TEPCO-Latest Fukushima Details
This TEPCO document has some amazing details.
http://www.tepco.co.jp/en/press/corp-com/release/betu12_e/images/120214e3.pdf
One interesting part starts on page 3, January 29 when it got cold and [I assume radioactive]water leaks started to appear.
- On January 29, we conduct a patrol under the series of water leakage which seems to be occurred by the freeze. At 10:55 pm on the same day, a freeze of Filtrate water was found around the header valve of the circulating cooling equipment the spent fuel pool. We have been conducting water passing in order to prevent freezing around the area. Also we established a floodlight and warmed the area to protect the facility, we confirmed water passing trough the area in the morning patrol which was started at 6:25 am on January 30.
The current R2 temperature sensor(s) saga started on Jan 14 when the CRD housing sensor "broke"
CRD Housing temperature graph is below). This was around the time (page 17) when TEPCO was adjusting the core spray system, with it being turned off/on Jan 25. Then on Feb 2 the other sensor "broke".
My fear is that something fell over when they turned the water back on.
CRD Housing sensor graph.
http://www.tepco.co.jp/en/nu/fukushima-np/f1/images/12021512_temp_data_2u-e.pdf