Japan's nuclear watchdog has criticised the safety checks by plant workers at the Fukushima Dai-ichi plant. The comments come as it emerged hundreds of tonnes of highly radioactive water leaked from the plant into the Pacific Ocean. The leak is the fifth such incident in a year.
Officials said workers apparently overlooked several signs of the leaks - and suggested that the twice-daily patrols recorded were largely just a walk. Water levels inside tanks were not monitored, and the puddle that caused this latest leak was not detected, until it was too late.
Watchdog chairman Shunichi Tanaka said another radioactive leak into the sea is a real fear, and steps must be taken immediately to safeguard the plant.
That's what we fear the most. We must remain alert.
We should assume that what has happened once could happen again, and prepare for more. We are in a situation where there is no time to waste.
More top news
Wet and windy weather will spread in from the west, turning to snow in places, especially later over the hills.
McDonald's in Japan will resume serving large portions of French fries in January after a labour dispute in the US disrupted supply.
More than four in 10 cases of cancer in the UK could be avoided if people made changes to their lifestyle, Cancer Research says.