Radioactive vapour to be released from Japanese nuclear station

Japanese authorities will release slightly radioactive vapour to ease pressure at nuclear reactor whose cooling system failed.

The failure occurred after a power outage caused by today's massive earthquake off north-eastern Japan.

Japan's nuclear safety agency said pressure inside one of six boiling water reactors at the Fukushima Daiichi plant had risen to 1.5 times the level considered normal.

The agency said the radioactive element in the vapour that will be released would not affect the environment or human health.