outage by short-circuiting a temporary switchboard. Another blackout occurring as workers install anti-rat nets. Holes in the linings of huge underground tanks leaking radioactive water.
Japan’s crippled Fukushima Dai-ichi nuclear power plant has run into multiple problems recently that highlight its precarious state more than two years after its reactors melted down in the wake of a devastating earthquake and tsunami.
A makeshift system of pipes, tanks and power cables meant to carry cooling water into the melted reactors and spent fuel pools inside shattered buildings remains highly vulnerable, Nuclear Regulation Authority chairman Shunichi Tanaka acknowledged.
“Fukushima Dai-ichi is still in an extremely unstable condition, there is no mistake about that,” Tanaka said at a weekly meeting of the regulatory body’s leaders. “We cannot rule out the possibility that similar problems might occur again. Whenever a problem occurs, it halts the plant’s operations and delays the primary goal of decommissioning the plant.”
The problems have raised doubts about whether the plant can stay intact through a decommissioning process that could take 40 years, prompting officials to compile risk-reduction measures and revise decommissioning plans. The regulatory watchdog said Wednesday that it was increasing the number of inspectors from eight to nine to better oversee the plant.
Just over the past three weeks, there have been at least eight accidents or problems at the plant, the nuclear watchdog said.
The first was March 18, when a rat sneaked into an outdoor switchboard – which was sitting on a pickup truck – powering the jury-rigged cooling system and several other key parts of the plant, causing a shortcircuit and blackout that lasted 30 hours in some areas of the plant. Four storage pools for fuel rods lost cooling during the outage, causing Tokyo Electric Power Co., the plant’s operator, to acknowledge that it had added backup power only to the reactors, despite repeated concerns raised over a pool meltdown.1 2 next >>