South Korean experts began a two-day inspection of the disaster-hit Fukushima nuclear power complex Tuesday in connection with Japan's plan to discharge into the sea treated water from the plant containing low concentrations of radioactive substances.

The 21 experts in fields such as radiation and nuclear reactors intend to share the outcome of their inspection with the South Korean public amid concern about the potential impact of the discharge on the ocean environment.

Photo taken on Jan. 19, 2023, shows tanks storing treated radioactive water on the premises of the Fukushima Daiichi nuclear power plant in Fukushima Prefecture. (Kyodo)

On the first day of the inspection, the delegation observed an advanced liquid processing system set up at the crippled Fukushima Daiichi nuclear plant and confirmed its function -- how it removes radionuclides other than tritium.

The experts also inspected facilities to measure concentrations of tritium, water tanks and the control room, among others, according to delegation chief Yoo Guk Hee, chairman of the Nuclear Safety and Security Commission.

"We were able to see all the facilities we wanted as planned (for the day)," Yoo told reporters.

The Japanese government and the plant's operator, Tokyo Electric Power Company Holdings Inc., plan to begin releasing, around this summer, treated radioactive water 1 kilometer from the plant via an underwater pipeline after diluting it with seawater to below a 40th of the concentration permitted under Japanese safety standards for tritium.

The South Korean experts will hold discussions on the inspection with Japanese officials in Tokyo on Thursday before leaving the country on Friday.

"We would like to provide thorough explanations, including data. We hope that understanding regarding the safety of the discharge will deepen in South Korea," Yasutoshi Nishimura, Japan's minister of economy, trade and industry, said at a press conference.

Japanese Prime Minister Fumio Kishida and South Korean President Yoon Suk Yeol agreed during their meeting in Seoul earlier this month to send a delegation of South Korean experts to the Fukushima plant, with the countries' ties improving after a dispute over wartime labor compensation.

Since the 2011 nuclear crisis, vast amounts of water contaminated in the process of cooling melted reactor fuel has accumulated at the plant, mixing with rain and groundwater.

Neighboring China and Russia have expressed opposition to the discharge plan, as have local fishermen worried about the potential reputational damage to their products.

South Korea had also expressed concern about the plan, but government-backed research institutes released an analysis in February showing the discharge would not affect human health, as the concentration of tritium would be extremely low when it arrives in the country's waters about 10 years after release.

The discharge, which is expected to continue for decades, and its possible environmental impact are currently being reviewed by the International Atomic Energy Agency.

During their recent summit in Hiroshima, western Japan, the Group of Seven leaders endorsed the IAEA's review and Japan's transparent efforts.

"We support the IAEA's independent review to ensure that the discharge of Advanced Liquid Processing System (ALPS) treated water will be conducted consistent with IAEA safety standards and international law and that it will not cause any harm to humans and the environment," the leaders said in their communique released Saturday.

South Korea's Nuclear Safety and Security Commission chief Yoo Guk Hee (front) enters the Japanese Foreign Ministry in Tokyo on May 22, 2023. Yoo heads a South Korean delegation to assess the safety of Japan's planned release of treated radioactive water into the sea from the disaster-hit Fukushima nuclear power plant. (Kyodo)

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