Fukushima Daiichi No. 1: Core melt / exit of pressure vessel specualted by TEPCO, NISA

Saturday, May 14, 2011

Fukushima Daiichi No. 1: Core melt / exit of pressure vessel specualted by TEPCO, NISA

There are a number of very serious reports on the various Japanese news media at this moment; we will report these and make commentary in a sober fashion.

NHK is carrying the report, from TEPCO apparently, that there is a hole in the bottom head of the pressure vessel at No. 1 plant. This appears to be in addition to the previously reported piping damage, although another report does indicate water leakage from piping connected to the primary plant occurring in the turbine building. JAIF's now-irregular status reports do now indicate probable damage and leakage in terms of the reactor pressure vessel and also the primary containment at the No. 1 reactor plant.

Link to the most recent JAIF status report.

Combining this estimation... the presence of a hole in the lower reactor pressure vessel head... with the previous information gleaned sporadically over time may in fact indicate a corium/concrete reaction has, or had, occurred. The source and routing of the large amount of hydrogen which destroyed the reactor building has not been adequately explained up until this point; partial corium exit from the reactor vessel into the dry well and the corium/concrete reaction that would result could help explain the violent destruction of the reactor building.