Japan plans to soon discharge radioactive water from the Fukushima Daiichi nuclear power plant, which was crippled by a tsunami triggered by a massive earthquake off the northeast coast of Honshu in 2011, through a tunnel. The tunnel, completed in April, already contains about 6,000 tons of seawater, and is expected to channel the contaminated water from the plant to a point about 1 kilometer offshore.

Japan’s decision to discharge the nuclear-contaminated wastewater after the so-called Advanced Liquid Processing System process is “based on the premise of strict compliance with regulatory standards that have been established”. However, it is questionable whether Japan’s decision to directly discharge the radioactive wastewater, instead of considering four other options (geosphere injection, vapor release, hydrogen release and underground burial) is due to economic reasons or other “comprehensive considerations”.

Once discharged into the sea, the radioactive wastewater will contaminate the marine environment and ecosystem. Studies have shown that radioactive materials in the contaminated water will severely contaminate marine life, fish products and fishing grounds.

Given that the ocean is a complex system and radionuclides could be redistributed across oceans by currents and eddies, the radioactive wastewater will have a severe impact on the surrounding waters, from Japan’s coasts to the coasts of neighboring countries.

The impacts of the radioactive wastewater on marine life and thus human life demand that Japan change its decision and consider other ways of disposing of the wastewater, especially because studies show that the radioactive wastewater will affect the whole of the Pacific Ocean right up the western coast of North America.

The undersea tunnel Japan has built for the discharge of the radioactive wastewater has already created new problems for the implementation of existing treaties including the International Atomic Energy Agency’s conventions and the laws on ocean dumping (the London Convention and the London Protocol), but also the United Nations Convention on the Law of the Sea.

The IAEA was invested initially with the task of helping countries develop nuclear energy instead of protecting the environment for the betterment of humankind. Therefore, the international law applicable to Japan, in regard to its decision to dump radioactive wastewater, comes from the London Convention and the London Protocol, the UNCLOS and the general principles of international law.

Despite Tokyo arguing that the issue of radioactive contaminated water discharge “should not be discussed”, questions on the legality of Japan’s decision have been discussed at LC and LP meetings. And according to the LC and the LP, the legal status of the undersea tunnel is open for debate.

For example, if the tunnel is a “man-made structure” or a building or structure “at sea” according to the LP framework, Japan is prohibited from discharging any radioactive waste through it. Japan’s argument at the meetings show that it is trying to circumvent international law by building the undersea tunnel to discharge the radioactive wastewater into the sea, which legally it cannot.

Considering the likelihood of deleterious effects caused by radioactive substances which cannot be treated by the ALPS process, all sources of pollution, including pollution from the radioactive wastewater, can be brought under UNCLOS regulations. Besides, the legitimacy of Japan’s actions depends on whether it wishes to fulfill its procedural obligations on marine environmental pollution under the UNCLOS.

International jurisprudence also shows that dumping radioactive contaminated water into the sea is a gross violation of the basic principles of marine environmental protection, such as the precautionary principle, and the principles of due diligence and state responsibility for causing trans-border damage, and the principle of international cooperation.

The discussion on the legal approaches to Japan’s decision to release the contaminated wastewater cannot be separated from the question of compliance and enforcement. Shortly after Japan’s decision was announced in 2021, the Republic of Korea said it was considering effective ways to respond to it, including approaching the International Tribunal for the Law of the Sea.

The countdown to Japan’s discharge has begun, and a Chinese environmental NGO based in Suzhou, Jiangsu province has already taken the matter to the Chinese maritime court in May. But past post-nuclear accident claim cases and domestic litigation following the Fukushima nuclear power plant accident show the settlement of claims filed by individuals or NGOs against foreign companies or governments can be a long-drawn process.

If Japan succeeds in its plan, it will be the first case of deliberately polluting the oceans by dumping radioactive contaminated water and causing intractable damage to the marine ecosystem and human health.

No matter how difficult it is, for the sake of the marine environment and ecology, legal measures cannot and should not be ignored to prevent Japan from going ahead with its devastating contaminated water discharge plan.

The author is an associate researcher at Koguan Law School of Shanghai Jiaotong University.

The views don’t necessarily reflect those of China Daily.