The disaster at Japan's Fukushima nuclear power plant may no longer be daily news, but the situation is far from under control.
Fukushima Daiichi Nuclear Power Plant after the tsunami/Getty images
More than two months after the Japan earthquake and tsunami caused massive damage to the Fukushima Daiichi nuclear power plant, the disaster has dropped out of the daily news. But that doesn’t mean nothing is happening.
Since the Listener’s first article about the nuclear accident on March 26, the disaster has been upgraded to a 7 on the international nuclear accident scale. After being accused of evasiveness and a lack of transparency over the accident, the company that runs the power station, Tepco, has finally confirmed the meltdown of reactor one – and possibly reactors two and three – may have breached the primary containment vessel, and that radioactive water used to cool the plant has leaked into the ocean. The worst-case scenario – an explosion and fire that releases massive amounts of radionuclides into the atmosphere – has not eventuated, but the situation is far from under control.
“It’s kind of in a Band-Aid stage,” says University of Auckland nuclear physicist David Krofcheck. “They’re pumping radioactive water from the bottom of these primary containment vessels into storage tanks.”
Part of Tepco’s “Road-map Towards Restoration” involves installing a closed-loop cooling system in which water absorbs heat from the nuclear fuel, evaporates into steam and goes through a condenser to be converted back into water. After this process, radionuclides like caesium-137 will be stripped out and the water pumped back into the reactor.
But until this system is in place, any radioactive water coming out of the plant must be stored. In late May, Tepco announced a makeshift water storage facility, capable of holding 10,000 tonnes of irradiated water, was near capacity.
Meanwhile, a “mega-float”, also capable of storing 10,000 tonnes of water, has been berthed at a quay outside the plant.
If the worst hasn’t happened – though there is still the risk of an aftershock causing further damage, including another hydrogen explosion – how bad is the reality?
In March, Helen Caldicott, an Australian paediatrician and founding president of Physicians for Social Responsibility, said the situation at Fukushima was already “by orders of magnitude, many times worse than Chernobyl”. She was speaking at a press conference to endorse a controversial scientific report that says almost a million people have died from the effects of the Chernobyl disaster.
Speaking on the phone from an Auckland hotel last week, Caldicott described what’s happening at Fukushima as “kind of like a nuclear war with no explosion”. She believes the release of radionuclides from Fukushima is much higher than has been reported by officials and could, over time, cause millions of cancers. Those cancers are in addition to any already caused by, or yet to be caused by, radiation from the Chernobyl accident and atmospheric bomb tests from the 1950s and 60s.
“But we’re not just talking about cancers,” she says. “We’re talking about random compulsory genetic engineering for the rest of time. And almost all mutations are deleterious. They cause diseases like cystic fibrosis, diabetes, dwarfism – there are over 2600 genetic diseases – I could go on and on. So what we are doing is just the most ghastly experiment, not just on the human species but on 30 million other species that cohabit the planet with us.”
Caldicott says with solid tumour cancers often not appearing for 15-60 years after exposure to radiation, we have yet to see the full impact of atmospheric bomb testing or nuclear accidents on public health.
Ken Buesseler, a chemical oceanographer at the Woods Hole Oceanographic Institution, agrees when it comes to the oceans, the impact of Fukushima is greater than Chernobyl, with levels of some radionuclides “at least an order of magnitude higher than the highest levels in 1986 in the Baltic and Black seas, the two ocean water bodies closest to Chernobyl”.
But what does this release of Fukushima radionuclides into the ocean mean? According to the Woods Hole Oceanographic Institution website, our oceans carry about two million curies of radioactive caesium-137 from the Chernobyl nuclear accident, which occurred 25 years ago. Compare this, though, with the caesium-137 still in the oceans from the nuclear-weapons tests of the 1950s and 60s (36 million curies) and the radioactivity from naturally occurring radionuclides like uranium-238 and potassium-40 (more than 400 billion curies).
But there is still a danger of more radioactive water leaking into the ocean next to the Fukushima plant, and New Zealanders might want to know if these radionuclides are likely to reach our shores.
“There is some mixing between the Northern and Southern Hemisphere oceans but really, much like the atmosphere, the two systems are pretty isolated,” says Philip Sutton, an oceans specialist at the National Institute of Water & Atmospheric Research. “But the sheer quantity of water in the oceans means the contaminant that’s gone in just gets diluted down. The fallout from Chernobyl, which was air based, settled on land, and once it settled it was pretty much there, so things like grazing stock could be an issue, but in the ocean, away from the source, it doesn’t settle, it keeps getting mixed and stirred and moved around.”
Sutton believes that if any radioactive isotopes from Fukushima did reach New Zealand, they would be at trace levels and unlikely to be detectable.
Some scientists, including spokespeople from the International Atomic Energy Agency and physicists from our National Radiation Laboratory, emphasise that outside the safety zone around the plant, the health effects of any radioactive material released at Fukushima will be insignificant compared with natural annual background radiation. However, Caldicott points out there is no “safe” radiation dose.
Radiation exposure is cumulative, and the more ionising radiation you are exposed to, the higher your risk of cancer. Therefore, says Caldicott, the recent decision to increase the permissible radiation dose of schoolchildren in the Fukushima area to 20 millisieverts a year – comparable to that of radiation workers in Germany – is “absolutely criminal” as “children are 10 to 20 times more radiosensitive than adults”. (After a public outcry, Japanese officials have since changed the permissible dose back to 1mSv.)
But if the officials thought 20mSv would be safe, who should the public listen to? “To the doctors,” says Caldicott. “The physicists might know about the different sorts of radiation, they might know about E=mc2, and the engineers know about construction, but they don’t know radiation biology.”
In defence of physicists, Tony Cotterill points out his training is in “medical and health physics” and that he and his colleagues from the National Radiation Laboratory have expertise in radiological protection and environmental radiation protection. “I think the situation is still very serious,” he says of Fukushima. But he also points out that “although one must be very careful when making such comparisons, the amount of radioactive material released by the nuclear-weapons testing was orders of magnitude greater than that released to the atmosphere at Fukushima” – and only a tiny fraction of the natural background radiation with which we have all evolved.
There’s one thing doctors and physicists seem to broadly agree on: we don’t yet know the full extent of release of radionuclides from Fukushima, and only time will reveal the full impact on public health.