By Yuri Kageyama
12 April 2016
TOKYO (AP) – To dump or not to dump a little-discussed substance is the question brewing in Japan as it grapples with the aftermath of the nuclear catastrophe in Fukushima five years ago. The substance is tritium.
The radioactive material is nearly impossible to remove from the huge quantities of water used to cool melted-down reactors at the Fukushima Dai-ichi plant, which was wrecked by the massive tsunami in northeastern Japan in March 2011.
The water is still accumulating since 300 tons are needed every day to keep the reactors chilled. Some is leaking into the ocean.
Huge tanks lined up around the plant, at last count 1,000 of them, each hold hundreds of tons of water that have been cleansed of radioactive cesium and strontium but not of tritium.
Ridding water of tritium has been carried out in laboratories. But it's an effort that would be extremely costly at the scale required for the Fukushima plant, which sits on the Pacific coast. Many scientists argue it isn't worth it and say the risks of dumping the tritium-laced water into the sea are minimal.
Their calls to simply release the water into the Pacific Ocean are alarming many in Japan and elsewhere.
Rosa Yang, a nuclear expert at the Electric Power Research Institute, based in Palo Alto, California, who advises Japan on decommissioning reactors, believes the public angst is uncalled for. She says a Japanese government official should simply get up in public and drink water from one of the tanks to convince people it's safe.
But the line between safe and unsafe radiation is murky, and children are more susceptible to radiation-linked illness. Tritium goes directly into soft tissues and organs of the human body, potentially increasing the risks of cancer and other sicknesses.
"Any exposure to tritium radiation could pose some health risk. This risk increases with prolonged exposure, and health risks include increased occurrence of cancer," said Robert Daguillard, a spokesman for the U.S. Environmental Protection Agency.
The agency is trying to minimize the tritium from U.S. nuclear facilities that escapes into drinking water. […]
Japan's fisheries organization has repeatedly expressed concerns over the issue. News of a release of the water could devastate local fisheries just as communities in northeastern Japan struggle to recover from the 2011 disasters.
An isotope of hydrogen, or radioactive hydrogen, tritium exists in water form, and so like water can evaporate, although it is not known how much tritium escaped into the atmosphere from Fukushima as gas from explosions.
The amount of tritium in the contaminated water stored at Fukushima Dai-ichi is estimated at 3.4 peta becquerels, or 34 with a mind-boggling 14 zeros after it.
But theoretically collected in one place, it would amount to just 57 milliliters, or about the amount of liquid in a couple of espresso cups — a minuscule quantity in the overall masses of water. [more]