Saturday morning update

Unfortunately, your author suddenly became quite ill yesterday and hasn't been on his feet since. However, he's back vertical temporarily and here are the most important updates since the last post.

TEPCO continues to try to stop any and all leakage of contaminated water into the ocean by the use of further plates outside the plant seawater inlet screens, and the use of zeolite in large bags to trap radioactive particles in the water. While the vast majority of the coverage on Japanese television stations and other media there is focusing now on the problems being suffered by the evacuees, there continues to be a major focus outside Japan on the effect that spread of radioactive contamination will have in the Pacific fishing business. This cannot be denied, but it shows the focus of those not living in the disaster area.

The dewatering problem at the Fukushima Daiichi plants continues to slowly get more ponderous as water being deposited into the very complicated universe of buildings, pipe tunnel connections, drain pipes and drain sumps, various cracks in the outside and the substrate material continues to grow in volume; yet, it is necessary to clear the turbine buildings of this water in order to stop the supply. Apparently new reviews by NISA and TEPCO indicate that only half the theoretical maximum volume in the plant main condensers can now be used for water storage, since with the weight involved at a higher level they're not guaranteed safe in another earthquake. This loses TEPCO about 3750 tons of water storage capacity it would like to have used.

Further work continues on-site but not right in the plants to clear the area of rubble using the aforementioned remotely-controlled construction equipment, and more spraying of polymer to fix the radioactive debris and dust to the ground has been accomplished.

Electrical distribution gear for the core supply pumps at Fukushima Daiichi have been moved up to a nearby hill, as part of the overall action (being taken at every nuclear plant in Japan, to some extent, too) to prepare for any further earthquakes and tsunamis.

Temperatures at No. 1 plant continue to lower, while pressures remain steady. None of the plants is rising in temperature or pressure at this time.

The most interesting news of the day is the still developing story that TEPCO has ordered a large number of special heat exchangers, planned for a new external cooling system that it will construct for each reactor plant. This is a novel approach, and probably the best idea TEPCO has had yet. According to the Kyodo story, TEPCO will use several heat exchangers for each plant, and will connect them to the existing external emergency connections that it's been using prior to this for core injection. Apparently TEPCO will use electric pumps, and two core connections to establish recirculating cooling flow and then use hoses to bring in and return seawater, if we understand the plan correctly. No timeline is given on this plan -- but given the mounting complications of the water in the buildings and in the ground, I would have to say that this plan should be given top priority.

9:20 AM Eastern Saturday 4/16
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