APR: your source for nuclear news and analysis since April 16, 2010

Thursday, March 31, 2011

Radioactive Iodine in groundwater at Fukushima Daiichi

TEPCO survey has revealed radioactive Iodine in the ground water at Fukushima Daiichi site, near the No. 1 plant, at a level ten thousand times the allowed limit.

Some readers of this blog have questioned whether or not this had happened or was likely, and given the closeness of the plant to the sea one would have to imagine the water table to be very high. We now have our answer.

How is it getting there? Well, the obvious choice would be through the trenches or tunnels so often discussed the last few days and known filled with highly contaminated water in one case, and very contaminated in another (No. 2 and No. 1 plants respectively.) One might easily imagine cracking in the concrete of these tunnels and allowance of the materials into the groundwater that way. Of course, the very high level might also indicate that one of the reactors' coolant is getting right into the ground, perhaps below the reactor building. Any of the reactors could be producing this but the likely candidate seems to be No. 2, which has been producing the highest known activity in water volumes found so far on the site. This is highly speculative -- the business of determining at this early moment of detection how this ground water was contaminated -- but readers of this blog already can suspect any number of paths and sources considering the damage known in reactor buildings, the water found in the turbine buildings and the water in the trenches.

2:45 PM Eastern Thursday 3/31


  1. Would it not seem plausible that the tsunami is responsible for the presence of water where they did not expect it?

  2. Certainly.. and that's thought to be the cause at least in No. 1 plant's trench. The problem is that the contaminated water wasn't generated until after the core injection began.