Update #18, June 14, 2011
Problems at Unit 4.
Three months after the explosions, TEPCO entered Unit 4 for the first time and finds the pipes are too severely damaged to be used in the planned water circulation cooling system. Back to the drawing board. The whole idea of the circulating water systems was to reduce the amount of radioactive contaminated water flowing into the basements, tunnels and trenches at the plant from the spraying/pumping operations.
The water in the spent fuel pool (SFP) is at 85°C (185°F). For reference the SPF temperature at Unit 2 is 32°C and at Unit 3 is 62°C. So spraying must continue and will continue to create contaminated water.
Pictures of the vast damage at Unit 4:
http://www.tepco.co.jp/en/press/corp-com/release/index-e.html
TEPCO forced to review reactor 4 cooling plan
http://www3.nhk.or.jp/daily/english/12_02.html
Nelle's comments: Still waiting to see if this filtering system will remove radioactivity at the 99.9% humidity levels inside the building. If it doesn't, will they still open the doors in an attempt to lower the humidity despite the radioactivity release this will precipitate?
No.2 reactor air filter starts running
http://www3.nhk.or.jp/daily/english/11_13.html
Test-run to be delayed at Fukushima
http://www3.nhk.or.jp/daily/english/13_12.html
Nelle's Comments: I don't understand this sea water operation at all. How can they possibly expect to reduce the level of radioactivity in the ocean by this activity? Especially considering the capacity of the equipment. Furthermore, I read on a physics forum blog that the reason the equipment (basically a big tank full of zeolite) is only removing 20%-30% of the cesium is due to the high levels of oil in the sea water. Which means they need to filter out the oil prior to this treatment.
TEPCO begins operating seawater treatment system
Tokyo Electric Power Company, or TEPCO, has begun work to reduce the level of radioactivity in seawater near the damaged Fukushima Daiichi nuclear power plant.
The company began full-fledged operation of 2 filtering devices on Monday after a series of test-runs.
The devices are installed near the water intakes of the Number 2 and Number 3 reactors, where high radiation levels have been detected.
The devices are designed to first pump up seawater and then absorb radioactive cesium using the mineral zeolite. The water is returned to the sea as the final step.
TEPCO says each device is capable of treating up to 30 tons of seawater per hour. Tests showed the machines reduced cesium levels by 20 to 30 percent. The company says it will find ways to increase filtering capability.
The devices have been installed inside submerged fences set up near the intakes. The fences were installed in April to prevent radioactive water from spreading to the sea. However, radiation levels higher than government safety standards are being detected outside the fences.
Monday, June 13, 2011 17:11 +0900 (JST)
http://www3.nhk.or.jp/daily/english/13_21.html
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The Watershed Sentinel is proud to share Nelle Maxey's Fukushima Updates prepared for the BC environmental community.
Every day, Nelle pours over the media and other reports of the status of the reactors at Fukushima, comparing figures and trying to make sense out of the conflicting reports.