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Monday, May 23, 2011

Fukushima Daiichi update: Monday, 5/23

As has become the case in the last few weeks, with the plant conditions stabilized, the train of press releases and other news items from Fukushima Daiichi grinds to a halt over the weekend, and then starts up to full speed again on Monday. Of course, work at the site, at TEPCO HQ for planning, and at Japan's NISA and other offices doesn't stop over the weekend, meaning that there is usually a lot of catching up to do on Mondays. This Monday is no exception.

First, keeping up with a trend we've been following the last several days on this site, it seems TEPCO is continuing to back off injection rate at No. 3 plant. Today we have the news that TEPCO reduced the injection rate through the firefighting line from 6 to 5 cubic meters per hour at 11:31 AM on the 23rd, and then further reduced it to 4 cubic meters per hour at 2:08 PM. Thus, the total injection rate is the combined 4 from the firefighting line and the 12 through the feed line giving 16 cubic meters per hour... still more than the 6 and 7 cubic meters per hour at No. 1 and No. 2 plants, respectively. Temperatures at last available reading were still stable on No. 3 plant.

Some other points of news from the site, briefly:

-TEPCO has begun performing air sampling around and above the reactor buildings, to check for airborne release. This will be reported to NISA.

-TEPCO has launched its effort to gusset, or support, the spent fuel pool area of the No. 4 reactor building. Shielding has been brought in to reduce exposure to the workers who will begin installing steel columns to hold up the pool, whose floor will be reinforced (from underneath, not from inside) with a layer of concrete.

-TEPCO is expected to submit a report to the Japanese Government today which will apparently assert clearly that there was NO damage to the reactor plants as a result of the Great East Japan Earthquake. Plant data charts and tapes, and debriefing of employees are TEPCO's evidence. The damage sequence began ... as this blog has asserted time and again since being among the very earliest to do so ... when the tsunami hit and triggered an essentially unrecoverable SBO accident scenario. We will have details of this report here when it comes out.

Similarly there are reported to be a number of new photos and a video which TEPCO will release at some point, and those will either appear here or else on the Atomic Power Review YouTube channel.

-TEPCO has decided that reducing the temperature of the spent fuel pool in the No. 2 plant will drastically lower the ambient humidity in the reactor building... and so will install a new heat exchanger for the spent fuel pool's cooling as soon as possible. Reduction in the humidity will make work in the building possible by people rather than just by remote controlled robots.

Finally, for this post... Many people have commented and e-mailed about the report that TEPCO operators shut off the isolation condenser cooling system that was in use at No. 1 plant after the loss of power, when it was the primary heat removal system in such a situation. I have not commented on this as of yet... as have I also not commented on NHK News saying that it has a "copy of the Fukushima Daiichi Operating Manual" and can prove improper operation... because there simply are not enough solid details available yet. On the No. 1 plant cooling issue, supposedly the operators shut the system off and then it took several hours to restore any sort of core cooling. On the NHK-asserted improper plant ops issue, supposedly the operators didn't vent the containment anywhere near early enough and violated operating rules during the casualty by not doing so.

Both of these are serious accusations. Apparently TEPCO is looking seriously into the first, while it has not commented on the second. Frankly, I don't know what documents NHK has in its possession... and if someone unfamiliar is reading any sort of actual operations literature it's sure to be misinterpreted.

It is not my desire to "blow off" accusations, but in both cases we simply do not have any solid information from TEPCO on validity or effect. Until we do there's little point in analyzing such things and playing the blame game. If it comes out that TEPCO operators were incompetent, I'll certainly be printing that here because first and foremost in importance for the long-term is to understand all of the contributing actions and events that led us to the Fukushima Daiichi Accident as it stands right now. Operator error almost always figures into accidents; the question here is how, and when.... as long as there is more proven than an "if."

2:45 PM Eastern Monday 5/23
ATOMIC POWER REVIEW

2 comments:

  1. A word of caution: NHK is essentially a government friendly state-run broadcaster. In all these years I have never seen NHK having some sort of "scoop" or controversial accusation, especially that may hurt the government's interests. Perhaps it is in the government's interest to shift blame to Tepco right now, who knows. Just take whatever they say and how they say it with great caution. Other channels might be a little better.

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  2. @ashen: I look at a horde of Japanese media, but frankly the best data comes from the Japanese government and TEPCO itself. NHK has consistently been first with the big stories, so it's kind of surprising that the latest (in another post) came out first on Kyodo.

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