Fukushima nuclear reactor cleanup suggestion

Cleaning the huge amount of radioactively contaminated water at the Fukushima nuclear reactor site has been declared an urgent task. See http://www.bbc.co.uk/news/science-environment-12908313 "Water clear-up 'urgent' at reactor." The article mentions that someone suggested using ion-exchange resins to filter the water before discharging the water safely. However, that means disposing of those resin filters afterwards. The article also mentions instead using the water to make concrete and then store the concrete somewhere.

Here is a different approach:

I had pointed out an alternate means, in a comment I left at some news site several days ago. It apparently has not reached the right ears. So I will point it out here, since there seems to be no communication path from me to the folks who can responsibly deal with the problem.

Back in the early 1960's, during the major nuclear scare where people were being given plans for emergency fallout shelters, it was told us that to decontaminate suspect drinking water, one could put some clay soil into the water in a jug, stir it up well and let the clay particles settle out until the water was clear. Then the water would be free of most of the radioactive particles, having been snagged by the clay and taken to the bottom of the container.

It seems such a process could be done there in Fukushima. Even right where floors and tunnels are said to be covered with ankle-deep radioactive contaminated water, by putting in some clay soil and stirring it up well then letting it settle out for a day, then pump out the clarified water on top, then shovel out the clay mud with the trapped radioactive particles in it, to be sun-dried into bricks for stashing in some abandoned mine, perhaps a worked-out former uranium mine that originally had far more radioactive rock removed from it in the past. Or they could first pump out the water and do the clay mixing and settling out in an external tank, which would have the advantage of not making a big cleanup job inside the facilities from the clay in an otherwise very clean environment, but have the disadvantage of getting contaminated pumps and hoses needing disposal. Pumping out and external settling would probably have less exposure of workers to the radiation overall, however, but take significantly longer to setup and do; the same external tank could be repeatedly refilled with pumped contaminated water and more clay stirred in, thus processing a much larger volume of water overall, until it became too filled with clay sludge and then needing to be scooped out and made into the aforementioned sun-dried bricks.

This process seems to enable a much larger volume of water to be processed quickly, and far cheaper and environmentally-friendly than using ion-exchange resin filters or using the water to make concrete.