The mangled wreckage of the construction crane at the Takahama nuclear power plant in Takahama, Fukui Prefecture, on Jan. 21 (Hiroomi Utsuno)

TAKAHAMA, Fukui Prefecture--A large crane toppled in strong winds at the Takahama nuclear power plant here Jan. 20, causing some damage to the roofs of two buildings but no injuries.

Plant operator Kansai Electric Power Co. reported the incident before dawn Jan. 21 and said no change had been detected in radiation levels in surrounding areas.

The 113-meter tall crane used for construction work collapsed around 9:50 p.m. Nobody was working in the vicinity at the time. The plant's operations have been suspended.

The mangled wreckage lies on an auxiliary building for the aging No. 2 reactor and another building used to store spent nuclear fuel. The fuel rods were not disturbed, Kansai Electric said.

Winds gusting at 50.4 to 54 kph were raging at the time, and a warning had been issued in Fukui Prefecture.

In June last year, the Nuclear Regulation Authority approved the operation of the plant's No. 1 and No. 2 reactors beyond the basic limit of 40 years for another 20 years, the first time it had done so.

Kansai Electric plans to install dome-shaped concrete roofs on the upper part of the reactors' containment vessels as a safety step to fulfill the requirements for the extension.

To prepare for the full-fledged start of the installment work in February, the utility set up four big cranes in December.