It will take six months to a year to analyze a tiny sample of radioactive debris retrieved by a robot from Tokyo Electric Power Company Holdings' crippled Fukushima No. 1 nuclear plant, its operator said Thursday. The analysis could shed light on radioactivity levels and the chemical structure of the fuel debris -- a key part of preparation for the decadeslong decommissioning process. Around 880 tons of hazardous material remain at the Fukushima plant, more than 13 years after a tsunami caused by an earthquake triggered one of the world's worst nuclear incidents. Last week, the sample, weighing just below 0.7 gram -- equivalent to about one raisin -- was delivered to a research lab near Tokyo for analysis. It had been removed from a reactor by an extendible robotic device in a tricky operation suspended several times by technical problems.