30 Mars 2012
Journal of Nuclear Science and Technology has a paper by Fumiya Tanabe of Sociotechnical Systems Safety Research Institute published online on March 28, 2012.
Tanabe is the one who said last August that there was a second "meltdown" in Reactor 3 on March 20-21, in which the melted fuel dropped through the Reactor Pressure Vessel onto the floor of the Containment Vessel, releasing a large amount of radioactive materials that caused the spikes in radiation levels in wide areas in Tohoku and Kanto.
In November last year (11/19/2011), he also disclosed his analysis of the Reactor 2 Suppression Chamber, and concluded that it may have been damaged by the earthquake. This paper looks to be that analysis, now peer reviewed and published.
The paper was received on December 9, 2011, accepted final version for publication on January 24, 2012.
So it is possible to disclose the outline of the analysis before submitting the paper to a peer-reviewed magazine, and the magazine has no problem accepting and publishing the paper. (All those researchers in Japan and elsewhere in the world who withheld their data, analysis, research until their papers were published by peer-review magazines, what would you say now?)
From Taylor & Francis Online:
A scenario of large amount of radioactive materials discharge to the air from the Unit 2 reactor in the Fukushima Daiichi NPP accident
Based on an analysis of the measured data with review of calculated results on the core melt accident, a scenario is investigated for large amount of radioactive materials discharge to the air from the Unit 2 reactor. The containment pressure suppression chamber (S/C) should have failed until the noon on 12 March 2011 only by seismic load due to the huge earthquake on 11 March or by combination of seismic deterioration and dynamic load due to steam flowing-in through safety relief valve. Opening of the two safety relief valves (SRVs) at 14 March 21:18 should have resulted in discharge of large amount of radioactive materials through the S/C breach with the measured air dose rate peak value of 3.130E-3Sv/h at 21:37 near the main gate of the site. The containment drywell (D/W) should have failed at 15 March 06:25, at the cable penetration seal due to high temperature caused by the fuel materials heating up on the floor of the D/W, which had flowed out from the reactor pressure vessel. Then large amount of radioactive materials should have been discharged through the D/W breach with the measured air dose rate peak value of 1.193E-2Sv/h at 15 March 9:00.
Is Tanabe saying that venting of Reactor 2 on the night of March 14, 2011, with the Suppression Chamber already broken due to the earthquake, caused a discharge of a large amount of radioactive materials through the Suppression Chamber?
What a tragi-comical sequence. Amateur hours.
If the Reactor 2 Suppression Chamber was already damaged by the earthquake, what about other Reactors?