BBC: Japan's nuclear watchdog has said the crippled Fukushima nuclear plant is facing a new "emergency" caused by a build-up of radioactive groundwater.
A barrier built to contain the water could be breached in three weeks, the Nuclear Regulatory Authority warned.
This meant the amount of contaminated water seeping into the Pacific Ocean could accelerate rapidly, it said.
There has been spate of water leaks and power failures at the plant, devastated by the 2011 earthquake and tsunami.
Its...