Crane safety measures ignored

January 26, 2017

Proper precautions not taken on toppled crane

https://www3.nhk.or.jp/nhkworld/en/news/20170126_14/

The operator of a nuclear plant on the Sea of Japan where a crane toppled earlier this month had not followed specified precautions to prevent the accident.

The crane, which is over 110 meters long, collapsed at the Takahama nuclear power plant in Fukui Prefecture on Friday, January 20th. It fell onto a building housing nuclear fuel and damaged part of its roof.

The operator, Kansai Electric Power Company, believes strong winds were to blame. Officials told media the next day they had taken precautions before the incident.

They explained that the tip of the crane's boom--which reached about 100 meters in height--was secured by wire to a 5-ton weight placed on the ground.

They said the measure was intended to protect the crane against winds of up to about 150 kilometers per hour.

Local weather officials on Friday morning had warned of winds in the area reaching a maximum momentary wind speed of 126 kilometers per hour later in the night.

According to the crane manufacturer's manual, the crane's back should be placed windward in the event wind speed is expected to top 36 kilometers per hour.
The manual also says the boom of the crane should be lowered to the ground when winds of more than 108 kilometers per hour are likely.

Neither of these measures had been taken before the crane toppled.

Kansai Electric officials say they are looking into whether the measures they took were appropriate and are also checking for any damages and corrosion on the crane.

The crane was being used for construction work on the number 2 reactor as part of safety measures required for extending operation of the aged reactor.