OKUMA, Japan, March 11, (AP): The Fukushima Daiichi nuclear power plant's radiation levels have significantly dropped since the cataclysmic meltdown 14 years ago Tuesday. Workers walk around in many areas wearing only surgical masks and regular clothes. It's a different story for those who enter the reactor buildings, including the three damaged in the 2011 earthquake and tsunami.

They must use maximum protection - full facemasks with filters, multi-layered gloves and socks, shoe covers, hooded hazmat coveralls and a waterproof jacket, and a helmet. As workers remove melted fuel debris from the reactors in a monumental nuclear cleanup effort that could take more than a century, they are facing both huge amounts of psychological stress and dangerous levels of radiation.

The Associated Press, which recently visited the plant for a tour and interviews, takes a closer look. A remote-controlled extendable robot with a tong had several mishaps including equipment failures before returning in November with a tiny piece of melted fuel from inside the damaged No. 2 reactor. That first successful test run is a crucial step in what will be a daunting, decades-long decommissioning that must deal with at least 880 tons of melted nuclear fuel that has mixed with broken parts of internal structures and other debris inside the three ruined reactors.

Akira Ono, chief decommissioning officer at the Tokyo Electric Power Company Holdings, which manages the plant, says even the tiny sample gives officials a lot of information about the melted fuel. More samples are needed, however, to make the work smoother when bigger efforts to remove the debris begin in the 2030s.

A second sample-retrieval mission at the No. 2 reactor is expected in coming weeks. Operators hope to send the extendable robot farther into the reactor to take samples closer to the center, where overheated nuclear fuel fell from the core, utility spokesperson Masakatsu Takata said. He pointed out the target area as he stood inside the inner structure of the No. 5 reactor, which is one of two reactors that survived the tsunami. It has an identical design as No. 2. Radiation levels are still dangerously high inside the No. 2 reactor building, where the melted fuel debris is behind a thick concrete containment wall. Earlier decontamination work reduced those radiation levels to a fraction of what they used to be.