On March 8 2017, SimplyInfo.Org published its 6th anniversary report on the nuclear disaster at Fukushima. I offer it here for those interested in keeping up with what was always going to be a 'forever' disaster -
Fukushima Daiichi 6th Anniversary Report
For those whose memories are dim, the disaster arose as an unfortunate result of the 'Great Tohoku Earthquake' and subsequent tsunami of March 11, 2011 that caused the deaths of thousands of Japanese citizens. The 9.0 level quake knocked out power and power infrastructure in northern Japan and caused the emergency shut-down of the entire Japanese commercial nuclear fleet. Tokyo Electric Power Corporation [TEPCO]'s Daiichi nuclear facility on the coast of Fukushima Prefecture was home to 6 power reactors, 3 of which were operating at the time of the quake. The resulting tidal wave inundated the 4 waterfront plants at the facility and wiped out their emergency diesel generators. All 4 suffered destruction of their reactor plant buildings [a.k.a. "secondary containment"], and the three that were operating suffered total meltdown/melt-throughs (then they exploded).
TEPCO has been less than honest since the beginning about radioactive contamination that has been steadily released into the environment (air and water) for six long years, and continues to be released to this day. Health effects are and will be what they are, various groups and the regional Japanese medical system are monitoring and responding as cancers and other maladies appear.
What's Happening at Daiichi
Removal of spent fuel stored in the destroyed units' jam-packed spent fuel pools [SFPs] when the disaster occurred is a priority project. The #4 SFP was completely emptied of used fuel assemblies by 2015. Unit-4's reactor was not operating at the time of the tsunami, so its core was in the SFP and did not suffer meltdown. Units 1, 2 and 3 still await their turns to be defueled, due to much higher levels of radiation and contamination because their reactors were operating and melted right on down. The 6th year report follows what passes for the TEPCO timetable (as is at present) as far as its order of work to be done. It appears that unit-3 will be the first of the melted units to be defueled — entirely by remote control if possible — then unit-2, and unit 1 some time after that. As of the 6-year mark, TEPCO has been unable to get a good look at the #1 SFP. They have removed the temporary covering over the unit installed shortly after the disaster so they can begin removing collapsed roofing/equipment and assorted explosion debris on the refueling floor. Hopefully without re-contaminating large tracts of farmland as occurred during the debris removal at unit-3.
Another aspect of the mess at Daiichi is the little matter of where what's left of the reactor cores that used to be in the units 1, 2 and 3 reactor vessels ended up. The Great Corium Hunt proceeds in fits and starts depending on what imaging and/or robotic technologies they've got available this month. They have found a relatively small amount of hardened corium drip/splash and melt-debris in odd places, but the bulk of corium from all three reactors - more than 400 metric tons of reactor fuel mixed with assorted other metals and minerals all melted together - is still MIA. TEPCO does remain fairly confident the corium flows are somewhere nearby, they just haven't found 'em yet.
The corium appears to largely be under ground level in the basements or below. The basements are flooded as the water table beneath the facility rose to nearly ground level after the earthquake, and that water beneath the plants is highly contaminated. This water has been "leaking" to the Pacific Ocean steadily since March of 2011, in greater or lesser amounts (measured in tens to hundreds of tons per day). All efforts to keep water from escaping have been futile, though some efforts have been semi-impressive and doubtlessly expensive. At some point, maybe this year, they hope to be able to bring on-line the last section of the "frozen ground wall" they've installed between the plants and the harbor bulkhead some yards away. Perhaps this will cut the flow appreciably.
This mess will be ongoing until long after I'm dead. The SimplyInfo report is quite detailed, with lots of pictures and diagrams and graphs, descriptions of current and planned technologies (including robotics), and offers the latest iteration of TEPCO's hopeful plans through 2020. From the conclusions -
Will the disaster site at Fukushima Daiichi ever be cleaned up? That remains to be seen. The technical challenges are immense. Technology must be invented to deal with the conditions at the plant. Many times it has to be modified or re-evaluated on the fly as new challenges show up. Just giving up is not an appropriate response.
Not appropriate by a long shot, but probably how this unholy mess is finally not-really dealt with.