Mitsubishi Heavy Industries has started work on fitting a storage system to capture radioactive sludge at the Fukushima nuclear power plant in Japan.

The plant, which was crippled during an earthquake and tsunami in March this year, is in the process of being decontaminated by its operator, Tokyo Electric Power Co (TEPCO).

Part of this process involves cooling the reactors with water, which in turn produces a slurry-like sludge containing radioactive material.

It is this sludge that the MHI system will capture and store in eight iron tanks surrounded by one meter thick concrete walls.

The 13.5m-long, 3.2m-diameter cylindrical tanks will each hold up to 90 cubic meters of sludge and will be horizontally installed at Fukushima.