Hundreds of water tanks are to be sent to Japan’s Fukushima nuclear plant to hold thousands of tons of water that was contaminated in the effort to keep reactors cool, according to operators TEPCO.
The company released footage showing highly radioactive steam rising over a vent opening at one of the reactors at the plant.
The vapour carries the highest ever radiation levels recorded inside the plant since March.
Workers have started installing equipment supplied by French reactor maker Areva to clean the nearly 90,000 tons of harmful water. It will start operating from mid-June.
Managing the growing pools of radioactive water is a major challenge for TEPCO.
In early April the company dumped about 10,000 tonnes of water with low-level radioactivity into the ocean prompting concerns from neighbours China and South Korea.