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

Thursday, March 31, 2011

Thursday morning update @ Fukushima Daiichi

Some new details...

Reported elsewhere and skipped here is the attempt to contain or seal contaminants at the site by spraying them with a solution that will essentially "paint" dust and particles in place. This will prevent the material from becoming airborne. This has been done before and worked reasonably well in preventing spread of contamination (although back when it was done around SL-1 it was done with asphalt if I recall correctly.) This time a sprayable resin will be tried. Remember though that this does nothing to neutralize the radioactivity of the substances; it simply changes the nature of the contamination from loose surface contamination essentially to fixed surface contamination... so in order to complete site cleanup (25 years down the road or so, possibly) you still have to remove it.

Water level in the tunnel or "trench" at No. 1 plant is down around a meter, and work continues at all plants do dewater all spaces that are normally dry. There is a reading of 400 mSv/hr at the water surface in No. 3 plant.. making it not as hot radiologically as No. 2 but significant nevertheless.

Looking at the latest figures, the feedwater nozzle temperature on No. 1 unit is down about 30C since the last time I reported it, which is encouraging. Temperatures at No. 2 have been coming up a bit .. and the lower reactor vessel head temperature indication has failed. No. 3 appears stable.

There has been some trouble cooling the spent fuel pool at No. 2 plant. Apparently the temporary fresh water pump failed (cause not known) and a fire truck was brought in and hooked up. However, the hose failed and water supply was again cut off to the spent fuel pool. If it restarted yet, we don't have that data. Last spent fuel pool temperature for No. 2 plant was 48C. (Actually, the indicators are failed at the other two plants for this parameter.)


These are the new details and developments. The serious focus on dewatering continues.

6:05 AM Eastern Thursday 3/31

No comments:

Post a Comment