MICHAEL BLEBY: Japan’s F-word rears its head again

You no doubt remember Japan’s earthquake, tsunami and nuclear reaction meltdown of March 11 2011. A magnitude 9.0 shook the northeastern coast of Honshu, the country’s main island, triggered a tsunami with 10m and higher waves and the damage was immense.

About 20,000 people died. The quake and resulting seismic sea wave also hit the string of nuclear power plants along the country’s Pacific coast, causing the cooling system to fail at one of Tokyo Electric Power Co’s (Tepco’s) facilities.

Three reactor cores in the Fukushima Daiichi Nuclear Power Station overheated, with nuclear fuel melting and breaching the walls of the containing buildings. Explosions in three reactors released an estimated 538.1 petabequerels of radioactivity into the atmosphere in the days after the quake.

It was not the worst nuclear disaster in recent history — the volume of radiation was about one-tenth of that unleashed in the Chernobyl meltdown of 1986 — and much of the concern about health was averted as winds blew emitted radionuclides into the Pacific.

But in addition to the many lives lost in the tsunami, the meltdown devastated the local agricultural and fishing industries. The overall catch of fish from the area is still only 20% of its pre-accident levels. Produce from Fukushima (which ironically translates as “blessed island”) was long seen as tainted, a blight from which it is only now recovering.

And Japan’s F-word is casting a cloud again as the country prepares to release 1.3-billion litres of wastewater used to cool the stricken power plant into the ocean.

The issue tears at the fault lines between a belief in science and confidence in governments to do the right thing. In 2012, in the wake of the devastating accident, critics said Tepco and regulators for years had ignored warnings about the risk of larger-than-expected tsunamis.

Japan has now accumulated more than 1,000 tanks of water holding 1,000 cubic metres each. Last week the International Atomic Energy Agency (IAEA) gave Japan the nod to go ahead with the plan formulated over a decade. It could start within months.

It’s partly a real estate problem — the power company is running out of space to store the used water — and also a procedural one: Tepco needs to get rid of the water to get on with shutting down the plant permanently.

They’ve constructed a pipe stretching 1km offshore to pump out the water. Japan says it will be diluted to levels of radioactivity below those occurring naturally.

So is the water safe? Yes, the government says, pointing out that a number of countries follow the same process of disposing of water from nuclear power plants. The water stored has been purified to remove the vast majority of the 62 radioactive chemicals in it (including nasties such as caesium and strontium) with mainly tritium remaining.

Dilution of the tritium, a radioactive isotope of hydrogen, to 1,500 becquerels per litre (Bq/l) is one-seventh of the World Health Organisation’s drinking water standard of 10,000 Bq/l.

Japan says it will pump out the seawater-diluted wastewater over a
40-year period at what it says is a maximum volume of 22TBq (Terabecquerels) per year, less than plants in China and Korea flush out.

The modelled effects on the flatfish, crabs and brown seaweed that frequent the waters of the release area are benign, the IAEA report says.

But we still don’t know what we don’t know.

“Whereas the effects of radiation exposure on human health are relatively well understood ... the effects of radiation on the environment are under continuous investigation,” the IAEA says in its own report on the Japan plan.

And past history — as well as more recent incidents — can feed doubt about official reassurances. An eruption of steam late in June from a geothermal energy research project by Mitsui Oil on the northern island of Hokkaido was left uncapped for a week and surrounding waterways have been found with toxic levels of arsenic since then.

Critics, such as University of Hawaii biologist Robert Richmond, a consultant to the Pacific Island Forum, a regional grouping, argue the Fukushima washout is not proven to be safe and that lack of certainty is reason not to do it.

But the IAEA has given the nod and hopes it will be successful. “The discharge of the water must be managed to protect future generations and their environments in such a way as to avoid imposing an undue or uncontrolled burden on future generations,” it says.

The fishers of Fukushima will no doubt agree.

• Bleby is a senior reporter with The Australian Financial Review in Melbourne.