On August 29th, the New York Times the article Japan’s $320 Million Gamble at Fukushima: An Underground Ice Wall. (1) The report is fraught with speculations and FUD – appeals to Fear, Uncertainty, and/or Doubt – with respect to Fukushima’s impermeable “ice wall” project. The Times is usually a source of reliable information, but the newspaper fumbled this one.
In the fourth paragraph, the speculations begin. While correctly stating that the ice wall will act as a dam to keep groundwater from flowing into the basements of the four damaged F. Daiichi units, it incorrectly says, “It will also help stop leaks of radioactive water into the nearby Pacific Ocean.” Actually, the ice wall has nothing to do with the assumptive leakage of contaminated groundwater into the Pacific. Either the Times failed to keep up with Tepco postings about the ice wall over the past year, or the news outlet doubts the utility’s reports. Actually, a steel and concrete impermeable wall has been sunk deeply into the earth along more than 700 meters of the shoreline to prevent contaminated groundwater reaching the sea; not the inland ice wall.
The Times report mentions that Tepco’s shore-line wall has stopped all “measurable leaks” to the open sea. But, uncertainty and doubt are immediately injected with the statement, “Some scientists say that radioactive water may still be seeping through layers of permeable rock that lie deep below the plant, emptying into the Pacific far offshore.” As we shall soon see, this is not true. No such permeable layer exists that extends far out to sea, and never has existed.
The Times says Tepco built the power station by cutting away the shore’s hillside, which is true. But, this was not done “so that the plant could pump in water more easily.” The hillside was actually lowered (not removed) to facilitate building a break-walled harbor so that large, heavy plant equipment (like the reactor pressure vessels) could be shipped in without use of roads or railroads. Thus, we have a completely unfounded speculation.
Immediately following is the false assumption about the plant being built on permeable rock. The Times says the hillside removal “…put the buildings in contact with a deep layer of permeable rock filled with water…” The underlying bedrock beneath the plant is impermeable metamorphic ge0ology (granitic)! (2,3) There was some sandstone above the bedrock that terminated at the cliff along the pre-construction shore-line, but it did not extend “far out to sea”. The sandstone was removed to effect the port’s construction, then backfilled with soil and gravel which now surrounds the basement walls. The groundwater flow is above the bedrock through the mixture of soil and gravel. The rock under the reactor buildings is not permeable, so it cannot be filled with water.
Next we have two overlapping fallacious statements. The first concerns the in-leakage of ground water (plus leaks from the damaged units), “The continual flood of radioactive water has prevented engineers from searching for the (formerly molten) fuel.” The actual reason for not yet making a physical search is the high radiation levels inside the Primary Containments of units #1, 2 & 3! Staff could only spend a precious few minutes in such an environment before exceeding an exposure limit. In addition, the Times says no-one knows where the re-solidified fuel (corium) is located. Muon tomography has shown that the greater majority of the corium for unit #2 is inside the reactor Pressure Vessel’s bottom head, while a small fraction still remains in the core barrel above the head. It did not melt “…through the reactor’s steel floors and possibly into the basement underneath.” It seems the NY Times is trying to keep uncertainty and doubt alive concerning location of the corium at F. Daiichi.
Subsequently, The Times tries to connect the constant build-up of stored water in nearly 1,000 large tanks to the ice wall. To the contrary, the massive storage problem has nothing to do with the ice wall. About 95% of the water now stored in these tanks has been purified, removing all but one of the contained radioactive contaminants. The remaining isotope is Tritium; a biologically-harmless, albeit naturally-occurring form of Hydrogen. The only reason these hundreds of thousands of gallons of cleansed waters are not being released to the sea is radiation-based misconceptions and rumors about “tainting” the food-fish caught off the Tohoku coast. Nothing of the sort would happen if it were all released, but extreme radiophobia is a powerful hurdle to overcome in Japan.
Next, the Times continues the onslaught of uncertainty and doubt. While freezing large volumes of soil has been successfully used to bore massive tunnels around the world, the Times adds, “…but not on this scale. And certainly not on the site of a major nuclear disaster,” which really makes no difference. But, anything associated with a nuclear plant is always made to seem unique and inordinately iffy. In addition, the Times evokes unidentified “skeptics” who infer that the ice wall is actually “more like a sieve” because a fraction of a percent of the wall has yet to fully freeze and Tokyo requires that a half-dozen sections must not be solidified.
Then, unidentified critics are evoked who say the ice wall is merely a temporary fix, the refrigerant is corrosive and could fail catastrophically, and (of course) no-one knows how the technology will hold up “in a high radiation environment”.! The Times obviously doesn’t know that a high radiation zone is defined as having exposure levels in excess of 100 millisieverts per hour. (4) None of ice wall comes close to this level.
In closing, the Times cites a former construction minister (I cannot find a listing for a Construction Ministry in Japan) who makes the following provocative statement, “Why build such an elaborate and fragile wall when there is a more permanent solution available?” He wants a 100 feet deep, mile-long trench dug around the four buildings and filled with “liquid concrete that is commonly used to block water.” Thus, a speculation is offered as the ultimate solution! But, the article overlooks the fact that flow of contaminated water into the four damaged unit’s basements will continue because of leaks cooling water pumped into units #1, 2, & 3! The ice wall might stop the influx of groundwater, but not the hundreds of gallons per day from system leaks!
The waste water problem at F. Daiichi is not what the Times purports. The problem is, was, and will continue to be Japan’s widespread fear of the radiation bogeyman.
1 – http://www.nytimes.com/2016/08/30/science/fukushima-daiichi-nuclear-plant-cleanup-ice-wall.html?smid=fb-nytscience&smtyp=cur&_r=1
2 – https://www.researchgate.net/publication/285694770_Geology_and_petrography_of_the_Abukuma_granites_in_the_Hiyama_district_Fukushima_Prefecture_NE_Japan
3 – http://www.fukushima-blog.com/article-the-geology-of-fukushima-88575278.html
4 – https://www.remm.nlm.gov/zones_radincident.htm