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:
...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.
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. 
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). 
 Contaminated Water Processing at #Fukushima: TEPCO Says Water Is "Hot", But The System Can Handle It, EX-SKF blog