A year after the Fukushima No. 1 nuclear power plant was ravaged by an earthquake and tsunami, the challenge of keeping the facility under control continues, and does so without a clear picture of what is actually happening inside the three crippled reactors.

The country is also groping for ways to clean the vast radiation-contaminated areas outside the plant, located about 220 km northeast of Tokyo, but securing places to store even topsoil after removal is not easy, given the opposition of communities beyond the fallout areas.

The nuclear crisis started shortly after the March 11 natural disasters led to the loss of nearly all of Fukushima No. 1's power sources, and consequently the ability to cool the reactors and spent fuel pools.