by Thom Kilburn
Radioactive water from the Fukushima nuclear reactors in Japan could reach the US West Coast in the next four years, according to recent simulations carried out by oceanographers. The environmental impact has already been felt around the globe.
The Fukushima I Nuclear Power Plant is the site of the largest nuclear disaster since the Chernobyl catastrophe of 1986. Damage caused by the tsunami in March 2011 led to equipment failures, nuclear meltdowns and releases of radioactive materials into the region and ocean. With the exception of Chernobyl, it was an unparalleled nuclear disaster from which fallout will seen in the environment for years to come.
Through a litany of observational studies, environmental experts across the board have begun to understand the detriment Fukushima’s spreading radioactivity will have on Pacific-based ecologies.
But why are these experts worried? Jota Kanda of the Tokyo University of Marine Science and Technology estimated last year that about 0.3 terabecquerels (TBq) of radioactive material are being spewed into the ocean each month. A becquerel is a unit of measurement for radioactivity (with tera being the prefix for trillion.)
This past August, the Tokyo Electric Power Company (TEPCO) released the figures of 0.1 to 0.6 TBq per month for caesium-137 and 0.1 to 0.3 for strontium. Caesium and strontium are the fission fragments left over after uranium-235 undergoes nuclear fission—the process used to generate power at nuclear plants such as Fukushima.
Although the amount of monthly radioactive leakage varies within TEPCO’s figures, it continues to this day.
Over the course of the past two years following Fukushima’s meltdown, the radioactivity has spread all throughout the Pacific Ocean. According to a study on the radioactivity dispersion by Claus Böning and Erik Behrens, oceanographers from the Helmholtz Centre for Ocean Research, the waste from the Fukushima nuclear reactors will soon double the radioactivity of U.S. coastal waters.
They used global ocean circulation models to simulate the movement of a tracer that was continuously injected into Japanese coastal waters over several weeks. Böning and Behrens then recorded its spreading and dilution in the Pacific Ocean over the course of 10 years.
“We were of course not surprised that there is a mixing effect, but we were surprised at how quickly the tracer spread,” said Böning in a recent interview with Environmental Research Web. “Within one year it will have spread over the entire western half of the North Pacific and in four years we predict it will reach the U.S. West Coast.”
However, Böning points out that the level of radioactivity will be much lower than what was released into the surrounding waters of Fukushima.
Some U.S. residents are beginning to report trace amounts of radiation in water. Reports in northern Alaska say that radiation has already arrived at the coast and concerns over contamination of fish and wildlife have mounted.
Douglas Dasher, a researcher at the University of Alaska Fairbanks says that more may be heading toward coastal communities, such as Haines and Skagway. He predicts that radiation levels in Alaskan waters could reach Cold War levels as a result of radioactivity dispersion from Fukushima.
“The levels they are projecting in some of the models are in the ballpark of what they saw in the North Pacific in the 1960s,” Dasher said.
Even the far south of the American coast is seeing effects from the nuclear meltdown. Southern California has experienced transitive exposure to radiation possibly from Fukushima.
Pacific bluefin tuna migrating from coastal Japan to the waters off southern California contained radioactive cesium isotopes from the nuclear disaster. The amount of radioactivity in the fish was one-tenth the level the U.S. and Japan consider to be dangerous, and likely posed minimal public-health hazard or risk to people who ate Pacific seafood. Although the levels are within safe limits for human consumption, the bluefin tuna demonstrate how such pollution can be carried vast distances by migratory species.
However, meeting regulatory standards does not necessarily imply a lack of long-term risk.
Caesium-134 and caesium-137 were both found in Pacific bluefin tuna caught near San Diego months after the nuclear meltdown at Fukushima. The fish spawns in the western Pacific; some juveniles stay in Japanese waters while others swim east to the California Current Large Marine Ecosystem, generally when they are around a year old.
While most oceanographers and environmentalists, such as Böning and Dasher, assert that the disposing of radioactive materials into the Pacific is grievously irresponsible, others argue the contrary saying that all radioactive water can safely be dumped into the ocean.
“The ocean would be the safest place for the waste water,” said Geraldine Thomas, who runs the Chernobyl Tissue Bank at Imperial College London.
“But to make that politically acceptable they have to talk to the local population. They have to make people understand that low levels of radiation don’t matter because we’re all exposed to it all the time.”
Not all experts agree on the alleged safety of exposure to radioactive materials via water or seafood consumption, though.
“You have to hand it to the nuclear industry and its acolytes,” said Peter Karamoskos, Ph.D., nuclear radiologist and public representative on the radiation health committee of the Australian Radiation Protection and Nuclear Safety Agency.
“In the middle of the second-worst nuclear power disaster in history at Fukushima, and with still no end in sight, you would think they would respond with contrition, humility and profuse mea culpas,” said Karamoskos. “Not on your life. The industry representatives and its acolytes came out swinging in full denial attire.”