CNN - March 21, 2010:
The disaster has killed more than 8,600 people and left more than 13,000 missing, many of them killed as a wall of water rushed following the quake. Ever since, authorities have been work to avert further crisis -- and prevent more deaths -- at the Fukushima Daiichi plant, some 240 kilometers (150 miles) north of Tokyo.
Those efforts include a move to possibly encase one or more of the reactors in concrete, a last-ditch effort similar to what was done after the 1986 meltdown at the Chernobyl nuclear plant in the former Soviet Union -- considered the worst nuclear disaster at a plant.
On Monday, an official with Japan's nuclear and industrial safety agency told reporters that tests are expected to be conducted in the afternoon on how to use what he called a "concrete pump engine."
The engine would pump a mix of mortar and water into the reactor's spent nuclear fuel pool and containment vessel, the official said. The pool contains nuclear fuel rods that could give off radioactive material, if exposed and overheated, while the containment vessel is a steel and concrete shell that insulates radioactive material inside.