Fukushima Radioactive Waste Problems Metastasize

The Tokyo Electric Power Company, Tepco, reported on March 21 that two specially designed and newly installed robots will need three years to remove about 3,000 sandbags from the basements of the three destroyed reactor buildings at Fukushima-Daiichi, in Japan.

The sandbags were used in the panic-driven initial days of the triple reactor meltdowns of March 2011, when highly radioactive water gushed into the reactor basements and had to be diverted. Interesting Engineering reports that the sandbags are in areas “with lethal radiation levels” too hazardous for manual work.

The robots will be operated remotely due to the sandbags’ fierce radioactivity, because of the large bulk of the bags which weigh a total of 41 tons, and because of the chaotic wreckage in the destroyed reactors’ basements, the project is expected to take at least until March 2028, according to Tepco.

News reports did not specify the sort of radioactive materials that contaminate the deadly sandbags, but the melted reactor No. 3 was using fuel made partially of plutonium, the most toxic material known to science, which is radioactively hazardous for 240,000 years. Deadly isotopes beyond plutonium that make the high radiation zones too hot for humans include strontium-90, cesium-137 and -134, iodine-131, cobalt-60, carbon-14, tritium, technetium, neptunium, and americium.

Tepco says the deadly sandbags will be “sealed in dedicated containers” and moved to a temporary storage site. The company’s plan for long-term containment of this radioactive waste was not outlined and Tepco was not compelled by the press or the government to explain its strategy.

In Tokyo, the Citizens Nuclear Information Center (CNIC) reports that the sandbags have deteriorated, and cannot be recovered with the bags intact, forcing engineers to consider pumping them out together with the basement’s stagnant water, and then enclosing it all in containers.

Slow decommissioning at risk from quakes

Until at least 2027, the sandbags in addition to tons of highly radioactive sludge produced by filtering contaminated cooling water has to be kept in an area still at risk of flooding from potential earthquakes and tsunamis, the CNIC reported.

A March 31 report by Japan’s Cabinet Office’s disaster management working group says that a long-predicted “mega-quake,” if it occurs as anticipated along the Nankai Trough off Japan’s southwest Pacific coast, would likely trigger huge tsunamis, destroy thousands of buildings, spawn mass fires, cost Japan $1.81 trillion, and potentially kill 300,000 people. Under the report’s worst-case scenario, a magnitude-9 earthquake could see 1.23 million evacuees fleeing the area, or about 10% of its total population.

The Nankai trough is where the Philippine Sea Plate is subducting under the Eurasian Plate and accumulating tectonic pressure that can snap. The magnitude 9.1 undersea tectonic eruption of March 11, 2011 — Japan’s worst ever recorded earthquake whose power smashed reactor foundations at Fukushima Daiichi and flooded the site with tsunami waves — moved the island of Honshu, Japan’s largest, an astounding eight feet eastward.

Japan is one of the earth’s most earthquake-prone areas, and because of Fukushima’s daily accumulation of contaminated cooling water, some 1.3 million tonnes of this highly radioactive liquid waste is held in 1,000 giant tanks near the coast. So the sludge containers, the sandbags, and the 1,000 wastewater tanks are all vulnerable to daily tremors and the dreaded mega-quake.