6/22/2011 | TEPCO restarts Fukushima Daiichi water treatment but tests show underperformance

TEPCO has continued tested it's radioactive water treatment system at Fukushima Daiichi but discovered that the subsystems were not performing up to expectations. Per the EX-SKF blog expectations were for a 1/1,000,000 reduction in radioactive materials overall after filtering, but only a 1/18,400 decrease was actually achieved. The under-performance was noticed in the Kurion treatment subsystem, as well as the Areva (French) subsystem which both did not perform up to expectations.

The latest estimate for the amount of water pooled at the Fukushima Daiichi complex is estimated at more than 110,000 tons. Per TEPCO spokesman Junichi Matsumoto 1700 tons of water have been treated so far. The processing rate at which TEPCO wants to run the water treatment system is 50 tons/hour. Assuming 24 hour nonstop operation, 1200 tons/day of radioactive water could be theoretically processed at this rate.  Approximately 500 tons a day of water is injected in to Fukushima Daiichi per the JAIF (Japan Atomic Industry Forum, Inc.) Earthquake Report for June 22, 2011.

In order to decrease the rate at which the radioactive water is building up TEPCO has reduced the amount of water being poured in to reactors 1 (-.5 tons/hr), 2 (-.5 tons/hr) and 3 (-1 tons/hour) while carefully monitoring the heat level of the reactors. The #3 reactor did experience a heat rise per TEPCO who are monitoring closely without increasing the water poured in to the reactor. The water flow in the #1 and #2 reactors will be reduced by another -.5 tons/hr.

The right sidebar of the EX-SKF blog shows the number of millimeters left to the top of the water ditches for reactors 2 and 3 if you are interested in imminent overflow.

6/20/2011 | Only a few more days of storage capacity left at Fukushima Daiichi for radioactive water

Date: 6/20/2011
by: Jason Chan

TEPCO is still struggling against time to get their on-site Frankenstein-like radioactive water treatment system up and running. According to NHK World, there are only "a few days" of radioactive water storage capacity left (the NHK article is dated Tuesday, June 21, 2011 05:11 +0900 JST).  It is estimated that more than 100,000 tons of radioactive water is currently pooled at the Fukushima Daiichi complex.  If the radioactive water is not able to be decontaminated at a rate at least equal to the amount of radioactive water produced each day (500 tons/day per JAIF), the overflow would go to the sea.

The ad hoc TEPCO water treatment system has been cobbled together from other systems made by French, American and Japanese companies. Per blogger EX-SKF:

...
To review the whole [radioactive water treatment] process, the water first goes to Toshiba's oil separation system. Then it goes to [America's] Kurion's system for oil/technetium removal, then cesium removal, then iodine removal. Then it goes to [France's] Areva's system for further decontamination, and finally arrives at Hitachi's desalination system. [1]

...

The TEPCO radioactive water treatment system was successfully started on Friday, June 17, 2011 at 8 PM EST and then stopped on Saturday, June 18, 2011 at 12:54 AM EST.  It took only 5 hours before a component in Kurion, Inc.'s (the U.S. company) system, which uses zeolite to filter out radioactive cesium, reached it's radiation saturation limit.  Under normal circumstances, replacements to this component do not need to be made for about 30 days.

According to EX-SKF TEPCO is addressing the issue by re-organizing the filtration process across all of the various components as well as restricting the flow rate of radioactive water coming in to the system to reduce the radiation exposure to the Kurion system component(s). [1]

References:
[1] Contaminated Water Processing at #Fukushima: TEPCO Says Water Is "Hot", But The System Can Handle It, EX-SKF blog