Workers at the Fukushima Daiichi nuclear power plant have finished building a temporary steel frame around the damaged unit 1 that will hold a cloth cover.

Frame completed for Damaged Fukushima Daiichi unit 1 reactor cover

Frame completed for Damaged Fukushima Daiichi unit 1 reactor cover

The cover will reduce radioactive exposure to the air, and shelter the unit from rain, reducing the chances of contaminating site groundwater. The frame is unusual because it has been designed to be assembled by a large crawler crane without the help of external riggers.

At unit 3, cranes will also be used to remove rubble from the top of the reactor building to reduce radioactive emissions and improve the site. At unit 3, grab work from a large crawler crane and two excavators sitting on tall gantries will all be remote-controlled because of the relatively high radioactive dose.

At unit 4, heavy machinery will be used to spray the top of the building with an adhesive resin-based compound to reduce the risk of radioactive dust being scattered in the wind. This machinery will be manned, because radiation levels are lower.