Because of the finding of the puddle containing radioactive materials in 
the trench between the main process building and the miscellaneous solid 
waste volume reduction treatment building (high temperature incinerator 
building), we started inspection of puddles in the trenches etc. at the 
power station on January 11, 2012.
                                (Previously announced on January 11, 2012)

In the inspection conducted today, a member of Tepco discovered puddles in 
the Unit 3 transformer cable duct for activation and the Unit 1 chemical 
tank connecting duct. As a result of nuclide analysis of the water, it was 
found out that the water contains relatively highly-concentrated 
radioactive materials in the transformer cable duct for the activation of 
the Unit 3.

<Confirmed concentration of radioactive materials>
 ·I-131:below measurable limit
 ·Cs-134:4.9x101Bq/cm3 
 ·Cs-137:6.9x101Bq/cm3 
 (Total of the major three nuclides reaches 100Bq/cm3)

We presume that the accumulated water in the building is not likely to have 
flown into the cable duct since the water level (surface) of the 
accumulated water in the building is higher than that of the accumulated 
water in the Unit 3 transformer cable duct for activation. 

○Attachment 
 Inspection Status of Trench etc. at Fukushima Daiichi Nuclear Power Station 
                         (Preliminary Result, January 12, 2012) (PDF 257KB)