[…]
Cleaning up the plant’s three reactors that had at least partial meltdowns after the earthquake and tsunami is a monumental task expected to take three to four decades. Taking out the stored fuel rods is only a preliminary step and just removing the ones in Unit 3 is expected to take a year.
Still ahead is the uncharted challenge of removing an estimated 800 tons of melted fuel and debris inside the cracked containment chambers — six times that of the 1979 Three Mile Island accident.
The area in and outside of Unit 3 is part construction site and part disaster zone still requiring protection from radiation. A makeshift elevator, then a wind-swept outdoor staircase, takes visitors to the operating floor, more than 30 meters (100 feet) above ground.
[…]
Radioactivity on the Unit 3 operating floor has fallen to a level that allows workers in hazmat suits and filter-masks to stay up to two hours at a time, though most work still needs to be done remotely.
The segments of the new cover were pre-assembled and are being installed one by one by remote-controlled cranes. With two pieces left, the plant operator says the cover will be completed in February.
Removing the fuel rods in Unit 3 will be done with a fuel-handling crane. It will move the rods out of their storage racks and pack them in a protective canister underwater. A second Toshiba crane, a 10-meter (33-foot) -high yellow structure across the operating floor, will lift the canister out of the pool and load it onto a vehicle for transport to another storage pool at the plant.
[…]
The 1,573 sets of fuel rods stored in spent fuel pools at the three reactors are considered among the highest risks in the event of another major earthquake. Loss of water from sloshing, structural damage or a power outage could cause meltdowns and massive radiation leaks because the pools are uncovered.
[…]
Despite scarce data from inside the reactors, the roadmap says the methods for melted fuel removal are to be finalized in 2019, with actual retrieval at one of the three reactors in 2021. Hirose says it is premature to say whether Unit 3 will be the first.
Read more at Worst-hit reactor at Fukushima may be easiest to clean up
