On October 8, TEPCO completed filling the Unit No. 7 reactor with
water. On 0:00p.m of the same date, our shift operator found that
there was water inside a level gauge connected to the well liner.

All drain water from the well liners* is designed to be collected
in the level gauge. Today, we started monitoring the water level
trend of the level gauge and analyzing the radioactivity of the 
water.

As a result, we detected extremely small amount of radioactive
materials (antimony 124, etc). Due to the detected radioactivity,
we estimated that a portion of water originating from filling the
upper reactor had flowed in through the liner into the level gauge.

Inflow of water into the level gauge (500cc/ hour) is still
continuing. After moving the fuel assemblies, inspection of well
liners as well as the reactor core and the bottom of the reactor
will be implemented.

*Well liner: Stainless steel liners which are put inside the space
of the reactor well, the spent fuel pool, and the steam dryer and
separator storage pool for inspection.