APR: your source for nuclear news and analysis since April 16, 2010

Sunday, March 13, 2011

TEPCO / Fukushima Daiichi Update 5:00 PM Sunday Eastern

The last statement we can see from Tokyo Electric Power Company (TEPCO) is about nine hours old, and indicates essentially no changes in plant status for the seriously affected Fukushima Daiichi No. 1 and No. 3 reactor plants or for the shut down and apparently stable, if not "out of the woods" No. 2.

The general consensus between the owner/operator, the Japanese government, various official and unofficial expert sources and this writer is that core damage is confirmed at Daiichi No. 1 and very likely although to a lesser extent at No. 3.

Both Daiichi No. 1 and No. 3 have been flood injected with seawater and a boric acid solution. This will cool the reactor and "poison" it to stop fissions, and ruins the reactor and internals eventually by corrosion and deposition of impurities. This corrosion in an undamaged reactor would eventually lead to fuel element failure if the cooling effect, or degree, were not high enough, but by the time seawater is injected into a reactor core the situation is already grave.

While a number of media outlets, absent the presence of any new information (either good or bad) have begun their normal panicked assault on nuclear energy to fill the down time, it is important to note that ramifications to nuclear energy programs in any other nation are not directly calculable since the seismic situation (the driving force behind these accidents) is so very different.

What has been missed in the hyperbole is the fact that in the history of nuclear energy this is the first time that two reactor plants have simultaneously experienced accidents at the same site. Of course I should be quick to add that this is perfectly plausible, given the extreme nature of the earthquake (9.0 on the Richter Scale, when the plants were designed roughly against a maximum of 7.9) and the grouping of six reactor plants at one site.

As has been mentioned in previous posts, there are very few sites in the United States that have more than two reactor plants. Some, like Perry in Ohio, look as if they have multiple plants .. in this case, two .. but don't since one unit was cancelled and never fully installed, much less finished.

Getting back to Fukushima Daiichi; the threat of hydrogen buildup at No. 3 plant remains. Actual core status, and even containment status of No. 1 plant is not by any means assured at this time (or if it is, the results are not yet public.) One good sign is that the evacuation has not widened further; winds are promised to still be offshore at least a couple more days. No. 2 plant seems least affected, but it's important to point out that it might only be in a longer-delayed process until it too has to be emergency cooled and thus ruined by seawater and boric acid injection.

This concludes our afternoon catch-up on the situation at Daiichi. However, there will be many more posts to come very shortly containing both news and background information helpful to those wishing to stay informed instead of frightened.

5:10 PM Sunday 3/13

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