The Chinese Embassy in Japan on Tuesday criticized Japan's plan to dump radioactive wastewater from the crippled Fukushima Daiichi Nuclear Power Plant into the Pacific Ocean, urging the Japanese side to handle the nuclear-contaminated water in a "science-based, safe and transparent" manner.

Discharging the contaminated water into the ocean lacks legitimacy, poses huge risks to the global marine environment and mankind, and violates international rules and obligations, Chinese Ambassador to Japan Wu Jianghao told a press conference.

China urges Japan to face up to the legitimate concerns of the international community and people in Japan and stop forcibly proceeding with its discharge plan, Wu added.

He said that Japan unilaterally made the decision and announced it to the public without consulting neighboring countries, effectively imposing it on all parties as the only option.

Wu said there were at least five other options but Japan had chosen to ignore them.

The nuclear-contaminated water had direct contact with the reactors' cores melt during the Fukushima nuclear accident, and it contains over 60 radionuclides, many of which cannot be treated effectively with existing technologies, he said. Some long-lived radionuclides may spread with ocean currents and form a bioconcentration effect, which will multiply the total amount of radionuclides in the environment, he added.

Such discharge violates Japan's obligations to protect and preserve the marine environment as outlined in United Nations Convention on the Law of the Sea and other international laws and the provisions against dumping radioactive wastes from man-made structures at sea in the London Convention, he said.

Noting there was no precedent of disposing over 1.3 million tonnes of nuclear-contaminated water of such a complex composition, Wu questioned the effectiveness and maturity of the Advanced Liquid Processing System (ALPS), a multi-nuclide removal system, which has not been certified after third-party evaluation.

He further questioned Japan's use of the report by the International Atomic Energy Agency (IAEA) to prove its legitimacy and legality of discharge, saying it cannot be a "pass" as Japan had issued and approved the discharge plan long before IAEA's working group completed its assessment and released the final report.

He added that the IAEA is an international agency that promotes the safe and peaceful use of nuclear technology, which is not an appropriate party for assessing long-term effects of nuclear-contaminated water on the marine environment and biological health. Besides, the Japanese side had restricted the mandate of IAEA's working group from evaluating alternative disposal options, he stressed.

It is basic scientific common sense that the nature of the contaminated water from the Fukushima nuclear accident is different from the normal operating drainage of a nuclear power plant as they come from different sources and have different types of radionuclides, Wu noted.

He said Japan's use of dilution to reduce the concentration of radioactive substances in nuclear-contaminated water without controlling the total quantity of all radionuclides is tantamount to downplaying the hazards and is contrary to science.

Wu said that China has repeatedly expressed its views and concerns from a professional perspective, but the Japanese side has insisted on pushing forward its scheduled discharge plan. If Japan is sincere in consultation, it should suspend the plan, agree to discuss all possible disposal options, and allow stakeholders to conduct independent sampling and analysis, effectively addressing the concerns of all parties, he added.

Despite ongoing opposition from within the country and abroad, Japan has been rushing to carry out its plan to dump radioactive wastewater into the Pacific Ocean, causing growing anger and stoking fears in the global community.

Japan's Chief Cabinet Secretary Hirokazu Matsuno said on Monday that the country will not change its plan to discharge Fukushima nuclear-contaminated water in the summer, local media outlet Jiji Press reported.