Via The New York Times: Japan’s ‘Hail Mary’ at Fukushima Daiichi: An Underground Ice Wall. Excerpt:
FUKUSHIMA DAIICHI NUCLEAR POWER STATION — The part above ground doesn’t look like much, a few silver pipes running in a straight line, dwarfed by the far more massive, scarred reactor buildings nearby.
More impressive is what is taking shape unseen beneath: an underground wall of frozen dirt 100 feet deep and nearly a mile in length, intended to solve a runaway water crisis threatening the devastated Fukushima Daiichi Nuclear Power Station in Japan.
Officially named the Land-Side Impermeable Wall, but better known simply as the ice wall, the project sounds like a fanciful idea from science fiction or a James Bond film. But it is about to become a reality in an ambitious, and controversial, bid to halt an unrelenting flood of groundwater into the damaged reactor buildings since the disaster five years ago when an earthquake and a tsunami caused a triple meltdown.
Built by the central government at a cost of 35 billion yen, or some $320 million, the ice wall is intended to seal off the reactor buildings within a vast, rectangular-shaped barrier of man-made permafrost. If it becomes successfully operational as soon as this autumn, the frozen soil will act as a dam to block new groundwater from entering the buildings. It will also help stop leaks of radioactive water into the nearby Pacific Ocean, which have decreased significantly since the calamity but may be continuing.
However, the ice wall has also been widely criticized as an expensive and overly complex solution that may not even work. Such concerns re-emerged this month after the plant’s operator announced that a section that was switched on more than four months ago had yet to fully freeze.
Some also warn that the wall, which is electrically powered, may prove as vulnerable to natural disasters as the plant itself, which lost the ability to cool its reactors after the 45-foot tsunami caused a blackout there.