Fukushima Daiichi update: Tuesday 5/17

As expected, there are a number of news developments from TEPCO and the Fukushima Daiichi site.

TEPCO has revealed the fact that the isolation condenser cooling system (fitted to the oldest plant, No. 1) was shut down within ten minutes of having been actuated automatically after the earthquake. The shutdown of the system is suspected to have been done manually. TEPCO is investigating to discover if this is actually the case, and if so, why the system was shut down. There is speculation that the operators found its operation suspect or unsatisfactory, or were alarmed by the pressure drop in the system.

The water injection rate at No. 1 plant has been reduced back to six cubic meters per hour. TEPCO is analyzing the results obtained during the period of higher injection rate.

As one might expect, there is wide speculation that the cores at No. 2 and No. 3 plant aren't in any better condition than that at No. 1 plant.

For the second time in a week or so, TEPCO has injected borated water into No. 3 plant. This plant has been using two different simultaneous injection paths for a number of days now to try to drive temperatures back down - one firefighting connection and the normal feed system piping. This is of some interest, since the only reason to inject borated water would be due to a fear that increased fission rate is occurring. Considering that in these plants, from what information we have specifically been able to gain, the control rods would melt BEFORE the fuel would melt, it's possible that TEPCO is thinking the rod material is perhaps more at the bottom of a mixed mass of corium.

Finally (for this post, that is) TEPCO is apparently roughly sticking to its original timeline for site recovery.. with plants stable and cooled in six to nine months. A number of additional areas of concern have been merged into the recovery plan, but the overall time expectations are stated by TEPCO as workable.

We have more information and updates in progress.

2:25 PM Eastern Tuesday 5/17
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