<mix...@bigpond.com> wrote:
> >Japan is to invest hundreds of millions of dollars into building a > >frozen wall around the Fukushima nuclear plant to stop leaks of > >radioactive water. > > ...and what happens when the enclosure fills up? > It is filled up now. That is to say, the ground is saturated with groundwater. The idea is to stop more ground water from entering. In other words, it is a like a giant wall, or box, that extends below the ground to a level lower than the usual flow of ground water. The incoming ground water will then come up against it, from the uphill side. It will fill up wells drilled on the outside of the wall. These wells will have be continuously pumped out and drained into the ocean. This stops the water from percolating through the contaminated dirt. The contaminate dirt is between the wall and the ocean. Japan has lots of rain. Everyplace I have been to has lots of groundwater, easily tapped for a well. After rain, it pours out of rocky cliffs and retaining walls. Retaining walls always have drainage pipes or gaps built into them to let the water out. I thought this technique was new, but Japanese experts quoted in the New York Times say it has been used in construction projects such as the Big Dig in Boston. However, it has never been employed on such a large scale. This will take prodigious amounts of energy to maintain. That is, to keep it frozen and to pump out the accumulating ground water from behind the wall. - Jed
