A crane collapsed Friday night at the Takahama nuclear power station in Fukui Prefecture, damaging a building housing spent fuel, the plant operator said Saturday.

No one was injured in the accident at around 9:50 p.m. near the No. 2 reactor building and nothing fell into the spent fuel pool, according to the operator, Kansai Electric Power Co.

The crane also damaged the roof of an adjacent building.

A wind warning was in effect in the area, and strong winds were blowing at the time, according to the utility.

The 112-meter crane had been used to prepare for safety-enhancement work in which a concrete dome will be placed over the No. 2 reactor building. Work was not being undertaken at the time of accident.

An official apologized for the accident at a news conference at the plant, saying the utility would re-examine the risk of crane accidents amid strong winds and investigate the cause of the incident.

There are 59 fuel assemblies in the pool, including spent ones, according to Kansai Electric.

The No. 2 reactor is one of two aging reactors at the plant, in operation for over 40 years. Safety-enhancement work for the facility is expected for completion in 2020.

In June last year, nuclear regulators approved the utility's plan to extend the operation of the Nos. 1 and 2 reactors beyond the government-mandated 40-year service period. It was the first such approval given under new safety regulation introduced following the 2011 Fukushima nuclear accident.

The plant has two newer reactors. All four reactors are currently offline.