Update: March 20, March 19, March 18
The Japanese nuclear crisis is still touch and go as the spent fuel rod storage ponds now appear to be the largest concern, not the reactors themselves. (click on image to enlarge, source here)
Tokyo radiation levels are still relatively low at a 0.15 uSv rate. A Radiation reading at the nuclear site's main gate late Wednesday afternoon was 1530 uSv (about a half-year's worth of natural backround radiation).
Note: 1,530 microsieverts (uSv) = 153.0 millirems (mrem) = 0.153 rems = 1.53 millisieverts (mSv)
Nuclear plant deaths, missing workers, injuries and contamination as of March 17: (click on image to enlarge, source here)
An excellent March 17 update of pertinent nuclear plant happenings can be found here.
Here are some of the relevant facts concerning Japan's nuclear tsunami crisis:
1. The 40-year old Fukushima nuclear plants were struck by a 9.0 magnitude earthquake that was 5 times more powerful than what these nuclear plants were designed to survive.
2. When the earthquake struck, the nuclear plants did as designed and automatically shut down the nuclear fission process.
3. An hour later, a 33-foot tsunami wave struck the nuclear facility. The reactors and containment buildings survived, but the backup diesel generators were washed away by the tsunami wave.
4. The site's battery power backup system survived both the earthquake and tsunami but was only able to provide power to the reactors' coolant system for a limited time period.
5. The mobile power generators brought to the nuclear crisis scene were unable to provide the necessary power to run the the reactors' coolant systems, which caused heat and pressure to build, even with the nuclear fission process stopped.
6. The loss of proper cooling led to a hydrogen gas buildup resulting in several explosions at both reactor and fuel storage locations.
7. Radioactive materials were released into the atmosphere from the explosions and also the purposeful venting of gases to reduce the likelihood of further explosions.
8.The total released radiation has been relatively minor and not at the levels that will cause health problems for the general populace.
9. Despite all of the above 8 points, a Chernoybl-style nuclear incident causing extreme environmental damage is highly unlikely.
10. Actual physical/human damage to Japan from earthquake: severe; Actual physical/human damage to Japan from tsunami: extremely severe; Actual damage to Japan from nuclear meltdown/radiation: almost non-existent so far.
The nuclear crisis in Japan is not over but it does appears to be creeping towards a manageable level of control, which is a testament to the overall safety of nuclear energy, even if it involves a 40-year old plant design with known disaster deficiencies (eg, placing diesel generators in direct harm's way of tsunami waves, placing spent fuel rod storage in same building as reactor, etc.).
March 16 posting here.