Explained | Row over planned release of radioactive water from Japan's Fukushima nuclear plant

Japan beganreleasing millions of tonnes of treated radioactive water from the tsunami-hit Fukushima nuclear plant into the Pacific Ocean on Thursday (August 24), a move that has already triggered strong opposition from neighbouring countries.

An estimated 1.34 million tonnes of radioactive water— enough to fill 500 Olympic-size pools—hasaccumulated in the tank at the site since the 2011 tsunami incident.

The water will be released over 30 years after being filtered and diluted.

The Tokyo Electric Power Company (Tepco)—the nuclear plant’s operator—has been designated to execute the plan.

The release of water has starteda month after Japan’s nuclear regulator gave the nod to Tepco to start releasing the water, which has been termed “safe” by the Japanese government and the International Atomic Energy Agency amidst fears expressed by neighbouring countries that the water may contaminate food.

How will contaminated water get discharged?

The 1.3 million tonnes of radioactive water that is stored in huge tanks on the site has been filtered through Tepco’s advanced liquid processing system (Alps) to remove most radioactive elements except for tritium—an isotope of hydrogen that is difficult to separate from water.

The “treated” water, as Japan has objected to the use of the word “contaminated”, will be diluted with seawater so that the concentration of tritium is well below regulatory-approved levels before being released into the ocean onekilometre from the shoreline via an undersea tunnel.

This practice is common around the world and regulatory authorities support dealing with the Fukushima water in this way.

According to experts, tritium is relatively harmless as its radiation is not strong enough to affect human skin.

When ingested at levels above those in the released water, it can raise cancer risks, a Scientific American article said in 2014.

It is estimated that the water discharge would take decades to complete, with ongoing filtering and dilution, alongside the planned decommissioning of the plant.

The safety concerns

Though the Japanese government and the IAEA have asserted that the so-called “treated” water is safe, environmental activists have raised concerns arguing that all the possible impacts have not been studied.

The UN nuclear watchdog, which approved the plan in July, says that Japan is meeting the international standards of discharging the water and reiterated that it would have a “negligible” impact on people and the environment.

On Tuesday(Aug 22), Greenpeace said that the radiological risks have not been fully assessed and that the biological impacts of tritium, carbon-14, strontium-90 and iodine-129 —to be released with the water —"have been ignored”.

ButTepco and Japan have argued that the filtering process will remove strontium-90 and iodine-129, adding that the concentration of carbon-14 in the contaminated water would be far lower than its regulatory standard for discharge.

The government will take "appropriate measures, including immediate suspension of the discharge" if an unusually high concentrationof radioactive materials is detected, the Japanese government document said, according to Reuters news agency.

The South Korean government, too, concurred with Japan, saying that its own study conducted recently has indicated that the water release meets international standards and said it respects the IAEA's assessment.

The opposition

Apart from Japan’s neighbouring countries, many people, including fishermen in Japan, have expressed opposition fearing that the discharged treated water might affect their livelihoods.

On Tuesday, a crowd of protesters staged a rally outside the prime minister's official residence, urging the government to stop the release.

But the most vocal opposition came from China, which accused Japan of treating the ocean like its "private sewer."

Chinese Foreign Ministry Spokesperson Wang Wenbin reiterated Beijing's objection on Tuesday, adding it would take "necessary measures to safeguard the marine environment, food safety and public health".

Japan is "putting its own self-interest over the long-term well-being of all humankind" with the release of wastewater, Wang said.

Hong Kong said it would "immediately activate" import curbs on some Japanese food products.

Both South Korea and China have already banned fish imports from around Fukushima.

Hong Kong's ban on Japanese seafood

Hong Kong Chief Executive John Lee said the release was "irresponsible" and posed "impossible risks to foodsafety" and risked "irreparable pollution and destruction of the marine environment".

Lee, in a post on his Facebook account, said he had told Environment Secretary Tse Chin-wan and relevant departments to immediately activate import controls to protect food safety and public health.

"There is no timetable at this point about how long the ban will last," Tse told a press conference, adding that a decision would depend on data and information from Japan after the discharge.

The measure covers live, frozen, refrigerated, dried aquatic products, sea salt and seaweed.

Hong Kong is Japan's second-largest market, after mainland China, for agricultural and fisheries exports.

(With inputs from agencies)

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