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

Tuesday, March 29, 2011

Tuesday morning (Eastern) update

There are not a lot of new details coming out of Fukushima Daiichi, NISA or TEPCO today... work is continuing on just a few very important areas right now. Here's what we can deliver..

Apparently the reduction of injection volume to No. 1 plant eventually led to a temperature rise higher than when the reactor is normally operating, according to TEPCO representatives... the water injection has been increased again.

The plan for the turbine building 'unauthorized' water in all three plants is to get it into the condenser hotwells, which reportedly can hold 1600 tons of water. In two plants, though, the hotwells are already full. The plan for these is to get the water presently in condensate storage tanks pumped into the suppression pool surge tanks, and then pump the hotwells to the condensate storage tanks. This frees up the condenser hotwells for the large water volumes now found in the turbine building basements.

No other real plans of note have been released; obviously the major focii of today at Fukushima Daiichi have been dewatering the turbine buildings and monitoring the trenches while at the same time ensuring proper core cooling. TEPCO needs to tackle this displaced (and in some locations contaminated) water situation as soon as possible, and as far as we know now, hasn't released a plan for dewatering the trenches outdoors.

In an unrelated location, Chubu Electric Power has run a fantastic drill sequence at its Hamaoka nuclear station, and press were allowed. The company ran an SBO sequence in its control room simulator, showing what occurs and the operator responses. After this, outside, the company staged practice drills of bringing in fire trucks to supply emergency cooling water and portable diesel generator equipment for emergency power. The company said this is part of its response to knowledge of the Fukushima Daiichi accident, and it has also announced plans for a roughly 36 foot high protective wall around the Hamaoka plant. Chubu is getting it right -- respond to the accident scenario quickly and show the public that you are doing everything you can figure out to prevent this happening again.

9:00 AM Eastern Tuesday 3/29


  1. Is that a 36 foot high or deep wall? If it is a 36 foot high wall, what does that protect against?

    Looks like most of the hydrogen explosion danger was stuff in the air, not debris flying onto plant surroundings.

    Thanks for the information.

  2. That wall is to protect the Hamaoka station from tsunami.

  3. Ah, thanks. I missed info on how the tsunami knocked out the backup systems, how high, onto further reading.