OT: putting a little perspective on this Fukushima report
After much international pressure on the Japanese government they finally recently forced TEPCO (Tokyo Electric Power Co.) to begin massive groundwater pumping from under the power plant complex in order to try to create a negative well of ground-water gradient to get water flowing into the the well instead of passing by and into the ocean.
There is a long history that whatever has been released publicly as a measure on the extent of radiation release has turned out to be vastly understated. They are presently saying 300 tons per day has been escaping into the ocean, likely because that is the pump rate they have managed to get to in order to create the initial ground-water gradient.
300 tons is a cube 7 yards on a side, or the amount of water that will cover a property 100 foot by 100 foot to a depth of 1 foot.
Now, notice that the new leak reported from a 1000 ton holding tank resulted in contamination measured at 100 millisieverts per hour. I have not seen public release of the radiation level in the stored water, or of the water being pumped out to create the initial groundwater gradient, but I have seen reports that the ability to store water is continuously challenged with more "make-shift" capacity being added all the time due the inability to scrub the radiation from the water such that all the water that has been continuously pumped into the four reactor remains and the four spent fuel pools is used once instead of being recycled (there are reports of some initial success allowing some hope of reuse). All of this is sitting in ponds on-site, much exposed to the atmosphere, and all unshielded.
OK so a 100 x 100 area 1 foot deep. If it is at the 100 millisieverts per hour level of contamination, in order to bring that level down to the maximum level allowed of 100 millisieverts per 5 years for workers at the clean-up then that would have to be diluted by the number of hours in 5 years, or 43,800.
So if that is the radiation level of water escaping per day (and this has been going on over the past 2.5 years) into the ocean, once it is diluted to merely the allowed maximum level for workers at the plant one day's escaped water would be a layer of water 1 foot deep and 20,928 feet on a side.
That is roughly a 4 mile by 4 mile square 1 foot deep to which a person could be continuously exposed and just reach the maximum annual exposure allowed to workers at the Fukushima plant.
That is the publicly acknowledged PER DAY rate of release into the ocean. It has been going on for around 900 days. AND shortly after the Fukushima disaster the maximum exposure allowed for workers at the cleanup was increased by the Japanese government from, if I am recalling correctly 5 to 100.
If one factors that in, it is equivalent to the top foot of the ocean being contaminated to a degree that would cause the previous maximum exposure rate over an area of the ocean 16 miles by 20 mile PER DAY.
This is only the publicly admitted ground-water rate of contamination the ocean. The out-gas contamination to the atmosphere from the four exposed reactor core remains, from the exposed fuel storage pools, and the make-shift on-site water storage, plus that of radiation carried in steam and evaporates from these is not included.
PS. Areas in the steam stacks at the plant have been measured with contamination levels that pinned the detectors at their maximmum of 1 sievert per second, that is 600 times the level in the ground from the tank leak
