This photo shows tanks in Fukushima Daiichi nuclear power plant storing contaminated wastewater. (Tokyo Electric Power Co.)

A daily briefing by the Seoul government on Japan's release of treated radioactive wastewater into the sea will be held to address fears over the toxicity and impact to marine life, officials said Thursday.

Government officials held their first briefing on Thursday over some 1.3 million cubic meters of water set to be released from the wrecked Fukushima Nuclear Power Plant. The briefing, also attended by independent experts, will take place on weekdays for the time being. A spokesperson declined to comment on how long the daily briefings would last.

The decision came after lawmakers expressed "much graver concerns than expected" about the wastewater disposal plan during a parliamentary questioning of Prime Minister Han Duck-soo at the National Assembly this week, said Park Ku-yeon, first vice minister of government policy coordination, in a press conference at the Government Complex Seoul.

"The government is putting its utmost effort into ensuring Korean people's safety, but on the other hand, we should also avoid circumstances where concerns arise due to the lack of information or spread of misinformation," Park said.

"That's how we made the decision to frequently provide scientific information (about Japan's plan) and use the briefings as a means of communication (with the public)," he continued.

Park refuted during the briefing claims raised by detractors, including the lawmakers of the main opposition Democratic Party of Korea, who are against the discharge of the wastewater.

He said media reports about the "poor sampling" of the wastewater by the International Atomic Energy Agency, which cited an official of Tokyo Electric Power Company, the operator of the Fukushima Daiichi Nuclear Power Plant, during a seminar hosted by Democratic Party were false. The sampling was taken from "fully blended" wastewater under the supervision of the IAEA, Park said, adding that the government had verified the information with the IAEA.

Park also refuted claims that the wastewater had shown a high activity concentration of radioactive nuclide strontium-90 at 433,000 becquerels per liter. The figure refers to the radioactivity of the wastewater before treatment, he said. A preliminary report in May by a task force under the IAEA, a UN body, showed that the treated water had an activity concentration of 0.42 becquerels per liter in the worst-case scenario.

Park also reiterated that the test Tepco conducted earlier this week did not involve discharging actual wastewater.

Song Sang-keun, vice minister of the Ministry of Oceans and Fisheries, said in the same briefing that seafood in Korea has been proven safe for consumption in some 75,000 inspections since 2011, despite the Fukushima nuclear reactors' meltdowns and the leakage of contaminated water in 2013.

Song added that none of the 286 rounds of radioactivity inspections into salt produced in Korea were found to be contaminated.

Park Ku-yeon (second from left), first vice minister of government policy coordination, at a press conference at the Government Complex Seoul on Thursday. (Yonhap)

But the IAEA's latest report and recent findings have failed to alleviate public fears, as the Japanese government is ready to discharge the wastewater over the course of the next three decades, it says, if it receives approval by the IAEA with its final announcement anticipated later in June. A disapproval from the IAEA, on the other hand, will force Japan to hold off on its plan to discharge of the wastewater disposal plan.

The preliminary report in May by IAEA indicated that Tepco's wastewater treatment technology showed "a high level of accuracy" and found that tritium is the only radionuclide that had higher activity concentrations -- as expected -- than safety standards.

In 2013, Tokyo acknowledged there had been a leakage of contaminated water in August 2013 after a series of denials.

That same year, Korea imposed a ban on imports of from eight prefectures -- Aomori, Miyagi, Iwate, Fukushima, Ibaraki, Tochigi, Gunma and Chiba -- and asked for certificates for imports from eight others -- Hokkaido, Tokyo, Kanagawa, Aichi, Mie, Ehime, Kumamoto and Kagoshima.

The import curbs prompted Japan to take legal action, though the World Trade Organization ruled in favor of Korea in 2019.

Park said such import restrictions are "at the toughest level in the world," reiterating the government's position not to lift the ban and blaming Japan for its failure to assure Seoul of the safety of its seafood.

In the meantime, Song criticized the Democratic Party of Korea's proposal of a bill to create legal grounds to compensate fishermen in Korea for damages, saying it is premature to introduce a law when no damages have been found yet.

As to how the wastewater discharge plan to the sea was confirmed, Heo Gyun-young, a nuclear engineering professor at Kyung Hee University in charge of Korea's independent technology review on the plan, said Japan's plan to dump the wastewater into the sea is the most viable option. It is preferable to disposing of it through the air given that radioactive elements become harder to contain once wastewater evaporates.

Heo added that no options -- including burying the wastewater on Japanese soil -- have been proven safe scientifically.