January 13, 2015
Cs-134/137 and all β nuclides (including Sr-90) density showed the rapid increase in groundwater, according to Tepco.
The sample was taken in the seaside of Reactor 2. Sampling date was 1/12/2015.
Compared to the previous measurement of 1/8/2015, Cs-134/137 density rose up by 57 times, all β nuclides density also rose up by 57 times.
This is the highest reading measured from this boring. Tepco hasn’t identified the reason. This boring is located outside of the underground wall to stop contaminated groundwater flowing to the sea.
TEPCO groundwater plume mapping assumed the contaminated water released from the unit 1 turbine building would eventually reach this area.
TEPCO said within recent weeks that the portions of this trench that were not yet filled in with concrete were seeing contaminated water re-fill the trench as they pumped it out and that both ends of the trench seem to rise and fall with each other.
The concreting of the unit 2 trench that had been full of highly contaminated water since 2011 has caused leaking contaminated water to divert over to this area.
Theoretically, it is natural to assume the high level of contamination is flowing to the sea without anything to stop.
Source: Fukushima Diary