A tiny grain of nuclear fuel is recovered from devastated Japan…

TOKYO (AP) — A robot that spent months in the ruins of a nuclear reactor at the tsunami-hit Fukushima Daiichi nuclear power plant delivered a tiny sample of melted nuclear fuel Thursday, in what plant officials said was a step toward beginning the cleanup of hundreds of tons melted fuel residue.

The rice-grain-sized sample was placed in a secure container, marking the end of the mission, according to Tokyo Electric Power Company Holdings, which manages the facility. It will be transported to a glove box for size and weight measurements before being sent to external laboratories for detailed analysis in the coming months.

The plant’s manager, Akira Ono, said they would provide key data to plan a decommissioning strategy, develop the necessary technology and robots and learn how the accident unfolded.

Despite numerous investigations in the years since the 2011 disaster that destroyed the power plant and forced thousands of residents to evacuate their homes, much about the site’s highly radioactive interior remains a mystery.

The sample, the first taken from inside a reactor, was significantly less radioactive than expected. Officials had feared it might be too radioactive to test safely even with heavy protective gear and set a cap on how much it could be removed from the reactor. The sample was well below the limit value.

That has led some to question whether the robot took the nuclear fuel it sought from an area where previous probes have found much higher levels of radioactive contamination. However, TEPCO officials insist they believe the sample is molten fuel.

The extendable robot, nicknamed Telesco, first began its mission in August with plans for a two-week round trip after previous missions had been delayed since 2021. However, progress was interrupted twice due to glitches – the first was an assembly error that took almost two weeks to fix, and the second was a camera error.

On Oct. 30, it cut a sample weighing less than 3 grams (0.01 ounces) from the surface of a mound of molten waste fuel lying on the floor of the primary containment vessel of the Unit 2 reactor, TEPCO said.

Three days later, the robot returned to a closed container as workers in full protective gear slowly pulled it out.

On Thursday, the gravel, whose radioactivity earlier this week was well below the upper limit set for its environmental and health safety, was placed in a secure container for removal from the compartment.

During sample return, the melted fuel is removed from the containment container for the first time.

Fukushima Daiichi lost its key cooling systems during an earthquake and tsunami in 2011, leading to meltdowns in its three reactors. An estimated 880 tons of deadly radioactive molten fuel remain inside them.

The government and TEPCO have set a 30- to 40-year goal to complete the cleanup by 2051, which experts say is overly optimistic and should be updated. Some say it would take a century or more.

No concrete plans have been decided for the complete removal of the fuel residues or their final disposal.