(UPDATE) TEPCO now says it may be part rainwater, part leak from CV. See my latest post.
and 30.7 degrees Celsius from 40 meters above.
Infrared thermography seems to show an odd-shaped heat source, possibly partially covered by something else.
TEPCO, who had finally taken infrared thermography on July 20 at the order of Nuclear Regulatory Authority but had done so on a wrong (sunny) day, re-did it in the early morning of July 24 with the similar condition as the day when the steam was first observed on July 18.
From TEPCO's Photos and Videos Library (English), 7/24/2013:
- Measurement date: 4:40 AM - 6:04 AM on July 24, 2013
- Weather condition as of 5:30 AM: Air temperature 18.6°C, humidity 91.1%, wind speed 1.3m/s, wind direction west-southwest
- Measurement height: 5 - 40m above the operating floor of the Reactor Building
- Measurement method:
An infrared camera, which was in continuous automatic shooting mode, was suspended by a
crane at the upper part of the Reactor Building, and it photographed at varying height.
Data was checked after the infrared camera was collected
Steam location, from 5 meters above: