Tiny grain of nuclear fuel pulled by robot from ruined Japanese nuclear reactor

The Fukushima Daiichi nuclear power plant in Okuma, Fukushima prefecture, northern Japan - (ASSOCIATED PRESS)

A robot that has spent months inside the ruins of a nuclear reactor at the tsunami-hit Fukushima Daiichi plant delivered a tiny sample of melted nuclear fuel on Thursday.

The move was described as a step toward beginning the cleanup of hundreds of tons of melted fuel debris.